A Novel Multifunction CFOA-Based Inverse Filter

We present a novel multifunction inverse biquad configuration based on current feedback operational amplifiers (CFOAs) and grounded passive elements. The proposed scheme can be used to realize inverse lowpass, inverse bandpass and inverse highpass filter functions. The relevant coefficients of the inverse filters are orthogonal adjustable by independent passive elements. All the passive elements in the proposed scheme are grounded to benefit easier electronic tunability. With the high input impedance and low output impedance properties, the scheme is input and output cascadable for voltage operation. The feasibility of the proposed scheme is demonstrated by HSPICE simulations.