High Frequency (HF) RFID
13.56 MHz
What is HF RFID?
High Frequency (HF) RFID operates at 13.56 MHz, a globally allocated ISM (Industrial, Scientific, and Medical) frequency. It is the most widely deployed RFID frequency in the world by installed base – every contactless bank card, transit card, e-passport, and NFC smartphone interaction uses 13.56 MHz.
HF sits between LF and UHF in both frequency and capability. It offers faster data rates and longer range than LF, while being more tolerant of metal and liquid than UHF. The 13.56 MHz band supports a rich ecosystem of standards, chip families, and applications – from basic library book tags to cryptographically secure payment credentials.
How it works
Like LF, HF RFID uses near-field inductive coupling. The reader generates an alternating magnetic field at 13.56 MHz through a coil antenna. A tag within range couples inductively with this field, harvesting energy to power its chip. The tag communicates by load modulation – it varies the electrical load on its antenna, which the reader detects as tiny changes in the reader's own antenna impedance.
At 13.56 MHz the wavelength is approximately 22 metres, so at typical read distances (under 1 m) communication is entirely in the near field. The higher frequency compared to LF allows for significantly faster data transfer – up to 424 kbps (NFC) or 848 kbps (ISO 14443) – and supports robust anti-collision protocols for reading multiple tags.
Key standards and protocols
| Standard | Range | Speed | Use |
|---|---|---|---|
| ISO 14443 (Type A/B) | Up to 10 cm | Up to 848 kbps | Contactless payment (Visa, Mastercard), e-passports (ICAO 9303), access control (MIFARE, DESFire). The most widely deployed HF standard. |
| ISO 15693 | Up to 1 m | 26 kbps | Library systems, industrial asset tracking, laundry tags. Trades speed for longer range. NXP ICODE SLIX is the dominant chip family. |
| NFC Forum (NDEF) | Up to 5 cm | Up to 424 kbps | Smartphone NFC interactions, smart posters, product authentication. Built on ISO 14443. See NFC . |
| ISO 18000-3 | Up to 1 m | Varies | The RFID-specific air interface standard for 13.56 MHz. Encompasses multiple modes including ISO 14443 and ISO 15693. |
Major chip families
| Chip family | Manufacturer | Standard | Security | Typical use |
|---|---|---|---|---|
| MIFARE Classic | NXP | ISO 14443A | Proprietary Crypto-1 (broken) | Legacy transit and access cards. Being replaced due to known cryptographic weaknesses. |
| MIFARE DESFire EV3 | NXP | ISO 14443A | AES-128, 3DES | Modern transit, access control, micro-payment. Common Criteria EAL5+ certified. |
| NTAG 213/215/216 | NXP | NFC Forum Type 2 | Password (32-bit) | NFC tags, smart posters, Nintendo Amiibo (NTAG215), product interaction. |
| NTAG 424 DNA | NXP | NFC Forum Type 4 | AES-128, SUN authentication | Product authentication, anti-counterfeiting. Generates unique cryptographic URL on every tap. |
| ICODE SLIX2 | NXP | ISO 15693 | Password | Library systems, industrial tracking, laundry. |
| ST25T series | STMicroelectronics | ISO 14443/15693 | Various | NFC tags, dual-interface cards, IoT. |
Read range
HF read range depends heavily on the standard and antenna design:
- ISO 14443 (proximity): up to 10 cm. Deliberately short for security-sensitive applications like payment.
- ISO 15693 (vicinity): up to 1 metre with large reader antennas. Used where longer range is needed (library gates, inventory).
- NFC: up to 5 cm in practice, limited by smartphone antenna power. See NFC .
Advantages
- Global frequency: 13.56 MHz is available worldwide with no regional variations, unlike UHF which differs by country.
- Rich security: HF chips support AES-128 encryption, mutual authentication, and secure messaging – essential for payment and identity.
- Fast data transfer: Up to 848 kbps allows reading/writing larger data payloads including biometric data in passports.
- Anti-collision: ISO 14443 and ISO 15693 both support multi-tag reading, though not as fast as UHF.
- Smartphone compatible: Every modern smartphone has an NFC reader at 13.56 MHz, enabling consumer-facing applications.
- Mature ecosystem: Billions of HF cards and tags deployed, extensive tooling, wide chip selection.
Limitations
- Shorter range than UHF: Maximum 1 m (ISO 15693) vs up to 12 m for UHF. Not suitable for warehouse-scale inventory.
- One-at-a-time in practice: While anti-collision exists, bulk reading speed is much slower than UHF (which can read hundreds of tags per second).
- Cost: HF smart cards with encryption (DESFire) are significantly more expensive than UHF inlays.
- Metal sensitivity: Better than UHF but worse than LF. Metal surfaces near the tag antenna can detune it.
Common applications
- Contactless payment: Visa payWave, Mastercard PayPass, Apple Pay, Google Pay all use ISO 14443 at 13.56 MHz. The card or phone communicates with the terminal in milliseconds.
- Public transit: Oyster (London), Suica (Tokyo), Opal (Sydney), and hundreds of other transit systems use HF smart cards for fare collection.
- Access control: Modern systems use MIFARE DESFire or iCLASS SE for building and campus access, replacing legacy LF systems.
- E-passports: ICAO 9303 specifies ISO 14443 for the contactless chip in electronic passports, storing biometric data.
- Libraries: ISO 15693 tags in books enable self-checkout, automated returns, and inventory with walk-through detection gates.
- Product authentication: Tamper-evident NFC tags verify authenticity of wines, spirits, pharmaceuticals, and luxury goods.