JPH06140822A - Planar antenna - Google Patents

Abstract

PURPOSE:To reduce a dielectric lose and to provide high sensitivity by containing a foaming plastic film in a supporter concerning the planar antenna provided with a reception circuit on the planar supporter. CONSTITUTION:The reception element of the planar antenna is prepared by providing the layer of a conductive material on the supporter and forming the reception circuit. The conductive material layer is formed by adhering the metal foil of aluminium or copper onto the supporter with an adhesive or sticking metal powder, etc., with any method such as vapor deposition or sputtering. On the other hand, concerning a method for forming the circuit on the conductive material layer, a circuit forming part is covered with resist resin or the like, the conductive material is removed by alkali or acid corrosion and afterwards, the resist resin is removed or a mechanically stamped conductive material forming circuit is adhered by the adhesive agent. Concerning the planar antenna prepared like this, the dielectric loss is reduced, radio wave transmissivity is improved and therefore, high sensitivity is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar antenna used for satellite broadcasting reception and the like.

[0002]

2. Description of the Related Art Conventionally, a plastic film such as a polyester film has been used as a support for a receiving element of a planar antenna for satellite broadcast reception. However, these plastic films have the drawbacks of high dielectric loss and low radio wave transmittance.

[0003]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a planar antenna having a low dielectric loss factor and a high radio wave transmission factor, and therefore a highly sensitive receiving element.

[0004]

The object of the invention is achieved by a planar antenna in which a receiving circuit is provided on a planar support, said support comprising a foamed plastic film. It As the support used in the present invention, a foamed plastic film having a thickness of 30 to 1000 μ is used. As a particularly preferred support, a laminate comprising a foamed plastic film and non-foamed plastic films laminated on both surfaces thereof is preferred. As the plastic, polyester such as polyethylene terephthalate, polyolefin such as polyethylene, polypropylene, or the like can be used. The most preferable polyester is polyethylene terephthalate. The apparent specific gravity of the laminate of foamed polyethylene terephthalate and non-foamed polyethylene terephthalate is 0.8 to 1.2, preferably about 0.9 to 1.1, and particularly preferably about 0.9.

The receiving element of the planar antenna of the present invention can be manufactured by providing a layer of a conductive material on a support and forming a receiving circuit. The conductive material layer can be easily formed by adhering a foil of metal such as aluminum or copper to the support with an adhesive, or by adhering metal powder or the like by a method such as vapor deposition or sputtering. As a method for forming a circuit on the conductive material layer, the circuit forming portion is covered with a resist resin or the like, and the conductive material is removed by corrosion with an alkali or an acid, and then the resist resin is mechanically removed. A conventional method such as bonding the die-cut conductive material forming circuit with an adhesive can be used.

[0006]

Since the planar antenna of the present invention uses the one containing foamed plastic as the support, it has a low dielectric loss factor and high sensitivity.

[0007]

Example 1 A rolled copper foil having a thickness of 18 μ was adhered to a foamed polyethylene terephthalate having a thickness of 50 μ (polyester film Lumira (trade name): three-layer laminate specific gravity 0.9 manufactured by Toray Industries, Inc.) with an olefin adhesive. . A circuit with a line width of 1.5 mm and a length of 26 cm is printed on the copper foil surface with resist resin ink, and after etching, the resist resin is removed,
The receiving element was manufactured.

A receiving element was similarly prepared using non-foamed polyethylene terephthalate instead of foamed polyethylene terephthalate. 12 of 2 types of receiving elements
A GHz plane traveling sound wave was passed. The gain of the transmitted sound wave was 0.32 dB (loss rate 3.2%) when using the foamed polyethylene terephthalate, while it was 0.45 when using the non-foamed polyethylene terephthalate.
It was dB (loss rate 4.5%).

[0009]

Example 2 An aluminum foil having a thickness of 10 μm was bonded to a foamed polyethylene terephthalate having a thickness of 50 μm (polyester film Lumira (trade name): three-layer laminate, specific gravity: 0.9, manufactured by Toray Industries, Inc.) with an olefin adhesive. A circuit having a line width of 1.5 mm and a length of 26 cm was printed on the surface of the aluminum foil with a resist resin ink, and after etching, the resist resin was removed to manufacture a receiving element.

A receiving element was similarly prepared using non-foamed polyethylene terephthalate instead of foamed polyethylene terephthalate. 12 of 2 types of receiving elements
A GHz plane traveling sound wave was passed. The gain of the transmitted sound wave was 0.60 dB (loss factor 6.0%) in the case of using the expanded polyethylene terephthalate, whereas it was 0.76 in the case of using the non-expanded polyethylene terephthalate.
It was dB (loss rate 7.6%).

The results of the above examples show that the planar antenna of the present invention has higher sensitivity than the conventional one.

Claims (5)

[Claims] 1. A planar antenna having a receiving circuit provided on a planar support, wherein the support includes a foamed plastic film. 2. The planar antenna according to claim 1, wherein the support is a laminated body composed of a foamed plastic film and non-foamed plastic films laminated on both surfaces thereof. 3. The planar antenna according to claim 1, wherein the plastic is polyester. 4. The planar antenna according to claim 3, wherein the polyester is polyethylene terephthalate. 5. The planar antenna according to claim 4, wherein the apparent specific gravity of the laminated body is about 0.9.