Programmable Transversal Filters: Applications and Capabilities

Abstract

Transversal filters, which have found wide application in signal processing, consist of a delay medium and taps to replicate an input signal at various lags, and means for weighting and summing of these replicas to provide an output signal. The pattern of the tap weights constitutes a filtering function; a structure which enables this function to be changed readily is referred to as a programmable transversal filter. This paper will describe PTF parameters and attributes in light of various systems applications. Examples of parameters that must be considered when selecting a component are bandwidth, number of taps, dynamic range, accuracy, linearity, and programming rate. After discussing applications, various SAW approaches to implementing PTFs will be reviewed, as will alternate approaches.