JPS6266704A - Metallic bar loaded micro strip antenna - Google Patents

Abstract

PURPOSE:To obtain an array antenna where the voltage standing wave ratio is high and the required area is small, by arranging plural metallic bars, which are connected electrically to either of an earth conductor and a center conductor, between the earth conductor and the center conductor. CONSTITUTION:An earth conductor 1 is arranged in parallel with a discoid center conductor 3 with a dielectric 2 between them and is connected to the center conductor of a coaxial line omitted in the figure by a linear conductor 4 whose one end is connected to the center conductor 3. Plural metallic bars 5 each of which has one end face connected to the earth conductor 1 are arranged in the dielectric 2. The dielectric whose specific inductive capacity is about one is used, and metallic bars 5 are loaded for a desired use frequency, thereby making it possible to transmit and receive wave with the center conductor whose diameter is reduced by about 20%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of a microstrip antenna having a disk-shaped center conductor.

INDUSTRIAL APPLICATION This invention is utilized for the component antenna of the array antenna used in the frequency band above ultra-high frequency, or the feeding element of the antenna with a reflective mirror.

〔overview〕

The present invention provides a microstrip antenna consisting of a flat ground conductor and a disc-shaped center conductor that are arranged parallel to each other. By arranging multiple metal rods that are connected to each other, the voltage standing wave ratio is widened when used as a QL body, and the required area is small when used as an element. It is possible.

[Prior Art] As a conventional antenna of this kind, for example, 1 (
Comparative Patent No. 3,921.177 (1975 IL
L1] Day 8) As shown in "Structure and array of microstrip antenna", it is composed of a ground conductor 1, a dielectric 2, and a center conductor plate 3', and the length l of one side of the center conductor plate 3' is equal to the length l of the dielectric 2. Assuming that the relative dielectric constant is ε and the wavelength used is λ, it was necessary to do the following.

In addition, FIG. 9 shows a vertical cross-sectional view of another conventional microstrip antenna. In this figure, the center conductor 3 is disk-shaped, and the feed line 4 is located below the ground conductor 1. It is connected to the center conductor 3 through a small hole. In this case, the diameter of the center conductor 3 had to be approximately the same as l in FIG.

On the other hand, when you want to generate multi-beams with a reflector-equipped antenna that uses multiple microstrip antennas as feeding elements by adding a reflector and set the distance between each beam to an arbitrary value, feed the feed according to the size of the beam spacing. It is also necessary to make the element spacing large or small.

[Problem that the invention seeks to solve]

However, as shown in the above equation, for microstrip antennas used as feeding elements, the dimension β is suppressed depending on the wavelength used, and conversely, increasing the relative permittivity ε of the dielectric reduces radiation efficiency, so the beam spacing must be reduced. There was a drawback that it could not be narrowed down below a certain value.

The present invention solves this drawback and can miniaturize the array antenna by using it as an element antenna of an array antenna, and can also configure a multi-beam antenna with arbitrary beam spacing by using an antenna with a reflector as an element antenna. The purpose is to provide a metal rod loaded microstrip antenna.

[Means for solving problems]

The metal rod-loaded microstrip antenna according to the present invention has a ground conductor, a disk-shaped center conductor, a metal rod, and a coaxial type power feeding section, and the metal rod creates an electrostatic charge between the ground conductor and the disk-shaped center conductor. It is characterized in that it has means for loading a capacity.

That is, the present invention provides a microstrip antenna in which a flat ground conductor and a disc-shaped center conductor are arranged parallel to each other, and the center conductor is connected to a feed line. A plurality of metal rods are arranged in the gap, and each of the plurality of metal rods is electrically connected to either the ground conductor or the center conductor.

[Effect]

If the wavelength used in a microstrip antenna is constant, the dimensions of the center conductor are inversely proportional to the square root of the relative permittivity of the dielectric between the center conductor and the ground conductor. Increasing the antenna's radiation efficiency decreases. Therefore, by placing a metal rod in the gap between the center conductor and the ground conductor to apply an electrostatic charge, the center conductor can be made smaller.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a first embodiment of the present invention, and FIG. 2 is a top view thereof.

In both figures, a ground conductor 1 is arranged parallel to a disc-shaped center conductor 3 via a dielectric 2, and a linear conductor 4 whose one end is connected to the center conductor 3 is connected to the center conductor of a coaxial line (not shown). Connected.

The feature of the present invention lies in that a plurality of metal rods 5, one end surface of which is connected to the ground conductor 1, are arranged in the dielectric body 2.

The figure shows, as an example, a case where four metal rods 5 are arranged.

In FIG. 1, in the case where a dielectric whose dielectric constant is approximately l is used and there is no metal rod 5, the diameter of the disk-shaped center conductor 3 is 10 cm, and the distance between the ground conductor 1 and the center conductor 3 is 7m
According to experiments, the optimum radiable frequency when m is 1
, 57G) Iz.

Next, the diameter of the center conductor 3 is set to 8 cm, and the four metal rods 5 are
It has been experimentally confirmed that when the center conductor 3 and the nearby metal rod 5 are placed at a spacing of about 1/16λ, the optimum frequency for radiation is 1.60 GHz because capacitance is loaded between the center conductor 3 and the metal rod 5 near it. Ta.

That is, by loading the metal rod 5 for the desired frequency to be used, it becomes possible to transmit and receive data using a center conductor with a diameter that is approximately 20% smaller.

Furthermore, it has been similarly confirmed through experiments that the bandwidth of the voltage standing wave ratio is approximately 20% wider.

FIG. 3 is a vertical sectional view of the second embodiment of the present invention, and the fourth embodiment
The figure is a top view thereof. The difference from the embodiment shown in FIG. 1 is that one end of the metal rod 5 is connected to the center conductor 3;
By loading capacitance as shown in the figure, the diameter of the center conductor can be reduced and a wider band can be achieved.

FIG. 5 is a vertical sectional view of the third embodiment of the present invention, and the sixth embodiment
The figure is a top view thereof. In Figure 5, the conductor rod 6 supporting the center conductor 3 in Figure 1 is connected to the ground conductor 1 along the central axis of the center conductor 3, and this position corresponds to the node of the high-frequency electric field, so it is electrically has almost no negative effect. FIG. 7 is a top view of another embodiment of the circularly polarized antenna in which the metal rods 5 are arranged at 90° intervals.
Other types of circularly polarized antennas can also be constructed depending on the positional relationship of the linear conductor 4 and the linear conductor 4.

Furthermore, in the first embodiment shown in FIG. 1 and the second embodiment shown in FIG. 3, the plurality of metal bars are electrically connected to either the ground conductor or the center conductor. It is also possible to connect a part of the metal rod to the ground conductor and the remaining metal rod to the center conductor. However, in this case, the metal rods connected to different conductors must have a sufficient gap from each other.

The present invention is not limited to the above embodiments,
For example, it is clear that the present invention can also be applied to a microstrip antenna in which a notch is partially provided on the outer periphery of a disk-shaped center conductor.

〔Effect of the invention〕

As explained above, in the metal rod-loaded microstrip antenna of the present invention, the diameter of the disk-shaped center conductor can be reduced compared to conventional ones by providing the metal rod. It becomes possible to arrange a large number of center conductors closer to each other than in the conventional case.

Therefore, in a multi-beam antenna in which a plurality of feed elements of the present invention are combined with a reflecting mirror, the beam spacing between each beam can be narrower than in the conventional antenna. Further, since a plurality of disk-shaped center conductors can be arranged on one fixed ground conductor in a larger number than in the conventional antenna without using a reflecting mirror, an array antenna can be constructed that is smaller than the conventional antenna and has the same performance.

Furthermore, on the other hand, since the voltage standing wave ratio can be made wider, it is possible to actually use a single microstrip antenna, which has conventionally been unused due to its narrow band.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a first embodiment of the present invention. FIG. 2 is a top view of the above embodiment. FIG. 3 is a longitudinal sectional view of a second embodiment of the present invention. FIG. 4 is a top view of the above embodiment. FIG. 5 is a longitudinal sectional view of a third embodiment of the present invention. FIG. 6 is a top view of the second embodiment. FIG. 7 is a top view of another embodiment of the invention. FIG. 8 is a perspective view of a conventional example. FIG. 9 is a longitudinal sectional view of another conventional example. DESCRIPTION OF SYMBOLS 1... Ground conductor, 2... Dielectric material, 3... Disk-shaped center conductor, 3'... Rectangular center conductor, 4... Linear conductor, 5... Metal rod, 6... A linear conductor connecting the ground conductor and the center conductor.

Claims (1)

[Claims] (1) In a microstrip antenna in which a flat ground conductor and a disc-shaped center conductor are arranged in equilibrium, and this center conductor is connected to a feeder line, the gap between the ground conductor and the center conductor is 1. A metal rod-loaded microstrip antenna, characterized in that a plurality of metal rods are arranged, and each of the plurality of metal rods is electrically connected to either the ground conductor or the center conductor.