Switched-inductor VCO based on tapped vertical solenoid inductors

A new switched-inductor voltage controlled oscillator (VCO) scheme based on tapped vertical solenoid inductors is presented. With tapping ports, various effective inductances are selected by switches for multi-band operation. As a proof of concept, two VCOs, with one and two tapping ports separately, are implemented in a 0.18 m 1P6M standard CMOS. Because of the vertical structure of the inductors, the new scheme consumes much less area than the conventional switch-inductor VCOs. The measured frequency bands of the VCOs are located between 1.96 and 3.49 GHz, and the measured phase noise at 1 MHz offset is between 115.4 and 118.5 dBc/Hz across all bands under power consumption of 14.4 mW (8 mA, 1.8 V).