JPH05226922A - Microstrip antenna - Google Patents

Abstract

PURPOSE:To use the microstrip antenna for a linearly polarized wave also for the microstrip antenna for a circularly polarized wave. CONSTITUTION:A radiation electrode 11 and an electrode 15 insulated from a ground electrode 12 are formed on a side face of a dielectric board 10 to attain the reception of a circularly polarized wave through degeneration separation. The electrodes are formed on one side, two sides opposite to each other or two adjacent sides. A return loss characteristic is varied by the position of the electrode 15 and number of the electrodes 15. Furthermore, the resonance frequency is adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a microstrip antenna used in a navigation system or the like, and more particularly to a microstrip antenna capable of transmitting / receiving circularly polarized waves.

[0002]

2. Description of the Related Art In a GPS navigation system or the like, a small antenna for receiving a signal from a satellite is required, and use of a microstrip antenna is considered as one of them.

In this microstrip antenna, a radiation electrode having a size of a half of the wavelength of light received is provided on the surface of a dielectric substrate, and a ground electrode is formed on the entire back surface. There are square and circular radiating electrodes, and by devising their shape, the receiving frequency can be broadened.

Since signals such as GPS signals from satellites use circularly polarized waves, a structure is considered in which microstrip antennas can also receive such circularly polarized waves. In order to use the microstrip antenna for circular polarization, a structure provided with a degenerate separation element is considered.

FIG. 8 shows an example of a rectangular microstrip antenna having such a degenerate separation structure, in which a cutout portion is formed at a corner of a radiation electrode 81 provided on the surface of a rectangular dielectric substrate 80.
Formed 85. As a result, (a) of FIG.
The return loss characteristic shown in FIG. 7 has a band as shown in FIG. 7B, and circular polarization reception becomes possible. In addition, in the circular radiation electrode, the degenerate separation structure is obtained by the protrusion and the notch.

[0006]

When forming an electrode for circularly polarized waves as described above, pattern accuracy of the electrode is required. Particularly, when a substrate having a high dielectric constant is used, the dimensional accuracy of the electrodes has a great influence. When forming electrodes by printing, it is very difficult to obtain strict accuracy.

Moreover, it is difficult to obtain desired characteristics due to variations in the dielectric material of the substrate and variations in the electrode precision. In order to correct this and match it with a predetermined characteristic, it was necessary to remove part of the electrode pattern.

The present invention solves such a problem and provides a microstrip antenna capable of circularly polarized wave reception with a simple structure.

[0009]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems by arranging an electrode insulated from a radiation electrode and a ground electrode on the side surface of a dielectric substrate to enable degenerate separation. is there.

That is, in the microstrip antenna having the radiation electrode on the front surface of the dielectric substrate and the ground electrode on the entire back surface, the radiation electrode and the electrode insulated from the ground electrode are provided on the side surface of the dielectric substrate. It is characterized by

[0011]

The mode degeneration is separated by the electrode added to the side surface of the dielectric substrate, the return loss characteristic can be adjusted, and the circular polarized wave can be received.

It is also possible to adjust the return loss characteristics of the circularly polarized microstrip antenna, that is, to widen the band and lower the resonance frequency.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the present invention. A radiating electrode 11 is formed by printing and baking a copper thick film paste on the surface of a rectangular dielectric substrate 10 having a dielectric constant of about 20, and a gold electrode is formed on the back surface, and a similarly formed ground electrode 12 is formed on the back surface. It is a thing. Radiation electrodes on the side surface of the dielectric substrate 10.
11, a plurality of electrodes 15a, 15b insulated from the ground electrode 12,
15c is formed.

A Mg-Ca-Ti-based ceramic fired substrate having a dielectric constant of 21 was molded into a 25 mm square and a thickness of 6 mm, and a 20 mm square radiation electrode was formed on the surface. A 25 mm square ground electrode was formed on the entire back surface. As a result, a 1.6 GHz band single point back-feed microstrip antenna was formed.

A 5 × 5 mm copper foil insulated from the radiation electrode and the ground electrode was attached to the side surface of the dielectric substrate with a double-sided tape. The electrode 15a is placed at a position corresponding to the end of the radiation electrode 11,
The electrode 15b was attached to the position 15c at a position corresponding to the center of the radiation electrode 11.

In the microstrip antenna having the above structure, the return loss characteristic before forming the electrode 15 was only the peak of 1.6 GHz as shown in FIG. 7 (a). The return loss characteristics changed as shown in (a) of 2. In addition, when the electrode 15b is formed, as shown in FIG.
The return loss characteristics changed as shown in (b), and the bandwidth was about 20 MHz. When the electrode 15c was formed, the return loss characteristic was changed as shown in FIG.

As described above, degeneration is separated by adding electrodes, and a microstrip antenna for circular polarization, which is satisfactory in return loss characteristics, can be obtained. With such a structure, degenerate separation is possible even with a microstrip antenna having a square electrode, and a linearly polarized microstrip antenna can be used for circularly polarized waves.

In the GPS, the band is used only about 2 MHz, and even in the design of the return loss characteristic, a very small degenerate separation is sufficient. According to the invention, the size of the electrodes,
The degree of degeneracy separation can be controlled by the position or the like.

FIG. 3 is a perspective view showing an example in which electrodes are formed on two side surfaces. The electrodes 35 of the same size as those in the example shown in FIG. 1 are formed at opposite positions on opposite side surfaces of a rectangular dielectric substrate 30. The electrode 35a and the electrode 35d face each other, and the electrode 35c and the electrode 35f face each other.

FIG. 4 shows the return loss characteristics in the example shown in FIG. When only the electrodes 35a and 35d were formed, the return loss characteristics changed as shown in FIG. 4 (a) and the bandwidth was about 30 MHz. Furthermore, if electrodes 35c and 35f are added and there are four locations, the return loss characteristics will change as shown in Fig. 4 (b) and the bandwidth will also be about
It was as wide as 40MHz.

FIG. 5 is a perspective view showing another example in which electrodes are formed on two side surfaces. Electrodes of the same size as the example shown in FIG.
55 are formed at the opposite positions on the adjacent side surfaces of the dielectric substrate 50. The electrode 55a and the electrode 35c are formed on the same side surface at positions corresponding to the ends of the radiation electrode 51, and the electrode 55g is formed at the center of the adjacent side surface.

FIG. 6 shows the return loss characteristics in the example shown in FIG. Electrodes 35a, 35c and electrode 35
When g was formed, the return loss characteristics changed as shown in FIG. Also, in this case, the center frequency is from 1.6 GHz to 15 GHz.
It was changing to lower MHz. In this way, degenerate separation and frequency adjustment are possible depending on the position where the electrode is formed.

[0024]

According to the present invention, by degenerate separation, a microstrip antenna for linearly polarized waves can be used for circularly polarized waves, and the return loss characteristic can be adjusted by the position and number of electrodes formed. You can

Further, it is possible to match variations in the characteristics of the circularly polarized microstrip antenna with additional electrodes, and it is possible to easily obtain a microstrip antenna having desired characteristics. By forming electrodes in advance and trimming the electrodes according to the characteristics, desired return loss characteristics can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of the return loss characteristic.

FIG. 3 is a perspective view of another embodiment of the present invention.

FIG. 4 is an explanatory diagram of the return loss characteristic.

FIG. 5 is a perspective view of another embodiment of the present invention.

FIG. 6 is an explanatory diagram of the return loss characteristic.

FIG. 7 is an explanatory diagram of the return loss characteristic of the antenna.

FIG. 8 is a plan view of a conventional example.

[Explanation of symbols]

 10, 30, 50: Dielectric substrate 11, 31, 51: Radiation electrode 15, 35, 55: Electrode

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuyoshi Takano 828 Hinohara, Tamagawa, Hamahara, Hiki-gun, Saitama Prefecture Toko Co., Ltd. Tamagawa factory

Claims (3)

[Claims] 1. A microstrip antenna having a radiation electrode on the front surface of a dielectric substrate and a ground electrode on the entire back surface, wherein a side surface of the dielectric substrate is provided with an electrode insulated from the radiation electrode and the ground electrode. Microstrip antenna characterized by. 2. A microstrip antenna having a square dielectric substrate provided with a radiation electrode on the front surface and a ground electrode provided on the entire back surface, wherein two opposite side surfaces of the dielectric substrate are provided.
A microstrip antenna comprising an electrode insulated from a radiation electrode and a ground electrode. 3. A microstrip antenna in which a radiation electrode is provided on the front surface of a rectangular dielectric substrate and a ground electrode is provided on the entire back surface, and two adjacent side surfaces of the dielectric substrate are provided.
A microstrip antenna comprising an electrode insulated from a radiation electrode and a ground electrode.