What Is Microwave Radiation?

Microwave is a type of electromagnetic radiation with wavelengths that are shorter than radio waves and infrared, but longer than ultraviolet and visible light. Microwaves travel line-of-sight and are not absorbed by water or gases in the atmosphere like other frequencies such as far infrared, terahertz, and ultrahigh frequency (UHF). Microwaves are used for communication transmission towers, radar systems for weather tracking, police car speed guns, air traffic control, and microwave ovens. Microwave radiation is also emitted naturally by stars, including our Sun, and natural objects such as water vapor and dust clouds. Microwave radiation is also a part of the cosmic microwave background radiation that fills the universe and provides clues to its origin in the Big Bang.

The most familiar use of microwaves is the food-cooking microwave oven. In this, a magnetron oscillator feeds microwaves into a closed metal box with food, which a special reflector inside the oven turns into heat energy by forcing the water molecules in the food to vibrate. The resulting friction creates heat and cooks the food.

Microwaves can also be used to process materials in industry, such as drying and curing plywood and rubber, and in agriculture, such as raising crops and growing potatoes. In addition, the US Food and Drug Administration (FDA) regulates microwave oven manufacturers to ensure that their products meet safety performance standards created and enforced by the FDA.