RFID

RFID

Radio-Frequency Identification (RFID) is a wireless technology that uses electromagnetic fields to automatically identify and track tags attached to objects. Unlike optical systems such as barcodes, RFID does not require line-of-sight alignment between the reader and the tag, enabling hands-free bulk reading of hundreds of items per second.

How RFID Works

An RFID system has two core components: an interrogator (reader) and one or more transponders (tags). The reader emits a radio-frequency carrier wave. When a tag enters the field, it harvests energy from the wave (for passive tags) or uses its own battery (for active tags) and modulates the signal to send stored data back via backscatter or load modulation.

The data carried on a tag is typically an EPC (Electronic Product Code) -- a globally unique identifier that links the physical object to digital records in enterprise systems. Readers decode incoming signals, filter duplicates, and pass structured events upstream through middleware to warehouse management systems, ERP platforms, or cloud analytics.

Frequency Bands and Standards

RFID spans multiple frequency bands, each with different physics and trade-offs:

UHF RFID dominates supply chain and retail because of its long read range, low per-tag cost (under $0.10 at volume), and the mature EPC Gen2 standard that ensures multi-vendor interoperability.

Industry Impact

Retailers deploying item-level tagging typically see inventory accuracy rise from 65-75% to over 98%. In logistics, RFID-equipped dock doors (portal readers) verify entire pallet contents in seconds. The technology is also central to pharmaceutical serialisation under FDA DSCSA and the upcoming EU Digital Product Passport.

See also: RFID Tag Selector | Frequency Bands Guide | Tags