Electromagnetic fields, radio waves, microwaves and wireless signals are referred to as radio frequency (RF) energy. RF energy is all around us. RF is used in various electronics and appliances, which include radio and television broadcasting, cellular telephones, satellite communications, microwave ovens, radars, and industrial heaters and sealers. These are just a few applications.

Electromagnetic waves are measured by wavelength and frequency. Wavelength is the distance covered by one complete cycle of the electromagnetic wave. Frequency is the number of electromagnetic waves in one second, also known as a Hertz or Hz. One Hz equals one cycle per second. One megahertz (MHz) equals one million cycles per second. Generally, microwaves are radio frequencies measuring more than 1 GHz.