From What Range Can RFID Tags Be Interrogated?

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Ask The ExpertsFrom What Range Can RFID Tags Be Interrogated?
RFID Journal Staff asked 7 years ago

What is the maximum read range of the tags and readers available to date?

—Name withheld


We are asked this question often, but the answer is complicated. Active tags typically have a read range of up to 1,000 meters (3,281 feet). Last year, we wrote about a California RFID technology startup called Iotera that was launching a new active radio frequency identification tag that could transmit location- and sensor-based data at a distance of up to four miles. The tag—part of Iotera’s Wireless Sensing and Tracking Platform—includes a GPS unit, a temperature sensor and an accelerometer so that it can transmit its longitude and latitude to a reader, along with its temperature or movement status (see
Iotera Develops Active RFID Tag With 4-Mile Read Range).

The read range of passive ultrahigh-frequency (UHF) tags depends on the tag antenna’s size and the type of reader antenna being used. I have seen an ordinary reader interrogate Omni-ID‘s Ultra tag from 100 feet away. I have seen a beam-steerable phased-array antenna read an ordinary passive UHF tag, such as Alien Technology‘s Squiggle tag, at a distance of 60 feet. And I have seen a beam-steerable phased-array antenna read an ordinary tag from 600 feet away when the tag is powered by an exciter located within 20 feet. In other words, the send and receive function are separated and the antenna sending energy to the tag is close to the tag, while the antenna reading the tag is far away.

I hope that answers your question.

—Mark Roberti, Founder and Editor, RFID Journal

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