what is rf

Radio frequency (RF) refers to the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around 20 kHz to around 300 GHz. This range is roughly between the upper limit of audio frequencies and the lower limit of infrared frequencies. RF is used in radio technology, among other uses, because energy from an oscillating current can radiate off a conductor into space as radio waves. RF is measured in units called hertz (Hz), which represent the number of cycles per second when a radio wave is transmitted. RF currents have special properties not shared by direct current or lower audio frequency alternating current, such as the 50 or 60 Hz current used in electrical power distribution. For example, energy from RF currents in conductors can radiate into space as electromagnetic waves (radio waves), which is the basis of radio technology. RF is also used in nonsurgical cosmetic procedures to firm sagging skin.