Tapped integrated inductors: Modelling and Application in Multi-Band RF Circuits

As CMOS scales down and sees is cost per mm2 increasing, area-aware RF design solutions are called for. Integrated inductors with multiple taps allow for low-area multi-band RF circuit design. This work reports on the design of these inductors and provides modelling and extraction procedures demonstrated on 4-port measurements. Additionally, the application of such inductors is demonstrated on a low-area switchable dual-band VCO in 90 nm CMOS with an area of only 0.04 mm2. Dual-band operation around 3.5 and 10 GHz is achieved, with a high FOM of 182 dB. This performance demonstrates the opportunities using tapped inductors for high-performance area-aware RF design.