A pole sharing technique for linear phase switched-capacitor filter banks

摘要

A pole-sharing technique was used for implementing bandpass filter banks using the nonminimum-phase Lerner approximation without placing additional speed requirements on the operational amplifiers and without resorting to complicated clocking strategies; only a biphasic clock was used. Substantial hardware saving has been achieved. The filter synthesis is shown to be micropower-compatible and parasitic-insensitive; phase reversal was easily accommodated while retaining all desirable features. A uniformly and nonuniformly spaced filter bank for typical speech applications have been simulated with SWITCAP and three channels of the uniformly spaced filter bank have been constructed on a breadboard using discrete components. The results obtained agreed with design specifications, yielding a good approximation to linear phase in the passband and sharp attenuation in the stopband. Single-parameter and statistical multiparameter sensitivity analyses are presented.