An Electronically Tunable Universal Non-Integer-Order Filter Structure

A re-configurable structure capable of implementing all the elementary non-integer-order filter functions and, also, the associated inverse filter functions, is introduced in this work. This is achieved through the utilization of a curve-fitting based approximation technique, which allows the approximation of the filter functions through integer-order transfer functions of the same form. The employment of Operational Transconductance Amplifiers as active elements offers electronic adjustment of the realized time constants and scaling factors. The provided simulation results confirm the validity of the presented concept.