§4.2 The Frequency Response H(eJo), in general, is a complex function of o with a period2兀 It can be expressed in terms of its real and imaginary parts H(ejo)=hre(ejo)+j Him(ejo) or, in terms of its magnitude and phase, H(ejo)=H(ejo )l ee(@) where B(o=argH(eJo)§4.2 The Frequency Response • H(ej), in general, is a complex function of  with a period 2p • It can be expressed in terms of its real and imaginary parts H(ej)= Hre(ej) +j Him(ej) or, in terms of its magnitude and phase, H(ej)=|H(ej)| e() where ()=argH(ej)