Would the presence of both ultrahigh-frequency and high-frequency tags in close proximity to one another affect the tags’ read accuracy?
It is certainly possible to use both passive UHF and HF transponders in a single ID card, as long as the antennas of the two transponders do not touch. The transponder antennas would be tuned to different frequencies and would not interfere with each other. If the antennas were to touch, however, then the metal of one antenna would detune the other and neither would work properly.
I hope this answers your question, and I look forward to seeing you at RFID Journal LIVE! in May.
—Mark Roberti, Founder and Editor, RFID Journal