RFID Soup

Tag

Page history last edited by Bill Wilkinson 2 yrs ago

Tag

HF RFID Tag Inlay

A tag is the transceiver attached to physical items in an RFID system. The tag consists of a microchip attached to an antenna, and can be manufactured in various form factors such as a printable label or plastic encapsulation. Each microchip may be factory programmed with a unique Tag ID (TID). The tag may also include additional components such as a battery or sensor. Passive tags are powered by the interrogator, while semi-passive (battery assisted passive (BAP)) and active tags contain a battery. The data carried on a tag may be limited to a unique identifier, or include additional information.

Finished Form Factors

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Image credit: High Tech Aid

Tag Type Comparison

The table below is a generalization of the differences between tag types. As with any generalization, exceptions can be found. For example, there are passive tags with large memories, and Real Time Location Systems based on passive tags.

**General Differences Between Tag Types**
Category	Battery	Sensor Capable	Memory Capacity	Processing Capability	Typical Communication	Typical Applications
Active	Yes	Yes	Larger	Yes	Transmitter	High Item Value Long Read Range Real Time Location Systems
Semi-Passive (Battery Assisted Passive)	Yes	Yes	Larger	Yes	Passive Backscatter (μWave, UHF) Inductive Coupling (HF, LF)	High Item Value Short Dwell Time Short Read Range
Passive	No	Yes but Uncommon	Smaller	No	Passive Backscatter (μWave, UHF) Inductive Coupling (HF, LF)	Low Item Value Short Read Range