W-BAND SPST TRANSISTOR SWITCHES

A single-pole, single-throw (SPST) transistor switch has been develope d, Three types of switches, that is, GaAs MESFET, AlGaAs/GaAs HEMT, an d pseudomorphic HEMT (PM-HEMT), have been fabricated, and the performa nces at W-band are compared. To reduce on-state resistance and off-sta te capacitance, a gate length was varied as a parameter, Moreover, an inductance for resonance was installed in parallel to the off-state ca pacitance between source and drain to obtain a high isolation, A relat ively low insertion loss of 1.6 dB and a high isolation over 20 dB at W-band have been obtained from the 0.8-mu m gate length PM-HEMT.