JP6602681B2 - Antenna device and radar device - Google Patents

Description

  The present embodiment relates to an antenna device and a radar device.

  In a conventional radar apparatus, search and tracking of a target are performed by using a transmission beam and a reception beam as pencil beams by DBF (Digital Beam Forming) in an antenna apparatus.

DBF (Digital Beam Forming), Yoshida, "Revised Radar Technology", IEICE, pp.289-291 (1996) MIMO (Multiple Input Multiple Output), JIAN LI, PETER STOICA, ‘MIMO RADAR SIGNAL PROCESSING’, WILEY, pp. 1-5 (2009) Pulse compression, Yoshida, 'Revised radar technology', IEICE, pp.275-280 (1996) CFAR processing, Yoshida, 'Revised radar technology', IEICE, pp.87-89 (1996) Taylor distribution, Yoshida, 'Revised radar technology', IEICE, pp.134-135 (1996) Angle measurement system (monopulse), Yoshida, 'Revised radar technology', IEICE, pp. 260-264 (1996) Adaptive processing (MSN method, etc.), Kikuma, 'Adaptive signal processing with array antenna', Science and Technology Publishing, pp.67-86 (2004) STAP (Post-Doppler STAP, etc.), Richard Klemm, “Applications of Space-Time Adaptive Processing”, IEEE Radar, Sonar and Navigation series 14, p.720-724 (2004) Active Phase Array, Passive Phase Id Array, Yoshida, 'Revised Radar Technology', IEICE, pp.288-289 (1996) Space-fed array, Yoshida, 'Revised radar technology', IEICE, pp.132-134 (1996) Pattern shaping by phase, Robert C. Voges, ‘Phase Optimization of Antenna Array Gain with Constrained Amplitude Excitation’, IEEE Trans. Antennas & Propagation, AP-20, No.4, pp.432-436 (1972) Multibeam, edited by IEICE, Antenna Engineering Handbook 2nd edition, Ohmsha, pp.419-424 (2008)

  As described above, in the conventional radar apparatus, the target beam is searched and tracked by using the DBF in the antenna apparatus as the transmission beam and the reception beam, respectively, as the pencil beam. However, in this case, there is a time constraint per position, and since the number of hits is small, the SN is low, the data rate is slow, the initial detection is delayed, and there is a problem of lost tracking.

  The present embodiment has been made in view of the above problems, and an object thereof is to provide an antenna device and a radar device that can improve a data rate, speed up initial detection, and reduce tracking loss.

In order to solve the above-described problem, the antenna device according to the present embodiment performs beam synthesis on each of N (N ≧ 1) subarrays arranged one-dimensionally along the first axis (A axis). A first receiving array for obtaining signals Xan (n = 1 to N), and M (M ≧ 1) subarrays arranged one-dimensionally along a second axis (B axis) different from the first axis The SN is improved with respect to the beam output of the second receiving array that obtains the signal Xbm (m = 1 to M) by combining the beams with each of the subarrays of the first axis and the second axis . After signal processing, multiplication Xan × Xbm (n = 1 to N, m = 1 to M) is performed to generate a virtual array signal of an N × M subarray, and each virtual array signal is multiplied by a weight and added. To form a multi-beam within the specified angular range. And a receiving device.

Further, the radar device according to this embodiment includes a transmitting antenna that forms a transmission fan beam in the observation range, with the first axis N which are arranged one-dimensionally along the (A axis) (N ≧ 1) subarrays A first receiving array that obtains signals Xan (n = 1 to N) by beam combining, respectively, and M (M) arranged one-dimensionally along a second axis (B axis) different from the first axis ≧ 1) and a second receiver array to obtain a signal Xbm (m = 1~M) by each beam synthesized subarrays, the beam output of each subarray of the first axis and the second axis On the other hand, after performing signal processing for improving SN, multiplication Xan × Xbm (n = 1 to N, m = 1 to M) is performed to generate a virtual array signal of N × M subarrays, and each virtual array signal Multiply by weight and add And a receiving device that forms a multi-beam within a predetermined angle range within the observation range.

1 is a block diagram showing a schematic configuration of a radar apparatus to which an antenna apparatus according to a first embodiment is applied. The block diagram which shows the structure of the whole system | strain of the radar apparatus shown in FIG. The block diagram which shows the structure of the subarray system | strain of the receiving antenna shown in FIG. The conceptual diagram for demonstrating the receiving system by the two-dimensional virtual array of the receiving antenna shown in FIG. The figure which shows the observation coordinate system of the onboard radar apparatus provided with the two-dimensional virtual array shown in FIG. 5 is a flowchart illustrating a procedure of reception processing in the first embodiment. The conceptual diagram which shows the mode of the subarray beam formation in the observation space, and the whole beam formation in 1st Embodiment. The conceptual diagram which shows schematic structure of the radar apparatus with which the antenna apparatus which concerns on 2nd Embodiment is applied. The conceptual diagram which shows the mode of the subarray beam formation in the observation space, and the whole beam formation in 2nd Embodiment. The block diagram which shows schematic structure of the radar apparatus with which the antenna apparatus which concerns on 3rd Embodiment is applied. FIG. 11 is a block diagram illustrating a configuration of the transmission device illustrated in FIG. 10. FIG. 10 is a conceptual diagram illustrating an arrangement example of transmission apparatuses and a state in which transmission beams and reception multi-beams are formed in the third embodiment. 11 is a flowchart showing a processing flow of the radar apparatus shown in FIG. The conceptual diagram which shows the mode of the subarray beam formation in the observation space, and the whole beam formation in 3rd Embodiment. The conceptual diagram which shows the mode of the subarray beam formation in the observation space, and the whole beam formation in 4th Embodiment.

  Hereinafter, embodiments will be described with reference to the drawings. In the description of each embodiment, the same portions are denoted by the same reference numerals, and redundant description is omitted. In the following description, it is assumed that the embodiment of the antenna device is applied to a radar device.

(First embodiment) (two-dimensional DBF)
The first embodiment will be described with reference to FIGS. 1 to 6.

  FIG. 1 is a block diagram showing a configuration of a radar apparatus to which the antenna apparatus according to the first embodiment is applied. In FIG. 1, reference numeral 10 denotes a sub-array constituting the receiving antenna, and 20 denotes a signal processor that performs processing such as digitization of received signals and noise removal in units of sub-arrays. A system of A axis Nch × number of sub-array beams and B axis It is provided in a system of Mch × number of subarray beams. Each subarray beam output is sent to the virtual array converter 30 to form a multi-beam of N × Mch × number of subarray beams. The beam outputs of the multi-beams formed here are combined into a predetermined number of beams by the beam combiner 40 and sent to the signal processor 50. The signal processor 50 generates and outputs a radar signal for detecting and tracking the target from the input combined beam output.

  In the above configuration, a more specific system configuration is shown in FIG. 2, and the system configuration of each subarray is shown in FIG. First, as shown in FIG. 3, the A-axis subarray 10A includes sn antenna elements 111 to 11sn, sn amplifiers 121 to 12sn, a frequency converter 13, an AD converter 14, and a subarray beam combiner. 15. The sn antenna elements 111 to 11 sn are arranged one-dimensionally in the A-axis direction. The amplifiers 121 to 12 sn amplify the signals output from the corresponding antenna elements 111 to 11 sn with low noise. The frequency converter 13 frequency-converts the signals output from the sn amplifiers 121 to 12 sn into basebands. The AD converter 14 digitizes the signal frequency-converted to baseband to obtain a Sn channel received signal. The sub-array beam combiner 15 obtains a Bs channel multi-beam output from the digitized received signal.

  As shown in FIG. 2, the received signal having the number Bs of subarray beams obtained by the A-axis subarray 10A is frequency converted, digitized, subarray beam synthesized (fast Fourier transform (FFT), pulse compressed) by the signal processor 20A. PC) and the like) are branched and output for each beam of the sub-array and sent to the virtual array converter 30i of each Bs system. Similarly, the received signal of the number Bs of subarray beams obtained by the B-axis subarray 10B of each of the M systems is digitized by the signal processor 20B, and then is branched and output for each beam of the subarrays. It is sent to the converter 30i (i = 1 to Bs), and a multi-beam with N × Mch × number of subarray beams is formed. The beam outputs of the multi-beams formed here are combined into a predetermined number of beams Ba by the beam combiner 40i, and a radar output (Ba beam) is formed by the signal processor 50i. As a result, a Bs × Ba beam is simultaneously formed as a whole.

FIG. 4 shows an overview of a two-dimensional virtual array in the receiving antenna having the above-described configuration, and explains the principle thereof.
First, for the N columns of the A-axis array in the vertical direction, the signals of the antenna elements XA1 to XAN are subjected to frequency conversion and AD conversion. Similarly, for the horizontal B axis array M columns, the signals of the antennas XB1 to XBM are subjected to frequency conversion and AD conversion. Using the signals of both axes, a multiplication operation is performed for each element signal by generating a virtual array element to generate an N × M virtual array signal. This is formulated as follows. First, when the biaxial input signals including the observation directions (AZ, EL) are expressed as Xa and Xb, respectively, the following equations are obtained. The coordinate system is shown in FIG.

Considering the case where the separation distance between the A-axis array and the B-axis array is large, the AZ angle and the EL angle are separated by adding subscripts a and b, but if the separation distance is small, A The AZ angle and the EL angle as seen from the axis array and the B axis array are equal. The angles at this time are AZ and EL, respectively.

From the above, as the signal xin input to the phase center of the virtual plane array, the biaxial signals Xa and Xb are expressed by the following equations.

When this signal is used to multiply both vectors, which is the main point of the method of the present invention, the following equation is obtained.

Next, each element becomes the following equation.

Here, when the distance between the A-axis array and the B-axis array is small, and ka = kb, the following equation is obtained.

  This indicates that a virtual element signal is generated at the position where the position vectors of an and bm are added by multiplication.

The received beam output is obtained by multiplying the element in equation (5) by a sidelobe reduction tailor weight (see Non-Patent Document 5) or the like as a sidelobe reduction weight in beam synthesis, and thereby complexing for beam pointing direction control. After multiplying the weight, addition by DBF (Digital Beam Forming, see Non-Patent Document 1) is performed, and the following equation is obtained.

The weight Wpnm for controlling the beam direction can be expressed by the following equation.

  In order to form a multi-beam using this virtual array signal Xnm, a plurality of AZp and ELp in equation (8) may be set.

  As described above, in the present embodiment, the virtual array element signal is generated by the multiplication operation using the two-axis received signals of the A axis and the B axis. This is referred to as MIMO (Multiple Input Multiple Output, Non-Patent Document 2). ) Corresponds to a method of obtaining an N × M virtual array signal from an Nch transmission signal and an Mch reception signal. In this case, the multiplication operation is automatically performed in the case of the transmission and reception method, whereas in this method, the multiplication operation of reception × reception is performed.

Here, when considering the signal component and noise component of each element signal of the virtual array, it can be expressed by the following equation.

Therefore, the SN (signal to noise power ratio) of the virtual array element signal is given by the following equation.

  This indicates that the SN (signal-to-noise power ratio) of the virtual array element signal is square. In this case, if SN ≧ 0 dB, the SN is improved by the square, but if SN <0 dB, the SN is further reduced by the square. For this reason, it is desirable that SN ≧ 0 dB in the virtual array element.

  In order to realize this, as shown in FIG. 1, DBF (Digital Beam Forming, see Non-Patent Document 1) synthesis is performed by the subarrays 10A and 10B, and fast Fourier transform (FFT) and pulse are further performed by the signal processors 20A and 20B. After performing compression (PC) or the like (see Non-Patent Document 3) to make SN ≧ 0 dB, the virtual array converter 30 generates a virtual array signal. After the virtual array is generated, the entire beam is formed by the beam combiner 40, and signal processing such as detection processing (CFAR, see Non-Patent Document 4) is performed by the signal processor 50 to obtain a radar signal output. As this signal processing, processing such as MTI (Moving Target Indicator) for suppressing unnecessary waves such as clutter, adaptive array (see Non-Patent Document 7), STAP (Space Time Adaptive Processing, Non-Patent Document 8) and the like are added. May be.

  FIG. 2 shows the relationship between the number of sub-array beams Bs, the number of beam formation Ba in beam synthesis (40) after virtual array conversion (30), and the total number of beam formations Bs × Ba. Here, there is shown a relationship between multi-beam formation with a wide beam width of a subarray having a small antenna aperture length and multi-beam formation with a narrow beam width of an entire aperture having a large antenna aperture length.

  FIG. 3 shows a system for one subarray. Signals received by the antennas 111 to 11 sn are amplified with low noise by the amplifiers 121 to 12 sn, converted into digital signals by the AD converter 14, and converted into digital signals by the subarray beam combiner 15. Form a multi-beam.

  A processing flow of the beam forming method is shown in FIG. In multi-beam formation in sub-array and whole beam synthesis, there is a method that can form beams simultaneously by FFT etc., but here, for easy understanding, a loop is formed for each beam number and the directing direction is changed. Yes.

  First, reception by the sub-array is performed (step S11), the outputs of the sub-arrays having the initial beam numbers (corresponding to the pointing direction) are synthesized (step S12), and a sub-array beam is formed by signal processing (step S13). Here, the beam number is incremented until the beam number indicates the final value, and the directivity direction is sequentially changed (steps S14 and S15).

  When it is confirmed in step S14 that the beam number has been changed, virtual array conversion is performed (step S16), the entire beam is synthesized (step S17), and target detection is performed by signal processing (step S18). ). Here, in the target detection, it is determined whether or not the beam number has ended (step S19), and the directivity direction is sequentially changed until the beam number ends (step S20). When the beam number ends, the pointing direction at that time is set as a radar output (step S21), and a series of processing ends.

  That is, in the beam forming method, at the subarray output, as shown in FIG. 7A, the observation space is divided by the multibeams of the subarray. Furthermore, as shown in FIG. 7B, a beam having a high angular resolution is obtained by forming the entire beam by beam synthesis (40) after the virtual array signal is generated by the virtual array conversion (30). Further, Σ, ΔAZ, and ΔEL for monopal angle measurement (see Non-Patent Document 6) may be formed using signals by dividing the virtual array by aperture in the whole beam synthesis. When setting a Taylor weight with reduced side lobes (see Non-Patent Document 5) or the like, it may be set for a virtual array signal.

  After generating the virtual array element signal, the entire beam is formed by the beam combiner 40, and detection processing by signal processing (50) by CFAR (see Non-Patent Document 4) or the like is performed.

  In addition, when the data capacity of the multi-beam output from the subarray is large and the processing scale increases, the observation space may be divided and processed sequentially in time division.

  As described above, in the first embodiment, the receiving array (Xan, n = 1 to N) (A axis) including N (N ≧ 1) subarrays arranged in one dimension and an axis different from the receiving array (B axis) ) In the receiving array (Xbm, m = 1 to M) of the M (M ≧ 1) subarrays arranged in one dimension, signal processing is performed on the beam outputs of the subarrays of the A axis and the B axis. A virtual array signal of an N × M subarray is generated by multiplication of the axis subarray signal Xan × Xbm (n = 1 to N, m = 1 to M), and the element signal is multiplied by a predetermined weight and added. A multi-beam having a predetermined angle range is formed.

  That is, according to the present embodiment, the signal processing is performed using the different two-axis N-stage and M-column sub-array signals to improve SN (signal to noise power), and then the virtual surface array. N × M subarray signals can be generated to form a multi-beam.

Second Embodiment (two-dimensional DBF using an analog beam)
In the first embodiment, the case where DBF (Digital Beam Forming, Non-Patent Document 1) is used for subarray synthesis has been described. In this case, frequency conversion and AD conversion are required for each antenna element, and if the number of beams is large, the amount of data transfer increases and the hardware (HW) and processing scale also increase. In the present embodiment, as a countermeasure, a method of forming an analog beam in the subarray will be described.

  Since the whole system is the same as that of FIG. 1, the description is abbreviate | omitted. The subarray system in this embodiment is shown in FIG. In FIG. 8, signals received by the antenna elements 1111 to 111Sn,..., 11m1 to 11mSn in the subarray are amplified with low noise by amplifiers 1211 to 121Sn,. .., 16m1 to 16mSn, the phase shift amount for the beam scanning is set, and then synthesized by the analog synthesizers 171 to 17Sn, and the output number Bs0 = Ps × Sn. Needless to say, the unit of analog synthesis may be a unit obtained by dividing a plane, or may be synthesized for each column or stage. After obtaining this divided analog beam output, it is frequency converted to an intermediate frequency by frequency converters 181 to 18Bs0, converted to a digital signal by AD converters 191 to 19Bs0, DBF processed by subarray beamformer 19a, Is output.

  FIG. 9 shows how the beam is formed in the sub-array system having the above configuration. Here, for ease of understanding, the case where an analog beam is formed on the AZ plane (EL plane) will be described, but a method of dividing the observation space into P pieces in an arbitrary direction may be used.

  In the sub-array, as shown in FIG. 9A, an analog beam on the AZ plane (EL plane) is formed by the phase shifter (16), and the EL plane (AZ plane) is further generated using the analog beam output. A multi-beam is formed by the DBF.

  In order to divide the analog beam output into a plurality of parts, as shown in FIG. 8, a plurality of phase shifters (16) are used, as many analog synthesizers (17), frequency converters (18), AD, as there are phase shifters. What is necessary is just to comprise a converter (19). Alternatively, the number of phase shifters (16) may be left as they are, and a plurality of beams may be formed using a Butler matrix, a matrix feeding circuit (see Non-Patent Document 12), or the like as the analog synthesizer (17). In addition, if the observation range can be covered with a plurality of analog beams, a simple configuration such as eliminating a phase shifter may be used. Besides, the gist of the present embodiment using a combination of analog beams and DBFs. Other configurations may be possible within the scope. As shown in FIG. 8, when the Ps (Ps = 1 to P) lines are formed by the analog synthesizer 17, the number of outputs becomes Bs0 = Ps × Sn (the number of analog synthesizers). A frequency converter (18) and an AD converter (19) are provided, and the number of Bs is increased by DBF in the subarray beam former (19a). Next, signal processing (20) is performed on the multi-beam outputs # 1 to #Bs in order to improve SN.

  Next, a virtual array signal is generated for the multi-beam output of the subarray, and the entire beam is formed. As a result, as shown in FIG. 9B, it is possible to form a high resolution multi-beam (Bs × Ba) on the angle axis. At this time, in the observation space, the sub-array beam is scanned and observed simultaneously, or beam formation is performed in a time division manner, and the entire observation range is covered while processing each.

  As described above, in the radar apparatus having the above-described configuration, at least a part of the AZ axis or EL axis in the subarray is analog beam synthesis, and the observation range is divided into P pieces in each subarray, and each division range is defined as P. Signal processing is performed on the sub-array output formed by beam forming using DBF (Digital Beam Forming) as necessary, using the output of the analog beam whose direction is changed (p = 1 to P).

  That is, by forming analog beams as N-stage and M-column sub-array signals of two different axes, reducing the processing scale, and performing signal processing to improve SN (signal to noise power), An N × M subarray signal of a virtual surface array can be generated to form a multi-beam.

(Third Embodiment) (First Embodiment + Radar Device with Transmitter Added)
In the first embodiment, the receiving apparatus has been described. However, a radar apparatus can be configured by adding a transmitting apparatus. The entire system is shown in FIG. 10, and the system of the transmission apparatus 100 shown in FIG. 10 is shown in FIG.

  In FIG. 10, reference numeral 100 denotes a transmission device. The configuration of the receiving apparatus is the same as that shown in FIG.

  In FIG. 11, the transmission signal is distributed to the Mt system by the transmission distributor 105 and sent to the transmission distributors 1041 to 104Mt, and further distributed to the Nt system by the transmission distributors 1041 to 104Mt, respectively. The amount of phase shift is set to control the directing direction of the transmission beam, and after high-power amplification by the transmission amplifiers 1021 to 102NtMt, the antenna elements 1011 to 101NtMt radiate into the space. Although the arrangement of the transmission array in the transmission apparatus 100 is arbitrary, as shown in FIG. 12, if it is arranged in the space inside the reception array arranged in the L shape, the space is effectively used.

  Since the transmission device can be set independently of the reception array, the transmission array may have an arbitrary shape. In an extreme case, the antenna can be a parabolic antenna using a solidified transmitter or an electron tube transmitter.

  FIG. 13 shows a processing flow of the radar apparatus having the above configuration. In FIG. 13, there is a technique in which beam formation can be performed simultaneously by FFT or the like in multi-beam formation in subarray or whole beam synthesis. Here, for easy understanding, a loop is formed for each beam number to change the directing direction. It is described.

  First, a transmission beam is formed toward the observation space (step S31), a reception multi-beam is sequentially formed in the observation space and received for each subarray (step S32), and a combined beam for each subarray is output from the output of each subarray. Form (step S33). Here, the beam reception signal is extracted by signal processing (step S34), and the beam number is incremented until the beam number indicates the final value, and the directing direction is sequentially changed (steps S35 and S36).

  If it is confirmed in step S35 that the beam number has been changed, virtual array conversion is performed (step S37), the entire beam is synthesized (step S38), and target detection is performed by signal processing (step S39). ). Here, in the target detection, it is determined whether or not the beam number has ended (step S40), and the directing direction is sequentially changed until the beam number ends (step S41). When the beam number ends, the directivity direction at that time is set as a radar output (step S42), and a series of processing ends.

  As a beam forming method, for example, as shown in FIG. 14, there is a method of transmitting a fan beam (observation space is a transmission beam forming range) and receiving a multi-beam. In order to form a transmission fan beam, the phase of the transmission antenna is controlled (see Non-Patent Document 11). In order to form a wide fan beam, it is conceivable to use a quadratic phase distribution or a random phase on the antenna opening surface.

  The reception beam forming method is the same as that in the first embodiment, and a multi-beam in a range where a transmission beam is formed may be used. FIG. 14A shows the formation of the reception beam, and FIG. 14B shows the overall beam formation. The transmission beam covers the entire observation space or a divided range, and a subarray beam in the observation space is formed in the subarray, and after generating the virtual array, an angular axis high resolution beam is formed by the entire beam.

  In addition, when the data capacity of the multi-beam output from the subarray is large and the processing scale increases, the observation space may be divided and processed sequentially in time division.

  As described above, in this embodiment, the receiving array (Xan, n = 1 to N) (A axis) by N (N ≧ 1) subarrays arranged in one dimension and the axis (B axis) different therefrom In the receiving array (Xbm, m = 1 to M) of M (M ≧ 1) subarrays arranged in a one-dimensional manner, signal processing is performed on the beam output of each of the A-axis and B-axis subarrays. A virtual array signal of an N × M subarray is generated by multiplication of the subarray signal Xan × Xbm (n = 1 to N, m = 1 to M), and the element signal is multiplied by a predetermined weight and added. A multi-beam with an angular range of is formed, and transmission is performed by forming a beam within a predetermined angular range.

  That is, signal processing is performed using N-stage and M-column subarray signals of two different axes together with the transmission beam, thereby improving SN (signal to noise power) and then N × M of the virtual plane array. A radar apparatus that generates sub-array signals and forms a multi-beam can be configured.

(Fourth Embodiment) (Second Embodiment + Radar Device with Transmission Device Added)
In the second embodiment, the receiving apparatus has been described. However, a radar apparatus can be configured by adding a transmitting apparatus. The entire system and the transmission system are the same as those in FIGS. 10 and 11, respectively. The difference from the third embodiment is that, similarly to the second embodiment, analog beam forming is used in the reception sub-sales, and the transmission beam is formed within the formation range of the reception simultaneous multi-beam.

  FIG. 15 shows sub-array beam formation and overall beam formation within the transmission beam shape range. As can be seen from the comparison, the beam forming method is different, and as shown in FIG. 15, a transmission beam is formed in the observation space, and the reception is analog beam forming in the sub-array as in the second embodiment. Multi-beam within the transmission range. Here, a virtual array is generated using the output to form a beam with high resolution on the angle axis. The entire observation range is covered while scanning the subarray beam in the observation space and processing in time division.

  In the third and fourth embodiments, the pulse transmission radar device has been described. However, a continuous wave radar may be used. In addition, the transmission antenna in the third embodiment and the fourth embodiment is not limited to the configuration of an active phased array (see Non-Patent Document 9) in which transmission modules are arranged. For example, a space-feed type array (see Non-Patent Document 10) in which an active phased array is used as a primary radiator and a phase shifter is arranged in front of the active phased array, or a passive phased array combined with a solid-state transmitter or an electron tube (Non-Patent Document) Reference 9), a spatially fed array, a parabolic antenna, or the like may be used.

  As described above, in this embodiment, at least a part of the AZ axis or EL axis output in the sub-array is analog beam synthesis, the observation range is divided into P pieces, and each division range is set to P (p = 1 to P). ) A transmission beam is formed using the output of the analog beam whose direction is changed, and signal processing is performed on the reception output of the beam-formed subarray.

  That is, in this embodiment, the processing scale is reduced by forming analog beams as N-stage and M-column subarray signals of different two axes. Furthermore, after improving SN (signal-to-noise power) by signal processing, an N × M subarray signal of a virtual surface array is generated, a multi-beam is formed, and combined with a transmission beam, radar A device can be configured.

  In addition, the said embodiment is not limited as it is, In the implementation stage, a component can be deform | transformed and embodied in the range which does not deviate from the summary. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

DESCRIPTION OF SYMBOLS 10 ... Reception subarray, 20 ... Signal processor, 30 ... Virtual array converter, 40 ... Beam combiner, 50 ... Signal processor,
DESCRIPTION OF SYMBOLS 10A ... A-axis subarray, 10B ... B-axis subarray, 111-11 sn ... Antenna element, 121-12 sn ... Amplifier, 13 ... Frequency converter, 14 ... AD converter, 15 ... Subarray beam combiner, 20A, 20B ... Signal processing 30i ... virtual array converter, 40i ... beam combiner, 50i ... signal processor,
1111 to 111Sn, ..., 11m1 to 11mSn ... Antenna elements, 1211 to 121Sn, ..., 12m1 to 12mSn ... Amplifiers, 16, 1611 to 161Sn, ..., 16m1 to 16mSn ... Phase shifters, 17, 171 to 17Sn ... Analog Synthesizer, 18, 181-18Bs0 ... frequency converter, 19, 191-19Bs0 ... AD converter, 19a ... subarray beamformer,
DESCRIPTION OF SYMBOLS 100 ... Transmitting device, 1011 to 101NtMt ... Antenna element, 1021 to 102NtMt ... Transmission amplifier, 1031 to 103NtMt ... Transmission phase shifter, 1041 to 104Mt ... Transmission distributor, 105 ... Transmission distributor.

Claims (6)

First reception for obtaining a signal Xan (n = 1 to N) by beam-combining element outputs with N (N ≧ 1) sub-arrays arranged one-dimensionally along the first axis (A axis). An array,
Signals Xbm (m = 1 to M) are obtained by beam-combining the element outputs with M (M ≧ 1) subarrays arranged one-dimensionally along a second axis (B axis) different from the first axis. A second receiving array
Signal processing for improving SN is performed on the beam output of each sub-array of the first axis and the second axis, and then multiplication Xan × Xbm (n = 1 to N, m = 1 to M) is performed. An antenna device comprising: a receiving device that generates a virtual array signal of N × M subarrays, multiplies each virtual array signal by a weight, and adds the weights to form a multi-beam in a predetermined angle range.   Each of the first receiving array and the second receiving array is configured such that at least a part of the AZ axis or EL axis in the sub-array is analog beam synthesis, and the observation range is divided into P in each sub-array, 2. The antenna apparatus according to claim 1, wherein an output of an analog beam whose division range is changed in P (p = 1 to P) directivity directions is used as an output of the subarray.   3. The antenna apparatus according to claim 2, wherein the first receiving array and the second receiving array use the output of the analog beam, and further form a beam by DBF (Digital Beam Forming) to output the subarray. A transmission antenna that forms a transmission fan beam in the observation range;
First reception for obtaining a signal Xan (n = 1 to N) by beam-combining element outputs with N (N ≧ 1) sub-arrays arranged one-dimensionally along the first axis (A axis). An array,
Signals Xbm (m = 1 to M) are obtained by beam-combining the element outputs with M (M ≧ 1) subarrays arranged one-dimensionally along a second axis (B axis) different from the first axis. A second receiving array
Signal processing for improving SN is performed on the beam output of each sub-array of the first axis and the second axis, and then multiplication Xan × Xbm (n = 1 to N, m = 1 to M) is performed. And a receiver that generates a virtual array signal of N × M subarrays, multiplies each virtual array signal by a weight and adds the weights, and forms a multi-beam in a predetermined angular range within the observation range. apparatus.   Each of the first receiving array and the second receiving array is configured such that at least a part of the AZ axis or EL axis in the sub-array is analog beam synthesis, and the observation range is divided into P in each sub-array, The radar apparatus according to claim 4, wherein an output by an analog beam whose division range is changed in P (p = 1 to P) directivity directions is used as an output of the subarray. The radar apparatus according to claim 5, wherein the first receiving array and the second receiving array use the output of the analog beam and further form a beam by DBF (Digital Beam Forming) to output the subarray.

Images