7.2.2 impulse Response of Ideal Filters o ldeal frequency selective filters are characterized by passband and stopband with sharp transitions from passband to stopband o Four such commonly used filters are the lowpass highpass, bandpass, and bandstop filters whose ideal frequency response have been discussed7.2.2 impulse Response of Ideal Filters  Ideal frequency selective filters are characterized by passband and stopband with sharp transitions from passband to stopband.  Four such commonly used filters are the lowpass, highpass, bandpass, and bandstop filters whose ideal frequency response have been discussed