Design of fractional notch filter with asymmetric slopes and large values of notch magnitude

In this paper, we propose a 2^nd order fractional band reject filter (FBRF) transfer function. It is based on the concept of introducing a fractional capacitor (C_α) having impedance, Z_α = 1 over s^αC_α where 0 <; α <; 1. It is possible to achieve asymmetric slopes and large values of notch magnitude up to -60 dB using this filter. In addition, unlike integer order filter, independent control of slopes above and below the notch frequency can be achieved by simply changing the values of α. The operation of this filter is verified by plotting PSPICE simulation results for three different values of α = 0.1; 0.5; 0.8 and showing its comparison with experimental results.