I have an RF tag that operates at 868.5 MHz. Can it be read by any RFID reader of nearby frequencies, or only by one designed to operate at 868.5 MHz?
—Shanish P.
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It sounds like your tag is a passive ultrahigh-frequency (UHF) tag, most likely based on the ISO 18000-6C standard. It was likely designed to be used in Europe, where that portion of the spectrum is allocated for RFID systems. Thus, you would achieve the best performance from that tag if you used a passive UHF reader designed to work in Europe at that particular frequency. But any passive UHF reader that employs the same standard can read the tag.
UHF readers can usually be configured to operate between 850 MHz and 960 MHz. If such an interrogator designed to work at 915 MHz encounters a tag at 868.5 MHz, the read range will be less than with a tag tuned to 915 MHz.
—Mark Roberti, Editor, RFID Journal