How are the devices affected by EM energy?
It depends. If you were using a passive high-frequency (HF) system and if there was electromagnetic interference (EMI) from 2.45 GHz devices, it would unlikely have much impact at all. However, if you were using a passive ultrahigh-frequency (UHF) system and another device was operating at 915 MHz, it would likely interfere with the RFID system, and vice versa. This would make it difficult to read tags consistently. The solution would be to shield the tag and reader from the EMI. This could be accomplished using sheets of Mylar or aluminum, or some kind of metal mesh, with which you could create a Faraday cage.
—Mark Roberti, Founder and Editor, RFID Journal
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