A 24‐GHz active SPST MMIC switch with INGAP/GAAS HBTS

A 24‐GHz single‐pole, single‐throw (SPST) switch with high isolation is designed using InGaP/GaAs HBT process. To obtain high isolation in an off state, cascode structures are utilized and an additional shunt transistor is introduced in an output, which helps to reject a leakage signal. Dummy cascode structure is used as a current steering circuit for input matching and short rise/fall time. The fabricated SPST switch shows an effective isolation of ∼52 dB at 22.8 GHz and 41 dB at 24 GHz.