JPS59207703A - Microstrip antenna - Google Patents

Abstract

PURPOSE:To obtain a microstrip antenna excellent in weather resistant property by interposing the third dielectric plate a specified thickness between a radial conductor element and a passive element and arranging the first and the second dielectric plates thinner than wavelength at the outside. CONSTITUTION:A radial conductor element 1 and a passive element 2 of nearly same shape [radius (a), (b)] are formed opposite to a face of the first and the second dielectric plates 4, 4' which are thinner compared with wavelength. The third dielectric plate 5 of specified length (h) is interposed between the elements 1 and 2. The dielectric plate 5 is bonded to the dielectric plates 4, 4' with an adhesive. The face of the dielectric plate 4' on which the element 2 is not formed faces to outside. Accordingly, the elements 1 and 2 are kept at a specified distance (h) by the dielectric plate 5 and shut off from outside air by dielectric plates 4, 4'. As the elements 1 and 2 are not exposed directly to air or moisture by such a structure, they are hardly oxidized and do not generate exfoliation etc., the weather resistant property is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an unbalanced planar circuit resonant type microstriped knob antenna, and particularly to a structure for improving weather resistance.

Microstrip antennas, which can be manufactured by etching a copper laminate, have a simple structure and can be mass-produced, but the usable frequency band is narrow. Therefore, as shown in Figure 1, 1
A parasitic device consisting of a first dielectric plate 4 on which a radiation conductor element 1 is formed by etching or the like on the front surface and a ground conductor plate 3 formed on the back surface, and a conductor plate having approximately the same shape as the radiation conductor element 1 on one side. A planar resonant type micro in which a second dielectric plate 4' formed at a position facing the radiation conductor element 1 is held at a predetermined interval so that the cable 2 is held at a predetermined interval to achieve a wide band. Strip antennas are also known.

- The first and second dielectric plates 4, 4' are dielectric plates thinner than the wavelength, and the radius a of the radiation conductor element 1 and the radius of the parasitic element 2 are is equal to V. Note that micropower is supplied to the radiation conductor element 1 from a center conductor of a coaxial cable (not shown).

The conventional microstrip antenna mentioned above.

It is vulnerable to ultraviolet rays, wind and rain, temperature changes, etc., and has the disadvantage that antenna characteristics deteriorate when the metal part oxidizes or peels off from the dielectric. Therefore, it is necessary to protect the antenna using a radome or the like. If a radome or the like is used, the planar structure, which is a feature of the microstrip line, will be lost and the line will become three-dimensional, requiring a larger installation space. It's a trench, radiating conductor element 1 and parasitic element 2
In order to keep the first and second dielectric plates at a predetermined distance, it is necessary to fix the first and second dielectric plates with metal screws, etc., which has a negative effect on the electrical characteristics and has many disadvantages such as making the antenna heavier. There is.

An object of the present invention is to solve the above-mentioned conventional drawbacks and provide a microstrip antenna with excellent weather resistance. Another object of the present invention is to.

The object of the present invention is to provide a lightweight microstrip antenna with a simple configuration.

In the microstrip antenna of the present invention, a ground conductor plate is formed on the back surface of a first dielectric plate that is thinner than the wavelength, a radiating conductor element is formed on the front surface, and the radiating conductor element is placed at a predetermined distance from the radiating conductor element. In an unbalanced planar circuit resonant microstrip antenna in which a parasitic element made of a conductive plate of approximately the same shape is arranged, the glossy parasitic element is formed on one surface of a second dielectric plate that is thinner than the wavelength, A third dielectric plate having a predetermined thickness is interposed between the parasitic element and the radiation conductor element.

Of course, it is possible to arrange a plurality of each of the radiation conductor elements and parasitic cables. -Furthermore, manufacturing is easy if the radiation conductor elements and the like are formed by etching. Furthermore, it is desirable that the third dielectric plate has a low dielectric constant, and is made of urethane foam.

If a honeycomb or the like is used, the dielectric constant is close to 1, and the structure can be made lightweight.

Next, the present invention will be explained in detail with reference to one drawing.

FIG. 2(a) is a perspective view showing an embodiment of the present invention,
Figure (b) is a sectional view thereof. That is, radiating conductor elements 1. of radiating conductor elements having approximately the same shape (radii α, b). Parasitic elements 2 are formed at positions facing each other on one side of first and second dielectric plates 4.4' which are thinner than the wavelength. A ground conductor plate 3 is formed on the back surface of the first dielectric plate 4. These can be easily formed by etching @ tension laminates. Then, a third dielectric plate 5 having a predetermined thickness of 5 is interposed between the radiation conductor element 1 and the parasitic element 2. Dielectric plate 5, first and second dielectric plates 4°4'
and are glued together. The twenty-fifth dielectric plate 4' has the surface on which the parasitic element 2 is not formed facing outward. Therefore, the radiation conductor element 1 and the parasitic element 2 are held at a predetermined distance by the dielectric 5, and are shielded from the outside air by the first and second dielectric plates 4, 4'. According to the above structure, since the radiation conductor element 1 and the parasitic element 2 are often directly exposed to air and moisture, they are difficult to oxidize, and since peeling does not occur, the weather resistance is improved. Further, since no metal screws or the like are required to maintain the predetermined spacing, deterioration of bacterial properties can be prevented. It goes without saying that the third dielectric plate 5 is desirably made of a material with a low dielectric constant (relative dielectric constant close to 1) such as urethane foam. In this case, it is lightweight and has excellent electrical properties.

FIG. 3 is a diagram showing the reflected power-frequency characteristics of a micro-rostrip antenna in which the third dielectric plate 5 is made of polyurethane foam and a conventional antenna of the same shape. A solid curve A shows the characteristics of an embodiment in which the dielectric plate 5 is made of foamed urethane, and a one-dot curve curve B6 shows the characteristics of a craft antenna having the same shape. From the same figure.

It is understood that there is almost no shadow @ caused by the urethane foam. We also conducted a test on the radiation directional characteristics, but no change was observed. Even when a dielectric material with a high permittivity is used, excellent characteristics can be achieved by appropriately designing the dimensions and shape of the radiation conductor element, etc.

FIG. 4 is a perspective view showing another embodiment of the present invention, in which several rice grains are arranged in a position 1a where a radiation conductor element 1 and an insatiable force element 2 face each other. The radiation conductor elements 1 of the number of rice grains are connected by a power supply distribution circuit 6. Other points are the same as above, and the same reference numerals indicate the same components. In this case as well, it goes without saying that the weather resistance is good as described above.As described above, in the present invention, in d5, a third dielectric plate of a predetermined thickness is interposed between the radiation conductor element and the parasitic element. Since the first and second dielectric plates, which are thinner than the wavelength, are arranged on the outside, a wide band can be achieved with a simple structure, and an antenna with excellent weather resistance can be provided. Of course, it is also possible to form a plurality of radiation conductor elements in an array. There is no need for metal screws or the like to maintain a predetermined distance between the radiation conductor element and the parasitic element. Further I
'l) If the third dielectric plate (1) is made of foamed polyurethane or the like, the amount of c will be extremely high, and the influence on the electrical characteristics will hardly be a problem, which is extremely convenient.

[Brief explanation of the drawing]

FIGS. 1(a) and (b) are an oblique elliptical diagram and a sectional view showing an example of a conventional microstrip antenna with a wide band, and FIGS. 2(a) and (b) are an embodiment of the present invention. FIG. 3 is a diagram showing an example of reflected power-frequency characteristics of the above embodiment, and FIG. 4 is a perspective view showing another embodiment of the present invention. In the figure, 1...radiation conductor element 2...parasitic element 3...ground conductor plate 4...first dielectric plate 4'...second dielectric plate 5...th Dielectric plate 6 of 3...Power distribution circuit. 2151 Picture Den 20 (a) City)

Claims (1)

[Claims] (1) A grounded conductor plate is formed on the back surface of the first dielectric plate, which is thinner than the wavelength, and a radiating conductor element is formed on the front surface, and the radiating conductor element is placed at a predetermined distance from the radiating conductor element. In an unbalanced planar circuit resonant microstrip antenna in which a parasitic element made of a conductor plate having approximately the same shape as is arranged, the parasitic element is formed on one surface of a second dielectric plate that is thinner than the wavelength, A third layer having a predetermined thickness is provided between the parasitic element and the radiation conductor element.
A microstrip antenna characterized by interposing a dielectric plate. (2. Micros according to claim 1) IJ
In the tube antenna, a plurality of the radiation conductor elements are formed on the first dielectric plate, the plurality of radiation conductor elements are connected by a feeding distribution circuit, and the parasitic element is connected to the second dielectric plate. A plurality of radiation conductor elements are formed on a plate to face the plurality of radiation conductor elements. (3) In the microstrip antenna according to claim 1 or 2, the radiation conductor element and the parasitic element are formed by etching a conductor plate formed on a dielectric plate. Features. (4) In the microstrip antenna according to claim 1, 2, or 3, the third dielectric plate is made of a dielectric material with a low electric yield rate such as urethane foam. Features.