A DC-to-8 GHz 60-dB Isolation SPDT Switch with Auxiliary Path Cancellation in 65-nm Bulk CMOS

This work presents a dc-to-8 GHz single-pole double-throw (SPDT) switch in 65-nm bulk CMOS technology. The auxiliary signal branch, inserted between the switches' two throws, comprises a set of grounded parallel-coupled inductors and their corresponding control transistors. Owing to its unique impedance properties, the switch maintains high isolation within its operating frequency band and optimize insertion loss simultaneously. The measurement results of the manufactured SPDT switch demonstrate an insertion loss of less than 1.3 dB and an isolation level exceeding 60 dB in dc-to-8 GHz, which achieves the best isolation in the corresponding frequency band. Furthermore, the measurement
$\mathbf{IP}_{1\mathbf{dB}}$
is 18.6 dBm at 5.2 GHz with negative gate bias.