Research Of Microwave Power Amplifier Linearization Technology

Now,wireless mobile communication technology is developing at high speed,and highpower amplifiers are widely used in civil mobile communications,military command systems,broadcast television,aerospace and other fields.As the core component of the communication system,the performance index of the output signal of the high-power amplifier whose operating frequency is microwave or even millimeter wave has an important impact on the entire communication system,and good performance has a better guarantee for the transmission quality of the entire communication system.However,due to the inherent characteristics of the device,design method,and process,as the input power increases,the power amplifier always gradually changes from linear to nonlinear state,and nonlinear distortion occurs,which seriously affects the output characteristics.In the past,the power amplifier was retreated from the saturated working state to the linear region simply by power back-off to obtain a better linearity index.However,as the requirements of modern wireless communication systems for the linearity of power amplifiers are gradually increasing,the output power of power amplifiers is getting larger and larger,and the method of using power back-off to improve nonlinear distortion cannot meet the needs of practical applications.On the premise of not affecting the output power of the power amplifier,linearization technology is proposed to meet the linear index of the output signal,and the linearization technology is used to ensure that the power amplifier can still meet the linearity requirements of the communication system when the output is close to saturation.At present,China started late,and foreign countries have begun to improve the nonlinear distortion of power amplifiers decades ago.Different scholars have proposed various solutions based on the principle of nonlinear generation of amplifiers,and have also achieved fruitful results.However,the current linearization technology for millimeter wave solid-state power amplifiers,especially broadband power amplifiers,is still in the research and development stage.This article is to improve the research of linearization technology,especially predistortion technology,to improve the Ka-band solid-state communication power amplifier.In this paper,through the analysis of Schottky diodes and the improvement of the circuit structure on the basis of the classic principle circuit,the use of RF simulation software for calculation simulation and processing of the physical,and finally passed a cascade test with a gallium nitride-based Ka-band 50 W amplifier.The test results show that after the linearizer is added,the power amplifier is at 3dB of saturation back-off,and the third-order intermodulation index is improved by close to 6-7dB,reaching less than-25 dBc,which can meet the needs of the communication power amplifier.