what is a Sinc filter
The rectangular function, the frequency response of the sinc filter. In signal processing, a sinc filter is an idealized filter that removes all frequency components above a given cutoff frequency, without affecting lower frequencies, and has linear phase response.The filter's impulse response is a sinc function in the time domain, and its frequency response is a rectangular function.It is an ideal low-pass filter in the frequency sense, perfectly passing low frequencies, perfectly cutting high frequencies; and thus may be considered to be a brick-wall filter.he sinc filter is not bounded-inputâbounded-output (BIBO) stable. That is, a bounded input can produce an unbounded output, because the integral of the absolute value of the sinc function is infinite. A bounded input that produces an unbounded output is sgn(sinc(t)).