W-band GaAs PIN diode SPST switch MMIC

The design, fabrication, and experimental characteristics of GaAs PIN diodes are presented for W band monolithic integrated switches. The diodes with 20mm-diameter were used and showed a turn on voltage of 1.32 V, and a switching cutoff frequency of 4.0 THz. The monolithic integrated switches employed microstrip transmission lines and backside via holes for low-inductance signal grounding. A radial stub-based design was used for on-chip biasing, and the high-frequency characteristics of the switches were verified by on-wafer W-band testing. The SPST PIN monolithic switch demonstrated a low minimum insertion loss of 1.1 dB at 92 GHz and 30 dB isolation, 1.8 dB insertion loss in the frequency band from 85 GHz to 95 GHz.