High performance 77 GHz Single Pole Triple Throw (SP3T) MEMS switch

The design of a MEMS continuous ground Single-Pole-Triple-Throw (SP3T) switch that forms an integral part of a MEMS based radar working in the 77 GHz range has been presented. The SP3T RF MEMS switch incorporates 1 input port and 3 output ports. The design is based on electrostatically actuated cantilever beams and unlike other designs, uses a continuous ground that eliminate the effects of coupling capacitance between the ports and the ground. The HFSS simulation results show that at 77 GHz, the switch exhibits a return loss of better than 22 dB, insertion loss of 0.65 dB and an isolation of 15 dB among the ON and OFF ports. The switch is to be used for rapid switching of oscillator signals among the beam ports of a MEMS Rotman lens to realize a highly directional beam for position and proximity determination of vehicles or obstacles in an automotive collision avoidance system.