An oven that heats food using microwave radiation. The first microwave oven was demonstrated by Westinghouse at the 1933 World's Fair in Chicago. Its 10-kilowatt shortwave radio transmitter cooked meat and potatoes between metal plates. In 1946, Ratheon introduced its Radarange oven using the company's magnetron tubes, and Raytheon engineer Percy Spencer applied for patents. In the 1950s, Raytheon ovens were sold to restaurants for high-speed cooking. By the late 1960s, microwave ovens began to appear in homes, and of course, today microwave ovens are found in most every household in the developed world. See
magnetron.