The case of the dB scale is the same because electrical signals may vary over many orders of magnitude, for example, in a filter circuit, the magnitude of the transfer function in the passband may be several orders of magnitude larger than it is in the stop band. Due to the ...
The frequency response is of practical interest for the same reason, but also because it relates immediately and intuitively to the filter's function and its specification into pass band, transition band, and stop band. Generally the filter/system characteristic can be obtained by determining the ...