Research Of Key Technologies Of Silicon-based Millimeter-wave Power Amplifiers For 5G Communications

With the high-speed development of the Mobile Internet,the fifth-generation mobile communication technology(5G)uses larger signal bandwidth and more complex modulation methods,then the data transmission speed is greatly increased which can satisfy people's demand.In millimeter wave wireless communication transceiver chip design,the power amplifier output power,linearity and power added efficiency determine the distance and quality of communication.This paper studies and designs silicon-based millimeter wave power amplifiers for 5G communications.The main contents include:Two 70GHz power amplifier chips PA1 and PA2 have been designed.PA1 uses single-channel differential cascode structure,the commom-source and commom-gate transistors'layout are optimized respectively.Using neutralization capacitor technology to eliminate the impact of feedback capacitor C_GD.Using common-gate-shorted technology to increase the maximum obtainable gain.Using inter-stage series and parallel inductors to improve power gain.PA2 uses two-channel power combining technology.Using a three-turn stacked power combiner with parallel inductors is innovatively proposed.Compared with the traditional power combiner structure,the insertion loss has been optimized.The optimal position of the power divider has been analyzed,which reduces the power consumption of the driver stage and improves the efficiency.According to the on-chip transformer pole theory,resonant peak controlling technology is proposed to control the two pole positions of the on-chip transformer,achieving a larger transimpedance in the working frequency band and improve the gain of the power amplifier.Chip measurement result:the peak gain of PA1 is 20.1d B at 67GHz,the 3d B bandwidth is 61.7-71.1GHz,the peak gain of PA2 is 26.0d B at 71.2GHz,the 3d B bandwidth is 67.4?74.6GHz.The input is 68GHz sine wave signal,the maximum output power,OP1d B,the maximum PAE of PA1 is 13.29d Bm,9.6d Bm and 10.5%,respectively.The input fundamental frequency is 70.5GHz sine wave signal,the maximum output power,OP1d B,the maximum PAE of PA1 is 14.08d Bm,11.3d Bm and 24.3%,respectively.A 28GHz power amplifier(PA3)for 5G communication has been designed,using Doherty technology to improve the efficiency of the back-off point,the input phase shift network and load modulation network are both designed with a highpass?-type network,and the number of passive devices is reduced for compact area by inductance combination.The adaptive bias technology increases the output power.Using MOS capacitor compensation technology improves linearity.Post simulation results:the peak gain of PA3 is 17.7d B at 27.1GHz,the 3d B bandwidth is 25.6?28.9GHz.The input is 28GHz sine wave signal,the maximum output power,OP1d B,the maximum PAE and the 6d B power back-off PAE of PA3 is19.8d Bm,18.8d Bm,20.5%and 10%,respectively.And the linear output power is within 18.8d Bm,while AM-PM distortion is less than 3°.After using 80MHz modulation signal bandwidth 64QAM modulation method,the average output power of the power amplifier is 13.5d Bm,the ACPR is approximately equal to-31.2dBc and the EVM is-24dB.