Question

What type of filter produces a predictable phase shift characteristic in all frequencies?

(a) Band pass filters

(b) High pass filters

(c) Low pass filters

(d) All pass filters

I have been asked this question by my college director while I was bunking the class.

The question is from Filters topic in chapter Fundamentals of Electronics of Avionics

Answer 1

Right option is (d) All pass filters

Explanation: An all pass filter passes all frequencies equally well over its design range but has a fixed or predictable phase shift characteristic. Filters normally attenuate the signal applied for some values of frequency whereas an all pass filter retains the signal level at all frequencies.