JPH06244634A - Feeding circuit for planar antenna - Google Patents

Abstract

PURPOSE:To emit radio waves of different phases into a radial waveguide corresponding to the peripheral angle. CONSTITUTION:A cylindrical void 15 fixed to the central lower part of a radial waveguide conductive lower board 2, coaxial cable 3 for supplying radio waves to the void 15 and phase adjusting mechanism (short pin) 16 for peripherally rotating the excited radio waves at a prescribed position inside the void are fixed. The radio wave supplied into the void by the coaxial cable 3 is resonated on the resonance condition decided by the size of the cylindrical void 15, and the radio wave provided with the same peripheral angle phase as the radio wave resonated inside the void is excited inside the radial waveguide composed of a conductive upper board 1 and the lower board 2. Since the mechanism (short pin) 16 is arranged inside the cylindrical void 15 so as to generate the radio wave for which the phase is changed corresponding to the peripheral angle and a change at 360 deg. is provided by full circulation concerning the radio wave resonated inside the void, the radio wave to be supplied from the inside of the void to the radial waveguide is fully circulated and changes the phase at 360 deg..

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plane antenna suitable for use in satellite broadcasting reception, and more particularly to a feed circuit for a plane antenna using a radial waveguide such as a radial line slot antenna.

[0002]

2. Description of the Related Art A monolayer planar antenna using a radial waveguide is described in Japanese Patent Application No. Hei 2-174603. A front view of this one-layer structure is shown in FIG.
Fig. 1 (a) is a cross-sectional view taken along the line AA in Fig. 1 (a), and Fig. 1 (b) shows the positional relationship of the phase adjusting dielectric provided in the radial waveguide of Fig. 1 ( It is shown in c). The phase adjusting dielectric 13 is hatched. In Figure 3,
As the phase adjusting dielectric, the end face shape in contact with the upper plate 1 is shown.

In this antenna, a circular conductive plate (radiating plate) 1 and a circular conductive lower plate 2 are separated by a predetermined distance.
To form a radial waveguide for axisymmetric mode propagation, connect the coaxial cable 3 to the center of the lower plate 2, supply the transmission radio wave from the coaxial cable 3 to the radial waveguide, and use the matching reflector 4 to guide the radial waveguide. Propagates radially outward in the waveguide. This radio wave first enters the phase adjusting dielectric 13, is almost non-reflecting, and exits with the in-tube phase φ depending on the circumferential angle θ.

Next, in the process of propagating outward, circularly polarized waves are gradually radiated toward the front of the antenna by the radiation slot pair 5. The radio waves not radiated by the total radiating slot pair 5 are directed to the annular slot 9 by the reflector 14 and radiated to the front of the antenna. The radio wave has already passed through the phase adjustment dielectric 13, and the radio wave satisfies the phase condition of circular polarization on a concentric circle centered on the center of the antenna.
Therefore, the radio wave radiated from the annular slot 9 is completely the same polarization as the circular polarization by the radiation slot pair 5.

[0005]

In the example of FIG. 1, the phase adjusting dielectric 13 is required, but a high dielectric constant is desirable in order to reduce the size of the dielectric. In this case, the spiral shape makes it difficult to process. Therefore, the present invention presents a power supply circuit that does not use a spiral-shaped phase adjusting dielectric and that emits a radio wave in which the phase varies in the circumferential direction in the radial waveguide and changes by 360 ° over the entire circumference. The purpose is to do.

[0006]

A planar antenna feeding circuit according to the present invention includes a radial waveguide, a resonator provided in the center of the waveguide, a feeding pin for exciting the resonator, and an exciting element. It consists of a phase adjustment mechanism in the circumferential direction of the radio wave, and emits a radio wave that changes in phase by 360 degrees in the entire circumference and changes in phase depending on the circumferential angle. In the example of FIG. 1, the dielectric is formed in a spiral shape to eliminate reflection, whereas in the present invention, a resonator is provided to utilize reflection to make the radio wave emitted into the radial waveguide a desired one. Is characterized by.

[0007]

[Function] The resonator is connected to the radial waveguide at the central portion of the radial waveguide by the above-mentioned resonator, the feed pin arranged in the resonator, and the phase adjusting mechanism, and the radio wave emitted from the resonator has a circumferential angle. The phase is different due to, and the change is 360 ° over the entire circumference. Therefore, all slot pairs are placed on concentric circles in order to radiate circularly polarized waves of the same phase. In addition, the phase adjustment mechanism allows the phase change in the circumferential direction to be arbitrary.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A planar antenna feeding circuit according to an embodiment of the present invention will be described below with reference to the drawings. (First embodiment)

The feed circuit for a planar antenna according to this embodiment includes a radial waveguide and a cylindrical cavity as a resonator provided in a conductive lower plate of the waveguide, and a feed pin arranged therein and a phase adjustment. This is a power feeding circuit that emits radio waves whose phase changes from the cavity depending on the angle in the circumferential direction and changes 360 ° over the entire circumference.

FIG. 2 (a) is a front view of a plane antenna provided with a feed circuit for a plane antenna according to this embodiment,
The positional relationship of the cylindrical cavity as a resonator is shown.
5 is hatched. A sectional view taken along the line BB of FIG. 2 (a) is shown in FIG. 2 (b).

This power supply circuit comprises a cylindrical cavity 15 fixed to the lower central part of the radial waveguide conductive lower plate 2, a coaxial cable 3 for supplying radio waves to the cavity, and an exciting radio wave circulated at a predetermined position in the cavity. Mechanism to rotate in the direction (short pin)
16 is fixed.

The radio wave supplied to the inside of the cavity by the coaxial cable 3 resonates under the resonance condition determined by the size of the cylindrical cavity 15, and inside the radial waveguide constituted by the conductive upper plate 1 and the lower plate 2. In addition, a radio wave with the same angular phase in the circumferential direction as the radio wave resonating in the cavity is excited.

In the cylindrical cavity 15, a mechanism (short pin) 16 for generating a radio wave that has a phase that changes depending on the circumferential angle of the radio wave that resonates in the cavity and that changes 360 degrees over the entire circumference.
, The radio wave supplied to the radial waveguide from the inside of the cavity has a 360 ° phase change all around,
It is suitable for generating a desired polarized wave from a plurality of slots formed in concentric circles and arranged as disclosed in Japanese Patent Application No. 2-174603.

It should be noted that one or more short pins 16 may be arranged as a mechanism for obtaining a 360 ° phase change all around the cavity.

[0015]

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG.

FIG. 3 (a) is a front view of a plane antenna provided with a feed circuit for a plane antenna according to this embodiment,
The positional relationship of the cylindrical cavity as a resonator is shown.
5 is hatched. A sectional view taken along the line CC of FIG. 3 (a) is shown in FIG. 3 (b). This example
This is an example in which a dielectric plate 17 is used as the mechanism for rotating the excitation radio wave in the circumferential direction of the first embodiment, and the position of the cylindrical cavity provided in the radial waveguide conductive lower plate of FIG. 3 (a). The relationship is shown in Fig. 3 (c).

In this embodiment, as shown in FIG. 3 (b), a dielectric plate 17 is arranged in place of the short pin 16 as a mechanism for rotating the excitation radio wave in the cylindrical cavity 15 in the circumferential direction. The dielectric plate 17 can give a desired circumferential phase change to the electric wave excited in the drive by the coaxial cable 3, and is suitable as a feed circuit for a planar antenna.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIG.

FIG. 4 (a) is a front view of a plane antenna provided with the feed circuit for the plane antenna according to this embodiment,
The positional relationship of the circular dielectric as a resonator is shown. A sectional view taken along the line DD of FIG. 4 (a) is shown in FIG. 4 (b). In this embodiment, the circular dielectric 18 is used as the resonator of the first embodiment, and the circular dielectric is hatched.

In this embodiment, as shown in FIG. 4 (a), a part of the circular dielectric is cut out (not shown) as a phase adjusting mechanism for rotating the excitation radio wave in the circumferential direction in the circular dielectric 18 as a resonator. (Perturbation element) 19 is arranged. Since the dielectric 18 as a resonator has a circular shape, it is suitable as a feed circuit for a planar antenna.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIG.

FIG. 5 (a) shows a power feeding circuit for a planar antenna according to this embodiment, which is disclosed in Japanese Patent Application No. Hei 2-158974.
4 is a front view of an example applied to a two-layer radial line slot antenna described in No. E in FIG. 5 (a)
A sectional view taken along the line E is shown in Fig. 5 (b). In this embodiment, it is possible to provide a radial line slot antenna that can share both right-handed and left-handed polarized waves.

In this embodiment, as shown in FIG. 5 (b), a slot plate 20 having a large number of slots, a frame 21 facing the slot plate, and a slot plate disposed between the slot plates. The upper layer waveguide and the lower layer waveguide are formed by the separated partition plate 22 and the partition plate 22 and the frame 21.
A circular shape as the resonator of the present invention for feeding the upper waveguide to the center between the slot plate 20 and the partition plate 22 through the inner cavity of the cylindrical conductor 23 mounted in the center between Coaxial cable 24 for feeding the dielectric 18
And a coaxial cable 25 for feeding the lower waveguide is provided in the resonator formed by the cylindrical conductor 23 and the cylindrical cavity 15 attached to the frame.

Circular dielectric resonator 1 for feeding the upper waveguide
8 is provided with a notch 19 as a phase adjustment mechanism, and as a phase adjustment mechanism of a resonator formed by a cylindrical conductor 23 feeding the lower waveguide and a cylindrical cavity 15 attached to a frame, Is provided with a protrusion (perturbation element) 26. Since this embodiment does not use the coaxial double-structured line described in Japanese Patent Application No. Hei 2-158974, it is suitable as a feeding circuit for a two-layer radial line slot antenna.

[0025]

As is apparent from the above description, according to the present invention, it is possible to provide a power feeding circuit having a simple structure suitable for a planar antenna without using a spiral-shaped dielectric having a high dielectric constant. ．

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a single-layer structure planar antenna disclosed in Japanese Patent Application No. 2-174603.

FIG. 2 is a diagram showing a power supply circuit according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a power supply circuit according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a power supply circuit according to a third embodiment of the present invention.

FIG. 5 is a diagram showing a power supply circuit according to a fourth embodiment of the present invention.

[Explanation of symbols]

1 ... Conductive upper plate, 2 ... Conductive lower plate, 3 ... Coaxial cable,
4 ... Matching reflector, 5 ... Radiating slot, 6 ... Reflecting material, 9 ...
Annular termination slot, 10 ... Conductive annular plate, 13 ... Phase adjusting spiral dielectric, 14 ... Reference line, 15 ... Cylindrical cavity, 16 ... Circumferential phase adjusting mechanism (short pin), 1
7 ... Circumferential phase adjusting mechanism (dielectric plate), 18 ... Circular dielectric, 19 ... Circumferential phase adjusting mechanism (notch), 20 ... Slot plate, 21 ... Frame, 22 ... Partition plate, 23 ... Cylindrical dielectric Body, 24 ... Coaxial cable for upper layer waveguide, 25 ... Coaxial cable for feeding lower layer waveguide, 26 ... Circumferential phase adjusting mechanism (protrusion).

Claims (1)

[Claims] 1. A radial waveguide, a resonator installed in the center of the waveguide, a power feeding pin for exciting the waveguide through the resonator, and a phase adjusting mechanism in the circumferential direction of the excited radio wave. Feeder circuit for a planar antenna characterized by having.