Radio Frequency (Rf) Definition
Radio frequency (RF) is a measure of the number of oscillations of a signal per second in the electromagnetic spectrum. The electromagnetic spectrum is the range of frequencies of electromagnetic radiation and their corresponding wavelengths. The lower the frequency, the longer the wavelength; the higher the frequency, the shorter the wavelength. RF waves are used for communications and other purposes.
The term radio frequency (RF) refers to alternating current (AC) having characteristics such that, if fed into an antenna, an electromagnetic (EM) field is generated that propagates through free space without being attenuated by the atmosphere. RF AC can be produced by oscillators or electronics circuits called amplifiers. The field produced by an antenna can be detected by another antenna tuned to receive that particular frequency range.
When RF energy is transmitted, it travels in a straight line away from the antenna at the speed of light until it strikes an object. When it strikes an object, two things happen: The energy is either reflected back toward the source or it is absorbed by the object it hit. If enough energy is absorbed,the object becomes hot