Design Of A DC?6GHz SOI CMOS Single-Pole Double-Throw RF Switch

The rapid development of mobile communication technology promotes mobile terminal devices to become more and more intelligent.RF switches used in mobile terminal devices play an important role in the design of RF front-end.Mobile terminal devices such as smartphones and tablets support wireless communication services in multiple frequency bands and multiple modes through integrating RF switches in the RF front-end,while providing the functions of global positioning system,wireless local area network,bluetooth communication,radio frequency identification and so on,which brings great convenience to people's life.With the age of 5G communication coming,as an important component of the RF front-end of a wireless communication module,a radio frequency switch has higher requirements on the performance of linearity,insertion loss,and isolation.This DC?6GHz single-pole double-throw RF switch uses 0.28?m SOI CMOS process to complete the design.The single-pole double-throw RF switch integrates a switch drive module and a switch core circuit module.The switch drive module is used for generating a stable negative voltage.The switch drive module includes an oscillator,a clock buffer circuit,a negative voltage charge pump and a level conversion circuit.The switch core circuit adopts a series-parallel structure,which has high isolation and low insertion loss.Based on adopting a series-parallel structure,the RF switch circuit uses floating-gate technology,transistor stacking technology and negative voltage bias technology to improve the power handling capability and insertion loss performance of the switch.When the switch turns off,the gate and body terminals of the switching transistor use negative voltage bias to reduces the equivalent switch-off capacitance of the switch and enhances the power processing capabilities and improves isolation performance.The post-simulation results in the Cadence Spectre environment show that under the 2.5V power supply voltage,in the frequency range of DC to 6GHz,the insertion loss of single-pole double-throw RF switches is less than 1d B,the isolation is greater than 27 d B,the input 1d B compression point is greater than 28 d Bm,the switching time is less than 1 ?s.The overall layout size of the single-pole double-throw RF switch is 0.67 mm × 0.41 mm.The performance of the DC?6GHz single-pole double-throw RF switch all meets the design specification.After the verification of the tape,it can be used in chips such as WLAN connection,RFID and FM radio in smart phones,and it can also be used in the broadband power amplifier system integrating band selector switch.