Degeneration for a Wideband Voltage-Controlled Oscillator

The present disclosure describes aspects of degeneration for a wideband voltage-controlled oscillator (VCO) circuit. In some aspects, the VCO circuit includes a degeneration network that includes a first inductor, a second inductor, and a capacitor. The degeneration network is connected between the a supply voltage and ground, with the capacitor connected across the differential VCO, between the sources of cross-coupled PMOS transistors and the sources of cross-coupled NMOS transistors. Control circuitry selects an inductance value of a switched inductance network to select a frequency band in which the VCO circuit operates. The control circuitry also sets a switched capacitor bank and a variable capacitor bank to tune the VCO circuit to an operating frequency within the selected frequency band. The control circuitry further tunes the degeneration network to degenerate the VCO circuit to reduce phase noise in an output signal of the VCO circuit.