High-speed narrow-band lattice wave digital filters

A novel realization technique for high-speed narrow-band recursive filters is introduced. The realizations consist of a model filter and a number of masking filters in cascade. In the final realizations, all filters have a number of delay elements in their critical loops, resulting in a high maximal sample frequency. If a lattice WDF is used for the model filter, and bireciprocal lattice WDFs are used for the masking filters, then all the filters in a specific realization have about the same maximal sample frequency. An example is given which shows the advantage of the proposed realization, in terms of speed compared with the corresponding single-stage realization, and in terms of workload compared with the use of nonrecursive masking filters