How RFID Cards Work

The basic working principle of RFID technology is not complex: After a tag enters a reader, it receives the RF signal emitted by the reader, and uses the energy obtained by the induced current to transmit product information stored in the chip (Passive Tag, Passive Tag, or Passive Tag), or the tag actively sends a signal of a certain frequency (Active Tag, Active Tag, or Active Tag). After the reader reads the information and decodes it, Send to the central information system for relevant data processing.
A complete RFID system consists of a reader, an electronic tag, or so-called transponder, and an application software system. Its working principle is that the reader emits radio wave energy at a specific frequency, which is used to drive the circuit to send out internal data. At this time, the reader sequentially receives and interprets the data and sends it to the application for corresponding processing.
The communication and energy sensing methods between RFID card readers and electronic tags can be roughly divided into two types: inductive coupling and backscatter coupling. Generally, low-frequency RFID mostly uses the first method, while high-frequency RFID mostly uses the second method.
The reader can be a read or read/write device depending on the structure and technology used, and it is the information control and processing center of the RFID system. A reader usually consists of a coupling module, a transceiver module, a control module, and an interface unit. Generally, half duplex communication is used between readers and tags for information exchange, while readers provide energy and timing to passive tags through coupling. In practical applications, management functions such as collection, processing, and remote transmission of object recognition information can be further implemented through Ethernet or WLAN.