Theory -70 :- FM Transmitter Block Diagram, Working Principle

The FM Transmitter Block Diagram And Working Principle.

FM transmitter circuit is used to produce and transmit the Radio Frequency signal wirelessly. FM transmitter circuit can produce the radiofrequency waves which are transmitted through the antenna. Here you will see the block diagram of FM Transmitter Circuit which gives you the idea of working principle of FM Transmitter Circuit.

 

FM Transmitter Block Diagram

Here you can see a simple block diagram of FM Transmitter.

 

FM Transmitter Working Principle

The main function of an FM Transmitter Circuit is to transmit the sound using radio waves. So, at first, an FM Transmitter Circuit converts the sound or audio into radio wave then it transmit.

You can see, in the block diagram of the FM Transmitter, the first block is the Microphone. The microphone is a Transducer which can convert the sound energy into an audio signal in the form of electrical energy. So microphone is a source of an audio signal. In this block diagram, the microphone is used as the source of the audio signal but it may be another audio source also.

The next block is Audio Pre-amplifier. The audio pre-amplifier is used to amplify the audio signal coming from the microphone.   

The next one is the Modulator. The modulator circuit is the main part of an FM transmitter circuit. It converts the audio signal into a radio signal which is to be transmitted. The modulator circuit takes two signal as input one is the audio signal coming from the audio pre-amplifier and another is carrier signal.

 

The carrier signal is a pure radio wave that is produced by the oscillator circuit.
The modulator circuit modulates the RF signal according to the audio signal and produces the modulated RF signal as the output. 

The next stage is radio signal amplification. The RF amplifier circuit amplifies the modulated RF signal coming from the modulator. The modulated radio signal coming from the modulator circuit has a very low amplitude so it cannot be transmitted for a long distance. So, RF amplifier is used to amplify the radio signal which can be easily transmitted for a long distance. Then the amplified radio signal is fed to the antenna for the transmission of signal.