Background & Application
RFID technology is an automatic identification technology based on wireless signals and is suitable for a variety of application scenarios. It is receiving more and more attention in libraries, document and archive management. By adding RFID labels to books, documents and archives, functions such as automatic reading, query, retrieval and return can be realized, improving the management efficiency and service level of literature materials.
There are two main types of RFID labels used in libraries and archive document management, RFID HF labels and RFID UHF labels. These two labels have different characteristics. Let me analyze their differences below:
RFID technology can be divided into several types according to different operating frequencies: low frequency (LF), high frequency (HF), ultra high frequency (UHF) and microwave (MW). Among them, high frequency and ultra-high frequency are the two most widely used RFID technologies at present. They each have their own advantages and limitations, and have different applicability in different scenarios.
Working principle: High-frequency RFID technology uses the principle of near-field inductive coupling, that is, the reader transmits energy and exchanges data with the tag through a magnetic field. UHF RFID technology uses the principle of far-field electromagnetic radiation, that is, the reader transmits energy and exchanges data with the tag through electromagnetic waves.
Product selection analysis
1. Chips: HF recommends using NXP ICODE SLIX chip, which complies with the protocols ISO15693 and ISO/IEC 18000-3 Mode 1. It has a large EPC memory of 1024 bits, can rewrite data 100,000 times, and can save data for more than 10 years.
UHF recommends using NXP UCODE 8, Alien Higgs 4, compliant with the protocols ISO 18000-6C and EPC C1 Gen2, EPC, 128 bit user memory, which can re-write data 100,000 times, and the data can be saved for more than 10 years.
2. Antennas: HF antennas are relatively slender, which reduces the interference effect of multi-tag stacking. Electromagnetic waves can transfer some energy to the tags behind them through the antenna. They are ultra-thin in appearance, low in cost, excellent in performance, and highly concealable. Therefore, HF labels suitable for the management of books and archive boxes. However, in single-page file management, it is mainly used for highly confidential files, such as top-secret documents, important personnel files, design drawings, and confidential documents. There are only one or a few pages in these portfolios. Using HF tags will overlap closely, causing mutual interference, affecting the recognition accuracy, and failing to meet management requirements. In this case, it is recommended to use the UHF labeling solution.
3. Surface material: Both HF and UHF can use art paper as the surface material, and can print customized text, patterns or barcodes. If you don't need to print, you can use wet inlay directly.
4. Glue: The application scenario of tags is usually affixed to paper. It is easy to stick and the usage environment is not harsh. Low-cost hot melt adhesive or water glue can usually be used.
5. Release paper: Generally, glassine-backed paper with a silicone oil layer is used, which is non-adhesive and makes it easy to tear off the tag.
6. Reading range: HF RFID technology is a near-field inductive coupling technology, and its working range is small, generally within 10 centimeters. UHF RFID technology is a far-field electromagnetic radiation technology. The electromagnetic wave has a certain degree of penetration and its working range is large, generally more than 1 meter. The reading distance of HF is small, so it can accurately locate books or archive files.
7. Reading speed: Due to the limitation of near-field inductive coupling principle, HF RFID technology has a slow reading speed and it is difficult to read multiple tags at the same time. Due to the advantages of far-field electromagnetic radiation principle, UHF RFID technology has a faster reading speed and a group reading function. UHF technology has a longer reading distance and faster reading speed, so it will be more efficient when inventorying books or files.
8. Anti-interference ability: The near-field inductive coupling of high-frequency RFID technology reduces potential wireless interference, making high-frequency technology extremely "immune" to environmental noise and electromagnetic interference (EMI), so it has strong anti-interference ability. . UHF uses the principle of electromagnetic emission, so it is more susceptible to electromagnetic interference. At the same time, metal will reflect signals and water can absorb signals. These factors will interfere with the normal function of the label Although some UHF stickers after technological improvements have excellent performance in preventing interference from metals and liquids, compared with high-frequency labels, UHF is still slightly inferior, and other methods need to be used to make up for it.
9. The use of RFID labels in conjunction with door-shaped channels and systems can effectively prevent books and files from being lost and implement illegal removal alarm functions.
HF and UHF RFID solutions each have their own advantages and disadvantages, and the selection should be weighed and compared based on specific needs and conditions.
