A 325 GHz Quadrature Voltage Controlled Oscillator With Superharmonic-Coupling

We present a 325 GHz quadrature voltage controlled oscillator (QVCO) using 0.25 μm InP HBT technology and superharmonic coupling of two differential Colpitts VCOs. The individual VCOs exhibit about -5-dBm single-ended output power and 10 GHz frequency tuning range. The quadrature oscillation is successfully demonstrated with dc power consumption of 92.4 mW and phase imbalance less than ±12° at around 325 GHz.