JPS631202A - Flat antenna and its production - Google Patents

Abstract

PURPOSE:To ensure the high gains and to improve the productivity of flat antennas by assembling an earth conductor substrate made of a metallic flat plate, a flexible feed circuit film and a flexible radiation circuit film with intervention of air layers. CONSTITUTION:An earth conductor substrate 1 uses an aluminum plate, for example, with 2-4mm thickness. A feed circuit film 2 uses a base film of polyphthalate, for example, with 50-10mum thickness and contains a strip line 3 made of a copper foil (20-40mum). A radiation circuit film 5 uses the same base film as the film 2 and contains a slot 4 made of a copper foil (20-40mum). Both films 2 and 5 are fixed to the substrate 1 by adhesion at their both sides respectively. The spacers 6 and 7 are provided among these films 2 and 5 and the substrate 1 to form air layers. Thus a dielectric substance and a honeycomb member can be omitted to eliminate the dielectric substance or conductor loss. Furthermore the production of a flat antenna is also facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a flat antenna used for satellite broadcast reception, microwave communication, etc., and a method for manufacturing the same.

(Background Art) Conventionally, a flat antenna with a so-called triplate structure connects a grounded conductor substrate with a dielectric interposed therebetween.

The feeding circuit and radiation circuit were combined. however,
In this unconventional configuration, dielectric loss and conductor loss are large, resulting in a decrease in the antenna gain.In addition, a honeycomb structure made of a material with a low dielectric constant is interposed between them to create an air layer. A so-called suspended structure has been attempted, but low dielectric constant honeycomb materials are expensive and difficult to manufacture, so they are currently only used for limited purposes.

(Object of the Invention The present invention was proposed to improve the above-mentioned drawbacks, and an object of the present invention is to provide a flat antenna with high gain and excellent manufacturability.

(Disclosure of the Invention) The present invention provides a four-piece grounding board made of a metal flat plate; 1; a flexible power feeding circuit film in which a stretched power feeding strip line is formed with an air layer interposed on the grounding conductor substrate; The gist of the invention is a flat antenna characterized in that a flexible radiation circuit film in which slots are arranged and formed with an air layer interposed on the above-mentioned feeder circuit film is provided.

Furthermore, the present invention includes a step of adhesively fixing at least both sides of a flexible power supply circuit film having a strip line formed thereon on a ground conductor substrate such as a metal flat plate, and then a step of fixing at least both sides of a flexible power supply circuit film having a strip line formed thereon. a step of adhesively fixing both sides to the ground conductor board on the outside of the part where the power supply circuit film contact layer is fixed; and a step of adhesively fixing the power supply circuit film and the ground conductor board and the radiation circuit film. A method for manufacturing a flat antenna, comprising the steps of: inserting a spacer between the film and the ground conductor board, stretching both films, and forming an air layer between the film and the ground conductor board. This is the gist of the invention.

The present invention will be described in detail below with reference to the drawings. Figure 1 is a perspective view of a flat antenna according to an embodiment of the present invention, and Figures 2 and 3 are cross-sectional views for manufacturing process*. It is.

In FIG. 1, reference numeral 1 denotes a ground conductor board, which is, for example, an aluminum plate with a thickness of 2 to 4 m. 2 is a power supply circuit film, for example, polyethylene terephthalate (50 to 1
00μm thickness)? Strip line 3 as base film
(copper foil 20 to 40 μm thick) is formed. 5 is a radiation circuit film, for example, polyethylene terephthalate (50 to 100 μmW) as a base film,
A slot 4 (copper foil 2o to 40 μm thick) is formed.

Both of the above-mentioned films are adhesively fixed on the ground conductor substrate on both sides.

6 and 7 are spacers, which are provided between the power supply circuit film 2 and the ground conductor board 1 and between the radiation circuit film 5 and the ground conductor board 1.
This is to form a predetermined air layer between the two.

8 is a coaxial connector for connecting the strip line 3 and the external transmission circuit (1 omitted) of the flat antenna board,
S) It is attached to the feed point A part of the IJ tube line. 9 is an adhesive.

Next, the manufacturing method will be explained.

First, the construction shown in FIG. Stack the 5 radiation circuit films and glue the outer peripheries of the power supply circuit film 2 and the radiation circuit film 5 with adhesive 9.
a + 9 b + 9 c + ” d to adhere to the ground conductor board 1. In this case, the radiation circuit film 5 is
The feeder circuit film 2 is bonded to the ground conductor substrate 1 outside the bonding location to the ground conductor substrate 1. Adhesion can be done by either a room temperature curing type or a heating adhesive type, but it is desirable to pressurize the power supply circuit film 2 and the radiation circuit film 5 in order to tightly layer them on the ground conductor substrate 1 without wrinkles.

After the adhesion is completed, attach the spacer 6 shown in Figure 3.
a, 6b' are inserted between the power supply circuit film 2 and the ground conductor substrate 1, and the power supply circuit film 2 made of a flexible film is expanded to form an air layer.

Similarly, spacers 7a and 7b are inserted between the radiation circuit film 5 and the ground conductor substrate 1, and the radiation circuit film 5 is expanded to form an air layer. Therefore, the thickness of the spacer is set according to the thickness of the air layer.

By the above method, a flat antenna substrate is formed,
Finally, connect the coaxial connector 8 to the feed point A to complete the flat antenna.

In the above manufacturing method, there may be a few problems, so they will also be explained.

(I) If the thickness of the air layer is too thick and force is applied to stretch the film, there is a possibility that circuit deformation, dimensional change, and deformation (warping) of the ground conductor board may occur.

In that case, when adhering as shown in FIG. 4(a), for example, insert a release paper 10 or other casing for thickness adjustment between the film 2 and the ground conductor substrate 1, as shown in FIG. 4(b). : sea urchin,
The next step is to adjust the force applied during expansion.

Q[) The antenna circuit may be attached at two locations on the left and right, but it may also be attached at four locations on the front, back, left and right. However, in the case of four locations, it is necessary to provide a non-adhesive portion in order to insert the base.

(2) If the adhesive strength is weak, it may come off due to the force of stretching. In this case, attach the adhesive part as shown in Figure 5.
It is also possible to reinforce it with 1 etc.

(Effect of the invention) As explained above, 72:,! According to the present invention, the antenna is formed in a triplate structure without using a dielectric material or a dielectric material, so that a high antenna gain can be obtained without dielectric loss or ring loss. This has the advantage of being easy to manufacture.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the flat antenna of the present invention, FIGS. 2 and 3 show a method of manufacturing the flat antenna of the present invention, and FIGS. 4 and 5 show other embodiments.

Claims (2)

[Claims] (1) A ground conductor board made of a flat metal plate, a flexible power supply circuit film in which a stretched power supply strip line is formed with an air layer interposed on the ground conductor board, and a flexible power supply circuit film formed on the power supply circuit film. and a flexible radiation circuit film in which slots are arranged in an array with an air layer interposed therebetween. (2) A step of adhesively fixing at least both sides of a flexible power supply circuit film with a strip line formed thereon on a ground conductor substrate made of a flat metal plate, and then at least both sides of a flexible radiation circuit film with a slot formed therein. on the ground conductor board, on the outside of the place where the power feeder circuit film is adhesively fixed, and between the power feeder circuit film and the ground conductor board and between the radiation circuit film and the ground conductor board. A method for manufacturing a flat antenna, comprising the steps of: inserting a spacer between the two films, and stretching both films to form an air layer between the two films and the ground conductor substrate.