Research And Design Of Microwave Switch Chip

With the continuous development of wireless communication technology,modern microwave system needs to meet higher requirements for cost and integration.It has been a hot research that all modules of microwave transceiver system are integrated on a silicon substrate with CMOS technology at home and abroad.At present,due to high-power-handling-capability microwave power amplifier and switch,it is difficulty in realizing full integration for microwave front-end implementation.This thesis mainly conducts research on silicon-based CMOS microwave switch,driving the development of microwave system.In this paper,the key performance parameters of the microwave switch are studied in detail.The models and mechanisms of the important passive components are also described and studied to guide the design of high-quality passive components.Due to substrate conductivity and parasitic capacitors of triple-well bulk CMOS process,high-frequency low-insertion-loss switch is designed,based on equivalent lumped transmission-line structure,to reduce leakage loss of transistors.High-frequency high-isolation switch is realized by cascading structure on the basis of the low-insertion-loss microwave switch,which deteriorates insertion loss and improves isolation.Cascading transistors and feed-forward capacitors are used to increase power handling capability.High resistivity of SOI substrate is used to decrease substrate coupling effect due to buried oxide layer.The FB SOI NMOSFET is used to design low-frequency microwave switch with series-parallel structure,whose stacking transistors can effectively improve power handling capability.The wirebond package is also considered,simulated and designed with switch together,to reduce the impact on microwave performance of switch.According to measurement of high-frequency low-insertion-loss switch,at 16 GHz,the switch exhibits measured insertion loss of 4.3dB and 4.1dB,isolation of 26 dB and 24 dB,P0.1dB of 8dBm,and P1 dB of 13.5dBm,in Tx and Rx mode respectively.At 17.5GHz,high-frequency high-isolation switch achieves insertion loss of 2.7d B and 2.3dB,isolation of 42 dB and 31 dB,P1d B of 22 dBm,P0.1dB of 17 dBm,in different operating mode.For low-frequency high-power-handling-capability switch,the post-simulation results show insertion loss of less than 1.1dB,isolation of greater than 23 dB,return loss of greater than 10 dB,P1dB of about 44 dBm,and P0.1dB of about 41 dBm.The developed CMOS switch is basically in line with the expectation of performance requirements,and has reference to pushing development of full integration of microwave system with silicon-based CMOS technology.