Abstract
A universal active biquad using the four-terminal floating nullors
(FTFNs) is presented. The propsed circuit uses two FTFNs,
three capacitors and two resistors. The proposed circuit has three
input voltages and can simultaneously provide a high-impedance
output current and/or an output voltage. Without changing the
circuit topology, the output voltage can realise lowpass,
highpass, bandpass, notch and allpass transfer functions and the
output current can realise bandpass and highpass transfer
functions. The proposed circuit enjoys low active and passive
sensitivities and independent control of the parameters