JP5669625B2 - Aperiodic array antenna device - Google Patents

Description

  The present invention relates to an aperiodic array antenna device in which a plurality of element antennas are arranged so as not to have periodicity, and in particular, by controlling the amplitude and phase of each element antenna using individual transmission / reception modules. The present invention relates to a technique for optimizing the beam directing direction.

  Conventionally, an array antenna in which a plurality of element antennas are arrayed is often used as an antenna of a radar device or a radio wave monitoring device. This type of array antenna is required to have a larger effective radiated power in order to improve antenna performance and detect farther targets, particularly during transmission.

  The effective radiated power is defined as the product of the antenna gain and the transmission peak power, and in order to increase the transmission peak power, increase the output of the transmission module connected to each element antenna, or It is required to increase the antenna gain by increasing the aperture diameter.

Usually, when array antennas are arranged in a plane, a quadrangular arrangement or a triangular arrangement is used (see, for example, Non-Patent Document 1).
In an array antenna arranged in this way, it is known that when the element arrangement interval is increased, an unnecessary grating lobe having substantially the same gain as the main lobe is generated in a direction different from the main lobe.

Therefore, it is necessary to appropriately set the element arrangement interval d so that no grating lobe is generated.
For example, in the case of a quadrangular arrangement, it is necessary to set the element arrangement interval d as shown by the following formula (1) with respect to the light speed c, the frequency f, and the maximum scanning angle θm.

  d ≦ {1 / (1+ | sin θm |)} (c / f) (1)

  In the case of a triangular arrangement, it is necessary to set the element arrangement interval d as shown by the following formula (2).

  d ≦ {1 / cos30 ° (1+ | sin θm |)} (c / f) (2)

In addition, in the case of having a bandwidth, it is necessary to determine an element antenna interval at which no grating lobe is generated at the highest frequency. Further, as the aperture diameter increases, the number of element antennas increases, and the number of transmission / reception modules connected to the element antennas also increases.
Generally, since the transmission / reception module is expensive, it is desired to suppress the number of transmission / reception modules in the entire antenna.

When the grating lobe described above is generated, the antenna gain in a desired direction is reduced, and an incoming radio wave from a direction other than the desired directivity direction is received, and ambiguity is generated in the direction detection.
Therefore, it is desired to reduce the number of element antennas while realizing a configuration for avoiding the generation of grating lobes.

  Therefore, as a technique for reducing the number of transmission / reception modules, a method is known in which a plurality of element antennas are combined to form a subarray and a phase shifter is assigned to each subarray. In this case, a grating lobe is generally generated. To do.

Therefore, a technique using a non-periodic array antenna in which subarrays are arranged so as not to have periodicity in order to suppress grating lobes has been proposed (for example, see Non-Patent Document 2 and Non-Patent Document 3).
According to the aperiodic array antenna, it is known that the side lobe level is improved by a maximum of 8.24 [dB] as compared to the periodic array antenna.

  In addition, array antennas are often required not only to suppress grating lobes but also to reduce side lobes. In view of this, conventionally, in a periodic array antenna, a technique of providing a tapered amplitude distribution in the aperture distribution has been proposed in order to reduce the side lobe (see, for example, Non-Patent Document 4).

  Further, as an example of applying decimation to an aperiodic array antenna, a technique for optimizing decimation by numerical analysis using GA (Genetic Algorithm) in order to suppress grating lobes has been proposed (for example, non-patent) Reference 5).

Antenna Engineering Handbook, IEICE bias, H16-5-15 Kadoguchi et al .; Science theory (B), VOL. J90-B, No. 10, 2007. Kadoguchi et al .; IEICE Communication Society University, B-1-110 (2008). R. J. et al. Mailloux, Phased Array Antenna Handbook. T. T. et al. G. Spence and D.C. H. Werner, IEEE AP-S, 2006.

The conventional aperiodic array antenna apparatus is difficult to provide means for substantially optimizing the arrangement of the element antennas, and the time and cost increase for suppressing the grating lobes and reducing the side lobes. was there.
In addition, as described in Non-Patent Document 4, for example, when a tapered amplitude distribution is provided in the aperture distribution, a complicated power supply circuit or a plurality of types of transmission / reception modules are required, which increases the manufacturing cost. There was a problem.

  The present invention has been made to solve the above-described problems, and in an aperiodic array antenna apparatus in which the interval between element antennas is irregular and has no periodicity, appropriate thinning according to the arrangement of element antennas is performed. An object of the present invention is to obtain an aperiodic array antenna device that realizes suppression of grating lobes and low side lobes without incurring cost increase by setting processing (including ON / OFF processing by control). .

An aperiodic array antenna apparatus according to the present invention is individually connected to a power feeding circuit for inputting / outputting an RF signal, a plurality of transmission / reception modules connected to the power feeding circuit, and a plurality of transmission / reception modules, each of which is aperiodic. An aperiodic array antenna comprising a plurality of element antennas arranged, and each of the plurality of transmission / reception modules includes a phase shifter connected to a power feeding circuit, and a phase shifter and an individual element antenna. In a non-periodic array antenna apparatus having an intervening transmitting amplifier and receiving amplifier, as a means for thinning out a plurality of element antennas, an aperture of an aperiodic array antenna arranged aperiodically is divided into N and equally divided by line K ₁ ~K _N radially at least one element antennas each consisting each adjacent section of the dividing line the N divided regions Y ₁ to Y _N are And radial dividing means for setting the divided regions to standing, divided region _{Y i (i = 1,2, ···} , N) and the area _{S i} of the prime number of child _{I i} that exists divided region using a ratio, the element density a _i of the divided regions, a i _{= I} i _/ and element density calculating unit Ru determined by S _i, amplitude average value the average value of the amplitude of each region of the divided region Y _i When X _i is set, the ratio of the element densities a _i of the divided regions matches the ratio of the average amplitude value X _i for each divided region Y _i normalized by the average amplitude value X ₁ of the central region Y ₁ of the divided region. As described above, the number of element antennas to be thinned out in the divided area Y _i is the number of thinned elements M _i , and the number of thinned-out elements is calculated by M _i = I _i −I _i · a ₁ (X _i / X ₁ ) , when thinning the number of elements M _i, which is calculated is not an integer, 4 disposable 5 number decimation element by input M _i An integerizing means for making the number an integer, an angle direction dividing means for setting the divided area Q by equally dividing the divided area Y _i into M _i in the angular direction using the integer number of thinned elements M _i , and a divided area If there is a thinning processing means for thinning out one element antenna at random from within Q and an area in which no element antenna capable of thinning out exists in the divided area Q, the number P of areas where no element antenna is present P _i is again divided equally into P _{i in the} angular direction, and the thinning-out processing means randomly thins out one element antenna from among the divided areas Q ′ divided into P _i equally, so that the inside of the divided area Q or Q ′ In addition, the element array determination unit that repeatedly executes the processing of the thinning processing unit determines the thinned element antenna until there is no region where there is no element antenna that can be thinned.

  According to the present invention, the aperture of the non-periodic array antenna is concentrically divided into N equal parts in the distance direction, and the element density a of the divided areas is calculated such that each of the N equally divided divided areas Y has, for example, a Taylor distribution. Then, the divided area Y is equally divided into M in the angular direction by using the number of off elements M so as to coincide with the calculated element density, and one element antenna is randomly turned off from the divided area Q divided into M equal parts. Thus, by realizing the excitation amplitude distribution close to the Taylor distribution by the on / off control, the suppression of the grating lobes and the reduction of the side lobes can be realized at low cost.

It is a block diagram which shows schematic structure of the aperiodic array antenna apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the arrangement | sequence state of the element antenna in FIG. It is a flowchart which shows the arrangement | sequence determination procedure of the element antenna by Embodiment 1 of this invention. It is explanatory drawing which shows the element density calculation process in the radial direction division area by Embodiment 1 of this invention. It is explanatory drawing which shows the division process of the angle direction division area by Embodiment 1 of this invention. It is explanatory drawing which shows the OFF process of the element antenna in the division area by Embodiment 1 of this invention. It is explanatory drawing which shows the example of an arrangement | sequence of the effective element antenna after off operation (thinning-out process) by Embodiment 1 of this invention. It is explanatory drawing which shows the radiation pattern formed by the example of arrangement | sequence of FIG. It is explanatory drawing which shows the example of an arrangement | sequence of the effective element antenna after off operation (thinning-out process) by Embodiment 2 of this invention. It is explanatory drawing which shows the radiation pattern formed by the example of arrangement | sequence of FIG. It is explanatory drawing which shows the arrangement | sequence state of an element antenna at the time of using the diamond tile by Embodiment 3 of this invention. It is explanatory drawing which shows the arrangement | sequence state of an element antenna at the time of using the Penrose tile by Embodiment 3 of this invention.

Embodiment 1 FIG.
Hereinafter, the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected and demonstrated about the part which is the same or it corresponds.
1 is a block diagram showing a schematic configuration of an aperiodic array antenna apparatus according to Embodiment 1 of the present invention.

In FIG. 1, an aperiodic array antenna device 1 includes a plurality (n) of transmitting / receiving modules 2, a plurality of (# 1 to #n) element antennas 7 connected to each transmitting / receiving module 2, and an input / output connector 8. The power supply circuit 9 is connected to the input / output connector 8 and supplies power to each transmission / reception module 2.
The power feeding circuit 9 includes an arithmetic processing unit 9A for determining a substantial arrangement by ON / OFF processing of the plurality of element antennas 7, and executes a processing routine (FIG. 3) described later.

  The plurality of element antennas 7 are non-periodically arranged as will be described later, and constitute an aperiodic array antenna 10. In addition, it is assumed that the arithmetic processing unit 9A in the power feeding circuit 9 recognizes each array of the element antennas 7 in advance.

The power feeding circuit 9 performs n distribution of the transmission signal to each element antenna 7 at the time of transmission, and performs n synthesis of the reception signal from each element antenna 7 at the time of reception.
Each transmission / reception module 2 having the same configuration includes a phase shifter 3 connected to a power feeding circuit 9, a transmission amplifier 4 and a reception amplifier 5 in parallel configuration connected to the phase shifter 3, a transmission amplifier 4, and It comprises a three-terminal transmission / reception switching unit 6 inserted between the receiving amplifier 5 and the element antenna 7.

The phase shifter 3 is connected to the input terminal of the transmission amplifier 4 and is connected to the input terminal of the reception amplifier 5.
The transmission amplifier 4 is connected to the first end of the transmission / reception switching unit 6, the reception amplifier 5 is connected to the second end of the transmission / reception switching unit 6, and the third end of the transmission / reception switching unit 6 is connected to the element antenna 7. .

Next, the operation of the aperiodic array antenna apparatus 1 shown in FIG. 1 will be described.
First, at the time of transmission, an RF signal input from an external circuit (not shown) through the input / output connector 8 is distributed n through the power supply circuit 9 and supplied to the n transmission / reception modules 2.

  In each of the transmission / reception modules 2, the phase shifter 3 controls the phase so that an antenna pattern is formed in a desired direction with respect to the input RF signal, and the transmission amplifier 4 includes the phase-controlled RF signal. Amplify the signal.

The amplified RF signal is input to the element antenna 7 as a transmission signal via the transmission / reception switching unit 6.
Hereinafter, each element antenna 7 radiates the transmission signal from each transmission / reception module 2 into the air as a radio wave.

On the other hand, at the time of reception, the reception signal received by the element antenna 7 is input to the transmission / reception module 2 in the opposite direction to that at the time of transmission, and the reception amplifier 5 is connected via the transmission / reception switching unit 6 in the transmission / reception module 2. Is input. The reception signal amplified by the reception amplifier 5 is input to the power feeding circuit 9 via the phase shifter 3.
Hereinafter, the power feeding circuit 9 synthesizes the received signals from the respective transmission / reception modules 2 and outputs them to the external circuit as RF signals via the input / output connector 8.

FIG. 2 is an explanatory diagram showing a specific arrangement state of the aperiodic array antenna 10 (a plurality of element antennas 7) in FIG. 1, and the openings when all the element antennas 7 are filled in a circular shape are planar. Is shown.
In FIG. 2, a plurality (n) of element antennas 7 are aperiodically arranged by pinwheel tiles 11 and 12 to constitute an aperiodic array antenna 10.

The pinwheel tile 11 has a right-angled triangular planar shape in order to form a sub-array with several element antennas 7, and as shown in the enlarged view in FIG. Is “1: 2: √5”.
In addition, one pinwheel tile 11 is constituted by a minimum unit pinwheel tile 12 divided into five, and is non-periodically filled and arranged on the opening (circular plane).

The minimum unit pinwheel tile 12 is similar to the pinwheel tile 11, and the ratio of the lengths of the three sides is similarly “1: 2: √5”.
In the minimum unit pinwheel tile 12, for example, eight element antennas 7 are arbitrarily arranged.

The aperiodic array antenna 10 has a circular opening shape having a radius 12 times the wavelength λ of the fundamental frequency f ₀ (= 3 [GHz]), and the non-periodic array antenna 10 is non-rotated by the pin wheel tiles 12 arranged in the pin wheel tiles 11. The element antenna 7 is filled (arranged) in a periodic and fractal shape without gaps.

The type of the element antenna 7 to which the present invention can be applied is arbitrary, such as a patch, a dipole, a horn, a taper notch, a spiral, a bow tie, a log peri, a slot, or other element antennas and deformation shapes of these element antennas, All are applicable.
2 shows an example in which the number of element antennas 7 arranged in one pinwheel tile 12 is “8”. However, the number of element antennas 7 is not limited to this and is arranged in the pinwheel tile 12. The number of element antennas 7 (hereinafter referred to as “number of elements”) can be arbitrarily set.

Next, a procedure for determining the arrangement of the element antennas 7 by the arithmetic processing unit 9A will be specifically described with reference to FIGS. FIG. 3 is a flowchart showing a procedure for determining the arrangement of element antennas 7 according to the first embodiment of the present invention.
The arrangement of the element antennas 7 of the aperiodic array antenna apparatus 1 is determined by the process of FIG.

In the initial state, it is assumed that all the element antennas 7 in the aperiodic array antenna 10 are in the on state.
The array of the remaining effective element antennas 7 is determined by selectively turning off the element antennas 7 from the aperiodic array antennas 10 in which all the element antennas 7 are on.

  In FIG. 3, the arrangement determination procedure of the element antenna 7 generally comprises three stages of processing steps ST1 to ST3. In step ST1, elements in a region arbitrarily divided into N equally in the radial direction of the opening (circular arrangement region). Find the density.

In step ST2, the division number M _i for equally dividing M _i in the angular direction within the divided region Y _i divided in N in step ST1 is obtained. In step ST3, M _{i is} divided in step ST2. One element antenna 7 is turned off at random (thinning-out process) from the selected region.

  Step ST1 includes three steps ST11 to ST13 described later, step ST2 includes five steps ST21 to ST25 described later, and step ST3 includes three steps ST31 to ST33 described later.

FIG. 4 is an explanatory diagram showing element density calculation processing in the radial direction divided region in step ST1 in FIG.
FIG. 5 is an explanatory diagram showing the division processing of the angular direction division region in step ST2, and FIG. 6 is an explanatory diagram showing the off processing (thinning-out processing) of the element antennas in the division region in step ST3.

In FIG. 4, the dividing lines K _{1 to} K _N are arbitrarily divided into N equally in the radial direction of the opening to form a plurality of ring-shaped divided areas Y _{1 to} Y _N. The area of each divided area _Y 1 to Y _N, in order from the _center, is represented by S 1 to S _N.

In FIG. 5, an arbitrary Taylor distribution 25 having the center of the opening as an apex is taken as an example, and amplitudes A _{1 to} A _N for each of the divided regions Y _{1 to} Y _N in the Taylor distribution 25 and an amplitude A _{0 at the} center are obtained. Show.
5, the horizontal axis represents the respective sections of the divided regions _Y 1 to Y _N divided by the division line _K 1 ~K _N, vertical axis, the amplitude _A 0 to A _N and the amplitude average X It shows the _{1 ~X N.}
Each amplitude average value X _{1 to} X _N corresponds to the level of a black dot. For example, in the divided area Y _N , the amplitude average value X _N is obtained from the amplitudes A _{N−1 to} A _N.

FIG. 6 shows angular divided areas Q, Q ′, Q ″ (enlarged sequentially) when thinning-out processing for substantial arrangement determination of the element antennas 7 is performed.
That is, first, performs a decimation process in the divided region Y _i divided regions obtained by dividing M _i such angularly Q, when the element array is not determined, the divided region Y _i to P _i equipartition (P _i < M _i ) When the thinning process is performed in the divided area Q ′ and the element arrangement is not determined, the divided area Y _i is divided into P _i ′ equally divided (P _i ′ <P _i ) in the divided area Q ″. A state in which thinning processing is performed is shown.

In FIG. 6, the first divided region Q with respect to the divided region Y _i has an angle range from the opening center of 360 / M _i [°] (i = 1, 2,..., N), and then P _i The equally divided area Q ′ has an angular range from the opening center of 360 / P _i [°], and P _i ′ has an equally divided area Q ″ having an angular range from the opening center of 360 / P _i. '[°].

In FIG. 3, first, in step ST11 in step ST1, as shown in FIG. 4, the opening is divided into N equal parts in the radial direction by concentric dividing lines K _{1 to} K _N , and dividing lines K _{1 to} K are divided. Divided regions Y _{1 to} Y _{N that} are arbitrarily divided into _N by _N are formed.

Subsequently, in step ST12, it is determined whether or not the element antenna 7 exists in the divided area Y _i (i = 1, 2,..., N), and the element antenna 7 exists in the divided area Y _i . When it is determined that it does not exist (that is, NO), the process returns to step ST11, and when it is determined that the element antenna 7 exists (that is, YES), the process proceeds to step ST13.
Note that at the time of the last re-division after returning to step ST11, the division area Y _i is enlarged and set with an arbitrary division number N smaller than the previous value.

In step ST13, as shown in the following equation (3), divided region Y _i the number of antenna elements 7 are present in each I _{i (hereinafter} referred to as "number of elements I _i") and each of the divided region Y _i of Using the area S _i , each element density a _i in the divided region Y _i is obtained.

a _i = I _i / S _i (3)

Then, the process proceeds to step ST2, the divided region Y _i in off at (decimation process) is the number M _{i (hereinafter,} referred to as "off-the number of elements M _i") of the antenna elements 7 is calculated.
First, in step ST21 in step ST2, the average amplitude value X _i (see FIG. 5) of each divided region Y _i is obtained.

Subsequently, in step ST22, each of the amplitude average values X _i obtained in step ST21 is normalized by the amplitude average value X ₁ of the central divided region Y ₁ and the element density a ₁ of the central region Y ₁ is determined. A value Z _i (i = 1, 2,..., N) multiplied by is obtained as in the following equation (4).

Z _i = a ₁ (X _i / X ₁ ) (4)

Further, in step ST23, off (thinning-out processing) is performed from among the number of elements I _i from Z _i obtained by Expression (4) and the number of elements I _i arranged in the divided region Y _i . The number of elements M _i is obtained as in the following formula (5).

M _i = I _i −I _i · Z _i
= I _i −I _i · a ₁ (X _i / X ₁ ) (5)

Subsequently, in step ST24, it is determined whether or not the number of off elements M _i obtained by Expression (4) is an integer, and it is determined that the number of off elements M _i is an integer (that is, YES). In step ST3, when it is determined that the number of off elements M _i is not an integer (ie, NO), a rounding off process is performed to convert it into an integer (step ST25). The process proceeds to (Step ST3).

First, in step ST31 in step ST3, in order to perform the thinning process evenly from within the entire region, the entire (360 °) is divided for each divided region Y _i using the number of off elements M _i obtained in step ST2. angularly divided _{M i,} etc., as shown in FIG. 6, sets the divided regions Q (angular range _{360 / M i [°])} .
Subsequently, in step ST32, one element antenna 7 is randomly turned off from within the divided region Q to perform a thinning process.

  Next, in step ST33, it is determined whether or not one or more element antennas 7 are present in all the divided areas Q after the thinning process, and if one or more element antennas 7 are present (that is, YES). If it is determined, it is assumed that the off operation of step ST32 is possible (the arrangement of the element antennas 7 is determined), and the processing routine of FIG.

  On the other hand, when it is determined in step ST33 that the element antenna 7 does not exist in the divided region Q (that is, NO), the off operation of step ST32 is impossible (the arrangement of the element antennas 7 is not determined). Therefore, the process returns to step ST32 to perform the thinning process again.

During re-execution of step ST32, there is no element antennas 7 (i.e., NO) divides P _i such an angular direction according to the number P _i of the determined area and, P _i such divided divided regions Q One element antenna 7 is randomly turned off from the element antennas 7 existing within the range '(angle range 360 / P _i [°] from the opening center)'. Thereby, the uniformity of the thinning process is maintained.

  Thereafter, in step ST <b> 33, the above process is repeated until the region where it is determined that the element antenna 7 does not exist (that is, NO) is eliminated, and the final arrangement of the element antennas 7 is determined.

FIG. 7 is an explanatory diagram showing an example of the arrangement of the effective element antennas 7 after the off operation (thinning process) is performed according to the procedure of FIG. 3, and shows the openings of the aperiodic array antenna 10 in plan view. .
In FIG. 7, as an example, the division number N in the radial direction is “12”, and the number n of the element antennas 7 of the aperiodic array antenna 10 (see FIG. 2) in which all the element antennas 7 are on is “1400”. It shows the case.

Further, the Taylor distribution 25 (see FIG. 5) for determining the number n of the element antennas 7 is a “circular Taylor distribution” (side lobe number = 4) with a side lobe level of −25 [dB] as shown in FIG. It is assumed that the arrangement of the element antennas 7 is determined by turning off the element antennas 7 according to the operation procedure.
In FIG. 7, the array of effective element antennas 7 is non-periodically distributed, and is distributed so that the element density is high in the central part of the opening and the element density is low in the outer peripheral part.

FIG. 8 is an explanatory diagram showing an analysis value of the radiation pattern by the arrangement of the element antennas 7 shown in FIG.
In FIG. 8, the analyzed fundamental frequency f ₀ is 3 [GHz], and the radiation pattern is a result of analysis with the fundamental frequency f ₀ and a frequency 2f _{0 that} is twice the fundamental frequency.
As can be seen from the radiation pattern of FIG. 8, a low sidelobe level of about −30 [dB] can be obtained at the cut surface.
According to the aperiodic array antenna apparatus 1 according to Embodiment 1 (FIGS. 1 to 7) of the present invention, it can be seen that an element arrangement having the performance of FIG. 8 can be realized.

As described above, the aperiodic array antenna device 1 according to the first embodiment (FIGS. 1 to 8) of the present invention includes a feed circuit 9 to which an RF signal is input and output, and a plurality of feed circuits 9 connected to the feed circuit 9. The transmitter / receiver module 2 and an aperiodic array antenna 10 that is individually connected to the plurality of transmitter / receiver modules 2 and each includes a plurality of element antennas 7 arranged aperiodically are configured.
Each of the plurality of transmission / reception modules 2 includes a phase shifter 3 connected to a power feeding circuit 9, a transmission amplifier 4 and a reception amplifier 5 interposed between the phase shifter 3 and the individual element antennas 7, It has.
In addition, the power feeding circuit 9 includes an arithmetic processing unit 9 </ b> A for determining a substantial arrangement by on / off processing of the plurality of element antennas 7.

The arithmetic processing unit 9A equally divides the opening of the non-periodic array antenna 10 in the radial direction by _N dividing lines K _{1 to} K _N , so that N divided regions Y ₁ to Y composed of adjacent sections of the dividing lines are obtained. each of Y _N and a radial dividing means for setting the divided regions _Y 1 to Y _N such that at least one element antenna is present (step ST11, ST12).

Further, the arithmetic processing unit 9A uses the ratio of the number of elements I _i existing in the divided region Y _i (i = 1, 2,..., N) and the area S _i of the divided region to calculate the elements in the divided region. An element density calculating means (step ST13) for obtaining the density a _i by a _i = I _i / S _i (formula (3)) is provided.

In addition, the arithmetic processing unit 9A makes the ratio of the element density a _i of the divided areas coincide with the ratio of the average amplitude value X _i for each divided area normalized by the average amplitude value X ₁ of the central area of the divided area. , Where the number of element antennas turned off in the divided region Y _i is the number of off elements M _i , and M _i = I _i −I _i · a ₁ (X _i / X ₁ ) (Expression (5)) number calculating means (step ST2, ST21~ST23) and, if the calculated off element number _{M i} is not an integer, integer unit for the off element number _{M i} to an integer by 4 discard 5 oN (step ST25) It is equipped with.

Further, the arithmetic processing unit 9A uses angle direction dividing means (step ST31) that sets the divided region Q by dividing the divided region Y _i into M _{i and the} like in the angular direction by using the integer number of OFF elements M _i. And a thinning processing means (step ST32) for randomly turning off one element antenna from within the divided region Q.

Further, operation processing portion 9A, in the divided region Q, if there is a region where no antenna elements capable off operation, P again angular direction with the number P _i region there is no antenna element _i is equally divided by thinning processing means (step ST32), 'one element antennas randomly off operation from the divided regions Q or Q' P _i such divided divided regions Q in, allows off operation There is provided an element arrangement determining means (step ST33) for repeatedly executing the processing of the thinning processing means until there is no area where no element antenna exists.

  In this way, by suppressing the grating lobes and performing the on / off operation (decimation processing) with the excitation amplitudes of all the element antennas 7 being the same, it is possible to add a density taper to the element arrangement. Lobeing can be realized and the number of element antennas 7 that are substantially effective can be reduced.

  That is, by setting the excitation amplitude distribution by appropriate decimation processing according to the arrangement of the element antennas 7, even in a high-power active phased array radar or the like in which a grating lobe or a high level side lobe in the paraxial is a problem. Therefore, suppression of grating lobes and reduction of side lobes can be realized without incurring cost increases.

In FIG. 1, the arithmetic processing unit 9A is provided in the power feeding circuit 9 as means for determining the elements to be thinned out. However, the present invention is not limited to this, and the arithmetic processing unit 9A is provided outside the power feeding circuit 9. It may be calculated offline.
In this case, the on / off control of the element antenna is not necessary, and the element antenna at the position of the off control calculated in advance can be removed. Therefore, the grating lobe can be suppressed and the side lobe can be suppressed while reducing the cost and weight. Can be realized.

Embodiment 2. FIG.
In the first embodiment (FIGS. 1 to 8), the setting of the circular Taylor distribution with the side lobe level of −25 [dB] divided into 12 concentric circles has been described. The division number M _i in the angular direction can be variably set according to a desired side lobe level in the Taylor distribution.
Although an example of a circular opening is shown here, the opening shape is not limited to this, and an arbitrary opening shape such as a rectangular opening, an elliptical opening, or a polygonal opening may be used.

FIG. 9 is an explanatory diagram showing an example of the element arrangement turned off after the thinning-out process (FIG. 3) according to the second embodiment of the present invention.
In FIG. 9, the division number N in the radial direction is set to “6”, the number of elements n of the aperiodic array antenna 10 before the element antenna 7 is turned off (decimation processing) is set to “1400”, and the number of element antennas 7 is set. The tailor distribution for determining the “circular Taylor distribution” with a side lobe level of −35 [dB] is the same as described above.

FIG. 10 is an explanatory diagram showing an analysis value of the radiation pattern by the element arrangement of FIG.
In FIG. 10, the analyzed fundamental frequency f ₀ is 3 [GHz], and the radiation pattern shows the result of analysis at the fundamental frequency f ₀ and the frequency 2f ₀ which is twice the fundamental frequency.

As can be seen from FIG. 10, a low side lobe level of about −30 [dB] can be obtained on the cut surface, and it can be seen that an element arrangement having the same performance as described above can be realized.
Further, as is clear from FIG. 9, in this case, the number of effective element antennas 7 can be substantially reduced as compared with the above (FIG. 7), so that power consumption can be reduced.

Embodiment 3 FIG.
In the first embodiment (FIG. 2), the off operation (thinning processing) is performed on the aperiodic array antenna 10 arranged using the pinwheel tiles 11 and 12, but other tiles are used. You may apply to an aperiodic array antenna.

  For example, the off operation (thinning-out process) is performed on the non-periodic array antennas 10A and 10B using the diamond tile 13 as shown in FIG. 11 or the Penrose tile 14 as shown in FIG. Needless to say, the present invention is applicable and has the same effect.

  FIG. 11 is an explanatory diagram showing an aperiodic array antenna 10A in which diamond tiles 13 are arranged aperiodically, and FIG. 12 is an explanatory diagram showing an aperiodic array antenna 10B in which penrose tiles 14 are arranged aperiodically.

  In the first and second embodiments, the case where the Taylor distribution 25 is applied has been described as an example. However, the present invention is not limited to this, and the grating lobe can be applied even when any other distribution is applied. Needless to say, it can be used in a high-power active phased array radar or the like in which high-level side lobes in the paraxial are problematic, and has the same effects as described above.

DESCRIPTION OF SYMBOLS 1 Aperiodic array antenna apparatus, 2 Transmission / reception module, 3 Phase shifter, 4 Transmission amplifier, 5 Reception amplifier, 7 element antenna, 9A arithmetic processing part, 9 Feeding circuit 10, 10A, 10B Aperiodic array antenna, 11 , 12 pinwheel tile, 13 diamond tile, 14 penrose tile, 25 Taylor distribution, a _i element density, number of elements in I _i divided region, K _i , K _{1 to} K _N dividing line, number of M _i off elements (divided) number), N number of _{divisions, Q, Q ', Q "} , Y i, Y 1 ~Y N divided regions, _{S i} area, step ST11, ST12 radial dividing means, ST13 element density calculating unit, ST21～ST23 off element number calculating means, ST25 integer unit, ST31 angular dividing means, ST32 decimation process means, ST33 element sequencing _means, X _i, X 1 _{~X N} Average width value, _{Y 1} central region.

Claims (3)

A power supply circuit for inputting and outputting RF signals;
A plurality of transmission / reception modules connected to the power supply circuit;
An aperiodic array antenna that is individually connected to the plurality of transmission / reception modules and is composed of a plurality of element antennas each aperiodically arranged;
Each of the plurality of transmission / reception modules is
A phase shifter connected to the feeder circuit;
A transmitting amplifier and a receiving amplifier interposed between the phase shifter and the individual element antenna;
In an aperiodic array antenna device comprising:
As a means to thin out multiple element antennas,
The apertures of the non-periodic array antennas arranged aperiodically are equally divided in the radial direction by _N division lines K _{1 to} K _{N, and N} division regions Y each including an adjacent section of the division lines are obtained. _{1 to} Y _N , radial dividing means for setting the divided regions such that at least one element antenna exists in each of
Using the ratio of the number of elements I _i existing in the divided region Y _i (i = 1, 2,..., N) and the area S _i of the divided region, the element density a _i of the divided region is The following formula,
a _i = I _i / S _i
Element density calculation means obtained by:
When the average amplitude value in each of the divided regions Y _i is defined as the average amplitude value X _i , the ratio of the element densities a _{i in} the divided regions is the average amplitude value X in the central region Y ₁ of the divided region. ₁ to match the normalized divided region Y _i for each ratio of the average amplitude value X _i in, the number of antenna elements to be thinned in the divided region Y _i, as thinning the number of elements M _i, the following equation,
M _i = I _i −I _i · a ₁ (X _i / X ₁ )
A decimation element number calculating means obtained by:
If the calculated number of thinned elements M _i is not an integer, an integerizing means for rounding off to the number M _i of thinned elements M _i ,
Using integer been thinned element number M _i, the angular orientation dividing means for setting the divided region Q the divided regions Y _i in the angular direction by dividing M _i, etc.,
Thinning processing means for thinning out one element antenna at random from within the divided region Q;
If there is a region where there is no element antenna that can be thinned out in the divided region Q, the number P _i of the regions where no element antenna is present is used to divide P _i equally in the angular direction and perform the thinning process. By means of this, one element antenna is randomly thinned out of the divided areas Q ′ divided equally into P _i , and there is no area in which no element antenna capable of thinning operation exists in the divided area Q or Q ′. Until the element arrangement determining means for repeatedly executing the processing of the thinning processing means,
An aperiodic array antenna apparatus characterized by determining a thinned element antenna. A power supply circuit for inputting and outputting RF signals;
A plurality of transmission / reception modules connected to the power supply circuit;
An aperiodic array antenna that is individually connected to the plurality of transmission / reception modules and is composed of a plurality of element antennas each aperiodically arranged;
Each of the plurality of transmission / reception modules is
A phase shifter connected to the feeder circuit;
A transmitting amplifier and a receiving amplifier interposed between the phase shifter and the individual element antenna;
In an aperiodic array antenna device comprising:
The power supply circuit includes an arithmetic processing unit for determining a substantial arrangement by on / off processing of the plurality of element antennas,
The arithmetic processing unit includes:
The apertures of the non-periodic array antennas arranged aperiodically are equally divided in the radial direction by _N division lines K _{1 to} K _{N, and N} division regions Y each including an adjacent section of the division lines are obtained. _{1 to} Y _N , radial dividing means for setting the divided regions such that at least one element antenna exists in each of
Using the ratio of the number of elements I _i existing in the divided region Y _i (i = 1, 2,..., N) and the area S _i of the divided region, the element density a _i of the divided region is The following formula,
a _i = I _i / S _i
Element density calculation means obtained by:
When the average amplitude value in each of the divided regions Y _i is defined as the average amplitude value X _i , the ratio of the element densities a _{i in} the divided regions is the average amplitude value X in the central region Y ₁ of the divided region. ₁ to match the normalized divided region Y _i for each ratio of the average amplitude value X _i in, the number of antenna elements to be turned off in the divided region Y _i, as an off number of elements M _i, the following equation,
M _i = I _i −I _i · a ₁ (X _i / X ₁ )
Off element number calculating means obtained by
If the calculated number of off elements M _i is not an integer, the rounding means rounds off the number of off elements M _i to an integer;
Angular direction dividing means for setting the divided region Q by dividing the divided region Y _i equally into M _i in the angular direction by using the integer number of off elements M _i ;
Thinning processing means for randomly turning off one element antenna from within the divided region Q;
If there is a region where there is no element antenna that can be turned off in the divided region Q, the number P _i of the regions where no element antenna is present is again used to divide P _i equally in the angular direction, and the thinning process is performed. By means of the means, one element antenna is randomly turned off from the divided area Q ′ divided into P _{i and the} like, and there is no area in the divided area Q or Q ′ where there is no element antenna that can be turned off. Until now, element arrangement determining means for repeatedly executing the processing of the thinning processing means,
A non-periodic array antenna apparatus comprising:   The non-periodic array antenna according to claim 1 or 2, wherein the plurality of element antennas are non-periodically arranged using any one of a pinwheel tile, a diamond tile, and a Penrose tile. apparatus.

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