A switched capacitor time-division-multiplexed pole sharing technique for linear phase bandpass filterbanks

A switched-capacitor time-division-multiplexed pole sharing technique for implementing bandpass filter banks is proposed. Using this technique, the hardware reduction is achieved in three ways. First, the efficient non-minimum-phase Lerner filter approximation is used to minimize the number of poles required to satisfy a given filter specification in frequency and time domains. Second, the number of poles is reduced by pole sharing and third, hardware for implementation is simplified by time-division-multiplexing. In the case of the 8th-order-per-channel 16-channel bandpass filter bank example discussed, the total hardware reduction is substantially greater than 50% when compared to a conventional direct design using minimum-phase filter approximations. Furthermore, the proposed technique is parasitic-insensitive and compatible with micropower techniques.<>