Impulse response of ideal filters

1. What is the impulse response of the ideal filter?
2. How do you find the impulse response of a filter?
3. What is the impulse response of a high-pass filter?
4. Why ideal filters are not realizable?

What is the impulse response of the ideal filter?

Thus, the impulse response of an ideal lowpass filter is a sinc function.

How do you find the impulse response of a filter?

First, remember that the impulse response is literally "the response of a system to an impulse." If the input is an impulse (x[n]=δ[n]), then the output is the impulse response (y[n]=h[n]). which is sometimes written as a vector, like h[n]=[1,2] for n=0,1. so that the impulse response is defined in a recursive way.

What is the impulse response of a high-pass filter?

High-pass filters have zero gain at DC (zero frequency), achieved by making the sum of all the points in the filter kernel equal to zero. Imagine a simple analog electronic circuit. If you apply a short pulse to the input, you will see a response on the output.

Why ideal filters are not realizable?

The Paley and Wiener criterion implies that ideal filters are not physically realizable because in a certain frequency range for each type of ideal filters. Therefore, approximations of ideal filters are desired.