Extra exam question E7F09
Subelement E7, PRACTICAL CIRCUITS· Group E7F
Why is an anti-aliasing filter required in a decimator?
- A.It removes high-frequency signal components that would otherwise be reproduced as lower frequency components (correct answer)
- B.It peaks the response of the decimator, improving bandwidth
- C.It removes low-frequency signal components to eliminate the need for DC restoration
- D.It notches out the sampling frequency to avoid sampling errors
WhyAn anti-aliasing filter is required in a decimator to remove high-frequency signal components that would otherwise be reproduced as lower frequency components. An anti-aliasing filter is required ahead of a decimator specifically to remove high-frequency signal components that, once the sample rate is reduced, would otherwise fold down and reappear disguised as false lower-frequency components, corrupting the decimated signal, answer A. It doesn't peak the decimator's response to improve bandwidth, doesn't remove low-frequency content for DC restoration, and doesn't specifically notch out the sampling frequency itself, preventing aliasing from higher frequencies is its actual job.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2024-2028 NCVEC Element 4 pool (public domain); the explanation above is original writing, see our methodology.
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