Ultra High Frequency (UHF) RFID Tags & Systems

What are UHF RFID Tags and Systems? What are their applications and advantages over LF and HF RFID systems? What frequencies do UHF tags operate at?
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- everything RF

May 2, 2018

The Ultra High Frequency (UHF) band is the frequency range from 300 MHz to 1 GHz. RFID systems that operate in this frequency band are called Ultra High Frequency (UHF) RFID Systems. UHF RFID tags/readers usually operate at 433 MHz and from 860 to 960 MHz. UHF RFID tags operate using the far-field radiative coupling principle or backscatter coupling principle.

UHF RFID tags have a much higher read range when compared to LF and HF tags. The high data transfer rate makes UHF RFID tags ideal for applications that need to read multiple items at once, such as boxes of goods as they pass through a door into a warehouse or racers as they cross a finish line.

The read range of UHF RFID tags can be as high as 50 feet which is much higher than that of LF and HF tags. The longer read range opens up a set of new applications for RFID such as electronic toll collection and parking access control.

UHF tags do have some downsides, one being that they operate at a higher frequency and thus have shorter wavelengths which attenuate fairly quickly and are also very sensitive to interference. These tags cannot easily be read while attached to objects containing water and animal tissues because water absorbs UHF waves. The UHF tags also do not work well with metals, as they get detuned when they are attached to metal objects.

UHF RFID Tag Properties

Tag TypePassive / Battery Assisted / Active
Frequency433 MHz and 860 to 960 MHz
Read RangeUp to 50 feet
Read SpeedVery Fast
Read Multiple Tags SimultaneouslyYes
Works with MetalNo
Works with WaterNo
CostVery Low