Understanding RFID Frequencies

Low Frequency (LF) (<135 KHz)

• Typically passive, read-only, or read-write transponders
• LF requires a longer, more expensive copper antenna
• Least susceptible to performance degradations from metals and liquid
• Shorter read ranges and typically larger transponder sizes

High Frequency (HF) (13.56 MHz)

• Typically passive, read-only, read-write, or WORM (write once, read many) transponders
• Less expensive than inductive LF transponders
• Relatively short read ranges and slower data rates when compared to higher frequencies
• Used with contactless smart cards
• Well suited for applications that do not require long reading range of multiple transponders; suitable for higher transponder-to-reader ratio applications
• Similar to LF transponders, good penetration through non-conductive materials and non-conductive liquids

Ultra-High Frequency (UHF) (868 MHz to 915 MHz)

• Active and passive, read-only, read-write, or WORM transponders
• Offers higher range capability, higher data transfer rates, and faster identification compared to lower frequencies
• In large volumes, UHF transponders have the potential for being less expensive than LF and HF transponders
• Good penetration through non-conductive materials and non-conductive liquids
• Provides a good balance between range and performance, especially for multiple transponder reading

Microwave (2.45 GHz, 5.8 GHz)

• Active and passive, read-only, read-write, or WORM transponders
• Similar characteristics to UHF transponders, but with faster read rates
• Cost is often twice as much or more than lower frequencies
• Good penetration through non-conductive materials but absorbed by water and water-based solutions
• Reflected by metals and other conductive surfaces offers the most directional signal.

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