Design of high order LPF with on chip active inductor using 0.18 micron CMOS technology

Active inductor is a circuit technique which is based on gyrator loop. Gyrator loop is composed of at least two transconductance amplifiers. Usually, the frequency response of active inductor has a phase shift 90 degrees at the resonance frequency. This paper proposes circuit technique which is based on complementary common source amplifier with drain degeneration resistors. The core circuit is connected by four transcondutors to form floating active inductor. Elements substitution is used to implement 5^th and 10^th order LPF Elliptic based on the proposed circuit. Due to nonlinear of a polynomial in the input impedance of transfer function, the inductor value is not constant as a function of input frequency. As a result, simulation results by Cadence Spectre is designed with transconductance curve compared with the graph of ideal LCR prototype by using 0.18 micron CMOS process.