A new pipelined architecture for allpass digital filters based on the 3-port adaptor

Allpass digital filters are major building blocks in many digital filter structures. A new pipelined architecture for the 2/sup nd/ order allpass section based on the 3-port series adaptor is presented. It is shown how to maximise the sample rate whilst applying the minimum level of pipelining. The new architecture has up to double the maximum sample rate of other structures.