JPS63126120A - Substrate for planar antenna - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a substrate for a planar antenna that has low dielectric loss and provides stable high gain.

[Prior art]

Planar antennas are being developed for satellite broadcast reception, and are characterized by being less affected by snow accumulation and wind pressure than Nozo Labo antennas.

However, at present, there is a problem that the gain is slightly low, and an improvement is desired.

Conventionally, fluororesin, glass fiber, and cross-linked ethylene have been used as dielectric materials in dielectric substrates for planar antennas. Such power visiting system materials still have a large dielectric loss, and need to be improved in order to put them into practical use as planar antennas.

On the other hand, regarding metal foils, the electrolytic steel foils that are mainly used are not sufficient in terms of gain and @tvj properties.

[Purpose of the invention]

The present invention was completed through various studies aimed at obtaining excellent high frequency characteristics that could not be obtained with conventional planar antenna substrates.

[Structure of the invention]

In the present invention, a fluororesin, a crosslinked polyolefin, a high melting point polyolefin, or the like can be used as the dielectric substrate. Specifically, 47-fluorinated tyrene polymer, tetrafluoroethylene-hexafluorinated propylene copolymer (FEP), 4-fluorinated ethylene-fluoroalkyl vinyl ether copolymer (PFA), ethylene.
Fluorine-based resins such as 47-chemically engineered tyrene copolymers (EFE'), radiation crosslinked, electron beam crosslinked or chemically crosslinked polyethylene, ultrahigh polymers with molecules of -1.5 million or more (1 to 4+) ethylene, talimethyl nitene, etc. Examples include preolefins obtained by polymerizing olefins having 4 or more carbon atoms, and these may be used alone, in a mixture, or in a layered combination.

The present invention is characterized in that oxygen-free copper foil is used as the gold foil for forming the microstrip element.

Oxygen-free copper foil is generally manufactured as follows.

(1) A method of reducing oxygen in a reducing gas such as a nitrogen-meritized carbon mixed gas to remove oxygen.

(1)) A method of melting electrolytic copper in a vacuum to remove oxygen.

Therefore, unlike the electrolytic steel foil that has been widely used in the past, the oxygen content is extremely low (3 to 10 ppm, while the electrolytic copper foil has an extremely low oxygen content of 3 to 10 ppm.
50 ppm), with little formation of electrically harmful Cu2O, it has excellent electrical conductivity and is particularly suitable for high frequency signal transmission, so when used as a microstrip element material for a planar antenna, it can be used with high gain. , a planar antenna with excellent dielectric properties can be manufactured. Here, an example of a method for manufacturing a general planar antenna substrate will be briefly described.

Thickness 1.0~2. A dielectric substrate is inserted between a ground conductor made of an Ovs aluminum plate and a metal foil such as copper foil with a thickness of 10 to 40 μm, and the temperature of the heater is 250 to 350°C and the pressure is 3.
It is integrally molded by heating and pressing under conditions of 0 to 50 k7/cm.

The dielectric substrate has a thickness of about 500 to 1000 μm,
750 to 850 μm is preferable.

It is preferable that the sheet-like materials constituting the dielectric substrate be subjected to corona discharge treatment in advance in order to improve their adhesion to each other or to metal.

In addition, in the present invention, P is present between the oxygen-free steel foil and the dielectric substrate, or between the ground conductor (aluminum plate) and the dielectric substrate.
By inserting a fluororesin sheet I such as FA or EFE, it is possible to easily integrate the adhesive.

〔Effect of the invention〕

According to the present invention, it is possible to obtain a double-sided metal-clad dielectric substrate for a planar antenna that is excellent in terms of high frequency properties, particularly dielectric properties and gain.

Therefore, as part of the future satellite broadcasting reception system,
This will make a major contribution to its spread.

〔Example〕

The planar antenna substrate according to the present invention will be described below using Examples and Comparative Examples.

Example 1 35 μm thick oxygen-free steel foil/800 μm thick cross-linked ethylene sheet) / 2. Ottrm-thick aluminum plates were laminated in this order, and the heater temperature was 300℃ and the pressure was 40kf7.
It was integrally molded by heating and pressurizing it at a pressure of cm.

Example 2 35 μm thick oxygen-free steel foil 150 μm thick PFA sheet/7
00 μm thick cross-linked polyethylene sheet 150 μm thick P
FA Sea) / 2.0 m thick aluminum plates were laminated in this order and integrally molded in the same manner as in Example 1.

Comparative Example 1 35 Atm thick electrolytic copper foil/800 μm thick crosslinked seriethylene sheet) / 2. , Om thick aluminum plates were laminated in this order and integrally molded under the same conditions as in Example 1.

The oxygen-free copper foil used was Hitachi Cable ■g OFC foil, and the electrolytic copper foil used was Furukawa Circuit Foil ■.

The adhesive surface of the aluminum plate was anodized to improve adhesive strength.

For the planar antenna substrate obtained on each side, the galvanic rate,
The dielectric loss tangent and gain were measured and the results are shown in Table 1.

It can be seen that the substrates obtained in Examples 1 and 2 have a low dielectric constant, a low dielectric loss tangent, and a high gain.

Chapter 1 Table The measurement method is as follows.

Dielectric constant, electric dissipation tangent: The copper foil surface was etched to form a strip line, and measured at a frequency of 12 Gl (z).

Gain: Determined through comparative measurements with a pyramidal horn (standard antenna).

(Refer to Koguchi and Ota, “Microwave and Millimeter Wave Measurement,” Corona Publishing, December 10, 1978, pp. 215-216)

Claims (1)

[Claims] (1) A planar antenna substrate in which the entire back surface of a dielectric substrate is used as a ground conductor and a metal foil for forming a circularly polarized wave dissipating microstrip element is provided on the surface, wherein the metal foil is an oxygen-free steel foil. A planar antenna substrate characterized by: