Group delay of a filter
This graph shows the group delay of a Butterworth filter, after equalization by a four poles GD equalizer (constant amplitude network).
The "Minimax" module of Radiosim has been used to tune the equalizer cells to a flat ceiling over 10 MHz.

Other examples : Fresnel plan
Eye diagram
Group delay of a feeder
Interferences
Bit Error Rate Multicarrier
amplification Constellation
Differential gain