Foreword Radio Frequency Identification (RFID) is a non-contact automatic identification technology that automatically identifies the target object and obtains related data through radio frequency signals without any human intervention. Compared with the traditional automatic identification technology such as bar code, magnetic stripe, magnetic card and IC card, RFID technology has the advantages of high degree of automation, long recognition distance, large amount of stored information and strong environmental adaptability. Moreover, RFID technology has realized passive and Contact-free operation, easy to use, no mechanical wear and long life, can better ensure the safety of appliances. "Food is the world, food safety first" food safety issues, more and more people are concerned about the future can "feel free to eat." The safety of food is related to people's health and social stability. Especially after China's accession to the WTO, the security of food is even more related to China's foreign trade. Therefore, in today's highly developed science and technology, how to ensure food safety, the issue has become an important issue of law enforcement, justice, research departments, law enforcement departments, production and circulation departments and other aspects of concern. Radio frequency identification technology is an important technology in the 21st century. It has gradually become an important means to optimize food production and ensure food safety. And it has been widely used in food processing, traceability, production process optimization and anti-counterfeiting application. 1 radio frequency identification technology and principles RFID system must have two key capabilities, first automatic identification, data literacy; followed by data processing to meet the data storage and data conversion capabilities. General RFID system consists of the following three basic components: 1.1 electronic label General by the chip and coupled components, the main function is to complete the reader / writer communication. And bar code, magnetic cards, IC cards and other recognition of the same period or earlier compared to radio frequency identification card with non-contact, long working distance, suitable for harsh environments, can identify the advantages of moving targets. According to the different energy supply methods, RFID tags can be divided into passive tags, semi-active tags and active tags. Semi-active tags and active tags are powered by the battery attached to the electronic tags. Active tags can emit RF signals actively. In accordance with the different operating frequency, RFID tags can be divided into microwave, high frequency (UFH), high frequency (HF) and low frequency (LF) and other different types. Different frequency bands of RFID work on different principles, microwave and UHF RFID electromagnetic emission generally use the principle of high frequency and low frequency RFID tags generally use electromagnetic coupling principle. 1.2 reader Reader is used to read the label information equipment. The RFID reader controls the RF module to transmit and read signals to the tags and receive the responses of the tags, decode the object identification information of the tag, and transmit the object identification information and other related information on the tag to the host for processing. In most RFID systems, the reader transmits electromagnetic waves in an area (the size of the area depends on the operating frequency and antenna size). The card has an LC series resonant circuit, the same frequency and reader transmitter frequency. When the radio frequency card through this area, the electromagnetic wave excitation, LC resonant circuit resonance, so that there is a charge in the capacitor. At the other end of this capacitor, there is a one-way channel electronic pump, the charge within the capacitor to another capacitor for storage. When the accumulated charge up to 2V, this capacitor can be used as a power supply for other circuits operating voltage, the card data transmitted out or access to the reader data. After the reader receives the data of the card, it decodes and performs error checking to determine the validity of the data, and then transmits the data to the computer network through RS232, RS422, RS485 or wirelessly. A simple RFID product is a non-contact IC card, and complex RFID products can interface with external sensors to measure, record different parameters, and even connect with the GP S system to track objects. 1.3 data exchange and management system When the radio frequency card enters the working area of ​​the transmitting antenna, an inductive current is generated, the radio frequency card obtains energy and is activated, and the radio frequency card sends its own coding and other information through the card to send out, and the receiving antenna of the system receives the radio frequency signal received from the radio frequency The carrier signal sent by the card is transmitted to the reader / writer through the regulator. The reader / writer demodulates and decodes the received signal and sends the signal to the background host system for processing. The main system determines the validity of the card according to the logic operation , For different settings to make the appropriate treatment and control, issue a command signal to control the actuator action. Radio frequency identification technology is the use of radio frequency signals and spatial coupling of transmission characteristics, to identify the object automatically identified. Radio frequency identification system by the reader (reader, reader, Reader), Tag (Tag) and data exchange and management system consists of three parts. Radio frequency identification technology is based on the principle that the reader generates a field of energy within a readable range to excite the electronic tag, and when the tagged food enters this distance range, the reader will be controlled to emit a microwave interrogation signal while After receiving the signal of the reader, the electronic tag combines the data of the signal and the tag to be reflected back to the reader, and the microwave synthesized signal reflected back carries the data information on the electronic tag. The reader receives the microwave reflected by the tag After the signal, the reader can read out the information stored in the tag after being processed by the microprocessor in the reader. 2 radio frequency identification technology in food applications With the enhancement of people's food safety awareness, the emphasis on food safety by the government departments and the exposure of the news media to the safety accidents have made food safety increasingly severe. Food is directly related to people's health. In addition to establishing a series of national standards and industry standards to standardize food processing, processing and marketing, high-tech means of food safety management are also required. Applying RFID technology to the food industry can effectively ensure the real-time performance and accuracy of information collection, improve the level of food safety and monitoring and control, coordinate all aspects of the food chain, increase people's understanding of food and ensure food safety Row. RFID technology in the food industry applications are mainly about the following aspects: 2.1 RFID technology in food security applications Due to the current imperfect legal system in our country and the non-standard market, some unscrupulous elements at home and abroad have faked huge profits and faked famous brand names, shoddy goods and fake real ones to form certain markets for counterfeit and shoddy goods, which have seriously disrupted social order and economic order, Fake food in the famous wine, health products, most of the famous specialty. Compared with other anti-counterfeiting technologies such as digital anti-counterfeiting technology and laser anti-counterfeit technology, RFID has the following advantages: Every label has a globally unique ID number, and can not be modified or imitated; no mechanical wear and antimagnetic Sexual, anti-fouling and waterproof; RFID readers have physical open not directly to the end user