# What should be the sample frequency to test the response of a filter?

I am testing the frequency response as a filter as below, what should be the sample rate of the chirp signals, someone told me it should be at least 2 times of the input signals frequency, someone said it should be at least 10 times? Why?

• 1 is the filter continuos time filter or discrete time filter ? 2 Is the block signal sampling representing a sampling circuit ? 3 If the filter is a discrete time signal, what sampling frequency is it designed for ?
– AJN
Sep 29 '21 at 18:51
• A1: It is a discrete time filter running in my software A2: It is a signal processing module running at specified frequency, I think it could be treated as a sampling circuit. A3: what do you mean? The bandwidth of the filter?
– LHX
Sep 30 '21 at 2:42
• When designing a discrete-time filter, the coefficients of the filter is a function of the sampling rate at which the filter works. So if you have the discrete-time filter coefficients already designed, then the sampling rate at which it works is already known. The signal sampling block should supply the samples at that same rate.
– AJN
Sep 30 '21 at 11:06
• Please add more details and context for the question. The answer would depend on whether the chirp is the thing which is already decided / fixed or if the filter is the thing which is already decided / fixed.
– AJN
Sep 30 '21 at 11:08