Design of compact and wide bandwidth SPDT with anti-stiction torsional RF MEMS series capacitive switch

This paper presents a new single pole double throw (SPDT) RF MEMS switch design based on a torsional series capacitive switch. The torsional configuration and use of floating metal reduce the stiction probabilities. Use of a single series capacitive switch compared to the conventional approach of a capacitive and series combination, offers compact size, higher bandwidth and superior reliability. The optimized SPDT topology offers a wider bandwidth of 17 GHz (3-20 GHz) with insertion loss of -0.3 to -0.4 dB and isolation -20 to -44 dB. The proposed structure actuates at 9 V and the contact force varies in the elastic contact regime from 20 to 68 A mu N for the bias voltage of 10-15 V.