JP2017175596A - Antenna and radar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna capable of making a detection angle of a radar a wider angle.SOLUTION: The antenna includes: a first slot antenna; and a second slot antenna provided apart from the first slot antenna. Between the first slot antenna and the second slot antenna and in front of a surface which is a surface on which a slot element of the first slot antenna is formed and a surface of the second slot antenna, a first member of a conductor is provided.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an antenna and a radar.

  In a radar using a slot antenna, a reflected wave of a radar wave such as a radio wave transmitted from a transmission antenna is simultaneously received by each of a plurality of slot antennas arranged in a horizontal direction at a certain interval. And the position of a detection target object is detected based on the phase difference of a received wave. Such a radar is used as an automotive radar as disclosed in Non-Patent Document 1, for example.

Kunio Sugawara, 3 others, “Millimeter wave waveguide slot array antenna for automobile radar”, “R & D Review of Toyota CRDL”, Vol. 36 No. 3, September 2001, p. 35-40

  Such a radar is required to have a wider detection angle, which is an angle at which the position can be detected.

  An antenna according to the present invention is provided between a first slot antenna, a surface on which a slot element of the first slot antenna and the first slot antenna is formed, and a surface of the second slot antenna. One or more first recesses are formed in the region.

  The radar according to the present invention is equipped with the antenna described above.

  According to the present invention, the radar detection angle can be made wider.

It is the figure which represented typically an example of the structure of the radar carrying the antenna concerning embodiment. It is the figure which represented typically an example of the structure of the antenna. It is the table | surface which put together 14 conditions used for the simulation which inventors performed. 6 is a diagram illustrating an outline of a configuration of an antenna model under condition 1. FIG. 6 is a diagram illustrating an outline of a configuration of an antenna model under condition 2. FIG. 6 is a diagram illustrating an outline of a configuration of an antenna model under condition 3. FIG. 6 is a diagram illustrating an outline of a configuration of an antenna model under condition 4. FIG. 6 is a diagram showing an outline of a configuration of an antenna model under condition 5. FIG. 10 is a diagram illustrating an outline of a configuration of an antenna model under condition 6. FIG. 10 is a diagram illustrating an outline of a configuration of an antenna model under condition 7. FIG. 10 is a diagram showing an outline of a configuration of an antenna model under condition 8. FIG. 10 is a diagram illustrating an outline of a configuration of an antenna model under condition 9. FIG. 10 is a diagram illustrating an outline of a configuration of an antenna model under condition 10. FIG. 6 is a diagram illustrating an outline of a configuration of an antenna model under condition 11. FIG. 6 is a diagram showing an outline of a configuration of an antenna model under condition 12. FIG. 10 is a diagram illustrating an outline of a configuration of an antenna model under condition 13. FIG. FIG. 10 is a diagram showing an outline of a configuration of an antenna model under condition 14; It is a figure showing the simulation result of the reception strength in the antenna model of condition 1. It is a figure showing the simulation result of the receiving intensity in the antenna model of condition 2. FIG. 11 is a diagram illustrating a simulation result of reception intensity in an antenna model under condition 3; FIG. 11 is a diagram illustrating a simulation result of reception intensity in an antenna model under condition 4; FIG. 10 is a diagram illustrating a simulation result of reception intensity with an antenna model under condition 5; FIG. 10 is a diagram illustrating a simulation result of reception intensity in an antenna model under condition 6; It is a figure showing the simulation result of the receiving strength in the antenna model of condition 7. FIG. 10 is a diagram illustrating a simulation result of reception intensity in an antenna model under condition 8; FIG. 10 is a diagram illustrating a simulation result of reception intensity with an antenna model under condition 9; FIG. 11 is a diagram illustrating a simulation result of reception intensity with an antenna model under condition 10; FIG. 10 is a diagram illustrating a simulation result of reception intensity in an antenna model under condition 11; FIG. 11 is a diagram illustrating a simulation result of reception intensity with an antenna model under condition 12; It is a figure showing the simulation result of the receiving strength in the antenna model of condition 13. FIG. 14 is a diagram illustrating a simulation result of reception strength with an antenna model under condition 14; It is the list showing the result of the simulation using the antenna model of conditions 1-14. FIG. 16 is a diagram showing an outline of a configuration of an antenna model under condition 15; It is a figure for demonstrating an example of the manufacturing method of an antenna. It is a figure for demonstrating an example of the manufacturing method of an antenna. It is a figure for demonstrating the other example of the groove | channel provided between adjacent slot antennas. It is a figure for demonstrating an example of the attachment method to the board | substrate of a board member. It is a figure for demonstrating the direction in a simulation result. It is a figure showing an example of the structure of the antenna concerning 7th Embodiment. It is a figure showing an example of the structure of the antenna concerning 8th Embodiment.

[Description of Embodiment]
This embodiment includes at least the following.
(1) comprising a first slot antenna and a second slot antenna provided apart from the first slot antenna, between the first slot antenna and the second slot antenna, An antenna, wherein a first member of a conductor is provided in front of a surface on which a slot element of one slot antenna is formed and a surface of a second slot antenna.
According to said structure, even if it is a case where the space | interval of a slot antenna is narrowed, the fall of isolation etc. can be suppressed. Therefore, the detection angle can be made wider without reducing the detection accuracy of the radar equipped with the antenna.

(2) The first slot antenna and the second slot antenna are arranged side by side in the first direction, and when viewed from the first slot antenna, one of the two sides in the first direction has a second The other slot antenna is not arranged on the other side, and the second member of the conductor is provided in front of the surface of the first slot antenna on the other side. The antenna according to (1).
According to the above configuration, even when the interval between the slot antennas is narrowed, it is possible to suppress variations in the received intensity of the radar wave by each of the plurality of slot antennas. Therefore, the detection performance of the radar equipped with the antenna can be made highly accurate.

(3) The first slot antenna and the second slot antenna are arranged side by side in the first direction, and the first slot antenna and the second slot antenna are orthogonal to the first direction, respectively. The antenna according to (1) or (2), having a plurality of slot elements arranged along the second direction.
According to said structure, the detection precision of the radar carrying the said antenna can be improved.

(4) The distance between the first slot antenna and the second slot antenna is 1.5λ (λ: wavelength of the frequency used by the antenna) or less, and any one of (1) to (3) The described antenna.
According to said structure, the detection angle of the radar carrying the said antenna can be made into a wider angle.

(5) The antenna according to (4), wherein a gap between the first slot antenna and the second slot antenna is (1/20) λ or more.
According to said structure, it can make it easy to arrange | position a 1st member in narrowing the space | interval of a 1st slot antenna and a 2nd slot antenna.

(6) The first member according to any one of (1) to (5), wherein the first member is provided in front of the surfaces of the first slot antenna and the second slot antenna. antenna.
According to said structure, the detection precision of the radar carrying the said antenna can be improved.

(7) A substrate having a first slot antenna and a second slot antenna is formed, and the substrate has a first surface that forms a surface of the first slot antenna and a surface of the second slot antenna. The antenna according to any one of (1) to (6), wherein the first member is provided in front of the first surface.
According to the above configuration, the antenna can be easily configured and can be easily handled.

(8) The first slot antenna and the second slot antenna are arranged side by side in the first direction, and have a support portion for supporting the first member with respect to the first surface of the substrate, At least one of the slot element of the first slot antenna and the slot element of the second slot antenna is formed in one of the first directions when viewed from the support part, and no support part is provided. A support portion is provided at a position where neither the slot element of the first slot antenna nor the slot element of the second slot antenna is formed in any of the first directions when viewed from the support portion. ) Antenna.
According to said structure, while a 1st member is stably supported with respect to a board | substrate, manufacture of the antenna which has a 1st member becomes easy.

(9) The substrate has a stacked structure in which a plurality of plates are stacked, and the plurality of plates includes a first plate having a first surface, and a second plate disposed in front of the first surface. The first plate has a first through hole forming a slot element, and the second plate communicates with the first through hole and is larger than the first through hole. The antenna according to (8), which has a through hole and a region that forms a support portion.
According to said structure, formation of an antenna can be made easy. In particular, when the wavelength of the frequency used by the antenna is a small wavelength such as a millimeter wave, the antenna can be formed more easily.

(10) The first slot antenna and the second slot antenna are arranged side by side in the first direction, and the first member is provided on the first surface of the substrate and is orthogonal to the first direction. The antenna according to any one of (7) to (9), which is a metal plate extending in a second direction.
According to said structure, a 1st member can be formed easily.

(11) The antenna according to any one of (1) to (10), wherein the member is provided at an equal position from the first slot antenna and the second slot antenna.
According to said structure, the influence of the 1st member with respect to each of the 1st slot antenna and 2nd slot antenna which are adjacent on both sides of the 1st member can be equalized.

(12)
A radar equipped with the antenna according to any one of (1) to (11).
According to said structure, a detection angle can be made into a wider angle.

(13) The radar according to (12), wherein the detection angle is ± 20 ° or more.
According to said structure, a detection angle can be made into a wider angle.

[Details of the embodiment]
Hereinafter, preferred embodiments will be described with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, these descriptions will not be repeated.

[First Embodiment]
An antenna using a slot antenna may be mounted on a radar. The slot antenna is an antenna for wireless communication, and has a waveguide described later and a slot element provided for the waveguide. A waveguide is a tube having a circular or square cross section used for transmission of radio waves. The slot element is a through hole that goes from the hollow of the waveguide toward the outside. The antenna using the slot antenna includes a plurality of slot antennas arranged so that the longitudinal directions of the waveguides are parallel to each other. In such a radar, the angle of the object to be detected with respect to the antenna is detected based on the phase difference of radar waves (radio waves) simultaneously received by a plurality of slot antennas constituting a plurality of receiving antenna systems. As an example, the antenna is installed with the longitudinal direction of the tubes of the plurality of slot antennas arranged as described above being vertical.

  Each of the plurality of slot antennas constituting each of the plurality of receiving antenna systems is designed based on the wavelength of the radar wave to be received by the receiving antenna system. The frequency of the radar wave to be received by the receiving antenna system is also called the frequency used by the antenna. For example, in a radar that uses millimeter-wave radio waves called millimeter-wave radar as radar waves, each slot antenna included in the receiving antenna system transmits a 20 GHz or higher millimeter-wave radio wave transmitted from the transmitting antenna system. It is designed to be able to receive.

  By narrowing the interval between the slot antennas arranged in parallel to the receiving antenna system as much as possible, the radar detection angle can be made wider.

  However, if the interval between adjacent slot antennas is narrowed, the isolation between adjacent slot antennas decreases. Isolation represents the degree of difficulty of affecting between antennas, for example, the degree of difficulty of influence of received signals. As the isolation between the slot antennas decreases, the purity of the received signal between these slot antennas decreases, leading to a decrease in radar detection performance. Moreover, interference between adjacent slot antennas occurs by narrowing the interval between the slot antennas. And thereby, the dispersion | variation in the directivity of the receiving intensity in a horizontal surface becomes large. Further, in order to narrow the interval between the slot antennas, the slot antennas must be arranged in one row (that is, one waveguide) for the receiving antenna system. For this reason, the antenna gain is reduced as compared with a case where a plurality of slot antennas (that is, a plurality of waveguides) are arranged in the horizontal direction in one antenna system for reception. The antenna gain refers to the intensity of energy at the radiation angle at which radiation is maximum, and specifically refers to the ratio of received power when the target antenna and the reference antenna receive signals in the same electric field. These are factors that reduce the detection accuracy of the radar.

  Therefore, the inventors can detect the position of the detection object with high accuracy at a wider detection angle in the mounted radar by narrowing the slot antenna interval while suppressing the above factors. Designed an antenna.

<Antenna configuration>
FIG. 1 is a diagram schematically showing an example of the configuration of a radar 300 equipped with an antenna 100 according to the present embodiment. In FIG. 1, a metal plate 50 described later is omitted. FIG. 2 is a diagram schematically illustrating an example of the configuration of the antenna 100. FIG. 2 is a cross-sectional view at the position AA in FIG.

  1 and 2, antenna 100 includes a plurality of slot antennas 20A to 20E. The slot antennas 20A to 20E will be referred to as the slot antenna 20 as a representative.

  One slot antenna has one waveguide and a plurality of slot elements sharing the waveguide. Two or more slot antennas are arranged in a direction (first direction) in which the longitudinal directions of the waveguides are parallel to each other to constitute one antenna. The antenna system refers to one or more slot antenna groups arranged, and in this embodiment, one slot system is configured by one slot antenna.

  Specifically, referring to FIGS. 1 and 2, the slot antennas 20 </ b> A to 20 </ b> E are each provided with one waveguide 11 </ b> A to 11 </ b> E and the longitudinal direction (second direction) of each waveguide 11. And a plurality of slot elements 12 arranged along. The waveguides 11A to 11E are referred to as the waveguide 11 as a representative. Providing each slot antenna 20 with a plurality of slot elements 12 can improve the detection accuracy of the radar 300 on which the antenna 100 is mounted.

  In the antenna 100, the plurality of slot antennas 20 are disposed inside a plate member 10 formed of a conductor such as metal. That is, it can be said that a plurality of slot antennas 20 are formed on the plate 10. This plate material 10 is referred to as a substrate 10. By adopting a configuration in which a plurality of slot antennas 20 are formed on the substrate 10, the antenna 100 can be easily configured. In addition, the antenna 100 can be easily handled.

  The surface of the slot antenna 20 on which the slot element 12 is provided is referred to as the surface of the slot antenna 20. A surface including all the surfaces of the plurality of slot antennas 20 is a front surface of the antenna 100. The surface (first surface) of the substrate 10 forms the surface of all of the plurality of slot antennas 20. In other words, the plurality of slot antennas 20 are arranged in the substrate 10 such that the surfaces thereof coincide with or substantially coincide with the surface of the substrate 10. The term “substantially coincidence” here refers not only to the case where the surfaces of all of the plurality of slot antennas 20 are completely coincident with the substrate 10, but, for example, the surface of the slot antenna 20 is slightly uneven with respect to the surface of the substrate 10. Is meant to include The waveguide 11 is disposed in the substrate 10 so that the longitudinal direction of the tube is parallel.

  In the following description, the direction in which the waveguides 11 are arranged, that is, the direction (first direction) orthogonal to the tube longitudinal direction of the waveguides 11 is defined as the width direction of the antenna 100. A front direction from the front of the antenna 100 is a front direction of the antenna 100, and a rear direction from the front of the antenna 100 is a rear direction of the antenna 100. The direction from the front of the antenna 100 to the rear indicates the direction from the front of the antenna 100 toward the inside of the substrate 10. The front from the front of the antenna 100 is the reverse direction from the rear, and refers to the direction far from the substrate 10 with the front of the antenna 100 as a base point.

Referring to FIG. 1, as an example, a plurality of slot elements 12 included in one slot antenna 20 are arranged in two rows along two straight lines C _SL and C _SR in the tube longitudinal direction for one waveguide 11. Arranged. The plurality of slot elements 12 need only be generally arranged along two straight lines C _SL and C _SR , and their centers are not necessarily directly above one of the two straight lines C _SL and C _SR. May be. The two straight lines C _SL and C _SR are located at equal distances across the center line Cw of the waveguide 11 in the longitudinal direction of the tube. The center line Cw is also the center line in the width direction of the slot antenna 20. The plurality of slot elements 12 are arranged at equal intervals in the longitudinal direction of the pipe along the straight lines C _SL and C _SR . A plurality of slot elements 12 and a plurality of slot elements 12 along the line C _SR along the line C _SL, the position in the width direction do not match, are arranged alternately. The plurality of slot elements may all have the same shape, or may have a slight size difference. In the following description, all the shapes of a plurality of slot elements 12 and the same as, linear C _SL of the center are two, C _SR located either directly above two straight lines C _SL, along the C _SR Shall be arranged.

  The plurality of slot antennas 20A to 20E are arranged separately into the slot antennas 20A to 20D and the slot antenna 20E. In the slot antenna 20A, the slot antenna 20B is arranged on one side of both sides in the width direction, and no other slot antenna is arranged on the other side. Further, in the slot antenna 20D, the slot antenna 20C is arranged on one side of both sides in the width direction, and no other slot antenna is arranged on the other side.

  Each of the slot antennas 20A to 20D is connected to the receiver 170. Each of the slot antennas 20A to 20D functions as a receiving antenna system. The slot antenna 20E is connected to the transmitter 150. The slot antenna 20E functions as a transmission antenna system.

  In the receiving antenna system, the interval between adjacent slot antennas 20 is, for example, 1.5λ or less. The interval between adjacent slot antennas 20 is a distance L1 between the center line Cw of the slot antenna 20 and the center line Cw of the slot antenna 20 adjacent to the slot antenna 20 with reference to FIG. λ is the wavelength of the operating frequency of the antenna. When the radar 300 is a millimeter wave radar, λ is 15 mm. Preferably, the interval L1 between adjacent slot antennas 20 is 1.0λ or less. This is because the detection angle in the radar 300 can be made wider by making the interval L1 between the slot antennas 20 as narrow as possible.

  Further, the gap between adjacent slot antennas 20 is, for example, (1/20) λ or more. The gap between adjacent slot antennas 20 is a gap between the waveguides 11 of the adjacent slot antennas 20. Specifically, referring to FIG. 1, the gap between adjacent slot antennas 20 is a distance L <b> 2 between end portions of waveguide 11 on the side close to adjacent slot antennas 20. By narrowing the gap L2 between the slot antennas 20 while the interval L1 between the adjacent slot antennas 20 is narrowed as described above, a groove 40 and a metal plate 50 which will be described later are easily arranged.

  The transmitter 150 generates a transmission wave having a wavelength of the use frequency of the antenna. When the radar 300 is a millimeter wave radar, the transmitter 150 generates a transmission wave in the millimeter wave band of 20 GHz or more. The transmission wave generated in the transmitter 150 reaches the plurality of slot elements 11 provided in the slot antenna 20E through the waveguide 11E. Then, the transmission wave is emitted from each slot element 11 in a predetermined direction.

  The radio wave having the wavelength of the use frequency of the antenna that has reached the antenna 100 is received by the plurality of slot elements 11 provided in each of the slot antennas 20A to 20D. The received wave is sent from the slot element 11 to the receiver 150. When the radar 300 is a millimeter wave radar, a millimeter wave band radio wave of 20 GHz or more is sent to the receiver 150. The receiver 150 performs a prescribed process on the radio waves received by the slot antennas 20A to 20D. When a detection target exists in the detection range of the radar 300, the radio wave emitted from the slot antenna 20E is reflected by the detection target. The reflected radio waves are received by the slot antennas 20A to 20D.

  Based on the time from when the radio wave is emitted to when it is received, the distance of the detection target from the antenna 100 is calculated. Based on the phase difference of the radio wave received by each of the slot antennas 20A to 20D, the angle of the detection target with respect to the antenna 100 is calculated.

  In the receiving antenna system, one or more first recesses are formed in a region between two adjacent slot antennas 20 on the surface of the substrate 10. For example, one or more first recesses are formed on the surface of the substrate 10 between the slot antenna 20A and the slot antenna 20B. The first recess is, for example, a groove extending in the tube longitudinal direction of the waveguide 11. By forming the first recess as a groove, it can be easily formed. That is, as shown in FIG. 1 and FIG. 2, the tube longitudinal direction of the waveguide 11 is formed on the surface of the substrate 10 between the adjacent slot antennas 20A and 20B, 20B and 20C, and 20C and 20D, respectively. Grooves 40B, 40C, and 40D extending in the direction are formed. The grooves..., 40B, 40C, 40D,.

  Specifically, referring to FIG. 1, groove 40 that is the first recess extends along center line Cg. The center line Cg is parallel to the longitudinal direction of the waveguide 11. Preferably, the first concave portion is provided at a position at an equal distance from the two adjacent slot antennas 20. That is, the distance between the center line Cg and the center line Cw of each of the two adjacent slot antennas 20 is a distance l (el). The distance l (el) has a relationship of L = 2 × l (el) with respect to the distance L1 between the center lines Cw. By providing the groove 40 at such a position, the influence of the groove 40 on each of the two adjacent slot antennas 20 with the groove 40 interposed therebetween can be made uniform. Moreover, when an example of the manufacturing method mentioned later is employ | adopted for the manufacturing method of the antenna 100, formation of the antenna 100 can be made easy.

  Preferably, the surfaces of the substrate 10 on both sides of the slot antennas 20A and 20D arranged at both ends in the width direction shown in FIG. 1 are not adjacent to the other slot antennas, that is, outside the receiving antenna system. In addition, for example, second recesses which are grooves 40A and 40E extending in the tube longitudinal direction of the waveguide 11 are further provided.

  Referring to FIG. 2, preferably, in the receiving antenna system, the conductor is placed in front of the surface of the substrate 10 between two adjacent slot antennas 20 (a position having a positive distance in the front direction). A first member is provided. The conductor is a metal, for example. The first member of the conductor can be easily formed by using a metal plate. Similarly to the recess, the surface of the substrate 10 on both sides outside the receiving antenna system may be provided with a second member of a conductor that is a metal plate.

  The length of this member in the width direction of the antenna 100 is shorter than the gap L <b> 2 between the waveguides 11 of the two adjacent slot antennas 20. This member is, for example, a plate member (metal plate) such as a metal extending in the longitudinal direction of the waveguide 11. That is, as shown in FIG. 2, each of the slot antennas 20A and 20B, 20B and 20C, and 20C and 20D is guided to a position having a positive distance in the front direction from the surface of the substrate 10. Metal plates 50A, 50B and 50C extending in the longitudinal direction of the wave tube 11 are formed. The metal plates 50A,... Are representatively referred to as a metal plate 50.

  Note that either the recess such as the groove 40 or the member such as the metal plate 50 may be provided in the antenna 100, or only one of them may be provided.

<Effect verification>
The inventors who designed the antenna 100 performed simulation under various conditions using a part of the antenna 100 and changing the grooves 40A to 40E as the recesses and the metal plates 50A to 50C as the members. Then, the antenna gain, the directivity of reception, and the isolation between the antenna systems for reception were evaluated, and the design effect of the antenna 100 was verified.

<Details of conditions>
First, the conditions used for the simulation performed by the inventors will be described. FIG. 3 is a table summarizing the 14 conditions used in the simulations performed by the inventors. In FIG. 3, the number of systems represents the number of slot antennas 20 included in the antenna model. Between systems represents between adjacent slot antennas 20. 4 to 17 are diagrams showing the outline of the configuration of the antenna model in each of the conditions 1 to 14 shown in FIG. 4A to 17A are schematic views of the front of each antenna model. 4B to 17B are cross-sectional views at the BB position in FIGS. 4A to 17A, respectively. That is, FIG. 4 to FIG. 17B are cross-sectional views of each antenna model cut along a plane in which the tube longitudinal direction of the waveguide is orthogonal. In the simulation, the frequency used for the antenna was 76.5 GHz, which is a typical frequency used for millimeter wave radar. As an example, each antenna model is designed using a millimeter wave radar wavelength (λ = 3.92 mm) as a design wavelength.

  Specifically, the antenna model of condition 1 shown in FIGS. 3 and 4 has two slot antennas 20A and 20B. The length in the tube longitudinal direction of the waveguide 11 of each slot antenna 20 is 18.86 mm, the length in the width direction orthogonal to the tube longitudinal direction is 2.54 mm, and the interval between adjacent waveguides 11 (the slot antenna 20 The interval) is 3.85 mm (≈λ). Since the slot element 12 is disposed along the longitudinal direction of the waveguide 11, the length of the existing range in the longitudinal direction of the tube is within 18.86 mm. These sizes are common in the following conditions. Further, the antenna model of the condition 2 shown in FIGS. 3 and 5 has four slot antennas 20A to 20D. Neither the antenna model of condition 1 nor condition 2 has the groove 40 or the metal plate 50 described above. These conditions are used as a reference for comparing with the combination of the groove 40 and the metal plate 50 in other conditions.

  The antenna model of condition 3 shown in FIGS. 3 and 6 has two slot antennas 20A and 20B, and two grooves 40B are provided between the slot antennas 20A and 20B. The lengths of the two grooves 40B in the longitudinal direction of the waveguide 11 are both 20.86 mm. This length is common to the antenna models of the following conditions. The width of the two grooves 40B is 0.2 mm. The depths of the two grooves 40B are both 1.2 mm (≈ (3/10) λ). The two grooves 40B are provided at a distance of 0.4 mm (≈ (1/10) λ) with the straight line in the tube longitudinal direction of the waveguide 11 as the center line. The center line is at an equal position from the center line Cw of each of the slot antennas 20A and 20B. Further, the antenna model of condition 3 is provided with a metal plate 50A that is separated from the surface of the substrate 10 between the slot antennas 20A and 20B in the front direction. The length in the longitudinal direction of the waveguide 11 of the metal plate 50A is 20.86 mm. This length is common to the antenna models of the following conditions. The metal plate 50A is provided with a distance of 0.5 mm (= 0.128λ) in the front direction from the surface of the substrate 10. The metal plate 50A has a length in the front direction of 0.98 mm and a length in the width direction of 0.5 mm. The length in the longitudinal direction of the tube is longer than the length in the longitudinal direction of the tube in the range where the slot elements 12 are present, specifically, longer than 18.86 mm. The center line in the width direction of the metal plate 50A is at an equal position from the center line Cw of each of the adjacent slot antennas 20.

  The antenna model of condition 4 shown in FIGS. 3 and 7 has two slot antennas 20A and 20B. In addition to the two grooves 40B between the slot antennas 20A and 20B, Two grooves 40A and 40C are provided respectively. Each of the two grooves 40A, 40B, and 40C has a width of 0.3 mm (= 0.0765λ). Each of the two grooves 40A, 40B, and 40C has a depth of 1 mm (≈ (1/4) λ). Each of the two grooves 40A, 40B, and 40C is provided at a position where the gap between each adjacent slot antenna 20 and the waveguide 11 is 0.205 mm (≈ (1/20) λ). The two grooves 40B are provided at a distance of 0.3 mm (= 0.0765λ) with the straight line in the tube longitudinal direction of the waveguide 11 as the center line. The center line is at an equal position from the center line Cw of each of the slot antennas 20A and 20B.

  The antenna model under condition 5 shown in FIGS. 3 and 8 is obtained by removing the grooves 40A and 40C from the antenna model under condition 4 shown in FIGS. That is, the antenna model of condition 5 has two slot antennas 20A and 20B, and two grooves 40B are provided between the slot antennas 20A and 20B. The size of each part is the same as the size of each corresponding part of the antenna model of condition 4.

  The antenna model of condition 6 shown in FIGS. 3 and 9 has four slot antennas 20A to 20D, and two grooves 40B to 40D are provided between each of the slot antennas 20A to 20D. In addition, two grooves 40A and 40E are provided on both outer sides of the slot antennas 20A and 20D, respectively. The position and size of each groove 40 are the same as the size of each corresponding part of the antenna model of condition 4. Furthermore, the antenna model of condition 6 is provided with metal plates 50A to 50C that are separated from the surface of the substrate 10 between the slot antennas 20A to 20D in the front direction. In addition, metal plates 50 ′ and 50 ″ are provided on both outer sides of the slot antennas 20A and 20D. The position and size of each metal plate 50 is the same as the size of each corresponding part of the antenna model of Condition 3. The same.

  The antenna model of condition 7 shown in FIGS. 3 and 10 is obtained by removing the grooves 40A and 40C from the antenna model of condition 3 shown in FIGS. That is, the antenna model of condition 7 has two slot antennas 20A and 20B, and the metal plate 50A is provided in the front direction from the surface of the substrate 10 between the slot antennas 20A and 20B. The size of each part is the same as the size of each corresponding part of the antenna model of condition 3.

  Each of the antenna models under the conditions 8 to 11 shown in FIG. 3 and FIGS. 11 to 14 has two slot antennas 20A and 20B, and one groove 40B is provided between the slot antennas 20A and 20B. It has been. Conditions 8 and 9 have a common width of 1 mm (≈ (1/4) λ) of the groove 40B, and a depth of 1.2 mm (≈ (3/10) λ), 1 mm (≈ (1/4) λ). Conditions 9 to 11 have a common depth of 1 mm (≈ (1/4) λ) of the groove 40B, a width of 1 mm (≈ (1/4) λ), 0.3 mm (= 0.0765λ), 0 .5 mm (= 0.128λ). In any condition, the center line of the groove 40B is at an equal position from the center line Cw of each of the slot antennas 20A and 20B.

  The antenna model under condition 12 shown in FIGS. 3 and 15 is obtained by changing the size and position of the two grooves 40B in the antenna model under condition 5 shown in FIGS. That is, the widths of the two grooves 40B between the slot antennas 20A and 20B in the antenna model of condition 12 are both 0.2 mm. The two grooves 40B are provided at a distance of 0.4 mm (≈ (1/10) λ) with the straight line in the tube longitudinal direction of the waveguide 11 as the center line, and the center line is provided for each of the slot antennas 20A and 20B. It is at an equal position from the center line Cw. The gap between the groove 40B and each waveguide 11 of the adjacent slot antenna 20 is 0.255 mm. The depths of the two grooves 40B are both 1.2 mm (≈ (3/10) λ).

  Each of the antenna models under the conditions 13 and 14 shown in FIGS. 3, 16, and 17 has four slot antennas 20 </ b> A to 20 </ b> D, and is separated from the surface of the substrate 10 therebetween in the front direction. Metal plates 50A to 50C are provided. In addition, metal plates 50 'and 50 "are provided on both outer sides of the slot antennas 20A and 20D, respectively.

  The size and position of the metal plate 50 are different between the antenna model of condition 13 and the antenna model of condition 14. That is, referring to FIG. 16, the antenna model of condition 13 has metal plate 50 of the same size at the same position as the antenna model of condition 3 and the antenna model of condition 6. Specifically, in the antenna model of condition 13, the metal plate 50 is provided with a distance of 0.5 mm (= 0.128λ) in the front direction from the surface of the substrate 10. The length of the metal plate 50 in the front direction is 0.98 mm, and the length in the width direction is 0.5 mm. Referring to FIG. 17, in the antenna model of condition 14, the metal plate 50 is provided with a distance of 0.3 mm (= 0.0765λ) in the front direction from the surface of the substrate 10. The length of the metal plate 50 in the front direction is 0.2 mm, and the length in the width direction is 1 mm (≈ (1/4) λ). In any antenna model, the center line of the metal plate 50 is at an equal position from the center line Cw of each of the adjacent slot antennas 20.

<Reception strength simulation results>
18 to 31 are diagrams showing simulation results of reception strength by the antenna model in each condition represented by the conditions 1 to 14 in FIG. 3, respectively. In each figure, (A) is the simulation result of the reception intensity at each angle in the horizontal direction, (B) is the variation in the reception intensity at each angle in the horizontal direction between the slot antennas, and (C) is at each angle in the vertical direction. The reception strength simulation result of More specifically, in each figure, the horizontal axis represents the angle [° (deg)] from the antenna surface in the horizontal or vertical plane, and the vertical axis represents the received intensity [dB]. Note that the reception intensity of the isotropic antenna is set to 0 [dB]. An isotropic antenna refers to a fully omnidirectional antenna having a uniform three-dimensional radiation pattern.

  In addition, the direction in a simulation result is defined using FIG. The horizontal plane of the antenna refers to a horizontal plane in a case where the antenna is installed with the tube longitudinal direction of the waveguide being vertical, which is a general antenna installation state in a vehicle-mounted radar or the like. The arrow A direction in FIG. 38 is an angle in the + direction of directivity in the horizontal direction. That is, in the horizontal plane, the angle in the front direction of the antenna is set to 0 °, and the angle from the front of the antenna to the surface of the substrate 10 (+ 90 °) counterclockwise is set to the + direction angle of directivity. The arrow B direction in FIG. 38 is an angle in the minus direction of the directivity in the horizontal direction. That is, in the horizontal plane, an angle that reaches the surface of the substrate 10 in the clockwise direction (−90 °) is defined as an angle in the − direction of directivity. The arrow C direction in FIG. 38 is an angle in the + direction of directivity in the vertical direction. That is, in the vertical plane, the angle in the front direction of the antenna is set to 0 °, and the angle from the front of the antenna to the surface of the substrate 10 (+ 90 °) is set to the + direction angle of directivity. The arrow D direction in FIG. 38 is an angle in the negative direction of directivity in the vertical direction. That is, in the vertical plane, an angle until reaching the surface of the substrate 10 upward (−90 °) is defined as an angle in the − direction of directivity. When the antenna is thus installed, the radar detection angle generally refers to an angle that can be detected on the horizontal plane of the antenna. The detection angle may be expressed in both positive and negative directions in the horizontal plane with respect to the front surface of the antenna. 18 to 31 show simulation results at various angles ranging from 0 ° to ± 45 °. Here, the radar 300 is assumed to be a commonly used radar such as an in-vehicle radar. In this case, the radar 300 is considered to be important for detection performance within a range of 90 °, that is, ± 45 ° across the front (0 °) of the antenna.

  The simulation results of the reception intensity at each angle in the horizontal direction shown in FIGS. 18A to 31A represent the directivity of reception in the horizontal direction within a range of ± 45 ° in the antenna model. Further, the simulation result of the reception intensity at each angle in the vertical direction shown in (C) represents the directivity of reception in the vertical direction within a range of ± 45 ° in the antenna model.

  The directivity of the received intensity at each angle can be expressed using a beam width as an example of an index. The beam width is a range (angle) between the azimuth of the maximum value of the received intensity and the azimuth where the predetermined intensity (for example, 3 dB) decreases. The beam width increases as the received intensity directivity decreases. The detection angle of the radar equipped with the antenna increases as the beam width increases.

  The variation in the reception intensity at each angle in the horizontal direction shown in FIG. 18B to FIG. 31B is the reception intensity between the slot antennas at each angle in the horizontal direction within a range of ± 45 °. Difference. This represents a variation between horizontal directional slot antennas in a range of ± 45 °. In (B) of each figure, the first system indicates the slot antenna 20A, the second system indicates the slot antenna 20B,.

  In the radar 300 equipped with the antenna 100 including the plurality of slot antennas 20, the angle to the detection target is calculated based on the phase difference of the radio waves received by each of the plurality of slot antennas 20 included in the receiving antenna system. The Therefore, if the horizontal directivity between the slot antennas 20 varies, the angle calculation accuracy may deteriorate. Therefore, it can be said that the smaller the variation in the directivity in the horizontal direction between the slot antennas, the higher the accuracy of calculating the angle to the detected object, and the higher the detection performance of the radar 300 on which the antenna 100 is mounted.

  On the other hand, the reception strength simulation results at each angle in the horizontal direction show a symmetrical reception strength at a positive / negative angle around 0 ° with a peak at 0 ° in the range of ± 45 °. I can say that. However, there is a difference in the degree of variation in received intensity at each angle in the horizontal direction depending on conditions. Also, the degree of variation between slot antennas varies depending on conditions.

  FIG. 32 shows a value indicating the directivity of the horizontal reception intensity in each condition obtained from the reception intensity in the simulation using the antenna model of each condition represented by conditions 1 to 14 in FIG. It is the list showing the value showing the dispersion | variation degree between slot antennas. In the list shown in FIG. 32, the beam width in the horizontal direction of the antenna model in each condition is used as a value representing the directivity in the horizontal direction in each condition shown in FIG. In this simulation result, the beam width in the horizontal direction is from the simulation result of the received intensity at each angle in the horizontal direction shown in FIG. 18A to FIG. 31 to the direction where the maximum value of the received intensity is reduced by 3 dB. The angle is read out. The beam width in the horizontal direction of the antenna model under each condition is a statistical value obtained from the beam width for each slot antenna included in the antenna model under each condition. The statistical value is, for example, a minimum value. The statistical value may be a maximum value or an average value. In the list shown in FIG. 32, as a value indicating the degree of variation in directivity, the maximum difference in reception strength between slot antennas at each angle in the range of ± 45 ° of the antenna model under each condition. Value is used.

  In the list of FIG. 32, values representing the antenna gain in the antenna model of each condition and the isolation between the slot antennas included in the receiving antenna system are also shown. In this simulation result, the antenna gain is expressed as an absolute gain assuming that the reference antenna is an isotropic antenna. The antenna gain is obtained by reading the azimuth of the maximum value from the simulation result of the reception intensity at each angle in the horizontal direction shown in (A) of FIGS. The antenna gain in the antenna model for each condition is a statistical value obtained from the antenna gain for each slot antenna included in the antenna model for each condition. The statistical value is, for example, a minimum value. The statistical value may be a maximum value or an average value.

  When the antenna gain is high, the radio wave emitted from the antenna 100 reaches a long distance. For this reason, the distance that can be detected by the radar 300 on which the antenna 100 is mounted becomes longer. Therefore, it can be said that the detection performance of the radar 300 equipped with the antenna 100 is higher as the antenna gain is higher.

  In addition, the isolation in the antenna model of each condition is a statistical value obtained from the isolation between any two different slot antennas included in the antenna model of each condition. The statistical value is, for example, a minimum value. The statistical value may be a maximum value or an average value.

  If the isolation between the plurality of slot antennas included in the receiving antenna system is low, the received signals are mixed when calculating the angle to the detection target based on the phase difference of the received radio wave at each slot antenna The possibility increases. As a result, the angle calculation accuracy is lowered, and the detection accuracy is lowered. Therefore, it can be said that the detection performance of the radar 300 equipped with the antenna 100 is higher as the isolation is higher.

<Discussion>
Based on the list of results shown in FIG. 32, an effective antenna shape will be considered for each of the items of antenna gain, horizontal beam width, variation degree, and isolation under each condition.

(1) Consideration of effect of groove between slot antennas By comparing the simulation result in condition 1 with the simulation result in condition 9, there is no groove 40B in the antenna model having two slot antennas. The performance of the antenna can be compared between the case (condition 1) and the case (condition 9).

  Referring to FIG. 32, when there is a groove 40B between the slot antennas (condition 9), each of the items of antenna gain, horizontal beam width, horizontal directivity variation, and isolation is a groove. An effect is seen rather than the case where there is no 40B (condition 1). In particular, it can be said that the presence of the groove 20B is more effective with respect to the degree of variation in directivity in the horizontal direction and the isolation. Therefore, it has been verified that providing recesses such as grooves between a plurality of slot antennas included in the receiving antenna system is effective in improving the detection performance of the radar.

(2) Consideration of groove depth By comparing the simulation result in condition 8 with the simulation result in condition 9, in the antenna model having two slot antennas, the width of the groove 40B provided between them is 1 mm. Thus, it is possible to compare the reception strength characteristics of the antenna when the depth is 1.2 mm (condition 8) and when the depth is 1 mm (condition 9).

  Referring to FIG. 32, the antenna gain does not change under any condition, and the effect from the case where there is no groove 40B (condition 1) can be seen. The deeper groove 40B (condition 8) is more effective with respect to the degree of horizontal variation and the isolation (condition 8), and the shallower groove 40B (condition 9) is more effective with respect to the beam width. Therefore, it can be said that the difference in the depth of the groove used in this simulation does not greatly affect the performance of the antenna.

(3) Consideration about groove width By comparing the simulation results under conditions 9 to 11, in the antenna model having two slot antennas, the depth of the groove 40B provided between them is set to 1 mm, and the width Is 1 mm (Condition 9), 0.3 mm (Condition 10), and 0.5 mm (Condition 11).

  Referring to FIG. 32, the antenna gain and isolation are not greatly changed under any condition, and both are improved from the case where there is no groove 40B (condition 1). For the beam width, the wider groove condition (condition 9) is more effective, and for the horizontal variation degree, the wider groove condition (condition 9) does not contribute to the improvement of the effect, and the narrow groove width (condition). 10) has a great effect. Regarding the degree of variation in the horizontal direction, when the groove width is wide (condition 9), it is not shown that there is a significant effect from the case where there is no groove (condition 1). On the other hand, with respect to antenna gain, beam width, and isolation, although there are some differences between conditions 9-11, it is shown that there are significant effects from the case where there is no groove (condition 1). Yes. Therefore, focusing on the effect on the degree of variation in the horizontal direction, in the simulation under the present condition, it was verified that the narrower groove width is effective in improving the radar detection performance.

(4) Consideration about the number of grooves In the case where an antenna model having two slot antennas does not have a groove 40B between them by comparing simulation results under conditions 1, 5 and 10, (condition 1) It is possible to compare the case where there is one groove 40B having a width of 0.3 mm and a depth of 1 mm (condition 10) with the case where there are two grooves 40B of the same size (condition 5).

  Referring to FIG. 32, when compared with the simulation result under the conditions, the condition in which the groove 40B is provided (conditions 5 and 10) is the antenna, regardless of whether the groove 40B is one or two. Each of the items of gain, beam width, horizontal variation, and isolation is shown to be effective. When the number of grooves is compared, the smaller number of grooves (condition 10) is more effective with respect to the degree of horizontal variation, and the larger number of conditions (condition 5) is more effective with respect to other evaluation items. Therefore, in the simulation under the present conditions, it was verified that a larger number of grooves is more effective in improving radar detection performance.

(5) Consideration of the effect of grooves on both sides of the outside of the slot antenna By comparing the simulation result under the condition 4 with the simulation result under the condition 5, in an antenna model having two slot antennas, When there are two grooves 40A and 40C on each of the outer sides of the slot antennas 20A and 20B (condition 4) It can be compared with the case (Condition 5).

  Referring to FIG. 32, the antenna gain and the isolation are not greatly changed under any condition, and the effect from the case where there is no groove 40B (condition 1) is observed. The beam width is more effective when there are no grooves 40A and 40C on both sides of the slot antenna (Condition 5), and with respect to the horizontal variation, the grooves 40A and 40C are located on both sides of the slot antenna. (Condition 4) is highly effective. Therefore, depending on whether emphasizing the effect of widening the reception range of the antenna by widening the beam width or emphasizing the improvement in radar detection performance due to the degree of variation between horizontal directional slot antennas, It was verified that it was effective to improve the antenna performance by designing whether or not to further provide grooves on both sides of the slot antenna.

(6) Consideration about the effect of the plate member between the slot antennas By comparing the simulation result under the condition 1 and the simulation result under the condition 7, the metal plate 50A in the antenna model having two slot antennas is compared between the simulation result. The performance of the antenna can be compared between the case where there is no (condition 1) and the case where there is (condition 7).

  Referring to FIG. 32, the antenna gain and the degree of variation in the horizontal direction are not significantly affected by the provision of the metal plate 50A, and the beam width in the horizontal direction is provided with the metal plate 50A ( It is larger than the condition (condition 1) where there is no condition 7). The isolation is higher than the case (condition 1) where the metal plate 50A is not provided (condition 7). In particular, the isolation is greatly improved as compared with the case (condition 1) where there is no metal plate 50A (condition 7). Therefore, it is verified that the provision of a member such as the metal plate 50 between a plurality of slot antennas included in the receiving antenna system is effective in improving the radar detection performance particularly from the viewpoint of improving the isolation. It was done.

(7) Consideration on size of plate member By comparing the simulation result under condition 13 with the simulation result under condition 14, in an antenna model having four slot antennas, metal plates 50A on both sides between and outside the antenna model ˜50C, 50 ′, 50 ″ in common, and when the narrow metal plate 50 is installed at a position far from the antenna surface (condition 13), the wide metal plate 50 is installed at a position near the antenna surface. Antenna performance (condition 14) can be compared.

  Referring to FIG. 32, the antenna gain and the horizontal variation degree are smaller when the wide metal plate 50 is disposed (condition 14). Regarding the isolation, it is higher when the wide metal plate 50 is disposed (condition 14). With respect to the beam width, the effect of placing the narrow metal plate 50 (condition 13) is greater. In particular, with respect to isolation, the case where the metal plate 50 is not installed (condition 13) in the case where the wide metal plate 50 is arranged (condition 14) than the case where the narrow metal plate 50 is arranged (condition 13) (conditions). From 2) it is shown to be larger. Therefore, providing a member such as a plate member between the plurality of slot antennas included in the receiving antenna system is effective in improving the detection performance of the radar, particularly when attention is focused on improving isolation. It has been verified that a wider member such as a plate member is more effective in improving antenna performance.

(8) Consideration about combination of groove and plate member I
By comparing the simulation results of condition 3, condition 7 and condition 12, in the case of an antenna model having two slot antennas, two grooves 40B and a metal plate 50A are arranged between them (condition 3) When only the metal plate 50A is disposed excluding the groove 40B from the condition 3 (condition 7), and when only the groove 40B is disposed excluding the metal plate 50A from the condition 3 (condition) It is possible to compare the antenna performance with 12).

  Referring to FIG. 32, when the simulation result under condition 3 is compared with the simulation result under condition 7, the case where both the two grooves 40B and the metal plate 50A are arranged between the slot antennas (condition 3). However, each of the items of antenna gain, horizontal beam width, horizontal variation, and isolation is more effective than when groove 40A is not disposed (condition 7). The effect is higher than when both of the plates 50A are not arranged (condition 1). Comparing the simulation result under condition 3 and the simulation result under condition 12, the antenna gain is more effective when the metal plate 50A is not disposed (condition 12), but the horizontal beam width and the horizontal direction are more effective. Regarding the degree of variation and isolation, the case where both the two grooves 40B and the metal plate 50A are arranged between the slot antennas (condition 3) is more than the case where the metal plate 50A is not arranged (condition 12). High effect. In particular, regarding the degree of horizontal variation and isolation, the case where both the groove 40B and the metal plate 50A are arranged between the slot antennas (condition 3) is not installed (conditions 7 and 12). The effect is greater than when neither is installed (Condition 1). Therefore, providing a combination of a concave portion such as a groove and a member such as a plate member between the slot antennas improves the radar detection performance compared to the case where none or only one of them is provided. It was verified that it was effective.

(9) Consideration on the combination of grooves and plate members II
By comparing the simulation result in condition 6 with the simulation result in condition 13, in the antenna model having four slot antennas, the metal plates 50A to 50C, 50 ′, 50 ″ on both sides in the middle and outside are shared. Thus, the performance of the antenna can be compared between the case where there are two grooves 40 </ b> A to 40 </ b> E between the slot antennas and on both sides on the outer side (condition 6).

  Referring to FIG. 32, the antenna gain is obtained when both of the grooves 40A to 40E and the metal plates 50A to 50C, 50 ′, and 50 ″ are arranged between the slot antennas and on both outer sides thereof (condition 6). The horizontal beam width, the horizontal variation degree, and the isolation items are all more effective than the case where only the metal plates 50A to 50C, 50 ′, and 50 ″ are arranged (Condition 13). In addition, the effect is higher than when both the groove 40 and the metal plate 50 are not disposed (condition 2). In particular, with respect to the isolation, the direction in which the groove 40 and the metal plate 50 are disposed between the slot antennas and on both sides outside the slot antenna (condition 6) is more than the case in which the groove 40 is not installed (condition 13). A great effect is exhibited from the case where none of them is installed (condition 2). Therefore, providing a combination of a concave portion such as a groove and a member such as a plate member between the slot antennas improves the radar detection performance compared to the case where none or only one of them is provided. It was verified that it was effective.

<Summary>
As a result of the above simulation, the antenna 100 includes a plurality of slot antennas as a receiving antenna system, and a groove 40 or the like is provided between the surface of the adjacent first slot antenna and the surface of the second slot antenna. One or more recesses are configured. The one or more recesses may be two or more grooves. By adopting this configuration for the antenna 100, the antenna gain is improved, the beam width in the horizontal direction is increased, the degree of variation in the horizontal reception intensity between the slot antennas is reduced, and the isolation between the slot antennas is increased. Has the effect of increasing.

  Similarly, the antenna 100 includes a plurality of slot antennas as a receiving antenna system, and is a positive distance in the front direction of the antenna between the surface of the adjacent first slot antenna and the surface of the second slot antenna. It is assumed that a conductor member such as the metal plate 50 is provided at a position having the. The antenna 100 having this configuration has an effect of increasing the horizontal beam width and increasing the isolation between the slot antennas.

  Further, the antenna 100 may be configured to include both one or more recesses such as the groove 40 and a conductor member such as the metal plate 50.

  Note that concave portions such as the grooves 40 and conductor members such as the metal plate 50 may be further provided on both sides outside the plurality of slot antennas.

  Preferably, in the antenna 100, the interval between the adjacent first slot antenna and the second slot antenna is 1.5λ (λ: wavelength of the used frequency of the antenna 100) or less. More preferably, the interval between the adjacent first slot antenna and the second slot antenna is 1.0λ or less. Thereby, the detection angle of the radar 300 can be made wider.

  Even in this case, the gap between the first slot antenna and the second slot antenna is preferably (1/20) λ or more. By doing so, it becomes easy to arrange a recess such as the groove 40 or a member such as the metal plate 50 between the adjacent slot antennas.

  With the antenna 100 having such a configuration, it is possible to suppress a decrease in isolation even when the interval between the slot antennas is narrowed. Therefore, the detection angle can be made wider without reducing the detection accuracy of the radar 300.

  From the simulation results of the inventors, it has been found that the detection performance of the radar 300 is improved in the range of at least ± 45 ° as compared with the antenna not having the above configuration by setting the antenna 100 to the above configuration. Therefore, by mounting the antenna 100 having the above configuration, the detection angle of the radar 300 can be set to a range of at least ± 45 °. Preferably, the detection angle of the radar 300 can be set to a range of at least ± 20 ° from the simulation results under the conditions shown in FIGS.

[Second Embodiment]
In the above example, the first member of the conductor existing in front of the surface of the substrate 10 between the adjacent slot antennas is disposed in front of the surface of the substrate 10 without being in contact with the surface of the substrate 10. A metal plate 50 is illustrated. It is shown by simulations by the inventors that the detection performance of the radar 300 is improved by such an arrangement. It is sufficient that at least a part of this member is present in front of the surface of the substrate 10. Therefore, the inventors have described the antenna model under the condition 15 in which the metal plate 50 is arranged such that a part is present in front of the surface of the substrate 10 and the other part is present in the back direction from the surface. A similar simulation was performed.

  FIG. 33 is a diagram showing an outline of the configuration of the antenna model under condition 15, and is a schematic cross-sectional view of the antenna model cut along a plane perpendicular to the tube longitudinal direction of the waveguide. In the antenna model of condition 15 shown in FIG. 33, for example, a metal plate having a rectangular cross section that is long in the front direction between the slot antennas 20A and 20B is different from the antenna model of condition 9 shown in FIGS. Be placed. The length of the metal plate in the front direction is longer than the depth of the groove 40B, and the length in the width direction is shorter than the width of the groove 40B. About half of the length of the metal plate in the front direction is included in the groove 40B, and the bottom side thereof is disposed at a position farther in the front direction than the bottom surface of the groove 40B.

  When a similar simulation was performed using the antenna model of condition 15, the antenna gain was 14.1 [dB], the horizontal beam width was 70.4 [deg], and the isolation was 17.5 [deg]. there were. By comparing this result with the simulation result in condition 9, when a metal plate whose part in the height direction is located in the back direction with respect to the surface of the substrate (condition 15), the metal plate is The antenna performance can be compared with the case where the antenna is not arranged (condition 9).

  Referring to the simulation result and FIG. 32, the horizontal beam width is more effective when the metal plate is arranged as described above (condition 15), and the metal plate and the groove 40 are provided. The effect is greater than when not (condition 2). Therefore, from the viewpoint of the beam width in the horizontal direction, even if a part of the front direction is located behind the surface of the substrate, it is necessary to provide a member such as a metal plate that exists in front of the surface of the substrate. It has been verified that it is effective in improving the detection performance of.

[Third Embodiment]
When two or more grooves 40 are provided on the antenna surface between adjacent slot antennas 20, at least one of the plurality of grooves 40 may communicate with each other. That is, the conductor which is a member of the substrate 10 existing as the first partition between the two adjacent grooves 40 does not exist between the two grooves 40 in the at least one place. Forty spaces may be configured to be continuous at one place. For example, in the antenna model of condition 5, at least one groove 40B provided on the surface of the substrate 10 between the adjacent slot antennas 20A and 20B may be communicated at least at one location.

  The inventors formed two grooves 40B on the surface of the substrate 10 between the slot antennas 20A and 20B, and the antenna model of condition 16 in which the two grooves 40B communicate with each other in one place. A simulation similar to the above was performed. The antenna model of condition 16 has the same form as the state in which the metal plate included in the antenna model of condition 15 shown in FIG. 33 does not exist in the front direction than the surface of the substrate 10 and exists only in the back direction. It is.

  When a similar simulation was performed using the antenna model of condition 16, the antenna gain was 16.0 [dB], the horizontal beam width was 59.2 [deg], and the isolation was 24.1 [deg]. there were. By comparing this result with the simulation result under the condition 5, the performance of the antenna is compared with the case where the part of the two grooves 40A is in communication (condition 16) and the case where it is not (condition 5). Can do.

  Referring to the simulation result and FIG. 32, there is no significant difference between the case where a part of the two grooves 40B communicates with each evaluation item (condition 16) and the case where no condition (condition 5). The case (conditions 5 and 16) also shows a greater effect than the case where the groove 40 is not provided (condition 2). Therefore, even when at least one place is connected in the back direction from the surface of the substrate 10, it is possible to provide one or more recesses such as grooves on the surface of the substrate 10 between adjacent slot antennas. It has been verified that it is effective in improving the detection performance of. Therefore, when manufacturing the antenna 100 by a manufacturing method in which it is easier to communicate at least one recess such as the groove 40 in the back direction from the surface of the substrate 10, the recess has such a shape. Thus, the antenna 100 can be easily formed.

[Fourth Embodiment]
The manufacturing method of the antenna 100 mounted on the radar 300 is not limited to a specific manufacturing method. However, as described above, the interval between adjacent slot antennas 20 is, for example, 1.5λ or less, preferably 1.0λ or less, and the gap between adjacent slot antennas 20 is (1/20) λ or more at that interval. . Thus, it is necessary to arrange one or more grooves 40 and plate portions 50 in the gap between adjacent slot antennas 20. Furthermore, it has been verified in the simulation under the present conditions that the number of grooves 40 is larger and the narrower one is more effective in improving the radar detection performance. Therefore, depending on the wavelength of the operating frequency of the antenna 100, it may be difficult to cut and form the groove 40 from the surface of the substrate 10. Therefore, the antenna 100 is preferably manufactured by a manufacturing method in which a plurality of plates called diffusion bonding or heat pressure welding are stacked and further pressure-bonded. That is, preferably, the substrate 10 has a laminated structure in which a plurality of plates are laminated. In addition, the board in a state before lamination is also referred to as a laminated board in the following description.

  FIG. 34 is a diagram for explaining an example of a method for manufacturing the antenna 100. FIG. 34A is a diagram showing a laminated plate in a schematic cross-sectional view of the antenna 100 cut along a plane in which the tube longitudinal direction of the waveguide is orthogonal. FIG. 34B is a diagram for explaining the shape of each laminated plate, and is a view of each laminated plate as viewed from the front direction of the antenna 100.

  Referring to FIG. 34 (A), when groove 40B is provided between adjacent slot antennas 20A and 20B, antenna 100 stacks stacked plates T1 to T4 parallel to the surface of substrate 10 in that order. And further formed by pressure contact. The thickness of each laminate is determined so that the cross sections of the surfaces parallel to the surface of the substrate 10 have the same shape. Specifically, referring to FIG. 34A, the thickness of the laminated plate T1 is the length Th1 in the front direction of the antenna 100 from the bottom surface of the substrate 10 to the bottom surface of the waveguide 11. The thickness of the laminated plate T2 is the length Th2 in the front direction of the antenna 100 from the bottom surface of the waveguide 11 to the bottom surface of the groove 40B. The thickness of the laminated plate T3 is the length Th3 in the front direction of the antenna 100 from the bottom surface of the groove 40B to the bottom surface of the slot element 12. The thickness of the laminated plate T4 is the length Th4 in the front direction of the antenna 100 from the bottom surface of the slot element 12 to the surface of the substrate 10. In addition, thickness Th3, Th4, etc. of laminated board T3, T4 etc. may be implement | achieved so that a thin board of the same shape may be piled up and it may become required thickness.

  By setting the thicknesses Th1 to Th4 of the laminated plates T1 to T4 in this way, the laminated plates T1 to T4 have a shape as shown in FIG. That is, the laminated plate T1 is a plate that has not been subjected to hole machining. The laminated plate T2 has through holes H1 and H2. The through holes H1 and H2 have a cross-sectional shape (rectangular shape) in a plane parallel to the surface of the substrate 10 of each of the waveguides 11A and 11B. The laminated plate T3 has through holes H1 and H2 and a through hole H3. The through hole H3 has a cross-sectional shape (rectangular shape) in a plane parallel to the surface of the substrate 10 of the groove 40B. The laminated plate T4 has a through hole H3 and a plurality of through holes H4. The through hole H <b> 4 has a cross-sectional shape (rectangular shape) in a plane parallel to the surface of the substrate 10 of the slot element 12.

  The through holes H1 and H2 of the laminated plate T2 are closed by the laminated plate T1 in the back direction. Further, the through holes H1 and H2 of the laminated plate T2 communicate with the through holes H1 and H2 of the laminated plate T3 in the front direction. The through hole H3 of the laminated plate T3 is closed by the laminated plate T2 in the back direction. Further, the through hole H3 of the laminated plate T3 communicates with the through hole H3 of the laminated plate T4 in the front direction.

  As shown in FIG. 34B, a complicated element such as the slot element 12 and the groove 40 is laminated by adopting a manufacturing method of the antenna 100 called diffusion bonding, in which a laminated plate is crimped. The plate can be formed as a through hole. Therefore, it can be manufactured more easily than cutting them out from the surface of the substrate 10. In particular, when the wavelength of the operating frequency of the antenna 100 is a small wavelength such as a millimeter wave, it is very difficult to cut out the groove 40. Therefore, by adopting such a manufacturing method, it is possible to facilitate the formation of the antenna, particularly when the wavelength of the operating frequency is small.

  As described in the third embodiment, even when the two grooves 40 communicate with each other in the back direction with respect to the surface of the substrate 10, by adopting the above-described manufacturing method called diffusion bonding, It can be formed easily.

  FIG. 35 is a diagram for explaining a method of manufacturing the antenna 100 in this case. That is, FIG. 35 shows a case where two grooves 40B are provided between adjacent slot antennas 20A and 20B, and these two grooves 40B are partially connected in the back direction from the surface of the substrate 10. It is a figure for demonstrating this manufacturing method. Referring to FIG. 35, antenna 100 is formed by laminating laminated plates T1, T2, T31, T32, and T4 parallel to the antenna surface in this order and further press-contacting them. Specifically, referring to FIG. 35A, the thickness of laminated plate T1 is the length Th1 in the front direction of antenna 100 from the bottom surface of substrate 10 to the bottom surface of waveguide 11. The thickness of the laminated plate T2 is the length Th2 in the front direction of the antenna 100 from the bottom surface of the waveguide 11 to the bottom surfaces of the two grooves 40B. The thickness of the laminated plate T31 is the length Th31 in the front direction of the antenna 100 from the bottom surface of the two grooves 40B to the position where the connection of the two grooves 40B ends. The thickness of the laminated plate T32 is the length Th32 in the front direction of the antenna 100 from the position where the connection of the two grooves 40B is completed to the bottom surface of the slot element 12. The thickness of the laminated plate T4 is the length Th4 in the front direction of the antenna 100 from the bottom surface of the slot element 12 to the surface of the substrate 10.

  By setting the thicknesses Th1, Th2, Th31, Th32, Th4 of the laminated plates T1, T2, T31, T32, T4 in this way, the thicknesses of the laminated plates T1, T2, T31, T31 are set in this way. , T32 and T4 have the shapes shown in FIG. That is, the laminated plate T1 is a plate that has not been subjected to hole machining. The laminated plate T2 has through holes H1 and H2. The through holes H1 and H2 have a cross-sectional shape (rectangular shape) in a plane parallel to the surface of the substrate 10 of each of the waveguides 11A and 11B. The laminated plate T31 has through holes H1 and H2 and a through hole H5. The through hole H5 has a cross-sectional shape (rectangular shape) in a plane parallel to the surface of the two grooves 40B and the communication portion. The laminated plate T32 has through holes H1 and H2 and through holes H6 and H7. The through holes H6 and H7 have a cross-sectional shape (rectangular shape) on each of the two grooves 40B in a plane parallel to the surface of the substrate 10. The laminated plate T4 has through holes H6 and H7 and a plurality of through holes H4. The through hole H <b> 4 has a cross-sectional shape (rectangular shape) in a plane parallel to the surface of the substrate 10 of the slot element 12.

  The through holes H1 and H2 of the laminated plate T2 are closed by the laminated plate T1 in the back direction. Further, the through holes H1 and H2 of the laminated plate T2 communicate with the through holes H1 and H2 of the laminated plate T31 and the laminated plate T32 in the front direction. The through hole H5 of the laminated plate T31 is closed by the laminated plate T2 in the back direction. Of the through hole H5 of the laminated plate T31, the hole region corresponding to the communicating portion of the two grooves 40B is closed by the laminated plate T32 in the front direction. Of the through hole H5 of the laminated plate T31, the hole region corresponding to the two grooves 40B communicates with the through holes H6 and H7 of the laminated plate T32 and the laminated plate T4 in the front direction.

  By adopting a manufacturing method of the antenna 100 called diffusion bonding, in which plates are stacked and further crimped, the grooves 40 as described in the third embodiment communicate with each other inside. 35B, the communication portion and the location where the two grooves 40B are separated by the partition walls are formed in different laminated plates with shapes corresponding to each other. It can be formed as a through hole. Therefore, even a complicated shape that cannot be generated by being cut out from the surface of the substrate 10 as described above can be easily formed by adopting this manufacturing method.

  The communicating portion may be on the front side of the bottom of the groove 40. In this case, the laminate is separated by a laminate having two through holes that form from the bottom of the groove 40 to the communicating portion, a laminate having a through hole that forms the communicating portion, and a partition wall portion on the front side of the communicating portion. In addition, a laminated plate having two through holes for forming two grooves 40B may be used.

[Fifth Embodiment]
In the above example, one or more grooves 40 extending in the longitudinal direction of the waveguide 11 are illustrated as one or more recesses formed on the surface of the substrate 10 between the adjacent slot antennas 20. The groove 40 may be a region on the surface of the substrate 10 between the surfaces of two adjacent slot antennas, and may be formed at a position where at least one slot element 12 exists in the width direction. That is, the groove 40 extending in the tube longitudinal direction of the waveguide 11 may be interrupted in the tube longitudinal direction. In other words, two or more grooves 40 extending in the tube longitudinal direction of the waveguide 11 may be provided in parallel in the tube longitudinal direction across the second partition wall. The second partition wall portion does not exist at a position where the slot elements 12 of two adjacent slot antennas are present on either side in the width direction, and exists at a position where there is no slot element 12 on either side. To do.

  This is because the effect of improving the isolation by providing a recess such as the groove 40 is seen from the results of the inventors' verification test, so the recess affects the other of the received signals in the adjacent slot antenna 20. It can be said that there is an effect of suppressing. Therefore, it is considered that the above-described effect can be obtained by forming the concave portion at a position adjacent to the slot element 12 which is an element that receives at least the radar wave of the slot antenna 20.

FIG. 36 is a diagram for explaining another example of the groove 40 provided between adjacent slot antennas 20. Referring to FIG. 36, as an example, in slot antenna 20, slot element 12 is located directly above each of two straight lines C _SL and C _SR whose centers are parallel to each other across center line Cw of slot antenna 20. They are arranged at equal intervals in the longitudinal direction of the waveguide 11 so as to be positioned. The slot elements 12 arranged on the straight line C _SL, the width direction position of the slot elements 12 arranged on a straight line C _SR does not match. As shown in FIG. 36, the straight lines H _T and H _B are the straight lines perpendicular to the longitudinal direction of the tubes, which are in contact with both ends of the longitudinal direction of each slot element 12. Referring to FIG. 36, the region extending in the width direction and continuous in the longitudinal direction of the tube, which is divided by the adjacent straight line H _T and straight line H _{B on} the surface of the substrate 10, includes a region including the slot element 12. The areas not included are alternated. The region including the slot element 12 and the region not including the slot element 12 are also shown in FIG.

The groove 40B provided between the slot antennas 20A and 20B forms a groove in the region including the slot element 12 in the width direction. The portion of the groove 40B that is interrupted in the longitudinal direction of the tube, that is, the second partition wall portion exists in a region that does not include the slot element 12 in the width direction, and does not exist outside the region. In the example of FIG. 36, the slot element 12 exists in a region between the slot antennas 20A and 20B, which is divided by a straight line H _T and a straight line H _B adjacent to the straight line in FIG. The slot element 12 does not exist in a region defined by the straight line H _B and the straight line H _T adjacent to the straight line in FIG. Therefore, the groove 40B always exists in the former region. The interrupted portion of the groove 40B, which is the second partition wall portion, exists in the latter region, and does not exist in a range exceeding the region.

  By providing the location where the groove 40 is interrupted, that is, the second partition wall portion, the strength of the antenna 100 in the longitudinal direction of the tube can be prevented from decreasing.

[Sixth Embodiment]
For example, the member provided at a position having a positive distance in the front direction from the surface of the substrate 10 between the adjacent slot antennas 20 such as the metal plate 50 is also at least from the surface of the substrate 10 at a position adjacent to the slot element 12. May be provided above. In addition, the attachment method with respect to the board | substrate 10 of this member is not limited to a specific method. Therefore, as an example, a support portion for supporting the metal plate 50 against the surface of the substrate 10 may be provided at a position not adjacent to the slot element 12 on the surface of the substrate 10, and the metal plate 50 may be attached to the substrate 10.

  FIG. 37 is a view for explaining a method of attaching using a support portion as an example of a method of attaching the metal plate 50 to the substrate 10. FIG. 37A is a diagram of the antenna 100 as viewed from the front, and FIG. 37B is a schematic diagram of a cross section of the antenna 100 at the CC position in FIG. 37A.

  Referring to FIG. 37A, the metal plate 50A extending in the tube longitudinal direction of the waveguide 11 does not include the slot 12, and the support for supporting the metal plate 50A with respect to the surface of the substrate 10 is provided. A part 50A ′ is provided. Referring to FIG. 37 (B), support portion 50A 'is a columnar member extending from the surface of substrate 10 toward metal plate 50A, for example.

  The position where the support portion 50A 'is provided is the same as the position of the second partition wall portion provided in the groove 40B described in the fifth embodiment. That is, the support portion 50A 'is not provided at a position where the slot elements 12 of two adjacent slot antennas are present on either side in the width direction, and is provided at a position where the slot elements 12 are not present on either side. This is because, from the results of the verification tests by the inventors, an effect such as improvement in isolation can be seen by providing a member such as the metal plate 50, so that the member is applied to the other of the received signals in the adjacent slot antenna 20. It can be said that there is an effect of suppressing the influence. Therefore, the metal plate 50 is installed at least at a position adjacent to the slot element 12 which is an element that receives the radar wave of the slot antenna 20, and the support portion 50 A ′ that may affect the effect is provided on the slot element 12. This is because it is considered that the above-described effect is easily obtained when the positions are not adjacent to each other.

The support portion 50A ′ exists in a region that does not include the slot element 12 in the width direction, and does not exist outside that region. In the example of FIG. 37, the slot element 12 exists in an area between the slot antennas 20A and 20B, which is divided by the straight line H _T and the straight line H _B adjacent below the straight line in FIG. The slot element 12 does not exist in a region partitioned by the straight line H _B and the straight line H _T adjacent below the straight line in FIG. Accordingly, the support portion 50A ′ is provided in the latter area and is not provided in a range exceeding the area.

  The support portion 50A 'may be formed integrally with the metal plate 50A. By forming in this way, the metal plate 50A can be easily joined to the antenna 100 manufactured by, for example, diffusion joining.

  The support portion 50 </ b> A ′ may be formed integrally with the substrate 10. Furthermore, the support portion 50 </ b> A ′ may be formed integrally with the metal plate 50 </ b> A and the substrate 10. In this case, the support portion 50 </ b> A ′ or the support portion 50 </ b> A ′ and the metal plate 50 </ b> A can be manufactured together with the substrate 10 by diffusion bonding. When the support portion 50A ′ or the support portion 50A ′ and the metal plate 50A are manufactured together with the substrate 10 by diffusion bonding, the laminated plates T1 to T4 shown in FIG. Laminate sequentially. Referring to FIG. 37, in the front direction from the laminated plate T1 that forms the surface of the substrate 10, a laminated plate T5 for forming the support portion 50A ′ and a laminated plate T6 for forming the metal plate 50A are provided. Are further laminated. The laminated plate T5 includes a region having a cross-sectional shape in a plane parallel to the surface of the substrate 10 of the support portion 50A 'as a region for forming the support portion 50A'. In addition, the laminated plate T5 has a hole region having a cross-sectional shape equal to or larger than that of the slot element 12 on a plane parallel to the surface of the substrate 10. This hole region communicates with a through-hole formed in the slot element 12 provided in the laminated plate adjacent to the laminated plate T5 in the back direction. By manufacturing the support portion 50A ′ or the support portion 50A ′ and the metal plate 50A together with the substrate 10 by diffusion bonding, the metal plate is stably supported with respect to the substrate 10 and the antenna 100 having the metal plate is manufactured. Becomes easier.

[Seventh Embodiment]
As defined above, the antenna system is composed of one or more slot antenna groups arranged, and in the above embodiment, one antenna system is composed of one slot antenna. An example is shown. Therefore, in the case of a receiving antenna system, the angle of the object to be detected with respect to the antenna 100 is calculated based on the phase difference of the received radio wave for each slot antenna as the phase difference of the radio wave received for each antenna system. Is done.

  As another example, one antenna system may be configured by a plurality of slot antennas. As an example of the antenna 100 according to the seventh embodiment, FIG. 39 shows a configuration of the antenna 100 in which one antenna system includes three slot antennas. In the example of FIG. 39, the transmission antenna system is composed of three slot antennas 20E, 20F, and 20G. The three slot antennas 20E, 20F, and 20G have waveguides 11E, 11F, and 11G, respectively, and are arranged so that the longitudinal directions of the waveguides 11E, 11F, and 11G are parallel to each other. The three slot antennas 20E, 20F, and 20G are connected to the transmitter 150.

  Transmitter 150 and receiver 170 and the slot antenna are connected by an independent feeder for each antenna system. In FIG. 1, since one antenna system is composed of one slot antenna, four feed lines connecting each of the four slot antennas and the receiver 170 are typically one line. However, FIG. 39 specifically shows a power supply line that connects each slot antenna to the transmitter 150 and the receiver 170. In detail, referring to FIG. 39, in the (four) receiving antenna system constituted by one slot antenna, each slot antenna 20A to 20D is connected to receiver 170 by an independent feeder. ing. In the transmission antenna system constituted by the three slot antennas 20E, 20F, and 20G, one feed line extending from the transmitter 150 is branched into three, and the slots are respectively connected to the slot antennas 20E, 20F, and 20G. Connected.

  Based on the above simulation, grooves 40G and 40H may be formed between the slot antenna 20E and the slot antenna 20F and between the slot antenna 20F and the slot antenna 20G. Also, grooves 40F and 40I may be provided on both sides (outside) of the slot antenna 20E and the slot antenna 20G that are not adjacent to the slot antenna 20F (outside). Further, instead of the grooves 40G to 40I or in addition to the grooves 40G to 40I, a metal plate (not shown) may be provided as in the above embodiment.

  The transmission wave transmitted from the transmitter 150 is distributed by the feeder line and radiated from the waveguides 11E, 11F, and 11G. The radio waves radiated from the waveguides 11E, 11F, and 11G are received by the adjacent slot antennas.

  When the isolation is low (bad), the radio waves received by the slot antennas 20E, 20F, and 20G increase, and the received radio waves return to the transmitter 150. For this reason, the efficiency of radio wave radiation is deteriorated. However, grooves 40G and 40H are formed between the slot antenna 20E and the slot antenna 20F and between the slot antenna 20F and the slot antenna 20G, respectively, so that the slot antennas 20E and 20F and the slot antenna 20F are formed. And 20G is improved. Therefore, the amount of transmission radio waves from the transmitter 150 returning to the transmitter 150 via the adjacent antenna can be suppressed. As a result, the efficiency of transmission of radio waves by the transmitter 150 is improved. In general, this is said to improve the VSWR characteristic (Voltage Standing Wave Ratio: a characteristic value indicating the return amount of radio waves).

[Eighth Embodiment]
As another example of the antenna 100, dummy slot antennas may be further arranged on both sides outside the slot antenna 20 arranged in parallel. As an example of the antenna 100 according to the eighth embodiment, FIG. 40 shows one dummy slot antenna DU1, one on each of the outer sides of the four slot antennas 20A to 20D constituting the receiving antenna system. An antenna 100 in which DU2 is arranged is shown. Note that grooves 40 may be provided on both outer sides of the slot antennas DU1 and DU2.

  By providing dummy slot antennas DU1 and DU2 on both sides of the plurality of parallel slot antennas 20A to 20D, it is possible to further improve the matching of the characteristics of the slot antennas and to improve the symmetry of the antenna directivity. Can be improved.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

11, 11A-11G Waveguide 12 Slot element 20, 20A-20G Slot antenna 40, 40A-40I Groove 50, 50 ', 50 ", 50A-50C Metal plate 50A' Supporting part 100 Antenna 300 Radar T1-T6, T31 , T32 laminate

Claims (13)

A first slot antenna;
A second slot antenna provided apart from the first slot antenna,
A surface between the first slot antenna and the second slot antenna, which is a surface on which a slot element of the first slot antenna is formed, and in front of the surface of the second slot antenna. An antenna provided with a first member of a conductor. The first slot antenna and the second slot antenna are arranged side by side in a first direction,
Of the two sides in the first direction as viewed from the first slot antenna, the second slot antenna is arranged on one side, and no other slot antenna is arranged on the other side.
The antenna according to claim 1, wherein a second member made of a conductor is provided on the other side in front of the surface of the first slot antenna. The first slot antenna and the second slot antenna are arranged side by side in a first direction,
The first slot antenna and the second slot antenna each have a plurality of slot elements arranged along a second direction orthogonal to the first direction. antenna. The antenna according to any one of claims 1 to 3, wherein an interval between the first slot antenna and the second slot antenna is 1.5λ (λ: wavelength of a frequency used by the antenna) or less. The antenna according to claim 4, wherein a gap between the first slot antenna and the second slot antenna is equal to or greater than (1/20) λ. The antenna according to any one of claims 1 to 5, wherein the first member is provided in front of the surfaces of the first slot antenna and the second slot antenna. A substrate on which the first slot antenna and the second slot antenna are formed;
The substrate has a first surface forming a surface of the first slot antenna and a surface of the second slot antenna;
The antenna according to claim 1, wherein the first member is provided in front of the first surface. The first slot antenna and the second slot antenna are arranged side by side in a first direction,
A support portion for supporting the first member with respect to the first surface of the substrate;
At the position where at least one of the slot element of the first slot antenna and the slot element of the second slot antenna is formed in either of the first directions when viewed from the support part, the support part is Not provided,
The support portion is provided at a position where neither the slot element of the first slot antenna nor the slot element of the second slot antenna is formed in any of the first directions when viewed from the support portion. The antenna according to claim 7. The substrate has a laminated structure in which a plurality of plates are laminated,
The plurality of plates include a first plate having the first surface, and a second plate disposed in front of the first surface,
The first plate has a first through hole that forms the slot element;
9. The antenna according to claim 8, wherein the second plate communicates with the first through hole, and has a second through hole larger than the first through hole and a region forming the support portion. . The first slot antenna and the second slot antenna are arranged side by side in a first direction,
The said 1st member is a metal plate provided in the said 1st surface of the said board | substrate, and extended in the 2nd direction orthogonal to the said 1st direction. antenna. The antenna according to any one of claims 1 to 10, wherein the first member is provided at an equal position from the first slot antenna and the second slot antenna. A radar equipped with the antenna according to claim 1. The radar according to claim 12, wherein a detection angle is ± 20 ° or more.

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