Current-mode CCII-based biquadratic filters offering electronic frequency shifting

Two novel filter implementations offering electronic frequency shifting are presented in this work. In particular, the first implementation realizes the complete biquadratic function while the second simulates high-pass, low-pass and band-pass second order transfer functions. The filters are constructed by CCIIs with unity current gain and utilize a minimum number of CCIIs with tunable current gain. A way leading to low sensitivity of specific parameters is proposed so that low sensitive filter design can be achieved. The circuits were tested using PSPICE simulation and proved to be of practical interest