HF RFID Tag
HF RFID Tag is a radio frequency technology used to track items and communicate with sensors. It can also be read by most smartphones with near field communication (NFC) capability.
Unlike other RFID technologies, HF tags are not sensitive to metals and liquids. This makes them more suitable for use in harsh environments.
Inductive Coupling Technology
HF RFID systems use inductive coupling to power and communicate with the tags. The electromagnetic wave from the interrogator antenna is coupled to the tag via its coil and reflected back into the interrogator antenna connection, with the energy being used to activate the chip inside the tag. The chip then transmits its ID code back to the interrogator, which translates it into a message that identifies the object or item.
The magnetic field from the RFID interrogator is omnidirectional, so it covers a wide area with its intensity. However, within a radius of the near-field (the region around the antenna where magnetic flux is strong enough to affect objects), the energy received at the transponder decreases rapidly as 1/d2. As the distance between the interrogator and tag increases, the amount of energy received at the tag drops even more.
To overcome these problems, Alonso-Gonzalez et al. designed a double CF-based HF RFID card with a coil and module in one package. This design reduces manufacturing costs, increases the transferred voltage, and enhances performance compared to standalone modules. The authors analyze the operation of this design from first principles and show that it achieves better transfer efficiency and more bandwidth compared to single-layer modules. The results are supported by HFSS simulations, circuit simulations and experimental measurements. The paper also describes the fabrication process and tests the card’s reliability.
Passive Tags
Passive tags have no battery and wait for energy from a RFID reader to transmit a signal, which is detected by the tag’s antenna. When a signal is received, the UHF RFID Tag microchip inside the RFID tag broadcasts a response, also known as backscatter. This change in electromagnetic or RF waves is then read by the RFID tag’s antenna and the data transmitted to the reader.
RAIN RFID tags are used in a variety of different applications, including item-level tracking, retail inventory and tracing, warehouse, 3PL, gate controls, and anti-counterfeiting. They are available in many form factors, and can be easily embedded into a number of surfaces or devices.
InfoChip’s HF RFID Tags are designed to be durable and rugged, for use in tough environments. These include the ChainSlingTag and DataBandMicro+, which are affixed to cylindrical objects like hose, pipe, frac iron, lifting shackles, canisters and more. They are also NFC-compatible and can be scanned with mobile phones for identification and tracking purposes.
Beacons are another common type of HF RFID tag and are often used in real-time location systems (RTLS) to track assets in continuous transmission mode. Beacons are powered by the radio signal from the RTLS UHF RFID Tag reader and emit signals at pre-set intervals, which is then communicated to the RTLS antenna system to track the assets in real time.
Active Tags
Unlike passive tags, active RFID tags are equipped with an internal battery to power the tag’s microprocessor and transmit data. Like LF tags, they receive power from the reader antenna electromagnetically, but then use an onboard transmitter to send their own signal back to the interrogator, known as “backscatter”. These signals may be periodically broadcast or only transmitted when a reader is within range. This is called “active mode”.
HF systems operate at 3 MHz to 30 MHz and provide reading distances of 10 cm to 1 m. They are ideal for tracking items over a large area, such as in a container yard, and can support other types of applications, including electronic ticketing and payment transfer and smart card technology. Near Field Communication (NFC) technology, which is based on HF RFID, is used for common applications such as hotel key cards.
Active RFID tags are encased in rugged, durable exteriors to protect the onboard battery and circuitry from extreme environmental conditions. Some, such as InfoChip’s durable ChainSlingTag, also feature visual information and a unique ID for inspection and tracking of cylindrical objects like hose, pipe, frac iron, lifting shackles and canisters with diameters ranging from 0.5” to 24”. Some active tags are designed to have on-board sensors to track moisture levels, temperature or other parameters that provide data on the condition of the item.
Labels
A smart label is an identifier with memory support able to exchange radio frequency data with RFID controllers. Labels, supplied in rolls, can be printed and encoded using RFID printers, with a wide range of variables and possibilities of choice / customization (frequencies, chips, formats, sizes, materials, prints and codings).
Low-frequency (LF) tags have slower read rates than UHF and HF but are less prone to interference from metals and liquids, making them well suited for affixing to items such as beer kegs or cars. These tags are also used for item-level inventory management, library media cataloging and to track bracelets for theme park visitors.
High-frequency (HF) ISO 14443 tags have security features such as encryption and short read ranges, which makes them ideal for embedding into smart cards and high-security payments solutions, as well as for access control applications. ISO 15693 tags have lower manufacturing costs than HF ISO 14443 and good functioning with metals and liquids, which makes them a popular choice for item-level logistics, retail and item-level tracking, CD & DVD tagging and pharmaceutical item tracking.
Ultra-high frequency (UHF) tags have a frequency range between 860 and 960 MHz. These tags are commonly known as “supply chain frequency” because they work within the supply chain GS1 EPC standards and national/regional frequencies regulations, but still provide good read ranges and rates for tracking items in retail inventory and driving supply chain efficiencies.