COMPUTER-AIDED INTERACTIVE FILTER DESIGN USING TEMPLATES

Particular properties of symmetric lattices provide a convenient basis for the development of an empirical approach, based on templates, to the design of analog filters. These templates can be used for the design of filters with demanding specifications for attenuation and phase responses, and also for the design of equalisers. This paper presents an effective interactive computer tool as part of a computer-aided approach to this problem, and presents significant extensions to the theory to enable the designer to determine the transfer function by specifying the desired attenuation at a number of points. The design leads to reactance functions that define the arms of a symmetric lattice. The transfer function of the filter is also produced, and can be used to give other realisations.