Design Algorithm for Multichannel Interleave Filters

A one-input M-output (1timesM) circuit configuration and design algorithm for an interleave filter with M output ports (Mges2) are presented. The circuit configuration is composed of a 1timesM optical lattice filter with a delay time of MDeltatau (Deltatau: unit delay time), an MtimesM diagonal delay matrix circuit, and an MtimesM modified inverse discrete Fourier transform matrix circuit. The proposed circuit with M=2 corresponds to a conventional interleave filter. The proposed synthesis algorithm is based on polyphase decomposition and yields circuit parameters ensuring that every output characteristic has an Mth-band property. A five-channel interleave filter is presented as an example of the design procedure.