Transmitter

A transmitter is an electronic device which with the aid of an antenna propagates an electromagnetic signal such as radio, television, telecommunications, etc.

A transmitter usually has a power supply, an oscillator, a modulator and audio, IF (intermediate frequency) and RF (radio frequency) amplifiers. Sometimes a device, for example, a cell phone contains both a transmitter and a radio receiver or transceiver. The modulator is the device which piggybacks (or modulates) the signal information onto the carrier radio frequency which is broadcast.