The application of the hottest RFID technology in

  • Detail

The application of RFID (radio frequency identification technology) in carton packaging (Part 1)

the application of radio frequency technology in other industries has become increasingly mature, and its application in the carton industry is still in its infancy. In the business information in October, we introduced the application of radio frequency technology in base paper management, which has attracted the attention of many readers. In response to readers' requirements, this issue of the magazine gives a more comprehensive and complete introduction to radio frequency identification technology

it is reported that Wal Mart, the world's retail giant, announced that it should first check whether the packaging box is in good condition from 2005. From March, Wal Mart will let its top 100 major suppliers put electronic labels in their goods. Wal Mart supermarket will use RFID technology in the goods supply chain. Taiwan yongfengyu Group actively develops RFID technology and strives to become the first choice for the carton packaging of Wal Mart's Asian products. Therefore, the application of RFID technology in carton packaging is bound to develop rapidly. Now let's introduce RFID (radio frequency identification) technology, hoping to help you

rfid (radio frequency identification technology)

radio frequency identification technology, in English is radio frequency identification, which is called RFID for short

RFID system is generally composed of three parts, including electronic tags, readers and antennas. Specific applications also include related computer and software information processing systems

electronic tag, whose English name is tag (i.e. RF card): it is composed of coupling elements and chips. The tag contains a built-in antenna, which is used to communicate with the RF antenna

reader, English name is Reader: a device that reads (can also be written in the read-write card) label information

antenna: transmit RF signals between the tag and the reader. The working principle of RFID (radio frequency identification technology) is: when the electronic tag enters the magnetic field area, the received reader sends a signal, and with the energy obtained by the induced current, it sends out the product information stored in the chip (passive tag, no power label or passive label), Or actively send a signal of a certain frequency (active tag, with power label or active label); The reader reads and decodes the information, and then sends it to the central information system for relevant processing, but in practical applications, it needs other software and hardware support

RFID technology can be divided into two categories: low-frequency system and high-frequency system according to the different frequencies it uses; According to whether there is a battery in the electronic tag to supply power, it can be divided into active system and passive system; From the way of information injection stored in electronic labels, they can be divided into three categories: integrated circuit solidification type, on-site wired rewriting type and on-site wireless rewriting type; According to the technical means of reading electronic tag data, it can be divided into three categories: broadcast transmission type, frequency doubling type and reflection modulation type

low frequency system generally refers to its working frequency less than 30MHz. Typical working frequencies include 125kHz, 225khz, 13.56M, etc. RFID systems based on these frequency points generally have corresponding international standards. Its basic characteristics are that the cost of electronic labels is low, the amount of data stored in the labels is small, the reading distance is short (passive, the typical reading distance is 10cm), the shapes of electronic labels are diverse (card, ring, button, pen), and the directivity of reading antennas is not strong

high frequency system generally refers to its working frequency greater than 400MHz. Typical working frequency bands include 915MHz, 2450MHz, 5800mhz, etc. High frequency systems are also supported by numerous international standards in these frequency bands. The basic characteristics of the high-frequency system are that the cost of the electronic tag and reader is high, the amount of data stored in the tag is large, the reading distance is far (up to a few meters to more than ten meters), the high-speed movement performance of the object is good, the shape is generally card shaped, and the reading antenna and the electronic tag antenna have strong directivity

the battery is installed in the active electronic tag, which generally has a long reading distance. The disadvantage is the limited service life of the battery (3 ~ 10 years)

there is no battery in the passive electronic tag. When its own laboratory introduces the standard method into its own detection work, it receives the microwave signal sent by the reader (readout device), and converts part of the microwave energy into DC for its own work. Generally, it can be maintenance free. Compared with active systems, passive systems have some limitations in reading distance and adapting to the speed of objects

the information in the integrated solidified electronic label is usually injected in the ROM process mode during the production of integrated circuits. The information saved in the integrated solidified electronic label is the same as that in the field wired rewritten electronic label. Generally, the information saved in the electronic label is written into its internal E2PROM storage area. When rewriting, a special programmer or writer is required, and power must be supplied during the rewriting process; The on-site wireless rewriting electronic tag is generally applicable to the active electronic tag, with specific rewriting instructions, and the information stored in the electronic tag is also located in the E2PROM storage area. Generally, the time required to rewrite the electronic tag data is much longer than that required to read the electronic tag data. Generally, the time required for rewriting is in seconds, and the reading time is in fact in milliseconds

radio frequency identification system is the simplest to implement. The electronic tag must work in an active way and broadcast its stored identification information to the outside in real time. The reader is equivalent to a receiver that only receives but not sends. The disadvantage of this system is that the electronic tag has to constantly transmit information, which not only consumes electricity, but also causes electromagnetic pollution to the environment, and the system does not have security and confidentiality

frequency doubling RFID system is difficult to realize. Generally, the reader sends out the RF inquiry signal, and the signal carrier frequency returned by the electronic tag is the double frequency of the RF sent by the reader. This working mode provides convenience for the reader to receive and process echo signals, but for passive electronic tags, when the electronic tag converts the received RF energy of the reader into the frequency doubled echo carrier frequency, its energy conversion efficiency is low, and improving the conversion efficiency requires higher microwave skills, which means higher cost of electronic tags. At the same time, the operation of this system must occupy two working frequency points, which is generally difficult to obtain the product application license of the radio frequency management committee

the realization of reflection modulation RFID system should solve the problem of receiving and transmitting at the same frequency. When the system works, the reader sends out a microwave inquiry (energy) signal, and the electronic tag (passive) rectifies part of the received microwave inquiry energy signal into direct current for the circuit in the electronic tag to work, and the other part of the microwave energy signal is modulated (ask) by the data information stored in the electronic tag and then reflected back to the reader. After receiving the reflected amplitude modulation signal, the reader will decode the identifying data information stored in the electronic tag. In the working process of the system, the reader sends out the microwave signal and receives the reflected amplitude modulation signal at the same time. The strength of the reflected signal is much weaker than that of the transmitted signal, so the difficulty in technical implementation lies in the same frequency reception

Copyright © 2011 JIN SHI