JP2005164567A - Apparatus for measuring electrical characteristics of array antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To measure input impedance values or far-field directivity of an array antenna and to calculate respective admittance values among antenna elements, on the basis of the measured values. <P>SOLUTION: A prescribed nominal reactance value and first/second deviation reactance values defined by the variations from the nominal reactance value are set to each of variable reactance elements 12-m connected to a passive element Am of an array antenna device 100, and a plurality of input impedance values of the array antenna device 100 are measured. Then, a plurality of variable transformation admittance values are calculated on the basis of the respective measured input impedance values, by using a relational expression which relates to the plurality of variable transformation admittance values and is subjected to a variable transforming processing so as to include respective input impedance values, the first/second deviation reactance values, the nominal reactance value, and the admittance values between respective antenna elements A0-A6 of the array antenna. Respective admittance values between the antenna elements A0-A6 are calculated, by subjecting respective calculated variable transformed admittance values to inverse variable transformation. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an apparatus for measuring the electrical characteristics of an array antenna comprising a plurality of antenna elements and capable of calculating the electrical characteristics of an array antenna having variable directivity characteristics, and in particular, an electronic control waveguide. The present invention relates to an apparatus for measuring the electrical characteristics of an array antenna that can change the directivity of an array antenna apparatus (Electronically Steerable Passive Array Radiator Antenna).

  Prior art electronically controlled waveguide array antenna devices have been proposed in, for example, Patent Document 1 and Non-Patent Documents 1 to 4. The array antenna apparatus is connected to a feed element to which a radio signal is fed, at least one parasitic element that is provided at a predetermined interval from the feed element and to which no radio signal is fed, and the parasitic element. The array antenna including the variable reactance element is provided, and the directivity of the array antenna can be changed by changing the reactance value of the variable reactance element. In this electronically controlled waveguide array antenna device, an inexpensive variable-capacitance diode can be used as a variable reactance element, and since it can be configured with a single feeding system, a compact, lightweight, and low-cost adaptive antenna can be realized. . In addition, since a variable capacitance diode is used with a reverse bias voltage, the power consumption is low, and since a spatial beam is formed, a high dynamic range can be obtained without circuit loss.

JP 2001-24431A. Takashi Ohira et al., “Electronic control of antenna directivity: Adaptive array from the viewpoint of high-frequency hardware design”, IEICE Transactions, IEICE, 83, 12, pp. 920-926, December 2000. Takashi Ohira, “Espato Antenna Equivalent Weight Vector and Array Factor Expression”, IEICE Technical Report, AP2000-44, SAT2000-41, MW2000-44, pp. 7-12, July 2000. Junichi Iigusa et al., “Equivalent Steering Vector and Equivalent Weight Vector Considering ESPAR Antenna's Finite Ground Plane”, IEICE Technical Report, IEICE, AP2003-13, pp. 73-80, April 2003. Junichi Iigusa et al., “Method for calculating structural parameters of ESPAR antenna from far field”, IEICE Technical Report, IEICE, AP2003-35, pp. 53-60, May 2003. Takashi Ohira et al., “Basic formulation of ESPAR antenna beam forming and reactance domain signal processing”, IEICE technical report, IEICE, AP2003-112, pp. 99-104, August 2003. Junichi Iigusa et al., “Extraction of ESPAR antenna equivalent steering vector model parameters and calibration of varactor control characteristics by far-field measurement”, IEICE technical report, IEICE publication, AP2003-40, pp. 111-116, August 2003. Han Qing et al., “Extraction of equivalent weight vector model parameters and calibration of varactor control characteristics of ESPAR antenna by pole near field measurement”, IEICE Technical Report, IEICE, AP2003-113, pp. 105-110, July 2003.

  As described in Non-Patent Document 1, the electronically controlled waveguide array antenna device is an antenna that can change directivity by controlling the reactance value of a variable reactance element. Antenna characteristics such as directivity and input impedance can be calculated by the method of moments or the ICT (improved circuit theory) method, but it is necessary to repeat the calculation every time the reactance value changes. However, since there is a structural parameter determined by the antenna structure independently of the reactance value, once it is obtained, directivity, input impedance, and the like can be easily calculated using only the reactance value as a change amount. Several mathematical models on which such calculation methods are based have been proposed (see Non-Patent Documents 2 and 3). In order to accurately calculate the antenna characteristics under all combinations of reactance values, a mathematical model that can consider all the structural characteristics of the antenna is required. The equivalent steering vector model is an accurate mathematical model in which the admittance value (or impedance value) between the element ports and the equivalent steering vector are structural parameters and the influence of a ground conductor or the like having a finite area can be taken into consideration (see Non-Patent Document 3). ). The structural parameter can be calculated by an analysis method such as the moment method. However, the electronically controlled waveguide array antenna apparatus has a circuit board for loading the variable reactance element, and it is difficult to accurately consider and dimension the antenna housing such as the circuit board and the radome. Therefore, it is not necessary to perform complicated operations such as dimensioning, and the antenna structure parameter measurement method can calculate the antenna measurement when an arbitrary reactance value set is set only by measuring the target antenna once. It is desirable to provide a measuring device.

  Further, in the electronically controlled waveguide array antenna device, since variable reactance elements are loaded on each antenna element, the symmetry of the antenna is electrically broken due to element variations and mounting variations, and individual differences also occur. Accordingly, it is desirable to provide an antenna structural parameter measurement method and measurement apparatus that can measure the control characteristics of a mounted variable reactance element in consideration of the above-described variations.

  Furthermore, Non-Patent Document 4 proposes a method of calculating a structural parameter from 12 pieces of measurement data using the mechanical symmetry of a 7-element electronically controlled waveguide array antenna device, but it is equal to the actual measurement value. The directivity can not be calculated. This is thought to be due to the loss of electrical symmetry in the antenna. Therefore, it is desirable to provide a method and apparatus for measuring structural parameters that do not assume the electrical symmetry of the antenna. Furthermore, it is desirable to make the calculated values of the input impedance and far field directivity of the array antenna device calculated based on the structural parameters more accurate.

  The first object of the present invention is to solve the above-described problems, and to express an admittance matrix composed of admittance values between antenna elements in an electronically controlled waveguide array antenna device and an electric field directivity of the array antenna device. An object of the present invention is to provide an apparatus for measuring the electrical characteristics of an array antenna, which can easily and accurately calculate the structural parameters of the array antenna apparatus including an equivalent steering vector.

  It is a second object of the present invention to provide an apparatus for measuring the electrical characteristics of an array antenna, which can measure the impedance value of a variable reactance element loaded on each parasitic element of the electronically controlled waveguide array antenna apparatus. is there.

  The third object of the present invention is to further calculate the electrical characteristics of the array antenna capable of calculating the input impedance and / or the electric field directivity of the array antenna apparatus based on the measured structural parameters of the array antenna apparatus. It is in providing a measuring device.

  The fourth object of the present invention is to provide an array antenna that can more easily calculate the input impedance and / or the electric field directivity of the array antenna apparatus based on the measured structural parameters of the array antenna apparatus. An object of the present invention is to provide an apparatus for measuring electrical characteristics.

An apparatus for measuring electrical characteristics of an array antenna according to a first invention of the present application includes a feeding element for transmitting and receiving a radio signal,
At least one parasitic element provided at a predetermined interval from the feeding element;
And at least one variable reactance element connected to each parasitic element,
By setting a control voltage for each of the variable reactance elements and changing a reactance value of each of the variable reactance elements, the directivity characteristics are changed by operating each parasitic element as a director or a reflector. An apparatus for measuring the electrical characteristics of an array antenna,
The array antenna is configured to apply at least three control voltages to each of the variable reactance elements, and in a plurality of first control states of all combinations of the control voltages for the variable reactance elements. Means for measuring the input impedance of
Based on the measured input impedance and the impedance value of the variable reactance element viewed from each parasitic element in each first control state, the array antenna feeding element and at least one parasitic element are The relationship which shows the relationship between the admittance value or impedance value between each antenna element of a plurality of including antenna elements, the impedance value of each variable reactance element viewed from each parasitic element, and the input impedance of the array antenna And a means for calculating an admittance value or an impedance value between the antenna elements using an equation.

An apparatus for measuring the electrical characteristics of an array antenna according to the second invention of the present application includes a feeding element for transmitting and receiving a radio signal,
At least one parasitic element provided at a predetermined interval from the feeding element;
And at least one variable reactance element connected to each parasitic element,
By setting a control voltage for each of the variable reactance elements and changing a reactance value of each of the variable reactance elements, the directivity characteristics are changed by operating each parasitic element as a director or a reflector. An apparatus for measuring the electrical characteristics of an array antenna,
The array antenna is configured to apply at least three control voltages to each of the variable reactance elements, and in a plurality of second control states of all combinations of the control voltages for the variable reactance elements. Means for measuring the input impedance and far-field directivity of
Based on the measured input impedance and far field directivity, and the impedance value of the variable reactance element viewed from each parasitic element in each second control state, at least one feeding element of the array antenna The admittance value or impedance value between the antenna elements of the plurality of antenna elements including the parasitic elements, the equivalent steering vector of the array antenna, and the impedance values of the variable reactance elements viewed from the parasitic elements, respectively And means for calculating an equivalent steering vector of the array antenna and an admittance value or an impedance value between the antenna elements, using a relational expression indicating a relation between the input impedance of the array antenna and a far field directivity characteristic. It is characterized by having.

Furthermore, the measurement apparatus for the electrical characteristics of the array antenna according to the third invention of the present application is the measurement apparatus for the electrical characteristics of the array antenna according to the first or second invention.
The array antenna in the third control state when the variable reactance element connected to one parasitic element is set to apply a control voltage whose impedance value of the variable reactance element is unknown. Means for measuring the input impedance of
Based on the input impedance measured in the third control state and the calculated admittance value or impedance value between the antenna elements, the admittance value or impedance value between the antenna elements, A relational expression indicating the relationship between the impedance value of each variable reactance element viewed from the port of the feed element and the input impedance of the array antenna is used to determine whether the variable reactance element connected to the variable reactance element in the third control state is connected. And a means for calculating the impedance value of the variable reactance element as viewed from the power feeding element.

Furthermore, an apparatus for measuring electrical characteristics of an array antenna according to a fourth invention of the present application is the apparatus for measuring electrical characteristics of an array antenna according to the second invention,
The array antenna in the fourth control state when the variable reactance element connected to one parasitic element is set to apply a control voltage whose impedance value of the variable reactance element is unknown. Means for measuring the far-field directivity in a predetermined direction of
Based on the far-field directivity characteristics of the array antenna in a predetermined direction measured in the fourth control state, the measured equivalent steering vector of the array antenna, and the admittance value or impedance value between the antenna elements. The relationship between the admittance value or impedance value between the antenna elements, the equivalent steering vector and far-field directivity of the array antenna, and the impedance values of the variable reactance elements viewed from the ports of the parasitic elements, respectively. And a means for calculating an impedance value of the variable reactance element viewed from a parasitic element connected to the variable reactance element in the fourth control state using the relational expression shown.

Furthermore, an apparatus for measuring the electrical characteristics of an array antenna according to a fifth invention of the present application includes a feeding element for transmitting and receiving a radio signal,
At least one parasitic element provided at a predetermined interval from the feeding element;
And at least one variable reactance element connected to each parasitic element,
By setting a control voltage for each of the variable reactance elements and changing a reactance value of each of the variable reactance elements, the directivity characteristics are changed by operating each parasitic element as a director or a reflector. An apparatus for measuring the electrical characteristics of an array antenna,
The admittance value or impedance value between the antenna elements measured using the measuring device for measuring the electrical characteristics of the array antenna according to the first or second invention, and the electricity of the array antenna according to the third or fourth invention Based on the impedance value of the variable reactance element as viewed from the parasitic element connected to the variable reactance element in the third control state or the fourth control state measured using the measurement device of the mechanical characteristics, Using the relational expressions indicating the relationship between the admittance value or impedance value between the antenna elements, the impedance value of each variable reactance element viewed from the parasitic elements, and the input impedance of the array antenna, Input impedance in the fifth control state in which predetermined control voltages are set for the parasitic elements, respectively. Characterized by comprising a means for calculating the value.

Furthermore, an apparatus for measuring the electrical characteristics of an array antenna according to a sixth invention of the present application includes a feeding element for transmitting and receiving a radio signal,
At least one parasitic element provided at a predetermined interval from the feeding element;
And at least one variable reactance element connected to each parasitic element,
By setting a control voltage for each of the variable reactance elements and changing a reactance value of each of the variable reactance elements, the directivity characteristics are changed by operating each parasitic element as a director or a reflector. An apparatus for measuring the electrical characteristics of an array antenna,
An equivalent steering vector of the array antenna and an admittance value or impedance value between the antenna elements measured using the measuring device for the electrical characteristics of the array antenna according to the second invention, and the array antenna according to the fourth invention Of the array antenna based on the impedance value of the variable reactance element as viewed from the parasitic element connected to the variable reactance element in the fourth control state measured using the electrical characteristic measuring device Relational expression showing the relationship between the steering vector, the admittance value or impedance value between each antenna element, the impedance value of each variable reactance element viewed from each parasitic element, and the far field directivity of the array antenna Each of the parasitic elements is used for each control. Characterized by comprising a means for calculating a far field directional characteristics of the array antenna in the sixth control state of pressure is set.

  The apparatus for measuring electrical characteristics of an array antenna according to the present invention can calculate the admittance value between the antenna elements of the array antenna with high accuracy by measuring the input impedance of the array antenna.

  Further, according to the apparatus for measuring the electrical characteristics of the array antenna according to the present invention, the equivalent steering vector of the array antenna can be calculated with high accuracy by measuring the electric field of the array antenna.

  According to the array antenna electrical characteristic measuring apparatus of the present invention, the admittance value between the antenna elements of the array antenna can be calculated with high accuracy and more easily by measuring the input impedance of the array antenna. Can do.

  Further, according to the apparatus for measuring the electrical characteristics of an array antenna according to the present invention, the equivalent steering vector of the array antenna can be calculated with high accuracy and more easily by measuring the electric field of the array antenna.

  Embodiments according to the present invention will be described below with reference to the drawings.

<First Embodiment>
FIG. 1 is a block diagram showing a configuration of an array antenna control apparatus including an array antenna apparatus 100 which is an electronically controlled waveguide array antenna apparatus according to a first embodiment of the present invention. As shown in FIG. 1, the array antenna control apparatus of this embodiment includes one feed element A0 and six parasitic elements A1 to A6 each loaded with variable reactance elements 12-1 to 12-6. The array antenna apparatus 100 including the ground conductor 11 and the adaptive control controller 20 are configured.

  According to the array antenna electrical characteristic measurement method of the first example of the first embodiment of the present invention, the input impedance of the array antenna apparatus 100 is measured using the measurement calculation system of FIG. Thus, the admittance value between the antenna elements including the feeding element A0 and the parasitic elements A1 to A6 of the array antenna apparatus 100 is calculated with high accuracy. Further, according to the measurement method of the electrical characteristics of the array antenna that is the second example of the first embodiment according to the present invention, the far field pointing of the array antenna apparatus 100 using the measurement calculation system of FIG. By measuring the property (electric field), an equivalent steering vector having an expansion function representing the directivity of each antenna element A0 to A6 of the array antenna apparatus 100 as an element is calculated with high accuracy.

  Here, the adaptive control type controller 20 is configured by a digital computer such as a computer, for example, and is included in a radio signal transmitted from the counterpart transmitter before starting radio communication by the demodulator 4 at the time of reception. A learning signal generated by the learning sequence signal generator 21 having the same signal pattern as the learning sequence signal and the received signal y (t) when the learning sequence signal is received by the feeding element A0 of the array antenna apparatus 100. Based on the sequence signal r (t), for example, adaptive control processing by the steepest gradient method is executed. In this adaptive control processing, bias voltages applied to the variable reactance elements 12-1 to 12-6 for directing the main beam of the array antenna apparatus 100 in the direction of the desired wave and directing null in the direction of the interference wave Search for a value. The control voltage controller 30 is composed of a digital computer such as a computer, for example, and refers to the control voltage table memory 31 on the basis of the control signal from the adaptive control type controller 20, and controls the direct current corresponding to the searched bias voltage value. A voltage signal is output to each variable reactance element 12-1 to 12-6 and set. Although the steepest gradient method is used in the above description, the present invention is not limited to this, and other adaptive control methods may be used.

  In FIG. 1, an array antenna device 100 is composed of seven antenna elements provided on a ground conductor 11, that is, a feeding element A0 and parasitic elements A1 to A6. The feeding element A0 is on the circumference of a radius r. Are arranged so as to be surrounded by six parasitic elements A1 to A6. Preferably, the parasitic elements A1 to A6 are provided on the circumference of the radius r so as to be equidistant from each other (that is, spaced apart from each other at an equal angle with respect to the feeding element A0). Each of the feeding elements A0 and the parasitic elements A1 to A6 is configured to be a monopole element having a length of about λ / 4 with respect to the wavelength λ of the desired wave, for example, and the radius r is λ / 4. Configured to be. Each antenna element has a diameter of 0.02λ. The feeding point of the feeding element A0 is connected to the low noise amplifier (LNA) 1 via the coaxial cable 5 and the circulator 6, and the parasitic elements A1 to A6 are connected to the variable reactance elements 12-1 to 12-6, respectively. These variable reactance elements 12-1 to 12-6 change their reactance values in response to a control voltage signal from the control voltage controller 30.

  FIG. 2 is a longitudinal sectional view of the array antenna device 100. The feeding element A0 is electrically insulated from the ground conductor 11, and the parasitic elements A1 to A6 are grounded at a high frequency with respect to the ground conductor 11 via the variable reactance elements 12-1 to 12-6. The operation of the variable reactance elements 12-1 to 12-6 will be described. For example, when the longitudinal lengths of the feed element A0 and the parasitic elements A1 to A6 are substantially the same, for example, the variable reactance element 12-1 Is inductive (L property), the variable reactance element 12-1 becomes an extension coil, and the electric lengths of the parasitic elements A1 to A6 are longer than those of the feeder element A0, and function as a reflector. On the other hand, for example, when the variable reactance element 12-1 has capacitance (C-type), the variable reactance element 12-1 becomes a shortening capacitor, and the electrical length of the parasitic element A1 is shorter than that of the feeder element A0. Acts as a director. The parasitic elements A2 to A6 connected to the other variable reactance elements 12-2 to 12-6 operate in the same manner.

  Therefore, in the array antenna apparatus 100 of FIG. 1, the reactance that is the junction capacitance value is changed by changing the bias voltage value applied to the variable reactance elements 12-1 to 12-6 connected to the parasitic elements A1 to A6. By changing the value, the plane directivity of the array antenna apparatus 100 can be changed.

  A transmitting station that transmits a radio signal received by the array antenna 100 includes digital data having a predetermined symbol rate including a learning sequence signal having the same signal pattern as the predetermined learning sequence signal generated by the learning sequence signal generator 21. According to the signal, a radio frequency carrier signal is modulated using a digital modulation method such as BPSK or QPSK, and the modulated signal is amplified and transmitted to the array antenna apparatus 100 of the receiving station. In this embodiment, before performing data communication, a radio signal including a learning sequence signal is transmitted from the transmitting station to the receiving station, and adaptive control processing by the adaptive control type controller 20 is executed at the receiving station.

  The array antenna apparatus 100 receives a radio signal from a transmitting station, and the received signal is input to a low noise amplifier (LNA) 1 through a feeding coaxial cable 5 and a circulator 6 and amplified, and then downed. The converter (D / C) 2 performs low-frequency conversion of the amplified signal into a signal having a predetermined intermediate frequency (IF signal). Further, the A / D converter 3 A / D converts the low-frequency converted analog signal into a digital signal, and outputs the digital signal to the adaptive control controller 20 and the demodulator 4. Next, the adaptive control type controller 20 sequentially perturbs the reactance value of each variable reactance element by a predetermined difference width based on the input received signal y (t) and the learning sequence signal r (t). A predetermined evaluation function value (for example, received signal power) is calculated with respect to the reactance value, and the evaluation function value is maximized using the steepest gradient method based on the calculated evaluation function value. In addition, by repeatedly calculating each reactance value, the reactance value of each variable reactance element for directing the main beam of the array antenna apparatus 100 toward the desired wave and the null toward the interference wave is calculated. Control to set. Thus, the bias voltage value of each variable reactance element for directing the main beam of the array antenna apparatus 100 in the direction of the desired wave and the null in the direction of the interference wave is searched so that the evaluation function value becomes maximum. Then, a control voltage signal having each searched bias voltage value is output to each variable reactance element and set.

  The radio transmitter 7 modulates a radio carrier wave by a predetermined modulation method based on the input transmission baseband signal, and the radio signal that is the modulated radio carrier wave is arrayed via the circulator 6 and the feeding coaxial cable 5. The signal is output to the feeding element A0 of the antenna device 100, and a radio signal is radiated from the array antenna device 100.

  Hereinafter, a method for measuring and calculating the structural parameters of the array antenna apparatus 100 will be described.

First, an outline of the equivalent steering vector model of the array antenna apparatus 100 will be outlined, and the structural parameters of the array antenna apparatus 100 will be introduced based on the equivalent steering vector model. FIG. 3 is a schematic diagram showing a comparison between a method for measuring and calculating the electrical characteristics of the array antenna apparatus according to the present embodiment and a method for measuring the near-field using a conventional current measurement probe 300. In the array antenna apparatus 100 is ESPAR antenna, the parasitic element Am (m = 1,2, ..., 6) the reactance value _{X m} of the variable reactance element 12-m to be loaded in, DC By controlling with a bias voltage (hereinafter referred to as a control voltage) V _DCm , the antenna directivity (that is, the far-field electric field) E (θ, φ) is changed. Therefore, the current flowing through each antenna element A0 to A6 is an unknown that cannot be directly controlled.

FIG. 3 shows the relationship of parameters represented by an equivalent steering vector model. Port current i _m which is illustrated in the array antenna apparatus 100 terminal pair circuit element is connected, such as feeding the coaxial cable 5 and the variable reactance elements 12-1 to 12-6 on each antenna element (or port) Current value. Relationship of the reactance value _{X m} and the port current _{i m} is determined by the impedance value Zs inter-port impedance value _{Z mn} and the feeder circuit. Port current i _m a directional (i.e., far-field electric field) E (theta, phi) the relationship between the element u _{m i} ^{(θ, φ)} of equivalent steering vector referred in detail later by determined. The impedance values Z _mn and Zs and the elements u _m ⁱ (θ, φ) of the equivalent steering vector are structural parameters that do not depend on the reactance value X _m . Further, dependence on the control voltage value _{V DCm} reactance value _{X m} of the variable reactance element 12-m is determined by the characteristics of the variable reactance element 12-m. It is an object of this embodiment to obtain these intrinsic parameters by measurement.

As a conventional measuring method, by measuring the port current i _m directly, it is possible to determine the impedance value Z _mn and the variable reactance value X _m. However, this conventional measurement method requires the current measurement probe 300. In the present embodiment, the measurement of the input impedance value Zin by the network analyzer 40 of FIGS. 11 and 16 and the directivity (that is, the far-field of the far-field directivity measurement) by the pattern measurement device such as the measurement calculation system of FIG. A method for calculating the structural parameters of the array antenna apparatus 100 from the measurement of the electric field E (θ, φ) is proposed. However, with respect to each variable reactance element 12-m, it is assumed that the relative value of each reactance value when two control voltage values are respectively input with respect to a predetermined reference reactance value is known.

FIG. 4 is a table comparing the method of measuring and calculating the electrical characteristics of the array antenna apparatus of the present embodiment shown in FIG. 3 and the conventional pole near-field measurement method (that is, current measurement method). In the measurement and calculation method using the input impedance value of the present embodiment as measurement data, the impedance matrix [Z _mn ] (or the inverse matrix of the impedance matrix [Z _mn ]) of the array antenna device 100 is used as the structural parameter of the array antenna device 100. An admittance matrix [Y _mn ]) can be calculated. Further, in the measurement and calculation method using the far-field data of this embodiment as the measurement data, the equivalent steering vector [u _m ⁱ (φ)] of the array antenna device 100 can be calculated as the structure parameter of the array antenna device 100.

Next, variable conversion for virtually short-circuiting the ports of the array antenna apparatus 100 is introduced. As will be described in detail later, in the present embodiment, an expression form in which a function E (θ, φ) representing directivity (that is, a far-field electric field) is expanded with an expansion function unique to the antenna structure is used. In this representation, directivity, each antenna element Am (m = 1,2, ..., 6) as a function of a plurality of the expansion functions linear combination to port current i _m or the port voltage v _m the expansion coefficient of the Expressed. A port current or a port voltage can be used as the expansion coefficient. Expand the port current i _m a coefficient function ^{_{u m i (θ, φ)}} (m = 1,2, ..., 6) is directed in the case of opening another port supplying a current of 1A only for each port It is a function. On the other hand, the expansion function u _m ^v (θ, φ) with the port voltage v _m as a coefficient is a directivity function when a voltage of 1 V is applied only to each port and the other ports are short-circuited. When the port current i _m and expansion coefficients, since the port current i _m to the action of the weight, the expansion functions u _{m i} ^(θ, φ) can also be viewed as elements of a formally steering vector (thus, the present application In the specification, a vector [u _m ⁱ (θ, φ)] composed of a plurality of expansion functions is called an equivalent steering vector.)

  Here, in the conventional equivalent weight vector model disclosed in Non-Patent Document 3 or the like, a point on the antenna element is a port, but each port is fixed to each antenna element Am in the array antenna apparatus 100. If it is, it may be in a part other than the antenna element. Hereinafter, the port position arbitraryness and variable reactance element control characteristics will be described with reference to FIGS.

  FIG. 5 is a schematic diagram showing the port position p1 in the parasitic element Am of the array antenna apparatus 100 of FIG. A general port position p <b> 2 of the equivalent weight vector model is provided on the parasitic element Am at an end portion near the ground conductor 11. A general port position p3 of the equivalent steering vector model is provided at the same position as the variable reactance element 12-m. However, in the equivalent steering vector model of the present embodiment, the port position is arbitrary. In FIG. 5, when a connection line (for example, distributed constant line L1) exists between the variable reactance element 12-m and the parasitic element Am, the port position p1 may be set anywhere on the line. However, the port position p1 needs to be fixed. By changing the port position p1, not only the impedance on the variable reactance element 12-m side is shifted, but also when the connection line is the distributed constant line L1, the impedance value when the variable reactance element 12-m is viewed from the port is variable. This is because the dependence on the reactance value also changes. This is shown in FIGS. 6 to 8 show the reactance value versus impedance value characteristics when the distances δ = λ / 10, δ = λ / 20, and δ = 0 between the port positions p1 and p3 in FIG. 5, respectively. It is a graph which shows.

Therefore, in the case of a normal array antenna, if the feeding connector portion of each antenna element is used as a port, opening and short-circuiting can be realized, so that the equivalent steering vector can be directly measured. However, in the array antenna device 100 which is an electronically controlled waveguide array antenna device, the variable reactance elements 12-1 to 12-6 are loaded on the parasitic elements A1 to A6, so that the ports are opened or short-circuited. I can't. Therefore, it is necessary to obtain an equivalent steering vector by calculation from the directivity of an appropriate reactance value set. In order to simplify the calculation by virtually realizing the short circuit of the port, variable conversion is introduced. In this variable conversion, the conversion indicated by the portion surrounded by the broken line in FIG. 3 is performed. This method is described in Non-Patent Document 4 (the definitions of the equivalent steering vector elements ua ⁱ _m and ua ^v _m are opposite to those in the present specification). Organize and write down.

  In this variable conversion, as a precondition, it is assumed that two reactance fluctuation values are known for each variable reactance element 12-m. In the measurement calculation processing of the structure parameter of the array antenna, which will be described later in detail, three control voltage values are used to control each variable reactance element 12-m, and among these three control voltage values, the variable reactance element at one voltage is used. The element impedance value of 12-m (hereinafter, the impedance value of the element of the variable reactance element itself is referred to as the element impedance value) is used as a reference value, and the element impedance value of the variable reactance element 12-m at the remaining two control voltages is respectively set. It is expressed as a fluctuation value from a reference value, and these two fluctuation values are known for each variable reactance element 12-m.

  However, in the calculation, since the variable reactance element 12-m loaded on each parasitic element Am cannot be removed and directly measured, the value obtained by measuring the variable reactance element 12-m of the same type is used. Therefore, when this value is used, a common value is used for all the variable reactance elements 12-m.

  If there is a variation in the attachment of the variable reactance element 12-m, it appears as a variation in the reference value. If there is no variation in the element performance of the variable reactance element 12-m, the variation value of the element impedance value of the variable reactance element 12-m. Is considered uniform. That is, the assumption that the variation value is known is less restrictive than the assumption that the element impedance value itself is known, and leaves a degree of freedom with respect to variations in the attachment of the variable reactance element 12-m.

  In the following description, for the sake of simplicity, only the reactance value is considered as the element impedance value of the variable reactance element.

The connector connected to the feeding element A0 is regarded as a port of the feeding element, and each connection point close to the variable reactance elements 12-1 to 12-6 loaded on the parasitic elements A1 to A6 is defined as the parasitic elements A1 to A6. (Refer to FIG. 5). Further, the number of parasitic elements Am is generalized to M (m = 1, 2,..., M), and numbers indicating the antenna elements are represented by m, n, and k. A number indicating the power feeding element Am is m = n = k = 0. Current i _m flowing through the ports of the antenna element Am, the impedance matrix of the impedance value Z _mn between ports of an array antenna apparatus with elements and [Z _mn], using a variable reactance value X _m as in equation 1 expressed.

Here, the reactance matrix [X _mn ] is a diagonal matrix of formula 2, and the vector [vs _n ] is a vector of formula 3 having M + 1 elements.

Here, vs is an open circuit voltage of the power feeding circuit. In Equation 1, it can be seen that the impedance matrix [Z _mn ] of the antenna unit is equivalent to the reactance matrix [X _mn ] of the circuit unit. Therefore, by introducing a variable conversion as follows, we define a variable transformed variables converted reactance values Xa _m and variables transformed variables transformed impedance value Za _m. Note that the inverse process of the variable conversion is referred to as inverse variable conversion.

In the present specification, X _m ^{(0) is referred} to as a reference reactance value. The reference reactance value X _m ⁽⁰⁾ is an arbitrary value within a range in which the reactance can be changed (having a minimum value X _m ^(min) and a maximum value X _m ^(max)) , and the value itself may be unknown. Absent.

In the measurement and calculation method of the electrical characteristics of the array antenna apparatus 100 according to the present embodiment, the first and second reactance values X different from the reference reactance value X _m ⁽⁰⁾ are provided for each variable reactance element 12-m. _m ^(a) and X _m ^(b) are used as fluctuation values from the reference reactance value X _m ⁽⁰⁾ . Also herein, refers to Xa _m and shift reactance value, which is the reactance value X _m is meant that expressed in deviation (variation) from the reference reactance value X _{m ^(0).} Therefore, the reference reactance value X _m ⁽⁰⁾ is 0 in the expression of the shift reactance value, and the reactance values X _m ^(a) and X _m ^(b) are respectively expressed in the expression of the shift reactance value Xa _m ^(a) , Xa _m ^(b) (also referred to as first and second shift reactance values). Similarly, the Za _m of variable transformation impedance value.

Expression 1 can be transformed into Expression 7 to Expression 9 by the variable conversion of Expression 4 and Expression 5. Here, the matrix [Xa _mn ] is a shift reactance matrix obtained by substituting the shift reactance values Xa _m (m = 1, 2,..., M) into the reactance values X _m on the right side of Equation 2. Yes, the matrix [Za _mn ] is a variable transformation impedance matrix equal to the impedance matrix [Z _mn ] in which only the diagonal elements Z ₁₁ , Z ₂₂ ,..., Z _MM are replaced with the variable transformation impedance value Za _mm of Equation 5. is there.

Voltage vector [va _n] is a function of the deviation reactance values Xa _m, the element _{va m (m = 1,2, ...} , M) is called shift voltage value herein.

9, parasitic elements Am (m = 1,2, ..., M) of the array antenna apparatus 100 is a schematic diagram showing a lumped circuit model for ports in, and a virtual port p4 of the voltage va _m . Even if the above variables conversion, because the port current i _m is not affected, variable transformation does not mean a change in the port location p1. However, as shown in FIG. 9, when the port portion is virtually represented by a lumped constant circuit (the current value is constant regardless of the location), the deviation voltage value va _m is obtained from the variable reactance element 12-m. and a portion 12-m1 corresponding to the reference reactance value _jX ^{m (0),} can be viewed as a voltage value at the portion 12-m @ 2 and divided points p4 corresponding to the shift reactance value jXa _m. That is, the variable change parameter representation such as shift voltage value va _m and shift reactance values Xa _m can be considered as those of the port voltage and expansion coefficients.

Than the number 7 or number 9, but is variable transformed port voltage va _n is unknown a function of the port current i _m, it is possible with the shift reactance values Xa m _{= 0,} regardless of the port current value i _m The variable-converted port voltage value va _n = 0 (that is, the port is short-circuited). Therefore, have a finite value only shift reactance values Xa _m parasitic elements Am, all other shift reactance values _{Xa n = 0 (n ≠ m} ) port current _i ^m in the case of ^(p) is From the relationship of the (m + 1) th column of Equation 7, it is expressed by the following equation.

Here, the variable-converted admittance value (hereinafter referred to as a variable-transform admittance value) Ya _0m is an element of a variable-transform admittance matrix [Y a _mn ] that is an inverse matrix of the variable-transform impedance matrix [Z a _mn ].

Further, port currents when finite shift reactance values Xa _m ^(q) and Xa _n ^(q) are given only to the variable reactance elements 12-m and 12-n of the parasitic elements Am and An (n ≠ m). i _m ^(q) is expressed by the following equation from the relationship of the ⁽ m + 1 ⁾ th column and the (n + 1) th column of Equation 7.

Parasitic element Ak (k ≠ m, k ≠ n) for it on the current also has a finite value, shift reactance values Xa _k of the variable reactance element 12-k is 0, shift voltage value va _k Becomes 0. Therefore, the variable-converted voltage vector [va _n ] on the right side of Equation 8 can be given only by the currents i _m ^(q) and i _n ^{(q) of} Equation 12, and thus the current vector [i _m ] on the left side. Can be solved.

  Next, the structural parameters of the array antenna apparatus 100 by measuring the input impedance value of the array antenna apparatus 100, which is a first example of the measurement and calculation method of the electrical characteristics of the array antenna according to the embodiment of the present invention. The calculation of will be described. In this embodiment, the admittance matrix of the array antenna apparatus 100 is calculated by measuring the input impedance of the array antenna apparatus 100.

The input impedance value of the array antenna apparatus 100 can be measured by connecting a network analyzer 40 (see FIG. 11 or FIG. 16) to a connector portion that is a power feeding port of the power feeding element A0. In order to distinguish variables such as current in this state from the state where a transceiver is connected to a port, “′” is added and displayed. The input impedance value Zin has a relationship with the port current i ₀ ′ of the feed element A0 by the following equation.

Here, vs ′ and Zs ′ are the internal voltage and circuit impedance of the network analyzer 40, respectively. The port current i ₀ ′ varies depending on the voltage vs ′ of the device connected to the power feeding port of the power feeding element A0 of the array antenna device 100, but the ratio thereof does not change. The port current i ₀ ′ is expressed by the following equation from the relationship in the first column of Equation 7.

All of the variable reactance element 12-m (m = 1,2, ..., M) expressed as ^{Zin (0)} the input impedance in the case of a zero shift reactance values Xa _m of, than the number 14 and number 15, A variable conversion admittance value Ya _{00 of the} following equation is calculated.

The input impedance measured when only the shift reactance value of the variable reactance element 12-m is set to the first shift reactance value Xa _m ^(a) and the shift reactance values of the other variable reactance elements are set to 0. The value is set to Zin _m ^(a) , only the shift reactance value of the variable reactance element 12-m is set as the second shift reactance value Xa _m ^(b), and the shift reactance values of the other variable reactance elements are set as the second reactance reactance value. Assuming that the input impedance value measured when set to 0 is Zin _m ^(b) , the variable conversion admittance values Ya _mm and Ya _{0m of} the following equations are calculated from Equations 10, 14, and 15.

Only the variable reactance elements 12-m and 12-n (n ≠ m) are given the shift reactance values of the first shift reactance values Xa _m ^(a) and Xa _m ^(a) , respectively. Assuming that the input impedance measured when the shift reactance value is 0 is Zin _mn ^(a) , the variable conversion admittance value Ya _{mn of the} following equation is calculated from Equations 12, 14, and 15.

ここで、

here,

The input impedance value measurement items necessary for calculating all the variable conversion admittance values Ya _mn are typically classified as shown in the left column of the table of FIG. In the measurement of the classification (0), the measurement values necessary for the calculation of the expression 16 are acquired. Similarly, in the measurement of the classification (i), (ii), and (iii), it is necessary for the calculation of the expressions 17 to 19. To get a good measurement. There are (M + 1) (M + 2) / 2 variable transformation admittance values Ya _mn to be calculated (to be measured and calculated), and the required number of measurements is also 1 + M + M + M (M−1) / 2 = (M + 1) ( M + 2) / 2 times.

Note that the variable conversion admittance value Ya _mn calculated by measurement depends on the impedance value Zs ′ in Equations 16 to 23, but the admittance value Y _mn is independent of the characteristics on the power feeding side, and thus the impedance value Zs. It doesn't depend on '. Since the input impedance of the network analyzer 40 (see FIG. 11) used for measurement is considered to be 50Ω, this value is used for the calculation.

As described above, according to the measurement and calculation method of the electrical characteristics of the array antenna according to the present embodiment, the input impedance value of the array antenna apparatus 100 can be measured and calculated with high accuracy in the next step.
(1-1) All of the variable reactance element 12-m (m = 1,2, ..., M) input impedance ^Zin when the zero shift reactance values Xa _m of the ⁽⁰⁾ was measured, the number 16 Then, the variable conversion admittance value Ya ₀₀ is calculated. (One measurement)
(1-2) For each of the variable reactance elements 12-1 to 12-M, the deviation reactance values Xa _m ^(a) and Xa _m ^(b) are given only to the variable reactance element 12-m, and the deviations of the remaining variable reactance elements are given. transfer reactance values Xa _m 0 and then each of the input impedance value when the _Zin ^m (a), measured _Zin ^{m (b),} the variable conversion admittance value _{Ya mm} than the number 17 is calculated, the number 18 from the variable transformation admittance The value Ya _0m is calculated. (M times + M times measurement)
(1-3) a variable reactance element 12-m and 12-n (n ≠ m) of shift reactance value of each _Xa ^m (a), and _Xa ^{m (a),} 0 the remaining shift reactance values Xa _m The input impedance value Zin _mn ^(a) is measured, and the variable conversion admittance value Ya _mn is calculated from Equations 19 to 23. (M (M-1) / 2 measurements)
(1-4) In order to calculate an admittance matrix or impedance matrix that is not subjected to variable conversion (that is, not a relative value to the reference reactance value X _m ⁽⁰⁾⁾ , the reference value of the impedance of the previous variable reactance element Using the reference reactance value X _m ⁽⁰⁾ , the calculation is performed from Equation 4, Equation 5, Equation 11, and Equation 24.

Since the antenna characteristic can be calculated from the parameter that has been subjected to variable conversion (that is, expressed as a value relative to the reference reactance value X _m ^(0)), it is not always necessary to calculate a parameter that has not been subjected to variable conversion. That is, the antenna characteristic can be calculated even if the reference reactance value X _m ⁽⁰⁾ is unknown.

Here, the arbitraryness of the reactance value in the measurement and calculation of the structural parameter of the array antenna apparatus 100 will be described. For each variable reactance element 12-m (m = 1, 2,..., M), the two values of the shift reactance values Xa _m ^(a) and Xa _m ^(b) need to be known. Since these are relative reactance values from the reference reactance value X _m ⁽⁰⁾ , the actual reactance value X _m ⁽⁰⁾ deviates from the input value due to the lumped impedance due to the influence of the connection portion. However, the variable conversion impedance value Za _mn ^(a) and the variable conversion reactance value Za _m ^(b) do not change. In this case, from Equation 4 and Equation 5, this deviation is included in the variable conversion impedance value Za _mn that is a characteristic of the radiation portion. That is, if there are variations in the deviation of the variable range of the variable reactance element 12-m, the deviation is reflected as asymmetry of the variable conversion impedance value Za _mn. However, when a wiring exists between the port and the variable reactance element 12-m, it is affected by a distributed constant, and the shift reactance values Xa _m ^(a) and Xa _m ^(b) also change depending on the defined port position ( (See FIGS. 5 to 8).

Therefore, in order to obtain the single shift reactance value Xa _m ^(a) as the reactance fluctuation value from the reference reactance value X _m ^{(0) at} the predetermined control voltage V _DCm , the port position p1 has the variable reactance. Must be in proximity to element 12-m. If the reactance fluctuation value of the variable reactance element 12-m alone is slightly deviated from the shift reactance values Xa m ^_(a) in the opposite variation value at the time of using the calculated shift reactance values Xa m ^_(a) is A point having ^a deviation reactance value Xa _m ^(a) is selected as a port. That is, the degree of freedom of the port position p1 is used to set the point where the reactance fluctuation value actually becomes the shift reactance value Xa _m ^(a) as a port.

  In the present embodiment, the port is provided close to the variable reactance element 12-m in order to avoid the fluctuation of the shift reactance value due to the change of the port position.

On the other hand, the reference reactance value X _m ⁽⁰⁾ is necessary when the impedance value Z _mn is calculated according to Equation 5 from the variable conversion impedance value Za _mn that is a structural parameter derived from the measured value. However, the number 5 (i.e. not variable transformation) and the impedance value _{Z mn,} without knowing the reactance value _{X m} by the number 4, a variable transformation impedance value _{Za mn} by shift reactance values Xa _m, the number 7 used correctly calculate the port current i _m, it can further calculate the antenna characteristics. That is, the reference reactance value X _m ⁽⁰⁾ regarding the array antenna apparatus 100 may be arbitrary (unknown). Be considered the reference reactance value _X ^{m (0)} and part of the self input impedance value _{Z mm} of the parasitic element, the variable reactance element 12-m (m = 1,2, ..., M) reactance value _{X m} of the This is because the antenna characteristics are not affected as can be seen from equation (7).

On the other hand, when the impedance value Z _mn (not subjected to variable conversion) is calculated using the reference reactance value X _m ⁽⁰⁾ , the admittance value Y _mn (that is, the admittance matrix [Y _mn ])).

  Next, a method for measuring the control characteristic of the variable reactance element 12-m of the array antenna apparatus 100 by measuring the input impedance value of the array antenna apparatus 100 will be described.

By measuring the input impedance value when only the control voltage of the variable reactance value of one variable reactance element 12-m is changed, the element impedance value (Z _m =) R of the loaded variable reactance element 12-m is measured. _m + jX _m is calculated. Since armed variable reactance element 12-m actually has a resistance component R _m to the other components of the reactance value X _m, which is also calculated by measuring the combined. Thereby, it can be seen how the element impedance value (Z _m =) R _m + jX _m of the loaded variable reactance element 12-m has a dependency on the control parameter (here, the control voltage).

When each element Ya _mn (n, m = 1, 2,..., M) of the variable conversion admittance matrix is determined, the shifted reactance value Xa _n (n ≠ m) other than the variable reactance element 12-m is set to 0. From the measured value Zin _m ^(p) of the input impedance of the variable reactance element 12-m, the variable-transformed element impedance value (hereinafter referred to as the variable conversion element impedance value) Ra _m + jXa _m is expressed by the following equation. Can be calculated.

By measuring the input impedance value _Zin ^{m (p)} while changing the control voltage, to measure the control voltage dependence of the variable variable transducer impedance value of the reactance element _{12-m (Za m =)} Ra m + jXa m it can.

Moreover, the real part of the impedance value of the variable reactance element 12-m of the formula (i.e., a resistance component) is used variable transformation regarding R _m, resulting variable transducer impedance value of the variable reactance element _12-m (Za m = ) From Ra _m + jXa _m , the element impedance value (Z _m =) R _m + jX _m that has not been subjected to variable conversion can be calculated.

Here, R _m ⁽⁰⁾ is a reference resistance value of the variable reactance element 12-m set in the same manner as in Expression 4.

As described above, according to the measurement and calculation method of the electrical characteristics of the array antenna of the present embodiment, the control voltage of the variable reactance element 12-m versus the element impedance value (Z _m =) R _m is obtained by the following procedure. + JX _m characteristics can be measured with high accuracy.
(2-1) In order to investigate the control characteristics of the variable reactance element 12-m loaded in the parasitic element Am, its control parameter (control voltage) is given, and the shift reactance value Xa of the remaining variable reactance elements _{When m is set} to 0, the input impedance value Zin _m ^(p) is measured, and the variable conversion admittance value calculated above is used to calculate the variable conversion element impedance value Ra _m + jXa _m of the variable reactance element from Equation 25. Ask.
(2-2) The control parameter (control voltage V _DCm ) of the variable reactance element 12-m is changed, and the input impedance value Zin _m ^(p) is measured every time the variable reactance element 12-m is changed, and the variable conversion element impedance value Ra of the variable reactance element The control characteristic of _m + jXa _m is obtained.
(2-3) Using the reference resistance value R _m ⁽⁰⁾ and the reference reactance value X _m ⁽⁰⁾ , the control characteristic obtained from Equation 4 and Equation 26 is converted into the element impedance value (Z _m =) R _m + jX Convert to the control characteristic represented by _m .
Thereby, the control voltage versus element impedance value (Z _m =) R _m + jX _m characteristic of the variable reactance element 12-m in the array antenna apparatus 100 can be measured.

  Next, calculation of reactance value versus input impedance value characteristics of the array antenna apparatus based on the structural parameters of the array antenna apparatus 100 measured and calculated as described above will be described.

The impedance matrix [Z _mn ] between the antenna elements A0 to A6 of the array antenna apparatus 100 is measured and calculated by the above-described method, and the element impedance value of each variable reactance element 12-m when an arbitrary control voltage is applied. (Z _m =) R _m + jX _m is measured and calculated according to the method described above. The antenna characteristics when the element impedance value (Z _m =) R _m + jX _m is obtained by calculation of the following steps.

(3-1) to account for the resistance component in the element impedance value of the variable reactance element 12-m, the number of substituting element impedance value _R m + jX _m complex instead of Equations 1 and 2 of the reactance jX _m 27 and the number 28, with the number 3, to calculate the port current i _m.

(3-2) the current _{i 0} of the formula, except the number 14 of the prime "'", to calculate the input impedance value Zin by substituting the values obtained in step (3-1). The case where the network analyzer 40 of FIG. 11 is connected to the port is indicated with “′”.

Note that vs in Equation 3 is the open circuit voltage of the power feeding unit, but the calculation result is the same even if an arbitrary value is used. Further, in the present embodiment, in order to calculate the port current _{i m,} the number 27 and number 28, the element impedance value of the variable reactance element _{12-m (Z m =)} R m + jX m ( i.e., real and imaginary was used.) containing both parts, it may be calculated port current i _m using a reactance value X _m of the variable reactance element 12-m by the number 1 and number 2.

Further, in place of the variable transformations of Equations 4 and 5, the following equation considering both the real part and the imaginary part of the element impedance value of the variable reactance element 12-m (that is, the resistance value R _m and the reactance value X _m ): The variable conversion may be executed.

  After performing such variable conversion, it is possible to calculate the structural parameters of the array antenna apparatus 100 by measuring the input impedance of the array antenna apparatus 100 as in the method described above.

  Next, the array antenna apparatus by measuring the far-field directivity of the array antenna apparatus 100, which is a second example of the method for measuring and calculating the electrical characteristics of the array antenna according to the first embodiment of the present invention. The calculation of 100 structural parameters will be described.

  According to the equivalent steering vector model, when the azimuth angle of the array antenna apparatus 100 is φ and the elevation angle (that is, the tilt angle from the vertical direction) is θ, the electric field E (θ, φ) in the distance is expressed by the following equation. (See Non-Patent Document 3).

Here, in the expression using the shift voltage vector [va _m ] and the variable conversion admittance matrix [Ya _mn ], Expression 33 is expressed as the following equation.

In Non-Patent Document 4, a vector having an expansion function as an element (that is, an equivalent steering vector) [ua _m ^v (θ, φ)] is represented as [ua _m ⁱ (θ, φ)]. In the present specification, hereinafter, the notation of the elevation angle θ is omitted, and unless otherwise noted, the elevation angle θ is 90 degrees. Further, the azimuth angle φ is set to 0 degree in the direction in which the parasitic element A1 is located with respect to the feeder element A0 of the array antenna apparatus 100.

The directivity when the deviation reactance values Xa _m (m = 1, 2,..., M) of all the variable reactance elements 12-m are set to 0 is represented by E ⁽⁰⁾ (φ) = E ⁽⁰⁾ (θ, If φ), the following equation is obtained from Equation 34.

Directivity of array antenna apparatus 100 when only the shift reactance value of variable reactance element 12-m is Xa _m ^{(a) and} the shift reactance value of other variable reactance elements 12-n (n ≠ m) is 0 ( In other words, the far-field electric field) is set to E _m ^(a) (φ) = E _m ^(a) (θ, φ), and only the shift reactance value of the variable reactance element 12-m is set to Xa _m ^(b). The electric field in the azimuth angle φ = φ ₀ direction when the shift reactance value of the element 12-n (n ≠ m) is 0 is expressed as E _m ^(b) (φ ₀ ) = E _m ^(b) (θ, φ ₀ ), The variable conversion admittance value Ya _mm and the midway calculated value ua _m ^v (φ) Ya _{0m of} the following equation are calculated from the relationship of Equation 10 and Equation 34.

From Equation 38, each element ua _m ^v (θ ₀ , φ) (m = 1, 2,..., M) of the variable conversion equivalent steering vector in a certain elevation angle plane (θ = θ ₀ ) is in-plane directivity. It can be calculated from E (θ ₀ , φ) and is determined independently of the directivity in the other elevation planes.

Azimuth angle φ = φ ₀ direction when finite shift reactance values Xa _m ^(a) and Xa _n ^(a) are given only to variable reactance element 12-m and variable reactance element 12-n (n ≠ m ⁾ , respectively Is expressed as E _mn ^(a) (φ ₀ ) = E _mn ^(a) (θ, φ ₀ ), the variable conversion admittance value Ya _{mn of the} following equation is calculated from Equation 12 and Equation 34.

ここで、

here,

Intermediate calculation values Q ₃ and Q ₄ (see Equations 22 and 23) are calculated using Equation 37.

Similar to the above-described embodiment in which the input impedance value is measured and the structural parameters of the array antenna apparatus 100 are calculated, the shift reactance values Xa _m ^(a) and Xa _m ^(b) need to be known. Corresponding measurement items are typically classified as shown in the right column of the table of FIG. In the measurement of the classification (0), the measurement values necessary for the calculation of the expression 36 are obtained. Similarly, in the measurement of the classification (i), (ii), and (iii), the expression 38, the expression 37, and the expression Measurement values necessary for the calculation of 39 to Equation 43 are acquired. The number of far-field directivity measurements is equal to that when measuring the input impedance value, and is (M + 1) (M + 2) / 2 times.

The midway calculated value ua _m ^v (φ) Ya _0m in Equation 38 can be regarded as an equivalent steering vector in which an admittance value is introduced. Here, a method for deriving the element ua _m ^v (φ) of the variable conversion equivalent steering vector from the midway calculated value ua _m ^v (φ) Ya _{0 m} will be described.

Equation 38 gives the product of the variable transformation admittance value Ya _0m and the variable transformation equivalent steering vector element ua _m ^v (φ), and the antenna directivity can be calculated from this product. That is, the variable conversion admittance value Ya _0m can be transferred to the element ua _m ^v (φ) of the equivalent steering vector. However, there is no formula for determining each value. In addition, Expressions 36 to 43 do not have an expression for determining the variable conversion admittance value Ya ₀₀ . In order to calculate a parameter that has not been subjected to variable conversion using Expression 4 and Expression 5, variable conversion admittance values Ya ₀₀ and Ya _0m are necessary. Variable conversion admittance value _{Ya 00,} all of the shift reactance values Xa _m can be determined by the input impedance ^{Zin (0)} was measured number 16 in the case of zero. Further, the variable conversion admittance value Ya _0m is obtained by giving the shift reactance value Xa _m ^(a) to each variable reactance element 12-m with respect to the M variable reactance elements 12-m, and shifting reactances of other variable reactance elements. The input impedance value Zin _m ^(a) when the value is set to 0 is measured, and the variable conversion admittance value Ya _mm that can be calculated from Expression 37 is substituted into Expression 18 for calculation. That is, measurement items of classification (0) and classification (i) relating to input impedance value measurement may be added. Thereby, the following division can be performed to calculate the element ua _m ^v (φ) of the equivalent steering vector.

Next, a method for calculating the transceiver circuit impedance value Zs will be described. In order to calculate the variable conversion admittance values Ya ₀₀ and Ya _0m , the following equation is used in which the impedance value Zs ′ of Equations 16 and 18 is changed to the impedance value Zs of the transceiver unit.

The impedance value Zs is determined because the variable conversion admittance value _Yakk is given by _Equation 37. In order to calculate the impedance value Zs, the input reactance value is measured when the shift reactance value Xa _k ^(b) is given only to the variable reactance element 12-k and the shift reactance values of the other variable reactance elements are set to zero. Run once more. Using the measured input impedance value as Zin _k ^(p) , the impedance value Zs is calculated by the following equation.

ここで、

here,

As described above, according to the measurement and calculation method of the electrical characteristics of the array antenna according to the present embodiment, the equivalent steering vector of the array antenna apparatus 100 is measured by measuring the far-field electric field of the array antenna apparatus 100. Can be calculated. In order to calculate the element u _m ⁱ (θ, φ) of the equivalent steering vector, M + 2 far field directivity measurements are added.

As described above, according to the measurement and calculation method of this embodiment, the structural parameters of the array antenna apparatus 100 can be measured and calculated in the following steps.
(4-1) The far-field electric field E ⁽⁰⁾ (θ, φ) of the array antenna apparatus 100 is measured when the reference reactance values are set for all the variable reactance elements 12-m.
(4-2) When the first shift reactance value Xa _m ^(a) is set in one of the variable reactance elements 12-m and the reference reactance value is set in the other variable reactance elements, The far-field electric field E _m ^(a) (θ, φ) of the array antenna apparatus 100 when the variable reactance element for setting the shift reactance value Xa _m ^(a) is sequentially changed is measured.
(4-3) When the second shift reactance value Xa _m ^(b) is set in one of the variable reactance elements 12-m and the reference reactance value is set in the other variable reactance elements, A far-field electric field E _m ^(b) (θ, φ ₀ ) at a predetermined azimuth angle φ ₀ of the array antenna device 100 when the variable reactance elements for setting the shift reactance value Xa _m ^(b) are sequentially changed. Measure each.
(4-4) When the first shift reactance value Xa _m ^(a) is set in two of the variable reactance elements 12-m and the reference reactance value is set in the other variable reactance elements, Two variable reactance elements 12-m and 12-n (n ≠ m ⁾ for setting one shift reactance value Xa _m ^(a) were sequentially changed so as to include all combinations of the variable reactance elements. The far-field electric field E _mn ^(a) (θ, φ ₀ ) at a predetermined azimuth angle φ ₀ of the array antenna apparatus 100 is measured.
(4-5) The input impedance value Zin ⁽⁰⁾ of the array antenna apparatus 100 when the reference reactance value is set for all the variable reactance elements 12-m is measured.
(4-6) When the first shift reactance value Xa _m ^(a) is set in one of the variable reactance elements 12-m and the reference reactance value is set in the other variable reactance elements, The input impedance value Zin _m ^(a) of the array antenna apparatus 100 when the variable reactance element for setting the deviation reactance value is sequentially changed is measured.
(4-7) Array antenna apparatus 100 when second shift reactance value Xa _m ^(b) is set in one of variable reactance elements 12-m and a reference reactance value is set in another variable reactance element The input impedance value Zin _k ^(b) is measured.
(4-8) The measured electric fields E ⁽⁰⁾ (θ, φ), E _m ^(a) (θ, φ), E _m ^(b) (θ, φ ₀ ), and E _mn ^{(a ) Based on} (θ, φ ₀ ) and the measured input impedance values Zin ⁽⁰⁾ , Zin _m ^(a) and Zin _k ^(b) , the far-field electric field, the input impedance value, , A relational expression between the first and second shift reactance values and an admittance value between the antenna elements including the feeding element A0 and the parasitic elements A1 to A6 of the array antenna apparatus 100 (that is, Expression 37, Expression 39 to Expression 43, Expression 47 to Expression 49, Expression 16, and Expression 18) are used to calculate a variable conversion admittance value that is an admittance value between the antenna elements of the array antenna apparatus 100 associated with the shift reactance value. .
(4-9) Based on each measured far field electric field E ⁽⁰⁾ (θ, φ) and E _m ^(a) (θ, φ) and the calculated variable transformation admittance value, Relational expressions of the far-field electric field, the first shift reactance value, the variable conversion admittance value, and the directivity function of each antenna element of the array antenna apparatus 100 (that is, Equations 36, 38, and 44) is used to calculate an equivalent steering vector having as an element the directivity function of each antenna element of the array antenna apparatus 100 associated with the shift reactance value.
(4-10) When calculating an equivalent steering vector in which no variable is changed, an equivalent steering having the directivity function of each of the antenna elements A0 to A6 of the array antenna apparatus 100 associated with the calculated deviation reactance value as an element Based on the vector and the calculated variable conversion admittance value, the equivalent steering vector of the array antenna is calculated using a relational expression (Equation 35) between the variable conversion admittance value and the equivalent steering vector.

Further, according to the measurement and calculation method of the present embodiment, as a modification, the structural parameters of the array antenna device 100 can be measured and calculated in the following steps.
(4-1 ') of all the shift reactance directional ^E when the Xa _m was 0 ⁽⁰⁾ (phi) is measured to calculate the elements ua ₀ equivalent steering vector from the number 36 (phi). (One measurement)
(4-2 ') variable only reactance element 12-m to give a shift reactance values _Xa ^{m (a),} the remaining shift reactance values Xa _m 0 and the far field directivity _E ^m when ^(a) ( φ) is measured and this measurement is repeated for each variable reactance element 12-m (M measurements).
(4-3 ') with respect to only one variable reactance element 12-k, only the variable reactance element 12-k to give shift reactance values _Xa ^{m (b),} when the remaining shift reactance values Xa _m is 0 The far-field electric field E _k ^(b) (φ ₀ ) at a specific azimuth angle φ ₀ is measured. (One measurement)
(4-4 ′) The variable conversion admittance value Ya _kk is calculated by substituting the measured values of steps (4-2 ′) and (4-3 ′) into the equation where m = k in Equation 37.
(4-5 ′) Using the input impedance values Zin _k ⁽⁰⁾ , Zin _k ^(a) , Zin _k ^(b) measured above and the variable conversion admittance value Ya _kk obtained in step (4-4 ′). Thus, the impedance value Zs of the transceiver unit is calculated from Equation 47.
(4-6 ′) Using the measured value of the input impedance value measurement described above, the impedance value Zs obtained in step (4-5 ′) is substituted for the impedance value Zs ′ in Expressions 16 to 23, and the variable The conversion admittance values Ya ₀₀ , Ya _mm , Ya _0m , Ya _mn are calculated. Since the variable conversion admittance value Y _kk regarding m = k is obtained in step (4-4 ′), no calculation is necessary.
(4-7 ′) Using the electric field E _m ^(a) (φ) that is the measurement value in step (4-2 ′), the midway calculated value ua _m ^v (φ) Ya _0m is calculated from Equation 38.
(4-8 ′) From the variable conversion admittance value Ya _0m obtained in step (4-6 ′), from the intermediate calculation value ua _m ^v (φ) Ya _0m in step (4-7), the variable conversion equivalent steering vector The element ua _m ^v (φ) is calculated.
(4-9 ') to compute the elements u _{m i} of an equivalent steering vector that are not variable transformation ^(phi) is calculated by means of the elements ua m _v number 35 from ^(phi) of the variable conversion equivalent steering vector.

  Next, a method for measuring the control characteristics of the variable reactance element 12-m of the array antenna apparatus 100 by measuring the far-field directivity of the array antenna apparatus 100 will be described.

From the far-field electric field in a certain direction when only the control voltage of the variable reactance value of one variable reactance element 12-m is changed, the element impedance value (Z _m =) R of the loaded variable reactance element 12-m _m + jX _m is measured. (Armed variable reactance element 12-m is determined to suit the actual To have in addition to the resistance component R _m of the components of the reactance value X _m.) Thus, armed of the variable reactance element 12-m It can be seen how the element impedance value (Z _m =) R _m + jX _m has a dependency on the control voltage.

If all the variable conversion admittance values Ya _{mn of the} array antenna apparatus 100 are calculated, the variable reactance can be calculated from the measurement of directivity E _m ^(p) (φ ₀ ) when the reactance value of one variable reactance element 12-m is controlled. The variable conversion element impedance value Ra _m + jXa _m of the element 12-m (m = 1, 2,..., M) can be calculated by the following equation.

By measuring the far-field electric field E _m ^(p) (φ) while changing the control voltage, the control voltage dependence of the variable conversion element impedance value of the variable reactance element can be measured. Furthermore, the number 4 and using a few 26, the control voltage dependence of the number 50 represented by the variable transducer impedance value Za _m, the control voltage dependence represented by the element impedance value Z _m which is not variable transformation Can be calculated.

As described above, according to the method for measuring the control voltage versus element impedance value (or element reactance value) characteristic of the variable reactance element, the characteristic can be measured by the following procedure.
(5-1) In order to investigate the control characteristics of the variable reactance element 12-m loaded on the parasitic element Am, its control parameter (control voltage) is given, and the reactance value Xa _n ( Measure the far-field electric field E _m ^(p) (φ ₀ ) at a specific azimuth angle φ ₀ when n ≠ m) is 0, and use the variable conversion admittance value obtained above, The variable conversion element impedance value Ra _m + jXa _m of the variable reactance element is obtained.
(5-2) The far-field electric field E _m ^(p) (φ ₀ ) is measured while changing the control parameter (control voltage) of the variable reactance element 12-m, and the variable conversion element impedance value Ra _m + jXa of the variable reactance element _Determine the control characteristic of _m .
(5-3) Using the standard reactance value X _m ⁽⁰⁾ , the element impedance value (Z _m =) R _m + jX _m not subjected to variable conversion is converted from Equation 4 and Equation 26.
As a result, the control voltage versus element impedance value (Z _m =) R _m + jX _m characteristic of the variable reactance element 12-m in the array antenna apparatus 100 can be measured with high accuracy.

  Next, calculation of reactance value vs. far-field directivity of the array antenna device based on the structure parameters of the array antenna device 100 calculated by the above measurement will be described.

The impedance value Z _mn between the antenna elements A0 to A6 of the array antenna apparatus 100 and the element u _m ⁱ (θ, φ) of the equivalent steering vector of the array antenna apparatus 100 are obtained in advance as described above. Further, the element impedance value (Z _m =) R _m + jX _m of each variable reactance element 12-m when an arbitrary control voltage is applied is measured and calculated according to the above method. The antenna characteristics when the element impedance value (Z _m =) R _m + jX _m is obtained by calculation of the following steps.
(6-1) to account for the resistance component of the variable reactance element 12-m, the number 3, with the number 27 and number 28, to calculate the port current _{i m.}
(6-2) The number 33 of the current _{i m} to the step (6-1) in obtained by substituting the values directional E (theta, phi) is calculated.
In the calculation of the structural parameter using the far-field directivity measurement, the element u _m ⁱ (θ, φ) of the equivalent steering vector can be calculated in the form of the product of the voltage vs of Equation 3 (vs = 1). The directivity calculation result described above does not depend on the value of the voltage vs.

  In the measurement and calculation methods for the electrical characteristics of the array antennas according to the first and second embodiments described above, the degree of freedom included in the measurement method and some modifications will be described.

In each measurement classification (0), (i), (ii), (iii) of FIG. 10, the measurement items of the input impedance value and the far-field directivity can be exchanged. Further, all the input impedance value measurements in FIG. 10 are performed only (M + 1) (M + 2) / 2 times, the directivity measurement M + 1 times of classification (0) and classification (i), and the classification for obtaining the impedance value Zs. by only performing a single measurement of (ii), all structural parameters _{{Ya mn, ua m, ua} 0, Zs} can be calculated. The number of structural parameters is also (M + 2) (M + 3) / 2, which is the same as the number of measurements. For the element that performs the far field directivity measurement of classification (ii), the variable conversion admittance value _Yakk is calculated from _Equation 37, and the impedance value Zs is calculated from Equation 47 using the value. In the modification of this embodiment, this combination of measurement items is used. Since the number of variable reactance elements M = 6 in the 7-element electronically controlled waveguide array antenna device, 36 measurements are performed.

The reason why the measurement items can be exchanged is that Expression 15, Expression 34, and Expression 35 have the same shape. The directivity (that is, the far-field electric field) E (φ) has an angle dependency, but when fixed to the electric field E (φ ₀ ) with a certain azimuth angle φ ₀ , this electric field E (φ ₀ ) and the input impedance value Zin shows the same dependence on the shift reactance values Xa _m. Therefore, even when measuring these two values, information on shift reactance Xa _m is not increased to 2 times. If more seems, by increasing the number of shift reactance values Xa _m making measurements, it can be solved all the shift reactance values Xa _m easily. Since this is not possible, the shift reactance values Xa _m ^(a) and Xa _m ^(b) are known in the measurement and calculation method of the present embodiment. On the other hand, in the conventional method of measuring the current on each antenna element, for example, the same number of current values as the number of M + 1 elements can be measured. Therefore, by performing several measurements while changing the reactance value, all reactances are measured. it can solve the value X _m as unknowns (see table of FIG. 4).

There are several combinations regarding the exchange of the input impedance value measurement and the far-field directivity measurement in a specific direction, but here are two examples. As a first example, the step (1-3) for calculating the variable conversion admittance value Ya _mn by the input impedance value of the array antenna apparatus 100 is substituted by the following directivity measurement process.
(1-3 ') variable reactance element 12-m and 12-n (n ≠ m) a shift reactance value each _Xa ^m (a), and _Xa ^{n (a),} the rest of the shift reactance values Xa _m A far-field electric field E _mn ^(a) (φ ₀ ) at ^a specific azimuth angle φ ₀ , when set to _0, is measured, and the variable conversion admittance value Ya is calculated from Equation 39 using the variable conversion admittance value obtained above. Calculate _mn . This further requires M (M-1) / 2 measurements.

Next, as a second example, the step (1-2) for calculating the variable conversion admittance value Ya _mm by measuring the input impedance value of the array antenna apparatus 100 is substituted by the next far-field directivity measurement.
(1-2 ') with respect to each of the variable reactance elements 12-1 to 12-M, the variable reactance element 12-m only shift reactance values Xa _m of the remaining variable reactance element given shift reactance values Xa _m ^(a) The directivity E _m ^(a) (φ) is measured when M is 0 (measurement of M times), and the shift reactance value Xa _m ^(b) is given only to the variable reactance element 12-m, and the remaining variable reactance elements the measured shift reactance values Xa _m 0 and the electric field E _m of far-field at a particular azimuth angle phi ₀ when ^{_{(b) (φ 0) (}} M measurements of), the number 37 from the variable conversion admittance value Ya _mm is calculated, and an intermediate calculation value ua _m ^v (φ) Ya _{0 m} is calculated from Equation 38. The electric field E ⁽⁰⁾ (φ) necessary for the calculation of Equations 37 and 38 needs to be obtained by measurement.

Further, in order to obtain the element ua _m ^v (φ) of the variable conversion equivalent steering vector from the midway calculated value ua _m ^v (φ) Ya _0m , the variable conversion admittance value Ya _0m is required. For that purpose, the following step (1-2) ", which is a part of step (1-2), is measured.
(1-2) "with respect to each of the variable reactance element 12-m, and a zero shift reactance values Xa _m of the remaining variable reactance element giving a variable reactance element 12-m only shift reactance values Xa _m ^(a) Input impedance value Zin _m ^(a) is measured, and a variable conversion admittance value Ya _0m is calculated from Equation 18.

  Hereafter, systems for executing the processes related to the measurement and calculation method of the electrical characteristics of the array antenna according to the first and second embodiments described above will be respectively shown.

  FIG. 11 is a block diagram showing the configuration of the structural parameter measurement calculation system of the array antenna apparatus 100 using the input impedance value measurement according to the first example of the first embodiment of the present invention.

  In the measurement calculation system of FIG. 11, an array antenna apparatus 100 as a measurement target is installed and installed on a support base 101 inside an anechoic chamber 200. A feeding port (not shown) of the feeding element A0 of the array antenna apparatus 100 is connected to the network analyzer 40 via the coaxial cable 5, and the network analyzer 40 measures the input impedance value of the array antenna apparatus 100 and is measured. The input impedance value is output to the measurement computer 50. The measurement computer 50 is constituted by a digital computer, for example, and controls the control voltage controller 30 to cause the array antenna apparatus 100 to set a desired beam pattern. As with FIG. 1, the control voltage controller 30 refers to the control voltage table memory 31 and sends a control voltage signal corresponding to the bias voltage value designated by the measurement computer 50 to each of the variable reactance elements 12-1 to 12-6. Output and set.

  The measurement computer 50 uses the control voltage controller 30 to set different sets of six control voltages in the variable reactance elements 12-1 to 12-6, and each time these control voltage sets are set, the array is set. The input impedance value of the antenna device 100 is measured and stored in the processing memory 54. Based on the measured input impedance value, the measurement computer 50 calculates a structural parameter unique to the array antenna apparatus 100 using the method described above and stores it in the processing memory 54.

As an initial setting, the user sets a reference reactance value X _m ^{(0) of} each variable reactance element 12-m (m = 1, 2,..., 6) and first and second reactance values different from the reference reactance value. Parameters including X _m ^(a) and X _m ^(b) can be set in the measurement computer 50 by connecting the initial value memory 52 storing them to the measurement computer 50. Measurements computer 50, the reactance value ^{_{X m (0), X m}} (a), reads out ^{X m (b)} from the initial value memory 52, these shift reactance values ^{_{0, Xa m (a),}} Xa m ( Convert to ^b) . Instead, the initial value memory 52 may store the reference reactance value X _m ⁽⁰⁾ and the shift reactance values Xa _m ^(a) and Xa _m ^(b) . The measurement computer 50 also outputs the structural parameter measurement results of the array antenna apparatus 100 to the CRT display 53 for display.

  FIGS. 12 to 15 are flowcharts showing the measurement calculation processing of the structural parameters of the array antenna apparatus, which is executed by the measurement computer 50 of FIG.

In step S1 of FIG. 12, the reference reactance value X _m ^{(0) of} each variable reactance element 12-m (m = 1, 2,..., 6 ⁾ and a pair of shift reactances for each variable reactance element 12-m. The values Xa _m ^(a) and Xa _m ^(b) (m = 1, 2,..., 6) are read from the initial value memory 52. In step S2, the deviation reactance values of all the variable reactance elements 12-m (m = 1, 2,..., 6) are set to 0 using the control voltage controller 30, and the network analyzer 40 is used. The input impedance value Zin ⁽⁰⁾ of the array antenna apparatus 100 at this time is measured. In step S3, a variable conversion admittance value Ya ₀₀ is calculated using Equation 9 based on the measured input impedance value Zin ⁽⁰⁾ .

In steps S4 to S7, the array antenna apparatus when the shift reactance value Xa _m ^(a) is set in one variable reactance element 12-m and the shift reactance values of the other variable reactance elements are set to 0. An input impedance value Zin _m ^{(a) of} 100 is measured. In step S4, the parameter s is initialized to 1, and in step S5, the deviation reactance value of the variable reactance element 12-s is set to Xa _s ^(a) using the control voltage controller 30, and the deviation of other variable reactance elements is set. The transactance values are set to 0, respectively, and the input impedance value Zin _s ^(a) of the array antenna apparatus 100 at this time is measured using the network analyzer 40. If it is determined in step S6 that the parameter s has reached 6, the process proceeds to step S8. Otherwise, the parameter s is incremented by 1 in step S7, and the process returns to step S5. Similarly, in steps S8 to S11, when the shift reactance value Xa _m ^(b) is set in one variable reactance element 12-m and the shift reactance values of the other variable reactance elements are set to 0. The input impedance value Zin _m ^{(b) of the} array antenna apparatus 100 is measured.

In step S12, based on the measured input impedance values Zin ⁽⁰⁾ , Zin _m ^(a) , Zin _m ^(b) (m = 1, 2,..., 6), variable conversion is performed using Expression 17 and Expression 18. The admittance values Ya _mm and Ya _0m are calculated.

In step S13 to step S19 in FIG. 13, the shift reactance value Xa _mn ^(a) is set to the two variable reactance elements 12-m and 12-n, and the shift reactance values of the other variable reactance elements are set to 0. When this is done, the input impedance value Zin _mn ^(a) of the array antenna apparatus 100 is measured. In step S13, the first parameter s is initialized to 1, and in step S14, the second parameter t is set to s + 1. In step S15, the shift reactance values of the two variable reactance elements 12-s and 12-t are set to Xa _s ^(a) and Xa _t ^(a) using the control voltage controller 30, respectively. Are respectively set to 0, and the network analyzer 40 is used to measure the input impedance value Zin _st ^(a) = Zin _ts ^(a) of the array antenna apparatus 100 at this time. If it is determined in step S16 that the parameter t has reached 6, the process proceeds to step S18. Otherwise, the parameter t is incremented by 1 in step S17, and the process returns to step S15. If it is determined in step S18 that the parameter s has reached 5, the process proceeds to step S20. Otherwise, the parameter s is incremented by 1 in step S19, and the process returns to step S14.

In step S20, the measured input impedance values Zin ⁽⁰⁾ , Zin _m ^(a) , Zin _m ^(b) , Zin _mn ^(a) (m, n = 1, 2,..., 6; m ≠ n) are set. Based on this, the variable conversion admittance value Ya _mn is calculated using Equation 19. In step S21, based on the calculated variable conversion admittance values Ya ₀₀ , Ya _0m , Ya _mm , Ya _mn , a variable conversion impedance matrix [Z a _mn ] is calculated using _Equation 11. In step S22, based on the reference reactance value X _m ⁽⁰⁾ (m = 1, 2,..., 6), the impedance matrix [Z _mn ] is calculated using Equation 5, and the admittance matrix using Equation 24. [Y _mn ] is calculated. Next, in step S23, the variable reactance element measurement process of FIG. 14 is executed. In step S24, the reactance value vs. input impedance value characteristic calculation process of the array antenna apparatus of FIG. 15 is executed, and the measurement calculation process ends.

FIG. 14 is a flowchart showing a variable reactance element measurement process (S23) which is a subroutine of FIG. Before executing the processing, the reference resistance value R _m ⁽⁰⁾ and the reference reactance value X _m ⁽⁰⁾ of each variable reactance element 12-m (m = 1, 2,..., 6) to be measured are previously determined. Set.

In step S31 of FIG. 14, the parameter s is initialized to 1, and in step S32, the control voltage V _DCs is initialized to its minimum value. In step S33, the control voltage controller 30 is used to apply the control voltage V _DCs to the variable reactance element 12-s and set a control voltage set for setting the shift reactance value of the other variable reactance elements to 0 for each variable reactance element. And the network analyzer 40 is used to measure the input impedance value Zin _s ^(p) of the array antenna device 100 at this time. In step S34, based on the measured input impedance value Zin _s ^(p) , the variable conversion impedance value Ra _s + jXa _s of the variable reactance element 12-s when the control voltage V _DCs is applied using _Equation 25 is calculated. calculate. Next, in step S35, the control voltage V _DCs is incremented by a predetermined step size. If it is determined in step S36 that the control voltage V _DCs has reached its maximum value, the process proceeds to step S37. Otherwise, the process returns to step S33. In step S37, the parameter s is incremented by 1. When it is determined in step S38 that the parameter s exceeds 6, the process proceeds to step S39. Otherwise, the process returns to step S32.

In step S39, the control voltage versus variable conversion element impedance value characteristic of each variable reactance element 12-m is obtained based on the calculated variable conversion element impedance value Ra _m + jXa _m (m = 1, 2,..., 6). In step S40, based on the reference resistance value R _m ⁽⁰⁾ and the reference reactance value X _m ⁽⁰⁾ (m = 1, 2,..., 6), the element impedance value R _m is calculated using Expression 26 and Expression 4. + after calculating the control voltage versus the element impedance value characteristic of the variable reactance element 12-m represented by jX _m, returns to the original main routine.

FIG. 15 is a flowchart showing a calculation process (S24) of reactance value versus input impedance value characteristics of the array antenna apparatus, which is a subroutine of FIG. In step S51 of FIG. 15, based on the element impedance value R _m + jX _m of each variable reactance element 12-m (m = 1, 2,..., 6), the port current i _{0 of the} power feeding element A0 is calculated using Equation 27. Calculate In step S52, based on the calculated port current i _0, after calculating the input impedance value Zin of the array antenna apparatus 100 using equation 29, the process flow returns to the main routine.

  As described above, according to the structure parameter measurement and calculation method of the array antenna apparatus according to the present embodiment, by measuring the input impedance value of the array antenna apparatus 100, each antenna element A0 of the array antenna apparatus 100 is measured. To the admittance value between A6 and A6 (or the impedance value between the antenna elements A0 to A6 which is an inverse matrix thereof) can be calculated with high accuracy.

  FIG. 16 is a block diagram showing a configuration of a structural parameter measurement calculation system of the array antenna apparatus 100 using far-field directivity measurement, which is a second example according to the first embodiment of the present invention. The measurement calculation system according to the present embodiment further includes a wireless transmitter 41, a wireless receiver 42, a horn antenna device 43, and an azimuth and elevation controller 51 in addition to the configuration of the measurement calculation system of FIG. It is characterized by that.

  In the measurement calculation system of FIG. 16, in the anechoic chamber 200, an array antenna device 100 as a transmitting antenna and a horn antenna device 41 as a receiving antenna attached to the platform of the support base 102 are mutually connected. They are set apart by a predetermined distance. The array antenna apparatus 100 transmits a radio signal from the radio transmitter 41, and this radio signal received by the horn antenna apparatus 43 is demodulated by the radio receiver 42 and measured as a far-field electric field with respect to the array antenna apparatus 100. 60. The support base 102 to which the array antenna apparatus 100 is attached is controlled by the azimuth and elevation controller 51 to rotate the array antenna apparatus 100 about the feeding element A0 as a rotation axis and stop it at a predetermined azimuth angle φ position. Furthermore, the rotation axis can be inclined by an inclination angle θ (referred to as an elevation angle in the present embodiment) from the horizontal direction (the direction of the horizontal plane of the ground conductor 11) in the direction in which the horn antenna device 41 is located. In the notation in the present specification, the inclination angle θ is omitted unless particularly necessary.

  The measurement computer 60 controls the network analyzer 40 and the wireless transmitter 41, and further switches 61 for connecting either the network analyzer 40 or the wireless transmitter 41 to the array antenna device 100 via the coaxial cable 5. To control. The measurement computer 60 sets the azimuth and elevation controller 51 to control the support base 102 so that the array antenna apparatus 100 transmits a radio signal in a desired azimuth and elevation direction, and a control voltage controller 30 is controlled to cause the array antenna apparatus 100 to set a desired beam pattern.

  Each time the measurement computer 60 changes the azimuth angle of the array antenna device 100 in the direction in which the horn antenna device 41 is located, a different set of six reactance values is changed to the variable reactance elements 12-1 to 12-6. Each time these reactance value sets are set, the electric field in the far field of the array antenna device 100 is measured using the horn antenna device 43 and the wireless receiver 42. The measurement computer 60 calculates the structural parameters specific to the array antenna apparatus 100 based on the measured far-field electric field using the method described above, and stores it in the processing memory 54.

As an initial setting, the user sets a reference reactance value X _m ^{(0) of} each variable reactance element 12-m (m = 1, 2,..., 6) and first and second reactance values different from the reference reactance value. Parameters including X _m ^(a) and X _m ^(b) can be set in the measurement computer 60 by connecting the initial value memory 52 storing them to the measurement computer 60. Measurements computer 60, the reactance value ^{_{X m (0), X m}} (a), reads out ^{X m (b)} from the initial value memory 52, these shift reactance values ^{_{0, Xa m (a),}} Xa m ( Convert to ^b) . The measurement computer 60 also outputs the measurement results of the structural parameters of the array antenna apparatus 100 to the CRT display 53 and displays them.

  FIGS. 17 to 25 are flowcharts showing the measurement calculation process of the structural parameters of the array antenna apparatus, which is executed by the measurement computer 60 of FIG.

In step S61 of FIG. 17, the reference reactance value X _m ^{(0) of} each variable reactance element 12-m (m = 1, 2,..., 6 ⁾ and a pair of shift reactances for each variable reactance element 12-m. The values Xa _m ^(a) and Xa _m ^(b) (m = 1, 2,..., 6) are read from the initial value memory 52. In step S62, the switch 61 is connected to the contact b, thereby connecting the wireless transmitter 41 to the array antenna apparatus. In step S63, the far-field electric field E ⁽⁰⁾ (φ) measurement process in FIG. 20 is executed. In step S64, the measured electric field E ⁽⁰⁾ (φ) (φ = 0, 1,... Based on this, the variable conversion equivalent steering vector element ua ₀ (φ) is calculated using Equation 36. In step S65, the far-field electric field E _m ^(a) (φ) measurement process of FIG. 21 is executed, and then in step S66, the azimuth of the array antenna apparatus 100 is measured using the azimuth and elevation controller 51 and the support base 102. The direction of the angle φ ₀ [degree] is directed to the position where the horn antenna device 43 is disposed. In step S67, the far-field electric field E _m ^(b) (φ ₀ ) measurement process of FIG. 22 is executed. In step S68, the measured electric fields E ⁽⁰⁾ (φ), E _m ^(a) (φ), Based on E _m ^(b) (φ ₀ ) (φ = 0, 1,..., 359; m = 1, 2,..., 6), using the equations 37 and 38, the variable conversion admittance value Ya _mn and The midway calculated value ua _m ^v (φ) Ya _0m is calculated. In step S69, the far-field electric field E _mn ^(a) (φ ₀ ) measurement process shown in FIG. 23 is executed. In step S70, the measured electric fields E ⁽⁰⁾ (φ), E _m ^(a) (φ), E _m ^(b) (φ ₀ ), E _mn ^(a) (φ ₀ ) (φ = 0, 1,..., 359; m, n = 1, 2,..., 6; m ≠ n) The variable conversion admittance value Ya _mn is calculated using Equation 39. Next, in step S71, the switch 61 is connected to the contact a, thereby connecting the network analyzer 40 to the array antenna apparatus 100.

In steps S72 to S77 in FIG. 18, the input impedance of the array antenna apparatus 100 is measured in order to calculate some necessary variable conversion admittance values. In step S 72, the shift reactance values of all the variable reactance elements 12-m (m = 1, 2,..., 6) are set to 0 using the control voltage controller 30, and this is performed using the network analyzer 40. The input impedance value Zin ⁽⁰⁾ of the array antenna apparatus 100 is measured. In step S73, the parameter s is initialized to 1. In step S74, the deviation reactance value of the variable reactance element 12-s is set to Xa _s ^(a) using the control voltage controller 30, and the deviation of other variable reactance elements is set. The transactance values are set to 0, respectively, and the input impedance value Zin _s ^(a) of the array antenna apparatus 100 at this time is measured using the network analyzer 40. If it is determined in step S75 that the parameter s has reached 6, the process proceeds to step S77. Otherwise, s is incremented by 1 in step 76, and the process returns to step S74. In step S77, the shift reactance value of any one of the variable reactance elements 12-k is set to Xa _k ^(b) using the control voltage controller 30, and the shift reactance values of the other variable reactance elements are set to 0, respectively. Then, using the network analyzer 40, the input impedance value Zin _k ^(b) of the array antenna apparatus 100 at this time is measured.

In step S78, the circuit impedance value Zs of the wireless transmitter 41 is calculated using _Equation 47 based on the measured input impedance values Zin ⁽⁰⁾ , Zin _k ^(a) , Zin _k ^(b) and the variable conversion admittance value Ya _kk. Calculate In step S79, the variable conversion admittance value Ya ₀₀ is calculated using Equation 16 based on the measured input impedance value Zin ⁽⁰⁾ and the calculated circuit impedance value Zs. In step S80, Equation 18 is used based on the measured input impedance value Zin _m ^(a) and the calculated circuit impedance value Zs and variable conversion admittance value Ya _mm (m = 1, 2,..., 6). Then, the variable conversion admittance value Ya _0m is calculated. In step S81, based on the midway calculated value ua _m ^v (φ) Ya _0m and the variable conversion admittance value Ya _0m (m = 1, 2,..., 6), the element ua of the variable conversion equivalent steering vector is calculated using Equation 44. Calculate _m ^v (φ) and variable transformation equivalent steering vector [ua _m ^v (φ)]. In step S82, an equivalent steering vector [u _m ⁱ (φ)] is calculated using _Equation 35 based on the variable transformation equivalent steering vector [ua _m ^v (φ)] and the variable transformation admittance matrix [Ya _mn ].

In step S83 in FIG. 19, a variable transformation impedance matrix [Za _mn ] is calculated using _Equation 11 based on the variable transformation admittance matrix [Ya _mn ]. In step S84, the impedance matrix [Z _mn ] is calculated using Equation 5 based on the reference reactance value X _m ⁽⁰⁾ (m = 1, 2,..., 6), and the admittance matrix [Y is obtained using Equation 24. _mn ]. Next, in step S85, the variable reactance element measurement process of FIG. 24 is executed. In step S86, the reactance value vs. far-field directivity calculation process of the array antenna apparatus of FIG. 25 is executed, and the measurement calculation process ends. .

FIG. 20 is a flowchart showing the far-field electric field E ⁽⁰⁾ (φ) measurement process (S63), which is a subroutine of FIG.

In step S91 of FIG. 20, the azimuth angle parameter α is initialized to 0. In step S92, the direction of the azimuth angle α [degree] of the array antenna apparatus 100 is measured using the azimuth and elevation controller 51 and the support base 102. Is directed to the position where the horn antenna device 43 is disposed. In step S93, the shift reactance values of all the variable reactance elements 12-m (m = 1, 2,..., 6) are set to 0 using the control voltage controller 30, and the radio transmitter 41 is used. A radio signal is transmitted from the array antenna apparatus 100, and the electric field E ⁽⁰⁾ (α) of the radio signal received by the horn antenna apparatus 43 is measured using the radio receiver 42. If it is determined in step S94 that the parameter α has reached 359, the process proceeds to step S64 in FIG. Otherwise, the parameter α is incremented by 1 in step S95, and the process returns to step S92.

FIG. 21 is a flowchart showing a far-field electric field E _m ^(a) (φ) measurement process (S65) which is a subroutine of FIG.

In step S101 of FIG. 21, the parameter α is initialized to 0. In step S102, the direction of the azimuth α [degree] of the array antenna apparatus 100 is changed to a horn antenna using the azimuth and elevation controller 51 and the support base 102. Turn to the position where the device 43 is located. In step S3, the parameter s indicating the parasitic element is initialized to 1, and in step S104, the shift reactance value of the variable reactance element 12-s is set to Xa _s ^(a) using the control voltage controller 30. The shift reactance values of the variable reactance elements are set to 0, wireless signals are transmitted from the array antenna device 100 using the wireless transmitter 41, and wireless signals received by the horn antenna device 43 using the wireless receiver 42 are transmitted. The electric field E _s ^(a) (α) of the signal is measured. If it is determined in step S105 that the parameter s has reached 6, the process proceeds to step S107. If not, the parameter s is incremented by 1 in step S106, and the process returns to step S104. If it is determined in step S107 that the parameter α has reached 359, the process proceeds to step S66 in FIG. 17; otherwise, the parameter α is incremented by 1 in step S108, and the process returns to step S102.

FIG. 22 is a flowchart showing the far-field electric field E _m ^(b) (φ ₀ ) measurement process (S 67), which is a subroutine of FIG.

In step S111 of FIG. 22, the parameter s is initialized to 1, and in step S112, the control reactance controller 12 is used to set the shift reactance value of the variable reactance element 12-s to Xa _s ^(b) , thereby setting another variable reactance. The deviation reactance value of each element is set to ₀ , a radio signal is transmitted from the array antenna apparatus 100 in the direction of the azimuth φ ₀ [degrees] using the radio transmitter 41, and the horn antenna is used using the radio receiver 42. The electric field E _s ^(b) (φ ₀ ) of the radio signal received by the device 43 is measured. If it is determined in step S113 that the parameter s has reached 6, the process proceeds to step S68 in FIG. 17, otherwise the parameter s is incremented by 1 in step S114, and the process returns to step S112.

FIG. 23 is a flowchart showing a far-field electric field E _mn ^(a) (φ ₀ ) measurement process (S69), which is a subroutine of FIG.

In step S121 of FIG. 23, the first parameter s is initialized to 1, and in step S122, the second parameter t is set to s + 1. In step S123, using the control voltage controller 30, the deviation reactance values of the two variable reactance elements 12-s and 12-t are set to Xa _s ^(a) and Xa _t ^(a) , respectively. Are set to 0, a radio transmitter 41 is used to transmit a radio signal from the array antenna apparatus 100 in the direction of the azimuth φ ₀ [degree], and a radio receiver 42 is used to transmit a horn antenna apparatus. The electric field E _st ^(α) (φ ₀ ) = E _ts ^(α) (φ ₀ ) of the radio signal received at 43 is measured. If it is determined in step S124 that the parameter t has reached 6, the process proceeds to step S126. If not, the parameter t is incremented by 1 in step S125, and the process returns to step S123. If it is determined in step S126 that the parameter s has reached 5, the process proceeds to step S70 in FIG. 17; otherwise, the parameter s is incremented by 1 in step S127, and the process returns to step S122.

FIG. 24 is a flowchart showing a variable reactance element measurement process (S85) which is a subroutine of FIG. Before executing the processing, the reference resistance value R _m ⁽⁰⁾ and the reference reactance value X _m ⁽⁰⁾ of each variable reactance element 12-m (m = 1, 2,..., 6) to be measured are previously determined. Set.

In step S131 of FIG. 24, the switch 61 is connected to the contact point b, thereby connecting the wireless transmitter 41 to the array antenna apparatus 100. In step S132, the parameter s is initialized to 1, and in step S133, the control voltage V _DCs is set to the minimum value. In step S134, the control voltage controller 30 is used to apply the control voltage V _DCs to one variable reactance element 12-s and set a control voltage set for setting the reactance values of the other variable reactance elements to 0 for each variable reactance element. Of the radio signal transmitted from the array antenna apparatus 100 in the direction of the azimuth angle φ ₀ [degree] using the radio transmitter 41 and received by the horn antenna apparatus 43 using the radio receiver 42. The electric field E _s ^(p) (φ ₀ ) is measured. In step S135, the variable conversion element impedance Ra _s of the variable reactance element 12-s when the control voltage V _DCs is applied using _Formula 50 based on the measured electric field E _s ^(p) (φ ₀ ). + jXa _s is calculated. In step S136, the control voltage V _DCs is incremented by a predetermined step size. If it is determined in step S137 that the control voltage V _DCs exceeds the maximum value, the process proceeds to step S138. Otherwise, the process returns to step S134. In step S138, the parameter s is incremented by 1. When it is determined in step S139 that the parameter s exceeds 6, the process proceeds to step S140, and otherwise, the process returns to step S133. In step S140, the control voltage versus impedance value characteristic of each variable reactance element 12-m is obtained based on the calculated variable conversion element impedance value Ra _m + jXa _m (m = 1, 2,..., 6). In step S141, based on the reference resistance value R _m ⁽⁰⁾ and the reference reactance value X _m ⁽⁰⁾ (m = 1, 2,..., 6), the element impedance value R _m is calculated using Expression 26 and Expression 4. + after calculating the control voltage versus the element impedance value characteristic of the variable reactance element 12-m represented by jX _m, returns to the original main routine.

  FIG. 25 is a flowchart showing a calculation process (S86) of reactance values versus far-field directivity of the array antenna apparatus, which is a subroutine of FIG.

In step S151 of FIG. 25, based on the element impedance value R _m + jX _m of each variable reactance element 12-m (m = 1, 2,..., 6), the port current vector [i _m ] is calculated using Equation 27. Calculate In step S152, based on the calculated port current vector [i _m ] and the equivalent steering vector [u _m ⁱ (φ)] (m = 1, 2,..., 6; φ = 0, 1,..., 359). After calculating the far-field electric field E (φ) using Equation 33, the process returns to the original main routine.

  As described above, according to the structure parameter measurement and calculation method of the array antenna apparatus according to the present embodiment, the equivalent steering vector of the array antenna apparatus 100 is measured by measuring the far-field directivity of the array antenna apparatus 100. Can be calculated.

  Hereinafter, simulation results using the measurement and calculation method of the electrical characteristics of the array antenna according to the first embodiment of the present invention will be described.

  First, a simulation was performed on a model of an array antenna apparatus having an asymmetric structure. FIG. 26 is a perspective view showing a configuration of an array antenna apparatus 110 according to the third embodiment of the present invention, which replaces the array antenna apparatus 100 of FIG. The array antenna device 110 is an electronically controlled waveguide array antenna device. When the wavelength of a radio signal to be transmitted / received is λ, the array antenna device 110 is a circular ground with a radius of 5λ arranged around the origin O on the xy plane in the figure. A conductor 111 is provided, and parasitic elements A11 to A16 are provided on the ground conductor 111 at a distance of 0.25λ from the origin O and at equal intervals (distance 0.25λ). On the other hand, the feed element A10 is shifted from the origin O by λ / 6 in the + x direction and the + y direction, respectively. The element length of each antenna element A10 to A16 is 0.25 wavelength, and the radius of each antenna element A10 to A16 is 0.01 wavelength. As with FIG. 1, variable reactance elements 12-1 to 12-6 (not shown) are connected to the parasitic elements A11 to A16. Therefore, in this simulation, the structural parameters of a structurally asymmetric seven-element electronically controlled waveguide array antenna device are calculated.

  FIG. 27 is a table showing reactance values set in the variable reactance elements 12-m of the array antenna apparatus 110 in the simulation related to the array antenna apparatus 110. The variable width of the variable reactance element 12-m is uniform, but is an asymmetric variable range as shown in the table of FIG. The 36 input impedances and far field directivity described above were calculated by the method of moments, and structural parameters were calculated using Equations 16 to 23, Equations 36, and 38 as measurement data. In order to see the influence of the ground conductor 111 having a finite area, the directivity in the plane with the elevation angle θ = 60 degrees was examined.

FIG. 28 is a table showing the admittance value Y _mn between the antenna elements of the array antenna apparatus 110, which is a simulation result of the array antenna apparatus 110. Since the admittance values in the table of FIG. 28 satisfy Y _mn = Y _nm , the lower left half of the table is omitted. The admittance value Y _mn was calculated using the reference reactance value X _m ⁽⁰⁾ as a known amount.

29 and 30 show simulation results for the array antenna apparatus 110, and the amplitude and phase of each element u _m ⁱ = u _m ⁱ (φ) of the equivalent steering vector of the array antenna apparatus 110 calculated by measurement. It is a graph which shows each. The thick broken line indicates the equivalent steering vector elements u ₁ ⁱ ,..., U ₆ ⁱ measured and calculated in this simulation, and the thin solid line indicates the equivalent steering vector element u ₁ ⁱ , calculated using the direct moment method. ..., u ₆ ⁱ . Each agrees well. In addition, asymmetry is reflected in the admittance value Y _mn of FIG. As described above, the effectiveness of the measurement and calculation method of the present embodiment can be confirmed.

  Next, simulation results using the array antenna apparatus 100 of FIG. 1 will be described. The characteristics of the entire antenna housing are reflected in the admittance matrix and the equivalent steering vector. The structural parameter is calculated by actual measurement. Measurement was performed at a design frequency of 2.484 GHz.

First, the dependence of the element impedance value of the single variable reactance element on the control voltage _VDC was examined. FIG. 31 is a graph showing the element impedance value Z characteristic with respect to the control voltage _VDC in the single variable reactance element used in the array antenna apparatus 100. A variable reactance element of the same type as that loaded on the array antenna apparatus 100 of the first embodiment (in this embodiment, a 1SV287 varactor diode manufactured by Toshiba is used) is attached to the tip of the SMA connector, and the control voltage _VDC is changed. The element impedance value was measured with a network analyzer. Calibration at the tip of the SMA connector was performed, and the impedance value of the single variable reactance element was calculated. The calculation result is shown in FIG. Although the variable reactance element is a capacitor, it can be seen that the reactance value is positive when the control voltage V _DC is zero. The reaction width of the reactance value is the same as the catalog value, but the range is shifted in the positive direction as a whole, and this shift increases as the frequency increases. From the frequency dependence, it was found that there was an electric inductivity of about 1.5 nH. The existence of this electric dielectric property is considered to be caused by a lead wire inside the variable reactance element.

The curve in FIG. 31 can be expressed by a sixth-order function of the control voltage _VDC expressed by the following equation, and this function well represents the reactance value characteristic of the variable reactance element.

Further, the resistance R, which is a real component, can be well expressed by a linear function of the control voltage V _DC expressed by the following equation.

When the reference element impedance value R _m ⁽⁰⁾ + jX _m ⁽⁰⁾ , which is the reference of the element impedance value of the variable reactance element 12-m, varies, as described above, the variation loads the variable reactance element. The impedance matrix [Z _mn ] of the array antenna apparatus is transferred. The control voltage V _DC corresponding to the reference reactance value X ⁽⁰⁾ is set to −0.5 [V] at which the reactance value is maximized. That is, the reference element impedance value R ⁽⁰⁾ + jX ⁽⁰⁾ of each variable reactance element is 0.762 + 14.04 j (Ω). Further, the control voltage V _DC of the reactance value X ^(a) is set to 20 [V] at which the reactance value is minimized. Since the control voltage V _DC and the element impedance value satisfies an approximately linear relationship, as a control voltage V _DC reactance value X ^(b), at the intersection I1 of the characteristic curve of the straight line and the number 51 for connecting two points of both ends A voltage value of 7.4 [V] was selected.

Next, the structural parameter calculation of the array antenna apparatus 100 will be described. FIG. 32 is a table showing simulation results according to the first embodiment of the present invention and admittance values Y _mn between the antenna elements of the array antenna apparatus 100 calculated by measurement. Since the admittance values in the table of FIG. 32 satisfy Y _mn = Y _nm , the lower left half of the table is omitted. In the table of FIG. 32, 36 data are measured and the admittance value Y _mn obtained by calculation is shown in the same manner as the simulation of the array antenna apparatus 110 described above. 33 and 34 show simulation results according to the first embodiment of the present invention, and each element u _m ⁱ = u _m ⁱ (φ of the equivalent steering vector of the array antenna apparatus 100 calculated by measurement is calculated. ) Is a graph showing the amplitude and phase. The amplitude | E | on the vertical axis in FIG. 33 is the value of the electric field at the measurement point (that is, the position where the horn antenna device 43 is disposed) including the output level information of the transmitter. Asymmetry is also observed in the admittance value Y _mn , but is more prominent in each element u _m ⁱ (φ) of the equivalent steering vector. Since the asymmetry of each element u _m ⁱ (φ) of the equivalent steering vector is more conspicuous than the simulation result for the array antenna apparatus 110 in FIG. 26, the variable is being mounted on the casing of the array antenna apparatus 100 or loaded. This is considered to be an influence of the reactance element 12-m. Note that the phase pattern of each element u _m ⁱ (φ) of the equivalent steering vector varies depending on the method (that is, the center position of the rotation axis) of placing the array antenna apparatus 100 on the support base 102 that rotates during measurement.

Next, the control voltage characteristics of the mounted variable reactance element 12-m will be described. FIG. 35 is a simulation result according to the first embodiment of the present invention, and shows an impedance value Z characteristic of the variable reactance element 12-3 loaded on the parasitic element A3 of the array antenna apparatus 100 with respect to the control voltage V _DC3. It is a graph which shows. In this simulation, calculation is performed according to Equation 25, Equation 26, and Equation 4 from the input impedance value Zin measured while changing the control voltage V _DC3 applied to the variable reactance element 12-3 loaded on the parasitic element A3. The element impedance value Z ₃ = R ₃ + jX ₃ of the variable reactance element is indicated by a circle in the graph of FIG. 35, thereby expressing the control voltage dependence of the element impedance value Z ₃ . Since each parasitic element of the monopole of the prototype array antenna apparatus 100 is loaded with two variable reactance elements in parallel, a doubled value is shown for conversion into one. Note that the reference element impedance value R _m ⁽⁰⁾ + jX _m ⁽⁰⁾ = 0.762 + 14.04j. The lines in the figure are Equations 51 and 52, but the circles indicating the measurement results are on the curve very well and agree well with the results of the single measurement in FIG.

Finally, the calculated value related to the structural parameter of the array antenna apparatus 100 is compared with the actually measured value. FIG. 36 shows a set of control voltages V _{DC1 to} V _DC6 respectively set in the variable reactance elements 12-1 to 12-6 of the array antenna apparatus 100 of FIG. 1 in the simulation according to the first embodiment of the present invention. FIG. 37 is a table showing the input impedance value Zin of the array antenna apparatus 100 when the control voltage sets of cases 1 to 3 in FIG. 36 are set. Using the calculated structural parameters, the input impedance for the reactance value set as shown in the table of FIG. 36 is calculated using Equations 14 and 15, and the directivity in the plane of elevation θ = 90 degrees is calculated using Equation 33. did. The result of the input impedance value is shown in the table of FIG. It is in good agreement with the measured input impedance value. From this, it can be seen that an appropriate admittance value Y _mn is calculated.

  38 and 39 are simulation results according to the first embodiment of the present invention, and the directivity pattern of the gain and phase when the control voltage set of case 1 of FIG. 36 is set in the array antenna apparatus 100. FIG. 40 and 41 are graphs showing the directivity patterns of the gain and the phase when the control voltage set of case 2 in FIG. 36 is set in the array antenna apparatus 100, respectively. FIG. 43 and FIG. 43 are graphs respectively showing the directivity patterns of gain and phase when the control voltage set of case 3 of FIG. 36 is set in the array antenna apparatus 100. The vertical axis | shaft of the graph which shows the gain of FIG.38, FIG.40 and FIG.42 shows with the value of measurement raw data. The actual measurement value is indicated by a thin solid line, and the calculation result by the equivalent steering vector model of the present embodiment is indicated by a fine broken line. Both agree well, and it can be seen that the correct equivalent steering vector can be calculated. The calculation result by the method of Non-Patent Document 3 assuming symmetry is shown by a rough broken line. This calculation result is partly different from the actual measurement value, and the improvement by the method according to the first embodiment of the present invention is large. I understand. Although the result of the equivalent weight vector model is indicated by a one-dot chain line, it can be seen that the correct directivity is not calculated. Since the input impedance value closely matches the experimental result, the calculated admittance value is considered to be correct.

Further, since the admittance value Y _{mn in} the table of FIG. 32 is greatly different from the moment method calculation result, it is considered that the admittance value related to the port close to the variable reactance element 12-m is calculated. When the line length between the variable reactance element 12-m and the parasitic element Am cannot be ignored, the current at a position close to the variable reactance element 12-m deviates from the current flowing through the parasitic element Am. This is not a problem with the equivalent steering vector model, but is a problem because the equivalent weight vector model thinks that port current is radiated into space. That is, as schematically shown in FIGS. 6 to 8, the positions assumed as ports in the two models are different. Therefore, the value of admittance between ports is also different.

  As described above, based on the equivalent steering vector model, the structural parameters (admittance matrix and equivalent steering vector) of the electronically controlled waveguide array antenna device are measured M + 2 times, and (M + 1) (M + 2) / 2 times. A method for obtaining the impedance by measuring the input impedance value is shown, and the structural parameters of the prototype electronically controlled waveguide array antenna device are calculated for the first time. Thereby, it is possible to calculate the antenna characteristics when an arbitrary reactance value is set. Also, the control voltage dependence of the element impedance of the variable reactance element in the loaded state can be calculated. However, in this method, it is assumed that the amount by which the reactance value is changed from the reference value in the two control voltages applied to each parasitic element is known. If structural parameters can be obtained by measurement, complicated work such as dimensioning becomes unnecessary, and any reactance value can be obtained by measuring antenna characteristics once several reactance value sets are set for each variable reactance element. The antenna characteristics when the set is set to a variable reactance element can be calculated.

<Second Embodiment>
Next, a method for calculating and measuring the electrical characteristics of the array antenna according to the second embodiment of the present invention will be described below. The present inventors calculated the structural parameters (impedance matrix and equivalent steering vector) of the electronically controlled waveguide array antenna device calculated by the input impedance measurement and the far field directivity measurement as a value of the variable reactance element at the time of measurement. For each variable reactance element 12 to be assigned to, it varies depending on three reactance values, but the input impedance and directivity in any control state and the output impedance of the feeder circuit are found to be constant regardless of the calculated parameter value did. In the second embodiment, the cause and the degree of freedom of the reactance value will be examined, and the reduction of the number of measurement of structural parameter extraction and the simplification of the calculation using this option will be described.

  As described above, the electronically controlled waveguide array antenna device includes one feed element A0 and at least one parasitic element (such as A1-A6), and the variable reactance element 12 loaded on the parasitic element A0. The directivity can be changed by controlling the variable reactance value (see Non-Patent Document 5). The dependence of directivity and input impedance on reactance values can be expressed by an equivalent steering vector model (see Non-Patent Document 3). The admittance matrix and equivalent steering vector used in this model are structural parameters that do not depend on reactance values. The structural parameter can be calculated by an analysis method such as the moment method, the finite element method, or the ICT method, but is difficult to calculate including the influence of the antenna housing. If measurement is used, it is possible to extract structural parameters including the influence of manufacturing errors. On the other hand, the variable reactance value is an amount that changes by control, but the exact control characteristic (dependence of reactance value on DC voltage) is not known. The actual variable reactance value has individual differences between elements, and measurement is necessary to take into account individual differences. If the structural parameters are extracted and the control characteristics of the variable reactance element are calibrated, the actual antenna characteristics in an arbitrary control state can be obtained by calculation. This makes it possible to simulate on the computer the directivity variable capability of the electronically controlled waveguide array antenna device and the directivity control suitable for the radio wave environment.

In the present embodiment, as a method for obtaining the structural parameter and the variable reactance value by measurement, a method using input impedance or far-field directivity measurement (see Non-Patent Documents 4 and 6) is proposed below (hereinafter, referred to as “non-patent documents 4 and 6”). I ² F ² (Input Impedance and Far Field) method). In the above-described second embodiment and Non-Patent Document 6, for example, the reactance values in the three control states are known for each variable reactance element, the structure parameter is calculated based on the value, and the structure parameter is further determined. In addition, it was shown that the variable reactance value in any control state can be calculated. However, how to obtain three standard reactance values remains as a problem. In the present embodiment, the I ² F ² method is studied for the purpose of solving this problem.

First, the relationship between the structural parameter, the variable amount, and the measured amount will be described below. Structural parameters and reactance values are calculated from measured quantities. Therefore, the relationship between these physical quantities is organized below. In the electronically controlled waveguide array antenna device, the connection part (feed point) where the feed circuit is connected to the feed element A0 and the connection part where the variable reactance element 12 is loaded to the parasitic element (A1-A6 etc.) are ported. (It is uncertain how far the connection part is viewed. Each port is electrically insulated from the ground conductor 11). In the present embodiment, m-th element (the number of parasitic elements is M, the feed element and m = 0) the current flowing in the port portion of the i _m. Port current i _m of the parasitic element is excited by the mutual coupling between ports. The coupling is represented by a mutual impedance _Zmn between the mth port and the nth port. Also, the parasitic element so variable reactance element 12 is loaded, self-impedance can be expressed as the sum of the impedance jX _m impedance Z _mm and the variable reactance element 12. This is called “varactor retraction self-impedance” (see Non-Patent Document 5). Here, X _m is a variable reactance values loaded to m-th passive element port. In summary, the port current i _m is indirectly controlled It can be seen by the variable reactance value X _m by the following equation (Non-Patent Document 5 reference.). In addition, in the following description, the number number of the black brackets in which the mathematical formula is input and the mathematical formula number in square brackets in which the mathematical formula is input are used in combination, and a series in the specification is used. The formula number is assigned to the last part of the formula using the format of “formula (1)” (there is also a formula that is not given).

[Equation 1]
[I _m ] = ([Z _mn ] + [X _m ]) ⁻¹ [vs _n ] (1)
[Equation 2]
[X _m ] ≡diag [Zs, jX ₁ , jX ₂ ,..., JX _M ]
[Equation 3]
_{[Vs n] = [v s} , 0,0, ..., 0] T

  Vs is an open circuit voltage of the power feeding circuit, and Zs is an internal impedance of the power feeding circuit. Superscript T represents transposition of the matrix. The input impedance is expressed by the following equation depending on the power feeding port current.

[Equation 4]
Zin = (vs / i ₀ ) −Zs (2)

On the other hand, by the product of the directivity (i.e., far-field electric field) E (phi, theta) vector the port current _{i m} and element _{[i m]} equivalent steering vector ^{_{[u m i (φ, θ}} )], It is represented by the following formula (see Non-Patent Documents 5 and 6).

[Equation 5]
E (θ, φ) = [u _m ⁱ (θ, φ)] ^T [i _m ] (3)

The element u _m ⁱ (θ, φ) of the equivalent steering vector is directivity when a unit current flows only through the port m, and the voltage generated at the port n is the impedance Z _mn . Similarly, the admittance Y _mn is defined as a current flowing through the port n when a unit voltage is generated only in the port m, and the directivity that is a far-field electric field is defined as u _m ^v (θ, φ). The admittance matrix [Y _mn ] is an inverse matrix of the impedance matrix [Z _mn ]. When [u _m ^v (θ, φ)] is an equivalent steering vector, the directivity E (φ, θ) can be expressed using the port voltage v _m as a weight (weighting coefficient) (Non-Patent Documents 4 and 6). reference.).

[Equation 6]
E (θ, φ) = [u _m ^v (θ, φ)] ^T [v _m ] (4)

Each parameter Z _mn , u _m ⁱ (θ, φ) and Y _mn , u _m ^v (θ, φ) can be directly measured by opening or short-circuiting only each port according to their definition. . However, in the electronically controlled waveguide array antenna device, since the variable reactance element 12 is loaded on the port by soldering or the like, processing is required to open or short-circuit the port.

On the other hand, if the variable reactance element 12 is removed and measured, the applied voltage versus capacity characteristic of the variable reactance element 12 including individual differences (product variations) can be obtained. However, the characteristics of the mounting state are affected by soldering, lead wires, etc., and the influence is not constant (mounting variation). It is necessary to measure the characteristics including variations in mounting in the mounted state. Therefore, measurement is performed in the control state of several variable reactance elements while the variable reactance elements are loaded, and a structural parameter and a variable reactance value are calculated from the measured values.

The relationship between the structural parameters, reactance values, and measured quantities is shown in FIG. The impedance Z _mn , which is a structural parameter, the equivalent steering vector u _m ⁱ (θ, φ), and the circuit impedance Zs of the feeder circuit are fixed parameters. On the other hand, the reactance value is a variable amount, and the value of the measured amount varies depending on this value. Both structural parameters and variable reactance values are unknown. If the port current i _m and the measured amount from the relation of equation (1) can be determined structural parameters Z _mn and the reactance value X _m (Non-Patent Document 7 reference.). However, a current probe is required to measure current. In the I ² F ² method, it is possible to measure the input impedance Zin and the directivity E (φ, θ) of the far field using a more general-purpose measuring device.

Next, the optionality regarding self-impedance will be described below. In the following, the arbitraryness that appears when the variable reactance value is an unknown number together with the admittance matrix will be described. The antenna characteristic is expressed by the port current [i _m ], but the equation [1] determines the [i _m ] from the equation [1] to the following matrix [E _mn ]:
[Equation 7]
[E _mn ] = [Z _mn ] + [X _m ]
It can be seen that the impedance matrix [Z _mn ] and the variable reactance matrix [X _m ] are not determined. Since the matrix [X _m ] is a diagonal matrix, the sum of the diagonal components Z _mm and jX _m is determined, but the way of dividing them is arbitrary. In order to express the arbitraryness, the reactance value in a certain control state (0) is represented by X _m ⁽⁰⁾ . A special solution satisfying equation (5) is represented by a parameter with “a”.

[Equation 8]
Xa _m ⁽⁰⁾ = 0 (5)

If set as described above, an arbitrary impedance Z _mm and reactance X _m expressed by the following equations are also solutions to the equation (1).

[Equation 9]
^{_{X m = Xa m + X m}} (0) (6)
[Equation 10]
Z _mm = Za _mm -jX _m ⁽⁰⁾

Here, the reactance X _m ⁽⁰⁾ is not an unknown but an arbitrary parameter. That is, the unknowns are reduced by the number M of parasitic elements. Equation for the parameter with "a" (1), (3), defining the port voltage va _m dated tilde as follows, can be expressed and organize.

[Equation 11]
[I _m ] = ([Z a _mn ] + [X a _m ]) ⁻¹ [vs _n ]
[Equation 12]
_{[Za mn] [i m]} = [vs n] - [Xa m] [i m] = [va n] (7)
[Equation 13]
[Va _n ] = [vs, −jXa ₁ i ₁ , −jXa ₂ i ₂ ,..., −jXa _M i _M ] ^T
[Formula 14]
E (θ, φ) = [ua _m ^v (θ, φ)] [va _m ] (8)
[Equation 15]
[Ua _m ^v (θ, φ)] = [u _m ⁱ (θ, φ)] [Ya _mn ]

Incidentally, the port current _{i m} is intact. In the parameter with “a”, since Xa _m (0) = 0 in the state (0), it can be considered that va _m = 0, that is, a short-circuit state. As a result, the parameters relating to the short-circuited element can be erased, and the calculations of equations (7) and (8) are simplified.

Next, evaluation of the number of measurements will be described below. In order to solve the unknown, it is necessary to obtain a larger amount of measurement. Below, the relationship between the number of unknowns and the number of measured quantities is described. When the number of parasitic elements is M, the number of impedances Z _mn or admittances Y _mn is {(M + 1) (M + 2) / 2}. There are (M + 1) elements u _m ⁱ (θ, φ) or u _m ^v (θ, φ) of the equivalent steering vector. Furthermore, since the internal impedance Zs of the transceiver is a fixed unknown, there are {(M + 2) (M + 3) / 2} structural parameters in total. Note that the number of unknowns is the same even if the parameters with “a” are considered. If the reactance value is known, all structural parameters can be calculated by increasing the measurement to the required number of times. For example, in the first embodiment and Non-Patent Document 6, by making the reactance values X _m ^(a) and X _m ^(b) in two states other than X _m ^{(0) known} for each parasitic element, It was shown that all structural parameters can be extracted by performing the input impedance measurement and the far field directivity measurement together {(M + 2) (M + 3) / 2} times.

On the other hand, if the reactance values of all the variable reactance elements 12 are not known, an attempt to increase the amount of measurement will increase the number of reactance values set at the time of measurement, thus increasing the number of unknowns. In the current measurement, a current of M + 1 elements can be measured in a certain reactance value set state. On the other hand, in the I ² F ² method, only two of input impedance and far-field directivity can be measured. The input impedance Zin is expressed by equation (2). Further, the power feeding port current i ₀ in the formula (2) is expressed by the following formula.

[Equation 16]
i ₀ = [Ya _0m ] [va _m ] (9)

Comparing the equations (3) and (9), the dependency on the port voltage va _m is equal, and the reactance value X _m is included only in the port voltage va _m. Therefore, the input impedance Zin and the far electric field E (φ, θ ) is not independent with respect to the reactance X _m dependence. Thus, from the standpoint of solving the reactance value X _m unknowns, measured quantity is considered to only one. Incidentally, the electric far field E (φ, θ) has a directional dependence is independent of the direction dependence and reactance X _m dependence. Since the measurement amount is only one, increasing one unknown reactance value X _m, measured quantities only be one obtained. However, as the equation (7) or the equation (9), the measurement amount is a function of the reactance value of M parasitic elements, so that a plurality of measurement amounts can be obtained by combining the reactance values. When the number of unknown reactance values other than X _m ⁽⁰⁾ is N for each parasitic element, the number of unknowns of variable reactance elements is NM, and the number of measurable measurable quantities is (N + 1) ^M. . FIG. 45 shows the relationship between the number of unknowns and the number of measured quantities when _obtaining {(M + 1) (M + 2) / 2} admittances Z _mn in the measurement of input impedance.

In the current measurement method, even if the number of unknown reactance values N = 1 for each parasitic element, it is possible to obtain a larger amount of measurement than the unknown in any case. On the other hand, in the I ² F ² method, the number M of parasitic elements is 4 or more in order to obtain a measurement amount larger than the unknown when N = 1. However, in the I ² F ² method, the relationship between the current and the unknown is more complicated than that in the current measurement method, so that the calculation becomes difficult when the number M of unknowns included in one equation is large. Therefore, the measurement is limited to a case where the number of parasitic elements having reactance values not satisfying Expression (6) is two or less. The number of measurement weight ^{{M (M-1) N} 2/2 + NM + 1} number and will, as shown in FIG. 45, in the case of M = 6 is if N = 2, to obtain many measured quantities from unknowns Can do.

Next, the optionality will be described below. In the above description, a method for obtaining a measurement quantity larger than the unknown quantity is described. However, the unknown quantity cannot be solved unless the measurement quantity is independent. In the following, this point will be examined. To summarize the results of the first embodiment and Non-Patent Document 6, the mutual admittance Ya _mn of admittance with “a” is calculated from the measured value of the input impedance Zin as follows.

Here, Zin _mn ^(pq) is the reactance value of the _mth parasitic element 12 is Xa _m ^(p) , the reactance value of the _nth parasitic element 12 is Xan ^(q) , and the remaining parasitic elements This is the input impedance when the reactance value of 12 is Xa _k ⁽⁰⁾ . The product of the reactance value than the formula (10) _Xa ^{m (a)} is contained only in the parameter _Q ^{m (a),} Equation (10) from the admittance _{Ya mn} parameter _Q ^{m (a)} a parameter _Q ^{n (a)} It can be seen that Therefore, the effect of changing the reactance Xa _m ^(a) of the _mth parasitic element 12 does not depend on the reactance value Xa _n ^(a) of the _nth parasitic element 12. Therefore, even if the reactance value Xa _n ^(a) is changed and the input impedance Zin _mn ^(pq) is measured with several reactance values Xa _m ^(a) , the number of the reactance values Xa _n ^(a) is independent. Measurement results cannot be obtained. That is, the input impedance measurement value based on the combination of reactance values as described above is not independent. In other words, the parameter Q _m ^(a) can be any value other than zero. Furthermore, the parameter Ya _mn and the reactance value Xa _m ^(a) can be selected to be arbitrary values from the equation (11).

Next, the cause of the optionality will be described below. The reason why the admittance Ya _mn and the reactance value Xa _m ^(a) are arbitrary will be discussed below. The current measurement method measures the current at each port, but the I ² F ² method does not. Further, in the equivalent steering vector model that is the basis of this measurement method, the position may be arbitrary as long as the port is fixed. Therefore, the port position is indefinite. If the port position changes, the reactance value Xa _m ^(a) and the impedance Za _mn change (see the first embodiment and Non-Patent Document 6). Due to this indefiniteness, the reactance value Xa _m ^(a) and the impedance Za _mn have one degree of freedom. It can be considered that the admittance Ya _mn is free instead of the impedance Za _mn . In order for the admittance Ya _mn and the reactance value Xa _m ^(a) to be arbitrary, another degree of freedom is required. The degree of freedom can be explained by the following indefiniteness allowed because the port current of the parasitic element is not measured in the I ² F ² method.

When the following equation (11) holds, the equation (12) obtained by multiplying the reactance value of each parasitic element Am by an arbitrary constant α _m also holds.

In the equations (12) and (13), the feed element port current i ₀ is kept constant even if the port current of the parasitic element changes. As can be seen from equation (2), the input impedance Zin is determined only by the port current i _{0 of the} feed element, so that the current i _{0 of the} feed element is If it is correct, the input impedance is not affected. As for the equivalent steering vector _ua ^{m v} (phi), value that is extracted by the far field measurements, as of the formulas described below (17), so the product of the admittance _{Ya 0 m,} admittance _{Ya 0 m} is a constant multiple In this case, if the equivalent steering vector ua _m ^v (φ) is a reciprocal multiple thereof, the far electric field is not affected. Therefore, even if each parameter changes by a constant multiple as shown in FIG. 46, the same input impedance far-field measurement can be obtained.

Next, selection of an arbitrary parameter will be described below. It has been found that the reactance value X _m ⁽⁰⁾ , the admittance Ya _mn , and the reactance value X ^a _m ^(a) are arbitrary. However, as an optional parameter, instead of the admittance Ya _mn and the reactance value X ^a _m ^(a) , reactance value _Xa ^{m (a)} and reactance values _Xa ^{m (b)} or admittance _{Ya 0 m} and reactance values ^{Xa m (a)} and reactance values _Xa ^{m (a)} or it is also possible to choose the admittance _{Ya mn} and admittance _{Ya 0 m} It is. In the first embodiment and Non-Patent Document 6, the values of the reactance value X _m ⁽⁰⁾ , the reactance value Xa _m ^(a) , and the reactance value Xa _m ^(b) are given as known amounts. I understand that it's okay. That is, even if values different from the actual values are used as the reactance value X _m ⁽⁰⁾ , the reactance value Xa _m ^(a) , and the reactance value Xa _m ^(b) , the error is arbitrarily absorbed. Formulas for calculating the admittance matrix from the arbitrary parameters and the measured values are summarized in FIG. In addition, only the mth parasitic element is set to an arbitrary state (p) and the reactance value of the other parasitic element is set to Xa _k ^(0), and the measured input impedance value is changed from Zin _m ^(p) to the variable reactance. An equation for calculating the value of the element 12 is also shown in FIG. P _m ^(p) in the table is defined by the following equation.

As shown in the above equation, the actual variable reactance element also has a resistance component, and its value is also calculated. To account for the resistance component in the foregoing calculation formula, the impedance jX _m in the formula to _R m + jX _m, may be changed impedance jXa _m in _{Ra m} + jXa m. FIG. 47 also shows the number of unknown structural parameters and the number of measurements necessary to obtain them. Admittance _{Ya mm} and admittance _{Ya 0 m} or by choosing admittance _{Ya mm} and reactance values _Xa ^{m (a),} the admittance _{Ya 0 m} and admittance _Xa ^{m (a)} as an optional parameter, the reactance values _Xa ^{m (a)} and reactance values Xa Compared to the case where _m ^(b) is an arbitrary parameter, the number of measurements can be reduced M times. When the admittance Ya _mm and the admittance Ya _0m are used as optional parameters, the number of unknown admittances is reduced by M compared to the other two, but the input impedance Zin _m ^(a) needs to be measured. It only decreases. When admittance Ya _mm or admittance Ya _0m is used as an arbitrary parameter, it is convenient to select a value that is easy to calculate because it always appears in the calculation formula. However, 0 is not allowed as the admittance Ya _mm and the admittance Ya _0m , and the reactance value X _m ⁽⁰⁾ , the reactance value Xa _m ^(a), and the reactance value Xa _m ^(b) are equal to each other. It is necessary to avoid setting to. It can be seen from FIG. 47 that the admittance Ya _mn depends only on the admittance Ya _0m and does not depend on the admittance Ya _mm . 47 includes the impedance Zs of the power feeding circuit, but the calculation result of the admittance without “a” does not depend on the input impedance Zs of the power feeding circuit. This is because the admittance of the antenna device does not depend on the power feeding circuit.

As a formula for calculating the structural parameter and the reactance value from the far field, the case where the reactance value Xa _m ^(a) and the reactance value Xa _m ^(b) are arbitrary parameters is described (see the first embodiment and Non-Patent Document 6). ).

[Equation 17]
^{_{Q 5 = Ya 0m ua n v}} (φ 0) + Ya 0n ua m v (φ 0)
[Equation 18]
Q ₆ = 2 (E _mn ^(aa) (φ ₀ ) −E ⁽⁰⁾ (φ ₀ )) / vs
[Equation 19]
Q ₇ = Q ₅ ² -Q ₆ Q ₈
[Equation 20]
Q ₈
= Q _m ^(a) Q _n ^(a) Q ₆
+ 2jYa _{0 m} ua _m ^v (φ ₀ ) Q _n ^{(a)
_{+ 2jYa 0n ua n v (φ}} 0) Q m (a) (19)

Since the admittance Ya _0m and the equivalent steering vector ua _m ^v (φ) are obtained from the far electric field as shown in the equation (16), the input impedance measurement is added M + 1 times to obtain the admittance Ya ₀₀ and the admittance Ya _0m. There is a need to. Conversely, in the measurement of the input impedance in FIG. 47, if (M + 1) far field measurements of the far field E ⁽⁰⁾ (φ) and the far field E _m ^(a) (φ) are added, the equation (15) ) And equation (17), all equivalent steering vectors ua _m ^v can be obtained. Although the input impedance and the directivity pattern shape do not depend on the impedance Zs of the power feeding circuit, the impedance Zs needs to be extracted because it affects the gain change due to the matching loss. For this purpose, the input impedance Zin _m ^(b) and the far electric field E _m ^(b) (φ ₀ ) when the state (b) is set for one parasitic element Am are measured and calculated by the following equation.

From equation (18), it can be seen that the impedance Zs of the power feeding circuit does not depend on the reactance value Xa _m ^{(a), the} reactance value Xa _m ^(b), or the admittance value, but is determined only by the measured value (see supplementary explanation below). .). Since the impedance Zs of the feeder circuit is a physical quantity that can actually be observed as a matching loss, the result is consistent with the fact that it is not allowed to be influenced by an arbitrary parameter.

Furthermore, numerical calculation and the calculation result will be described below. In order to evaluate a general electronically controlled waveguide array antenna device, as shown in FIG. 48, the feed element A0 is shifted by λ / 6 in the x-axis and y-axis directions from the coordinate center of the xyz coordinate system, and the radius is a half wavelength. The structural parameters of a structurally asymmetric seven-element electronically controlled waveguide array antenna apparatus having a circular ground conductor 11 are extracted. The array circle radius of each element length A0-A6 and the parasitic elements A1-A6 centering on the feed element A0 is 0.25 wavelength, and the radius of each element A0-A6 is 0.01 wavelength. Further, non-uniform values as shown in FIG. 49 are given as reactance values X _m ⁽⁰⁾ , X _m ^(a) , and X _m ^{(b) to} be measured. As shown in FIG. 50, m calculated when reactance values X ₁ ^(a) and X ₁ ^(b) or reactance values X ₂ ^(a) and X ₂ ^(b) are given values different from the actual values. FIG. 51 shows the impedance of the variable reactance element 12 of the first element. The horizontal axis shows the actual reactance value instead of the control parameter. Case 5 also shows the result calculated by giving admittance Ya _mm = Ya _0m = 0.001 as the reactance value of the variable reactance element 12 loaded on all the parasitic elements. It can be seen that by selecting the reactance values Xa _m ^(a) and Xa _m ^(b) , a value different from the correct value of the variable reactance value is calculated, and the control characteristics change. An incorrect value is also calculated for the admittance value. Even if the reactance value of the variable reactance element 12 loaded on the parasitic element A2 is set to an incorrect value from the result of the case 4, the reactance value of the reactance element 12 loaded on the parasitic element A1 is the correct value. It can be seen that is calculated. In addition, as in case 3, the reactance value Xa _m ^(b) , which should be in the magnitude between the reactance value Xa _m ⁽⁰⁾ and the reactance value Xa _m ^(a) , is not within the range. Shows that the reactance value diverges. When the impedance of the variable reactance element 12 changes continuously with respect to the control parameter, the measurement points for obtaining the control characteristics can be reduced by using interpolation. Interpolation with is difficult. Further, when the admittance Ya _mm = Ya _0m = 0.001, it can be seen that the resistance component of the variable reactance element 12 is calculated as a non-zero value. Using these different parameter values, the antenna characteristics of the reactance value set as shown in FIG. 49 were calculated. FIG. 53 shows the input impedance calculation result, and FIG. 54 shows the directivity. In order to examine the influence of the ground conductor 11 which is a finite ground plane, in-plane directivity with an elevation angle θ = 60 degrees is shown. As is apparent from FIGS. 53 and 54, both characteristics agree well with the correct values calculated by the moment method. In the directivity graph, the dots representing the results of each case overlap and are on the curve of the moment method calculation results. Thereby, although the calculated structural parameter and reactance value are different from the true values, it can be confirmed that correct antenna characteristics are calculated.

As described above, according to the present embodiment, it was found that the extracted structural parameter and the calibrated variable reactance element value are arbitrary by the input impedance measurement and the far field measurement. There are three options for each element, and the parameter calculated by the value varies, but the input impedance and far field directivity calculated from the parameter and the internal impedance Zs of the transceiver are constant and correct values. Is calculated. One of the three degrees of freedom is based on the property that the antenna characteristics depend on the sum of the reactance value and the self-impedance, and the allocation is arbitrary. One degree of freedom is considered to be that the position is arbitrary as long as the port is fixed in the equivalent steering vector model, and it is undefined even in actual measurement. The remaining degrees of freedom are considered to be because the current flowing through the parasitic element is not measured and indefiniteness is allowed for the measured quantity. Due to this degree of freedom, the self-admittance Ya _mm or the mutual admittance Ya _0m between the feeding elements can be set as an arbitrary parameter. As a result, the number of measurements required to calculate the structure parameter can be reduced M times compared to the case where the reactance value is an arbitrary parameter. Further, the calculation can be easily performed by selecting an appropriate value as the admittance value.

<Various aspects of the present invention>
Several aspects of the present invention based on the above first and second embodiments will be described below.

According to the method for measuring the structural parameter of the array antenna according to the first aspect of the present invention for determining the structural parameter (specifically, inter-port admittance or impedance),
A feed element for transmitting and receiving a radio signal, at least one parasitic element provided at a predetermined interval from the feed element, and a variable connected between the feed element and the parasitic element And reacting each parasitic element as a director or a reflector by setting a control voltage to each variable reactance element and changing a reactance value of each variable reactance element. The directivity of the array antenna is changed.
Limiting the control voltage set to each of the variable reactance elements to some, and measuring the input impedance in some control states of combinations between the parasitic elements of the control voltage;
The relationship between the admittance value or impedance value between each antenna element port, the impedance value of the variable reactance element viewed from the port of each parasitic element, and the input impedance, the input impedance measurement value, and the above several control voltage settings Substituting the impedance value of the variable reactance element viewed from the port of each parasitic element in the state to calculate the admittance value or impedance value between the antenna element ports.

According to the array antenna structural parameter measurement method for obtaining a structural parameter (specifically, an equivalent steering vector) according to the second aspect of the present invention, a feed element for transmitting and receiving a radio signal, and the feed element At least one parasitic element provided at a predetermined interval, and a variable reactance element connected between the feeder element and the parasitic element, and each of the variable reactance elements has a control voltage. By changing the reactance value of each of the variable reactance elements and changing the directivity of each parasitic element to operate as a director or a reflector, for example, an electronically controlled waveguide array antenna A method for measuring the electrical characteristics of an array antenna as a device,
Limiting the control voltage set to each of the variable reactance elements to some, and measuring the input impedance and far field directivity in some control states of combinations between the parasitic elements of the control voltage;
The relationship between the admittance value or impedance value between each antenna element port, the equivalent steering vector, the impedance value of the variable reactance element viewed from the port of each parasitic element, and the far field directivity Admittance value or impedance value between the equivalent steering vector and each antenna element port by substituting the measured impedance value and the impedance value of the variable reactance element as seen from the port of each parasitic element in the above-mentioned several controlled voltage settings And calculating.

  According to the method for measuring the structural parameters of the array antenna according to the third aspect of the present invention described with more limited measurement items, in the measurement method according to the first aspect, the control voltage set for each parasitic element is Three, one of which is a reference control voltage, one of which is a first control voltage, the other is a second control voltage, and combinations of control voltages for each parasitic element that performs input impedance measurement Are all the reference voltages, only one parasitic element is the first control voltage, only two parasitic elements are the first control voltage, and only one parasitic element. It is characterized in that all the combinations in the case where the element is the second control voltage are used.

  According to the method for measuring the structural parameters of the array antenna according to the fourth aspect of the present invention described with more limited measurement items, in the measurement method according to the second aspect, the control voltage set for each parasitic element is Each of the three is a reference control voltage, one of which is a first control voltage and the other is a second control voltage, each of which is used to measure input impedance and far field directivity The control voltage combinations of the elements are all combinations when the control voltages are all the reference voltage and when only one parasitic element is the first control voltage, and only the two parasitic elements are the first control voltage. In this case, the input impedance or the far field in a certain direction is measured in all combinations of the case where only one parasitic element is the second control voltage.

According to the method for measuring the structural parameter of the array antenna according to the fifth aspect of the present invention for measuring the impedance of the variable reactance element using the input impedance measurement method, the feed element for transmitting and receiving a radio signal, and the feed element At least one parasitic element provided at a predetermined distance from the variable element and a variable reactance element connected between the parasitic element and the parasitic element, and each variable reactance element is controlled by the variable reactance element. By changing the reactance value of each variable reactance element by setting a voltage, the directivity changes by operating each parasitic element as a waveguide or a reflector, for example, an electronically controlled waveguide array A method for measuring electrical characteristics of an array antenna as an antenna device,
Measuring an input impedance in a control state in which a control voltage of a variable reactance element of only one parasitic element is arbitrarily set;
Any one of the first to fourth aspects of the relational expression between the admittance value or impedance value between each antenna element port, the impedance value of the variable reactance element viewed from the port of each parasitic element, and the input impedance And inter-port admittance value or impedance value obtained by the above method, and a step of substituting the input impedance measurement value and calculating an impedance value by looking at a variable reactance from a port of a parasitic element in which an arbitrary control voltage is set. It is characterized by that.

According to the measurement method of the electrical characteristics of the variable reactance element that measures the impedance of the variable reactance element using the far field measurement, the power supply element for transmitting and receiving a radio signal is separated from the power supply element by a predetermined interval. At least one parasitic element provided, and a variable reactance element connected between the feeding element and the parasitic element, and a control voltage is set for each of the variable reactance elements, and each of the variable reactance elements is set. A method for measuring the electrical characteristics of an array antenna in which the directivity is changed by operating each parasitic element as a director or a reflector by changing a reactance value of the reactance element,
Measuring a far electric field in a certain direction in a control state in which a variable reactance control voltage of only one parasitic element is arbitrarily set;
The relationship between the admittance value or impedance value between each antenna element port, the equivalent steering vector, the impedance value of the variable reactance element viewed from the port of each parasitic element, and the far electric field is expressed by the second mode or the fourth mode. Substituting the equivalent steering vector, the inter-port admittance value or impedance and value, and the far field measurement value in the above-mentioned certain direction obtained by the method described in the embodiment, the variable reactance can be seen from the port of the parasitic element set with an arbitrary control voltage. And calculating an impedance value.

  According to the measurement method of the electrical characteristics of the variable reactance element according to the seventh aspect of the present invention for measuring the control characteristic of the variable reactance by interpolation, in the measurement method according to the fifth aspect or the sixth aspect, Set the control voltage when calculating the impedance value looking at the variable reactance from the element port to multiple values, and calculate the relationship between the impedance value looking at the variable reactance element from the parasitic element port at multiple control voltages. The control voltage dependence of the impedance of the variable reactance element is obtained by interpolation.

According to the method for measuring the electrical characteristics of the array antenna according to the eighth aspect of the present invention relating to the input impedance calculation method, the feed element for transmitting and receiving a radio signal is spaced apart from the feed element by a predetermined distance. At least one parasitic element provided between the power supply element and the parasitic element, and a control voltage is set for each of the variable reactance elements. A method for measuring the electrical characteristics of an array antenna in which the directivity is changed by operating each parasitic element as a director or a reflector by changing a reactance value of a variable reactance element,
Any one of the first to fourth aspects of the relational expression between the admittance value or impedance value between each antenna element port, the impedance value of the variable reactance element viewed from the port of each parasitic element, and the input impedance Substituting the inter-port admittance value or impedance value obtained by the above method and the impedance value of the variable reactance seen from the port at any control voltage obtained by any method from the fifth aspect to the seventh aspect, An input impedance value in a control state in which each control voltage is set to each parasitic element is calculated.

According to the method for measuring the electrical characteristics of the array antenna according to the ninth aspect of the present invention, which is a method for calculating the directivity of the far field, a feeding element for transmitting and receiving a radio signal, and a predetermined distance from the feeding element At least one parasitic element provided apart from each other, and a variable reactance element connected between the feeding element and the parasitic element, and a control voltage is set for each of the variable reactance elements. And measuring the electrical characteristics of the array antenna in which the directivity is changed by operating each parasitic element as a director or a reflector by changing the reactance value of each variable reactance element. ,
The relationship between the admittance value or impedance value between each antenna element port, the equivalent steering vector, the impedance value of the variable reactance element viewed from the port of each parasitic element, and the far field directivity is expressed in the second mode or The equivalent steering vector obtained by the method described in the fourth aspect, the inter-port admittance value or the impedance value, and any control voltage obtained by the measurement method described in any one of the fifth to seventh aspects. Substituting the impedance value of the variable reactance element viewed from the port, the far field directivity in the control state in which each control voltage is set to each parasitic element is calculated.

According to the method for measuring the electrical characteristics of the array antenna according to the tenth aspect of the present invention, which is a method of calculating input impedance including arbitraryness, the electrical characteristics of the array antenna similar to the method according to the eighth aspect Measuring method,
In order to calculate the admittance or impedance between ports, the method described in the third aspect is used. At this time, as the impedance value of the variable reactance element viewed from the port of each parasitic element in the three control voltage setting states, an appropriate value is used. The input impedance is calculated using three different values.

According to the method for measuring the electrical characteristics of the array antenna according to the eleventh aspect of the present invention, which is a method for calculating the directivity of the far electric field including the arbitrary property, the electric power of the array antenna is the same as the method described in the ninth aspect. Measuring method of mechanical characteristics,
In order to calculate the equivalent steering vector, the method described in the fourth aspect is used, and at this time, the impedance value of the variable reactance element as viewed from the port of each parasitic element in the three control voltage setting states is appropriately different. The directivity of the far electric field is calculated using three values.

According to a method for measuring electrical characteristics of an array antenna according to a twelfth aspect of the present invention, which is a calculation method of input impedance including arbitraryity and has two control voltage setting values, A feed element; at least one parasitic element provided at a predetermined distance from the feed element; and a variable reactance element connected between the feed element and the parasitic element, By setting a control voltage to each variable reactance element and changing the reactance value of each variable reactance element, the directivity characteristics change by operating each parasitic element as a director or a reflector, For example, a method for measuring the electrical characteristics of an array antenna which is an electronically controlled waveguide array antenna device,
There are two control voltages set for each parasitic element, one of which is a reference control voltage, and the combination of control voltages for each parasitic element has two parasitic elements for setting a control voltage other than the reference control voltage. Measuring input impedance with all combinations of
Substituting the measured value of the input impedance measured above into the relational expression between the admittance value or impedance value between each antenna element port, the impedance value of the variable reactance element viewed from the port of each parasitic element, and the input impedance, and For each parasitic element, two variable reactance element impedance values in two control voltage states and the self-admittance of the parasitic element, or between two variable reactance element impedance values in two control voltage states and the parasitic element feed element By substituting appropriate values for the mutual admittance of the variable reactance element in one control voltage state, the self-admittance of the parasitic element, and the mutual admittance between the feeder element and the parasitic element, Temporary admitan Calculating the impedance value of the value or temporary,
Using the temporary admittance value or the temporary impedance value between the ports, any one of the methods from the fifth aspect to the seventh aspect can be used to estimate the variable reactance as viewed from the port of each parasitic element. Calculating an impedance value of
The relationship between the admittance value or impedance value between each antenna element port, the impedance value of the variable reactance element viewed from the port of each parasitic element, and the input impedance is calculated using the above calculated temporary admittance value or temporary value between ports. And substituting the temporary impedance value of the variable reactance element viewed from the port of each parasitic element, and calculating the input impedance in the control state of the control voltage combination of each parasitic element. Features.

According to the method for measuring the electrical characteristics of an array antenna according to the thirteenth aspect of the present invention, which is a method for calculating the directivity of a far electric field including optionality, and has two control voltage setting values, radio signals are transmitted and received. And at least one parasitic element provided at a predetermined distance from the feeding element, and a variable reactance element connected between the feeding element and the parasitic element. Providing a control voltage for each variable reactance element and changing a reactance value of each variable reactance element, thereby causing each parasitic element to operate as a director or a reflector. A method for measuring the electrical characteristics of a changing array antenna,
Distant electric field directivity and input impedance value when two control voltages are set for each parasitic element, one is a reference control voltage, the other is a first control voltage, and all are reference control voltages, Far field directivity and input impedance values of all combinations when only one parasitic element is used as the first control voltage, and a certain direction when the first control voltage is set only for two parasitic elements Measuring the far field or input impedance value of
The relational expression between the admittance value or impedance value between each antenna element port, the equivalent steering vector, the impedance value of the variable reactance element viewed from the port of each parasitic element, and the input impedance value or far field directivity Substituting the measured input impedance and far field directivity measurement, and for each parasitic element, the two impedance values of the variable reactance element and the self-admittance value of the parasitic element in the two control voltage states, or the two control voltages The mutual admittance value between two impedance values of the variable reactance element in the state and the feed element of the parasitic element, or one impedance value of the variable reactance element in one control voltage state, the self-admittance value of the parasitic element, and the feed element Mutual add between feeding elements As drawers value, by substituting the appropriate values, calculating a provisional admittance value or impedance value of the provisional and the temporary equivalent steering vectors between the ports,
Using the provisional admittance value or provisional impedance value between the ports and the provisional equivalent steering vector, the method according to any one of the fifth to seventh aspects is viewed from the port of each parasitic element. Calculate the temporary impedance value of the variable reactance, the admittance value or impedance value between each antenna element port, the impedance value of the variable reactance element viewed from the port of each parasitic element, the equivalent steering vector, and the far field directivity Substituting the temporary admittance value or temporary impedance value between the ports obtained above and the temporary equivalent steering vector and the temporary impedance value of the variable reactance viewed from the port of each parasitic element into the relational expression of Calculate the far field directivity in the control state of the control voltage combination of parasitic elements Tsu, characterized in that it comprises a flop.

The novelty of the invention according to the second embodiment will be described below. In the calculation, three reactance values X _m ⁽⁰⁾ , Xa _m ^(a) , and Xa _m ^(b) are given for each element as a reference. If incorrect values are used, incorrect structural parameters (admittance Ya _mn Or, the impedance Z _mn , the equivalent steering vector u ^v _m or u ⁱ _m ), and the reactance value X _m are calculated, but the correct input impedance Zin and the far field directivity E are calculated even if these incorrect parameters are used. three parameters for each parasitic element that gives for the calculation, the reactance value ^{_{X m (0), Xa m}} (a), instead of _Xa ^{m (b),} the reactance value ^{_{X m (0), Xa m}} (a), even if the admittance _{Ya 0 m,} the reactance value ^{_{X m (0), Xa m}} (a), in the admittance _{Ya mm} , Reactance value _X ^{m (0),} the admittance _Ya 0 m, may be _{Ya mm.}

The difference of the second embodiment from the first embodiment is that the input impedance in a state where only the parasitic elements Am and An are superscripted (a) and the remaining elements are superscripted (0) is Zin _mn ^The notation has been changed from ^(a) to Zin ^(aa) .

  Next, the procedure of the calculation method according to the second embodiment will be described below.

(Step S1001) The reactance values of the parasitic elements are set in three different states, and the input impedance and the far field directivity of those combinations are measured. All measurements are superscript (0), only one superscript (a) and the rest superscript (0), only one superscript (b) the rest superscript (0), two elements superscript ( a) Superscript (0) for the rest, input impedance measurements are all superscript (0), only one superscript (a) is superscript (0), and only one element with far field directivity With respect to the structural parameter (admittance Ya _mn or impedance Z _mn and equivalent steering from the reactance values and measured values of three gains in one direction when only one is superscript (b) and the rest is superscript (0) Calculate the vector u ^v _m or u ^im ).

(Step S1002) An input impedance or a far electric field in a certain direction when a variable reactance element having an unknown reactance value is loaded on a certain parasitic element is measured, and from the measured value and the structural parameter obtained previously, The reactance value in that state is calculated. The reactance values of several control states are obtained in the same manner, and the control characteristic (applied voltage versus capacity characteristic) of the continuous variable reactance element 12 is obtained by interpolation.

(Step S1003) The antenna characteristics (specifically, input impedance and far field directivity) when each parasitic element is in an arbitrary control state, the structural parameter obtained in Step 1001, and the reactance obtained in Step S1002 Can be calculated from the value (without taking measurements).

(Step S1004) If the correct actual value seen from each port is used as the reactance value of the three control states for each element used as the reference in the calculation in Step S1001, the correct structural parameter is further obtained in Step S1001. A correct reactance value in each control state is calculated in S1002 and a correct antenna characteristic is calculated in Step S1003. If an incorrect value is used, an incorrect structure parameter and reactance value are calculated. The antenna characteristics calculated in step S1003 using incorrect parameters are correct. This is because even if the calculated structural parameter or reactance value is not correct from the assumed port, there is a degree of freedom to be correct for another port position. It has been found that when the admittance Y and the equivalent steering vector u are calculated from the relational expressions of the parameters X, Y, and u, the reactance value X can be appropriately given. However, instead of the reactance value X, the admittance Y is appropriately set. Can be given as a value. That is, regarding each parasitic element Am, X _m ⁽⁰⁾ , Xa _m ^(a) , Ya _0m may be used instead of the reactance values X _m ⁽⁰⁾ , Xa _m ^(a) , Xa _m ^(b) , respectively. , reactance value ^{_{X m (0), Xa m}} (a), even if the admittance _{Ya mm,} reactance value _X ^{m (0),} the admittance _Ya 0 m, may be given appropriate the _{Ya mm.} In this case, measurement in the measurement state (b) becomes unnecessary.

As a unique effect of the invention according to the second embodiment, the number of times of measurement required for calculating the structure parameter can be reduced by M by the latter three methods. Further, for example, by selecting values that are easy to calculate as admittances Ya _0m and Ya _mm , the calculation can be simplified. Since these parameters are values that always appear in the calculation formula, the benefits are great.

In the above embodiment, the far field or the far electric field is measured. However, the present invention is not limited to this, and the near field measurement (planar scanning method, cylindrical surface scanning method, it is possible to obtain a far-field or far field by using such as a spherical scanning method), instead of measuring the far field or far field with I ² F ² method, a near-field measurement You may measure by the method.

  As shown below, there are several ways to select the measurement amount and the arbitrary parameter, and combinations thereof are also possible. Specifically, there are the following four.

(1) A combination of a measured value and a calculated value is also possible, that is, it is natural that the structural parameter does not depend on the extraction method, but the measured amount may be changed when the step is changed. Specifically, the reactance value X and the far electric field E are calculated using the structural parameter obtained from the measured value of the input impedance Zin, or the reactance value X and the input using the structural parameter obtained from the measured value of the far electric field E. Impedance Zin can be calculated.

(2) The measurement amount used for calculation may be exchanged for the structural parameter. Specifically, calculation of admittance Y _mm (only when X _m ^(a) X _m ^(b) is an arbitrary parameter) or calculation of Y _mn As the measurement value used in the above, the measurement value of the input impedance Zin and the measurement value of the far electric field E may be exchanged.

(3) A combination of usage methods (how to select an arbitrary parameter) for each parasitic element is arbitrary, that is, a certain method (for example, reactance values X _m ^(a) and X _m ^{(b )} for the parasitic elements Am and An. ⁾ Is optional for other parasitic elements Am ′ and An ′ that are different combinations of at least one element number, for example, reactance values X _{m ′} (a) and Y _{0m ′} May be used).

(4) It is free to exchange the measurement amount for each parasitic element, and the measured value of the input impedance Zin is used for the parasitic elements Am and An to calculate the structural parameters and reactance values, and at least one element is used. A measured value of the far field E may be used for the parasitic elements Am ′ and An ′ which are different combinations having different numbers.

The above-described embodiment is summarized as follows. A method for measuring the electrical characteristics of an array antenna according to a first aspect of the present invention includes a feeding element for transmitting and receiving a radio signal, and a plurality of parasitic elements provided at a predetermined interval from the feeding element. And a plurality of variable reactance elements respectively connected to the parasitic elements, and by setting a control voltage to each variable reactance element and changing a reactance value of each variable reactance element, A method for measuring the electrical characteristics of an array antenna whose directional characteristics change by operating a parasitic element as a director or a reflector, respectively,
Measuring an input impedance value Zin ⁽⁰⁾ of the array antenna when a predetermined reference reactance value is set for each variable reactance element;
One of the variable reactance elements is set with a first reactance value which is an addition value obtained by adding the reference reactance value to a first shift reactance value indicating a variation value from the reference reactance value. Measure the input impedance value Zin _m ^(a) of the array antenna when the reference reactance value is set for the variable reactance element and when the variable reactance element for setting the first reactance value is sequentially changed. And steps to
One of the variable reactance elements is a value obtained by adding the reference reactance value to a second deviation reactance value that indicates a variation value from the reference reactance value and is different from the first deviation reactance value. When the second reactance value is set and the reference reactance value is set for another variable reactance element, and when the variable reactance element for setting the second reactance value is sequentially changed, the array antenna Measuring each of the input impedance values Zin _m ^(b) ;
When the first reactance value is set for two of the variable reactance elements and the reference reactance value is set for the other variable reactance elements, and two variable reactances for setting the first reactance value are set. Measuring an input impedance value Zin _mn ^(a) of the array antenna when the elements are sequentially changed so as to include all combinations of the variable reactance elements;
Based on the measured input impedance values Zin ⁽⁰⁾ , Zin _m ^(a) , Zin _m ^(b) and Zin _mn ^(a) , the input impedance values Zin ⁽⁰⁾ , Zin _m ^(a) , Zin _m ^(b) and Zin _mn ^(a) , the first and second shift reactance values, the admittance value between each antenna element including the feeding element and at least one parasitic element of the array antenna, Calculating the plurality of variable conversion admittance values using a relational expression with a plurality of variable conversion admittance values variable-converted to include the reference reactance value;
Based on the calculated plurality of variable conversion admittance values and the reference reactance value, an admittance value between the antenna elements of the array antenna is calculated by performing inverse variable conversion on the calculated variable conversion admittance values. Including the step of.

Further, in the method for measuring the electrical characteristics of the array antenna according to the second aspect of the present invention, the control is performed by applying a predetermined control voltage to one selected variable reactance element among the variable reactance elements. When the reactance value corresponding to the voltage is set and the reference reactance value is set for the other variable reactance elements, and when the control voltage is sequentially changed, the input impedance value Zin _m ^(p) of the array antenna is set. Each measuring step,
Based on the measured input impedance value Zin _m ^(p) and the calculated variable transformation admittance value, the input impedance value Zin _m ^(p) , the variable transformation admittance value, and the selected variable The variable reactance element selected by using the relational expression of the variable impedance element variable value of the variable reactance element variable-converted to include the element impedance value of the reactance element, the reference reactance value, and the predetermined reference resistance value. Calculating a control voltage vs. variable conversion element impedance value characteristic of
Based on the calculated control voltage versus variable conversion element impedance value characteristic of the selected variable reactance element, the variable conversion element impedance value is subjected to inverse variable conversion, thereby controlling the control voltage versus element of the selected variable reactance element. Calculating an impedance value characteristic.

Furthermore, the method for measuring the electrical characteristics of the array antenna according to the third aspect of the present invention includes a power feeding element for transmitting and receiving a radio signal, and a plurality of devices provided at a predetermined interval from the power feeding element. By providing a feed element and a plurality of variable reactance elements respectively connected to the parasitic elements, by setting a control voltage to each variable reactance element and changing a reactance value of each variable reactance element, A method for measuring electrical characteristics of an array antenna in which directivity changes by operating each of the parasitic elements as a director or a reflector,
Measuring the electric field E ⁽⁰⁾ (θ, φ) of the array antenna when a predetermined reference reactance value is set for each variable reactance element;
One of the variable reactance elements is set with a first reactance value that is an addition value obtained by adding the reference reactance value to a first deviation reactance value indicating a variation value from the reference reactance value, Electric field E _m ^(a) (θ, φ) of the array antenna when the reference reactance value is set for the variable reactance element and when the variable reactance element for setting the first reactance value is sequentially changed Measuring each of the
One of the variable reactance elements is a value obtained by adding the reference reactance value to a second deviation reactance value that indicates a variation value from the reference reactance value and is different from the first deviation reactance value. The array antenna when a second reactance value is set and the reference reactance value is set for another variable reactance element, and when the variable reactance element for setting the second reactance value is sequentially changed Respectively measuring the electric field E _m ^(b) (θ, φ ₀ ) at a predetermined azimuth angle φ ₀ of
When the first reactance value is set for two of the variable reactance elements and the reference reactance value is set for the other variable reactance elements, and two variable reactances for setting the first reactance value are set. A step of measuring an electric field E _mn ^(a) (θ, φ ₀ ) at a predetermined azimuth angle φ ₀ of the array antenna when the elements are sequentially changed so as to include all combinations of the variable reactance elements. When,
Measuring an input impedance value Zin ⁽⁰⁾ of the array antenna when the reference reactance value is set to each variable reactance element;
When the first reactance value is set for one of the variable reactance elements and the reference reactance value is set for another variable reactance element, the variable reactance elements for setting the first reactance value are sequentially set. Measuring the input impedance value Zin _m ^(a) of the array antenna when changed, and
Measuring the input impedance value Zin _k ^(b) of the array antenna when the second reactance value is set in one of the variable reactance elements and the reference reactance value is set in another variable reactance element; When,
The measured electric fields E ⁽⁰⁾ (θ, φ), E _m ^(a) (θ, φ), E _m ^(b) (θ, φ ₀ ), and E _mn ^(a) (θ, φ ₀ ) And the measured electric field values E ⁽⁰⁾ (θ, φ), E _m ^(a ) based on the measured input impedance values Zin ⁽⁰⁾ , Zin _m ^(a) and Zin _k ^{(b). )} (Θ, φ), E _m ^(b) (θ, φ ₀ ) and E _mn ^(a) (θ, φ ₀ ), and the measured input impedance values Zin ⁽⁰⁾ , Zin _m ^(a) and Zin _k ^(b) , the first and second shift reactance values, the admittance value between the antenna elements including the feeding element of the array antenna and at least one parasitic element, and the reference reactance value Using a relational expression with multiple variable conversion admittance values that have been converted to include Calculating a plurality of variable transformation admittance value,
Based on the measured electric field E ⁽⁰⁾ (θ, φ) and E _m ^(a) (θ, φ) and the calculated variable conversion admittance value, the electric field E ⁽⁰⁾ (θ, φ ⁾ ) And E _m ^(a) (θ, φ), the first shift reactance value, the calculated plurality of variable transformation admittance values, and each of the array antennas including the plurality of variable transformation admittance values Calculating a variable conversion equivalent steering vector having the variable conversion directivity characteristic function of each antenna element of the array antenna as an element using a relational expression with the variable conversion directivity characteristic function of the antenna element;
Based on the calculated variable conversion equivalent steering vector and the calculated plurality of variable conversion admittance values, the relational expression between the plurality of variable conversion admittance values and the variable conversion equivalent steering vector is used. Calculating an equivalent steering vector for the antenna.

<Supplementary explanation 1>
In the above embodiment, the calculation and measurement method of the electrical characteristics of the array antenna has been described. However, the calculation can be performed by a digital computer (hardware resource) having a predetermined processing memory. If the structure parameter is arbitrary, it is derived that the input impedance Zs of the feeder circuit can be calculated by any of the following equations. Confirmed with.

<Supplementary explanation 2>
Next, a relational expression for extracting the structural parameters of the array antenna from the far electric field E (θ, φ) of the array antenna is derived below. Here, when the observed quantity is the input impedance Z _in , this is expressed by the following equation.

Further, the port current i ₀ flowing through the parasitic element A0 is expressed by the following equation.

  Next, the far field E (θ, φ) of the array antenna is expressed by the following equation.

Here, the input impedance Z _in is calculated from the port current i ₀ flowing through the parasitic element A 0, and the current i ₀ is represented by the product of the admittance matrix [Ya _0m ] and the voltage vector [va _m ]. On the other hand, the far electric field E (θ, φ) is expressed by the product of the equivalent steering vector [u _m (θ, φ)] and the voltage vector [va _m ]. The only difference in these relational expressions is that the admittance matrix [Ya _0m ], which is a structural parameter, is changed to an equivalent steering vector [u _m (θ, φ)]. Here, the voltage vector [va _m ] is expressed as follows in both cases.

Here, the port current i _m is the unknown, the reactance value other than the reactance values Xa _m is expressed as follows when the 0.

Moreover, it can be simplified as follows when the reactance value other than the reactance values Xa _m and Xa _n is 0.

Here, the difference between the admittance matrix [Ya _0m ] expressed in the relational expression of the port current i ₀ and the equivalent steering vector [ua _m (θ, φ)] expressed in the relational expression of the far electric field E (θ, φ) is equivalent steering vector _{[ua m (θ, φ)} ] and it is a function of direction, admittance matrix admittance matrix [Ya 0 _m] in terms of a parameter which appears in the expression for the port current i _m of antenna elements Am is there. If the direction is fixed, the former difference is eliminated. In addition, because of the latter difference, only the admittance matrix [Ya _mn ] appears _{in the} relational expression related to the input impedance Z _in, so that it can be solved for the admittance matrix [Ya _mn ], but the relation regarding the far electric field E (θ, φ) The equation includes an equivalent steering vector [ua _m (θ, φ)] and
Since admittance matrix _{[Ya 0 m] appears, Ya 0m ua m (θ,} φ) would not be solved only for only.

Next, the reactance values Xm ^(a) and Xm ^(b) are known for each antenna element, and only the antenna element Am is loaded with a variable reactance element having the value of the reactance value Xam ^(a) or Xm ^(b). all reactance values Xa _n of the variable reactance element that is loaded in the antenna element is measured 0 at which the input impedance _Zin ^m control state ^(a) and _Zin ^{m (b),} further reactance to the antenna element Am of is loaded to the variable reactance element values Xa m ^_(a), the antenna element An is loaded to the variable reactance element of the reactance value Xa n ^_(b), the reactance value Xa _n of all remaining variable reactance element is 0 The input impedance Zin _mn ^(aa) in the controlled state is measured, and from the value, equations (21) and (21 The admittance value Ya _mn is calculated from 22), (24), (25), and (26).

Similarly, for each antenna element, the reactance values Xa _m ^(a) and Xa _m ^(b) are known, and only the antenna element Am has a variable reactance of the reactance value Xa _m ^(a) or Xa _m ^(b) . element is loaded, by measuring the electric far field ^Em control state reactance values Xa _n of all remaining variable reactance element is a ^{0 (a) (θ, φ} ) and ^{Em (b) (θ, φ} ), further The antenna element Am is loaded with a variable reactance element having ^a reactance value Xa _m ^(a) , the antenna element An is loaded with a variable reactance element having a reactance value Xa _n ^(b) , and reactances of all the remaining variable reactance elements. value Xa _n is 0 in a control state of the electric far field ^{Emn (aa)} (theta, phi) measured, equation (23) from its value, (24), (25), Than 26), Ya0muam (θ, φ) is calculated.

  These more specific formulas are described below. First, when only one or two reactance values are non-zero, the port current can be solved as follows.

here,

here,

Here, a reactance value of the variable reactance elements other than the reactance values Xa _m is as follows when 0.

Also, the reactance value of the variable reactance elements other than the reactance values Xa _m and Xa _n are is as follows when 0.

Using such a port current, the measured input impedance Zin and the far electric field E (θ, φ) can be solved as follows. Here, the port current i ₀ of the power feeding element A 0 that is in one-to-one relationship with the input impedance Zin is expressed by the following equation.

Here, when the reactance value of the reactance elements other than the reactance values Xa _m is 0, the port current i ₀ is given by the following equation.

Using the above equation, measured values of input impedances Zin _m ^(a) and Zin _m ^{(b )} when a variable reactance element having ^a reactance value Xa _m ^(a) or Xa _m ^(b) is loaded only on the antenna element Am. ⁾ , The admittance values Ya _0m and Ya _mm can be solved.

Here, when the reactance value of the variable reactance elements other than the variable reactance element of the reactance value Xa _m and Xa _n is 0, the port current i ₀ is expressed by the following equation.

Here, using the above equation, the input in the state where the variable reactance element of the reactance value Xa _m ^(a) is loaded on the antenna element Am and the variable reactance element of the reactance value Xa _n ^(b) is loaded on the antenna element Am. The admittance value Ya _mn can be solved from the measured impedance value Zin _mn ^(aa) .

Here, the array antenna far field E (theta, phi) when the reactance value of the variable reactance elements other than the reactance values Xa _m is 0, it is expressed by the following equation.

Here, using the above formula, the measured value Em ^(a) of the far field of the array antenna when only the antenna element Am is loaded with the variable reactance element having the reactance value Xa _m ^(a) or Xam ^{(b ).} From (θ, φ) and Em ^(b) (θ, φ), ua _m (θ, φ) Ya _0m and the admittance value Ya _mm can be solved. If the admittance value Ya _0m is calculated from the measurement of the input impedance, the equivalent steering vector ua _m (θ, φ) can be calculated. Here, when the reactance value of the variable reactance elements other than the reactance values Xa _m and Xa _n is 0, the array antenna far field E (theta, phi) is expressed by the following equation.

here,

Here, using the above equation, the antenna element Am is loaded with a variable reactance element having ^a reactance value Xa _m ^(a) , and the antenna element An is loaded with a variable reactance element having a reactance value Xa _n ^(b) From the measured value Emn ^(aa) (θ, φ) of the far field of the array antenna in Fig. 4, the parameters Ya _mm , Ya _0m , ua (θ, φ), and Ya _nn , Ya _0n and ua _n (θ, φ) The admittance value Ya _mn can be solved from the value.

It is a block diagram which shows the structure of the control apparatus of the array antenna which concerns on the 1st Embodiment of this invention. It is a longitudinal cross-sectional view which shows the detailed structure of the array antenna apparatus 100 of FIG. FIG. 6 is a schematic diagram showing a comparison between a method for measuring and calculating the electrical characteristics of the array antenna apparatus of the present embodiment and a pole near-field measurement method using a conventional current measurement probe 300. It is the table | surface which compared the measurement and calculation method of the electrical property of the array antenna apparatus of this embodiment shown by FIG. 3, and the conventional pole near field measurement method. It is the schematic which shows the port position p1 in the parasitic element Am of the array antenna apparatus 100 of FIG. 6 is a graph showing reactance value versus impedance value characteristics when a distance δ = λ / 10 between port positions p1 and p3 in FIG. 5; 6 is a graph showing a reactance value versus impedance value characteristic when a distance δ = λ / 20 between port positions p1 and p3 in FIG. 5; 6 is a graph showing reactance value versus impedance value characteristics when a distance δ = 0 between port positions p1 and p3 in FIG. 5; A lumped circuit model for ports in the parasitic elements Am of the array antenna apparatus 100 of FIG. 1 is a schematic diagram showing a virtual port p4 of the voltage va _m. The measurement items and the number of times of measurement in the input impedance value measurement which is the first embodiment and the far field directivity measurement which is the second embodiment in the measurement and calculation method of the electrical characteristics of the array antenna apparatus of FIG. It is a table | surface which shows. It is a block diagram which shows the structure of the structural parameter measurement calculation system of the array antenna apparatus 100 using the input impedance value measurement based on the 1st Example which concerns on the 1st Embodiment of this invention. FIG. 12 is a first part of a flowchart showing a measurement calculation process of a structure parameter of the array antenna apparatus, which is executed by the measurement computer 50 of FIG. 11. FIG. 12 is a second part of a flowchart showing a measurement calculation process of the structural parameters of the array antenna apparatus, which is executed by the measurement computer 50 of FIG. 11. It is a flowchart which shows the subroutine which concerns on measurement process S23 of the variable reactance element of FIG. It is a flowchart which shows the subroutine which concerns on calculation process S24 of the reactance value versus input impedance value characteristic of the array antenna apparatus of FIG. It is a block diagram which shows the structure of the structural parameter measurement calculation system of the array antenna apparatus 100 using the far-field directivity measurement based on 2nd Example based on 1st Embodiment of this invention. FIG. 17 is a first part of a flowchart showing a measurement calculation process of structure parameters of the array antenna apparatus, which is executed by the measurement computer 60 of FIG. 16. FIG. 17 is a second part of a flowchart showing a measurement calculation process of the structure parameter of the array antenna apparatus, which is executed by the measurement computer 60 of FIG. 16. FIG. 17 is a third part of a flowchart showing a measurement calculation process of the structural parameters of the array antenna apparatus, which is executed by the measurement computer 60 of FIG. 16. It is a flowchart which shows the electric field E ⁽⁰⁾ ((phi)) measurement process (S63) of a far field which is a subroutine of FIG. It is a flowchart which shows the electric field _Em ^(a) ((phi)) measurement process (S65) of a far field which is a subroutine of FIG. FIG. 18 is a flowchart showing a far-field electric field E _m ^(b) (φ ₀ ) measurement process (S 67) that is a subroutine of FIG. 17. It is a flowchart which shows the electric field _Emn ^(a) ((phi) ₀ ) measurement process (S69) of a far field which is a subroutine of FIG. It is a flowchart which shows the measurement process (S85) of the variable reactance element which is a subroutine of FIG. It is a flowchart which shows the reactance value vs. far-field directivity calculation process (S86) of the array antenna apparatus which is a subroutine of FIG. It is a perspective view which shows the structure of the array antenna apparatus 110 based on the 3rd Example of this invention which replaces the array antenna apparatus 100 of FIG. 27 is a table showing reactance values set for each variable reactance element 12-m of the array antenna apparatus 110 in the simulation related to the array antenna apparatus 110 of FIG. FIG. 27 is a table showing simulation results for the array antenna apparatus 110 of FIG. 26 and showing calculated admittance values Y _mn between the antenna elements of the array antenna apparatus 110. FIG. It is a simulation result which concerns on the array antenna apparatus 110 of FIG. 26, Comprising: It is a graph which shows the amplitude of the equivalent steering vector of the array antenna apparatus 110. It is a simulation result which concerns on the array antenna apparatus 110 of FIG. 26, Comprising: It is a graph which shows the phase of the equivalent steering vector of the array antenna apparatus 110. FIG. 6 is a graph showing an impedance value Z characteristic with respect to a control voltage _{VDC in} a single variable reactance element used in the array antenna apparatus 100 of FIG. 4 is a table showing simulation results according to the first embodiment of the present invention, and showing calculated admittance values Y _mn between antenna elements of the array antenna apparatus 100. 5 is a graph showing the result of simulation according to the first embodiment of the present invention, and showing the calculated amplitude of an element u _m ⁱ (φ) of an equivalent steering vector of the array antenna device 100. 6 is a graph showing the result of a simulation according to the first embodiment of the present invention and showing the phase of a calculated element u _m ⁱ (φ) of an equivalent steering vector of the array antenna device 100. FIG. 4 is a simulation result according to the first embodiment of the present invention, and shows an impedance value Z characteristic with respect to a control voltage V _DC3 of a variable reactance element 12-3 loaded on a parasitic element A3 of the array antenna apparatus 100 of FIG. It is a graph to show. 3 is a table showing sets of control voltages V _{DC1 to} V _DC6 set in the variable reactance elements 12-1 to 12-6 of the array antenna apparatus 100 of FIG. 1 in the simulation according to the first embodiment of the present invention. is there. It is a simulation result which concerns on the 1st Embodiment of this invention, Comprising: It is a table | surface which shows the input impedance value Zin of the array antenna apparatus 100 when the control voltage set of cases 1-3 of FIG. 36 is set. FIG. 37 is a graph showing simulation results according to the first embodiment of the present invention and showing a directivity pattern of gain when the control voltage set of case 1 in FIG. 36 is set in the array antenna apparatus 100. FIG. FIG. 37 is a graph showing the directivity pattern of the phase when the control voltage set of case 1 in FIG. 36 is set in the array antenna apparatus 100, which is a simulation result according to the first embodiment of the present invention. FIG. 37 is a graph showing simulation results according to the first embodiment of the present invention and showing a directivity pattern of gain when the control voltage set of case 2 in FIG. 36 is set in the array antenna apparatus 100. FIG. FIG. 37 is a graph showing the directivity pattern of the phase when the control voltage set of case 2 of FIG. 36 is set in the array antenna apparatus 100, which is a simulation result according to the first embodiment of the present invention. FIG. 37 is a graph showing simulation results according to the first embodiment of the present invention, and showing a directivity pattern of gain when the control voltage set of case 3 in FIG. 36 is set in the array antenna apparatus 100. FIG. FIG. 37 is a graph showing the directivity pattern of the phase when the control voltage set of case 3 in FIG. 36 is set in the array antenna apparatus 100, which is a simulation result according to the first embodiment of the present invention. It is a figure for demonstrating the process which concerns on the 2nd Embodiment of this invention, Comprising: It is a block diagram which shows the relationship between the structural parameter, variable value, and measured value of an electronically controlled waveguide array antenna apparatus. It is a table | surface which shows the relationship between the number of the measured quantities and the number of unknowns in 2nd Embodiment. It is a table | surface which shows the change of the parameter which has no influence on input impedance in 2nd Embodiment. It is a table | surface which shows the calculation formula of the impedance value of an admittance matrix and the variable reactance element 12 in 2nd Embodiment. It is a perspective view which shows an external appearance when feeding element A0 has shifted | deviated from the center in a 7-element electronically controlled waveguide array antenna apparatus. It is a table | surface which shows the actual reactance value used in the numerical calculation which concerns on 2nd Embodiment. It is a table | surface which shows the reactance value input into a calculating formula in the numerical calculation which concerns on 2nd Embodiment. It is a numerical calculation result in 2nd Embodiment, Comprising: It is a graph which shows the control characteristic (1st variable reactance element 12-1) of a variable reactance element. It is a table | surface which shows the reactance value for calculating an antenna characteristic in 2nd Embodiment. It is a table | surface which shows the impedance value calculated from a derived parameter in 2nd Embodiment. It is a numerical calculation result of 2nd Embodiment, Comprising: It is a graph which shows the far field directivity computed from a derived parameter.

Explanation of symbols

A0, A10 ... feeding element,
A1 to A6, A11 to A16 ... parasitic elements,
1 ... Low noise amplifier (LNA),
2 ... Down converter,
3 ... A / D converter,
4 ... demodulator,
5 ... Coaxial cable for feeding,
6 ... circulator,
7 ... Wireless transmitter,
11, 111 ... grounding conductor,
12-1 to 12-6 ... variable reactance element,
20 ... Adaptive control type controller,
21 ... Learning sequence signal generator,
30 ... Control voltage controller,
31 ... Control voltage table memory,
L1 ... distributed constant line,
p1, p2, p3 ... port position,
p4 ... Virtual port,
40 ... Network analyzer,
41 ... wireless transmitter,
42 ... wireless receiver,
43 ... Horn antenna device,
50, 60 ... measuring computer,
51 ... Azimuth and elevation controller,
52 ... Initial value memory,
53 ... CRT display
54 ... Processing memory,
61 ... switch,
100, 110 ... array antenna device,
101, 102 ... support stand,
200 ... Anechoic chamber.

Claims (6)

A power feeding element for transmitting and receiving wireless signals;
At least one parasitic element provided at a predetermined interval from the feeding element;
And at least one variable reactance element connected to each parasitic element,
By setting a control voltage for each of the variable reactance elements and changing a reactance value of each of the variable reactance elements, the directivity characteristics are changed by operating each parasitic element as a director or a reflector. An apparatus for measuring the electrical characteristics of an array antenna,
The array antenna is configured to apply at least three control voltages to each of the variable reactance elements, and in a plurality of first control states of all combinations of the control voltages for the variable reactance elements. Means for measuring the input impedance of
Based on the measured input impedance and the impedance value of the variable reactance element viewed from each parasitic element in each first control state, the array antenna feeding element and at least one parasitic element are The relationship which shows the relationship between the admittance value or impedance value between each antenna element of a plurality of including antenna elements, the impedance value of each variable reactance element viewed from each parasitic element, and the input impedance of the array antenna An apparatus for measuring the electrical characteristics of an array antenna, comprising means for calculating an admittance value or an impedance value between the antenna elements using an equation. A power feeding element for transmitting and receiving wireless signals;
At least one parasitic element provided at a predetermined interval from the feeding element;
And at least one variable reactance element connected to each parasitic element,
By setting a control voltage for each of the variable reactance elements and changing a reactance value of each of the variable reactance elements, the directivity characteristics are changed by operating each parasitic element as a director or a reflector. An apparatus for measuring the electrical characteristics of an array antenna,
The array antenna is configured to apply at least three control voltages to each of the variable reactance elements, and in a plurality of second control states of all combinations of the control voltages for the variable reactance elements. Means for measuring the input impedance and far-field directivity of
Based on the measured input impedance and far field directivity, and the impedance value of the variable reactance element viewed from each parasitic element in each second control state, at least one feeding element of the array antenna The admittance value or impedance value between the antenna elements of the plurality of antenna elements including the parasitic elements, the equivalent steering vector of the array antenna, and the impedance values of the variable reactance elements viewed from the parasitic elements, respectively And means for calculating an equivalent steering vector of the array antenna and an admittance value or an impedance value between the antenna elements, using a relational expression indicating a relation between the input impedance of the array antenna and a far field directivity characteristic. Alle characterized by having Apparatus for measuring the electrical characteristics of the antenna. The apparatus for measuring electrical characteristics of an array antenna according to claim 1 or 2,
The array antenna in the third control state when the variable reactance element connected to one parasitic element is set to apply a control voltage whose impedance value of the variable reactance element is unknown. Means for measuring the input impedance of
Based on the input impedance measured in the third control state and the calculated admittance value or impedance value between the antenna elements, the admittance value or impedance value between the antenna elements, A relational expression indicating the relationship between the impedance value of each variable reactance element viewed from the port of the feed element and the input impedance of the array antenna is used to determine whether the variable reactance element connected to the variable reactance element in the third control state is connected. An apparatus for measuring the electrical characteristics of an array antenna, comprising: means for calculating an impedance value of a variable reactance element viewed from a feeding element. The apparatus for measuring electrical characteristics of an array antenna according to claim 2,
The array antenna in the fourth control state when the variable reactance element connected to one parasitic element is set to apply a control voltage whose impedance value of the variable reactance element is unknown. Means for measuring the far-field directivity in a predetermined direction of
Based on the far-field directivity characteristics of the array antenna in a predetermined direction measured in the fourth control state, the measured equivalent steering vector of the array antenna, and the admittance value or impedance value between the antenna elements. The relationship between the admittance value or impedance value between the antenna elements, the equivalent steering vector and far-field directivity of the array antenna, and the impedance values of the variable reactance elements viewed from the ports of the parasitic elements, respectively. Means for calculating the impedance value of the variable reactance element as seen from the parasitic element connected to the variable reactance element in the fourth control state using the relational expression shown in FIG. Measuring device for electrical characteristics. A power feeding element for transmitting and receiving wireless signals;
At least one parasitic element provided at a predetermined interval from the feeding element;
And at least one variable reactance element connected to each parasitic element,
By setting a control voltage for each of the variable reactance elements and changing a reactance value of each of the variable reactance elements, the directivity characteristics are changed by operating each parasitic element as a director or a reflector. An apparatus for measuring the electrical characteristics of an array antenna,
An admittance value or an impedance value between the antenna elements measured by using the array antenna electrical characteristic measuring device according to claim 1 or 2, and an electrical characteristic measurement of the array antenna according to claim 3 or 4. Each antenna element based on the impedance value of the variable reactance element viewed from a parasitic element connected to the variable reactance element in the third control state or the fourth control state measured using a device Using the relational expression showing the relationship between the admittance value or the impedance value between them, the impedance value of each variable reactance element viewed from each parasitic element, and the input impedance of the array antenna, The input impedance value in the fifth control state in which each predetermined control voltage is set is measured. Apparatus for measuring electrical characteristics of an array antenna, characterized in that a means for. A power feeding element for transmitting and receiving wireless signals;
At least one parasitic element provided at a predetermined interval from the feeding element;
And at least one variable reactance element connected to each parasitic element,
By setting a control voltage for each of the variable reactance elements and changing a reactance value of each of the variable reactance elements, the directivity characteristics are changed by operating each parasitic element as a director or a reflector. An apparatus for measuring the electrical characteristics of an array antenna,
An equivalent steering vector of the array antenna and an admittance value or an impedance value between the antenna elements measured using the apparatus for measuring the electrical characteristics of the array antenna according to claim 2, and the electricity of the array antenna according to claim 4. And the equivalent steering vector of the array antenna based on the impedance value of the variable reactance element viewed from the parasitic element connected to the variable reactance element in the fourth control state, which is measured using the measurement device for the characteristic characteristics And an admittance value or impedance value between each antenna element, an impedance value of each variable reactance element viewed from each parasitic element, and a relational expression indicating a relationship between the far field directivity characteristics of the array antenna. Predetermined control voltages to the parasitic elements. Set the sixth measuring device of the electrical characteristics of an array antenna, characterized in that a means for calculating the far-field directional characteristics of the array antenna in the control state.

Images