The L-band GaNHEMT Broadband High Power Amplifier Design And Implementation

With the development of wireless communication technology,The wireless communication system based on Software Defined Radio(SCA) requirements with multi-band, multi-mode capability and support for high-speed data communications. To meet this requirement, The power amplifier must be capable of working on broadband spectrum, with sufficiently high linearity and efficiency specifications. This article is a broadband power amplifier design based on GaN HEMT,aims to solve broadband, high linearity and high-efficiency Problems.The third generation of wide bandgap semiconductor GaN HEMT with a high power density, high matching impedance as soon as high electron mobility advantage, It is an important Power semiconductors material for the development of high-efficiency compact broadband linear amplifier. This paper uses GaN HEMT transistors, based on GaN HEMT large-signal model, According to the overall design specifications, developed the L-band broadband power amplifier.The main work is as follows:Firstly, Understanding the current situation and research directions in the field of the broadband power amplifier design. Researching The basic design theory of broadband power amplifier.include basic design specifications, large-signal nonlinear analysis method, Characteristics of Multiple broadband matching network.Secondly,Complete the overall design and Module specifications decomposition. Then selecting CREE GaN HEMT transistor and ROGERS RO4350 high frequency plates as PCB plate. Considering the system gain, output power and linearity specifications, the final plan can be summarized as three amplifier cascade, Which consists of a pre-driver stage, HPF, driver and final stage amplifier.the final stage amplifier uses structure of balanced synthesis, It can improve the output power and linearity specifications, With best output port reflection coefficient, Ensure the overall stability of the amplifier.Third, the broadband matching circuits are designed. In 1-2GHz frequency range, Broadband Matching network structure is multiple minor matches and gradient line, That is the multi-step impedance transformer and In paralleled of Open or short microstrip line. Using GaN HEMT large-signal model, Continuous optimization matching parameters in ADS harmonic balance and co-simulation environment until it reaches the design specifications.Finally, designed the broadband matching network and the L-band broadband power amplifier.Fourth, testing the PA, including test system solutions, commissioning processes and testing methods, comparative analysis of the actual test results and conclusions.When amplifier was measured at last,In the 1-2GHz frequency band range,the PEP output power greater than 60 W,Efficiency higher than 48.1%,the third-order intermodulation is Greater than26.5dBc.When tested using QAM16 signal,The output average power is greater than 20 W,the EVM <3.5%,ACPR>30.5dBc. From the test results,Actual test results and simulation results are consistent,the entire design meets the requirements.