A scheme for the KHN state variable filter to improve its high frequency performance

Abstract

The state variable filter, also known as the KHN filter, is well known for its low sensitivities to the passive elements. However, its sensitivities to the finite gain bandwidth product of the operational amplifiers limit its performance for high frequencies. This modification consists in providing a positive feedback in the summing amplifier. Simulation of the proposed scheme and a comparison of the results with the conventional KHN filter is presented.