CMOS floating active inductor and its applications to bandpass filter and oscillator designs

A CMOS fully differential floating active inductor is realised by exploitin g the intrinsic capacitance of the transistor. This technique allows the si mulated inductor to operate closer to the f(T) of the technology. Simulatio n results using SpectreRF with AMS 0.8 mu m CMOS process show a self-resona nt frequency over 1GHz, and independent tuning of the inductance and the se ries resistance values. The floating active inductor has been employed in t he design of a fourth-order 100MHz IF bandpass filter and a second-order RF tunable oscillator to demonstrate its performance.