New Multi-function Third-Order Inverse Filter using OTRAs

The inverse filters are commonly used in the fields of signal processing, communication, instrumentation, and control system for the recovery of a distorted signal. In this paper, an operational transresistance amplifier (OTRA)-based third-order multi-function inverse filter has been proposed. The proposed method uses two OTRAs and suitable combinations of admittances to realize the frequency response characteristics of inverse low-pass filter, inverse band-pass filter, inverse high-pass filter, and inverse band-reject filter. The proposed circuits have been verified by PSPICE simulations with the CMOS model of OTRA using 0.5 μm CMOS technology. The proposed third-order multi-function inverse filters give a frequency roll-off in the range of 49.79 dB/decade to 55.38 dB/decade in the transition band which gives an improvement of almost 25 to 38% in roll-off in comparison with the existing literature. The experimental verification of the proposed structure is also included. © 2021, The Institution of Engineers (India).