JPH11214923A - Array antenna device - Google Patents

Abstract

(57) [Problem] To provide an array antenna device fed by a radial waveguide, there is a problem that reflection characteristics of feeding are poor. SOLUTION: A microstrip line for phase adjustment is formed between a radiation conductor and an excitation probe.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an array antenna device used for communication, radar and the like, and more particularly to a planar array antenna device for feeding power by a radial waveguide for exciting linearly polarized waves.

[0002]

2. Description of the Related Art FIG. 2 is a block diagram of a conventional array antenna device for feeding power by a radial waveguide, which is disclosed in, for example, the 1993 IEICE Autumn National Convention Lecture Book B-65. ) Is a top view, FIG. 2B is FIG.
It is AA sectional drawing of. In the figure, 1 is a dielectric substrate, 2
Is a radiating conductor formed on the dielectric substrate 1, 3 is a pair of two circular conductor plates facing each other in parallel at an interval, and a conductor plate having a curvature along the outer periphery is used for two circular conductor plates. Is a radial waveguide formed by closing the radial waveguide.
Reference numeral 4 denotes an excitation probe which is connected to the radiation conductor 2, penetrates through the dielectric substrate 1, projects into the radial waveguide 3, and excites the radiation conductor 2, and 5 denotes a radial probe 3 which projects from the outside into the radial waveguide 3. Power supply probe. Reference numeral 6 denotes a virtual concentric circle centered on the center point of the dielectric substrate 1 on which the excitation probe 5 is disposed, and the connection position of the radiation conductor 2 to the excitation probe 5 is reversed on the adjacent virtual concentric circle 6. Is set. The difference between the radii of adjacent virtual concentric circles 6 is set to a half wavelength in terms of the propagation wavelength in the radial waveguide 3 at the used frequency, and the circumferential arrangement intervals of the excitation probes 5 on each virtual concentric circle are equal. Set to the interval. The feed probe 4 is arranged at the center of the radial waveguide 3.

Next, the operation will be described. An RF signal input to the power supply probe 4 from the outside propagates inside the radial waveguide 3 from the center of the radial waveguide 3 to the outside. The RF signal excites the radiation conductor 2 via the excitation probe 5. Since the RF signal has the same amplitude and phase at points equidistant from the center, the radiating conductors 2 arranged on the same virtual concentric circle 6 are excited with the same amplitude and the same phase. Further, since each virtual concentric circle 6 has an interval of a half wavelength at the propagation wavelength in the radial waveguide 3, and since the directions of the radiation conductors 2 on the adjacent virtual concentric circles 6 are opposite, all of the radiation The excitation phases of the conductors 2 become equal. As a result, a radiation pattern of linearly polarized light having directivity in a direction perpendicular to the surface on which the radiation conductor 2 of the dielectric substrate 1 is arranged is obtained. Further, the excitation amplitude of each radiation conductor 2 can be adjusted by changing the length and radius of the excitation probe 5 to change the amount of coupling of the RF signal propagating in the radial waveguide 3 to the excitation probe 5.

[0004]

In an array antenna apparatus for feeding power by a radial waveguide, when an RF signal propagated from a feed probe into the radial waveguide excites each excitation probe, the RF signal captured by the excitation probe is reduced. Most go to the radiating conductor, but some are reflected and re-emitted into the radial waveguide without going to the radiating conductor. In the conventional array antenna device which supplies power with a radial waveguide for linearly polarized excitation, in order to excite each radiation conductor at the same phase, an excitation probe is provided in the radial waveguide with a radius from the center of the radial waveguide at the operating frequency. They are arranged concentrically and spread at an interval of half the propagation wavelength in the waveguide. Therefore, on the contrary, the RF signal reflected and re-emitted from each excitation probe propagates through the radial waveguide and is incident on the feeding probe at the center of the radial waveguide at the same phase, thereby deteriorating the reflection characteristics of the antenna. There was a problem. The present invention has been made to solve the above problems, and has as its object to improve the reflection characteristics of an array antenna fed by a radial waveguide.

[0005]

An array antenna apparatus according to the present invention does not connect an excitation probe directly to a radiation conductor, but via a microstrip line for phase adjustment formed on a dielectric substrate together with the radiation conductor. Some are connected.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a configuration diagram of an array antenna device showing an embodiment of the present invention,
FIG. 1A is a top view, and FIG.
It is sectional drawing. In the figure, 1, 2, 3, 4, 5, and 6 are the same as those in FIG. 7 is formed on the dielectric substrate 1,
One is a phase adjustment microstrip line connected to the radiation conductor 2 and the other is connected to the excitation probe 4.
The power supply probes 4 are not all arranged on the virtual concentric circle 6 but are arranged with a variation.

Next, the operation of the array antenna device configured as described above will be described. An RF signal input to the power supply probe 4 from the outside propagates inside the radial waveguide 3 from the center of the radial waveguide 3 to the outside. The RF signal is captured by the excitation probe 5 and excites the radiation conductor 2 via the microstrip line 7 for phase adjustment. The excitation probe 5 is not bound on the virtual concentric circle 6,
Since they are arranged with variations, the RF signal re-emitted from the excitation probe 5 by reflection does not enter the feeding probe 4 of the radial waveguide 3 at the same phase.
On the other hand, the phase difference caused by the uneven arrangement of the excitation probes 5 is adjusted by the microstrip line 7 for phase adjustment, and all the radiation conductors 2 are excited with the same phase. The amplitude difference is adjusted by the length and radius of the excitation probe 5. As a result, the reflection characteristic can be improved while obtaining the same linearly polarized radiation pattern as in the conventional example.

[0008]

According to the present invention, a configuration in which an excitation probe is directly connected to a radiation conductor in a conventional array antenna apparatus for feeding power by a radial waveguide is provided by a microstrip line for phase adjustment between the excitation probe and the radiation conductor. In this configuration, the excitation phases of the radiating conductors can be made equal in phase while making the arrangement of the excitation probe uneven, and the same radiation pattern as that of the conventional array antenna device is formed, and the reflection characteristics are obtained. Can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of an array antenna device according to the present invention.

FIG. 2 is a configuration diagram showing a conventional array antenna device.

[Explanation of symbols]

1 dielectric substrate, 2 radiation conductor, 3 radial waveguide,
4 feeding probe, 5 excitation probe, 6 virtual concentric circle, 7 microstrip line for phase adjustment.

Claims (1)

[Claims] 1. A radial waveguide comprising two circular conductor plates facing each other in parallel at an interval, and closing the two circular conductor plates by a conductor plate having a curvature along an outer periphery. A circular dielectric substrate attached to one surface of the radial waveguide, a plurality of radiation conductors formed on the dielectric substrate, and a microstrip line for phase adjustment connected to the radiation conductor. Power is supplied to an excitation probe connected to the microstrip line for phase adjustment, penetrating the dielectric substrate, and protruding into the radial waveguide, and a radial waveguide attached to the center of the radial waveguide. An array antenna device composed of a power supply probe and a power supply probe.