Microwave How it Works

Microwaves are very short, high-frequency radio waves. A microwave oven is similar to a miniature broadcasting system. Microwaves are the same types of energy as AM, FM, or CB radio, but the wavelength is much shorter. 

 

While other types of radio waves broadcast over a distance, the microwave broadcasting system is self-contained. When the door is closed and the oven is turned on, a transmitter, called a magnetron, sends a signal to a receiver within the oven. The moment the door is opened, the magnetron stops broadcasting, just as a radio will not play if the station has "signed off". No energy will be broadcasted into the oven cavity while the door is open.

 

The receiver deflects the microwave energy into the metal-lined oven cavity, where it agitates the food molecules. Since microwaves cannot penetrate metal, all the energy remains inside the oven, where it turns to heat in the food.