I would like to be able to avoid reading any tags that are beyond a 3-meter range. Is this feasible?
Passive UHF RFID readers almost always have software that allows you to reduce or increase the amount of power output to antennas. Reducing power output would decrease read range. A good tool for measuring the amount of energy reaching a particular area is the Power Mapper 5, made by ePix Ltd. (see The New Power Mapper 5).
The only other way to reduce reads that I know of would be to use shielding, such as a sheet of Mylar. The energy would bounce off the shielding, which would prevent tags behind the shield from being interrogated. However, this is not always feasible in an operational environment.
—Mark Roberti, Founder and Editor, RFID Journal
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