7.1 Ideal Filters
Filtering refers to the time or frequency-domain processing of a signal, which is performed to enhance the required features or to remove unwanted frequency components. Ideal filters allow a band of frequencies and reject all other frequencies. Depending on their frequency-domain characteristics, filters can be classified as
i. Lowpass
ii. Flighpass
iii. Bandstop
iv. Bandpass
The magnitude responses of these ideal filters are shown inFigure 7.1 (for positive frequencies only). For real filters, the magnitude response is symmetric around ω = 0. In this section, we define the magnitude response of these ideal filters and compute their impulse responses, assuming that the phase ...
