JP2018182557A - Horn antenna and horn antenna array - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a horn antenna and a horn antenna array which are arranged to be able to direct an antenna directional beam toward a direction deviated from a front direction to sense the presence and bearing of a target present which is in a direction deviated from a front direction.SOLUTION: In a horn antenna, a central axis of a horn is not perpendicular to a plane of an opening of a horn, and the connection of the horn with a wave guide is changed in position. So, a beam direction can be inclined. The beam direction can be adjusted by a shape of the horn and a state of connection with the wave guide. Therefore, disposing two horn antennas identical to the horn antenna hereof in front of a substrate, adjusting a beam direction and adopting a monopulse angular measurement system, the presence and bearing of a target can be sensed in wide angle.SELECTED DRAWING: Figure 4

Description

  The present disclosure relates to technology for detecting the presence and orientation of a target at a wide angle.

  Patent Documents 1 to 4 disclose techniques for detecting the presence of a target at a wide angle. In Patent Document 1, the presence of a target in the front direction is detected using a planar antenna formed on the substrate plane, and the presence of a target in the lateral direction is detected using an electromagnetic wave reflection surface formed on the side surface of the substrate. Do. In Patent Document 2, a planar antenna formed on a substrate plane is used to detect the presence of a target in the front direction, and an antenna pattern formed on an end of the substrate plane in the vicinity of the substrate side surface is used to Detect the presence of a target. In Patent Document 3, a planar antenna formed on a substrate plane is used to detect the presence of a target in the front direction, and a dipole antenna formed on an end of the substrate plane near the side surface of the substrate is used to Detect the presence of a target. Patent Document 4 discloses a structure in which a horn antenna is disposed on the side surface of the substrate to enable a monopulse angle measurement method in the horizontal direction. FIG. 1 is a view for explaining the configuration of a wide angle azimuth detection system described in Patent Document 4.

  The wide-angle azimuth detection system S of FIG. 1 is composed of a dielectric substrate 1 and a metal member 2. In the dielectric substrate 1, the waveguides 11, 12 and 13 (see FIG. 3) are formed in a direction parallel to the substrate plane inside the substrate, and the openings of the waveguides 11, 12 and 13 at the side of the substrate The substrate planar antenna 14 is formed on the substrate plane (see FIG. 3). The metal member 2 is formed with the horn structures 21, 22, 23, and the openings (see FIG. 3) of the waveguides 11, 12, 13 and the connection parts of the horn structures 21, 22, 23 are respectively connected Is connected to the dielectric substrate 1.

  The horn structures 21 and 22 are for reception, and the horn structure 23 is for transmission. The board planar antenna 14 arranges the one for reception and the one for transmission with a high degree of freedom according to various monitoring methods. In the following description, a direction parallel to the thickness direction of the dielectric substrate 1 is defined as “horizontal direction”, and a direction perpendicular to the thickness direction of the dielectric substrate 1 is defined as “vertical direction”. Further, the surface on which the planar substrate antenna 14 is disposed is referred to as “front”, and the surface on which the horn structures 21, 22, 23 are formed is referred to as “side surface”.

Japanese Patent Application Publication No. 2007-049691 Patent No. 5464152 Patent No. 5609772 Unexamined-Japanese-Patent No. 2017-059907

  However, a waveguide is often used to propagate an electromagnetic wave to an arbitrary position in a transmitter or a receiver. However, Patent Document 4 describes that the horn is disposed in a waveguide formed in a direction parallel to the plane of the substrate (direction toward the side), but the waveguide formed on the surface facing in the front direction There is no mention of placing the horn structure on. Therefore, the present invention provides a horn antenna and a horn antenna array capable of directing the antenna directivity beam in a direction deviated from the front direction so as to detect the presence and the orientation of a target in the direction deviated from the front direction. The purpose is

  In order to achieve the above object, in the horn antenna according to the present invention, the horn having a structure in which the central axis of the horn is not perpendicular to the plane of the opening of the horn is connected in a shifted manner to the waveguide. The horn antenna according to the present invention has a first structure in which the horn is disposed at the tip of the waveguide and a second structure in which the horn is disposed on the narrow wall surface of the waveguide.

The first structure will be described. A horn antenna according to the present invention is a horn connection port having a rectangular connection port connected to a connection end of a rectangular waveguide, and a rectangular opening having an area larger than the area of the connection port for transmitting and receiving electromagnetic waves,
The point of intersection of the central axis of the rectangular waveguide with the plane of the opening and the center of the opening are offset, and the position of the perpendicular leg from the center of the connection port to the plane of the opening is the point of intersection It has a horn structure on a line connecting the centers of the openings.

Subsequently, the second structure will be described. A horn antenna according to the present invention includes a rectangular connection port connected to a window formed in a narrow wall surface of a rectangular waveguide, and a rectangular antenna having a larger area than the area of the connection port and transmitting and receiving electromagnetic waves. And
When viewed from a direction perpendicular to the plane of the opening, the center of the opening and the center of the connection port are offset, and the central axis of the rectangular waveguide is the center of the opening and the center of the connection port. And a horn structure in which the rectangular waveguides are connected so as to be perpendicular to a straight line connecting the two and so as to be opposite to the center of the opening with respect to the center of the connection port.

  In any of the structures, the central axis of the horn is not perpendicular to the plane of the horn opening, and the connection with the waveguide is also shifted, so that the beam direction can be inclined. The beam direction can be adjusted with the horn shape and the connected waveguide. Therefore, by arranging two horn antennas on the front of the substrate and adjusting the beam direction to adopt the monopulse angle measuring method, the presence and the orientation of the target can be detected at a wide angle. That is, the present invention can provide a horn antenna capable of directing the antenna directivity beam in a direction deviated from the front direction so as to detect the presence and the orientation of a target which is deviated from the front direction.

The specific horn structure is as follows.
The horn structure is characterized in that the center of the connection port is on a center line of one of two opposing sides of the opening when viewed in a direction perpendicular to the plane of the opening.
The horn structure is so shifted that one side of the connection port is in contact with one side of the opening or far from the center of the opening with respect to the center of the opening when viewed in a direction perpendicular to the plane of the opening. It is characterized by
The waveguide is characterized in that a step is formed on a narrow wall surface facing the window.
The horn structure is characterized in that a horn surface connecting the opening and the connection port has a step shape.

  The horn structure is characterized in that the opening and the connection port are separated by 0.8 times or more of the wavelength of the electromagnetic wave. In order to adjust the beam direction to a desired direction, the distance between the opening and the connection port (the length of the horn) needs to be 0.8 times or more of the wavelength of the electromagnetic wave.

  The horn antenna array according to the present invention is characterized in that the plurality of horn antennas are arranged in parallel such that all straight lines connecting the center of the connection port and the center of the opening are parallel. The directivity of an electromagnetic wave can be controlled by using the beam forming method in the present horn antenna array.

  The above inventions can be combined as much as possible.

  The present invention provides a horn antenna and a horn antenna array capable of directing the antenna directivity beam in a direction deviated from the front direction so as to detect the presence and orientation of a target which is deviated from the front direction. it can.

It is a figure showing composition of a wide angle direction detection system relevant to the present invention. It is a figure which shows the principle of the monopulse angle-measurement system of this indication. It is a figure explaining the structure of the wide angle direction detection system relevant to the present invention. It is a figure explaining the structure of the horn antenna concerning the present invention. It is a figure explaining the structure of the horn antenna concerning the present invention. It is a figure explaining the structure of the horn antenna concerning the present invention. It is a figure explaining the structure of the horn antenna concerning the present invention. It is a figure explaining the structure of the horn antenna concerning the present invention. It is a figure explaining the structure of the horn antenna concerning the present invention. It is a figure explaining the structure of the horn antenna concerning the present invention. It is a figure explaining the structure of the horn antenna concerning the present invention. It is a figure explaining the effect of the horn antenna concerning the present invention. It is a figure explaining the effect of the horn antenna concerning the present invention. It is a figure explaining the structure of the horn antenna array which concerns on this invention.

  Embodiments of the invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments. In the present specification and drawings, components having the same reference numerals denote the same components.

(Embodiment 1)
FIG. 4 is a diagram for explaining the horn antenna 101 of the present embodiment. The horn antenna 101 is a first structure in which the horn is disposed at the tip of the waveguide. 4C is an isometric view of the horn antenna 101. FIG. Moreover, the front view which looked at the side view seen from the direction of A of FIG.4 (C) from the direction of FIG. 4 (A) and B is shown in FIG.4 (B).

The horn antenna 101 is a horn antenna having a rectangular connection port 41 connected to the connection end of the rectangular waveguide 70 and a rectangular opening 42 having an area larger than the area of the connection port 41 for transmitting and receiving electromagnetic waves,
The position of the foot C2 of the vertical line from the center C1 of the connection port 41 to the plane of the opening 42, with the point of intersection A between the central axis 71 of the rectangular waveguide 70 and the plane of the opening 42 and the center B of the opening 42 shifted. Is on a line connecting the intersection point A and the center B of the opening.

  The waveguide 70 propagates the electromagnetic wave supplied from the left side of FIG. Further, the waveguide 70 propagates the electromagnetic wave received by the horn unit 40 to the left side of FIG. 4 (A). The horn portion 40 has a connection port 41 and an opening 42, and has a frustum structure having an upper bottom and a lower bottom. This frustum is not symmetrical, and the connection port 41 is shifted in the Y direction with respect to the opening 42 (see FIG. 6 (B)). Further, in the horn portion 40, the connection port 41 may be shifted in the X direction and the Y direction with respect to the opening 42 (see FIG. 6A).

  The horn portion 40 is connected to the end of the waveguide 70 at the connection port 41, but is connected with the center C1 of the connection port 41 and the central axis 71 of the waveguide 70 shifted. FIG. 4B is a view for explaining the shifted state of the horn portion 40 and the waveguide 70. “A” is an intersection point of the central axis 71 and the opening 42, and is the center position of the waveguide 70 on the plane of the opening 42. “B” is the center of the opening 42. “C2” is a perpendicular leg from the center C1 of the connection port 41 to the surface of the opening 42, and is the center position of the connection port 41 on the surface of the opening 42.

  The beam direction is inclined from the Z direction to the Y direction by connecting the horn unit 40 and the waveguide 70 as shown in FIG. 4 with the shape of the horn unit 40 as shown in FIG. And a straight line connecting the

Second Embodiment
FIG. 5 is a view for explaining the horn antenna 102 of the present embodiment. The horn antenna 102 is a second structure in which the horn is disposed on the narrow wall surface of the waveguide. 5C is an isometric view of the horn antenna 102. FIG. Moreover, the front view which looked at the side view seen from the direction of A of FIG.5 (C) from the direction of FIG.5 (A) and B is shown in FIG.5 (B).

The horn antenna 102 has a rectangular connection port 41 connected to the window 72 formed in the narrow wall surface of the rectangular waveguide 70, and a horn having a rectangular area 42 larger than the area of the connection port 41 for transmitting and receiving electromagnetic waves. An antenna,
When viewed in a direction perpendicular to the plane of the opening 42, the center B of the opening 42 and the center C1 of the connection port 41 are offset, and the central axis 71 of the rectangular waveguide 70 is the center B of the opening 42 and the connection port It has a horn structure in which the rectangular waveguide 70 is connected so as to be perpendicular to a straight line connecting with the center C1 of 41 and on the opposite side of the center B of the opening 42 with respect to the center C1 of the connection port 41 .

  The waveguide 70 propagates the electromagnetic wave supplied from the right side of FIG. Further, the waveguide 70 propagates the electromagnetic wave received by the horn unit 40 to the right side of FIG. 5 (B). The shape of the horn portion 40 is the same as the description of the horn antenna 101.

  The horn portion 40 is connected to the window 72 of the waveguide 70 at the connection port 41, but is connected with the center C1 of the connection port 41 and the central axis 71 of the waveguide 70 shifted when viewed from the Z direction Ru. FIG. 5B is a view for explaining a state where the horn portion 40 and the waveguide 70 are shifted. “B” is the center of the opening 42. “C2” is a perpendicular leg from the center C1 of the connection port 41 to the surface of the opening 42, and is the center position of the connection port 41 on the surface of the opening 42. The straight line connecting point B and point C2 on the surface of the opening 42 is perpendicular to the center line 71, and the center line 71 is connected to the point C2 on the opposite side of the center B of the opening 42.

  The beam direction is inclined from the Z direction to the Y direction by connecting the horn unit 40 and the waveguide 70 as shown in FIG. 5 with the shape of the horn unit 40 as shown in FIG. And a straight line connecting the

(Shape of horn)
7 and 8 are diagrams for explaining another shape of the horn portion 40. FIG. The horn structure is so offset that one side of the connection port 41 is in contact with one side of the opening 42 or far from the one side of the opening 42 with respect to the center B of the opening 42 when viewed in a direction perpendicular to the plane of the opening 42 It is characterized by FIG. 7 is a view for explaining the horn portion 40 having a shape in which one of the side surfaces of the frustum is parallel to the Z direction. FIG. 8 is a view for explaining the horn portion 40 having a shape in which one of the side surfaces of the frustum overhangs when viewed from the connection port 41. As shown in FIG. The horn unit 40 shaped as shown in FIG. 7 or 8 may be connected to the waveguide 70 to form a desired beam direction.

  FIG. 9 is a view for explaining another shape of the horn portion 40. As shown in FIG. FIG. 9C is an isometric view of the horn antenna 101. Moreover, the front view seen from the direction of FIG. 9 (A) and B from the side view seen from the direction of A of FIG.9 (C) is shown to FIG. 9 (B). The horn structure is characterized in that a horn surface connecting the opening 42 and the connection port 41 is stepped. FIGS. 4 to 8 illustrate the case where the shape of the horn portion 40 is a frustum. The shape of the horn portion 40 is not limited to the frustum. As for the shape of the horn portion 40, the horn surface may be formed in a step shape as shown in FIG. In FIG. 9, one of the horn surfaces is parallel to the Z direction, and the horn portion 40 having a shape having steps on the other three surfaces will be described. However, it is not necessary to form a level | step difference in all the horn surfaces other than the horn surface parallel to Z direction.

(Structure of waveguide)
FIG. 10 is a view for explaining the structure of the waveguide 70. As shown in FIG. 10B is an isometric view of the horn antenna 102. FIG. FIG. 10A is a view for explaining a cut surface obtained by cutting the horn antenna 102 in a plane parallel to the Z direction including the center line of the waveguide 70. FIG. In the case of the horn antenna 102, the waveguide 70 is characterized in that a step 73 is formed on a narrow wall surface facing the window 72. In the horn antenna 102, the propagation direction of the electromagnetic wave in the waveguide 70 and the beam direction formed in the opening 42 of the horn portion 40 are largely different. Therefore, by forming the step 73 at a position facing the window 72 of the waveguide 70, the return loss can be reduced.

Example 1
A horn antenna 101 as shown in FIG. 11 was produced, and it was verified how the beam direction changes depending on the amount of deviation Δ between the waveguide 70 and the horn section 40. FIG. 11A is an isometric view of the horn antenna 101. FIG. FIG. 11B is a view of the horn antenna 101 as viewed from the Y direction. The size of the opening 42 of the horn antenna 101 is 2.1 λ in the X direction and 1.5 λ in the Y direction. λ is the wavelength of the electromagnetic wave. Further, the height of the horn portion 40 (the distance between the opening 42 and the connection port 41) is 0.8λ.

  The verification results are shown in FIG. 12 and FIG. 12 and 13 illustrate the beam direction. FIGS. 12A and 13 show the inclination of the beam direction in the X direction when the Z direction is 0 degree. FIG. 12B shows the tilt of the beam direction in the Y direction when the Z direction is 0 degree. As shown in FIG. 12B, the beam direction has almost no inclination in the Y direction. On the other hand, as shown in FIG. 12A, it can be seen that the beam direction has an inclination of about 30 degrees in the X direction.

  FIG. 13 illustrates the change in beam direction with respect to the amount of deviation Δ. The beam direction is inclined approximately 25 degrees in the X direction when Δ = 0λ, approximately 30 degrees in the X direction when Δ = 0.1λ, and approximately 36 degrees in the X direction when Δ = 0.2λ. As described above, by adjusting the amount of deviation between the waveguide 70 and the horn portion 40, it is possible to form a beam in a desired direction. Similarly, the beam can be formed in a desired direction by adjusting the deviation between the center of the opening 42 of the horn 40 and the center of the connection port 41.

  From the above verification, the horn antenna according to the present invention can form a beam in a desired direction by adjusting the shape of the horn portion 40 and the amount of deviation between the waveguide 70 and the horn portion 40. Specifically, it is possible to incline 30 degrees in the azimuth direction while keeping the beam direction in the center in the elevation direction. By using two such horn antennas, it is possible to detect the presence and orientation of the target at a wide angle by adopting the monopulse angle measurement method described in FIG.

(Example 2)
In order to improve directivity, a plurality of horn antennas 101 or 102 may be arranged in parallel, and a beam forming method may be applied. FIG. 14 is a diagram for explaining the horn antenna array 201 of this embodiment. The horn antenna array 201 arranges the horn antennas 102 in parallel such that all straight lines connecting the center of the connection port 41 and the center of the opening 42 are parallel. That is, the horn antenna array 201 has a structure in which a plurality of horn antennas 102 are arranged in a line by aligning the beam directions. Although the horn antennas 102 are arranged in the present embodiment, the horn antennas 101 may be arranged.

(Other embodiments)
The structures of the above inventions can be combined as much as possible.

S: wide-angle azimuth detection system 1: dielectric substrate 2: metal members 11, 12, 13: waveguide 14: substrate planar antenna 21, 22, 23: horn structure 24: housing surface 25, 26: housing angle 27: diffraction Structures 31, 32, 33: radome members 31 ', 32', 33 ': film members 40: horns 41: connection ports 42: openings 70: waveguides 71: center lines 72: windows 73: steps

Claims (8)

A horn antenna having a rectangular connection port connected to a connection end of a rectangular waveguide, and a rectangular opening having an area larger than the area of the connection port for transmitting and receiving an electromagnetic wave,
The point of intersection of the central axis of the rectangular waveguide with the plane of the opening and the center of the opening are offset, and the position of the perpendicular leg from the center of the connection port to the plane of the opening is the point of intersection A horn antenna comprising a horn structure on a line segment connecting centers of openings. A horn antenna having a rectangular connection port connected to a window formed in a narrow wall surface of a rectangular waveguide, and a rectangular opening having an area larger than the area of the connection port for transmitting and receiving electromagnetic waves,
When viewed from a direction perpendicular to the plane of the opening, the center of the opening and the center of the connection port are offset, and the central axis of the rectangular waveguide is the center of the opening and the center of the connection port. A horn structure having the rectangular waveguide connected such that the rectangular waveguide is perpendicular to a straight line connecting the two and opposite to the center of the opening with respect to the center of the connection port . The horn structure is
The horn according to claim 1 or 2, wherein the center of the connection port is on the center line of one of two opposing sides of the opening when viewed in a direction perpendicular to the plane of the opening. antenna. The horn structure is
When viewed in a direction perpendicular to the surface of the opening, one side of the connection port is in contact with one side of the opening or deviated to be farther from the center of the opening than the one side of the opening. The horn antenna according to any one of claims 1 to 3.   5. The horn antenna according to claim 3, wherein a step is formed on a narrow wall surface of the waveguide facing the window.   The horn antenna according to any one of claims 1 to 5, wherein in the horn structure, a horn surface connecting the opening and the connection port has a step shape.   The horn antenna according to any one of claims 1 to 6, wherein in the horn structure, the opening and the connection port are separated by 0.8 times or more of the wavelength of the electromagnetic wave.   A horn antenna array in which a plurality of horn antennas according to any one of claims 1 to 7 are arranged in parallel such that all straight lines connecting the center of the connection port and the center of the opening are parallel.

Images