Radio Waves – Communicate via Radio Waves

• When we speak, our vocal chords create pressure waves or sound waves.
• These dissipate as they move further away, like ripples in a pond (attenuation).
• Human hearing detects frequencies between 20 – 20000 cycles per second (Hertz)

• A radio wave is generated by a transmitter and then detected by a receiver.
• An antenna allows a radio transmitter to send energy into space and a receiver to pick up energy from space.
• Transmitters and receivers are typically designed to operate over a limited range of frequencies.

Sound waves are the movement of energy (not molecules):

• Air is compressed and expanded
• Sine wave / curve shape

Sound waves don’t move the molecules, similar to a Mexican wave at a sporting stadium, the people don’t move but the wave energy does.

• Wavelength is the distance between each cycle
• Amplitude is the ½ height of each cycle
• Frequency is the number of cycles per second

Radio Waves use excitement of electromagnetic waves:

• Can travel through space
• No air or water required