Design Of 13.56MHz RFID Analog Front-end

RFID is a technology of contactless automatic identification,It make use radio frequency signals the principle of spatial coupling and transmission to identify the object which is stationary or moving automaticly.Comparing with the traditional bar code, magnetic cards and IC card, Radio frequency card has the function of large capacity,long identification range, strong penetrating ability, strong anti-dirt, non-contact,fast reading speed, no wear and tear, free from the impact of environmental, long life, easy to use and anti-collision, and can deal with several cards in the same time. In the foreign countries, Radio Frequency Identification technology has been widely used in industrial automation, business automation, transport, control and management and many other fields.This paper mainly designs the circuit of analog front end which in line with ISO14443 standard in the contact-less tag chip. The content as follows:the standard of ISO 14443, the working principle and theoretical basis of the Radio frequency identification system, the rectifier and filter circuit, the cicuit of digital or analog supply generating, the cicuit of clock recovery, the circuit for modulation and demodulation, the circuit for limiting voltage and electronic-static protecti-on,the circuit for producing reset signal and the last whole analog front-end design etc.Some circuits such as rectifier and filter circuit, digital or analogy supply generating circuit,100% and 10% demodulation circuit are specially introduced in this paper.0.5um 20V high voltage technology of CSMC is used for designing the analog front-end. the layout is drawn,given DRC,LVS and LPE by virtuoso and assure tools.Giving the simulation to the entire analog front-end circuit.the last simulation result shows that the performance of analog front-end circuit works good and meets the requirement.