JP3027883B2 - Microwave semiconductor amplifier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quasi-microwave / microwave band semiconductor amplifier used for satellite communication, terrestrial microwave communication, mobile communication, and the like. A microwave semiconductor amplifier is provided.

[0002]

2. Description of the Related Art Field effect transistors (hereinafter referred to as FETs) are used in transmitters of various communication devices in the quasi-microwave and microwave bands.
) Is often used. This microwave semiconductor amplifier is required to have high gain and high output. FIG.
This is a conventional high-output FET disclosed in Japanese Patent Publication No. 10 "Microwave integrated circuit". In this figure, 1 is an FET, 2
Is a gate electrode, and 3 is a drain electrode.

Next, the operation will be described. The RF signal input from the input terminal is distributed to each gate finger of the FET 1 by the gate electrode 2 and is amplified by the FET 1. The amplified signals are combined by the drain electrode 3 and extracted from the output terminal.

[0004]

A microwave semiconductor amplifier used for a transmitter of various communication devices requires high gain and high output performance. In a microwave semiconductor amplifier using an FET, the number of gate fingers of the FET is increased to increase the gate width in order to obtain a high output.
As a result, the length in the direction perpendicular to the gate finger of the FET increases, and the phase of the RF signal propagating through the gate electrode becomes F
It differs between when passing through the center of the ET and when passing through the periphery. For this reason, the signals are not efficiently combined, and the gain is reduced. In addition, when the gate width is increased, there is a problem that the impedance on the gate side is reduced and matching is difficult.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a high-gain, high-output microwave semiconductor amplifier.

[0006]

According to a first aspect of the present invention, in a microwave semiconductor amplifier using a field effect transistor, a gate electrode and a drain electrode are integrally formed on the same semiconductor substrate. A film that divides the gate electrode and the drain electrode into a plurality, and that sets the number of divisions of the gate electrode to be greater than the number of divisions of the drain electrode, and further connects predetermined adjacent electrodes of the divided electrodes. The resistor is formed on the semiconductor substrate.

According to a second aspect of the present invention, there is provided a microwave semiconductor amplifier using a field effect transistor, wherein the length of the gate finger of the field effect transistor located on each of different paths from the input terminal to the output terminal; The lengths of the electrode and the drain electrode are changed according to the length of the path.

[0008]

In the microwave semiconductor amplifier according to the first aspect of the present invention, the gate electrode and the drain electrode are formed integrally on the same semiconductor substrate, and the gate electrode and the drain electrode are provided in plural. And the number of divisions of the gate electrode is made larger than the number of divisions of the drain electrode, and further, a film resistor for connecting predetermined adjacent electrodes of the divided electrodes is formed on the semiconductor substrate. By doing so, if there is some variation in the characteristics of the FET connected to the adjacent electrode, it is possible to absorb the difference in the characteristics, and it is a small, high gain, high output, stable microwave semiconductor amplifier Can be realized.

Further, the present invention is configured as described above.
In the microwave semiconductor amplifier, the length of the gate finger and the length of the gate electrode and the drain electrode of the field effect transistor located on different paths from the input terminal to the output terminal are changed according to the path length of the path. Thus, the amount of phase change of the RF signal passing through the center of the gate electrode, the center of the FET, and the center of the drain electrode and the RF signal passing through the periphery of the gate electrode, the periphery of the FET, and the periphery of the drain electrode Since the difference in the amount of phase change due to the path difference can be compensated and the amount of change in the phase can be made substantially the same, a signal can be efficiently synthesized, and a high-gain, high-output microwave semiconductor amplifier can be realized.

[0010]

[Embodiment 1] FIG. 1 shows an FE used in the microwave semiconductor amplifier of the present invention.
FIG. 3 is a configuration diagram of one embodiment of T. In the figure, 1 is FE
T and 2 are gate electrodes and 3 is a drain electrode. FET
The gate and drain electrodes of an FET whose gate width is increased by increasing the number of gate fingers are divided into several electrodes so that RF signals of adjacent electrodes do not propagate to each other. Further, the number of divisions of the gate electrode 2 is larger than the number of divisions of the drain electrode 3.

Next, the operation will be described. The RF signal distributed and input to each gate electrode 2 is input to the gate finger of the FET 1. The distributed RF signal is F
At ET1, the signals are amplified with almost the same phase. The amplified RF signals are combined at the drain electrode 3, the outputs from the respective drain electrodes 3 are further combined at an external output circuit, and output from the output terminal.

FIG. 2 shows an FET in which the electrodes of the FET are not divided,
An example in which the FET in which the gate electrode is divided and the FET in which the gate electrode and the drain electrode are divided by the same number are respectively modeled, and an example of calculation of the maximum available power gain of the FET using the model is shown. From FIG. 2 it can be seen that splitting the electrodes improves the maximum available power gain of the FET. Further, even if the drain electrode is divided together with the gate electrode, there is almost no difference in gain. By dividing the gate electrode and the drain electrode in this way, the difference in the amount of phase change due to the path difference from the gate electrode to the drain electrode is reduced, and the amplified RF signal is amplified with substantially the same phase, and the signal is efficiently output. In addition to the combination, the impedance of the FET as viewed from each gate electrode is increased, so that matching can be easily performed, and a high-gain microwave semiconductor amplifier can be realized.

Further, when the number of divisions of the drain electrode is increased, more power combining circuits are required in the output circuit of the FET, so that there is a problem that the output power is deteriorated due to the loss of the power combining circuit. Therefore, by making the number of divisions of the drain electrode smaller than the number of divisions of the gate electrode, the power combining circuit is downsized, the loss of the power combining circuit is reduced, and a high-gain, high-output microwave semiconductor amplifier can be realized. effective.

In FIG. 1 shown in this embodiment, the ratio of division between the gate electrode and the drain electrode is shown as 2: 1. Of course, if the number of divisions of the gate electrode is larger than the number of divisions of the drain electrode. The division may be made at any ratio.

Embodiment 2 FIG. When fabricating an FET, characteristics may vary depending on the position even on the same wafer. This increases the gate width and increases the length of the FET.
There are cases where the characteristics of the ET also have some variations. In such a case, the difference in the characteristics may affect the characteristics such as the stable operation of the FET.

FIG. 3 shows another embodiment of the microwave semiconductor amplifier according to the present invention.
It is a block diagram of ET. In this FET, a resistor 4 is provided between each of a plurality of divided gate electrodes 2. By providing the resistor 4 between the adjacent gate electrodes 2 as described above, the difference between the characteristics of the adjacent FETs is
And the FET can perform a stable operation.
By simultaneously forming the resistor 4 with a thin film resistor or the like in the process of fabricating the FET, there is an effect that a small and stable microwave semiconductor amplifier can be realized. Although FIG. 3 shows an example in which the resistor 4 is provided only on the gate electrode 2, the same effect can be obtained by providing the resistor 4 on the drain electrode 3 side.

Embodiment 3 FIG. FIG. 4 is a configuration diagram of an FET used in a microwave semiconductor amplifier showing still another embodiment of the microwave semiconductor amplifier of the present invention. In this FET, the length of the gate finger 5 is different between the central portion and the peripheral portion of the FET 1. The amount of change in the phase of the microwave RF signal differs between the electrode portions of the gate electrode 2 and the drain electrode 3 and the gate finger 5 of the FET 1. Therefore, as shown in FIG. 4B, the phase change amount (θ1) when the RF signal passes through the center portion is shown.
+ Θ2 + θ3) and the length of the gate finger and the length of the electrode are set so that the amount of change (θ′1 + θ′2 + θ′3) when passing through the peripheral portion is equal, so that signal synthesis can be performed efficiently. Thus, there is an effect that a high-gain, high-output microwave semiconductor amplifier can be realized.

[0018]

As described above, according to the microwave semiconductor amplifier of the first aspect, the gate electrode and the drain electrode are formed integrally on the same semiconductor substrate, and the gate electrode and the drain electrode are provided in plural. Divided into
In addition, since the number of divisions of the gate electrode is greater than the number of divisions of the drain electrode, and furthermore, a film resistor for connecting a predetermined adjacent electrode of the divided electrode to the electrode is formed on the semiconductor substrate. The difference in the characteristics of the matching FET is absorbed by the film resistance, and the FET can perform stable operation.
A small, high-gain, high-output microwave semiconductor amplifier that operates stably can be obtained.

According to the microwave semiconductor amplifier of the present invention, the length of the gate finger and the length of the gate electrode and the drain electrode of the FET are changed, and the difference in the amount of phase change due to the path difference from the input terminal to the output terminal is changed. , The signal is efficiently synthesized, and a high-gain, high-output microwave semiconductor amplifier can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an FET used in a microwave semiconductor amplifier according to a first embodiment of the present invention.

FIG. 2 is a calculation result of a maximum available power gain of the FET showing the effect of the first embodiment of the present invention.

FIG. 3 is a configuration diagram of an FET used in a microwave semiconductor amplifier according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of an FET used in a microwave semiconductor amplifier according to a third embodiment of the present invention.

FIG. 5 is an FET used in a conventional microwave semiconductor amplifier.
FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Field effect transistor (FET) 2 Gate electrode 3 Drain electrode 4 Resistance 5 Gate finger

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kiyoharu Kiyono 325 Kamimachiya, Kamakura City Mitsubishi Electric Corporation Kamakura Works (72) Inventor Masahiko Funada 325 Kamimachiya Kamakura City Mitsubishi Electric Corporation Kamakura Works ( 56) References JP-A-2-100344 (JP, A) JP-A-3-250807 (JP, A) JP-A-62-292007 (JP, A) JP-A-1-166564 (JP, A) JP JP-A-63-202974 (JP, A) JP-A-3-270024 (JP, A) JP-A-61-104674 (JP, A) JP-A-64-17501 (JP, A) U.S. Pat. No. 5,132,641 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H03F 3/60 H01L 29/78 H01L 29/812

Claims (2)

(57) [Claims] 1. A field effect transistor microwave semiconductor amplifier using a, as well as integrally formed on the same semiconductor substrate Gate and drain electrodes, the <br/> gate electrode and the drain electrode more divided into, and form a number of divisions of the gate electrode by increasing the dividing number of the drain electrode, a further film resistor connected between the predetermined, adjacent electrodes and the electrodes of the divided electrodes on the semiconductor substrate A microwave semiconductor amplifier characterized in that: 2. A field effect transistor microwave semiconductor amplifier using a the length of the gate fingers of the field effect transistors located in different paths on the input terminal to the output terminal, a gate electrode and a drain collector
A microwave semiconductor amplifier, wherein the length of a pole is changed according to the length of the path.