High input impedance current controlled voltage-mode universal filter using DDCC and OTA

This article presents a voltage-mode universal biquadratic filter performing simultaneous 3 standard functions: low-pass, high-pass and band-pass functions, employing differential different current conveyor (DDCC) and operational transconductance amplifier (OTA) as active element. The features of the circuit are that: the quality factor and pole frequency can be tuned electronically via the input bias currents: the circuit description is very simple, consisting of 1 DDCC, 1 OTA, 1 electronic resistor and 2 grounded capacitors. Without requiring component matching conditions, the proposed circuit is very appropriate to further develop into an integrated circuit. The PSPICE simulation results are depicted. The given results agree well with the theoretical anticipation.