JPS62131605A - Plane antenna for microwave - Google Patents

Abstract

PURPOSE:To reduce the loss at a feeding part and to eliminate undesired radiation from the feeding part by feeding power to antenna patterns through a nearly sectorial cavity resonator and feeding power to the antenna patterns in phase. CONSTITUTION:An input radio wave fed from a probe 8b of an input connector 8a is propagated in a broadwise direction only of a cavity resonator 7 because the reflected waves from a guide wall 9a are made in phase in the probe 8b and the distance between the probe 8b and the guide wall 9a is selected as nearly lambdag/4. The input radio wave reaches plural conversion probes 10 along the sectorial cavity resonator 7 and fed to the antenna patterns 5 via a feeding point 6 by a conversion probe 10. Since the cavity resonator 7 is formed sectorial, the distance from the probe 8b of the input connector 8a to the plural conversion probes 10 is all equal. Thus, the power is supplied in phase to the antenna patterns 5 and the polarized faces of all the antenna patterns 5 is arranged. Moreover, since the distance between the conversion probes 10 and the guide wall 9b is selected nearly as lambdag/4, no effect of the reflected wave from the guide wall 9b is given.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a microwave planar antenna that utilizes traveling waves.

[Background technology]

A microwave planar antenna using a microstrip line utilizes the radiation energy from the microstrip line as antenna gain. Therefore, if the power feeding section to the antenna is also constituted by a microstrip line, the radiated energy from the power feeding section causes a loss in antenna gain and causes unnecessary radiation.

Furthermore, dielectric loss in the dielectric material constituting the substrate also results in antenna gain loss.

When the antenna aperture is small, these losses do not have much of an effect, but as the frontage area increases, the length of the feed system increases accordingly, and the above losses become a serious problem.

That is, as shown in FIG. 6, in a microwave planar antenna consisting of a feeding section 1, an antenna pattern row 2, and a termination section 3, the wider the frontage area, the longer the microstrip line of the feeding section 1 becomes. This results in an increase in losses.

[Purpose of the invention]

The present invention has been made to improve the above points, and its purpose is to provide a planar microwave antenna that reduces loss at the power feeding section and eliminates unnecessary radiation from the feeding section. It's about doing.

[Disclosure of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below as an example based on the drawings.

FIG. 1 is a top view of a microwave planar antenna showing an embodiment of the present invention, FIG. 2 is a back view of the same, FIG. 3 is a sectional view of the same, and FIGS. 4 and 5 are sectional views of the above. It is an enlarged view of the main part. An antenna pattern row 5 is formed on the front surface of the dielectric substrate 4 so that its feeding points 6 are arranged in an arc, and antenna patterns 14. A fan-shaped cavity resonator 7 is installed.

The circular arc portion 7a of the cavity resonator 7 is located at a position corresponding to the circular arc in which the feeding points 6 are arranged, and the input portion 8 is installed in the fan-shaped corner portion. The input section 8 constitutes a waveguide-coaxial conversion circuit, and is supplied with electric power through an input connector 8a. The distance between the probe 8b of the input connector λg 8a and the tube wall 98 is approximately λy/4 (
(Can it be a positive integer multiple of 〒?).

In addition, the feeding point 6 of the cavity resonator 7 and the antenna pattern array 5
is connected by a plurality of conversion probes IO. The distance between the conversion probe IO and the tube wall 9b is approximately λf/4 (\
Even if it is a positive integer multiple of b), it becomes A.

Note that 11 is solder and 12 is a ground conductor.

Next, the operation of the above embodiment will be described. The input radio wave supplied from the probe 8b of the input connector 8a has a distance of approximately λL between the probe 8b and the tube wall 9a! 4 and b, so the tube wall 9a
The reflected waves from the probe 8b become in phase at the probe 8b, and all input radio waves advance only in the direction of the expansion of the cavity resonator 7. The input radio waves reach a plurality of conversion probes 10 along the fan-shaped cavity resonator 7, and are supplied by the conversion probes 10 to the antenna pattern array 5 via the feeding point 6. Here, since the cavity resonator 7 is fan-shaped, the distances from the probe 8b of the input connector 8a to the plurality of conversion probes 10 are all equal. Therefore, since power is supplied to the antenna pattern arrays 5 in the same phase, the planes of polarization of all the antenna pattern arrays 5 are aligned. Furthermore, since the distance between the conversion probe io and the tube wall 9b is approximately λy/4, there is no influence of reflected waves from the tube wall 9b.

Therefore, in this embodiment, the power loss in the power supply section is different from that in the case where the power supply section is configured with micro strip 9 plines, and there is no dielectric loss (due to the substrate material) or radiation loss, and the power loss is caused by the tube wall 9a * 9b. *Conductor loss only occurs at the ground conductor hill.

Another embodiment according to the present invention is shown in FIG. In this example,
Radio wave absorbing materials are installed on the tube walls 9a and 9b of the above embodiment, and although the radio waves are slightly consumed by the radio wave absorbing material 13, the distance restriction of λf, A is removed, so the band can be further widened. can be achieved.

Further, there is an effect that unnecessary mode radio waves are less likely to be generated within the cavity resonator 7.

〔Effect of the invention〕

As described above, according to the present invention, in a microwave planar antenna using a microstrip line, power is supplied to the antenna pattern row by a substantially fan-shaped cavity resonator, and the antenna pattern row is fed with the same phase. Since it is possible to supply power at the
A microwave planar antenna without unnecessary radiation from the power feeding section could be provided.

[Brief explanation of drawings]

FIG. 1 is a top view of a microwave planar antenna showing an embodiment of the present invention, and FIG. 2 is a back view of the same. 4... Dielectric substrate, 5... Antenna pattern row, 6
... Feeding point, 7... Cavity resonator, 7a... Arc part, 8... Input section, IO... Conversion probe.

Claims (1)

[Claims] (1) In a microwave planar antenna using a microstrip line, a substantially fan-shaped spatial resonator with an input section at the latch is installed on the back side of the substrate on which the antenna pattern row is formed, and the antenna pattern row is , each feed point is formed at a position corresponding to the sector-shaped circular arc part, the feed point and the cavity resonator are connected by a conversion probe, and the power input from the input section is converted to the cavity resonance. 1. A planar antenna for microwaves, characterized in that the antenna is supplied to an antenna pattern array through a transducer and a conversion probe.