50-110 GHz, high isolation, and high-power linearity single-pole double-throw switch utilizing 100-nm GaN HEMT technology

This article presents the design and performance of a single-pole double-throw(SPDT) switch operating in 50-110 GHz. The switch is fabricated in a 100-nm GaN high-electron-mobility transistors(HEMT) technology. To realize high-power capability, the dimensions of GaN HEMTs are selected by simulation verification. To enhance the isolation, an improved structure of shunt HEMT with two ground holes is employed. To extend the operation bandwidth, the SPDT switch with multi-section resonant units is proposed and analyzed. To verify the SPDT switch design, a prototype operating in 50-110 GHz is fabricated. The measured results show that the fabricated SPDT switch monolithic microwave integrated circuit(MMIC) achieves an input 1 dB compression point(P1dB) of 38 dBm at 94 GHz, and isolation within the range of 33 dB to 54 dB in 50-110 GHz. The insertion loss of the switch is less than 2.1 dB, while the voltage standing wave ratios(VSWR) of the input port and output port are both less than 1.8 in the operation bandwidth. Based on the measured results, the presented SPDT switch MMIC demonstrates high power capability and high isolation compared with other reported millimeter-wave SPDT MMIC designs.