Research And Design Of CMOS Switch For Millimeter Wave Wireless Communication Applications

The evolution of modern wireless communication technology has brought new application scenarios to millimeter-wave wireless communication.How to design a high-integration and low-cost millimeter wave front-end circuit has become a research hotspot.Compared with the current mainstream semiconductor process,CMOS process has lower cost and higher integration,and has received extensive attention from industry and academia.Switches are widely used in millimeter-wave time division duplex phased array systems,and are important modules in wireless communication transceiver systems.Based on the 65-nm CMOS process,this thesis studies millimeter wave switch chips used in wireless communication systems.In the first place,this thesis introduced the research background and significance of this subject,and investigates the research history and development trends of switch chips at home and abroad.Then this thesis introduces the design basis of millimeter wave switch chip design.By using 65-nm CMOS technology,four single-pole double-throw chips were designed,focusing on optimizing the insertion loss,power handling capability and working bandwidth of the switch chip,and they were successfully taped out and tested.The first single-pole double-throw switch chip has a working frequency of 3.5GHz to 9GHz.Based on the traditional series-parallel structure,the traditional parallel single transistor is changed to a stacked parallel double transistor,which improves the linearity of the traditional series-parallel structure by 2d B.The post-simulation results show that the insertion loss including the connecting transmission line is less than 1.2d B,the isolation is greater than 30 d B,and the input1 d B compression point is 8.8d Bm.The second single-pole double-throw switch has a working frequency range of 16 GHz to 26 GHz and adopts a symmetrical structure.In order to solve the problem of bad isolation and excessive insertion loss of the series-parallel structure in the millimeter wave frequency band,an isolation inductor is introduced to optimize the insertion loss of the switch.The test result shows that the insertion loss is 2d B to 3.1d B,and the isolation is greater than 20 d B,with the input and output return loss of less than-8d B.The third single-pole double-throw switch has a working frequency range of 23 GHz to 31 GHz and adopts an asymmetric structure,focusing on optimizing the power handling capability of the single-pole double-throw switch transmission mode.The test result shows that the insertion loss of its launch state is 2.2d B to 3d B,while the isolation is greater than 20 d B,with its input 0.7d B compression point of 27 d Bm.Due to the particularity of the three-port device,the input and output echo parameters measured in the receiving state are less than-8d B.The last switch chip uses the additional inductors cooperating with the parasitic capacitance of the transistor to form a broadband matching network and extends the working bandwidth to DC to 50 GHz.The actual test frequency band is 15 GHz to 40 GHz,and the measured insertion loss is 1.8d B to 2.4d B with isolation larger than 24 d B.The measured input and output echo parameters are less than-13 d B with its input 1d B compression point of 10.5d Bm.The research on millimeter-wave switch chips in this subject verifies the possibility of achieving high linearity and ultra-wideband switches based on CMOS technology,and also provides ideas for domestic research on millimeter-wave switches.