Frequency of a Microwave Oven

Electromagnetic Radiation

• Electromagnetic radiation is a form of energy that includes radio waves, microwaves, ultraviolet, visible light, infrared, X-rays and gamma rays. While various forms of EM radiation share some common characteristics, specific forms are distinguished by their wavelengths, frequencies and how they interact with matter. EM radiation with frequencies between 1 GHz and 300 GHz are classified as microwaves. Due to their unique range of wavelengths, they are able to interact with water and most food substances at the molecular level.

Microwave Generation

• Basic microwave ovens have four essential components. The case, including the cooking chamber, provides physical support and a shield to prevent leakage of microwave radiation. The operating console typically consists of a switch and a timing device. Between the cooking chamber and the outer case of the oven are electronic circuits, a high-voltage step-up transformer and a specialized vacuum tube called a magnetron. The transformer supplies the magnetron with a 3,000- to 5,000-volt current. The magnetron converts the high-voltage electrical current to EM radiation in the form of microwaves.

How Microwaves Cook Food

• When microwave radiation strikes food, the food molecules become physically agitated. At this point, EM energy is transformed into kinetic energy. Friction between the moving food molecules generates thermal energy (heat), which warms or cooks the food.

Frequency of Microwaves in Home-Use Ovens

• Most microwave ovens for home use operate at a standardized frequency of 2.45 GHz, or 2450 million cycles per second.