Analog realization of fractional filters: Laguerre approximation approach

Fractional filters are attractive tools for signal processing allowing greater flexibility in shaping the frequency response. Unfortunately they are very difficult to realize directly, as for digital approach they require infinite memory and for analog approach they require fully fractional capacitors or inductors. That is why approximation approaches are so attractive. In this paper we present a method of implementing an analog approximation of fractional filter. Our approach is based on Laguerre Impulse Response Approximation method. We present its modification allowing reduction of the required connections and without problems with signal-to-noise ratios. Our results are illustrated both with simulations and with experiments. (C) 2017 Elsevier GmbH. All rights reserved.