Alternate State Space Realization of Biquadratic Voltage Transfer Function Using Grounded Capacitors

Abstract

A state variable approach is proposed for the realization of a biquadratic voltage transfer function. It uses equal valued earthed capacitors. The first order all pass filter used as an elemental block in this circuit is shown to have a superior performance than Deboo's integrator. Subsequent analysis takes into account finite gain and finite bandwidth of the practical operational amplifiers used. Experimental results are presented for a bandpass filter that covers a wide range of Q factor and resonant frequency values. They agree well with the computed values obtained using numerical techniques.