Hence the first commercial microwaves being named "Radar Range".
Raytheon had invented the microwave oven in 1947
Percy Spencer, an engineer (radar tube designer) working for Raytheon durng WWII, invented the first microwave oven after World War II from radar technology developed during the war. Named the "Radarange", it was first sold in 1947. Raytheon introduced the commercial Radarange Model 1611 in 1954.
Raytheon later licensed its patents for a home-use microwave oven that was first introduced by Tappan in 1955, but these units were still too large and expensive for general home use. The countertop microwave oven was first introduced in 1967 by the Amana Corporation, which was acquired in 1965 by Raytheon.
One day while building magnetrons, Spencer was standing in front of an active radar set when he noticed the candy bar he had in his pocket had melted. Spencer was not the first to notice this issue, but he was the first to investigate it. He decided to experiment using food, including popcorn kernels, which became the world’s first microwaved popcorn. In another experiment, an egg was placed in a tea kettle, and the magnetron was placed directly above it. The result was the egg exploding in the face of one of his co-workers, who was looking in the kettle to observe. Spencer then created the first true microwave oven by attaching a high density electromagnetic field generator to an enclosed metal box. The magnetron emitted microwaves into the metal box blocking any escape, allowing for controlled and safe experimentation. He then placed various food items in the box, while observing effects and monitoring temperatures.
Raytheon filed a patent on October 8, 1945 for a microwave cooking oven, eventually named the Radarange. In 1947 the first commercially produced microwave oven was about 6 feet tall, weighed about 750 lbs, and cost between $2,000 and $3,000. In 1967 the first relatively affordable ($495) and reasonably sized (counter-top) microwave oven was available for sale.