The basic principle of RFID technology is not complex: the label into the field, RF signals received by the reader, by sending the obtained current energy out of the product information stored in the chips (passive tags or passive tags), signals or by active tags send a frequency (Active Tag, active tag or active label), the reader will read and decode the information, sent to the central information system on the data processing.
A complete set of RFID system, by the electronic tag reader and transponder is three parts and application software system called the composition, the working principle of the Reader launch a specific frequency radio wave energy is used to drive the circuit, the internal data is sent, the Reader in the order of receiving data for interpretation, application do the corresponding processing program.
The communication and energy sensing between RFID card reader and electronic tag can be roughly divided into two types: inductive coupling and backscatter coupling. Generally, the low frequency RFID mostly adopts the first type, while the higher frequency is mostly used in second ways.
Depending on the structure and technology used, the reader can be a read or read / write device, a RFID system, an information control and processing center. The reader is usually composed of a coupling module, a transceiver module, a control module and an interface unit. Generally, half duplex communication is used to exchange information between readers and transponders, while the reader provides energy and timing to the passive transponder by coupling. In practice, Ethernet, WLAN and other functions can be used to collect, process and transfer remote identification information. The transponder is the information carrier of the RFID system, and the transponder mostly consists of a coupling element (coil, microstrip antenna, etc.) and a microchip.