JPS61163707A - Microstrip line antenna - Google Patents

Abstract

PURPOSE:To prevent a dielectric from being deteriorated by a time aging, by forming an electric insulating covered layer consisting of a material for absorbing ultraviolet rays, so as to face the outside surface of the dielectric on which a conductor is placed. CONSTITUTION:An antenna 1 is constituted by forming a crank-shaped strip conductor 3 on one surface of an electric insulating synthetic resin thin film 2, and thereafter, sticking a plate-shaped dielectric 4 so as to face the surface on which the strip conductor 3 of the synthetic resin thin film 2 has been formed, and forming a laminated body by sticking a metallic ground conductor 5 onto the surface of the side opposite to one surface of the dielectric 4 on which the strip conductor 3 has been placed. Subsequently, a solvent soluble fluorine compound paint of an ultraviolet ray absorbing type is painted by about 50g/m<2> onto a polyester film being the synthetic resin thin film 2. After the fluorine compound paint has been painted in this way, a coated film is formed by the fluorine compound paint, after drying the antenna 1 at 60 deg.C about 4-5hr. In this way, the coated film absorbs ultraviolet rays and ultraviolet rays are not absorbed by the dielectric 4. Accordingly, the dielectric 4 can be prevented from being deteriorated by a time aging, and a drop of the gain of the antenna 1 caused by a dielectric loss can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to microstripline antennas.

BACKGROUND ART An antenna is used to radiate a signal from a transmitter into space and to capture radio waves propagated in this space into a receiver. Various types of antennas have been developed to efficiently radiate and absorb radio waves. Frequency is 3~30G
In the so-called extremely high frequency band (SHF) of Hz, propagation loss is large, so a high gain antenna is required. For this reason, in recent years, microstrip line antennas have been developed as antennas for SHF. This microstrip line antenna is used in satellite communications and the like.

Low dielectric materials such as tetrafluoroethylene and polyethylene are used as dielectric materials for microstrip line antennas, but polyethylene is more widely used due to cost considerations.

However, polyethylene has problems with weather resistance. Since microstrip line antennas are used outdoors, the polyethylene deteriorates due to ultraviolet rays, and when polyethylene was used as the dielectric material, there was a problem in terms of service life.

OBJECTIVES It is therefore an object of the present invention to provide a microstrip line antenna which solves the above-mentioned technical problems and has improved weather resistance and significantly improved reliability and service life.

Embodiment FIG. 1 is a perspective view showing the basic structure of a microstrip line antenna, and FIG. 2 is a sectional view thereof.

The microstrip line antenna 1 is constructed by forming a crank-shaped strip conductor 3 on one surface of an electrically insulating synthetic resin thin film 2, and then facing the surface of the synthetic resin thin film 2 on which the strip conductor 3 is formed. Then, a flat dielectric material 4 is glued to the dielectric material 4 on which the strip conductor 3 is arranged.
A metal ground conductor 5 is adhered to the surface opposite to one surface to form a multilayer body, thereby configuring the microstrip antenna 1.

As the dielectric material 4, polyethylene is widely used as described above. Dielectric t* t, dielectric loss tangent ta of polyethylene
It is desired that dielectric properties such as nδ do not change over time.

However, polyethylene has poor weather resistance and is known to significantly increase the dielectric loss tangent tanJ due to deterioration due to ultraviolet rays.As the dielectric loss tangent tanδ increases, the dielectric loss increases, and the Problems arise such as no gain being obtained.

Therefore, in view of the above-mentioned problems, the inventors of the present invention designed the microstrip line antenna 1 to have the configuration described below, so that when polyethylene is used for the dielectric 4, the dielectric 4 does not change over time. The present inventors have discovered that a sufficient gain of the microstrip line antenna 1 can be obtained without deterioration due to the above, and have completed the present invention.

The present invention is a microstrip line antenna 1 characterized in that an electrically insulating coating layer made of a material that absorbs ultraviolet rays is formed facing the outer surface of a dielectric 4 on which a strip conductor 3 is arranged. In a preferred embodiment of the present invention, on the synthetic resin thin film 2,
Another preferred embodiment of the microstrip line antenna 1 is a microstrip line antenna 1 formed by coating an ultraviolet absorbing solvent-soluble fluororesin and using this synthetic resin thin film 2 as a coating layer, when the synthetic resin thin film 2 is formed, This is a microstrip line antenna 1 formed by adding a metal pigment such as titanium oxide (TiO2) that absorbs ultraviolet rays and using a thin PL/1.2 synthetic resin obtained as a laminated layer.

Yet another preferred embodiment includes a synthetic resin thin film 2;
This is a microstrip line antenna formed by adding a metal pigment that absorbs ultraviolet rays between a flat dielectric material 4, applying a resin and curing it to form an electrically insulating coating layer. According to the invention, an electrically insulating coating layer made of a material that absorbs ultraviolet rays is formed facing the outer surface of the dielectric 4 on which the strip conductor 3 is disposed, so that ultraviolet rays cannot reach the dielectric 4. This prevents deterioration of the dielectric 4 due to changes over time. Therefore, compared to the conventional configuration, the reliability of the Micros IJ tube line antenna 1 is improved, and the service life can be extended about 10 times.

The present invention will be described in detail below based on Examples 1 to 5.

Example 1 As the synthetic resin thin film 2, a commercially available polyester film (thickness: 50-100 μS) was used. Aluminum foil (20 layers thick) was adhered to the entire surface of this synthetic resin thin film 2 by dry lamination. This aluminum foil is for forming the strip conductor 3.

The remaining portions of the aluminum foil are removed by etching, leaving only the portion where the strip conductor 3 is to be formed.

In this way, the strip conductor 3 is placed on the synthetic resin thin film 2.
After forming the strip conductor 3, a commercially available polyethylene sheet (thickness: 1% m) is dielectrically connected via an adhesive polyethylene film (manufactured by Mitsui Petrochemicals Co., Ltd., trade name: AdmerNEO505) facing the surface on which the strip conductor 3 is formed. It was used as body 4 and heated and pressed. An aluminum plate (thickness l mm) as a ground conductor 5 is bonded to the surface of the dielectric 4 of the laminate in which the synthetic resin thin film 2 and the dielectric 4 are laminated in this way via the adhesive polyethylene film. The configuration is shown in the right side of Figure 1 and Figure 's2.

A UV-absorbing solvent-soluble fluorine-based paint (
Product name Lumiflon LF302) manufactured by Asahi Glass Co., Ltd. 5
Approximately 0.017 m of paint was applied.

After applying the fluorine-based paint in this manner, the microstrip line antenna 1 was dried at 60'C for about 4 to 5 hours to form a coating film using the fluorine-based paint.

In the microstrip line antenna 1 in which a fluorine-based paint is applied on the synthetic resin thin film 2 to form a coating film, when polyethylene is used as the dielectric material 4, the coating film absorbs ultraviolet rays. The dielectric 4 does not absorb ultraviolet light. Therefore, deterioration of the dielectric 4 due to changes over time can be prevented, and a decrease in the gain of the microstrip line antenna 1 due to dielectric loss can be prevented.

The microstrip line antenna on which the coating film was formed and the microstrip line antenna 1 on which the coating film was not formed were left outdoors, and changes in gain over time were measured. As a result, although the antenna without the coating showed a gain reduction of 1 to 2 dB and 8 degrees after 6 months, the microstrip line antenna with the coating
However, no decrease in profits was observed even after one year.

In this way, the microstrip line antenna 1
This makes it possible to improve weather resistance, reliability, and lifespan.

Example 2 A nylon film (thickness: 190 mm) was used as the synthetic resin thin film 2.
A microstrip line antenna 1 was constructed in the same manner as in Example 1 using the microstrip line antenna (μm). As a result, the same effects as in Example 1 were obtained.

Example 3 Adding 0 titanium oxide (Tiαh white) to polyester resin
．． 5% by weight was added to form a thin film of 50 to 100 μm using an inflation molding method to obtain a synthetic resin thin film 2.
And so. Aluminum foil was adhered to this synthetic resin thin film 2 by the dry lamination method as in Example 4.

This aluminum foil is made into the strip conductor 3 by etching as described above. After the strip conductor 3 is formed on the synthetic resin thin film 2 in this way, a polyethylene sheet as a dielectric material 4 is attached to one surface of the synthetic resin thin film 2 on which the strip conductor 3 is formed. At the same time as adhering via a polyethylene film, an aluminum substrate (thickness lnfi) as a ground conductor 5 is heated and pressed on the surface of the dielectric 4 opposite to the outer surface on which the strip conductor 3 is arranged. Therefore, the structure shown in the imperial edict in Figure 1 and in Figure 2 will be adopted.

A microstrip line antenna with such a configuration
Since titanium oxide (Ti02) is added to the synthetic resin thin film 2, the synthetic resin thin film 2 absorbs ultraviolet rays and prevents the ultraviolet rays from reaching the polyethylene sheet serving as the dielectric 4. Therefore, it is possible to prevent deterioration of the dielectric 4 due to changes over time. When a microstrip line antenna l having such a configuration was installed outdoors and changes in gain were measured, no decrease in gain was observed even after one year had passed. Further, the electrical properties (dielectric constant ε, dielectric loss tangent tan δ) of polyethylene as the dielectric material 4 were measured. The results are shown in Table 1.

Table 1 Table 1 also includes titanium oxide (Ties) as a comparative example.
) The dielectric properties of the microstrip line antenna l without the addition of

As understood from Table 1, the microstrip line antenna 1 according to the present invention shows no deterioration in dielectric properties such as dielectric constant ε and dielectric loss tangent tan δ. In this way, it is possible to prevent deterioration of the dielectric properties of the dielectric material 4 due to changes over time, and to improve the reliability and life of the microstrip line antenna l.

Example 4 Instead of titanium oxide (TiOz) in the synthetic resin thin film 2,
A microstrip line antenna 1 was manufactured in the same manner as in Example 3 by adding other metal pigments such as chromium-based and iron-based pigments, and as a result, the same effects as in Example 3 were obtained.

Example 5 Commercially available polyester film (thickness 50-100 μm)
When dry laminating the aluminum foil, dry lamination was carried out using an adhesive for dry lamination, such as an electrically insulating urethane adhesive containing approximately 1% by weight of titanium oxide (TiO2). In this way, a titanium oxide (TiOz) layer is formed between the synthetic resin thin film 2 and the aluminum foil that will become the strip conductor 3. After this, the aluminum foil is made into a strip conductor by an etching method. After forming the strip conductor 3 on the synthetic resin thin film 2, a polyethylene sheet (1 inch thick) as the dielectric 4 is glued facing one surface of the synthetic resin thin film 2 on which the strip conductor 3 is formed. ,
Further, an aluminum ground conductor 5 (thickness l mn ) is bonded to this polyethylene sheet by heat and pressure via the adhesive polyethylene film to form the structure shown in FIGS. 1 and 2.

The microstrip line antenna 1 configured in this manner showed no decrease in gain due to aging even when left outdoors.Although polyethylene was used as the dielectric material 4 in the above-mentioned embodiment, this The invention is not limited to polyethylene, and can be suitably implemented even when other materials are used as the dielectric 4.

Effects As described above, according to the present invention, an electrically insulating coating layer made of a material that absorbs ultraviolet rays is formed facing the outer surface of the dielectric material on which the conductor is disposed, so that ultraviolet rays do not reach the dielectric material. This prevents deterioration of the dielectric material due to changes over time. This would make it possible to improve the weather resistance of microstripline antennas, improving their reliability and longevity.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the basic structure of the microstrip line antenna 1, and FIG. 2 is a sectional view showing the basic structure of the microstrip line antenna 1. l...Microstrip line antenna, 2...
Synthetic resin thin film, 3...Strip conductor, 4...Dielectric, 5...Ground conductor Agent Patent Attorney Kei Nishi Part 1 Figure 2 Procedural Amendments March 22, 1985

Claims (1)

[Claims] A microstrip line antenna characterized in that an electrically insulating coating layer made of a material that absorbs ultraviolet rays is formed on the outer surface of a dielectric material on which a conductor is arranged.