RFID Tags: Active, Semi-passive, and Passive

rfid tagThere are three basic types of RFID tags; active, semi-passive, and passive. Active and semi-passive tags use internal batteries in order to power their internal circuits. Active tags also use their battery to send radio waves to a RFID reader, whereas semi-passive tags rely on the reader to supply power for its broadcasting. Both active and semi-passive tags are most commonly used for large-scale applications that need to be read over greater distances. Because of this, they typically broadcast high frequencies from 850 to 950 MHz and can be read from over 100 feet away.

In contrast, passive RFID tags rely solely on the reader to supply power. The tags can be read from 20 feet away, and are often used for more small-scale applications. In addition, passive RFID tags are made to be disposable for easy replacement and use on consumer goods. Since they are disposable and used in such large quantities, passive RFID tags typically only cost between 7 and 20 cents each.

Within the realm of active, semi-passive, and passive RFID tags, there’s also an option as to how much data storage is allotted—read-write, read-only, and WORM, which stands for “write once, read many.” As the names suggest, a read-write tag’s data can be added to or overwritten, where a read-only tag cannot be overwritten. WORM tags can also have additional data added, but can not be overwritten. Typically, passive tags are read-only and active tags are read-writable.

With advancements in passive RFID technology over the past few years, RFID technology has spread a considerable amount, but still has a lot of room for expansion. If manufacturers can drive the cost per tag to under 5 cents each, I predict that more companies will start using passive RFID tags for their consumer-based goods.

If you’re interested in learning how RFID can be a valuable solution for your company, you can learn more here.