Tunable Multifunction Filter Using Current Conveyor

TL;DR

This paper introduces a current conveyor-based tunable multifunction filter capable of functioning as low pass, high pass, band pass, or elliptical notch filter, with on-chip tunability and no component matching requirements.

Contribution

It presents a novel circuit design employing current conveyors and OTA for a tunable multifunction filter with orthogonal tuning of resonance frequency and bandwidth.

Findings

Successful simulation with HSPICE verifies theoretical results.

The filter's cutoff frequency is tunable via bias current adjustment.

The circuit is suitable for integration due to its simple grounded components.

Abstract

The paper presents a current tunable multifunction filter using current conveyor. The proposed circuit can be realized as on chip tunable low pass, high pass, band pass and elliptical notch filter. The circuit employs two current conveyors, one OTA, four resistors and two grounded capacitors, ideal for integration. It has only one output terminal and the number of input terminals may be used. Further, there is no requirement for component matching in the circuit. The resonance frequency ({\omega}0) and bandwidth ({\omega}0 /Q) enjoy orthogonal tuning. The cutoff frequency of the filter is tunable by changing the bias current, which makes it on chip tunable filter. The circuit is realized by using commercially available current conveyor AD844 and OTA LM13700. A HSPICE simulation of circuit is also studied for the verification of theoretical results.