It depends on the type of RFID technology involved. Passive systems typically cannot be extended. Near-field solutions rely on the creation of an electromagnetic field by the coils in the tag antenna and reader antenna. And passive far-field systems rely on the reader picking up faint signals from tags. I have never heard of anyone using repeaters to boost the signal—but even if you could do so, it is unlikely you could reach 1,000 meters.
Active systems do utilize repeaters. For example, Manor, Switzerland’s largest retail chain, is employing repeaters as part of an active ultrahigh-frequency (UHF) system built to track temperatures within its freezers and refrigerators (see At Manor, RFID Keeps Food From Spoiling). In addition, some companies that sell active RFID systems include repeaters as part of their offerings.
—Mark Roberti, Founder and Editor, RFID Journal
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