Research On Chip Technology Of Terahertz Single-segment Multi-channel Phase Control Chip

Terahertz phase shifters are essential in wireless communication,radar application,and high-resolution imaging systems.However,the development of existing terahertz phase shifters has lagged,restricting the growth of terahertz-related application technologies.Given the development needs of application technology,this thesis designs two different types of 90° and 180° multi-bit phase shifters in the 220 GHz and340GHz frequency bands based on the rectangular waveguide transmission line.The device’s performance is verified through simulation optimization,fabrication and assembly,and related experimental tests.The main research work and results of this thesis are as follows:1.A waveguide-inserted single-segment terahertz multi-bit phase shifter structure is proposed,and the performance of the phase shifter is simulated and studied by combining field and circuit.The simulation results show that the 22.5° basic phase-shifting unit composed of diodes and phase-shifting microstructures meets the basic requirements of a multi-bit phase shifter.The multi-bit phase shifter with a center frequency of 220 GHz has four channels within a bandwidth of 5 GHz.The maximum phase shift of the 90° multi-phase shifter is 87.4°,and the maximum insertion loss is4 d B;the maximum phase shift of the 8-channel 180° multi-bit phase shifter is 185.6°,the maximum insertion loss is 8.2d B,and all have good phase shift Linearity.2.The experimental research and structural optimization of the waveguide-inserted single-segment multi-bit terahertz phase shifter have been completed.Compared with the simulation results,the initial measurement results show that the center frequency offset is large,and the insertion loss is too high.The main reasons are the deviation of the parameters of the substrate material and the mismatch of the impedance of the phase-shifting unit,which leads to excessive reflection.Increasing the parallel open-circuit branch in the basic phase-shifting unit is proposed to improve the impedance matching degree and optimize the structural parameters.The experimental results of the optimized 8-channel 180° multi-bit phase shifter show that in the frequency band of 219GHz～223GHz,the minimum insertion loss decreases by 6.22 d B,and the maximum phase shift reaches 187°.The experimental results and simulation results of the optimized phase-shift device are basically the same.Consistent.The preliminary research on the waveguide plug-in 180° multi-bit phase shifter was completed at 340 GHz.The experimental test results show that the center frequency of the device is shifted to high frequency by 5GHz.In the frequency band of342GHz～348GHz,the minimum insertion loss is 18.9d B,and the maximum phase shift is 104.6°.The diode parameters employed in the simulation design of the simulation result are deviated from the actual situation.3.The proposed terahertz reflection phase shifter structure is based on waveguide coupling.The simulation results indicate that the operating bandwidth of the device reaches 10GHz;By adjusting the operating voltage of the diode,the maximum phase shift in the 220 GHz frequency band gets 195.4°,and the in-band insertion loss is less than 6.4d B.In the 340 GHz single-die diode structure,the maximum phase shift angle188°,the intra-band insertion loss is less than 9.5d B.The reflection coefficient of the dual-die diode structure is significantly reduced near the center frequency of 340 GHz,and the maximum phase shift degree in the frequency band increases to 206°.