A Q-/V-band 37.6-dBm IP0.1 dB and low loss SPDT switch using three-series PIN diodes connection

This manuscript presents a novel three-series-only topology P-insulator-N (PIN) diode single-pole-double-through (SPDT) switch designed to address the challenges of high power handling and low insertion loss in Q-band and V-band communication systems. The manuscript provides a detailed theoretical analysis of series-connected PIN diodes, offering insights into their behavior under both small- and large-signal conditions. Based on GaAs PIN diode technology, the switch operates across a frequency range of 37.7 to 61 GHz, achieving a low insertion loss of 0.707 dB and providing an isolation of 24.6 dB. The proposed SPDT switch demonstrates a high IP0.1~dB of 37.6 dBm at 38 GHz. With a compact chip size of 0.905× 0.885 mm² , including all pads, this work offers excellent power handling capability, making it highly suitable for advanced communication systems in Q-band and V-band applications.