Design approach for tunable CMOS active inductor

A design approach for differential CMOS active inductor with a self-resonant frequency around 1.58GHz-3.98GHz is presented. The architecture is based on a differential gyrator-C topology to transform intrinsic capacitance of a MOSFET to the emulated inductance. Due to high power consumption of active inductor, only a current source is used. This design has the capability to tune the inductor and Q-factor values from 10nH-60nH and 20-60 respectively. Furthermore, a technique is proposed to ensure smaller inductance value can be achieved with smaller power consumption and die area.