Wide tuning range W-band Colpitts VCO in 90nm CMOS

A compact wide tuning range design of a CMOS voltage-controlled oscillator (VCO) at W-band frequencies is presented. The design employs a differential Colpitts configuration, using a bufferless transformer output and nested inductors. The gate bias is used for frequency tuning that achieves a wide range of 93.7-100.7GHz. A peak output power of 4.7dBm with power efficiency of 5.5 is achieved at 98.8GHz and the phase noise is around -80dBc/Hz at 1MHz offset across the tuning range. The VCO uses a silicon area of 0.15mm ² including pads and, depending on bias, consumes between 6-63mW of DC power.