The Three-Sentence Summary
RFID (Radio Frequency Identification) uses radio waves to read data stored on a small chip without physical contact. A tag attached to an object stores an identifier; a reader broadcasts a radio signal, powers the tag (or reads it if it has its own battery), and captures the data. Unlike barcodes, RFID works through packaging, at distance, and on multiple items simultaneously.
Why Frequency Matters
Every RFID system operates on a specific frequency band. The band determines read range, data rate, and what materials the signal penetrates.
Low Frequency (LF) — 125 or 134.2 kHz
- Read range: 1–10 cm
- Penetrates water and animal tissue well
- Primary use: animal identification (ISO 11784/11785), access control, vehicle immobilisers
- Typical chips: EM4305, Hitag S, FDX-B
High Frequency (HF) — 13.56 MHz
- Read range: up to 1 m (typically 2–10 cm in practice)
- ISO 15693 standard covers industrial/logistics tags; ISO 14443A covers NFC and contactless payment
- Primary use: guard tour tags, library books, pharmaceutical track-and-trace, NFC
- Typical chips: ICODE SLI-X, ICODE SLIX2, NTAG213/215
Ultra-High Frequency (UHF) — 860–960 MHz
- Read range: 1–12 m with passive tags
- Fastest data rate; supports anti-collision for reading hundreds of tags per second
- Primary use: supply chain, retail inventory, animal ear tags, anti-metal tags, zip tie / seal tie tags
- Typical chips: Impinj Monza R6, NXP UCODE 8, Alien Higgs-3, NXP UCODE 9xm
Key Protocols You’ll Encounter
| Protocol | Frequency | Used For |
|---|---|---|
| ISO/IEC 18000-6C (EPC Gen2) | UHF | Supply chain, retail, logistics |
| ISO/IEC 15693 | HF | Industrial tags, guard tour |
| ISO/IEC 14443A | HF | NFC, contactless cards |
| ISO 11784/11785 | LF / UHF | Animal identification |
| ISO 18000-2 | LF | Access control, vehicle |
When you issue an RFQ, always specify the protocol — not just the frequency. A 13.56 MHz reader does not automatically read ISO 15693 and ISO 14443A tags interchangeably.
Passive vs Active vs Battery-Assisted
Passive tags have no battery. They harvest energy from the reader’s RF field. Lowest cost, indefinite lifespan, smallest form factor. Most industrial tags are passive.
Active tags contain a battery and broadcast continuously. They’re used for real-time location systems (RTLS) and long-range tracking (up to 100 m). Higher cost, battery replacement required.
Battery-Assisted Passive (BAP) tags use a small battery only to power the chip, not the transmitter. The reader still initiates communication. Better read range than fully passive, lower cost than active.
Choosing the Right Tag for Your Application
| Application | Recommended Type |
|---|---|
| Guard tour / security patrol | HF, ISO 15693, disc or button form factor |
| Livestock tracking | LF (implant) or UHF (ear tag) |
| Asset tracking on metal | UHF anti-metal (FR4 or ceramic substrate) |
| Laundry / textile tracking | HF ISO 15693, silicone or woven |
| Container / cargo sealing | UHF, seal tie format |
| Cable / utility pole tagging | UHF, zip tie format |
What to Ask a Tag Manufacturer
Before requesting samples, confirm:
- Protocol compatibility — does the tag match your reader’s air interface?
- Read range on your specific substrate — metal, liquid, and human tissue all reduce range
- Environmental rating — IP rating, operating temperature, UV resistance
- MOQ and lead time — most manufacturers require 500–1,000 pieces minimum
- Customisation — printing, encoding, and form-factor modifications available?
RFIDEcho provides free samples for qualified buyers. Contact our team to discuss your requirements.
