Radio Transmitter Block Diagram

This block diagram of a radio transmitter in a communication system is very simple and basic. It is generalised for AM and FM types of modulation, and consists of four subsystems. Communication is the transfer of meaningful information from one location to another. We start with the conversion of sound waves in the air into electrical energy. A transducer, which is usually a microphone, does this job very well.

The carrier wave generator is an oscillator, which produces pure un-modulated sine waves in the radio frequency range. It usually consists of a tuned oscillator circuit that produces a carrier wave of a specific frequency.

The signal from the carrier wave generator, and transducer, feeds a modulator, which encodes the carrier signal with the information we wish to send. There are two types of modulation methods; in AM, the amplitude of the carrier modulates, whilst in FM the frequency of the carrier modulates.

The transmitter block is usually responsible for generating electromagnetic waves that travel through the air.