Signals and Systems

12.4 SPECIFICATIONS OF PHASE RESPONSE

We can write the frequency response of a filter in terms of real and imaginary part as

 

H(ω) = H_R(ω) + jH_I(ω)     (12.21)

 

where H_R(ω) and H_I (ω) are the real and imaginary part of H(ω).

We can also write H(ω) in terms of magnitude response |H(ω)| and phase response θ (ω) as

 

and     

where H(ω) is a continuous function of ω. If the frequency response of a digital filter is expressed in the following continuous phase form

 

H(ω) = A(ω)e^jωτ_p     (12.24)

 

we can say that it is in linear phase form τ_p