Abstract

The development of MESFET MMIC switches for 28 GHz communication systems is presented. Transistors with different channel parameters and gate geometries have been developed and characterized in a SPST series switch configuration. The equivalent circuit parameters are determined by fitting the measured S parameters in the ON and OFF states. A cutoff frequency figure of merit up to 500 GHz is obtained depending on the transistor parameters. Several 28 GHz SPDT switches have been designed and fabricated. Typical input return loss better than 15 dB combined with 3 dB insertion loss and 22 dB isolation has been achieved.