Microwave

Microwave, electromagnetic wave in the superhigh frequency radio spectrum (890 to 300,000 megacycles per sec). Microwaves are electromagnetic radiations of wavelength between .03937 in (1 mm) and 1 ft (30 cm). Microwaves first received attention through the use of radar in World War II (1939–45); today they are used in radar, telecommunications, and spectroscopy and for cooking (microwave ovens).

See also: Radio; Television; Ultrahigh frequency waves.