Novel Voltage-Mode Structurely Allpass Filters Without External Passive Components

Abstract

In this work, two voltage-mode filters, a first-order and a second-order structurely allpass filter, realized with active components only, are presented. The circuits employ only operational transconductance amplifiers (OTA) and internally compensated operational amplifiers (OA). The second-order filter parameters are independently adjustable. Simulation results are included to verify theory