Installation guide

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Wi-Fi Location-Based Services—Design and Deployment Considerations
OL-11612-01
RFID Tag Considerations
Figure 55 Active and Passive RFID Comparison
Within these basic categories of RFID tags can be found subcategories such as semi-passive, transponder
active, and beaconing active RFID tags.
Passive RFID Tags
Passive RFID tags typically do not possess an onboard source of power. Instead, the passive RFID tag
gets all its power from an energizing field that emanates from an RFID reader or interrogator. In the
typical passive RFID tag design, the tag has no source of power and cannot communicate with host
applications unless it is within an acceptable range of an RFID reader.
Interrogators come in many forms, with two common examples being handheld devices (shown on the
left in Figure 56) and others being large stationary models capable of reading many tags simultaneously
as they pass through a choke point (shown in the center of Figure 56). Embedded sub-miniature passive
RFID readers and tags (shown on the right in Figure 56) can be used in applications such as immediate
verification of proper liquid and gas supply hoses or electrical connections.