Can Tag Distance From a Reader Be Precisely Determined?

By RFID Journal

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Ask The ExpertsCan Tag Distance From a Reader Be Precisely Determined?
RFID Journal Staff asked 9 years ago

Is it possible to measure the distance of an RFID chip from a scanner, as long as it is within 1 meter of the scanning device? If so, would it require a bulky expensive scanner, or would something light suffice?

—Name withheld


Unfortunately, it would be very difficult to determine the distance between a tag and a reader with any precision. Many passive ultrahigh-frequency (UHF) readers, including handhelds, can measure the received signal strength (RSS) from a passive tag. However, RSS can be affected by waves bouncing off a floor or metal shelving, and it is difficult to translate RSS into a precise distance from a reader to a tag. I believe the level of precision required within 1 meter (3.3. feet) would be beyond what most interrogators currently available can provide. Perhaps some of our readers who design and build such devices might be able provide a more detailed answer by posting information below.

—Mark Roberti, Founder and Editor, RFID Journal

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