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Wednesday, December 8, 2010

RFID Technology: Spectrum used for RFID…Sequel III

Last week, I touched on different bands of frequencies such as Low frequency, High Frequecy and Ultra high frequency. There is one question will be coming to your mind about the advantages and disadvantages of these frequencies and their usage.

Today, I will give brief about these bands of frequencies. This will complete the high level understanding of RFID technology and their usage. J

1- Low RFID frequencies (125 KHz):
In general their advantages are:
  • Least affected by their surroundings
  • Least affected by the presence of water
Their disadvantages are:
  • Can’t read tags over distances of more than about half a meter.
  • Can’t read lots of tags at the same time (lower read speeds)
  • Larger tags (may not fit on small objects)
Typical applications/usage:
  • rfid access control systems
  • point-of-sale checkouts
  • identifying animals
  • monitoring manufacturing processes, especially wet ones
2- High RFID frequencies (13.56 MHz):
In general their advantages are:
  • Cost less than most LF
  • Can read tags over a larger distance than LF
Their disadvantages are:
  • Shorter tag read range (up to 2m) than UHF
  • Not best for reading many tags at the same time, but better than LF
Typical applications/usage:
  • rfid library system
  • identification of bags at transport gateways
  • smart cards
 3- Ultra high RFID frequencies (868 -870 MHz (Europe) and 902 -928 MHz (USA)):

In general their advantages are:
  • Generally cost less than LF or HF
  • Identify objects fast because of fast read speed
  • Good range (maybe up to ten metres in the 860 to 956 MHz band, and tens of metres at 433 MHz)
 Their disadvantages are:
  • There can be more RF transmission complications
Typical applications:
  • Logistics - big operators such as Walmart
  • Making toll payments without stopping
  • Accessing car parks
 Next week I will touch base on some Myth on RFID….


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