Design of Active Inductor and Stability Test for Ladder RLC Low-pass Filter Based on Widened Superposition and Voltage Injection

Abstract

A design of ladder RLC low pass filter is presented. The loop gain of this filter is derived and analyzed based on the widened superposition principle. The voltage injection technique is used to measure this loop gain. An active inductor is designed using a general impedance converter. In the paper not only the results of the optimization but also the results of simulation of the designed circuits are provided, including the stability test. Research results show that this filter may cause the damped oscillation noise when the stable conditions are not satisfied.