DIGITAL DOMAIN DESIGN OF CASCADED LADDER WAVE DIGITAL FILTERS WITH TUNABLE PARAMETERS
Salina Abdul Samad · Iranian journal of electrical and computer engineering · 2004
A digital domain design of cascaded ladder WDFs using simple design parameters is presented. This special class of filters uses first order sections that are cascaded to realize N-order lowpass or highpass filters with tunable 3-dB cut-off frequency. To obtain the design parameters, the correspondence between the adaptor coefficient and the digital domain transfer function is shown. The transfer function is then used to derive the equations for the tunable coefficients in terms of the required cut-off frequency and filter order. The resulting structures are highly modular requiring the same type of adaptor throughout the structure. In addition, the number of coefficients required is minimal and is equal to the order of the filter.