RFID Basics
RFID = Radio Frequency Identification
RFID stands for radio frequency identification. This technology allows transmission of data without contact and line of sight from a data medium, what is called a transponder, to a reader and vice versa.
The term transponder is formed from the two words transmitter and responder.
RFID system
The RFID reader works as a transmitting and receiving unit, and produces an electromagnetic field. This is detected by the antenna of the transponder and charges its energy storage mechanism. As a result, the microchip contained in the transponder is activated and can receive commands from the reader through its antenna and also transmit.
When it responds, the transponder does not emit a magnetic field of its own, instead it modulates the magnetic field of the reader. This process is repeated for as long as the transponder and reader have a certain proximity to one another, or a connected system issues the appropriate command.