How Rfid Works

- Jan 22, 2019-

The basic working principle of RFID technology is not complicated: after the tag enters the magnetic field, it receives the RF signal from the reader, and sends the product information (passive tag or passive tag) stored in the chip by the energy obtained by the induced current, or by The tag actively sends a signal of a certain frequency (Active Tag, active tag or active tag), and the reader reads the information and decodes it, and sends it to the central information system for data processing.


A complete RFID system consists of a reader and an electronic tag, the so-called transponder and application software system. The working principle is that the Reader emits a specific frequency of radio wave energy to drive the circuit. The internal data is sent out, and the Reader receives the interpretation data in order, and sends it to the application for corresponding processing.


According to the communication and energy sensing between the RFID card reader and the electronic tag, it can be roughly divided into two types: inductive coupling and backscatter coupling. Generally, the low-frequency RFID mostly adopts the first type, and the higher frequency mostly adopts the second method.


The reader can be a read or read/write device depending on the structure and technology used, and is an RFID system information control and processing center. The reader usually consists of a coupling module, a transceiver module, a control module, and an interface unit. The half-duplex communication is generally used for information exchange between the reader and the transponder, while the reader provides energy and timing by coupling to the passive transponder. In practical applications, management functions such as collection, processing, and remote transmission of object identification information can be further implemented through Ethernet or WLAN. The transponder is the information carrier of the RFID system, and the transponder is mostly composed of a coupling element (coil, microstrip antenna, etc.) and a microchip to form a passive unit.