Chapter 3 Lesson 3

By: Lukas, Will, Riley, and Christian


Key 1 - Radio waves carry information from the antenna of a broadcasting station to the receiving antenna of your radio.

Key 2 - Cell phones transmit and receive signals using high-frequency microwaves.

Key 3 - Communications satellites receive radio, television, and telephone signals and relay the signals to receivers on Earth.


Amplitude Modulation- A method of broadcasting signals by changing the amplitude of a wave.

Frequency Modulation- A method of broadcasting signals by changing the frequency of a wave.

How do Radio Waves Transmit Information

Radio waves transmit signals for radio programs. Charged particles vibrating inside transmission antennas produce radio waves. Transmission antennas send out, or broadcast, radio waves in many directions.

Broadcasting Signals

Radio stations broadcast signals in two frequency bands. These bands are amplitude modulation and frequency modulation.

How Cell Phones Work

Cell phones work in a cellular system. A cellular system works by dividing regions into many small geographical areas. Each one of these geographical areas has one or more towers that relay signals to a central hub.

How Satellite Communication Works

The satellites that orbit earth send information around the world. Communication satellites work like receivers and transmitters of a cellular phone system.
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Satellite Phone Communication

Radio waves from one place are sent up to a communication satellites. The satellites transmits the waves back to the receiving phone on earth.
Satellite communication - Space technology has witnessed a phenomenal growth