Research On Active Phase Shifter Based On InP DHBT Technology

As a necessity in the daily life of the general public,the rapid development process of wireless communication system leads to the iteration of many technologies.At this time,the multi-task,multi-target and multi-function phased array technology has set off a research upsurge.With the advancement of phased array technology,the phase shifter which is the core device of phased array technology,has high precision,low phase error,large bandwidth and compact area as its constant development goals.InP materials have broad application prospects in radio frequency devices due to their superior highfrequency properties.The main research content of this thesis is to design a 6 bit active phase shifter based on the InP DHBT process.And this thesis provides a feasible implementation scheme to solve the problem that a single type of transistor cannot be applied to the classical active phase shifter architecture.The research content mainly includes the following points:1.An active tunable polyphase filter is designed in order to improve the performance of the quadrature signal generator in terms of bandwidth,phase error and insertion loss.Specifically,the resistance and capacitance in the traditional polyphase filter are replaced by the transconductance and junction capacitance of the transistor,and the center frequency of the two-stage circuit is changed by adjusting the bias voltage.The test results show that the operating frequency band can be extended to 10-35 GHz,the phase error is less than 10°,the gain error is less than 2 d B,and the return loss performance is good.2.This thesis proposes a vector synthesizer with quadrant switching,which is mainly composed of two Gilbert units with switches.The quadrant is selected by digital switches,and the amplitude-weighted quadrature differential signals are synthesized.Simulation result shows that the circuit can cover the 360° phase shift range and complete the switching of four quadrants.3.Research on a current-configurable amplitude control unit to solve the problem of amplitude weighting of single type transistors.Firstly,multiple current mirror arrays are built in the form of pull-up resistors to generate different proportions of I and Q channel currents based on the mirror current source structure.A current transfer scheme is studied to transfer the proportions of the two channels to the tail current source of the vector combiner and perform amplitude weighting to synthesize 64 phase states.4.Based on 0.7 ?m InP DHBT process for six bit active phase shifter layout design.The simulation results show that the active phase shifter can achieve six phase shift accuracy in the range of 18-26 GHz,RMS phase error < 1.4°,RMS gain error < 1.2 d B,circuit gain is 0?4.5 dB,and the chip area is only 1.22mm*1.01 mm.