JP2001044740A - Feeding method and phased array antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a feeding method and a phased array antenna by which phase compensation is conducted to obtain an excellent antenna pattern even in the case that the antenna has distortion. SOLUTION: In the feeding method for the phased array antenna employing a matrix circuit 20 that decides a beam direction depending on a position of a feeding port, a center phase in an output of the matrix circuit 20 is made constant independently of a position of the feeding port. Signals of 3 feeding ports or over of the matrix circuit 203 are distributed and synthesized according to a power density distribution and a phase distribution obtained by a Gauss function for complex number coefficients in which sin[θs]-sin[θi] and sin[ϕs]-sin[ϕi] are used for variables, where (θi, ϕi) are direction of a beam when power is fed to a feeding port (i, j) of the matrix circuit 20 and (θs, ϕs) is a desired beam direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phased array antenna using a matrix circuit whose beam direction is determined by the position of a feed port, and more particularly, to a feed method for controlling a phase distribution of an antenna aperture and a feed method using the same. A phased array antenna having a feeding circuit.

[0002]

2. Description of the Related Art A phased array antenna using a matrix circuit in which the beam direction is determined by the position of a power supply port changes the beam direction in accordance with the position of a power supply point (port of a matrix circuit for supplying power). It is called a feeding point switching scanning type phased array antenna.

In general, the fineness of scanning (interval between individual beams) is about the beam width, and it is characterized in that several multi-beams can be generated by appropriately selecting a signal input port. ing. [Refer to Literature: IEICE “Antenna Engineering Handbook”, Chapter 5, Chapter Ohmsha] FIG. 8 is a diagram illustrating a direct radiation type phased array antenna using an N-port one-dimensional matrix circuit.
In the figure, numeral 6 indicates an input signal, 7 indicates a matrix circuit, 8 indicates an element antenna, and 1 to 5 indicate beam directions. The input signal 6 is an input position (in this case, any one of port 1 to port N) according to a desired beam direction.
Select and enter.

A Butler matrix or the like is used as the matrix circuit 7 in FIG. 1, 2, and 3 indicate beam directions when signals are supplied from port 1, port 2, and port 3, respectively, and 4, 5 indicate port i and port i, respectively.
The beam direction when a signal is supplied from port N is shown.

[0005] The signal input to the matrix circuit 7 is distributed in the matrix circuit and output with a different phase difference for each port. Since the phase gradient generated on the output side varies depending on the position of the signal input port, the beam direction changes in accordance with the port position of the matrix circuit that supplies power.

In general, the power input from the feeding point is equally distributed by the matrix circuit, so that the excitation distribution on the aperture plane becomes uniform, and if the element antenna (radiation element) is excited with the same amplitude intensity, the side lobe characteristic is obtained. Is bad. Further, the number of beams and the beam direction of the feeding point switching scanning antenna are restricted by the number of feeding points (the number of ports of the matrix circuit). To solve these problems at the same time, an antenna has been proposed which feeds a signal to three or more ports of a matrix circuit in the same phase (the same phase).
[Literature: Kira et al., "One Construction Method of Multi-beam Matrix Antenna Having Good Pattern Characteristics", 1998 IEICE Society Conference, B-1-70, p.
FIG. 9 illustrates this. In the figure, numeral 6 is an input signal, 9 is a variable power distribution circuit (operates the distribution ratio of signal power according to the beam direction; all signal phases are in phase), 7 is a matrix circuit, and 8 is an element. Shows the antenna. The input signal 6 is distributed by the variable power distribution circuit 9 and supplied to three or more ports in the same phase.

[0007] The signal power supplied to each port is represented by a real coefficient Gaussian function A exp [-BX ² ] standardized so that the integral value is 1 (area is 1). By executing definite integration. FIG. 10 illustrates this. The coefficient A is a normalization coefficient for setting the integral value of the Gaussian function to 1, and the coefficient B is a parameter that defines the spread of the Gaussian function.

[0008] The principle of this antenna is based on the following idea.

The reason that the beam direction changes according to the position of the port to which the power is supplied by the phased array antenna using the matrix circuit is that the input signal is distributed by the matrix circuit and at the same time, the output of each of the ports depends on the position of the port to which the power is supplied. This is because the phase of the signal at the port rotates, causing a tilt in the phase plane. This can be considered as performing Fourier transformation in principle.

A Gaussian function a exp (−bx) where x is a variable
² ) is a Gaussian function c exp
(−dx ² ). a, b, c, and d are coefficients. That is, when the input signal is supplied to the matrix circuit with a Gaussian function amplitude distribution, the output signal also has a Gaussian amplitude distribution. Since the power of the signal is proportional to the square root of the amplitude, when the amplitude distribution is represented by a Gaussian function, the power distribution is also a Gaussian function. A side lobe characteristic is improved by giving a Gaussian function type taper to the amplitude distribution of the aperture surface.

Also, due to the nature of the Fourier transform, if the power supply position (the position of the power supply port) is shifted while the distribution shape of the input signal remains unchanged, the slope of the output signal phase plane changes only by a constant value. The plane amplitude distribution itself does not change. That is, the beam pattern (amplitude distribution of the aperture surface)
, It is possible to continuously change only the beam direction. This property is called transition of the time axis in the Fourier transform.

FIG. 11 shows a calculation result of an antenna pattern according to the prior art. The antenna is a 16-element linear array (the number of ports of the matrix circuit N = 16) with an element spacing of 0.68 wavelength.

In the power density distribution A exp [-BX ² ], when the variable X is a unit of the beam width for one port (the variable X represents N when the width of the N-port matrix circuit is expressed), the coefficient B Is 4.0, and the normalization coefficient A at this time is 1.13. In this case, the edge taper (excitation amplitude ratio of the element at both ends to the element at the center) of the amplitude distribution of the antenna aperture is -10.7 dB.

In FIG. 1, numerals 13, 14, and 15 indicate beam directions of -13.2 °, -14.6 °, and -1 respectively.
This is a 6.0 ° beam pattern. In FIG. 11, numeral 13 indicates a case where the peak position of the power density distribution is at the position of the port 11, and numeral 15
Is the peak position of the power density distribution at port 11 and port 12.
In the case of being located in the middle of FIG. At this time, the number of ports used for power supply is four.

That is, in FIG. 11, numeral 13 and numeral 15 indicate the case where the power density distribution is the same as shown in FIG. 10, but the power ratio supplied to the four power supply ports is different. What is shown in FIG. 11 is that even when the power ratio supplied to the four ports is changed, a radiation pattern having substantially the same beam pattern and a different beam direction can be obtained.

In a linear array antenna or a planar array antenna, the ideal phase distribution of the aperture surface is a straight line or a flat surface without distortion, but in an actual antenna, distortion occurs in the antenna aperture due to thermal deformation and manufacturing variations. FIG.
FIG. 2 illustrates this, which appears as a phase error in the excitation distribution on the antenna aperture. That is, the element antenna 8
Distorted antenna surface 41 and ideal antenna surface 4
If 0 is the width of 0.2 wavelength, a phase difference of 72 ° occurs. FIG. 13 shows the results 16, 17, and 18 of the prior art antenna pattern calculated under the above-described conditions (the same power supply conditions as in FIG. 11) when + 72 ° second-order phase distortion exists at both ends of the antenna aperture. A phase distortion of 72 ° corresponds to a distortion of the antenna aperture by ５ wavelength, and a 15 GHz antenna corresponds to a distortion of 4 mm because one wavelength is 2 cm. It can be seen that the antenna pattern greatly changes even with such a small value. The main lobe is indistinguishable from the first side lobe, and the gain is deteriorating, though.

In order to avoid this, there can be considered an approach of structurally increasing the rigidity of the antenna and an electrical approach of correcting a phase distortion by inserting a phase shifter between the element antenna and the matrix circuit. However, there is a limit in the method of structurally increasing the rigidity of the antenna, and at the same time, the weight of the antenna is increased. Also, the method of directly adjusting the phase of an element antenna using a phase shifter or the like not only complicates the antenna configuration but also requires a large amount of time and effort to adjust the phase shifter, which is required in large quantities according to the number of element antennas. Become.

When a reflector and an array are combined, an element antenna is arranged on a curved surface or a phase shifter is installed to radiate a radio wave close to a spherical wave from the array to the reflector. For example, a secondary distribution is intentionally given to the phase plane. [Literature: Kobayashi et al., “Microwave FFT
Examination of Radiation Characteristics of Multi-beam Antenna for Satellite Mounted Using Circuit in Beam Forming Network ", 1997-13, Conference on Space Science and Technology, 97-13-6, also in this case, there is a problem that the antenna configuration becomes complicated. .

In the above discussion, a one-dimensional linear array has been described. However, even if the function has two variables x and y (the matrix circuit is two-dimensional), the Fourier transform is performed independently for each variable. A similar argument holds, resulting in the problem of variables. That is, the function a exp [−bx ² ], e e
The Fourier transform of xp [−fy ² ] is c exp [−d
x ² ] and g exp [−hy ² ], the horizontal distribution of the input signal in the two-dimensional matrix circuit is a exp [−
bx ² ] and the vertical distribution as e exp [−fy ² ],
The horizontal and vertical distributions of the output are c exp [−d
x ² ], g exp [−hy ² ], and the beam pattern formed by the antenna is 1 in the horizontal direction and the vertical direction.
Reduced in the case of dimensions.

[0020]

In the above-mentioned conventional antenna, when a distortion is present in the antenna, the antenna pattern is greatly changed. If this is solved by a method such as increasing the rigidity of the antenna, the weight of the antenna increases. In addition, the method of correcting the phase distortion caused by the distortion of the antenna using the phase shifter or the like has a problem that not only the antenna configuration is complicated but also a great deal of time is required for adjusting the phase shifter. Further, there is a problem that the antenna configuration is similarly complicated when a quadratic distribution is intentionally given to the phase plane of the array, for example, when a reflecting mirror and an array are combined.

The present invention has been made in view of the above circumstances, and a small-scale control circuit is used to add a secondary component of an arbitrary size to the phase distribution of the excitation distribution (output of the matrix circuit) on the antenna aperture. It is an object of the present invention to provide a power feeding method and a phased array antenna which can perform the phase compensation and obtain a good antenna pattern even when distortion is present in the antenna.

[0022]

In order to achieve the above object, the present invention provides a method for feeding a phased array antenna using a matrix circuit in which a beam direction is determined by the position of a feed port. The center phase is constant regardless of the position of the feed port,
When the beam direction when power is supplied to the power supply port (i, j) of the matrix circuit is (θ _i , φ _j ) and the desired beam direction is (θ _s , φ _s ), sin [θ _s ] −sin
Distributes signals to three or more power supply ports of the matrix circuit according to a power density distribution and a phase distribution obtained by a Gaussian function of a complex number coefficient having [θ _i ] and sin [φ _s ] −sin [φ _i ] as variables. Or combining signals from three or more power supply ports of the matrix circuit.

Further, the present invention is characterized in that, in the power supply method, power is supplied using three or more power supply ports for only one of the power supply ports (i, j), i and j.

For example, when the matrix circuit is a two-dimensional matrix circuit having N ports in the horizontal direction and M ports in the vertical direction, the power supply ports (i, j) (i = 1, 2, 3,...,
N) When the present invention is applied using three or more feed ports only for i (or j) of (j = 1, 2, 3,..., M), antenna characteristics only in the horizontal direction (or vertical direction) It is intended to improve. When N = 1 or M = 1, the antenna is a one-dimensional linear array antenna.

According to another aspect of the present invention, there is provided a phased array antenna using a matrix circuit in which a beam direction is determined according to the position of a power supply port. It is characterized by having a circuit.

As described above, in the conventional antenna, when adjusting the phase distribution of the aperture surface, the phase of each element antenna is directly adjusted using a phase shifter or the like.

Port (i, j) of the matrix circuit of the present invention
(Θ _i , φ _j )
When the desired beam direction is (θ _s , φ _s ), the transmission signal (or the reception signal) is defined as sin [θ _s ] −sin
The signal is distributed to three or more ports of the Mastox circuit according to the power density distribution and the phase distribution obtained by the Gaussian function of the complex coefficient with [θ _i ] and sin [φ _s ] −sin [φ _i ] as variables ( Or a power supply circuit for synthesizing signals from a plurality of ports).

The reason that the beam direction changes according to the position of a port to which power is supplied by a phased array antenna using a matrix circuit is that an input signal is distributed by the matrix circuit and at the same time, the output of each of the ports depends on the position of the port to which power is supplied. This is because the phase of the signal at the port rotates, causing a tilt in the phase plane. This can be considered as performing Fourier transformation in principle.

The Gaussian function exp to the aperture plane amplitude distribution was variable ^{x [- (ax) 2/} 2] and then, this secondary phase distribution exp when given [-Ibx ^2] (I is the imaginary unit, I
² = -1), and the aperture excitation distribution is exp [-(a ² + I
b) x ^2/2], and the Gaussian function of the complex coefficients by the ^{a 2 + Ib = c 2 exp} [- (cx) can be represented as a ^2/2].

The Fourier transform of this function is also Gaussian shaped complex coefficient exp [- (x / c) 2/2] become / c.

By calculating the power and the phase to each port to which power is supplied from this function and supplying power, it becomes possible to give a second-order phase distribution to the aperture surface.

Specifically, the function exp [-(x / c)
^2/2] / power density distribution K obtained by squaring the absolute value of c | exp [- (x / c) 2/2] / c | 2
(K is a standardization constant), finds the power distribution of the port to which power is supplied, and similarly weights the power density.
exp [- (x / c) 2/2] / c | exp [- (x / c)
^From the declination angle of the definite integral of 2/2] / c |, the phase distribution of the port to which power is supplied is determined.

From the above, the feeding circuit of the antenna of the present invention is
The signal fed to the matrix circuit by the
It will have a quadratic component in the mouth phase distribution. Ma
The magnitude of the secondary component of the phase distribution is represented by the complex coefficient c = Sqr
t [a^Two+ Ib] takes various values depending on the value of the constant b
It is possible. Note that the complex coefficient c = Sqrt [a ^Two
+ Ib] is the amplitude distribution of the antenna aperture (edge
(Strength of the paper).

It is to be noted that a plurality of ports used for signal power supply are preferentially used in descending order of power supply power. The beam directions corresponding to these selected ports are adjacent to each other, and if the beam directions when power is supplied by the individual ports of the matrix circuit alone are arranged in order corresponding to the port positions, a plurality of beams used for signal power supply are used. The port is a plurality of adjacent ports.

Due to the nature of the Fourier transform, the deeper the edge taper of the amplitude distribution to be obtained by the aperture plane excitation distribution, the wider the power density distribution of the power supply signal (the larger the constant a). Also, when the secondary component of the phase distribution is increased (the constant b is increased), the power density distribution of the power supply signal tends to spread. This can be understood from the fact that the value of the complex coefficient c = Sqrt [a ² + Ib] of the Gaussian function increases.

However, even when a relatively deep edge taper is provided in the aperture excitation distribution, the required spread of the power density distribution is small. (For example, even when the edge taper of the aperture excitation distribution is -20 dB, it is possible to cover up to about 99.8% if there is a width of three ports.) Further, the secondary component in the phase distribution Even if you have
The spread of the power supply signal due to the correction of the distortion of the antenna aperture is not large. (For example, when the edge taper of the aperture excitation distribution is −20 dB, and the secondary component of the phase distortion is + 72 ° at both ends of the antenna aperture, the spread of the power density distribution of the feed signal by correcting the phase distortion is about 7%. .) Note that the discussion so far basically does not depend on the matrix circuit size. Therefore, when the technology of the present invention is used, even when the matrix circuit scale is large (when the size of the array antenna is large), by using 3 or 4 ports for signal feeding per one-dimensional direction in the matrix circuit per beam, A second-order phase distribution can be given to the aperture surface, and pattern deterioration caused by antenna distortion or the like can be corrected.

[0037]

Embodiments of the present invention will be described below in detail with reference to the drawings.

The following is an N-port matrix circuit N
Direct emission (1) using a Butler matrix of ports
The present invention will be described by taking a (dimensional) linear array antenna as an example. FIG. 1 to FIG. 3 are diagrams illustrating Embodiments 1 to 3 of the present invention. In these figures, numeral 19 is an input signal, 20 is a matrix circuit, 21 is an element antenna, 2
Reference numeral 2 denotes an N-port variable power distribution / phase control circuit for controlling signal power (p) and signal phase (φ) according to the beam direction; 23, an M × N-port power distribution / phase adjustment circuit;
Represents a power combiner.

FIG. 1 shows a combination of a matrix circuit 20 and an N-port variable power distribution / phase adjustment circuit 22, which divides a signal into arbitrary power ratios, controls individual phases, and supplies the signals to the matrix circuit. Things. FIG. 3 assumes k multi-beams. The k N-port variable power distribution / phase control circuit 22 includes a power combiner (PC) 24.
Through a matrix circuit 20. FIG. 2 shows that in the case where continuous beam scanning is not required, instead of the variable power divider, M × N port power distribution /
The phase adjustment circuit 23 is used. The input signal 19 selects an input position according to the beam direction.

When beam scanning over a wide area is not required, it is not necessary to supply signals to all the N ports of the matrix circuit 20. Therefore, unused ports may be terminated. Further, the above-described matrix power supply circuit (N-port variable power distribution / phase control circuit 22, M × N-port power distribution / phase adjustment circuit 23) can be realized relatively easily by using a digital circuit such as a DSP.

Next, the arrangement of the element antenna 21 is determined by the distance dλ.
Are arranged at equal intervals to supply power to each port of the matrix circuit 20.
The distribution of the power density is determined. Output of matrix circuit 20
The phase difference between adjacent ports in force depends on the position of the input port.
Therefore, (-(N-1) / N) ^* 180 ° ~ (+ (N-
1) / N)^*Up to 180 °, (2 / N)^* 180 ° increments
Can take N values. Input ports corresponding to these
To port 1, port 2, ..., port in ascending order of output phase difference.
Port N. Generally, the directional characteristics of the element antenna 21 are
Very broad compared to the directional characteristics of the entire array antenna
When determining the beam direction, the element
There is almost no need to consider the influence of the directional characteristics of the antenna 21.
From the above, the window corresponding to the port position i for power supply is
Beam direction θ _iIs θ from the output phase difference of the matrix circuit._i=
sin^-1[− (2i−N−1) / 2Nd].

Therefore, sin [θ _i ] = − (2i−N−
1) / 2Nd. Here, when the desired beam direction is θ _s , the excitation distribution to each port of the matrix circuit 20 is obtained using the following function. Note that the variable x
In order to find the width, sin to make the width of N ports correspond to the width sqrt [2πN] of FFT (Fast Fourier Transform)
[Θ _s ] −sin [θ _i ] is multiplied by a coefficient d sqrt [2πN].

[0043] exp [- (x / c) 2/2] / c, x = d sqrt [2πN] (sin [θ s] -sin [θ i]) = sqrt [2πN] (sin [θ s] d − (N + 1) / 2N + i / N) Here, the complex coefficient c can be expressed by a relational expression of c ² = a ² + Ib, a is a parameter that defines the edge taper of the amplitude of the aperture excitation distribution, and b is the phase Distribution 2
These parameters define the following components.

From this, the individual ports of the power supply section
The power is expressed by the above function exp [-(x / c) ^Two/ 2] / c absolute
Function K | exp [-(x / c)^Two/ 2] / c
|^Two(K is a standardized constant), and the phase
Similarly, for the function exp
[-(X / c)^Two/ 2] / c | exp [-(x / c)^Two/
2] / c |. Fig. 4
Gaussian function exp [-(x / c) of prime coefficients^Two/ 2] / c and
Related to the power supplied to each port of the matrix circuit
It shows the person in charge. In FIG. 4, the complex coefficient c is c
²= A²+ 2Ib
Where a is a parameter that defines the amplitude distribution of the antenna aperture.
And b represents the second-order component of the phase distribution on the antenna aperture surface.
It is a parameter to be specified. Feeding phase φ of port i
_iIs a function similarly weighted by power density

[0045]

(Equation 1)

Is obtained from the argument of the definite integral.

FIGS. 5 and 6 show the amplitude distribution and the phase distribution of the antenna aperture when the parameter a defining the edge taper of the amplitude is fixed and the parameter b defining the secondary component of the phase distribution is changed. Each is shown. The number of ports N of the matrix circuit 20 was set to 16. Numerals 25, 26, 27, 28, and 29 in FIG. 5 indicate the values of the parameter b as 0, 0.25, 0.5,
It shows the amplitude distribution when 0.75 and 0.1 are set,
Numerals 25 ', 26', 27 ', 28', 2 in FIG.
9 'sets the value of parameter b to 0, 0.25,
The phase distribution when 0.5, 0.75, and 0.1 are set is shown. The magnitude of the quadratic component of the phase distribution corresponding to each value of b is 0 °, 36 °,
72 °, 108 ° and 144 °. The value of the parameter a is sqrt [π / N], and the corresponding value of the edge taper of the opening surface is -21.4 dB.

From FIGS. 5 and 6, it is understood that the use of the method of the present invention makes it possible to add a second-order component to the phase distribution without changing the amplitude distribution of the antenna aperture.

FIG. 7 shows an antenna pattern calculation result when a signal is fed according to the above power / phase distribution when a secondary phase distortion of + 72 ° exists at both ends of the antenna aperture. The antenna is a 16-element linear array (N = 16) with an element spacing of 0.68 wavelength, and the numerals 30, 31, and 32 in FIG.
The beam patterns are shown as °, -14.6 °, and -16.0 °. The value of the parameter a at this time is sqrt [π
/ (2N)], and the corresponding value of the edge taper of the opening surface is -10.7 dB. The number of ports used for power supply is four.

Using the conventional technique, the same conditions (16 element linear array with element spacing of 0.68 wavelength, +72 at both ends of the aperture)
° second-order phase distortion and the value of the edge taper of the opening surface are −10.
When the antenna pattern was calculated at 7 dB), the antenna pattern was greatly deformed as shown in FIG. 13, but in the antenna pattern of the present invention, the second-order distortion component of the aperture plane phase was canceled out well. It can be understood that almost the same antenna pattern as in the ideal case where there is no phase distortion in the antenna aperture surface shown in FIG. In fact, 89% to 96% of the dispersion value of the phase distortion component (second order component) in the aperture plane is eliminated. When power is supplied using three or five ports, the values are 4% to 91% and 88% to 97%, respectively. However, it can be seen that a good distortion compensation effect can be obtained.

In the case of a planar array antenna using a (two-dimensional) matrix circuit 20 having N ports in the horizontal direction and M ports in the vertical direction, the power density distribution to be supplied to each port is as follows.

The element antennas 21 are arranged at equal intervals in the horizontal and vertical directions with a distance dλ, and the beam direction corresponding to the port position (i, j) for feeding power is (θ _i , φ _j ).

[0053] desired to the beam direction (θ _s, φ _s) when a, the function representing the excitation distribution in the transverse direction f exp [- (x / c ) 2/2] / c, x = d sqrt [ 2πN] (sin [θ _s ] −sin [θ _i ]) = sqrt [2πN] (sin [θ _s ] d− (N + 1) / 2N + i / N), a function representing the excitation distribution in the vertical direction the g exp [- (y / h ) 2/2] / h, y = d sqrt [2πM] (sin [φ s] -sin [θ j]) = sqrt [2πM] (sin [φ s] d- (M + 1) / 2M + j / M). Therefore, the excitation distribution that the signal follows is obtained from the excitation distribution in each direction by fg exp [− ｛(x / c) ² +
(Y / h) is represented as ^{2/2}] / (ch} ). Here, c and h are complex coefficients defining the aperture excitation distribution,
f and g are coefficients defining the magnitude of the excitation distribution in the horizontal and vertical directions.

[0054]

As described above, according to the present invention, it is possible to add a quadratic component of an arbitrary size to the phase distribution of the excitation distribution (output of the matrix circuit) on the antenna aperture. Even when distortion is present in the antenna, it is possible to perform phase compensation and obtain a good antenna pattern. This can be realized with a small-scale control circuit, and there is no need to directly control the phase of a large number of element antennas as in the prior art, so that the adjustment of the device is simplified, and at the same time the complexity of the antenna configuration and the weight of the antenna are reduced. The increase can be kept small, which leads to cost reduction. In addition, even when a reflector and an array are combined, an array is arranged on a curved surface, and the phase of the element antenna is not directly controlled by a phase shifter or the like. It is possible to give the following distribution:

When the signal distribution (or signal synthesis) per one-dimensional direction in the matrix circuit is set to 3 or 4, the size of the signal distribution circuit (signal synthesis circuit) connected to the matrix circuit can be reduced. And lead to lower costs. Further, since signal distribution (signal synthesis) may be small, interference and loss in the signal distribution circuit (signal synthesis circuit) are reduced, and antenna performance is improved.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory view showing a first embodiment of the present invention.

FIG. 2 is a configuration explanatory view showing a second embodiment of the present invention.

FIG. 3 is a configuration explanatory view showing a third embodiment of the present invention.

FIG. 4 is a characteristic diagram illustrating a power supply signal distribution according to the embodiment of the present invention.

FIG. 5 is a characteristic diagram illustrating an amplitude distribution of an antenna aperture surface according to the embodiment of the present invention.

FIG. 6 is a characteristic diagram illustrating a phase distribution of an antenna aperture surface according to the embodiment of the present invention.

FIG. 7 is a characteristic diagram illustrating an antenna pattern according to the embodiment of the present invention.

FIG. 8 is a configuration explanatory view showing an example of a conventional power supply method for a phased array antenna.

FIG. 9 is a configuration explanatory view showing another example of a conventional power supply method for a phased array antenna.

FIG. 10 is a diagram illustrating the distribution power of a conventional phased array antenna.

FIG. 11 is a characteristic diagram illustrating an antenna pattern of a conventional phased array antenna.

FIG. 12 is a diagram illustrating a phase error caused by distortion of a conventional phased array antenna.

FIG. 13 is a characteristic diagram illustrating an antenna pattern of a conventional phased array antenna.

[Explanation of symbols]

1 Beam direction when power is supplied from port 1 of the matrix circuit 2 Beam direction when power is supplied from port 2 of the matrix circuit 3 Beam direction when power is supplied from port 3 of the matrix circuit 4 When power is supplied from port 4 of the matrix circuit Beam direction 5 Beam direction when power is supplied from port 5 of the matrix circuit 6 Input signal 7 Matrix circuit 8 Element antenna 9 Variable power distribution circuit 10 Power supply signal to port i-1 11 Power supply signal to port i 12 Power supply signal to port i + 1 Feeding signal 13-15 Calculation result of antenna pattern 16-18 Calculation result of antenna pattern 19 Input signal 20 Matrix circuit 21 Element antenna 22 N-port variable power distribution / phase control circuit 23 N × M-port power distribution / phase adjustment circuit 24 Power Combiner 25-29 Aperture amplitude distribution 25'-29 'Calculation result of aperture plane phase distribution 30-32 Calculation result of antenna pattern

Claims (3)

[Claims] 1. The beam direction depends on the position of the power supply port.
Phased array using a determined matrix circuit
In the power feeding method of the antenna, a center phase at an output of the matrix circuit is determined by a power feeding port.
And the power was supplied to the power supply port (i, j) of the matrix circuit.
When the beam direction is (θ _i, Φ_j ), Desired beam direction
(Θ_s, Φ_s), Sin [θ_s] -Sin [θ_i] And sin [φ_s]
−sin [φ_i] Is a Gaussian function of complex coefficients with variables
According to the power density distribution and phase distribution obtained by
Distributes signals to three or more feed ports of the matrix circuit
Or three or more power supply ports of the matrix circuit
A power supply method characterized in that a signal is synthesized from a signal. 2. The power supply method according to claim 1, wherein power is supplied to at least one of the power supply ports (i, j) using only three or more power supply ports. . 3. A phased array antenna using a matrix circuit whose beam direction is determined by the position of a power supply port, comprising a power supply circuit for distributing or combining signals by the power supply method according to claim 1. A phased array antenna.