In fact, this method of shifting PFRC is an integration of EDF and device which performs the phase shift through a predetermined angle (in any direction).
Expressions (5) and (6) are the mathematical models of EDF without PFRC shifting.
This makes it possible to work with two output values which give the relative PFRC shift of [pi]/2 radian.
Moreover, it is necessary to provide the coincidence for PFRC of certain EDF in order to form a continuous band pass at the expense of multiplying uneven EDFs by minus unit.
In the generic mathematical model, the PFRC is shifted through angle [pi]/2 by means of isolation of the real or imaginary component of complex output signal.
The gradual shifting of PFRC is achieved by means of rotating input samples through an additional angle in their vector addition.