radio wave

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How does a radio convert waves into sound?

Schematic diagram showing the propagation of high-frequency (shortwave) radio waves by reflection off the ionosphereSpecific ionization conditions vary greatly between day (left) and night (right), causing radio waves to reflect off different layers of the ionosphere or transmit through them, depending upon their frequency and their angle of transmission. Under certain conditions of location, ionization, frequency, and angle, multiple “skips,” or reflections between ionosphere and Earth, are possible. At night, with no intervening layers of the ionosphere present, reflection off the F layer can yield extremely long transmission ranges.

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radio wave

physics

Written and fact-checked by The Editors of Encyclopaedia Britannica

Last Updated: Apr 2, 2024 • Article History

radio waves

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Category: Science & Tech

Key People:: Vitaly Ginzburg; Sir Oliver Joseph Lodge; Heinrich Hertz; George Francis FitzGerald

Related Topics:: whistler; carrier wave; radio-frequency spectroscopy; ground wave; extremely low-frequency radiation

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radio wave, wave from the portion of the electromagnetic spectrum at lower frequencies than microwaves. The wavelengths of radio waves range from thousands of metres to 30 cm. These correspond to frequencies as low as 3 Hz and as high as 1 gigahertz (10⁹ Hz). Radio-wave communications signals travel through the air in a straight line, reflect off of clouds or layers of the ionosphere, or are relayed by satellites in space. They are used in standard broadcast radio and television, shortwave radio, navigation and air-traffic control, cellular telephony, and even remote-controlled toys. (For a fuller treatment, see electromagnetic radiation: ...(100 of 102 words)

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