Abstract: A 0～5GHz single-pole double-throw (SPDT) switching circuit using lateral metal-contacting MEMS switches is demonstrated. The MEMS switch consists of a set of quasi-finite ground coplanar waveguide (FGCPW) transmission lines and a right and left swing cantilever beam. A folded cantilever beam is proposed to reduce the driving voltage,and the structure is proven by theoretical analysis and simulation. The switches were successfully fabricated using the MetalMUMP process.At 5GHz,the measured insertion loss of the SPDT switching circuit is below 0.8dB,the return loss is higher than 20dB,and the isolation is as high as 40dB. The smallest pull-in voltage of the switches is 33V.

Key words: single-pole double-throw, RF MEMS, folded cantilever beam, lateral contact