Improved quality-factor of 0.18-μm CMOS active inductor by a feedback resistance design

A novel CMOS active inductor approach, which can improve the quality-factor, was presented in this report. A cascode-grounded active inductor circuit topology with a feedback resistance was proposed, which can substantially improve its equivalent inductance and quality-factor. This feedback resistance active inductor was implemented by using a 0.18-μm 1P6M CMOS technology, which demonstrates a maximum quality-factor of 70 with a 5.7-nH inductance at 1.55 GHz, where the self-resonant frequency is 2.5 GHz. The dc power consumption of this active inductor is less than 8 mW.