§4.2 The Frequency Response n some cases,the magnitude function is specified in decibels as G(@)=20l0g10 H(ei)dB where G(@)is called the gain function The negative of the gain function A(O)=-G(0) is called the attenuation or loss function§4.2 The Frequency Response • In some cases, the magnitude function is specified in decibels as G(ω) = 20log10| H(ejω) | dB where G(ω) is called the gain function • The negative of the gain function A(ω) = - G(ω) is called the attenuation or loss function