Definition of RFID Tags
RFID tags are a type of tracking system that uses smart barcodes in order to identify items. RFID stands for radio frequency identification, and as such, RFID tags utilize radio frequency technology. These radio waves transmit data from the tag to a reader, which then transmits the information to an RFID computer program. RFID tags are frequently used for merchandise, but they can also be used to track vehicles, pets, and even patients with Alzheimer’s disease. An RFID tag may also be called an RFID chip.
How RFID Tags Work
An RFID tag works by transmitting and receiving information via an antenna and a microchip — also sometimes called an integrated circuit or IC. The microchip on an RFID reader is written with whatever information the user wants.
There are two main types of RFID tags: battery-operated and passive. As the name suggests, battery-operated RFID tags contain an onboard battery as a power supply, whereas a passive RFID tag does not, instead working by using electromagnetic energy transmitted from an RFID reader. Battery-operated RFID tags might also be called active RFID tags.
Passive RFID tags use three main frequencies to transmit information: 125 – 134 KHz, also known as Low Frequency (LF), 13.56 MHz, also known as High Frequency (HF) and Near-Field Communication (NFC), and 865 – 960 MHz, also known as Ultra High Frequency (UHF). The frequency used affects the tag’s range. When a passive RFID tag is scanned by a reader, the reader transmits energy to the tag which powers it enough for the chip and antenna to relay information back to the reader. The reader then transmits this information back to an RFID computer program for interpretation. There are two main types of passive RFID tags: inlays and hard tags. Inlays are typically quite thin and can be stuck on various materials, whereas hard tags are just as the name suggests, made of a hard, durable material such as plastic or metal.
Active RFID tags use one of two main frequencies — either 433 MHz or 915 MHz — to transmit information. They contain three main parts, including a tag, antenna, and interrogator. The battery in an active RFID tag should supply enough power to last for 3-5 years. When it dies, the unit will need replaced, as the batteries are not currently replaceable. There are two main kinds of active RFID tags: beacons and transponders. Beacons send out an information ping every few seconds, and their signal is readable from several hundreds of feet away. Because they are sending out data so frequently, their battery tends to deplete quicker. Like passive RFID tags, transponders require the use of a reader to transmit information. When within range of one another, a reader first sends out a signal to the transponder, which then pings back with the relevant information. Because they only activate when near a reader, transponders are much more battery-efficient than beacons.
Examples of RFID Tags
Since an active RFID is constantly sending out a signal, it makes an excellent choice for those looking for up-to-the-minute live tracking, such as in tolling and real-time vehicle tracking applications. They are an expensive product, but they do offer a long read range, which may be preferred depending on their application.
Passive RFID tags are a much more economical choice than active RFID tags, and cost around 20 cents each. This makes them a popular choice for supply chain management, race tracking, file management, and access control applications. While a passive RFID tag does not require a direct line of sight to the RFID reader, it has a much shorter read range than an active RFID tag. They are small in size, lightweight, and can potentially last a lifetime.
Since active RFID tags feature a larger, more rugged design than passive RFID tags, they are better suited for applications where durability is required. They are frequently used in toll payment transponder systems, cargo tracking applications, and even in devices used to track people.
Disadvantages of RFID Tags
RFID tags aren’t ideal compared to other tracking labels for a number of reasons. Some problems with RFID include different security and technological issues.
Because an RFID tag cannot distinguish between readers, the information can be read by almost anyone once it has left the original supply chain. Because RFID readers are so portable, and the range of some tags so great, scammers can gather information they would otherwise not have access to. This means that anyone can collect potentially sensitive information without a person’s knowledge.
Another security concern for consumers is that RFID tags can be linked to individual credit cards, creating the potential for financial theft and fraud.
Technology-wise, RFID tags are problematic largely because there are no real global or industry standards. Since they operate on radio frequency, RFID tags and their systems can also easily become jammed or disrupted, reducing their usability. This results in longer wait times and decreased productivity in both retail and warehouse settings.
There are also signal issues that can occur with RFID systems, including collision — when signals from two or more readers overlap, and interference caused by metal, water, or other magnetic fields in the surrounding area.
An RFID system is also time-consuming and labor-intensive to set up. Companies need to test various hardware and tag systems to determine the best fit, which can take months to arrange. In addition to the cost of the RFID system itself, such as RFID tags and scanners, an increase in time and labor also means an increase in cost.
These types of disadvantages are often avoided with the use of barcodes, which is why they are still a popular data collection and inventory control choice for many businesses.