High Isolation RF MEMS SPDT Switch for 60 GHz ISM Band Antenna Routing Applications

This work presents a two element antenna array using radio frequency microelectromechanical system (RF MEMS) based high isolation single-pole-double-throw (SPDT) switch at 60 GHz ISM band. The device is fabricated on 635 mu m alumina substrate using surface micromachining process. SPDT switch features a measured return loss of > 15 dB, insertion loss of < 2.8 dB and isolation of > 24.6 dB over the frequency band of 55- 65 GHz. Total area of the SPDT switch is 2.12 mm(2). To accomplish beam switching for routing applications, two patch antenna elements are monolithically integrated with the MEMS SPDT switch. Fabricated switched beam antenna exhibits a measured return loss of > 25 dB, and 10 dB impedance bandwidth of 4.2 % at 60 GHz with 66 V of bias voltage. Total area of the device is similar to 25 mm(2).