What is the difference between low-, high-, and ultra-high frequencies?

Modified on Fri, 30 Aug at 2:57 PM

Behind the RFID acronym, there are different technologies. One way to differentiate these technologies is to look at the frequency at which the RFID system operates.

RFID systems throughout the world mainly operate in 3 different frequency bands: Low Frequency (LF), High Frequency (HF), and Ultra-High Frequency (UHF) bands. Radio waves behave differently at each of these frequencies and there are advantages and disadvantages associated with using each frequency band.

Low Frequency (LF) RFID

LF RFID systems operate at 125 kHz and 134 kHz. This frequency band provides a short read range of 10 to 50 cm, and has a slower read speed than the higher frequencies, but is not very sensitive to radio wave interference. These RFID systems are mainly used for animal identification and physical access control. The communication protocol is defined in ISO/IEC 18000-2. The LF spectrum is not considered a truly global application because of slight differences in frequency and power levels throughout the world.

High-Frequency (HF) RFID

Most HF RFID systems operate at 13.56 MHz with reading ranges between 10 cm and 1 m. HF systems experience moderate sensitivity to interference. HF RFID is commonly used for transport and event ticketing, payment, and data transfer applications. It is also used for secure documents like e-passports. There are several HF RFID standards in place, such as the ISO/IEC 15693 and ISO/IEC 18000-3 standards for item tracking. Near Field Communication (NFC) technology also operates at 13,56 MHz based on ECMA-340 and ISO/IEC 18092 standards. Other contactless smartcard applications (payment, ticketing, and access control) are based on ISO/IEC 14443 standards.

Ultra-High Frequency (UHF) RFID (aka RAIN RFID)

Passive UHF RFID systems comply with the GS1/EPC Gen2 and ISO/IEC 18000-63 standards and use the 860 to 930 MHz band. These RFID systems are also known as RAIN RFID. RAIN RFID is mainly used for fast asset identification, inventory, and tracking. Depending on the environment, read ranges are up to 10 m. This technology has also been designed for carrying GS1 keys (using the EPC format), identifiers, and Application Identifiers (AI) in order to simplify data exchange between different business stakeholders.