Radio Frequency Identification (RFID), also known as Radio Frequency Identification (RFID) technology, is a type of automatic identification technology that uses wireless radio frequency for non-contact bidirectional data communication. It uses wireless radio frequency to read and write recording media (electronic tags or RF cards) to achieve identification goals and data exchange. It is considered one of the most promising information technologies of the 21st century

Wireless radio frequency identification technology achieves the purpose of identification by combining wireless communication with data access technology through contactless rapid information exchange and storage technology, and then connecting to a database system to achieve contactless bidirectional communication. It is used for data exchange and connects an extremely complex system. In the recognition system, electronic tags are read, written, and communicated through electromagnetic waves. According to the communication distance, it can be divided into near field and far field. Therefore, the data exchange method between read/write devices and electronic tags is correspondingly divided into load modulation and backscatter modulation.