A monolithic reduced-size Ku-band SPDT FET switch

A GaAs Ku-band monolithic single-pole double-throw (SPDT) FET switch has been designed and demonstrated. Small-signal insertion loss is less than 1.4 dB over a 14-GHz-to-18-GHz bandwidth with a VSWR (voltage standing-wave ratio) less than 1.5:1. The common terminal-to-off-channel isolation exceeds 18 dB. The switching is achieved with a -4.5-V signal on the gate of the on-channel FET with the other gate at 0 V. The switching current requirement is only the reverse bias gate leakage current (typically 3 mu A). Large-signal performance is similar with a -10-V control signal. The small chip size, 1.3 mm*1.3 mm*0.15 mm, permits more than 2300 monolithic switches to be fabricated on a single 3-in GaAs wafer.<>