Introduction - If you have any usage issues, please Google them yourself
Interpolation function superimposed between sampling points of the frequency response is weighted within each sampling point and the formation of, and thus have a certain degree of approximation error. The size of this error depends on the shape of the ideal frequency response and the ideal frequency response characteristic change is more gentle, interpolated and more close to the ideal value, the smaller the approximation errors Conversely, if the sampling point between the ideal frequency response characteristics of the steeper the change, and then the interpolated the larger the error between the ideal value, and thus in the ideal filter both sides of the discontinuity point, will produce spikes occurs ripple in the passband and stopband. Actual design frequency sampling filter frequency response is shown in Figure 1. Figure 1 shows, the actual filter stopband attenuation depending on the interpolation value of the size of the first side-lobe amplitude of the function that determin