DC-50 GHz small-size HJFET MMIC switch for high power applications

This paper describes a very small size SPST (single pole single throw) MMIC switch, in which a novel ohmic electrode sharing technology (OEST) has been employed. OEST reduces MMIC chip size by arraying FETs without intentionally wiring the series FET with the shunt FET. The developed SPST switch, excluding bonding pads, has achieved very small size of 0.17 mm × 0.07 mm, which is as small as a single-FET pattern with four gate fingers. Small-signal characterization exhibits excellent switching performance, including ON/OFF ratio of better than 20 dB from dc to 50 GHz. The increase in the insertion loss with increasing the input power is less than 1 dB up to an input power of 20.55 dBm at 40 GHz. The ON/OFF ratio is better than 20 dB up to an input power of 17.55 dBm, indicating excellent power handling capability at millimeter-wave frequencies.