JPH06140851A - High frequency amplifying semiconductor integrated circuit - Google Patents

Abstract

PURPOSE:To provide the high frequency amplifying semiconductor integrated circuit which can match the impedance with an external transmission line over wide bands. CONSTITUTION:An double step feedback wide band amplifier is constituted of bipolar transistors Q1 and Q2 and feedback resistors RE1, RE2 and RF. Then, an internal matching circuit 6 constituted of a resistor RI and inductance LI is provided between an output terminal TO and a power supply terminal TC as shown by a dotted line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency amplifying semiconductor integrated circuit, and more particularly to a feedback type bipolar transistor high frequency amplifier.

[0002]

2. Description of the Related Art In a conventional high frequency and high output amplification, a semiconductor integrated circuit is provided with high efficiency, for example, bipolar transistors Q1 and Q2 and feedback resistors RE1 and RE shown in FIG.
In the case of a two-stage feedback wideband amplifier composed of 2 and RF, as shown by the dotted line, the external matching circuit 6a of the external inductance LC is connected between the output terminal TO and the power supply terminal TC.

In this case, the external inductance LC acts as a load impedance of this amplifier, but since it has no resistance loss with respect to the output power, it has high power efficiency and is very suitable for a high output amplifier.

[0004]

However, in the conventional high-frequency amplifier semiconductor integrated circuit high-frequency amplifier, the output impedance is as high as 100 Ω to 1 KΩ, and when it is tangential to the 50 Ω transmission line used at normal high frequencies, There is a problem in that impedance mismatching occurs, there is a large amount of mismatch loss in output power, and the amplifier itself easily oscillates at high impedance.

[0005]

In a high frequency amplification semiconductor integrated circuit of the present invention, a resistance of polysilicon formed on an insulating layer of a semiconductor chip and an inductance formed by a spiral wiring layer are connected in series. , An internal matching circuit inserted between the power supply terminal and the output terminal.

[0006]

The present invention will be described below with reference to the drawings. FIG. 1 is an equivalent circuit diagram of an embodiment of the present invention, which is a two-stage feedback type high frequency amplification semiconductor integrated circuit composed of transistors Q1 and Q2.

In the circuit of this embodiment, the external matching circuit 6a between the output terminal TO and the collector power supply terminal TC of the semiconductor high frequency amplifier shown in FIG. 3 is moved to the internal matching circuit 6 on the chip and the series resistor RI is inserted. It is the same except that it was done.

The internal matching circuit 6 has a series resistance RI of 50 to 500Ω and an inductance LI of 1 to 50 nH,
FIG. 2 is a plan view of the semiconductor chip of FIG. 2A and a cross section taken along the line AA. As shown in FIG. 2B, the silicon oxide insulating layer 2 on the surface of the semiconductor substrate 1 is formed in the same manner as in the usual method for manufacturing a semiconductor integrated circuit.
The polysilicon resistance layer 3 of 50 to 500 Ω / □ formed above and the aluminum layers connected in the contact holes 4 on both ends of the insulation layer 2 with the insulating layer 2 sandwiched therebetween are formed into a wiring layer 5 spirally processed by etching. Both ends thereof are connected to the power source terminal TC and the output terminal TO by wiring inside the chip.

Normally, the output impedance of the transistor Q2 is about 100 to 500Ω, but impedance matching with an external transmission line of usually 50Ω or 75Ω is performed by the internal matching circuit of the resistor RI and the inductance LI.

The output impedance of the transistor Q2 has a frequency characteristic and is low on the high frequency side, but impedance matching can be performed over a wide band by adjusting and selecting the value of the inductance LI.

[0011]

As described above, according to the present invention, in the semiconductor integrated circuit of the high frequency amplifier, since the matching portion is provided inside the chip, it is possible to perform impedance matching with the external transmission line over a wide frequency band.

[Brief description of drawings]

FIG. 1 is an equivalent circuit diagram of an embodiment of the present invention.

2A and 2B are a plan view and a cross-sectional view taken along line AA of a semiconductor chip corresponding to an inductance portion of the circuit of FIG.

FIG. 3 is an equivalent circuit diagram of an example of a conventional high frequency amplification integrated circuit.

[Explanation of symbols]

 1 Semiconductor Substrate 2a, 2b Insulating Layer 3 Polysilicon Resistor 4 Contact Hole 5 Wiring Layer

Claims (1)

[Claims] 1. An internal matching inserted between a power supply terminal and an output terminal, which is connected in series with a resistance layer of polysilicon formed on an insulating layer of a semiconductor chip and an inductance formed by a spiral wiring layer. A high-frequency amplification semiconductor integrated circuit having a circuit.