Anti-alias filters for tuner applications

Techniques are presented for the design of nonrecursive linear phase digital filters suitable for attenuating signal components which alias into baseband components upon desampling (decimation). The techniques are aimed primarily at applications requiring very high speed operations upon broadband waveforms which contain narrowband signals of interest, as is typically encountered in digital tuners. Hardware simplicity is stressed by constraining all filter coefficients to be no more complex than integer powers of 2. An example is given of a high speed decimate-by-six anti-alias filter implemented for use in a digital sub-band tuner.