RFID Thoughts

Several years ago I attended an RFID conference in Las Vegas. It was the first time that I had been to one and was very excited to see how RFID was being deployed and how Walmart’s push for RFID several years earlier had impacted the implementation of this technology. During this two day conference several early adopters presented and explained how challenging a simple technology can be to implement. It was well understood by the early adopters that this was a growing technology and the challenges they faced today would soon be overcome. The 90% read rate of the tags as one presenter stated was due to quality control of the tags and some times it was a result of antenna placement. Even with all the challenges and incorrect cost estimates the benefits were obvious. They felt confident that the tags quality would increase and that with education the antenna placement problem could easily be overcome. Other problems such as the environmental impacts on RFID where the basic physics of how radio frequencies are retrieved from a tag would be a greater problem and much more skepticism was around that it was a solvable problem.

This past April I had the opportunity to attend the RFID Journal Live ’11 in Orlando, FL. It has been over 2 years since I last attended an RFID conference and I was interested in how far we have moved forward over coming these challenges and what new challenges have arisen. It was amazing to see just how far we have come in the last two years with this technology and how many vendors are involved with this area. From my observation the read rate challenges have been reduced down to less than 2% with a two pronged approach. First, the quality of the tags is much greater today before they leave the factory. The factories are selling more tags and have more capital to invest in quality control practices and as a result have increased the value of their product and at the same time reducing the cost to the customer. This was a win win situation and will help move this industry to a much better place. Second, several vendors were selling a combination printer/RFID reader writer. The user would purchase a roll of RFID tags made for this custom printer. As the tag was pulled through the printer it would first have the information written to the tag then move on to a reader. The reader would validate the information written to the tag and prints an X on the tag if it failed the test. If the tag worked correctly it would print the customers image on the label. This two pronged approach to read/write validation has reduced the failure rate to almost be non-existent.

Another problem the industry has overcome with a somewhat simple solution is the physical inability to power an RFID antenna while it is attached to a metal surface, such as a car body or tools. This problem exists because the antenna on the tag serves two purposes on Passive RFID (pRFID) tags. The antenna provides the microchip power through a magnetic field supplied by the radio waves and at the same time provides the data transmission over these same radio waves. When the tag is attached to a metal surface or any other surface that could impact the radio waves then the signal strength is too weak to power the chip. The simple solution put in place is encase the tags antenna with a compound that does not interfere with the radio waves and provides a knockoff distance between the surface it is attached to and the antenna. Simple yet effective.



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