Introduction to RFID Technology
RFID (Radio Frequency Identification) is a technology that uses radio waves for non-contact data transmission, widely used in fields such as identity recognition, logistics tracking, and access control systems. The system is mainly composed of tags and readers, and the operating frequency band directly affects its performance and application scenarios. RFID tags can be divided into categories such as low frequency (LF), high frequency (HF), ultra-high frequency (UHF), etc. Among them, "IC" usually refers to integrated circuit cards (such as smart cards), and "ID" refers to identification cards, both of which are most common in the HF frequency band.
Frequency band classification and core characteristics
Low frequency (LF)
Operating frequency: 125kHz or 134.2kHz, with strong signal penetration and minimal interference to metals and water.
Features and Applications: Short reading distance (several centimeters to tens of centimeters), slow transmission speed, only able to read one label at a time; Commonly used in close proximity scenarios such as access cards, pet chips, and car anti-theft systems. For example, old-fashioned residential access cards are based on LF technology to achieve stable recognition.
High frequency (HF) and IC/ID cards
Working frequency: 13.56MHz, supports fast data transmission and multi tag recognition.
Features and applications: Reading distance of about 10 centimeters to 1 meter, moderate cost but susceptible to metal and liquid interference; IC cards (integrated circuit cards) and ID cards (identity recognition cards) mainly work in this frequency band and are suitable for scenarios such as bus card swiping, subway passage, library borrowing, and enterprise access control. For example, the daily "drip card" experience is mainly derived from HF RFID technology, which supports dynamic encryption and anti-counterfeiting for its security and maturity.
Ultra high frequency (UHF)
Operating frequency: 860-960MHz, supports long-distance recognition and high concurrency processing.
Features and Applications: The reading distance can reach several meters or more, the transmission speed is fast, and a large number of tags can be read simultaneously; Widely used in efficient scenarios such as warehousing and logistics, supply chain management, and retail inventory tracking. For example, in smart warehouses, the identification of entire pallets of goods can be completed within seconds through UHF systems, significantly improving efficiency. But it is sensitive to metals and liquids, and antenna design needs to be optimized to reduce interference.
Other frequency bands
Microwave frequency band: 2.45GHz or 5.8GHz, suitable for tracking high-speed moving objects (such as car ETC systems), with the advantages of long-distance and high-speed transmission, but at a higher cost.
Technological advantages and challenges
Dimension advantage challenge
Compatibility with multiple frequency bands covering different scenarios (such as LF for high interference environments) UHF frequency band is susceptible to metal/liquid interference
Efficiency UHF supports second level batch recognition, LF data transmission is slow, only supports single tag reading
Security: HF frequency band supports encrypted authentication (preventing IC/ID card duplication). HF recognition rate may decrease in complex environments
RFID technology is evolving towards miniaturization and intelligence, and the mature application of IC cards and ID cards in the HF frequency band has promoted the digitization of public services, while UHF plays a core role in industrial automation.
