The working principle of RFID reader

RFID reader (reader) through antenna and RFID electronic tag wireless communication, can realize the label identification code and memory data read or write operation.  A typical reader consists of a high frequency module (transmitter and receiver), a control unit, and a reader antenna.  

Among them, electronic tag is also known as radio frequency tag, transponder, data carrier;  Readers are also known as readout devices, scanners, communicators, readers (depending on whether electronic tags can wirelessly rewrite data).  The spatial (contactless) coupling of radio frequency signal is realized between the electronic tag and the reader by coupling element. In the coupling channel, energy transfer and data exchange are realized according to the timing relationship.  

There are two types of rf signal coupling that occur between a reader and an electronic tag.  

(1) Inductive coupling.  Transformer model, through space high-frequency alternating magnetic field to achieve coupling, according to the law of electromagnetic induction.  

(2) Electromagnetic backscattering coupling: radar principle model, the electromagnetic wave emitted, after touching the target reflection, at the same time carry back the target information, according to the electromagnetic wave space propagation law.