I’m currently writing a scientific paper about the usage of RFID in smart factories, and I’ve got a question about active RFID tags. Is anyone using load modulation or backscattering, like passive tags do, or are they transmitting data the same way RFID readers do?
Active tags, by definition, have a power source and are able to broadcast a signal like a cell phone. They do not use load modulation or backscatter. In some cases, the active transponder might have a passive tag inside it to wake it up. This is common in toll-collection systems, which do not need to beacon all the time. So when a car approaches a toll booth, the passive reader sends a signal to the passive transponder, which wakes up the active tag and instructs it to start beaconing. Each proprietary active RFID system uses its own protocol to communicate with the readers.
—Mark Roberti, Founder and Editor, RFID Journal
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