Field Guide · term

Also known as: radio wave, radio waves

A radio wave is electromagnetic radiation whose frequency lies in the radio range of the electromagnetic spectrum.1 Radio waves travel at the speed of light and carry information wirelessly when their amplitude, frequency, or phase is varied — a process called modulation.

wavelength (λ) amplitude
A radio wave is described by its wavelength, amplitude, and frequency (cycles per second).

How it works

A transmitter drives alternating current into an antenna, radiating a self-propagating electric and magnetic field. A distant antenna converts the passing field back into a tiny current that a receiver amplifies and decodes.

Relevance to SDR

Radio waves are the raw input to any receiver. An SDR digitises a slice of them into IQ data for software to process.

Sources

  1. Radio wave — Wikipedia, on radio-frequency electromagnetic radiation and its use for wireless communication. ↩

See also

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