JPH05121975A - Microwave amplifier - Google Patents

Abstract

PURPOSE:To prevent spurious oscillation and to surely connect a separator and a ground electrode of a microwave active element to ground. CONSTITUTION:A circuit pattern 5a provided with an input terminal I, a circuit pattern 5b provided with an output terminal O, and a grounding circuit pattern are formed respectively to a dielectric board 1. A gate electrode 2C of a microwave active element 2 connects to the circuit pattern 5a, a drain electrode 2D connects to the circuit pattern 5b, and a source electrode forming a ground electrode 2S connects to the ground circuit pattern respectively. A metal-made separator 3 is arranged onto the dielectric board 1 so that its center chip is placed above the microwave active element 2. A metallic fixture 6 uses the elasticity to press the ground electrode 2S of the microwave active element 2 with a lower face of leg pieces 6b, 6b and the center chip of the separator 3 and both side chips are inserted between clip pieces 6a, 6a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave amplifier configured in a microwave utilizing device such as a satellite broadcasting BS converter.

[0002]

2. Description of the Related Art As a device for constructing a low noise amplifier in the microwave band, a GaAs FET (gallium.
Microwave active devices such as arsenic field effect transistors) and HEMTs (high electron mobility transistors) are commonly used. As a microwave amplifier, it is general that the above-mentioned microwave active elements are mounted on a dielectric substrate having a circuit pattern formed on the upper surface, and the dielectric substrate and the microwave active elements are covered with a metal case. is there.

In the above microwave active element, when the source electrode is grounded, the gate electrode is used as the input, and the drain electrode is used as the output, unnecessary oscillation may occur due to spatial coupling between the input and output. There is a method of using a metal separator for this purpose. FIG. 3 shows a conventional example using this separator. In the case of this conventional example, the microwave active element is mounted in parallel with the ground electrode 2 _S of the microwave active element 2 mounted on the circuit pattern of the dielectric substrate 1. Two
A gate-shaped metal separator 3 is arranged on the upper part of the.

FIG. 4 shows another conventional example. In this conventional example, the lower ends of both leg pieces of the metallic separator 3 are soldered 4 to the ground electrode 2 _S of the microwave active element 2.

[0005]

In the conventional example shown in FIG. 3,
In order to enhance the effect of preventing oscillation, ideally, the separator 3 should be brought into direct contact with the ground electrode 2 _S of the microwave active element 2. There is a problem in height variation of the ground electrode 2 _S of the wave active element. If the pressure is too strong, the microwave active element 2 may be destroyed.

Further, in the conventional example of FIG. 4, when soldering the separator 3, there is a problem in that heat escapes and is difficult to apply, and so-called soldering is not surely performed in a soldered state. Further, since the microwave active element 2 such as the HEMT is easily electrostatically destroyed, there is a problem that it is difficult to replace the parts if the microwave active element 2 is electrically broken.

The present invention has been made in view of the above problems, and its purpose is to prevent unnecessary oscillation and to reliably ground the separator and the ground electrode of the microwave active element. Another object of the present invention is to provide a microwave amplifier which can easily replace parts when the microwave active element is electrostatically destroyed.

[0008]

In order to achieve the above object, the present invention is directed to a microwave amplifier comprising a circuit pattern formed on a dielectric substrate and a microwave active element mounted on the circuit pattern. In the third aspect of the present invention, there is provided a metal fitting integrally provided with a portion sandwiched between and attached to the metallic separator disposed above the microwave active element and a portion for pressing the ground electrode of the microwave active element.

[0009]

According to the present invention, therefore, the separator and the ground electrode can be reliably grounded through the metal fittings without soldering due to the above configuration. Also, with the separator and metal fittings,
It is possible to cut off spatial coupling between the input and output of the microwave active element and prevent unnecessary oscillation of the microwave amplifier.

[0010]

EXAMPLES The present invention will be described below with reference to examples. FIG. 1 shows an embodiment of the present invention, in which a circuit pattern 5a having an input end I, a circuit pattern 5b having an output end O, and a circuit pattern for grounding are formed on a dielectric substrate 1, respectively. The gate electrode 2 _G of the microwave active element 2 made of HEMT is connected to the circuit pattern 5 a, the drain electrode 2 _D is formed on the circuit pattern 5 b, and the ground electrode 2 _S is formed on the circuit pattern for grounding. The microwave active elements 2 are mounted by connecting the respective source electrodes.

The substantially gate-shaped metal separator 3 is arranged on the dielectric substrate 1 with the central piece positioned above the microwave active element 2. The leg piece on one side of the separator 3 is shortened so as to float above the dielectric substrate 1 and not come into contact with the circuit pattern of the dielectric substrate 1. As shown in FIG. 2, the metal fitting 6 bridges two sandwiching pieces 6a, 6a parallel to each other on both sides at the center of the lower ends of the sandwiching pieces 6a, 6a, and diagonally below both sides of the bridging piece. legs integrally with the 6b, 6b which has been configured to extend and the bracket 6 legs 6b while using the elasticity, the lower surface of 6b from above ground electrodes 2 _S of the microwave active element 2 While being pressed, the central piece portion and both side piece portions of the separator 3 are sandwiched between the sandwiching pieces 6a, 6a to be attached.

Thus, the separator 3 is grounded to the ground electrode 2 _S via the metal fitting 6 to prevent unnecessary oscillation.

[0013]

According to the present invention, in a microwave amplifier comprising a circuit pattern formed on a dielectric substrate and a microwave active element mounted on the circuit pattern, a metallic amplifier disposed above the microwave active element is used. Since a metal fitting integrally provided with a portion sandwiched between the separator and a portion for pressing the ground electrode of the microwave active element is provided, the separator and the ground electrode can be connected via the metal fitting without soldering with variations. Grounding can be reliably performed, and the input and output of the microwave active element can be spatially cut off by the separator and the metal fitting, and unnecessary oscillation of the microwave amplifier can be prevented. Since the metal fittings can be easily removed, it is possible to remove the metal fittings if the microwave active element is electrostatically destroyed. An effect that can be easily replaced.

[Brief description of drawings]

FIG. 1A is a top view of an essential part of an embodiment of the present invention with a part thereof omitted. (B) is sectional drawing of the one part main part which abbreviate | omitted one Example of this invention.

FIG. 2 is a perspective view of a metal fitting used in one embodiment of the present invention.

FIG. 3 is a cross-sectional view of a conventional example with some parts omitted.

FIG. 4 is a partially omitted cross-sectional view of another conventional example.

[Explanation of symbols]

1 Dielectric Substrate 2 Microwave Active Element 2 _S Ground Electrode 2 _D Drain Electrode 2 _G Gate Electrode 3 Separator 5a Circuit Pattern 5b Circuit Pattern 6 Metal Fitting 6a Clamping Piece 6b Leg Piece I Input Terminal O Output Terminal

[Procedure amendment]

[Submission date] December 26, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction content]

[0005]

In the conventional example shown in FIG. 3,
To increase the effect of oscillation prevention, ideally,
Ground electrode 2 of active element 2_SThe separator 3 directly
The size of the separator 3 should be such that it makes contacttolerance
And the ground electrode 2 of the microwave active element during mounting_SHeight of
There was a problem with the variation of. Hold down with too strong pressure
Doing so will destroy the microwave active element 2.
I was afraid.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masamoto Keiji 1048, Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works Co., Ltd. (72) Yoshitaka Kimura, 1048, Kadoma, Kadoma City, Osaka Matsushita Electric Works Co., Ltd. Within

Claims (1)

[Claims] 1. A circuit pattern formed on a dielectric substrate,
In a microwave amplifier composed of a microwave active element mounted on this circuit pattern, it is sandwiched between metal separators arranged above the microwave active element and is attached to a portion to press the ground electrode of the microwave active element. A microwave amplifier, characterized in that it is provided with a metal fitting integrally provided with a part.