High-Power Broadband GaN HEMT SPST/SPDT Switches Based on Resonance Inductors and Shunt-Stacked Transistors

Novel X-band high-power monolithic SPST/SPDT switches in coplanar GaN technology are presented. The SPDT switch exhibits 1.6 dB on-state insertion loss and better than 20 dB isolation. Power handling measurements have shown that the 1 dB compression point occurs with an input power equal to 38 dBm at 10 GHz. A combination of techniques were used to yield higher power handling while preserving low loss and high isolation. These circuit techniques include the use of stacked HEMTs to improve power handling and to minimize the loss and maintain high isolation, and also the use of a resonance inductor in parallel with the series HEMTs to improve the isolation of the switch. Simulated and experimental results are presented in support of the novel switches.