NHE2484: Communication System | Assignment
Added on - 17 Oct 2019
NHE2484: Communication SystemFM Demodulation
NHE2484: Communication SystemAbstractThe PLL CD4046 IC is used as a demodulator circuit for frequency demodulation
NHE2484: Communication SystemContent page
NHE2484: Communication SystemIntroductionThe Phase-Locked Loop (PLL) circuit is used in control andcommunication systems. A phase locked loop circuit consists of threemain components; a voltage-controlled oscillator (VCO), a phasecomparator, and a low-pass filter . When used as a FM demodulator, theinput to the PLL circuit is a FM signal and the output (demodulated signal)is the output from the low-pass filter. The operation of this demodulator isdescribed as follows: The phase comparator detects the differencebetween the phase (or frequency) of the VCO output and that of the inputsignal. The function of low-pass filter is to filter phase error and then it isused to adjust the VCO . That is the phase of the VCO phase locks on thephase of the input signal.