Generalised transient response of bandpass transfer functions to f.s.k.- and p.s.k.-type signals

A method that enables an accurate evaluation to be made of the instantaneous frequency response of bandpass filters is presented, and an explicit expression is derived for the general case of a constant-amplitude discontinuous-phase f.s.k. signal. Curves of responses of a 4-pole filter are included as an example, both for the continuous- and discontinuous-phase f.s.k. signal. A byproduct of this technique also permits the computation of the instantaneous phase and frequency response due to a p.s.k. signal.