A transmitter generates and sends signals. It takes information and encodes it onto a carrier wave. It amplifies the signal. It sends it through an antenna, a cable, or a fiber. The transmitter is the source. The receiver is the destination.

Transmitters come in many forms. A radio transmitter broadcasts audio. A TV transmitter broadcasts video. A cell tower transmitter sends cellular signals. A fiber transmitter converts electrical signals to light. A satellite transmitter sends signals to Earth. Each is tuned to specific frequencies and protocols.

Transmitter components

• Oscillator: generates the carrier
• Modulator: encodes information
• Amplifier: boosts power
• Antenna: radiates the signal
• Filter: removes unwanted frequencies

Transmitters must be licensed. They must operate within power limits. They must not interfere with other transmitters. Governments regulate them. Engineers design them. They are the voice of the network. Without them, there is nothing to receive.