Radio waves carry information by modulating certain characteristics of the wave. Here’s how it works:
- Carrier Wave:
A radio wave by itself is just a repeating signal. To transmit information like sound, images, or data, it acts as a carrier. - Modulation Techniques:
Information is added to the carrier wave by changing its properties:- Amplitude Modulation (AM): The height (amplitude) of the wave is varied.
- Frequency Modulation (FM): The frequency of the wave is varied.
- Phase Modulation (PM): The phase (position in the wave cycle) is altered.
- Digital Modulation (e.g., QAM, PSK): Used in modern communication to carry digital data.
- Transmission and Reception:
The modulated wave is transmitted through antennas. A receiving antenna picks up the wave, and a radio receiver extracts the embedded information by demodulating it. - Applications:
This method is used in radio and TV broadcasting, mobile phones, Wi-Fi, satellite communication, and more.
In short: Radio waves carry information by altering the wave’s features in a controlled way, which can then be interpreted by receivers to reconstruct the original message.