First-order universal shadow filter designs with scaled time constants

Abstract

First-order generalized filter designs which simultaneously offer implementation of the low-pass, high-pass, and all-pass filters basic functions with scaling of the associated time constant are presented in this work. These have been achieved thanks to the employment of the shadow filtering technique, which enables the utilization of a hidden filter for performing scaling of the time constant. The resulting filters offer also a high-impedance input, and as the outputs are also taken from low-impedance nodes, there is not any imposed restriction concerning their cascadability. The provided simulation and experimental results confirm the validity of the proposed concept. First-order generalized filter designs which simultaneously offer implementation of the low-pass, high-pass, and all-pass filters basic functions with scaling of the associated time constant are presented in this work. These have been achieved thanks to the employment of the shadow filtering technique, which enables the utilization of a hidden filter for performing scaling of the time constant. image