Research On GaAs-based Millimeter-wave Predistortion Linearization Technology

With the accelerated development of wireless communication,some efficient digital modulation techniques have been widely used in satellite communication systems.The peak-to-average power ratio of the signal tends to increase,resulting in nonlinear distortion in the power amplifier and degrading the performance of the communication system.In engineering,a popular method to improve the linearity of power amplifier is the analog predistortion linearization technique.At present,in domestic,most of the analog predistorters is implemented by the hybrid microwave integrated circuit.However,in some applications with higher requirements for size,reliability and cost,such as satellite communications,monolithic microwave integrated circuits have greater advantages.In this thesis,we focus on the analog predistortion technology and the implementation of millimeter-wave analog predistortion linearizers using Ga As process.The main research results of this thesis are as follows.In this thesis,a new reflective analog predistorter structure based on Schottky diodes is proposed by using vector synthesis technique,whose compensation of amplitude and phase can be tuned independently.It can improve the strong correlation between the gain and phase of the traditional analog predistorter used in the solid-state power amplifier(SSPA).Based on the proposed predistorter and its balanced structure,five MMIC predistorter for 25?27 GHz and two MMIC predistorter for 37?42.5 GHz are designed using the 0.10 um Ga As process.The result of the test shows that the MMIC predistorter in the frequency range of 25?27 GHz has good predistortion performance and independent tunability,with the gain expansion is more than 5 d B,the phase compression can be flexibly adjusted,which can be changed by more than 30°;the MMIC predistorter in the frequency range of 37?42.5 GHz only show predistortion performance,with the gain expansion is more than 2 d B and the phase compression is more than 28°.The driver module with tunable gain of the analog predistortion linearizer is designed and implemented,and the MMIC predistorter cascaded solid-state power amplifier was tested with single-tone and two-tone in all frequency bands.The single-tone test results show that the predistorter improves the output P_{1d B} of the solid-state power amplifier by more than 2 d B in the frequency range of 25?27 GHz.The results of two-tone test show that in the frequency range of 25?27 GHz,when the output power is set back 3?7 d B from the 1 d B compression point,the improvement of the third-order intermodulation of the MMIC predistorter on the solid-state power amplifier is more than10 d B,and the maximum improvement is 15.62 d B;in the frequency range of 37?42.5GHz,when the output power is set back 2?3 d B from the 1 d B compression point,the MMIC predistorter improves the third-order intermodulation of the solid-state power amplifier by more than 6 d B,up to 14.64 d B.