Classification of RFID

RFID, or Radio Frequency Identification technology, is an automatic identification technology that uses radio signals to identify specific objects, people, or animals. RFID technology can be classified into different types based on different classification criteria.

The following are the RFID classifications based on different criteria:

Operating Frequency

• Low Frequency (LF): 125 kHz to 134.2 kHz, suitable for close-range reading, such as animal identification and access control. See common LF Chips.
• High Frequency (HF): 13.56 MHz, suitable for general RFID applications such as libraries, supermarkets, and public transportation. See common HF Chips.
• Ultra High Frequency (UHF): 860 MHz to 960 MHz, suitable for large-scale reading, such as logistics and warehousing. See common UHF Chips.
• Extremely High Frequency (EHF): 30 GHz to 300 GHz, suitable for short-distance high-speed data transmission, such as smart homes and car networking.

Tag Storage Medium

• Passive: No built-in battery, requires an external RFID reader to provide power to activate the tag and perform data exchange.
• Semi-passive: The tag has a built-in battery for power supply, but only works when activated by the reader, and remains in sleep mode at other times.
• Active: The tag has a built-in battery for power supply and actively sends signals for data exchange.

Communication Mode between Tags and Readers

• One-Way Communication (Uni-Directional): The tag can only be read by the reader to obtain stored information, and cannot transmit data back to the reader.
• Two-Way Communication (Bi-Directional): The tag can communicate with the reader in both directions.

Implementation Method

• Active: Uses radio waves to activate the tagged object, which then returns information to the reader. These tags have their own power source.
• Semi-Passive: Similarly uses radio waves to activate the tag, but these tags do not require batteries; they obtain the required power from the input radio field.
• Passive: Also uses radio waves to activate the tag, but these tags have no power source or battery and must obtain the necessary energy from the radio field sent by the reader.