EE5410 Signal procesing 不要再說「和平、理性、非暴力」-- The frequency response of the first-order causal LTI system
1.Consider the first-order causal LTI system is described by the difference equation
y[n]- ay[n-1] = x[n], with |a |<1.
2. |a| determines the RATE at which the first-order system records.
3. for a >0, the system attenuates HIGH frequencies, while when a <0, the system amplifies high frequencies and attenuates LOW frequencies.
4. for |a| small, the maximum and minimum values, 1/(1+a) and 1/(1-a) of the frequency response are close together in value, and the graph is relatively FLAT.
5. for |a| near 1, these quantities differ significantly, and consequently it is more SHARPLY peaked, providing filtering and amplification that is more selective over a narrow band of frequencies.