UHF RFID: Precise Detection, Long Range

RFID stands for “Radio-Frequency Identification” – a generic term for contactless identification systems using radio waves. In RFID, a reader communicates with a transponder (tag) attached to an object. RFID is categorized into three main frequency ranges:

• LF RFID (Low Frequency, approx. 125–134 kHz)
• HF RFID (High Frequency, 13.56 MHz)
• UHF RFID (Ultra High Frequency, 860–960 MHz)

What all have in common: They allow the reading of IDs without line-of-sight. However, the design, range, transmission method, and application scenarios vary significantly.

UHF RFID operates in the 860 to 960 MHz frequency band and uses the standardized EPC Gen2 protocol (ISO/IEC 18000-63). Unlike LF and HF systems, UHF RFID is based on the backscatter method: Tags do not actively transmit, but instead reflect the signal from the reader and modulate it with their data. This form of communication is energy-efficient and enables long read ranges and rapid bulk reading.

UHF RFID tags consist of a microchip and an antenna. The chip stores unique identifiers and optionally additional data or sensor values. This technology is particularly suitable for logistics processes, industrial applications, container management, or track & trace.

• LF RFID: a few centimeters (e.g., access control, animal tagging)
• HF RFID: up to approx. 1 meter (e.g., contactless payment, libraries)
• UHF RFID: several meters (3–10 m or more, depending on environment and antenna technology)

The greater range of UHF RFID enables automated reading over longer distances, such as at goods-in stations or in warehouses – without manual scanning.

UHF RFID tags are available in different types:

• Passive tags operate entirely without a battery.
• Semi-passive tags include a battery for sensors but still use backscatter for communication.
• Active tags actively transmit signals and can reach ranges of several dozen meters, but differ technically from traditional UHF RFID.

Although LF, HF, and UHF use different frequencies and physical principles, they all belong to the same family: They transmit a digital identity wirelessly – contactless, unique, and reliable. The term “RFID” therefore does not refer to a single technology, but to a broader concept with various implementations. Only UHF RFID uses the reflective backscatter method – LF and HF (often referred to as Near Field RFID) communicate via inductive coupling.

The right system always depends on the specific use case, environment, and requirements for read range, speed, and media compatibility.

UHF RFID is now well established and standardized across many industries. The technology is particularly widespread in logistics (shipping, goods receipt, returns), retail (inventory, self-checkout, theft prevention), industry (tool tracking, series production, traceability), healthcare (medications, instruments, textiles), and aviation (maintenance, spare parts, baggage tracking).

The availability of robust, low-cost hardware components – from readers to specialized tags – enables flexible and scalable solutions. In addition to classic gate readers and handheld scanners, there is increasing use of wireless readers with Wi-Fi, Bluetooth, or cellular connectivity. Edge AI capabilities on readers allow local data preprocessing, such as filtering out false reads, triggering events, or detecting movement patterns in real time.

Furthermore, the clear separation of TID (fixed IC serial number), EPC (electronic product code), and user memory (freely writable memory area) allows for flexible data organization.

Modern UHF RFID systems are increasingly used as data interfaces – not only for identification but also for transmitting environmental data. Tags with integrated sensors measure temperature, shock, or humidity along the supply chain – either fully passive or battery-assisted. These values are automatically transferred during the readout process.

Physical integration also makes a difference: tags must be chosen according to the surface, environment, and application. Options include washable textile tags, metal-mount tags, miniaturized versions for medical devices, or durable hard tags for industrial use. The reader infrastructure is just as diverse – stationary, mobile, or machine-embedded.

In complex environments, RFID shielding is crucial. To avoid unintended reads, targeted shielding measures are used – such as metalized boxes, reading tunnels, or absorber materials. This allows for precise definition of read zones.

The term RAIN RFID refers to a global initiative based on UHF RFID using the EPC Gen2 standard. It connects every RFID tag to a cloud-based system – enabling applications such as digital twins, serial number management, or traceability. RAIN is especially widespread in retail and logistics, as it combines high read speeds with cross-system data availability. 

UHF RFID is capable of more than just ID transmission – it can also be used for Real-Time Location Systems (RTLS). By analyzing antenna arrangements, signal strength (RSSI), or phase data, it’s possible to capture zone or movement data.

When combined with UWB (Ultra-Wideband), hybrid systems emerge where UHF provides the identity and UWB provides the location – an ideal solution for industrial, clinical, or warehouse environments. 

Near Field UHF is a variant of UHF RFID with a very short read range – typically under ten centimeters. Unlike HF RFID at 13.56 MHz, Near Field UHF also uses the backscatter principle, but with specially tuned antennas designed for magnetic coupling in the near field.

The advantage: selective reading on metal surfaces or in high tag-density environments – without unintended long-range reads. In contrast, HF RFID is well established globally in consumer-facing applications – such as payment systems or access cards – and is compatible with smartphones. Near Field UHF, however, is clearly targeted at industrial use cases.

A growing trend is dual-frequency tags, which can be read by both UHF readers and smartphones via NFC. They bridge industrial processes with point-of-sale interactions or consumer engagement.

A key application is the Digital Product Passport (DPP): A single tag stores a unique serial number, along with data on origin, material composition, carbon footprint, and recyclability – readable during logistics and visible to consumers. RFID thus becomes part of the circular economy.

Think WIOT highlights the technological implementation and real-world examples of the DPP in an interview series with leading hardware and solution providers.

UHF RFID is entering mobile devices. The first smartphones and external modules now enable UHF tag reading over several meters – functionality previously reserved for specialized readers.
This opens new fields of application: mobile inventories, product tracking in retail, or flexible logistics processes.

While the integration is still in its early stages, the potential is huge: UHF in smartphones makes the technology more mobile, accessible – and ready for a decentralized IoT.

Think WIOT is following this development in an interview series featuring leading vendors of UHF-capable smartphones and modules.