Temperature compensating circuit of power amplifier

Abstract

This application discloses a temperature compensating circuit of a power amplifier. The temperature compensating circuit performs temperature compensation on a constant bias current; or converts a constant bias voltage into a current, performs temperature compensation, and then provides a base electrode of a power tube with a temperature-compensated bias current. The temperature compensation comprises: when the power tube works normally and is at a temperature below a threshold temperature, making a current variation of the collector electrode of the power tube positively correlated with a temperature variation; and when the power tube works normally and is at a temperature above the threshold temperature, or when the power tube is mismatched and works abnormally, making the current variation of the collector electrode of the power tube negatively correlated with the temperature variation. According to the temperature compensating circuit of the power amplifier, reliability problems such as an output power variation, a stability variation, linearity deterioration, and overheating and overburning caused when a temperature of the power amplifier varies are resolved.

Description

technical field [0001] The present application relates to a bias circuit of a power amplifier, in particular to a temperature compensation circuit therein. Background technique [0002] RF power amplifiers usually use heterojunction bipolar transistors (HBT), complementary metal oxide semiconductor transistors (CMOS), high electron mobility transistors (HEMT), etc. as amplifying transistors, called power transistors. The power tube requires a certain DC voltage and / or DC current during operation, which is called biasing. If the bias circuit provides DC voltage for the power tube, it is called voltage bias mode. If the bias circuit provides DC current for the power tube, it is called current bias mode. Most of the existing RF power amplifiers use voltage bias. However, new generation communication standards such as 4G and 5G have put forward new performance requirements for RF power amplifiers. Traditional voltage bias RF power amplifiers can no longer meet the new performa...

AI Technical Summary

Problems solved by technology

This document is mainly applicable to self-bias circuits or voltage bias methods, and it is difficult to achieve precise control of the output power of the power tube

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