Modeling and Performance Improvement of Fractional-Order Band-Pass Filter Using Fractional Elements

Fractional-order circuits are the emerging area for analyzing the parametric response of the filters and its performance improvement can be analytically observed by using an optimization technique. In this paper, the fractional-order band-pass filter, using fractional-order capacitor (FC) and fractional-order inductor (FI), is investigated. The characteristics of the filter with desired fractional-order of FC and FI bearing range from 0.1 <= alpha <= 1.0 to 0.1 <= beta <= 1.0, respectively having a step change of 0.1, are simulated. The frequency parameters of the proposed band-pass filter having order with in this range of alpha and beta resulted during simulation. The quality factor is optimized from the results of the fractional-orders alpha and beta for the given FC and FI, respectively. The theoretical quality factor in this integer-order filter is compared with its optimized Q value in its fractional-order counterpart. The proposed filter is modeled by using the best orders of alpha = 0.4 and beta = 1.0 for FC and FI, respectively with optimized Q-factor. Finally, the frequency parameters of the filter as modeled are obtained through simulation using MATLAB/Simulink R2011a.