Where Can I Find RFID Readers Able to Scan an Entire Room for Tags?

By RFID Journal

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Ask The ExpertsWhere Can I Find RFID Readers Able to Scan an Entire Room for Tags?
RFID Journal Staff asked 12 years ago

I'm interested in purchasing tags and interrogators, and would like to have approximately 20 to 30 people within a room, each with a passive tag. The room would be about 30 feet in length, 9 feet in width and 8 feet in height, and the tags would be located within a person's bag or pocket. I would like the readers positioned around the room, each separately polling a specified area for tags. After a few seconds, I would like the polling to stop. Can you provide any suggestions as to which readers and tags would be appropriate for such a task? And would the power emitted by the devices pose any risk to human health?

—Name withheld


Just about any ultrahigh-frequency (UHF) system could be set up to cover a room. Passive UHF readers could be set up around the room, and could start and stop reading as directed. However, there would be no way, using a conventional UHF system, to determine precisely where someone was located within a room. You could not, for instance, divide the room into four quadrants and know for certain that a person was in one quadrant and not another, if people were standing near the border of two quadrants.

Mojix offers a phased-array antenna that allows a user to more precisely locate tags within three dimensions (see Mojix Takes Passive UHF RFID to a New Level). The system is accurate to within 3 feet, so if you needed to precisely know that a person was on one side of a line or another, that would not work. If you were willing to utilize an active system, you could try ultra-wideband (UWB) technology, which can locate tags to within a few centimeters.

—Mark Roberti, Founder and Editor, RFID Journal

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