Optimized windows for FIR filter design to perform maximally flat decimation stages in signal conditioning

New cosine windows, the coefficients of which have been computed through a simple optimization procedure, are proposed to minimize the sidelobe ripples. This allows maximally flat low-pass finite-duration impulse-response (FIR) filter realizations in a multistage-decimation process. In digital measuring devices this strategy is performed in order to limit the amount of data to the storage capabilities of the processor, in conjunction with filtering the data set available after oversampling to remove digitally the noise power produced by quantization. The consequent increase of the number of effective bits improves the dynamic performance of digital instrumentation, especially at lower frequencies