Need help in FM modulator and PLL-based FM demodulator

Thread Starter


Joined Sep 24, 2011
Hi guys! This is my first time posting in this forum.

For my project, i am making a simple FM modulator and a PLL-based FM demodulator. I have read many articles and sources in the net but i cant seem to find the right answers to my questions. I hope you guys can help me.

For FM modulator:

I have seen FM modulator circuit using varactor diode and IC. But, in my project, a carrier frequency is already given by a function generator. I was wondering where can i input the carrier frequency generated. My problem the design of the circuit. Also, I cant seem to find out the calculations for the value of capacitors and resistors and inductors.

For PLL demodulator:
I would like to discuss this after i finished the FM modulator. I think i need to have a good understanding of the circuit of the FM modulator first before proceeding to this. :))

I hope you can help me guys.