Research On S-band High-efficiency Class F Power Amplifier Technolog

Under the background of reducing power consumption,realizing energy saving,and with the advent of various new materials such as Ga As and Ga N transistors,high-efficiency broadband power amplifier has become a hot research topic at home and abroad.Harmonic control technology is one of the methods to improve the efficiency of power amplifier.This paper mainly designed the high efficiency F class power amplifier,analyzed its basic principle in detail,optimized the efficiency and bandwidth index.The main content of the paper is as follows:In this paper,the research background and current situation of high efficiency broadband amplifier are investigated,and the transistor types and main indexes of power amplifier are introduced,and the amplifier is classified according to the traditional type and high efficiency type.Secondly,this paper studies the basic principle of F class power amplifier,deduces its voltage and current waveform formula in detail and analyzes its efficiency.A class F power amplifier with operating frequency of 3GHz is developed,witch output power is greater than10 W,and the efficiency is 80%.In the design process improved the extraction of the best impedance method,considering the easily neglected in the traditional design of the input harmonics,improve the matching circuit,solved the problem of harmonic impedance matching point deviation,combining bias circuit and harmonic control circuit.Then,aiming at the problem that the working bandwidth of class F power amplifier,the basic principle of broadband continuous class F power amplifier is studied,and makes improvements to the voltage equation to give a hybrid continuous F power amplifier theory,based on the theory of impedance solution space than continuous class F amplifier is more extensive.According to the theory,a hybrid F class power amplifier with operating frequency of 2.3～3.7GHz and 10 W output power and 70% efficiency is designed.In the process of designing the matching circuit,the source-pull technology and Chebyshev low-pass filter matching method are adopted.Finally,the simulation and actual test results of two power amplifiers are given.The test results show that the designed power amplifier can meet the requirements of the index,verify the related theory of harmonic control,prove the feasibility of the scheme,and has better performance than the published same type of power amplifier.