Low Frequency (LF) RFID Tags & Systems

What are LF RFID Tags and Systems? What are their applications and advantages over HF and UHF RFID systems?
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May 2, 2018

The Low Frequency (LF) band is the frequency range from 30 KHz to 300 KHz. RFID systems that operate in this frequency band are called Low Frequency (LF) RFID Systems. LF RFID systems operate at 125 KHz and at 134 KHz (depending on the application and on the country where it is being used). The LF tags are based on inductive coupling technology which means that the RFID reader induces a current in the RFID tag which then powers the RFID tag and sends out some basic identification information to the RFID reader. LF tags are usually passive and do not require a power source or battery.

Low Frequency RFID tags have a long wavelength and can penetrate thin metal surfaces (HF and UHF tags can usually not be used with metallic substances). They can also operate in environments with high water content - so fruits, liquids and even animal tagging.

Since LF RFID tags are based on inductive coupling technology their read range is limited to a few centimeters or inches. This limited range can be used in a number of applications to provide an increased level of security i.e the RFID system will only work when the tag is close to the reader. This can be used when wanting to exchange sensitive information or for car ignition, where the RFID tag can be embedded in the key and read by a reader that is in the car. The system will only work when you are close to the car.

LF RFID systems are ideal for access control, asset tracking, laundry, animal identification, automotive control, as vehicle immobilizers, healthcare, and various point-of-sale applications (such as Mobil/Exxon SpeedPass).

LF RFID Tag Properties

Tag TypePassive
TechnologyInductive Coupling
Frequency125 KHz / 134 KHz
Read RageShort (few cm to Inches)
Read SpeedSlow
Works with MetalYes
Works with LiquidsYes