Third Order Sallen key Lowpass Filter in Fractional Domain

摘要

This work introduces a Sallen key third order Lowpass filter in the fractional domain. The impact of fractional order capacitor (FOC) on the frequency response is presented. Present work uses three FOCs of same order. MATLAB and PSPICE simulations of the fractional lowpass filter of order 1.8, 2.4 and 3 are presented. For PSPICE simulations the FOCs are realized by Fourth-order approximation ladder network using continued fraction expansion method. Presented simulation results prove that the fractional order filter performs better as compared to integer order due to extra degree of freedom.