As the title describes, this post is about RFID tag orientation. As trivial as it sounds for those who are RFID experts, this is the first lesson for all who freshly stumble onto this part of the wireless world. So before I continue, welcome! Now as far as the rule goes, just because the darn reader is not responding it does not mean the tag does not exist! Of course you know that, what am I thinking?!. Often the newbie struggles to explain the mystery of disappearing tags or so it seems. What I mean is, at most positions the RFID tag can be picked up by the reader fairly nicely. However when the tag is oriented a certain way (even just above the antenna), there is a dead silence from the reader. No, this is not a case of a The Twlight Zone.

EXPLAINATION : Tags receives power by magnetic coupling and receives maximum power at the best orientation. For maximum power induction, the magnetic field lines radiated by the reader antenna must be perpenticular to the RFID tag. In practise the tag can be rotated about 40 degrees either side of its optimal position and will still be read. However if the tag is placed parrallel to the magnetic lines, the waves are simply skimming on the surface of the tag and will not power it. In the video demonstration, it is using the Single Loop Single Panel configuration. There are several configurations such as Figure-8 Single Panel; as the name implies, the magetic waves flow in a Figure of 8 shape.

The diagram above illustrates the Single Loop Field Radiation pattern created from a single panel. The RFID tag is best positioned when

• RFID tag is closest to the radiating antenna, and
• RFID tag is interrogated right angle to the magentic lines passing through it

At the this optimal position, the RFID tag receives the maximum number of the magentic lines and receives maximum electrical induction. In the design of the RFID jewelry smart shelf for example, all possible orientations of the tag are considered during the design phase. For that we customize antennas for all shapes and sizes to effectively induce the RFID tags at varying orientations.

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I apologise for the poor video quality. It was done by one of the engineers…Give some time and we will redo this. This video basically shows a standard desktop antenna that reads about 20 jewellery items. With a specially made antenna, we could scan hundreds of jewelry items in the store all at the same time. Cool!

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John Shoemaker a noted RFID entrepreneur commented on the following about RFID customization solutions,

“This is not going to be an area where you just license some software — there has to be integration and collaboration”

“Vendors really are going to have look at requirements and structure software plans that address those requirements. It’s not a case for canned software,“.

For more, read the article The Failure of RFID.

I have been talking with our partners, and they all have this alikeness about RFID Solutions ~ “What are the standard RFID solutions packages to introduce to clients?”. Unfortunately RFID solutions rollouts take alot more than clicking the INSTALL button. Likely there will be existing software to talk to, defining data exchange protocols, cross platform integration issues, middleware issues etc.

In addition, the deployment environment may pose some challenges in a RFID rollout. If you forget everything else just remember what I am going to say now because it will save you from frustration while you are trying to figure “WHAT THE HELL WENT WRONG??”. Iron, steel and ALL ferrous metal attenuate RF fields. See below for 2 common stumbling blocks …

• On placing the antenna at a particular table, there are problems getting accurate readings. Why? TIP : Look under the table. If the table frame is made out of metal bar forming a closed loop, it is a deathstar to your setup. The close loop actually behaves like a bigger antenna that couple the RF signals.
• After connecting the antenna to the reader, and the reader to the computer via the serial where do you place the antenna? Usually… next the box itself while staring at the screen for some readings. What happens next is a total failure. What had happened? The JINX of RFID must surely be metal materials. In this case, the metal case had blocked out all the forward/return path of the flux lines resulting in total RFID reads failure.

There are probably a dozen other things on the subject of RFID rollouts. The point is, RFID solutions require more detailed design and planning to make the money worth.

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We have been talking to our customers as early as 2002 on implementing RFID based jewelry software management systems. We believe RFID can profoundly improve the efficiency of the jewelry business, that we have seen happen for some. The initial resistance to RFID adoption is not very different from what we hear now. Of course when they experienced 70% savings in costs relating to manpower costs, barriers to theft and other tangible benefits of having such a system, the stories changed inevitably.

I like to touch on one of the MAIN sound of resistance :

RFID is expensive, considering the equipment and tags investment. - TRUE? False.

1. In the case of Advago Jewellery, we partnered a software integrator sometime in 2003 to customize a RFID based solution. Previously Advago had employed more than 7 persons for inventory management, processing and handling transactions and among other manual tasks. Their operations personnel usually spent up to 2 to 3 days to account for all the inventory. When the RFID based solution was rolled out, the inventory process reduced for the company almost 70% of the time they would have taken before to complete the tasks.
2. Another key benefit : The RFID based solution opens up the entire supply chain for detailed scrutiny of which every jewelry item is tracked, yes even its location. At Advago, in one particular instance, loses arising from potential thefts were uncovered ahead of time by an automated detailed audit trail. Of course the management on discovering the loophole scrambled to put in extra checks.
3. Finally about the costs of the tags. Each tag costs about 1% and even less the retail value of each jewelry product in most cases. Amortize that tag cost over the many lifetimes of many jewelry pieces by tag reuse, you will see it further drives the overall costs lower. Compared to the capabilities that RFID enabled for a jewelry business, the costs-benefits are simply overweighing on benefits. In addition, we have observed the costs of RFID tags have steadily fall due largely to more efficient processes that manufacture them.

There are a few other common objections I hear, which I may cover in future posts. But I think I will stop here for now…

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