UHF RFID is an acronym mouthful. UHF stands for ultrahigh frequency, while RFID stands for radio frequency identification. In some instances, this technology is replacing barcodes as a method of managing warehouse inventory and the supply chain. RFID tags are placed on each object and UHF radio frequencies read the stored data. A UHF RFID tag allows stock to be managed and tracked without an employee manually scanning each item.
UHF is a large radio band that ranges from 300 MHz to 3 GHz. Cell phones, pagers and satellite communications use this band, because it can be broken up into numerous sub-bands. The distance the tag is able to transmit depends on the UHF sub-band used, with lower frequencies having shorter ranges. The UHF RFID tag may use sub-bands that provide a range as small as 6 feet (1.8 meters).
UHF RFID requires three components: a transponder, an antenna and a transceiver. The transponder, or tag, contains data and is attached to the item. The antenna transmits the UHF radio signal to the transponder, powering and activating it. The activated transponder then transmits the data stored on the tag back to the transceiver. Data such as who is in possession of an item, where the item is during shipment and the location of an item in a warehouse can all be read from the RFID tag.
The UHF RFID tag has numerous benefits over the more common barcode. The tag can hold much more data and, unlike a barcode, data can be added, updated or changed. While a barcoded item needs to be oriented so the barcode faces outward, the RFID tag does not have to be visible. Printed barcodes are also susceptible to wearing or weathering during shipment. A UHF RFID tag can be placed inside the packaging for protection.
There are two types of UHF RFID tags, active and passive. Active RFIDs have a battery, allowing them to be self-powered and store a large amount of data. Governments use these active tags to audit shipments because they cannot be erased. Passive RFIDs are the most widely used and the typical tag can store between 8 kilobytes (kB) and 32 kB of data. Passive tags can be erased, allowing data to be rewritten and the tag reused.
One drawback is that UHF RFID tags rely on radio waves, and some material can cause radio interference. Factories with steel frameworks, metallic products or liquids may be a challenge for RFID. Barcodes may be a more reliable option for managing these types of products in the supply chain.
Security and privacy may also be an issue with the UHF RFID tag. The information on the tags is generally not encrypted and the radio waves are easily received. It may be possible for a hacker to collect information from tags simply by standing near a loading dock. Private information such as a customer's name or special pricing can be picked up and exploited.