Wondering about how similar—or how different—active and passive RFID are? Here’s a quick rundown on the two radio frequency technologies:
As you can tell, active vs. passive RFID serve very different use cases—and in fact, there are very few times when you would have to choose between the two for your tracking system. To make the differences even more clear, we’ve broken out the important characteristics of each and compared them below.
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Use Case & Range |
Is your goal to keep track of inventory located in a specific room? If so, passive RFID is probably ideal for you. But if you need to actually monitor the physical location of a tagged object throughout your entire building, active RFID will be your best bet. It comes down to scalability and functionality. Passive readers can only read tags roughly one to five meters away—so scaling a system that would work for actually tracking the location of an item would require a large number of readers. Active RFID systems, on the other hand, scale easily because a reader can detect a tag farther than 100 feet away. This means you could, in some instances, cover 10,000 square feet with only one reader and a few reference points. AirFinder active RFID tags, for example, calculate their location relative to reference points and send this data to nearby readers. The readers then send the location data to the gateway, which is then sent to the AirFinder web application. The application takes the data and provides the user with an estimated location of each tagged asset. |
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Tag Cost |
If the cost of the tag is the main driver in your decision, passive RFID will win every time. Passive tags are typically between 10 and 50 cents each, whereas active tags range between $5 and $15 each. |
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Battery Life |
Passive RFID tags are simple and battery-free—meaning they’ll last virtually forever, which is a big part of their appeal. Active RFID tags, on the other hand, typically last between three to five years, with some lasting up to 10. While passive is the clear winner when it comes to tag longevity, it’s worth noting that active RFID tags are known to have a much better battery life than some other RTLS technologies (like ultra wide-band and WiFi). |
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Environmental Constraints |
Passive tags are easier to completely seal, which makes them more suitable for for more ruggedized environments. Since active tags require batteries, it’s more difficult to ruggedize them. Keep in mind that active tags also cannot always withstand the autoclaving process—so if sterilization is required for your tracking use case, you’ll want to consider all your options. |
Yes! In fact, that’s something AirFinder is examining for the future. We’re currently looking into adding passive functionality into our active tags, for two reasons. First, it can provide time-sensitive chokepoint functionality, so we’ll be able to tell more accurately if a tagged item leaves a particular area. Second, it gives those who require active RFID scalability but could use passive RFID functionality a better option in the market. Stay tuned for updates!
