Research On Key Technology Of Microwave And Millimeter-Wave Power Linearization And Power Driving

Power amplifier is a key component in wireless communication system.Solid state power amplifier(SSPA)and traveling wave tube amplifier(TWTA)are two commonly used power amplifiers in microwave and millimeter wave band.Their power,gain and linearity determine the performance of the whole communication system.Generally,power amplifier will work in the saturation region to achieve high efficiency,but now the nonlinearity is significantly improved.In order to improve the linearity and ensure the efficiency,power amplifier linearization technology has been proposed.The gain of power amplifier will fluctuate with the change of operating frequency,especially the gain of traveling wave tube amplifier has great unflatness,which seriously affects its output power and efficiency.The research of power driving technology is to provide driving power for traveling wave tube amplifier and solve the problem of uneven gain through the design of solid state power amplifier and gain equalizer,which is an important part of microwave millimeter Wave power module(MPM/MMPM).Based on the above background,this thesis studies the microwave millimeter wave power linearization technology and the key technologies of power drive in the microwave millimeter wave module.The main contents are as follows:1.Based on the analysis of the distortion causes and characteristics of power amplifier,the principle and design method of analog predistortion linearization technology are studied,and a new reconfigurable two-channel linearizer is designed and completed in W band.The nonlinear branch is designed by Schottky barrier diode,and the linear branch is designed by an amplitude and phase control chip.The gain and phase of the linearizer are highly flexible and adjustable,and the phase can be compressed or expanded from 10° to 60°.The amplitude can be adjusted by 2dB-10 dB.The proposed method can reconstruct both SSPA and TWTA predistortion curves in one circuit,and can also improve the amplitude unflatness problem of traditional wideband predistortion linearizers.2.Based on 0.15 um GaAs process,two MMIC linearizers operating at 6-18 GHz and 18-40 GHz,respectively,are designed.The gain expansion is more than 10 dB and the phase compression is more than 20°.Using the two chips as nonlinear branches and combined with the gain and phase control chip,two new two-channel linearizers are designed,which further verifies the structure of the new reconfigurable two-channel linearizers proposed in the previous section.3.After analyzing the key technologies of power drive in millimeter Wave Power Module(MMPM),a power drive module working in W band is developed for the traveling wave tube amplifier.The solid state power module can support pulse and continuous wave operation.The key factors affecting its gain equalization ability are studied.The final equalizer is more than 9dB and the return loss is better than 15 dB.Finally,the whole power drive module is processed and tested.