JPH0794649A - Gaasfet package - Google Patents

Abstract

PURPOSE:To realize a package for FET in which the NF matching circuit for high frequency amplifier circuit is made compact. CONSTITUTION:Characteristic impedance at the gate terminal of a FET is increased by setting the lead width and the lead length thereof, respectively, at 0.2mm or less and 10mm. When such gate terminal is employed as a part of NF matching circuit, the size thereof can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low noise GAASFET package used in a microwave band amplifier.

[0002]

2. Description of the Related Art A conventional GAASFET has a gate terminal 1
And a drain terminal, and a source terminal are two.
The gate width of the AASFET is a package having a lead width of 0.5 mm and a lead length of 4 mm. (Eg NEC
Semiconductor Catalog NE76084) Figure 2 shows the conventional GAAS
It is an outline view showing a package of FET. In FIG. 2, GAASFET 1, gate 2 of GAASFET 2, terminal 2, drain terminal 3 of GAASFET 3, GAASFET
Source terminal 4 is shown.

In the microwave band amplifier using the GAASFET described above, there is known a microstrip circuit configuration in which a distributed constant matching circuit composed of a microstrip line is connected to the gate terminal and the drain terminal of the GAASFET and the source terminal is grounded. Has been. GA
FIG. 3 shows an example of a microwave band amplifier using ASFET. In FIG. 3, 5 is a microstrip line, 6 is a microstrip pattern for lease grounding,
Reference numeral 7 is a substrate, and 8 is a carrier. Input side matching circuit 5a
Is connected to the line with the next lowest characteristic impedance (wider than the lead width) next to the gate terminal, and then connected to the line with the next highest characteristic impedance (narrower line width than the lead width). It has a two-tiered structure.

[0004]

[Problems to be Solved by the Invention] Conventional GAASFET
In the package, since the characteristic impedance of the gate terminal of the FET is low, if an impedance converter is connected to the gate terminal to obtain the best point of the noise parameter Popt of the FET characteristic, the noise figure (hereinafter NF) matching circuit is 2 There was a problem that it was more than a stepped structure. The present invention is intended to solve the above problems, and an object thereof is to realize a GAASFET package in which the best value of NF is obtained and the NF matching circuit has one stage.

[0005]

In order to solve the above problems, the GAASFET package according to the present invention is characterized in that the lead width of the gate terminal is 0.2 mm or less and the lead length is 10 mm.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings.
FIG. 1 is an outline view of a GAASFET package according to an embodiment of the present invention. In FIG. 1, 1 is a FET, 2 is a gate terminal, 3 is a drain terminal, and 4 is a lease terminal. In the package of the GAASFET according to the present invention, the layout of the lead terminals is the same as that of the conventional one, but by setting only the width of the gate terminal to 0.2 mm or less, the microstrip line connected to the gate terminal of the GAASFET can be freely set in the high frequency amplifier. The optimum NF matching circuit can be realized. Further, since the gate terminal has a high impedance, the terminal itself can be used as a part of the matching circuit, and the NF matching circuit can be configured in one stage. As the length of the gate terminal is longer, the lower frequency band can be applied, but the physical strength is taken into consideration due to its thin width of 0.2 m.
It is desirable to set it to mm or more.

[0007]

As described above, the low noise GA according to the present invention
Since the ASFET package has a lead width of 0.2 mm or less and a lead length of 10 mm at the gate terminal of the FET,
The effect is that an optimum and small NF matching circuit can be obtained.

[Brief description of drawings]

FIG. 1 is an outline view of a GAASFET according to an embodiment of the present invention.

FIG. 2 is an external view of a conventional GAASFET.

FIG. 3 is a configuration diagram of a microwave band amplifier using a conventional GAASFET.

[Explanation of symbols]

 1 FET 2 Gate Terminal 3 Drain Terminal 4 Lease Terminal 5 Microstrip Line 6 Microstrip Pattern for Source Grounding 7 Substrate 8 Carrier

Claims (1)

[Claims] 1. A hermetically sealed package of circular and rectangular GAASFETs having a gate terminal, a drain terminal, and a source terminal, wherein the lead width of the gate terminal is 0.2 mm.
Hereinafter, the lead length is 10 mm or more
AASFET package.