Low-sensitive CCII-based biquadratic filters offering electronic frequencyshifting

Two novel filter implementations offering electronic frequency shifting are presented. In particular, the first implementation realizes the complete b iquadratic function, while the second gives simultaneously high-pass, low p ass, and bandpass second-order transfer functions. The filters are construc ted by CCII's, two of which have tunable current gain employed for frequenc y shifting. Moreover, we propose design procedures which keep most of the p assive and active sensitivities to low values, while diminishing the influe nce of the parasitic elements existing at the CCII terminals on filter freq uency response. The performance of the proposed filters and the effectivene ss of the design procedure in minimizing the parasitics effects were examin ed by PSPICE simulation.