Current-mode universal biquadratic filter with single input and four outputs using FTFNs

Abstract

A novel four terminal floating nullor (FTFN) based universal current-mode (CM) biquadratic filter configuration with single input and four outputs (SIFO) is presented<b style="">. </b>The circuit is based on and employs six FTFNs of the same polarity and as many passive components and realizes simultaneously lowpass (LP), highpass (HP), inverted bandpass (BP) and Notch filtering functions without any imposition of component matching conditions or cancellation constraints. The circuit can also be made to realize allpass (AP) response by tying together appropriate output filtering signals. The topology has the distinct feature of low input and high output impedances which permits easy cascading for the construction of higher order filters. The circuit enjoys low passive sensitivity figures. The resonance frequency ω_oand bandwidth ω_o/Q can be independently tuned while as resonance frequency ω_oandquality factor Q can be orthogonally adjusted. Experimental and PSPICE simulation results are given to confirm the theoretical results.<b style=""> </b>