Determining Phase Shift from Zverev's Filter Book

Zverev's Filter book is the ultimate filter handbook, but it's not easy to use.

The attenuation and group delay plots are plotted vs. normalized frequency Ω, which is f/3dB cutoff frequency.

To figure out the phase shift, simply find the area under the group delay plot from 0 to the normalized frequency of interest.

Group Delay = - dφ/dΩ

Therefore

φ = ∫(TD*dΩ) from Ω=0 to Ω