Stability Analysis of Fractional-Order Filters Realized with PMMA Coated Elements

The initial work in this paper discusses the concept of stability of a circuit by transforming s-plane to F-plane and W-plane. This article also describes an approach to realize fractional-order active filters using fractional-order elements and studied its output voltage stability over a frequency range. The filters' response in both low and high frequency range have been simulated in P-Spice and Matlab for comparison with experimental results. Both low-pass and high-pass filters incorporate two capacitors which are used as non-integer (i.e. fractional) devices. This requires two fractional capacitors with orders $\alpha$ and $\beta(0 < \alpha,\ \beta\leq 1)$. The outputs of the two proposed filters shown in frequency domain were obtained experimentally and have been compared with simulated results using MATLAB and P-Spice toolbox. This simulation was carried out by taking fractional-order element which is approximated with a Domino Ladder network representation.