An Analog Front Of Near Field Communication Chips For Mobile Identification

Near Field Communication (NFC) is a 13.56MHz frequency wireless communication technology which enables the exchange of data between devices over about a 10 centimeter distance. NFC seems to be a technology without limits for the number of areas it can be used in. NFC is primarily aimed at usage in mobile phones. In recent years, the amount of RFID tags has increased rapidly. The technology is cheap and relatively simple.Firstly, the paper would talk about the technical characteristics and applications of NFC system. Then a brief summary of ISO/IEC 14443-2 protocol and the three NFC working modes would be given. Thirdly, three creative analog front circuits would be given, including the reader modulation part, the reader demodulation part and the reader clock sources part. A new type of reader RF front end circuit was proposed which including four parts (mix, filter and variable gain amplifier module, integration module, sample & hold module and bit decoding module). This circuit has the receiving capability of high sensitivity and better noise suppression. Besides, a structure of RFID tag would be given, which is one part of NFC system along with reader.The design is in accordance with ISO/IEC 14443 Type-A protocol. Detail simulation was given at the Cadence design environment with a 5V single voltage 0.5um CMOS process. The results of this work could be provided as reusable IPs in the form of hard or firm IPs for designing single-chip ISO/IEC 14443-compatible RFID interrogators.