Research And Manufacture Of Wideband RF Phase Shifter

With the development of wireless communication technology,phased array technology has made significant breakthroughs in improving phase shifting accuracy and bandwidth,and has been widely used in mobile communication(5G),satellite communication,and information sensing and fusion systems.The phase shifter can provide the required phase shift for the signal path of the phased array system,and is one of the core circuits of the phased array system.In recent years,domestically produced GaAs technology has gradually matured and has been widely used in domestically produced alternative products such as RF/microwave integrated circuits,greatly promoting the research of phase shifters based on Ga As technology.Small size,high phase shifting accuracy,and wideband phase shifters are currently a research hotspot.Based on domestically produced Ga As production technology,this paper conducts a series of research on RF phase shifters and their applications,with the following main work and contributions:1、Research on the bandwidth and phase shifting accuracy of phase shifters was carried out,and two 6-bit phase shifters working in the C/Ku band were proposed.The main structure of the phase shifter is completed by cascading 6-bit phase shift units,using high-pass and low-pass structures to achieve 180°,90°,and 45°phase shifts,T-type structures to achieve 22.5°phase shift,and series FET structures to achieve 11.25°and 5.625°phase shifts.The cascading order was optimized to achieve a phase shift range of 360°.Both phase shifters are fabricated based on domestically produced 0.5um Ga As technology.The measurement results show that the Ku band phase shifter has an insertion loss of 11.5d B,RMS phase error of 7.5°,good input-output return loss,and a chip area of 1.58*3.44mm~2;the C band phase shifter has an insertion loss of 8.5d B,RMS phase error of 4.5°,and a chip area of 1.58*4.84mm~2.2、To address the problem of phase accuracy difference within the bandwidth of the reflective phase shifter structure,a method of coupling the parallel capacitor to the ground at the same direction end of the coupler and controlling the reflection load with two-stage switch capacitors was proposed to improve phase balance and flatness.This method was applied to the reflective phase shifter structure to design a 6-bit phase shifter for 8-18GHz.The circuit was designed using 0.15um Ga As technology,and the simulation results showed that the insertion loss was-14.5d B,return loss was-10d B,and phase shifting accuracy was 6°within the 8-18GHz frequency range.The effectiveness of the proposed method for improving phase flatness within the wideband operating frequency range was verified.3、Combined with the developed C-band phase shifter,a domestically produced wafer-level packaging technology was used for the first time to design an impedance tuner.The impedance tuner integrates phase shifters,attenuators,and couplers to achieve input impedance tuning.The simulation results showed that the impedance tuner can generate impedance points with a VSWR of less than 1.7,and can be used for load pull testing of power amplifiers.