ABSTRACT
This chapter provides an overview of the basic principles associated with the analysis and design of digital filters. It describes the characterization of digital filters in terms of difference equations and their representation in terms of networks. The chapter also provides a brief comparison between analog and digital filters. It examines some key issues in filter design, namely, amplitude and phase distortion and the importance of a linear phase response. Frequency-domain analysis can be carried out by finding the steady state sinusoidal response as in analog filters and systems. Analog filters are characterized in terms of differential equations. Digital filters, on the other hand, are characterized in terms of difference equations. A digital filter, like an analog filter, can be represented in the frequency domain by its amplitude and phase responses which are the gain and phase shift of the filter as functions of frequency.
