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6 votes

Why is the time domain low-pass filter the "sinc" shape?

One way to think about it is the requirement of what a filter does, and what is the relation between the time domain and frequency domain plots of the signal or the filter. This also requires to know ...
Justme's user avatar
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20 votes

Why is the time domain low-pass filter the "sinc" shape?

It is a good way to understand the lowpass behavior of sinc function (as well as the convolution) through visualization. I've made some modification on this animated convolution project and here are ...
ZR Han's user avatar
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5 votes

Why is the time domain low-pass filter the "sinc" shape?

Perhaps one way to see the sinc is as a special moving average filter. As you noted, the lower the cutoff frequency (filtering out higher frequencies), the wider the sinc mainlobe. This corresponds to ...
Gillespie's user avatar
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0 votes

What is the reason of existence of Fourier transform? (Why we use Fourier transform?)

The Taylor series attempts to model a limited piece of a function or a data series using a weighted sum of polynomials. This only works for relatively small values of x or t. The Fourier ...
9herbert9's user avatar
0 votes

“The Fourier transform cannot measure two phases at the same frequency.” Why not?

If you change the phase at a constant frequency, FFT calculates a different result. Unfortunately, it is common practice to erase the phase by forming and displaying the magnitude (see line 7 in the ...
9herbert9's user avatar

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