What is RFID tag?

RFID wireless radio frequency identification is a non-contact automatic identification technology. It can automatically identify the target object and obtain relevant data through radio frequency signals. The identification work does not need manual intervention, and can work in a variety of harsh environments. RFID technology can identify high-speed moving objects and identify multiple electronic tags at the same time. It is fast and convenient to operate and frequently used in supermarkets. RFID tag: consists of coupling components and chips. Each RFID tag has a unique electronic code, which is attached to the object to identify the target object, commonly known as electronic tag or smart tag

RFID electronic tags: active tags, passive tags, semi active and semi passive tags.

Working principle of RFID: after the tag enters the magnetic field, it receives the RF signal sent by the interpreter, and sends the product information stored in the chip (Passive Tag, passive tag or passive tag) with the energy obtained by the induced current, or actively sends the signal of a certain frequency (Active Tag, active tag or active tag); After the information is read and decoded by the interpreter, it is sent to the central information system for relevant data processing.

Passive

Passive tags do not have an internal power supply. Its internal integrated circuit is driven by the electromagnetic waves received by the RFID reader. When the tag receives a signal of sufficient strength, it can send data to the reader. These data include not only the ID number (globally unique identification ID), but also the data pre-existing in the EEPROM in the tag.

The passive label has the advantages of low price, small size and no power supply. RFID tags in the market are mainly passive.

Semi active

Generally speaking, the antenna of the passive tag has two tasks: first, it receives the electromagnetic wave sent by the reader to drive the tag IC; Second: When the tag returns the signal, the impedance of the antenna needs to be switched to generate the change of 0 and 1. The problem is that if you want to have the best return efficiency, the antenna impedance must be designed in "open circuit and short circuit", so that the signal will be completely reflected and cannot be received by the tag IC. The semi-active tag is to solve this problem. The semi-active type is similar to the passive type, but it has a small battery, and the power can drive the label IC just to make it work. The advantage of this is that the antenna can be fully used as a return signal without caring about the task of receiving electromagnetic waves. Compared with passive type, semi-active type has faster reaction speed and better efficiency.

subject- verb form

Different from the passive and semi passive, the active tag itself has an internal power supply to supply the power required by the internal IC to generate external signals. Generally speaking, active tags have long read distance and large memory capacity, which can be used to store some additional messages sent by the reader.

Since the adhesive parts will be subject to various stress tests in actual use, we will conduct different tests in the laboratory to ensure the adhesive quality. The common practice is to test RFID tags made with production equipment. The positioning of the chip can be detected by the visual system, and the performance of the label can be tested by the card reading system.

In addition to the quick test methods provided by these production equipment, there are more detailed follow-up test methods to test the bonding quality.

Shear force of the chip: push the chip away from the substrate using the cutter of the shear force tester. In the shear test, the ideal value of adhesive force between adhesive, chip and substrate shall not be less than 25 N/mm2.

Curing degree of adhesive: DSC analysis (differential scanning calorimetry) can be used to detect whether the adhesive is completely cured within the selected parameter range. This test method can reflect the abnormal conditions caused by too short curing time or too low temperature.

Micrograph: The micrograph of the chip and substrate can show the extent to which the chip and its bumps are pressed into the antenna. Insufficient pressure will lead to poor contact of the chip, and excessive pressure will lead to damage of the chip or substrate.

Measuring the reading distance: In this test, keep the power of the card reader unchanged, and keep the label to be tested away from the card reader until the card reading error is prompted. Or, continuously increase the transmission power of the card reader until the tag starts to transmit data; In this case, the distance between the label and the card reader has been set in advance.

Short range RFID products are not afraid of oil stains, dust pollution and other harsh environments, and can replace barcode in such environments, such as tracking objects on the assembly line of the factory.

Long distance RFID products are mostly used in transportation, and the recognition distance can reach tens of meters, such as automatic toll collection or vehicle identification.

1. In the retail industry, the application of barcode technology has made the various links of tens of thousands of commodities such as types, prices, places of origin, batches, shelves, inventory and sales managed in an orderly manner

2. The automatic vehicle identification technology is adopted to avoid the phenomenon of vehicles queuing for customs clearance in toll places such as roads and bridges, parking lots, etc., and reduce the waste of time, thus greatly improving the efficiency of transportation and the capacity of transportation facilities

3. On the automated production line, all links of the entire product production process are under strict monitoring and management

4. In the harsh environment of dust, pollution, cold and hot, the application of remote radio frequency identification technology has improved the inconvenience of truck drivers having to get off to go through formalities

5. In the bus operation management, the automatic identification system accurately records the arrival and departure time of vehicles at each station along the line, providing real-time and reliable information for vehicle dispatching and the whole process operation management.

6. In the device management, the RFID automatic identification system can bind the specific location of the device with the RFID reader, and record the process when the device moves out of the designated reader location.

RFID electronic tag technology is widely used, with typical applications: animal chips, access control, air parcel identification, document tracking management, parcel tracking and identification, animal husbandry, logistics management, mobile commerce, product anti-counterfeiting, movement timing, ticket management, car chip anti-theft device, parking lot control, production line automation, material management, etc.

RFID is the abbreviation of Radio Frequency Identification, which is translated into electronic tag in Chinese, also known as Radio Frequency Identification technology. With the continuous progress of society, the continuous development of science and technology, and the accelerated pace of life, people require simple and fast methods in more aspects of life, and electronic tags came into being. Nowadays, electronic tags have been widely used in modern people's daily life.

In many big cities, you can easily transfer between different lines by taking rail transit by purchasing a single ticket with an electronic tag at a time; To borrow books in the library, you don't need to go through the borrowing procedures with the librarian, but just enter the password in the automatic borrowing and returning system, and then easily borrow the books you want; In many hypermarkets and supermarkets, RFID tags can effectively prevent people from taking away goods without payment. In hospitals, electronic tags are widely used. For example, newborn babies are very similar in appearance, which is easy to cause the misunderstanding of recognizing the wrong baby. On TV, it is still common for nurses or parents in hospitals to hold the wrong child decades ago, leading to a lot of family tragedies, so they can accurately identify their identity and avoid mistakes. In addition, there is an electronic medical record, through which doctors and nurses can clearly know the medication of patients during ward rounds. In this way, not only the work of the medical staff will be orderly, but also the medical personnel and their families can avoid a lot of trouble.

The wide application of RFID tags has brought a lot of convenience to people's lives. I believe that in the near future, it will be applied to more and more useful places. At that time, our life will be better, and people can save a lot of time to do more meaningful things

Solution of RFID tag in elevator inspection certificate

The emergence of RFID electronic tags has solved the problem of the special equipment inspection department of the Bureau of Technical Supervision. RFID paper tickets are embedded with electronic certificates, which are characterized by direct surface printing, strong anti-counterfeiting ability, reliable ticket checking and accurate background statistics. Paper RFID tags are not only cheap, but also can store information, which can be recorded in the chip. The special equipment inspection department of the Technical Supervision Bureau can know whether the maintenance company has carried out routine inspection according to regulations by extracting information, and also know the specific inspection time and the qualification certificate of the inspection personnel responsible for the elevator maintenance company.

Application of RFID tags in medical field in Pittsburgh, USA

Researchers at the University of Pittsburgh have developed an orthopaedic tag system, which attaches RFID tags embedded with sensors to orthopaedic instruments, so that the tags implanted in the human body can track the use of the equipment in the body. The signal from the label inside the human body is transmitted to the reader outside the skin through the skin tissue. The system can not only track the implantation environment of human body, but also has a certain anti-counterfeiting property for orthopedic instruments.

Scheme of RFID tag baggage tracking system at Hong Kong International Airport

The RFID tag system enables the baggage handling system of the Hong Kong Airport Authority to track baggage more accurately, help the baggage to be delivered in time, and help the airport's flights and passengers to depart on time. It also helps improve baggage delivery and customer service.

RFID tag (anti disassembly wrist strap) personnel positioning plan of Beijing Women's Reeducation through Labor Institute

The CY-TZB anti disassembly wrist strap with 2.45GHz microwave is used, and RFID technology and ZigBee networking technology are used to locate prisoners, so as to effectively monitor and manage their daily behaviors, prevent prisoners from escaping from prison and cause serious social problems.

Open source projects for RFID research:

Open source software radio technology has a profound impact on the radio industry, and RFID is no exception. GNU Radio is a free suite of software development tools. It provides signal operation and processing modules, with which software defined radios can be implemented on easily made low-cost RF hardware and general-purpose microprocessors. This suite is widely used by amateurs, academic institutions and commercial institutions to research and build wireless communication systems. GNU Radio applications are mainly written in Python programming language. But its core signal processing module is built on the microprocessor with floating point operation by C++. Therefore, developers can simply and quickly build a real-time, high-capacity wireless communication system. Although its main function is not an emulator, GNU Radio supports the research of signal processing algorithms for pre stored and (signal generator) generated data without RF hardware components.

RFID tags shall be used for identification of secret documents

First of all, RFID tags can be printed between sheets of paper, which is difficult to see at first glance. If someone tries to tamper with the label, the file will also be damaged.

Second, tags can be encrypted and locked so that only recipients can read them.

In addition, the cost of RFID tags is low. Ensure the high security of packaging, contracts, official plans or any other important documents.

Users can put their secret documents under an RFID display to check the RFID tags contained in the documents. In less than a second, the smart display can connect to the cloud and authenticate the file. All that is needed is software, optics and computers. In the near future, users may be able to use mobile phones, laptops and mobile devices to check RFID tags.

RFID tag antenna is a transponder antenna of RFID electronic tag and a communication induction antenna. Generally, a complete RFID tag transponder is composed of chips. At present, RFID tag antenna is divided into metal etching antenna, printed antenna and copper plated antenna due to different materials and manufacturing processes.

Printed antennas used to be popular, but they were gradually eliminated from the market due to the unreliable consistency of the electrical properties of the finished products and the service life. Although printed antenna has the advantage of short production cycle. In recent years, with the development of nanotechnology, nano silver paste antenna has emerged. However, due to the reliability problem, the market has not been opened for a long time.