The What and Why of RFID

April 16, 2020

Radio-frequency identification (RFID) is a technology that uses radio waves to read data encoded on RFID tags or smart labels. This works similarly to barcode scanning, however, RFID tags don’t have to be scanned at line-of-sight, allowing for a hands-free approach. This means entire pallets or truckloads of products can be scanned at once.

RFID systems have three components: RFID tag, RFID reader and antenna. The RFID tag contains an integrated circuit with encoded information, and the antenna transmits the information to the RFID reader. The reader converts the radio waves from the antenna into a digital format. The collected data can then be transferred to a database for storage or analyzation.

RFID Tags and Smart Labels

RFID tags can be passive or active. Passive tags only transmit data when activated by the RFID reader. They are smaller and less expensive than active tags, which contain batteries that enable them to continuously transmit data and at further distances. Semi-passive tags also contain a battery, but not for data transmission. These tags have additional features like sensors for environmental monitoring or sound notifications. RFID tags also come in a variety of frequency ranges: low, high and ultra-high frequency (UHF). UHF tags are commonly used in the supply chain.

RFID Tags can be “read-only” or “read-write.” Read-only tags only transmit data. Read-write tags contain additional space where data can be added. These are useful in applications such as asset tracking or supply chain logistics where the location of an item can be updated as it travels.

Smart labels use RFID and barcode technology, usually printed as a paper label and readable by both RFID and barcode readers. This application is useful in postal and retail services as scanning can still be done by hand when necessary. Smart cards are a similar passive technology in card form, such as chip-containing credit cards and access cards to buildings or computer networks.

History of RFID

Radar technology was developed during the 1930s. Throughout the decades, radio frequency technology applications evolved. In the 1960s, Electronic Article Surveillance was created where an electronic tag is placed on an item (such as an article of clothing) and remains active until passed across a deactivator – the system commonly used in retail to prevent shoplifting.

A patent was obtained for a passive RFID tag in 1973 in the form of a card reader, like those used in hotels to let visitors enter rooms. Another patent was obtained that same year for the first Radio Frequency Identification Transponder system. RFID is thought of as being officially invented in 1983 by Charles Walton who received the first patent with the word “RFID.”

Slowly, the use of RFID grew. In 1999, Kevin Ashton coined the term “Internet of Things” while explaining the potential of RFID technology.

One area where RFID technology is gaining use is luggage tracking for airlines. The technology saves time and reduces errors involved in manual scanning, resulting in fewer pieces of lost luggage and higher customer satisfaction. RFID technology sees use primarily in inventory management, supply chain logistics and asset tracking. In 2005, the Department of Defense mandated the use of RFID tags for each item delivered by their suppliers.