Contrary to Tina Turner, frequency like love has everything to do with it.  RFID technologies operate at many frequencies, but I will only cover the most common passive ones here:  low-frequency (125 MHz), high-frequency (13.56 MHz) and ultra high-frequency (860-960 MHz).

Low-frequency (LF) passive solutions operate around 125 MHz, use less power and are less susceptible to liquids.  Read ranges are in inches.

High-frequency (HF) passive RFID solutions operate around 13.56 MHz, use more power and are less susceptible to metals.  Read ranges are at most a few feet.

Ultra-high-frequency (UHF) passive RFID solutions operate between 860-960 MHz (depending on the country), uses the most power of the three and are less likely to pass through materials.  The data transfer rate is faster than LF and HF and the read ranges can be as high as 30 feet or more.

As you can see, frequency plays a role in determining the read range of a solution.  Next time I will continue with the role the reader and antennas play.

Passive UHF RFID readers can affect the read range depending on the manufacturer and the power level.  In the US, FCC regulations cap the output power at 4 watts, whereas in Europe it is only 1 watt.  There are studies available for purchase that detail the testing results of readers and antennas in a controlled, RF-friendly environment.  These are appropriate for general guidelines, but each environment is different and a reader that did not test at #1 in the study may be the better one in your environment.

Passive UHF RFID antennas can also affect the read range depending on the manufacturer, the type of polarization and the gain.  Antennas can be either linearly polarized or circularly polarized.  When the direction of the electric field is in one plane, it is called “linear polarization”.  When the direction of the electric field is rotated around the axis of propagation, it is called “circular polarization”.  Linear polarized antennas will provide a longer read range as compared to circular.  Also, an improvement in antenna gain is achieved by focusing the radiated RF into narrower patterns for the purpose of increasing the power in a specific direction.  In general, the higher the gain the longer the read range.

My next post will cover how RFID tags affect the read range.

According to RFIDUpdate, The newest mobile RFID reader is more than six feet wide, 17 feet long, weighs a few thousand pounds, and is known more for its horsepower than its MHz. Ford’s popular F-150 pickup trucks are now available with an RFID reader integrated in the bed to monitor cargo. …Ford Work Solutions is a series of software and services for vehicle, worker, and asset management. It is targeted to contractors and other customers who use their vehicles for work. The applications rely on an in-dash computer now offered as an option for 2009 model year F-150 and F-Series Super Duty pickups and E-Series vans….Customers receive a supply of specially designed Gen2 RFID tags to apply to the tools, toolboxes, containers, or other items they want to track.

So, how cool is that?  Your truck can actually track your assets for you and before you leave a site you can check to make sure you have everything you came with!

If this is a little out of your price range, remember that flowers, cards and chocolate work well too!  Happy Valentine’s Day.