Low frequency recursive digital differentiator

In this paper, modified Schneider operator and modified AL-SKG rule based recursive digital differentiators have been analyzed in the low frequency range. The first order s-to-z transformations obtained are in close conformity to the ideal differentiator in terms of magnitude. The phase response shows a linear variation in this range which is also desirable for several applications. MATLAB simulation results are presented to validate the effectiveness of the proposed analysis. These models can be used for discrete realizations of low frequency differentiators.