JP6433567B2 - Transmission / reception antenna, slit design method - Google Patents

Description

  The present invention relates to a transmission / reception antenna for radar and a method for designing a slit of the transmission / reception antenna.

  As a transmission / reception antenna for radar, the antenna of Patent Document 1 is known as a conventional technique. In Patent Document 1, a partition wall is provided on the radome to suppress wraparound from the transmitting antenna unit to the receiving antenna unit, thereby improving isolation between transmission and reception. As a technique for improving isolation between transmission and reception by synthesizing signals having opposite phases, the technique of Patent Document 2 is known.

JP 2012-093305 A JP 2005-269592 A

  In the antenna of Patent Document 1, since the reflector is not in the radome, it is difficult to control the shape of the beam. Therefore, when considering a transmission / reception antenna provided with a reflector in the radome, transmission / reception antennas as shown in FIGS. 6 is a plan view of a transmission / reception antenna having a reflector, FIG. 7 is a cross-sectional view of the transmission / reception antenna along line AA in FIG. 6, and FIG. 8 is a cross-sectional view of the transmission / reception antenna along line BB in FIG. is there. The transmission / reception antenna 900 includes a back plate 920, two reflectors 930, two reflector / isolators 940, a plurality of transmission elements 950, a plurality of reception elements 960, and a radome 910, as shown in FIGS.

  Although the transmission / reception antenna 900 shares the back plate 920, the transmission antenna 901 and the reception antenna 902 are arranged in one radome 910. In the transmission / reception antenna 900, the shape of the xz plane beam of the transmission antenna 901 is determined by the reflector 930 and the reflector / isolator 940 on the transmission antenna 901 side, and the beam shape of the xz plane of the reception antenna 902 is the reflector on the reception antenna 902 side. 930 and reflector / isolator 940. Further, by adjusting the length a of the reflector 930 and the reflector / isolator 940 and the distance b between the transmission antenna 901 and the reception antenna 902, the wraparound between transmission and reception can be adjusted. If the intensity and phase of the reflected wave and the sneaking radio wave at the radome 910 are adjusted to the opposite phase, the isolation can be improved.

  However, in the configuration of the transmission / reception antenna 900, the wraparound phase and intensity adjustment for canceling the reflection generated in the radome 910 are performed by adjusting the length a of the reflector 930 and the reflector / isolator 940 for determining the beam shape, the transmission antenna 901, and the reception antenna. Must be performed at an interval b with 902. Accordingly, there is a problem that it is difficult to design to satisfy both the adjustment of the wraparound and the shape of the beam.

  An object of the present invention is to provide a transmission / reception antenna having a structure that is easy to design and a method for designing a slit of the transmission / reception antenna.

  The transmission / reception antenna of the present invention includes two reflectors, a back plate, an isolator, a plurality of transmitting elements, a plurality of receiving elements, and a radome. The two reflectors are conductive plates and are arranged to face each other. The back plate is a conductive flat plate and contacts both of the two reflectors. The isolator is a conductive flat plate, is disposed between two reflectors so as to face both reflectors, and is in linear contact with the back plate. The isolator has a slit for allowing radio waves from a plurality of transmitting elements to wrap around the plurality of receiving elements. The plurality of transmitting elements are arranged between one of the two reflectors and the isolator. The plurality of receiving elements are arranged between the other of the two reflectors and the isolator. The radome covers two reflectors, a back plate, an isolator, a plurality of transmitting elements, and a plurality of receiving elements.

  According to the transmission / reception antenna of the present invention, the shape of the beam is determined by the reflector, and the wraparound from the transmission element side to the reception element side can be adjusted by the slit provided in the isolator, so that the transmission / reception antenna design is easy.

The top view of the transmission / reception antenna of this invention. Sectional drawing in the AA of FIG. 1 of the transmission / reception antenna of this invention. Sectional drawing in the BB line of FIG. 1 of the transmission / reception antenna of this invention. Sectional drawing in the CC line of FIG. 2 of the transmission / reception antenna of this invention. The figure which shows the flow of the design method of the slit of this invention. The top view of the transmission / reception antenna which has a reflector. Sectional drawing in the AA of FIG. 6 of the transmission / reception antenna which has a reflector. Sectional drawing in the BB line of FIG. 6 of the transmission / reception antenna which has a reflector.

  Hereinafter, embodiments of the present invention will be described in detail. In addition, the same number is attached | subjected to the structure part which has the same function, and duplication description is abbreviate | omitted.

  1 is a plan view of the transmission / reception antenna of the present invention, FIG. 2 is a cross-sectional view of the transmission / reception antenna of the present invention taken along line AA in FIG. 1, and FIG. FIG. 4 is a sectional view of the transmitting / receiving antenna of the present invention taken along line CC in FIG. As shown in the figure, the x direction, the y direction, and the z direction are directions orthogonal to each other. The transmitting / receiving antenna 100 of the present invention includes two reflectors 130, a back plate 120, an isolator 140, a plurality of transmitting elements 150, a plurality of receiving elements 160, and a radome 110.

  The two reflectors 130 are conductive plates and are arranged to face each other. The back plate 120 is a conductive flat plate and contacts both of the two reflectors. In the drawing, the back plate 120 has the z direction as the normal direction. Further, the two reflectors 130 are arranged so as to face each other so that the line in contact with the back plate 120 is two straight lines parallel to the y direction.

  The isolator 140 is a conductive flat plate, is disposed between the two reflectors 130 so as to face both the reflectors 130, and contacts the back plate 120 linearly. In the figure, the isolator 140 is disposed between two reflectors 130 so that the x direction is a normal direction and is in contact with the back plate 120 in a straight line. Further, the isolator 140 has a slit 145 for allowing radio waves from the plurality of transmitting elements 150 to go around to the plurality of receiving elements 160. A plurality of slits 145 may be provided. In that case, they may be arranged in the y direction. However, the plurality of slits 145 may change the distance from the back plate 120 or may have different shapes. The shape of the slit 145 is not limited to an elongated hole, and may be a hole such as a circle or a square.

  The plurality of transmission elements 150 are arranged between one of the two reflectors 130 and the isolator 140. The plurality of receiving elements 160 are arranged between the other of the two reflectors 130 and the isolator 140 in parallel with the arrangement of the plurality of transmitting elements 150. In the figure, the transmitting element 150 and the receiving element 160 are arranged in the y direction. For example, the back plate 120 may be formed on one surface of the dielectric substrate, and the transmitting element 150 and the receiving element 160 may be formed on the other surface by a patch antenna. The radome 110 covers the two reflectors 130, the back plate 120, the isolator 140, the plurality of transmitting elements 150, and the plurality of receiving elements 160.

  In the transmission / reception antenna 100, the shape of the beam in the xz plane may be determined by the shape of the reflector 130. The shape of the beam on the yz plane may be determined by the power supplied to each of the plurality of transmitting elements 150 and the plurality of receiving elements 160. Then, the wraparound from the transmitting element 150 to the receiving element 160 may be adjusted by the isolator 140 and the slit 145 so as to cancel the influence of the reflection at the radome 110. That is, it is only necessary to adjust so that the radio wave that wraps around has the same intensity as the reflected wave and close to the opposite phase by the isolator 140 and the slit 145. Therefore, the design is easy. Further, the transmission / reception antenna 100 can be made smaller than the transmission / reception antenna 900 because the transmission antenna and the reception antenna can be integrated.

<Slit design method>
The transmission / reception antenna 100 is an antenna used for FM-CW radar, for example, and outputs a constant power while changing the frequency, and receives a reflected wave from the observation target. In this case, since the frequency changes, it is impossible to completely reverse the phase at all frequencies. In addition, the slit 145 is located at the position of the near-field pattern of radio waves, and even if a technique such as simulation is used, the calculation result and the actual characteristic often do not match. Therefore, a method for designing (adjusting) the slit 145 while confirming the characteristics by observation with an actual transmitting / receiving antenna will be described below.

  FIG. 5 shows a flow of the slit design method. In the design transmitting / receiving antenna 100, the back plate 120 has a structure in which the isolator 140 can be attached and detached. For example, an insertion hole may be provided, and the isolator 140 may be inserted and fixed therein. The slit design method includes a non-reflection data acquisition step (S10), a reflection data acquisition step (S20), a target data acquisition step (S30), and a comparison step (S40). In the non-reflecting data acquisition step (S10), radio wave data received by the plurality of receiving elements 160 when the isolator 140 without the slit 145 is attached without the radome 110 is obtained as non-reflecting data. In the non-reflective data acquisition step (S10), radio wave data when there is no reflection at the radome 110 can be acquired. Therefore, the reflector 130, the isolator 140, etc. may be adjusted so as to obtain the highest possible performance. In the reflection data acquisition step (S20), radio wave data received by the plurality of receiving elements 160 when the isolator without the slit 145 is attached with the radome 110 provided is obtained as reflection data. The difference between the non-reflective data and the reflected data is the influence of the reflected wave generated by the radome 110. In the target data acquisition step (S30), radio wave data is obtained from the non-reflective data and the reflection data when radio waves having the same intensity as the reflected wave generated by the radome 110 and opposite in phase are added to the non-reflective data. To do.

  In the comparison step (S40), radio wave data received by the plurality of receiving elements 160 when the isolator 140 having the slit 145 is attached without the radome 110 is obtained as wraparound data, and the wraparound data is set as target data. Compare with The comparison step (S40) may be repeated while changing at least one of the number, position, and shape of the slits 145 of the isolator 140 to obtain the slits 145 whose wraparound data is close to the target data (S50). For example, several isolators 140 are prepared in advance, and wraparound data is obtained from them. Then, it is only necessary to further adjust the isolator 140 from which the rounding data closest to the target data is obtained. Then, the process may be repeated until an isolator 140 that satisfies the requirements of the transmission / reception antenna 100 is found. According to the slit designing method of the present invention, the comparison step (S40) is an iterative process, but it is only necessary to attach and detach the isolator 140 to and from the back plate 120 without the radome 110. Can do.

100, 900 Transmitting / receiving antenna 110, 910 Radome 120, 920 Back plate 130, 930 Reflector 140 Isolator 145 Slit 150, 950 Transmitting element 160, 960 Receiving element 901 Transmitting antenna 902 Receiving antenna 940 Reflector / isolator

Claims (4)

The x direction, the y direction, and the z direction are directions orthogonal to each other,
A back plate that is a conductive flat plate with the z direction as the normal direction;
Two reflectors, which are conductive plates, arranged opposite to each other so that the lines in contact with the back plate are two parallel straight lines in the y direction;
An isolator that is a conductive flat plate and is arranged so that the x direction is a normal direction between the two reflectors and is in linear contact with the back plate;
A plurality of transmitting elements arranged in the y direction between one of the two reflectors and the isolator;
A plurality of receiving elements arranged in the y direction between the other of the two reflectors and the isolator;
A radome covering the two reflectors, the back plate, the isolator, the plurality of transmitting elements, and the plurality of receiving elements;
With
The isolator has a slit for turning radio waves from the plurality of transmitting elements to the plurality of receiving elements,
A plurality of the slits are arranged in the y direction;
Some of the slits have different distances from the back plate,
A transmitting / receiving antenna characterized in that radio wave data received by the plurality of receiving elements when an isolator having the slit is attached without the radome can be obtained. Two reflectors which are conductive plates and are arranged opposite each other;
A back plate that is a conductive flat plate that contacts both of the two reflectors;
An isolator that is a conductive flat plate and is disposed between the two reflectors so as to face both reflectors and linearly contacts the back plate;
A plurality of transmitting elements arranged between one of the two reflectors and the isolator;
A plurality of receiving elements arranged between the other of the two reflectors and the isolator;
A radome covering the two reflectors, the back plate, the isolator, the plurality of transmitting elements, and the plurality of receiving elements;
With
The isolator has a plurality of slits for turning radio waves from the plurality of transmitting elements to the plurality of receiving elements,
The plurality of slits include those having different distances from the back plate. The x direction, the y direction, and the z direction are directions orthogonal to each other,
A back plate that is a conductive flat plate with the z direction as the normal direction;
Two reflectors, which are conductive plates, arranged opposite to each other so that the lines in contact with the back plate are two parallel straight lines in the y direction;
An isolator disposed between the two reflectors so that the x direction is a normal direction and is in linear contact with the back plate;
A plurality of transmitting elements arranged in the y direction between one of the two reflectors and the isolator;
A plurality of receiving elements arranged in the y direction between the other of the two reflectors and the isolator;
A radome covering the two reflectors, the back plate, the isolator, the plurality of transmitting elements, and the plurality of receiving elements;
With
The isolator has a slit for turning radio waves from the plurality of transmitting elements to the plurality of receiving elements,
A plurality of the slits are arranged in the y direction;
The plurality of slits include those having different distances from the back plate. It is a design method of the slit which the transmission / reception antenna in any one of Claims 1-3 has,
The back plate has a structure in which an isolator can be attached and detached.
Non-reflective data acquisition step for acquiring radio wave data received by the plurality of receiving elements when the isolator without the slit is attached without the radome;
A reflection data acquisition step of obtaining data of radio waves received by the plurality of receiving elements when an isolator without the slit is attached in a state provided with the radome;
From the non-reflected data and the reflected data, obtain a radio wave data when a radio wave having the same intensity as the reflected wave generated by the radome and an opposite phase is added to the non-reflective data; ,
A comparison step of acquiring radio wave data received by the plurality of receiving elements when the isolator having the slit is attached in the absence of the radome and obtaining the wraparound data, and comparing the wraparound data with the target data. Have
The slit design method, wherein the comparison step is repeated while changing at least one of the number, position, and shape of the slit of the isolator, and the slit in which the wraparound data is close to the target data is obtained.

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