CFET-a new high quality MMIC control device

A new GaAs device developed for use in microwave monolithic control circuitry has been demonstrated. Known as a CFET, for Control Field Effect Transistor, this device eliminates the need for a conventional submicron gate by achieving control by use of a gate located behind the source-drain channel. The resulting capacitance is smaller than a conventional MESEET, resulting in a figure of merit of 800 GHz as compared to 250 GHz for a conventional MESFET. The device capabilities are demonstrated by measured performance of a SPDT switch providing 0.35-dB insertion loss and 20-dB isolation over the DC -10.0-GHz frequency band.<>