JPH0878948A - Leakage wave waveguide cross slot array antenna - Google Patents

Abstract

PURPOSE: To provide the leakage wave waveguide cross slot array antenna with which both the radio wave of anticlockwise circular polarization wave and the radio wave of clockwise circular polarization wave can be alternatively received with simplified/low-priced configuration. CONSTITUTION: This leakage wave waveguide cross slot array antenna is constituted by almost parallelly arranging plural radial waveguides 1A, 1B, 1C... formed with plural cross slots arranged in the direction of a tube axis on the upper surface. Each cross slot is composed of a pair of a left side cross slot 4 and a right side cross slot 4' whose centers are arranged on both sides of a center line, respectively, formed by linking the centers of the lateral width of the upper surfaces of respective radial waveguides in the direction of the tube axis. By moving shield conductor boards 5 in their respective arranging directions along the upper surfaces of respective radial waveguides 1A, 1B, 1C..., only one of the left side cross slot 4 and the right side cross slot 4' is selectively shielded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leaky wave waveguide cross-slot array antenna used as a satellite broadcasting receiving antenna for mounting on a mobile body, and particularly to a right side under a simple and inexpensive structure. The present invention relates to a leaky wave waveguide cross slot array antenna capable of selectively receiving a circularly polarized wave and a left polarized wave.

[0002]

[Prior Art] IEICE Technical Report V0L.93
No. 40 A ・ P 93-25 announced "In-vehicle satellite broadcasting reception 1-layer leaky wave waveguide slot array antenna" is a satellite broadcasting reception with tilt angle mounted on a moving body such as a vehicle or ship. It is intended for use as an antenna for use, and uses cross slots as slots.

As shown in the perspective view of FIG. 7, this leaky wave waveguide cross-slot array antenna includes a plurality of radiation waveguides 21A to 21L arranged adjacently in parallel and each radiation waveguide. A power supply waveguide 22 for synthesizing received radio waves,
The power supply probe 23 supplies the received radio waves synthesized by the power supply waveguide 22 to a converter (not shown). Each of the radiation waveguides 21A to 21L is composed of a leaky wave waveguide in which a plurality of cross slots 24 are arranged on the upper surface along the tube axis direction and a circular polarization matching slot pair 29 is formed at the end. ing. The coupling between each radiation waveguide and the feeding waveguide is performed through a π branch 28 including a coupling window 27 and an inductive post 26. The circular polarization matching slot pair 29 can be omitted.

[0004]

The satellite radio waves currently used in Japan are right-hand circularly polarized waves only. However,
The DBS service started in June this year in the US uses both left-handed circular polarization and right-handed circular polarization, and each channel frequency band has right-handed circular polarization and left-handed circular polarization. Things are partially overlapped.

In the conventional satellite broadcasting receiver using the parabolic antenna, in order to cope with the above-mentioned receiving system using both polarized waves, the left and right circularly polarized received radio waves received by the parabolic antenna are respectively received. A method of converting to an intermediate frequency with one of two converters dedicated to polarization or installing an electrically controllable polarizer between an antenna and a single converter is considered. Following this satellite broadcasting receiver method using a parabolic antenna for a cross-slot array antenna, the cross-slot array antenna is configured to receive both left-handed circular polarization and right-handed circular polarization. , Convert each received radio wave of each polarization into an intermediate frequency with one of two converters dedicated to each polarization, or install an electrically controllable polarizer between the antenna and a single converter. It is necessary to do it.

However, the configuration in which two converters dedicated to each polarization are installed or an electrically controllable converter is installed has a problem of increasing the manufacturing cost of the entire receiving apparatus. Therefore, an object of the present invention is to provide a leaky-waveguide cross-slot array antenna capable of selectively receiving both left-handed circular polarization and right-handed circular polarization under a simple and inexpensive structure. , Eliminating the need for complicated and expensive polarization filters.

[0007]

A leaky wave waveguide cross-slot array antenna according to the present invention comprises a cross-slot and a cross-slot formed on both sides of the center of the upper surface of each radiation waveguide along the tube axis direction. And a shield conductor configured to selectively shield only one of the left cross slot and the right cross slot forming each cross slot by being moved in parallel to the upper surface of each radiation waveguide. It is equipped with a board.

[0008]

As shown in the partial plan view of FIG. 5, the pair of cross slots formed on the upper surface of each radiation waveguide is located on the left side from the center line C along the tube axis direction on the upper surface of each radiation waveguide. It is composed of a left cross slot 4 formed around a position separated by an offset amount d and a right cross slot 4 ′ formed around a position separated by an offset amount d to the right of the center line C. Cross slot 4 on each side
And 4'are two slots # 1 and # 2 intersecting at an angle φ.
It consists of The interval between two adjacent cross slots along the tube axis direction is L. If the incident direction of the radio wave is upward as shown by the arrow, right-hand circular polarization is selectively received by the left cross slot 4 and left-hand circular polarization is received by the right cross slot 4 '. Are selectively received.

The relationship between the above-mentioned arrangement of cross slots and the turning direction of the received circular polarized wave will be described with reference to FIG.
First, assume that a circularly polarized wave is emitted instead of receiving the circularly polarized wave. FIG. 6A shows how the distribution of the magnetic field component in the radiation waveguide changes with time. When the reciprocal of the frequency f of the radio wave is the period T, the time t shown on the leftmost side
The state of the distribution of the magnetic field component shifts to the right one by one with the passage of time T / 4 from the state of = 0, and the left cross slot 4 formed on the left side of the center line C and the center line C The positional relationship with the right cross slot 4'formed on the right side changes as shown in the figure. The magnetic field in the radiation waveguide is efficiently radiated in a state of being parallel to the longitudinal direction of each slot forming the cross slots 4, 4'on each side.

As a result, as shown in FIG. 6 (B), at time t = 0, one of the left cross slots 4 radiates a radio wave containing the magnetic field component H ₁₀ and, at the same time, the right cross slot 4 ′. Radio waves containing the magnetic field component H ₂₀ are radiated from one of the slots. At time t = (1/4) T, a radio wave including the magnetic field component H ₁₁ is radiated from the other slot of the cross slot 4 and at the same time, a radio wave including the magnetic field component H ₂₁ is emitted from the other slot of the right cross slot 4 ′. Is emitted.
At time t = (1/2) T, a radio wave including the magnetic field component H ₁₂ is radiated from one slot of the left cross slot 4 and the magnetic field component H ₂₂ is emitted from the other slot of the right cross slot 4 ′.
Radio waves including are emitted. At time t = (3/4) T, the radio wave including the magnetic field component H ₁₃ is radiated from the other slot of the left cross slot 4 and the radio wave including the magnetic field component H ₂₃ is radiated from the other slot of the right cross slot 4 ′. To be done. Therefore, paying attention to the directions of the magnetic field components H ₁₀ , H ₁₁ , H ₁₂ , and H ₁₃ , the radio waves radiated from the left cross slot 4 are right-handed circularly polarized waves. In addition, the magnetic field components H ₂₀ , H ₂₁ ,
Focusing on the directions of H ₂₂ and H _23, the radio waves radiated from the right cross slot 4 ′ have left-handed circularly polarized waves in opposite directions.

As shown in FIG. 5, by forming a pair of the left cross slot 4 and the right cross slot 4'on the upper surface of each radiation waveguide, radio waves of both right-handed and left-handed polarized waves can be radiated. become. Due to the reciprocity of radiation and reception, right-hand circular polarization is received by the left cross slot 4 and left circular polarization is received by the right cross slot 4 ′ based on the same principle as the above-mentioned radiation. Left cross slot 4
And the right cross slot 4 ′ are allowed to receive radio waves by only one of them by a shield conductor plate which selectively moves only one of the right cross slot 4 ′ and the right cross slot by being moved in parallel to the upper surface of each radiation waveguide. . Hereinafter, the present invention will be described in more detail with reference to Examples.

[0012]

1 is a partially exploded perspective view showing the structure of a leaky wave waveguide cross slot array antenna according to an embodiment of the present invention. This leaky wave waveguide cross-slot array antenna is a power feeding device that synthesizes a plurality of radiation waveguides 1A, 1B, 1C, ... The waveguide 2 and the power supply probe 3 that supplies the received radio waves synthesized by the power supply waveguide 2 to a converter (not shown) are provided. The coupling between each radiation waveguide and the feeding waveguide 2 is performed through the π branch 8 including the coupling window 7 and the inductive post 6 as in the case of the conventional example of FIG. 7.

Each of the radiation waveguides 1A, 1B, 1C, ... Is composed of a leaky wave waveguide in which a pair of a left cross slot 4 and a right cross slot 4'is arranged on the upper surface along the tube axis direction. ing. A metallic shield conductor plate 5 for selectively shielding only one of the left cross slot 4 and the right cross slot 4'is slidably held on the upper surface of each radiation waveguide. That is, in a state where the flexible elastic shield conductor plate 5 is bent in the tube axis direction of the radiation waveguide, both ends thereof are attached to both ends of the radiation waveguides 1A, 1B, 1C. By fitting into the fitting grooves 9a and 10a formed in the bodies 9 and 10, respectively, the radiation waveguides are held slidably in the arrangement direction. The shield conductor plate 5 has a slit 5a having a width half the width of the upper surface of each radiation waveguide.
Are formed at the same pitch as the arrangement pitch of the radiation waveguides.

FIG. 2 is a partial plan view (A) showing a state in which the right cross slot 4'is shielded by the shield conductor plate 5 and its BB 'sectional view. FIG. 3 is a partial plan view (A) showing a state in which the left cross slot 4 is shielded by the shield conductor plate 5 and its BB ′ sectional view. In this way, by shifting the shield conductor plate 5 in the arrangement direction by half the arrangement pitch of the radiation waveguides, the cross slot on one side can be completely shielded electrically. Although not shown in FIG. 1, the sliding of the shield conductor plate 5 can be easily realized by a combination of a restoring mechanism with a spring and a winding mechanism, an appropriate linear movement mechanism, or the like.

FIG. 4 is a partial plan view showing a part of another embodiment of the present invention. When the left cross slot 4 and the right cross slot 4'are arranged at the same position in the tube axis direction, they may overlap each other due to a decrease in the offset amount, an increase in the slot length forming each cross slot, and the like. In the present embodiment, the left cross slot 4 and the right cross slot 4'are arranged so as to be displaced from each other in the tube axis direction, thereby avoiding the overlapping of the two. In this embodiment, when a shield conductor plate having a slit having a width half the width of the upper surface of the radiation waveguide is used, the tip of the selected cross slot is partially shielded or a shield symmetrical cross slot is used. The tip may be partially exposed. However, this does not affect the majority of electrical properties.

The structure in which the left cross slot and the right cross slot are formed around the center line C while maintaining symmetry has been described above. However, if the frequencies are different between left-handed and right-handed circularly polarized radio waves, set different values so that the left and right cross-slot shapes and arrangements are optimal for the respective frequencies used. do it.

[0017]

As described in detail above, in the leaky-waveguide cross-slot array antenna of the present invention, each cross-slot is formed on both sides of the center of the upper surface of each radiating waveguide along the tube axis direction. It consists of a pair of left cross slot and right cross slot, and because it has a configuration in which only one cross slot is selectively shielded by a shield conductor plate, it is possible to use both left and right polarized waves under an extremely simple and inexpensive configuration. The effect of being able to selectively receive the radio wave of is produced.

As described above, the fact that the left-handed and right-handed circularly polarized waves can be selectively received with an extremely simple and inexpensive structure means that a conventional leaky-wave waveguide cross-slot array for a parabolic antenna or the like is used. It also greatly contributes to enhancing the superiority of the antenna.

[Brief description of drawings]

FIG. 1 is a partially exploded perspective view showing a configuration of a leaky wave waveguide cross slot array antenna according to an embodiment of the present invention.

FIG. 2 is a partial plan view (A) showing a usage state of the leaky wave waveguide cross-slot array antenna of FIG. 1 and a BB ′ cross-sectional view (B) thereof.

FIG. 3 is a partial plan view (A) showing a usage state of the leaky wave waveguide cross-slot array antenna of FIG. 1 and a BB ′ cross-sectional view (B) thereof.

FIG. 4 is a partial plan view showing a part of a leaky wave waveguide cross slot array antenna according to another embodiment of the present invention.

FIG. 5 is a conceptual diagram for explaining the operation of the present invention.

FIG. 6 is a conceptual diagram for explaining the operation of the present invention.

FIG. 7 is a perspective view showing a configuration of a conventional leaky wave waveguide cross slot array antenna.

[Explanation of symbols]

 1A, 1B, 1C ・ ・ ・ Radiation waveguide 2 Feed waveguide 3 Feed post 4 Left cross slot 4'Right cross slot 5 Shield conductor plate 5a Slit 6 Induction post 7 Coupling window 8 π branch 9,10 Holder 9a, 10a Shielding conductor plate mating groove

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiro Uematsu 2-3-6 Otemachi, Chiyoda-ku, Tokyo Within Nippon Steel Corporation (72) Inventor Takashi Ojima 2--6, Otemachi, Chiyoda-ku, Tokyo No. 3 Inside Nippon Steel Co., Ltd. (72) Inventor Naohisa Goto 6-15-1 A514 Dobashi, Misaki-ku, Kawasaki-shi, Kanagawa

Claims (6)

[Claims] 1. A leaky-waveguide cross-slot array antenna having a structure in which a plurality of radiation waveguides, each having a plurality of cross slots arranged in the tube axis direction, are arranged substantially parallel to each other. The slot is composed of a pair of a left cross slot and a right cross slot whose centers are arranged on both sides of a center line connecting the center of the lateral width of the upper surface of each radiation waveguide in the tube axial direction, and each of the radiation A shield conductor plate that selectively shields only one of the left cross slot and the right cross slot forming each cross slot by being moved along the upper surface of the waveguide and in the arrangement direction of each radiation waveguide. A leaky wave waveguide cross-slot array antenna characterized by being provided. 2. The pair of left cross slots and right cross slots forming each of the cross slots according to claim 1, wherein the pair of left cross slots and right cross slots are formed at the same position in the tube axis direction of each of the radiation waveguides. Leaky wave waveguide cross slot array antenna. 3. The leaky wave waveguide cross slot according to claim 1, wherein the left cross slot and the right cross slot are formed so as to have symmetry around the center line. Array antenna. 4. The pair of left cross slots and right cross slots forming each of the cross slots according to claim 1, wherein the pair of left cross slots and right cross slots are formed at positions displaced in the tube axis direction of each of the radiation waveguides. Leaky Waveguide Cross Slot Array Antenna. 5. The leaky-waveguide cross-slot array antenna according to claim 1, further comprising a drive mechanism for moving the shield conductor plate in the arrangement direction of the radiation waveguides. 6. The drive mechanism according to claim 5, wherein the drive mechanism includes a spring mechanism that returns the shield conductor plate to an initial position, and an electric motor that moves the shield conductor plate from the initial position against the spring mechanism. A leaky wave waveguide cross-slot array antenna characterized in that