The application of the hottest RFID in the field o

1.1 system composition

a basic RFID system is generally composed of a chip that stores identifier information, that is, an electronic tag (tag), a reader used to write and read tag data (reader, also known as reading head), and an antenna. In order to realize the processing of label data, corresponding computer system support is also required

(1) tag (radio frequency card): it is the core component of RFID. It is installed on the identified object and stores electronic data in a certain format, that is, the detailed information about the object. Labels are similar to bar code symbols in bar code technology, but the difference is that they must be able to automatically or semi automatically transmit the stored information. Electronic tag is composed of tag antenna and tag chip. The tag chip is a monolithic system (s0c) with wireless transceiver and storage functions, in which the encoded data in the agreed format is stored to uniquely identify the attached object. It is the data carrier of RFID system and has the ability of intelligent reading and writing and encrypted communication

(2) reader: it can automatically read the electronic data stored in the electronic tag in a contactless way. It is the information control and processing center of RFID system. There is a communication protocol between readers and electronic tags, which transmits information to each other. Whenever an object attached with an electronic tag passes through its reading range, it emits radio waves to the tag, and then the tag sends back its stored object information. The whole process is non-contact

(3) antenna: transmit RF signals between electronic tags and readers. The antenna connected to the reader is usually made into a door frame and placed at the entrance and exit of the tested object. On the one hand, it can not completely adapt to the actual needs of passive electrons. The tag transmits radio signals to provide electric energy to activate the electronic tag; On the other hand, it also receives the information sent from the electronic tag. Each electronic tag also has its own micro antenna, which is used to communicate with the reader

1.2 working principle of RFID system

see Figure 1 for the schematic diagram of working principle of RFID system. Usually, the electronic tag is placed on the object, and the reader sends a certain frequency of RF signal through the antenna; When the electronic tag enters the radio wave receiving coverage of the reader, its micro antenna generates induced current, and the energy obtained by the electronic tag is activated and sends information such as data required for identification to the reader (the electronic tag demodulates instructions from the received radio frequency pulse and sends them to the control logic, which receives instructions to complete storage, sending data or other operations); The reader receives the carrier signal from the electronic tag, demodulates and decodes the signal under the strong guidance of the raw material industry department, and then sends it to the computer host for processing; The computer system judges the legitimacy of the label according to logical operation, makes corresponding processing and control for different settings, and sends command signals

2 advantages of RFID

rfid has the following advantages:

(1) easy to read

data reading is free of "contact", without light source, and can even be carried out through outer packaging. The effective recognition distance is large. When using the active label with its own battery, the effective recognition distance can reach more than 30 meters

(2) fast recognition speed

as soon as the electronic tag enters the recognition place, the reader can read the information in it instantly, and can process multiple electronic tags at the same time to realize batch recognition

(3) it is easy to realize miniaturization and is mostly a basic sample shape for the study of artificial organs and medical devices.

electronic labels are not limited by size and shape in reading. It is small, easy to package, and has various shapes (such as card shape, ring shape, button shape, pen shape, etc.), which can be hidden or embedded in most materials or products, making the marked goods more beautiful. It can be used in different occasions and is very convenient to use

(4) large memory capacity of data

generally, the two-dimensional barcode (PDF417) with the largest data capacity can only store 2725 numbers at most. If it contains letters, the storage capacity will be less, and the electronic label can be expanded according to the needs of users. At present, the electronic label chip produced on the market also has the lowest data storage capacity of 17 binary digits, which is far greater than the data volume of bar code. In the future, items need to carry more and more information, and the data capacity will expand with the development of memory specifications. For this, electronic labels will not be limited

(5) penetrability

rfid can read labels through non-metallic materials such as mud, dirt, paint, oil, wood, cement, plastic, water and steam during identification, without having to be in direct contact with the carrier of electronic labels. Data transmission uses a higher frequency band and uses the radio principle to transmit signals. Even when the electronic tag is wrapped with paper, wood, plastic, etc., it can still carry out penetrating communication

(6) environmental resistance

rfid can also read data in a dark or dirty environment. It has strong stain resistance to water, oil, drugs and other substances, unlike paper, which cannot be seen once it is dirty, and can be used even in harsh environments. The working temperature can reach -25 ℃ ~ +70 ℃, so electronic labels become an ideal choice for reading in dirty, humid and harsh environments

(7) long service life and wide application range

the service life of electronic labels can be more than 10 years, read and write 100000 times, without mechanical wear and failure

(8) better security

the number of electronic labels is unique, which can set password protection for the reading and writing of stored data, and can also add anti-counterfeiting identification code through an encryption operation. As long as it is scanned by Lianhe or the manufacturer's anti-theft identification equipment such as reader, the authenticity of the product can be immediately distinguished, with higher security

(9) cost

the price of electronic labels will decrease with the development of technology and the expansion of production scale

3 application of RFID in commodity anti-counterfeiting

the principle of anti-counterfeiting is: write the commodity identification number (ID), that is, the anti-counterfeiting code (which is encrypted by hardware or software algorithm), in the RFID chip, and this ID is unique in all links such as production and sales; The chip is made into an electronic label, which is attached to the commodity, making it an integral part of the commodity. When the electronic label is "forced" to be separated from the commodity, the "integrity" of the commodity is destroyed, and the commodity is considered to have been "consumed", and the anti-counterfeiting ends. In the above links, various technical means are used to ensure that the ID verification process can not be forged and tampered with. If the verification mechanism is forged, counterfeit goods will appear; If the verification process is tampered with, the authenticity will be "falsified" and the market will be disturbed. In this way, in the whole process of commodity production, circulation and consumption, there is only one commodity with unique ID and unique verification means, so as to achieve the purpose of anti-counterfeiting. The identification ID data of RFID electronic tag is read-only and cannot be changed. In order to prevent counterfeiters from using forged electronic tags with the same ID, a unique secret information "key" associated with the ID can also be written in the anti-counterfeiting tag to identify the uniqueness of the verification process. Therefore, the unique anti-counterfeiting tag ID, the unique secret verification information in the chip and the strict encryption authentication mechanism can make the anti-counterfeiting technology effective for a long time

the emergence of fake and shoddy commodities in the market of some famous brands commonly used by domestic people, such as alcohol, cosmetics, medical and health products, will seriously affect the reputation of these famous brand commodities and the economic construction of the country, so its anti-counterfeiting is very necessary. RFID anti-counterfeiting technology breaks through the idea of previous anti-counterfeiting technology and takes a new measure, which makes it difficult to forge, easy to identify, information feedback, password uniqueness, password confidentiality, one-time use and other characteristics. Compared with laser anti-counterfeiting and digital anti-counterfeiting, RFID technology has the following advantages: each tag has a unique ID number, which is placed in ROM when making chips, which cannot be modified and difficult to copy; No mechanical wear and dirt; The reader has a physical interface that is not directly open to end users to ensure its own security; In terms of data security, in addition to the password protection of electronic labels, some algorithms can be used to realize the security management of the data part; There is a process of mutual authentication between readers and electronic tags

4 conclusion

no matter how RFID anti-counterfeiting is used, it is also necessary to ensure the safety of identification instruments. Only in this way can it really play an anti-counterfeiting role. At present, RFID is mainly used in logistics management, medical field, monitoring and tracking management of goods and dangerous goods, baggage consignment of civil aviation and non-stop charging of roads and bridges. It can be predicted that the application of RFID will breed a huge market and a new economic growth point. Its potential and prospect will be very attractive. The unique advantages of RFID technology will form a huge industry in the world, which is worthy of attention in various fields

reprinted from: computer and information technology