JP6532305B2 - Antenna device and radar device - Google Patents

Description

  The present invention relates to an antenna device applicable to a radar device that performs multi-beam search using digital beam forming (DBF).

  A system that applies an array antenna and forms multiple beams using a DBF to search for targets has been considered conventionally. Patent Document 1 discloses a faced array radar in which an antenna for transmission and an antenna for reception are separately configured, a transmission system is a nondirectional antenna, and a reception system is an array antenna. In the faced array radar described in Patent Document 1, a system in which a plurality of pencil beams are arrayed to form a multi-beam, and a single pencil beam is scanned within the coverage to search for a target in order to cover a wide coverage. Search time can be reduced more than that.

  Further, Patent Document 2 describes a radar apparatus in which a transmission antenna is shared with a reception array antenna and a transmission pattern is formed into a pencil beam.

JP, 2000-171544, A JP 11-142511 A

  In the invention described in Patent Document 1, since radio waves are transmitted using a nondirectional antenna, the transmission pattern has a low gain, and when the transmission power is the same, the target is reached compared to using a directional antenna. The problem is that you can not get a long detection distance.

  On the other hand, in the invention described in Patent Document 2, since the transmission pattern is formed into a pencil beam, the gain is high compared to the invention described in Patent Document 1, and high performance can be realized. However, in order to realize a search range equivalent to the invention described in Patent Document 1, it is necessary to electronically scan the pencil beam, and there is a problem that the search time becomes long.

  The present invention has been made in view of the above, and it is an object of the present invention to obtain an antenna device capable of achieving both shortening of a search time for a target and high performance of the device.

In order to solve the problems described above and to achieve the object, an antenna device according to the present invention includes: a plurality of element antennas for both transmission and reception; a transmitting and receiving module connected to the element antennas and transmitting and receiving signals via the element antennas; Equipped with In addition, the transmit / receive modules combine signals received by each of the transmit and receive modules in units of subarrays, and a distribution circuit for distributing the transmit signals generated by the transmitter to each of the transmit and receive modules, and time-averaged received signals combined in units of subarrays. And a digital beam forming unit that performs arithmetic processing on the time-averaged received signal to form a received multi-beam. Furthermore, the control unit is configured to control each of the transmission / reception modules, and switch the excitation phase of the signal transmitted from each of the plurality of element antennas between one of the two different phases and the other every time a specified time elapses. . The control unit divides the plurality of element antennas into a plurality of element antenna groups based on the distance from the center of the antenna aperture formed by the plurality of element antennas, and transmits signals from each of the element antennas belonging to the same group. Each of the transmitting and receiving modules is controlled so that the excitation phase is the same.

  According to the present invention, it is possible to realize an antenna device capable of achieving both shortening of a search time for a target and high performance of the device.

A diagram showing a configuration example of an antenna device Diagram showing an example of transmit beam and receive beam Diagram showing an example of correspondence between excitation phase and excitation amplitude Diagram showing an example of excitation amplitude distribution and excitation phase distribution for realizing a broad beam A diagram showing an example of excitation phase distribution set by excitation times T1 and T2 The figure which shows an example of the transmission beam which the antenna apparatus concerning embodiment concerns, and the transmission beam formed with the conventional antenna apparatus. Diagram showing the operation of a conventional antenna device The figure which shows an example of a transmission beam at the time of fixing an excitation phase and widening the beam width of a transmission beam

  Hereinafter, an antenna device and a radar device according to an embodiment of the present invention will be described in detail based on the drawings. The present invention is not limited by the embodiment.

Embodiment.
FIG. 1 is a view showing a configuration example of an antenna device according to an embodiment of the present invention. The antenna device according to the present embodiment includes a 1 _m from the plurality of element antennas 1 ₁ duplexer transmits a signal toward a target from the respective antenna elements, for receiving a signal reflected by a target. m is an integer of 2 or more, and the element antennas ₁₁ to 1 _m form an array antenna. Further, 1 _m from the antenna element 1 ₁ is divided into a plurality of groups, each element antenna of the same group forms a sub-array. The antenna apparatus according to the present embodiment can be applied to a digital beam forming (DBF) radar apparatus that performs multi-beam search using digital beam forming.

The antenna device according to the present embodiment is connected from the element antenna 1 ₁ 1 _m and one-to-one, and 2 _m of a plurality of transceiver modules 2 ₁ performs transmission processing and reception processing of signals, the transceiver module 2 the received signal output from the ₁ from each of the 2 _m as well as synthesized in subarrays units, and combining and distributing circuit 3 for distributing a transmission signal to 2 _m from the transceiver module 2 _1, generates a signal to be transmitted toward a target It comprises a transmitter 4, the reflected wave, i.e., sent by 1 _m from the antenna elements 1 _1, and 5 _n from a plurality of receivers 5 ₁ to receive the reflected signal via combining the distribution circuit 3 at a target, a. n is an integer of 2 or more and m or less and indicates the number of subarrays. 2 _m from the transceiver module 2 ₁ is configured to include an amplifier, phase shifter and the like.

The antenna device according to the present embodiment is connected from the receiver 5 ₁ 5 _n one-to-one, from a plurality of time averaging the output signal from the receiver connected time averaging processing part 21 ₁ 21 _n and the time for switching the excitation phase of a signal transmitted from each of 1 _m from the antenna elements 1 _1, i.e. the excitation time setting to set the excitation time are each set time of the plurality of excitation phases different to set exclusively The reception signal is analyzed by multiplying the received signal by weight data which is an excitation coefficient, and adding the received signal after multiplication by the excitation coefficient to form a reception multi-beam; It comprises a signal processing unit 7 for performing processing such as detecting a target, a control unit 8 for controlling the transceiver module 2 ₁ 2 _m and combining the distribution circuit 3, a.

Hereinafter referred to as array antenna formed by 1 _m from the antenna element 1 ₁ and the antenna aperture 10. In the present embodiment, and the antenna aperture 10 assumes a uniform amplitude distribution, the main function of the control unit 8 controls the phase shifter which is incorporated in each of the 2 _m from the transceiver module 2 ₁ Do.

Time averaging processor 21 ₁ from 21 _n and the excitation time setting unit 22 is provided in order to use the temporal modulation array technology done by setting the phase distribution in a conjugate relationship. Here, the outline of the time modulation array technology will be described below.

  The time modulation array technology uses the concept of time weight as described in Japanese Patent Application Laid-Open No. 2013-219742 and the like. Specifically, by setting different excitation phases depending on time and performing time averaging, that is, time integration of the transmitted or received signals, the same radiation pattern is formed equivalently as when the desired amplitude distribution is set on the antenna aperture. Technology. As different excitation phases, excitation phases of two states in a conjugate relationship in which the mirror image generation period on the frequency axis can be the widest are used. Then, two states are repeatedly set on the time axis, that is, transmission or reception is performed while switching the two states in time division.

  Next, the operation of the antenna device according to the present embodiment will be described. First, the operation of the transmission system will be described.

When the antenna apparatus transmits a signal toward the target to be searched, the excitation time setting unit 22 sets excitation times of a plurality of different excitation phases that can be switched in a time division manner in the control unit 8, and The processing units 21 ₁ to 21 _n are notified. That is, the excitation time setting unit 22 sets the time to continue the each of the plurality of excitation phase to the control unit 8, also notifies this from the time average processing unit 21 ₁ to 21 _n. The excitation time may be all different for each excitation phase or may be the same. Control unit 8 in accordance with excitation time set by the excitation time setting unit 22, controls the 2 _m from the synthesis distributing circuit 3 and the transceiver module 2 _1. Time averaging processor 21 ₁ from 21 _n in accordance with the notified excited time from the excitation time setting unit 22 averages the digital reception signal output from the 5 _n from the receiver 5 ₁ time.

Specifically, in the antenna device, at a certain excitation time T1, the transmission signal emitted from the transmitter 4 reaches the combining and distributing circuit 3, and the transmission system distributing circuit in the combining and distributing circuit 3 according to the control signal from the control unit 8. It is selected and transmitted signal from the transceiver module 2 ₁ to 2 _m is distributed through the selected circuit. 2 _m from the transceiver module 2 _1, in accordance with control signals from the control unit 8, selects a transmission circuit, the transmission signal from the combining and distributing circuit 3 is inputted, the phase of the input transmission signal, a desired excitation amplitude It sets and outputs to the excitation phase P1 which is one of two excitation phases, ie, two excitation phases in conjugate relation, for implement | achieving distribution. Transmission signal whose phase is set to the excitation phase P1 from the transceiver module 2 ₁ by 2 _m reaches the antenna elements 1 ₁ to 1 _m, after being emitted by 1 _m from the antenna elements 1 _1, is synthesized in space Ru. Thereby, the transmission pattern at the excitation time T1 is formed.

Also, at excitation time T2 after the excitation time T1 has elapsed, the transmission signal emitted from the transmitter 4 reaches the combining and distributing circuit 3, and the transmission system distribution circuit in the combining and distributing circuit 3 according to the control signal from the control unit 8. It is selected and transmitted signal from the transceiver module 2 ₁ to 2 _m is distributed through the selected circuit. 2 _m from the transceiver module 2 ₁ In accordance with the control signal from the control unit 8, selects a transmission circuit, the transmission signal from the combining and distributing circuit 3 is input, sets the phase of the input transmission signal to the excitation phase P2 Output. Transmission signal whose phase is set to the excitation phase P2 from the transceiver module 2 ₁ by 2 _m reaches the antenna elements 1 ₁ to 1 _m, after being emitted by 1 _m from the antenna elements 1 _1, is synthesized in space Ru. Thereby, the transmission pattern at the excitation time T2 is formed.

2 _m next excitation time T1, from the transceiver module 2 ₁ After excitation time T2 has elapsed, in accordance with a control signal from the control unit 8, the transmitted signal from the combining and distributing circuit 3 is input, the input transmission signal The phase is set to the excitation phase P1 and output. In the same manner, 2 _m from the transceiver module 2 _1, the phase of the transmission signal in the excitation time T2 after the excitation time T1 has elapsed is set to the excitation phase P2, after the excitation time T2 has elapsed excitation time T1 Then, the phase of the transmission signal is set to the excitation phase P1.

Thus, the control unit 8, the phase of the excitation time T1 the transmission signal to control the 2 _m from the transceiver module 2 ₁ so that the excitation phase P1, the phase of the transmitted signal at the excitation time T2 is the excitation phase P2 controlling the 2 _m from the transceiver module 2 ₁ as.

  According to the time modulation array technology, a transmission pattern of a desired beam width is formed by time averaging the transmission pattern at the excitation time T1 and the transmission pattern at the excitation time T2. This is confirmed by the transmission / reception product pattern obtained through the stage of arithmetic processing after the reception signal reaches the DBF unit 6 via the time averaging processing unit 21 in the antenna device shown in FIG. However, here, for the convenience of explanation, when the signal is radiated at the excitation time T2, the transmission pattern at the excitation time T1 and the transmission pattern at time after the transmission pattern at the excitation time T2 are averaged are formed. Shall be The transmission / reception product pattern is a pattern obtained by taking the product of the transmission pattern and the reception pattern.

  The broad beam of the transmission wave is as shown in FIG. In FIG. 2, only the main beam is shown, and the side lobes are omitted. FIG. 2A shows the transmission broad beam 25 in the case where the excitation phase distribution on the antenna aperture 10 is cophased in the front direction of the antenna aperture 10. FIG. 2B shows the receiving beam in the antenna device of the present embodiment, and the receiving beam is a multi-beam in which pencil beams 12 to 18 are simultaneously formed. The transmit beam in a conventional radar system that uses DBF to form receive multi-beams is a single pencil beam as described above and requires electronic scanning of the beam to ensure a search coverage. On the other hand, in the antenna apparatus of this embodiment, since the width of the transmission beam is expanded by the time modulation array technology, when the width of the transmission beam covers the search coverage area, it is within the search coverage area. There is no need to scan the beam electronically. Also, even if electronic scanning is required within the search area, the difference between the width required for the electronic scan, ie, the width of the transmitting beam and the area covered by the search, is smaller than that when using a pencil beam. Therefore, according to the antenna device of the present embodiment, the search time can be shortened.

Here, a method of setting the excitation phase distribution to obtain a desired broad beam will be described. Let excitation phases in a conjugate relationship be φ1 and φ2. As a result of time averaging, the relative value P of the desired excitation amplitude at each element antenna can be expressed by the following equation (1).
P = 20 log 10 (cos φ) [dB], 0 ≦ φ ≦ 90 [deg] (1)

It will become FIG. 3 if above Formula (1) is graphed. For example, when the excitation phase of a certain element antenna 1 _k (k is 1 to m) is φ1 = 60 ° and φ2 = −60 °, the equivalent excitation amplitude is P = −6 dB. This is a relative value to the excitation amplitude maximum value in the antenna aperture 10. In other words, if the desired excitation amplitude value is relatively determined to be -6 dB, the excitation phase to realize it is obtained as φ1 = 60 ° and φ2 = −60 °. That is, if the excitation amplitude for obtaining a broad beam is determined, the excitation phase is also determined according to equation (1).

  As an example, in the case of a small aperture array antenna, the case of performing broadening by time modulation array technology will be described. Here, the condition of the broad beam is at least four times the beam width of the pencil beam obtained when the uniform excitation distribution is given by the small aperture array antenna.

  FIG. 4 (a) shows a desired excitation amplitude distribution for obtaining a broad beam having a width four times the beam width of the pencil beam, and FIG. 4 (b) shows a desired for obtaining this broad beam. Excitation phase distribution. In FIG. 4A, the horizontal axis represents the distance R from the center of the antenna opening 10, and the vertical axis represents the circumference of each area when the antenna opening 10 is divided into four areas according to the distance from the center to the end. Amplitude average P in the direction. The distance R is normalized by the distance of the outermost region, that is, the distance from the center to the region farthest from the center. In addition, the amplitude average value of the innermost area among the four areas, ie, the area closest to the aperture center which is the center of the antenna aperture 10, is set to 0 dB as a reference. On the other hand, the desired excitation phase distribution in FIG. 4B is described as a relative phase when the phase average value of the innermost area is set to 0 ° as a reference. It is 0 ° except that the phase of the third region from the opening center side is 180 °.

  From the relationship between the excitation phase φ and the excitation amplitude P shown in FIG. 3, since the change of the phase φ in the case where the excitation amplitude P is minimum is steep, such as the quantization error and the phase value setting error of the phase shifter It is difficult to set the phase accurately with the influence. Therefore, in the example shown in FIG. 4, the transmission system of each transmission / reception module connected to each of the element antennas in the second area from the aperture center side which is the area where the excitation amplitude P becomes a minimum is turned OFF. . If the excitation amplitude P is a minimum, the transmission / reception module itself may be turned off.

  In time modulated array technology, the excitation phase is usually given as the conjugate phase φ (2 states: φ1 = φ and φ2 = −φ). However, in order to obtain a broad beam having a width four times the beam width of the pencil beam as described above, it is necessary to have the excitation phase distribution shown in FIG. In the excitation phase distribution shown in FIG. 4B, the excitation phase of all the element antennas in the third region from the aperture center side is 180 °, and the phase is opposite to that of the other element antennas. This is for equivalently reducing the antenna aperture diameter as viewed from the beam pointing direction which is the direction. In the setting of the excitation phase in the antenna device of the present embodiment, the excitation phase of each transmission signal is set in accordance with the excitation phase distribution shown in FIG. 4 (b). If the relationship of the conjugate phase can be maintained at the excitation times T1 and T2, the setting of the excitation phase may be freely performed. There is no problem if a scanning phase is added during beam scanning.

  An example of the excitation phase distribution set at each of the excitation times T1 and T2 in consideration of the relationship shown in FIG. 3 is shown in FIG. As in FIG. 4, the horizontal axis is normalized by the distance R from the opening center. Here, the distance R is calculated assuming an analog phase shifter. The average value of the excitation phase of each element antenna in the first (innermost) region from the aperture center is taken as 0 °, ie, as a reference. As shown in FIGS. 5A and 5B, the excitation phase average values of the element antennas in the same region are in a conjugate relationship between the excitation times T1 and T2.

  As shown in FIG. 6A, a broad beam which is a transmission pattern obtained after applying the time modulation array technology and receiving the reflected waves of the respective transmission patterns at the excitation times T1 and T2 and performing time averaging by the time averaging processing unit 21. Shown in. Compared with the pencil beam shown in FIG. 6 (b), that is, the transmission beam formed by the conventional antenna device to which the time modulation array technology is not applied, it can be seen that the beam width is four times or more. This shows the effectiveness of broadening with time modulation array technology. When using the pencil beam type transmission pattern shown in FIG. 6 (b), it is necessary to electronically scan the pencil beam 11 within the search area as shown in FIG. 7 (a).

  Thus, using time-modulated array technology, that is, using two phases φ1 and φ2 in conjugate relation as the excitation phase of the transmission signal, these two phases are set to the excitation phase of the transmission signal according to the excitation times T1 and T2 Thus, the width of the transmission beam can be expanded.

For comparison reference, the transceiver module 2 ₁ from phase shifter is 2 _m has easily explained when widening the beam width of immobilized by the transmission pattern of the excitation phase of setting the transmit signal. For example, in a small aperture array antenna, a radiation pattern in the case of providing an excitation phase distribution with a phase delay in a tapered manner from the aperture center according to a quadratic function is as shown in FIG. In the example shown in FIG. 8, the excitation phase is set to be about 4 times the beam width of the pencil beam formed in the case of uniform excitation distribution, but the small aperture diameter, ie, It is difficult to achieve the desired performance because ripples due to the number of elements occur in the beam and the relative power drops significantly at a certain angle. In addition, since the small aperture array antenna has a small number of elements, the degree of freedom in phase setting is insufficient, and it is difficult to achieve broad beam formation only by control of setting the excitation phase to one specific phase.

  Next, the operation of the reception system of the antenna device according to the present embodiment will be described.

  When the antenna apparatus receives the reflected wave of the signal transmitted toward the target, it receives the multi-beam shown in FIG. 2 (b) in order to receive the reflected wave from the target in a wide angle coverage (wide angle range). Form. FIG. 2 (b) shows an example where pencil beams 12 to 18 form a receiving multi-beam. The formation method of the reception multi beam is shown below.

A reflected wave from the target is received at each of the element antennas ₁₁ to 1 _m . Hereinafter, the reflected wave is called a reception signal. Received signal received at each antenna element is input from the transceiver module 2 ₁ to each of the 2 _m, each transceiver module selects a receiving circuit in accordance with a control signal from the control unit 8. Each transmission / reception module sets the phase of the signal input from the element antenna to have a desired excitation phase distribution (a cophase that achieves a desired directivity direction as an array antenna), and outputs the phase to the combining and distributing circuit 3 . The combining and distributing circuit 3 selects an internal receiving system combining circuit in accordance with a control signal from the control unit 8. The reception system synthesis circuit of the synthesis and distribution circuit 3 synthesizes the reception signals inputted from the respective transmission / reception modules in units of sub-arrays. In addition, it is assumed that one or more element antennas form a sub-array, and which antenna forms which sub-array.

Received signal synthesized by the sub-array units in the synthesis distributing circuit 3 is output from the sub-array and the same number of receiver 5 ₁ to 5 _n. 5 _n from the receiver 5 ₁ includes a A / D (Analog / digital) converter, converts the received signal of the sub-array units input from the combining and distributing circuit 3 into a digital signal. The digitized received signal at each of the receiver 5 ₁ 5 _n is outputted from the time average processing unit 21 ₁ to 21 _n. Time averaging processor 21 ₁ from 21 _n is input from 5 _n from the receiver 5 _1, to time average between the digital reception signal for each subarray and the excitation time T1 above T2. The time average processing unit 21 ₁ to 21 _n, since notified excitation time T1 and T2 from the excitation time setting unit 22, the received signal to be time-averaging process is known. Further, although in the present embodiment are configured separately and and 5 _n from the receiver 5 ₁ Time averaging processor 21 ₁ from 21 _n, it may have a configuration in which collectively into one. That is, it may be to perform a process of the receiver 5 ₁ performed by 5 _n at time averaging processor 21 ₁ from 21 _n, the processing performed by the time-average processing unit 21 ₁ to 21 _n from the receiver 5 ₁ 5 It may be performed by _n . Received signal average time from the time average processing unit 21 ₁ 21 _n is output to the DBF unit 6, DBF unit 6, the time average processing unit 21 time-averaged received signal ₁ from 21 _n and the beam number min Digital arithmetic processing is performed using weight data, which is an excitation coefficient, to form a multi-beam covering a desired coverage area. Specifically, DBF unit 6 multiplies the weight data is excitation coefficients for each time-average processing unit 21 time-averaged received signal ₁ from in 21 _n, further after multiplying the excitation coefficients The received signals are summed to form a multi-beam that covers the desired coverage. The calculation result by the DBF unit 6 is output to the signal processing unit 7. When the antenna device configures a radar device, the signal processing unit 7 performs processing of detecting a reflection signal from a target based on the calculation result output from the DBF unit 6.

  The multi-beams in the antenna apparatus of the present embodiment are obtained as transmission / reception product patterns, but as described above, since they are broad beams that can be covered within the coverage by one transmission pattern, That is, there is a feature that the gain variation in the beam forming angle direction is small and the distance to the search target is difficult to be mistaken. In addition, by broadening the transmission pattern, the time for beam scanning in the coverage area can be saved, so that the search time can be shortened.

Moreover, since it is possible to obtain an arbitrary excitation amplitude distribution equivalently by time modulation array technology, assuming that the excitation time is 2T, the beam width of the broad beam in the transmission pattern is the beam width of the pencil beam every time 2T passes. It can be changed to 2 times, 3 times, etc. That is, the antenna device can change the beam width of the broad beam as needed and select the optimum beam width each time 2T elapses. Therefore, for example, when the location of the target has been limited within the search time, the antenna apparatus has a flexible operation such as narrowing the coverage area by the transmission broad beam to a narrow area around the target and searching in more detail. Can be realized. When the beam width of the broad beam is twice or three times the beam width of the pencil beam, for example, in the antenna device, the control unit 8 sets the antenna aperture 10 in two or three regions depending on the distance from the aperture center. divided, each antenna element group in the same region, i.e., to control the excitation phase of the antenna elements in the region unit, an instruction with respect to the transceiver module 2 ₁ 2 _m. Similarly, the beam width of the broad beam may be five or more times the beam width of the pencil beam.

  In addition, in time modulation array technology, the existing phase shifters incorporated in the transmission / reception module are controlled, and the desired excitation amplitude distribution is equivalently achieved by adjusting the excitation phase distribution, so that the transmission / reception module directly As compared with the case where the excitation amplitude distribution adjustment is performed by the amplitude control, the change in hardware is small and the cost merit is large.

  In the antenna device of the present embodiment, time modulation array technology is used to broaden the transmission pattern, but a desired excitation amplitude distribution can be set arbitrarily, so side lobe suppression pattern formation, multiple beams It is possible to cope with forming beam formation such as pattern formation. Moreover, it is also possible to use this beam forming method with the same configuration not for the transmission system but for the reception system.

  As described above, the antenna device according to the present embodiment includes a plurality of element antennas and transmission / reception modules connected to each element antenna, and each transmission / reception module transmits a signal during a first period. At the excitation time T1, the excitation phase of the signal transmitted from each element antenna is set to one of two phases in a conjugate relationship, and at the excitation time T2 which is the second period after the first period ends, each The excitation phase of the signal transmitted from the element antenna is set to the other of the two phases in a conjugate relationship. In addition, the time average value at excitation time T1 and the time average value at excitation time T2 of the received signal obtained by combining the reflected waves of the signals transmitted from each element antenna in units of subarrays are calculated, and reception in units of subarrays The receive beam is formed based on the time average value of the signal. As a result, it is possible to adjust the excitation distribution on the antenna aperture by equivalent amplitude control by the time modulation array technology to expand the beam width of the transmission radiation pattern from that of the pencil beam, and to shorten the search time. In particular, in a small aperture array antenna, beam width adjustment only with phase control is difficult in terms of electrical performance, and amplitude control is not suitable because it requires a change in transmission / reception modules as hardware. In this time modulation array technology, since an arbitrary equivalent amplitude distribution can be arbitrarily set from the time average by repetitive control of the excitation phase distribution 2 state in a conjugate relationship, it is excellent in electrical performance and applicability.

  The radar apparatus to which the antenna apparatus of this embodiment is applied is intended to shorten the search time by receiving multi-beam formation, but by broadening the transmission pattern by the time modulation array technology using the time weight concept, Further reduction in search time can be realized without the need for the transmission beam electronic scan time. In addition, since the beam width can be arbitrarily adjusted, the search coverage area can be varied temporally to make the search method more accurate. In addition, the application of the time modulation array technology provides an advantage in hardware change and cost.

  The configuration shown in the above embodiment shows an example of the contents of the present invention, and can be combined with another known technique, and one of the configurations is possible within the scope of the present invention. Parts can be omitted or changed.

1 ₁ from 1 _m element antenna, 2 ₁ from 2 _m transceiver modules, 3 synthesis distributing circuit, 4 a transmitter, 5 ₁ from 5 _n receivers, 6 DBF unit, 7 a signal processing unit, 8 a control unit, 10 an antenna aperture, 21 ₁ to 21 _n time averaging processing unit, 22 excitation time setting unit.

Claims (4)

Multiple element antennas for both transmission and reception,
As many transmission / reception modules as the element antennas, which are connected to the element antennas and transmit / receive signals via the element antennas;
A combining and distributing circuit that combines the signals received by each of the transmitting and receiving modules in units of subarrays, and distributes transmitting signals generated by a transmitter to each of the transmitting and receiving modules;
Time averaging processing units as many as the sub-arrays that time-average the received signals combined in the sub-array units;
A digital beam forming unit that performs arithmetic processing on the reception signal that has been time-averaged by the time averaging processing unit to form a reception multi-beam;
A control unit configured to control each of the transmission / reception modules and switch an excitation phase of a signal transmitted from each of the plurality of element antennas between one of the two different phases and the other every time a specified time elapses;
Equipped with
The control unit divides the plurality of element antennas into a plurality of element antenna groups based on the distance from the center of the antenna aperture formed by the plurality of element antennas, and transmits from each of the element antennas belonging to the same group Control each of the transmitting and receiving modules so that the excitation phase of the input signal is the same,
An antenna device characterized by Let the two different phases be two phases in a conjugate relationship,
The antenna device according to claim 1, characterized in that: The control unit changes the number of element antennas belonging to each element antenna group each time a time twice as long as the specified time elapses .
The antenna device according to claim 1 or 2 , characterized in that: A radar apparatus comprising the antenna apparatus according to any one of claims 1 to 3 .

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