In phase demodulation, the information to be extracted is neither in the amplitude variations nor in frequency variations but the information is in the variation of the instantaneous phase of the carrier. So the phase demodulation should be programmed in such a way that the output amplitude varies linearly according to the instantaneous phase of the incoming signal.

Phase demodulator is made by a frequency demodulator block followed by an integrator as shown in figure 1.

Figure 1: Phase demodulation 

At the end of this experiment, students should investigate how the change of carrier frequency and waveform shape effects phase demodulation.