Study of Frequency Demodulation

 

Experiment Name: Study of Frequency Demodulation.

 

Required Apparatus:

        I.            Frequency Modulation Transmitter KIT

·         Balanced Modulator -1

Modulation: Frequency Modulation

Carrier Input: 1-1000 KHz; Modulating Input: 0.1-1500 KHz

·         Function Generator [Frequency: 500-1500 KHz]

·         Voltage Controlled Oscillator [Frequency: 500-1500 KHz]

      II.            Power Supply

    III.            Oscilloscope

    IV.            Connectors

      V.            Frequency Demodulation Receiver KIT

 

Block Diagram:

 

 

 

Circuit Diagram:

 

Figure: Circuit Diagram of Frequency Demodulation

 

Input/Output Waveshape:

 

Figure: (a) Input Message Signal, (b) Frequency Demodulated Output Signal

Discussion:

From the experiment, we know about the process of frequency demodulation. With this process, we can recover the original modulating signal from a frequency modulated signal. There are two methods for frequency demodulation such as direct method and indirect method. From the experiment we found that the output of demodulated signal depends only on the frequency variation of the input signal.

 

Conclusion:

While doing the experiment, some precautions should be taken. Sometimes we can’t get the accurate wave shape because of the loose connection. And there was some distortion while calibrating the oscilloscope. So, we have to check the connection properly and we have to calibrate the oscilloscope accurately to get the accurate or proper wave shape.