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May 17, 2022

The “Secret” to Ensuring Accuracy and Repeatability in RFID Testing – Properties of an RFID Test Chamber

When our customers think of where measurement accuracy and repeatability in a tag testing setup originate from, they usually mention things like output power resolution, power setting accuracy, measurement distance measured down to a millimeter, angular alignment, and high quality matched antennas, test grade RF cables, etc…  My claim is, and it’s not even a bold claim, but more like a friendly reminder, that the most significant factor in achieving result repeatability and comparability is actually the environment.

So, what is the best route to a great environment? Well, clearly, the best solution is to use a closed and controlled environment like an anechoic cabinet specifically designed for RFID measurements. At Voyantic, the most iterated and refined cabinet is the C50. It is also the smallest of the offered cabinets, supporting the TIPP/ARC compatible four antenna measurement layout.

  

ARC / TIPP antenna arrangement and the C50 cabinet

Test Distance

The C50 name comes from the 50cm nominal measurement distance and the circular arrangement of the antennas. The choice of the distance is a sweet spot to be as close as possible for best accuracy and dynamic range, but far enough to be in an accurate enough representation of a  far-field for most average-sized tags, tagged items, and item stacks. Any further attempt to still reduce the distance rapidly ends up in the antennas not physically fitting anymore or just coupling into each other as they would sit in each other’s reactive near field.

The Cabinet Size

When you add on top the 50cm test distance the size reserved for the test object, clearance for the Fresnel zone, the volume required by the UHF range pyramid absorbers optimized for each wall, and the outer shielding, you still actually end up with a reasonably sized package. The C50 chamber totals to dimensions of 1,55m x 1,50m x 1,05m. This typically doesn’t sound important in any way, until one is planning the location for the cabinet and the transport route up to the very spot. These dimensions have not evolved by accident but rather designed from experience so that the cabinet would fit through as many door openings, narrow corridors, and elevators as possible. Also, the total weight remains in the 200kg range, making it movable by a few sturdy RFID test engineers without renting any additional equipment.  

A Sturdy RFID Engineer

Low Reflections

One of the hardest parameters to get right is the level of unechoicity. It wouldn’t be too hard in a totally empty space, but as the item under test requires a computer-controlled rotatable platform withstanding over 10kg of weight and still being totally stealthy, things get a lot trickier. The rotation mechanism and the support platform should not provide alternative radio paths from the antenna to the tag which could create a multipath situation and decrease the accuracy.

Turntable Design

To achieve the required stealth properties, anything bulky, parallel, and flat should be avoided. Also, electrically conductive materials must be avoided at all costs, except for the shortest of screws.  This means that conventional mechanical design is thrown right out of the window and other approaches are needed. Our chambers have fully ceramic bearing structures, Kevlar belts, fiberglass axles, Nylon bolts, and numerous foam structures. Most other structural parts are carefully designed from polyamide with most of the material hollowed out and any parallel and straight lines broken to reduce the RF footprint as much as possible.

Components in the chamber are designed to minimize any RF reflections.

To see the full range of available Voyantic anechoic chambers, download our R&D Solutions Catalogue ›

Download R&D Solutions Catalogue

Learn more about the Voyantic Tagformance® Pro system, accessories, and test chambers!

By combining RAIN RFID and NFC testing into one compact test device, our all-new Tagformance Pro is a true all-in-one tool for anyone either developing or using RFID technology.

Aug 06, 2020

RAIN RFID in Tool Management

中文版 Chinese version

Recent developments in RAIN RFID technology, markets, and global regulations have made the RAIN RFID an even more interesting technology. I believe that with the RAIN RFID a traditional industry such as tool manufacturing can join the digital revolution. In this blog, I will explain why it is a good time for the tool industry to adopt the RAIN RFID technology and how to get started.

RAIN is a brand name for passive UHF RFID technology based on GS1 EPC Gen2/ISO 18000-63 standard

RAIN Is Ready

In 2006, IR DSRC defeated RFID technology and was chosen for the Electronic Toll Collection (ETC) System in Taiwan’s freeways. Six years later, in 2012, Taiwan’s ETC system was migrated from IR DSRC to UHF RFID technology, which transferred the freeways tolling system from a flat-rate and barrier-based to a distance-based and multi-lane free-flow on all of Taiwan’s freeways. ETC application is an example of how the market will correct technology selection with time. The tool industry is now facing a similar choice as ETC in 2006. Let’s hope the right technology is chosen from the beginning.

I started to see some companies providing tool management solutions with UHF RFID technology back to 2010. Frankly speaking, I was in doubt at that time if the market would value such a solution. The cost of adding an RFID tag on each tool was not cheap. Also, having a tag recklessly attached or glued on tools seems inappropriate and not professional as the tag protruded on tools’ surface may affect the tool’s usage and cause potential danger to tool users. More importantly, I did not see UHF RFID was ready for tools management in terms of technology maturity then.

Around 2015, Stanley Black & Decker launched tool management solutions aimed at minimizing the effects of FOD (Foreign Object Damage) and ensuring the right tools are in the right places at the right time. This kind of tool management solution is quite attractive in industries like aerospace, transportation, healthcare, manufacturing, and construction. Though barcode is one of the most widely used methods of tools tracking in today’s market, RAIN technology has many advantages over the barcode. For instance, RAIN enabled tools can be read without a direct line of sight even when the tools are covered with dirt or grease. And multiple RAIN enabled tools can be read at once when they are inside a box or bag. RFID Detection Bag is a good use case.

More importantly, more and more tag suppliers are starting to provide RAIN tags for metallic product applications, like industrial tools or surgical tools. Confidex, Omni-ID, Murata, Xerafy, and Etagsys are examples. Some of them can offer customized RAIN tag for the market. This indicates that the RAIN tag industry is ready to serve the tool manufacturing industry.

Built-in RAIN RFID as Part of Product

Using the tools’ metallic surface as an extension of the tag antenna to enhance RAIN RFID read range. A quite high percentage of tools are made of metallic materials, which normally play a negative impact on RAIN RFID performance. The below picture shows a RAIN RFID tag’s (6mmx2mmx2mm) read range when it is measured on air and attached on a metallic surface.

This tag is designed to cover Lower ETSI and FCC bands (865MHz – 930MHz). At the frequency around 920MHz, the tag read range is 0.8 meters when measured on air. If we put the same tag on a 15cm metallic ruler, just like the metallic surface of tools, the read range increases almost 100% to around 1.6 meters.

Tiny RAIN Tag measured on air and metallic surface, 4W EIRP with receiver sensitivity of -75dBm

An innovative tag antenna engineer should think about how to integrate the tag antenna into the tools and turn the challenges of metal into the advantages. Besides, instead of labeling or patching tags on tools after they were produced, embedding RAIN RFID tag into tools in design and production stages not only enables seamless tracking of each tool from the factory to the consumer, but it can also prevent people from removing RAIN tag easily.

Global Regulations

We know different countries have different regulations for RAIN RFID frequency bands. The good news is that Japan had migrated its RAIN RFID frequency band down to 917MHz – 924MHz in 2012. And the European Commission decided to add a new frequency band, Upper ETSI_915MHz – 921MHz, in 2018. By the time of writing this article, about 20 countries in Europe have adopted at least part of the Upper ETSI frequency band for RAIN RFID application. This means that sooner or later, we are going to have a global RAIN RFID frequency band which is allocated around 920MHz. What does it mean for the tool and RAIN RFID industries once the global frequency is widely adopted?

Global frequency simplifies the production of RAIN RFID enabled tools/items. The same RAIN RFID enabled tools can be used and sold worldwide. This will help to scale up production and reduce the cost.

This opens the possibility to optimize tag performance for the narrow frequency band tag around 920MHz. Either tags can be made smaller, or longer read ranges can be achieved, read more from Voyantic CTO Dr. Jesse Tuominen’s blog. Though the variation in the RF performance has a larger impact on read ranges of a narrowband tag than on a broadband tag, fortunately, Voyantic’s Tagsurance UHF has proved to be a great solution in tackling this challenge.

Global standards’ frequency range

No doubt, RAIN RFID provides much superior performance and potential capability compared to the barcode. However, the initial investment of adopting RAIN RFID technology is still more expensive. And it is true that RAIN RFID is not going to replace the barcodes entirely. In some use cases, the combination of RAIN RFID and barcode can be the optimal solution. But I want to point out: after a decade of market development, technology advancement, the cost decrease of RAIN components plus the global regulation change, RAIN RFID is now a feasible solution for the tool industry.

Benefits of RAIN Enabled Tools Management

I recently visited some tool manufacturing companies in Taichung and asked them what are the major problems that the tool users are facing. Their answers include lost, stolen, and misplaced tools. To be honest, I am a little bit surprised by such answers, but it again explains the importance of tool management. RAIN RFID is the ideal solution to reduce the pain points and inefficiencies. From the tool user point of view, RAIN RFID together with other IoT technologies can enhance tool management, for example:

  • Locating and tracking tools become easier
  • Improve security and avoid internal/external thefts
  • Increase tools utilization and availability due to full visibility
  • Minimize the effects of FOD
  • Enhance automation of alerts and reports
  • Eliminate human error and increase management data accuracy
  • Reduce total cost of ownership of tools

The demand for better tool management is apparent, and the market is huge and worldwide. The traditional tool companies surely need to think about how to take this demand as an opportunity and reinvent themselves with RAIN RFID. From my view, tool companies can gain invaluable business advantages if they successfully embrace RAIN RFID into their businesses:

  • Differentiate the product from the competition. This is an especially good opportunity for small and medium-sized tool companies to transform themselves from purely manufacturing to IT-driven business.
  • Sell more higher-value products than tools, for example, smart carry cases, smart drawers, and tools management software.
  • Facilitate sales if the IT system is well designed and developed. Then the customer can check data from smartphone and place order, for instance:
    • Data shows XX2 and XX5 are used over 90% of the time, click here and order both.
    • Data shows XX4 has not been seen in a month, click here and order a new.
  • Every RAIN enabled tool has a unique identification number which can be utilized for anti-counterfeiting and supply chain management from manufacturing to customer.

I am sure there are many more benefits that RAIN RFID can contribute to the tools management applications. I will leave some room for the imagination of the readers. Now let me briefly describe how to implement the RAIN RFID tracking system. There are some possible ways to carry out:

  • Tool company makes the whole solution in-house, including the IT system development and tag antenna design.
  • Tool company outsources RAIN RFID part to several different professional suppliers who provide software development, tag antenna design, and other components independently.
  • Or tool company cooperates with an RFID solution provider to cover all RAIN RFID related tasks.
  • Software company develops and sells tool management solutions to end-users.

It does not matter how the tool management solution is built; the performance and the tuning of RAIN enabled tools need to be carefully tested. Otherwise, the readability would be a big issue. And it is necessary to remind new players that commercial UHF reader is unable to verify RAIN RFID performance. After all, the reader is designed for the application, not for tag design and production quality control. SAG’s story in Taichung Taiwan will explain why it is important to utilize the right testing equipment in the R&D and the production line.

GS1 TIPP

Once the performance of RAIN enabled tools is verified in the actual use case, the tool company can consider applying GS1 TIPP [Tagged-Item Performance Protocol] to streamline RAIN enabled tools specifications. GS1 TIPP is a RAIN RFID grading system developed initially for the supply chain management in retail, but it can be applied outside retail to scale up RAIN RFID applications across industries. Currently, there are fifteen TIPP grades, and tool company can select the grade(s), which can reflect the RAIN enabled tools’ minimal performance requirement. By doing this, it will simplify the communication among tool company, solution provider, and tag supplier. After all, grading is a much more efficient way to define the RAIN enabled tools’ performance. In case the existing grades do not meet the performance requirement, the tool company can submit a new performance grade to GS1 for validation or even create a custom grade.

TIPP Grades or Custom Grades can be used to verify RAIN enabled tools performance

In addition, the tool company can use the grade to source RAIN tag or RAIN enabled tools from several different suppliers if the specified grade level, tag size, and tagging method are met. GS1 TIPP also gives RAIN tag suppliers more flexibility in how they design the tag. This will encourage the tag supplier to be more innovative and creative to design the products to maximize the business benefit. Finally, any company can build its TIPP testing lab based on GS1 guidelines, and operating GS1 TIPP testing is easy and straightforward. This will help the whole tool industry to scale up the deployment of RAIN RFID technology.

Voyantic is the only company in the world specializing in performance testing systems for RAIN RFID and NFC tags from R&D to manufacturing. If you have any questions about managing the quality of RAIN enabled tools, feel free to contact us.

Jun 30, 2020

Adaptive Front-Ends Are Here to Stay

中文版 Chinese version

Impedance Matching

Matching the transponder antenna well to the chip impedance has always been the cornerstone of a well-performing UHF tag. For antenna designers, it is lightly frustrating that each chip brand and model seemed to have their unique impedances, therefore various versions of the same antenna are needed for different chips models.

On the other hand, from the chip designers’ point of view, it must have been frustrating that the tag antenna is never comfortably operating in free space, but always attached to various materials needing different tuning to operate optimally again.

For a long time, it has been known that impedance tuning does not need to be a permanent compromise, but can be actively re-tuned. This has been the norm in many wireless communications and roughly ten years ago this was introduced to UHF RFID as well. The first company to open the game was RFMicron with their ”Chameleon technology” in the Magnus® family of chips.

The early chips had a 5-bit tuning register, giving 32 different and successive tuning states, wherefrom the chip chose the optimal. Since the register value could be read back, the biggest value proved not to be the improved tuning, but the information of how much was tuned. This was turned into a clever way of performing RFID sensoring and later chip versions had an improved resolution of a 9-bit tuning register.

Today, several mainstream RFID chip providers utilize self-adapting front-ends for the small performance gain it provides. Most notable companies utilizing this are Impinj and NXP. Here we are going to see how this alters the tag performance and how to gain visibility into this.

Visibility Into Tuning

First, let’s take a look into the Monza® R6B chip. Examining the memory map in the datasheet, it clearly tells that there are three bits in the reserved memory where you can read the current suggested tuning state. In addition, there is a single bit, by which adaptive tuning can be disabled.

Part of the Monza® R6B datasheet

So, to set the feature on or off in Tagformance® for testing, the simplest way is to perform any write test with the correct write parameters. Reserved memory, Word pointer 4, and write the last bit high/low to deactivate/activate the tuning. The current state can be verified by reading the same memory.

Write parameters for turning the adaptive tuning off. The memory map of the Monza® R6B reserved memory showing the change (in red) where the disable bit was activated. Read parameters to point to the three tuning bits to read back the current tuning state.

Below is a threshold of the tag both with the tuning activated and disabled. With the adaptive tuning activated, the area of optimal performance is seen to increase by +/- 10MHz for this particular inlay design. To monitor the used tuning state, do the sweep with the READ command and the correct read settings for the chip. This gives the ability to select “response data” from the drop-down menu to see what data the chip responded with to the READ. In this case, you can see the tuning goes from 4 to 0 in the ~20MHz stretch from 880MHz to 900MHz.

Sweeping a tag using a READ command while monitoring the tuning state.

How About the UCODE®?

The UCODE® 8 family from NXP works in quite a similar manner. The tuning state can be read back from the memory by pointing to the correct location as stated in the datasheet. The deactivation of the feature needs more involvement. It seems a non-zero access password needs to be set for the tag, and then the setting bit needs to be “toggled” in the secured state using the proper WRITE command as the BLOCKWRITE will not do it. As the UCODE® has fewer tuning steps, you can sometimes spot from the tuning curve the points where the impedance was changed. It’s as if the curve consists of a few cut-n-pasted curves. Well, because it kind of is.

A close-up of a threshold sweep of a UCODE® 8 based label revealing the discrete tuning steps.

Conclusion

Automatically adaptive tag ICs are here to stay. It might be that the advantage they provide is a little slim at the moment, but if there is a performance gain to be had, why not take it? For the antenna designer and tag producer, it is valuable to be able to also switch the tuning off when needed, to easier judge the antenna itself, perhaps against a simulation.

Alternatively monitoring the read response data “stepping diagram” is a simple tool to see if the design is functioning as it should. Eager to chat more about tag design with us? Feel free to contact our RFID experts HERE.

Oct 29, 2018

The ETSI Upper Band Has Arrived! What Happens Then?

中文版 Chinese version

The October 11th 2018 was a day of small celebration in the RFID industry. Celebration, because on that date, the European Commission published their positive implementing decision about the 915-921 MHz frequency band in Europe. Small, because it came out as somewhat of a compromise in the end allowing less than anticipated new channels, and in coexistence with other IoT and short range devices. This was referred to as the squeeze plan. The given implementation deadline is the 1st of February, 2019, so in a few months, country by country, the new band will become a reality.

Global Tags

Now that there is a more or less global frequency band in the world allocated for RAIN RFID, it is possible to design tags that can be operated around the world. For basic labels and average sized hard and on-metal tags this has not been an issue in the past either. It isn’t too hard at all to stretch the tag’s performance band to cover both the 865-867 MHz and 902-928 MHz bands in one go with giving practically no performance away in the process.

Smaller tags tend to be specific for a frequency band, whereas larger labels are easily truly global.

Miniaturization of tags, like the ones needed to track small tools and surgical equipment, as an example, has come with a cost. It’s near impossible to make a tag which is simultaneously: (1) small, (2) wideband and (3) has a good performance. Pick any two qualities and say farewell to the third. With the miniaturized RAIN tags, the lost quality has predominantly been the wide bandwidth. This has led to separate tag versions for the ETSI 866 MHz region and for the 902-928 MHz FCC band. The very smallest tags have even had trouble covering the whole FCC band. Luckily, there is the obligatory frequency hopping to cover this deficit. Now, making a global miniaturized tag is easy, just aim at the 917 MHz mark and be done.

A New Breed of Readers

In all likelihood, we are going to witness the emerging of a new breed of RAIN readers as well. A truly global reader would be nice, and will surely arrive one day. Long before that, we need a new spec ETSI reader, one that will operate both on the European lower and upper band. The utilization of the two bands will help better cover all tags, especially all those miniaturized tags, tags with close-coupling issues and large challenging populations. The utilization of both the bands interleaved might also give rise to features, like more accurate tag ranging and positioning.

From a hardware point of view, there lies a small re-design challenge. Most of the smaller inbuilt circular antennas in the hand-held readers are certainly unique to ETSI or FCC currently and need some tweaking to cover both bands with a good performance. Other hardware like directional couplers, SAW filters, and power amplifier matching might also not be directly functional for both bands. While these are fairly simple RF engineering tasks to put right, it means that a big portion of the existing readers probably are not updateable to the new European RF landscape with a simple firmware update.

Different Flavors of the Upper Band

When we look closer into the requirements at different regions that use the upper band, we start to notice a lot more differences to which the readers need to adapt. The first thing that will catch attention is the sheer difference in the number of channels available in the bands such as FCC and Brazil as an example. After that one would hope that the three allocated ETSI upper band channels would be ones picked from the FCC channel, but actually none of them coincide. Same goes for Chinese, Japanese, Russian and other channels, they just are not the same. Also, the center frequencies often do not give much of a room for flexibility. For instance, ETSI specifies a channel center frequency maximum deviation of 10ppm, which equates to +/- 9.2kHz. So, for example, there is no compromise available to be at for the nearly coinciding channels of 916.3 MHz (ETSI) and 916.25 MHz (FCC) simultaneously.

To add to the complexity, different regions have varying regulations of:

  • channel hopping
  • dwell time
  • Listen before Talk (LBT)
  • sensitivity limit
  • modulation speeds and formats (because of spectral mask).

At the moment all of this is not a huge technical hurdle to accomplish. But the day will come when readers start to cross borders installed in cars, trains and even operating in mobile phones, and then it will be a major inconvenience to track location and change settings at every border.

Channel center frequencies in various regions. Most use their own list of frequencies which just do not coincide.

Summary

The coming changes in the Europe and the already existing different RAIN RFID bands in the world have long affected the tag design. The new ETSI upper band is a move to the right direction to make RFID systems more global. This will give the reader manufacturers a lot of thinking and rework for the months to come – the outcome of which will be interesting to see. The two different European bands will start to co-exist and readers have one more set of channels and regulations to adapt to.

Luckily when it comes to the minor channel frequency differences in the upper band, at least the tags don’t mind.

Mar 09, 2018

Connections Summit Brings RAIN RFID, NFC, and AIDC Together

中文版 Chinese version

Until now, it has seemed that different RFID and AIDC technologies, as well as the organizations that represent them have resided in their own silos. Both RAIN RFID and NFC have been focusing on their own applications and they don’t seem to have much in common. At the same time, both technologies have been quite distant from all the discussion surrounding the Internet of Things (IoT).

But as a matter of fact, the two technologies have a common goal: they strive to be means for connecting items to the cloud. And the technologies don’t really compete against each other. So, it makes perfect sense that the two industries started to pull into one direction. That is why the RAIN RFID Alliance, the NFC Forum and AIM Global joined forces to arrange the first Connections Summit at the Google campus in Sunnyvale, California.

Connections Summit 2018 Attracted Excellent Attendance

The Connections Summit brought together the RAIN RFID and NFC communities, as well as a lot of curious visitors, into a day full of presentations and panels that covered various aspects of these technologies. Overall, there were over 450 people participating, which I think is a huge success. The presentations covered the host Google’s view of the IoT, IDTechEx’s market information, and numerous case studies highlighting the use of both NFC and RAIN RFID. It was clear that RAIN RFID, NFC, BLE (Bluetooth Low-Energy) and other wireless technologies, as well as optical codes have their own benefits and uses. There are some overlaps, but the overlapping application areas are shadowed by unique benefits of each technology.

Intranets of Things is not True IoT

Even if each data collecting technology has its own benefits, there are also shared development needs in the broader identification and IoT industry. In many presentations and discussions, the questions related to the collected data. There is a clear need for common standards on how to point the ID codes to actual data in the cloud (the digital twin). Currently, each technology relies on different methods and standards, and in many cases, applications are company-specific. The current Internet of Things (IoT) is actually a number of separate intranets of things, offering very little meaningful IoT data available “in the internet”.

Data Sharing Requires Determining of Ownership and Privacy

In order to move from the intranets to real IoT, data sharing standards are needed. The topic is complicated: In addition to pure standardization, also questions of privacy and data ownership have to be addressed. What part of the data is owned by the owner of the item? What is owned by the organization collecting the data? And who owns the data that is aggregated from multiple sources? The discussion has started, but the IoT industry has a long road ahead before all these questions are solved.

So, what is the verdict? Did the event work out? Yes! There was definitely a need for this kind of cross-pollination. Everyone I talked to at the event emphasized that they had learned a lot. I am sure that this event was not the last of its kind, I am looking forward to the next one.

Jun 02, 2017

RFID Journal Live in Phoenix – The New Exciting Stuff Was in IEEE RFID

中文版 Chinese version

This year’s RFID Journal Live! was arranged in Phoenix, AZ three weeks ago. I have been scanning through different reports about the show, and they all seem to amplify my own perception: the overall business was good, things are moving forward, but there was nothing particularly new and exciting this time. Sure, the inventory robots were still there, readers are integrating with antennas, and some new chips were announced, but that’s about it.

So, instead of writing about Journal Live!, this year I am focusing my show report on a co-located event that always delivers something new, the IEEE RFID conference. The conference was arranged for the 11th time, and I think I have only missed it once – though often I have had to divide my time between IEEE and the trade show.

The conference featured two excellent key-note presentations: Secure RFID for Trusting Devices and Data by René Martinez of Honeywell and Near-Zero Power Radio Frequency Receivers by Troy Olsson of DARPA. And then there were a total of 32 technical papers presented. Most papers were accepted in these categories:

  • Localization
  • Protocols and Security
  • Antennas and Propagation
  • Circuits, Devices and Readers

So, it seems that localization is on the rise, as the category has reached the top from outside the top-5 of 2016 event. I haven’t really seen asset localization properly break through in the industry, but I wouldn’t be surprised if it did in the near future.

Poster Session

During the last few years, IEEE RFID has arranged a poster session in the RFID Journal Live! exhibition area. So, if you do one thing to learn about what is going on in the research space, I recommend browsing through the poster area. In just half an hour you will get a nice overview of the latest research related to circuits, protocols, antennas, chipless sensors, etc. This year, there were a total of 25 posters from universities around the world, but also one from the industry: the French company Primo1D had a poster about their RFID yarn. A full list of poster titles can be found here.

This year, I was privileged to be a member of an expert panel that was assigned to choose the best poster. It took us two hours of looking through the posters, interviewing the presenters, and discussing, until we were able to decide the winner:

“A Dual-Band Wireless Power Transfer and Backscatter Communication Approach for Implantable Neuroprosthetic Devices” by Eleftherios Kampianakis and Apoorva Sharma (University of Washington, USA); Jose Arenas (University of Washington, Chile); Matthew Reynolds (University of Washington, USA).

The presented research combines UHF and HF RFID, as well as many disciplines of electronics and RF engineering into an implantable neuroprosthetic testbed. A more detailed description can be found here.

Best Paper Award

This year’s best paper award went to Pavel Nikitin of Honeywell for his paper titled ‘Self-Reconfigurable RFID Reader Antenna’. The paper presents a method for varying the beam of an antenna. The method is presented with a two-element Yagi antenna, where the parasitic element is loaded with a self-oscillating circuit. The ability to change the reader beam could be especially useful when inventorying static tag populations, e.g. when using an overhead reader to inventory a retail store.

But what pleased me most, was that some of the measurement data in Pavel’s paper was generated with the Voyantic Tagformance Pro system. Let me explain why.

This is me and my colleague Jesse back in 2006, sitting in front of the very first Tagformance prototype. We had just left our jobs at the university, and were frantically trying to build a system for testing the performance of UHF RFID tags. I spent hours of trying to understand papers written by Pavel Nikitin – then only a name to me. And we were able to pull it off: we got our system out to the market for RFID World 2007 which, by the way, was co-located with the very first IEEE RFID conference. Now, seeing our system used in one of Pavel’s papers 11 years later feels like the circle is closed.

Apr 27, 2017

Four Factors That Make Japan the Perfect Place to Deploy RAIN RFID in Convenience Stores

中文版 Chinese version

The Nikkei Asian Review released a story about how some of the largest Japanese convenience stores plan to deploy RFID as a fix to severe labor shortage. Firstly, I am personally a huge fan of Japan and secondly, I’ve done quite a bit of work to speed up RAIN RFID deployments in the retail market. Still this announcement from Japan took me by surprise, and let me explain why.

Nikkei Asian Review: New RFID self-checkout systems will eliminate the need to scan each item individually, helping to cope with a severe lack of manpower.

Unconventional Motivation

This is the first time I’ve heard labor shortage to drive the RFID deployment. In Europe and the USA it’s been more about omni-channel sales that creates sales uplift, and all the efficiencies that simply result from high inventory accuracy.

Still, as you give it a moment to sink in, isn’t this just perfect news – labor shortage as a new driver has emerged and greatly motivates several large stakeholders to engage in this initiative, including Seven-Eleven, Lawson, Familymart and even the Japanese Ministry of Economy, Trade and Industry!

For me Japan is the most intriguing piece of the plot, and let me outline the four factors that I believe will help this initiative all the way to success:

Factor #1: Collective Efficiency in Their Veins

The culture enables the Japanese to behave and act highly efficiently in extremely large and dense crowds. If a new form of practice is available to improve public efficiencies, the Japanese are the first ones to oblige.

Consider the notorious train rush every morning between 8AM and 9AM. The Yamanote Line, for example, is an amazing experience. With a ridership of over 1,000,000 passengers overcrowding is both a challenge and a fact. Keep to the left and go with the flow, yes, but there is more to the story.

Factor #2: Payment Cards as the Sixth Finger

You can’t get around in Tokyo without a Suica® or a Pasmo® card. Based on the Sony FeliCa® technology, these rechargeable payment cards enable the commuters to quickly pass through the ticket gates at the JR and Subway stations, and help maintain the efficient flow of people in the jampacked station platforms.

You can conveniently use the same payment cards for many of the small purchases you stumble around the stations. As you take a moment with it, actually kiosks, taxis, cafes and many other small businesses seem to even endorse Suica® over coins.

Factor #3: Ubiquitous Automation

For the sake of efficiency and convenience, a metropol such as Tokyo is filled with automation to assist the consumers. I’d especially highlight the vending machines that you can find around in corridors and even on the station platforms. Take the automated ordering systems at fast-food restaurants as the second example. Automation and advanced user experience even follow the average Haruto-san all the way to the restrooms as well.

Factor #4: Local Retail Technology Vendors

If one has ever visited the RetailTech Exhibition in Tokyo Big Sight, it is pretty clear for a Japanese retailer that there are many Japanese based top brands to choose the implementer partner from: Toshiba TEC, Sato, Fujitsu, NCR, Ricoh…. On top of that, there is a great number of local experienced RFID label solutions providers, such as FVG, Sato, Toppan Forms, Toppan Printing, and Fine Label to name a few. Altech provides expertise and solutions related to RFID label testing and manufacturing.

A local partner is a great asset for clearing obstacles and moving any project forward at a fast pace.

A Few Ideas to Support Success

As a few generations of Japanese consumers are native to utilizing payment cards and automation in their everyday life, the RFID based self-checkouts at convenience stores should be nothing new. The local ecosystem of RAIN RFID vendors already exists, so I would only list two long-term implementation success factors to closely consider by all the stakeholders:
1. Utilize EPC numbering for the tagged sale items, because proprietary item numbering systems overlap sooner or later and then erode the RFID system reliability
2. Utilize the GS1 TIPP Guideline to specify the tagged item performance requirements, because TIPP makes the deployment more future-proof and enables the suppliers to manage tagging economically.

Voyantic provides easy-to-use turn-key solutions for TIPP testing.

With this said, I hope all goes well with the initiative. Please drop me a line if you’d like to raise further conversation around the topic!

SUICA is a registered trademark of East Japan Railway Company
PASMO is a registered trademark of PASMO Co., Ltd.
FeliCa is a registered trademark of Sony Corporation

Oct 07, 2016

Recommendation for RFID Reader Testing from RAIN RFID Alliance

中文版 Chinese version

The RAIN RFID Alliance recently published a recommendation for RFID reader sensitivity testing. But why is such a recommendation important for the RFID industry? I was deeply involved in its creation process, and can open up some of the reasoning behind it.

Reader Sensitivity Is Important

It is well known that the performance of a RAIN RFID system depends on

  • reader transmit power,
  • the path loss between the tag and the reader,
  • tag sensitivity,
  • tag backscatter power, and
  • reader sensitivity.

Now there is plenty of information available about tag performance, and tags are typically characterized in detail both in the design phase as well as in production. Measuring path loss (characterizing the environment) is relatively easy as well – simply measure a Voyantic Reference Tag with the Tagformance system in an unknown environment, and the result is the path loss between the reader and the tag (contact Voyantic for more information about the test process). But even though reader sensitivity is one of the main elements defining the overall performance of a RAIN RFID system, it has been given very little emphasis so far.

RAIN RFID Alliance Reader Sensitivity Test Recommendation

Almost all RFID reader datasheets report output power (TX power, radiated power, port power) somehow, but very few reader manufacturers report the receiver sensitivity of their reader. And without the sensitivity information, you can’t really be confident about the reliability of your RFID system. So RAIN RFID Alliance decided to take the initiative and publish a recommendation document “RAIN RFID Reader Sensitivity Testing” to get more companies to report their reader sensitivity.

Now reader sensitivity can be a complicated issue, but only if you let it.

It is well known that sensitivity varies (a little) as a function of the exact frequency, reader transmit power, and the choice of protocol parameters. However, the RAIN RFID Alliance workgroup that developed the recommendation, opted for simplicity and deemed sufficient to report a single sensitivity value. In order to make comparing reported sensitivity values easy, it was also required to report the used test parameters. As a result, RFID system integrators and end users can evaluate the usefulness of the sensitivity data by comparing the test parameters to those of their use case. And if needed, they can request further test data with other parameters.

Voyantic Readformance Reader Tester

Voyantic Readformance – Perfect Match with the RAIN RFID Alliance Recommendation

Voyantic has offered a solution for reader sensitivity testing, the Readformance, for several years. So with our experience in reader testing, it was natural for us to participate in developing the RAIN RFID Alliance test recommendation.

The approach taken in the recommendation was:

Easy and simple testing that anyone can perform without the most expensive test equipment.

This very same approach, combining simplicity and flexibility with fast and low cost testing, is exactly what we had in mind when designing the Readformance back in 2012.

In order to help the RFID industry, and to boost availability of reader sensitivity information, Voyantic is also offering reader sensitivity testing as a service, in addition to selling test equipment. Request a quotation for reader sensitivity testing!

Reader testing performed at the Voyantic lab

Learn How to Test RAIN RFID Reader Performance

Download our application note “Testing RAIN RFID Reader Performance with Voyantic Readformance” to learn how easy it is to test the sensitivity of a reader!

Aug 11, 2016

RAIN RFID, UHF RFID, EPC RFID, … – Confused by the Different Names?

中文版 Chinese version

I am frequently lecturing to RFID users and technology providers about quality and performance in RFID. Every now and then a question about the terminology comes up. RFID technology has developed through several paths and as a result there are a lot of names and definitions for RFID. A beloved child has many names, says a Finnish proverb. Understanding the different points of view in naming and the origins of the terminology help to understand the many names.

RFID and Frequency

RFID – Radio Frequency IDentification – is the umbrella term covering a wide variety of technologies: frequencies, communication protocols, and device types. One common way to refer to the different technologies is with the names of the frequency bands:

  • LF RFID (Low Frequency RFID)
    125 kHz – 134.2 kHz, 125 kHz RFID, 134 kHz RFID
  • HF RFID (High Frequency RFID)
    13.553 MHz – 13.567 MHz, 13.56 MHz RFID
  • UHF RFID (Ultra High Frequency RFID)
    433 MHz: 433 MHz RFID
    858 MHz – 960 MHz: UHF RFID *)
  • Microwave RFID
    2.4 GHz – 2.454 GHz: 2.4 GHz RFID
    5.725 GHz – 5.875 GHz: 5.8 GHz RFID

*) Includes local bands ETSI RFID (865 MHz – 868 MHz) and FCC RFID or 915 MHz RFID (902 MHz -928 MHz)

Passive and Active RFID

Different RFID technologies feature different ways to power up the tags and to communicate between the reader and the tag. The base technology is used as one way to classify RFID:

  • Passive RFID: technology where the tag powers up from the radio frequency energy sent by the reader, and communicates back by modulating the reader signal
  • Battery assisted passive RFID, BAP RFID, Semi-passive RFID: technology where the tag gets its operating power from a battery but communicates back by modulating the reader signal
  • Active RFID: technology where the RFID tag is powered from a battery and communicates by active transmission
  • RFID sensor, sensor tag: a sensor (temperature, pressure, humidity – or anything else) is integrated into the RFID tag – can be passive, active or BAP
  • Chipless RFID: tags without a silicon microchip based on time-domain reflectometry or frequency signature techniques are called chipless RFID tags.

RFID Names from Standards

Another approach for RFID naming comes from the radio transmission protocols. They are described in radio protocol standards, and are often referred to by the standard names: ISO 15693, ISO 14443-A, ISO 14443-B, ISO 18000-62, ISO 18000-63, GB T/29768

The alphanumeric standard names are not that good for marketing use, so many of the standards are more widely known by commercial brand names, such as

  • Mifare: NXP’s trademark for 13.56 MHz, ISO 14443-A
  • FeliCa: Sony’s trademark for 13.56 MHz, JIS X 6319-4
  • EPC RFID: Electronic Product Code, GS1’s standard family for data content in RFID, standard family includes also protocol standards and frequency standards – also standardized as ISO 18000-63 (formerly ISO 18000-6C)
  • SINIAV: (Sistema de Identificação Automática de Veículos) Brasilian department of transportation’s system for identifying cars. The system includes also RFID protocol standard at UHF RFID frequency

Many of the standards have also been published by various organizations with no or with small adjustments. For example, it is common that a standard is published as a national standard (JIS, DIN,…) , or industry specific standard (IEC for example) and afterwards as a global ISO standard.

Marketing Names and Industry Organizations Aiming for Clarification

In order to fully describe a specific technology, several of the above names can (and sometimes must) be used together. For example: Passive 13.56MHz sensor tag with ISO 15693 protocol. Also several names are interrelated – for example ISO14443-A is in practice always also 13.56 MHz (HF RFID), and passive.

Using these technology derived names and standard names for describing the technology can be complicated, confusing, and in many cases drives the focus to the wrong direction. Industry organizations have recognized this problem and they have launched marketing names for most common technology combinations. Their focus is on the use cases instead of technical details and their goal is that these names would become the everyday names for RFID technologies – just like e.g. Bluetooth has become a common name for radio communication between electronics devices using 2.4 GHz frequency and ISO 802.15 standard protocol.

  • NFC: Near Field Communication is a term/brand by an industry organization (link: http://nfc-forum.org/ text: NFC Forum popup:yes). The term describes a main stream combination of HF RFID technologies, and is used extensively in e.g. smart phones. The technology uses 13.56 MHz frequency and several protocols, such as ISO14443A, ISO14443B, and FeliCa (Japan Standard JIS X 6319-4).

  • RAIN RFID: RAIN RFID is a name coined by the RAIN RFID Alliance – a global cooperation organization of companies offering or utilizing passive UHF RFID. The RAIN RFID covers RFID technologies using frequencies from 860 MHz to 960 MHz and the EPC RFID Gen2 protocol, also known as ISO 18000-63 air interface, regardless of the used numbering system.

Which Names Should Be Used?

I am not ready to trash any of the current terminology. However, I have my own preferences.
I prefer the NFC and RAIN RFID terms in case studies and similar documents aimed for a wider audience when not focusing on nitty-gritty technical details but describing benefits of the technology.

When the focus is on certain technical viewpoints: protocol, frequency, technology type etc., I prefer the narrow technical terms. “Computer accessory for reading battery assisted UHF RFID EPC temperature sensor tags” sounds horrible, but actually describes quite well the technology solutions used. For a consumer the monster-term is not as easy as having a RAIN RFID enabled laptop.

Voyantic is a quality and performance test system provider for the RFID industry. The test systems can be used for testing tags and readers at UHF and HF RFID frequencies – or if you prefer – within RAIN RFID and NFC.

Jul 08, 2016

Downgrading Your Spec Does Not Make a Quality Tag – Thoughts About RFID Quality

中文版 Chinese version

I work as the CEO of Voyantic, a company that specializes in RFID test and measurement equipment. Since our systems are used by hundreds of companies around the world, we often come across cases where a customer needs our help to verify that their tags work as they should. This is a story about a case where things went wrong.

Tagging Athletes in Cross-country Skiing

We got involved with a very interesting case a couple of years ago. A small RFID integrator that we have known for some time wanted to tag athletes in a cross-country skiing competition. The idea was to use RFID for timing the race. And you can guess that if someone spends several hours on the ski track, being left without a race time is definitely not an option.

Cross-country skiing is a healthy hobby and also a good application for RFID timing – Photo by Sorbis / Shutterstock.com

There are many different ways to tag athletes in timing solutions. Common approaches in running competitions include integrating the RFID tags to the race bibs or attaching them to the shoes of the runners. However, in this case, the chosen approach was to buy wrist-band tags and to attach them to the ankles of the skiers. The tags were read by fixed readers that were set up on the side of the tracks.

The integrator went through the specifications of several different wrist-band tags and finally contacted a fairly well known maker of specialty tags for some samples. The samples arrived the following week, and the integrator ran some field tests. Everything worked well. He was able to detect every skier that passed the reader antenna.

So the integrator decided to order the tags that he needed for his application. Once again, there was a timely delivery of correct amount of tags. However, when he started to build the application, he noticed that not all of the tags were working. A typical discussion between an unsatisfied customer and a worried supplier followed.

The conclusion was that all the supplied tags worked according to the specification.

The tag manufacturer tested both working and non-working tags attached to the wrist of whoever they considered to be their standard-human. All tags were readable from a distance of 2 m which was the specification. But they didn’t all work in the end application. How is this possible?

Analysis

We got involved with the case at this point. We were asked to take a look at the tag samples to try to understand what was going on. So we ran a performance test for the tags using the Tagformance measurement system. The results from the Threshold Sweep measurement are shown below.

Performance variations of wrist-band UHF RFID tags measured with the Tagformance system

We tested the tags in free air, so they were not attached to a wrist or an ankle. But even in this setup it is clearly visible that there are significant variations in the tuning and performance of the tags. So this is what we think happened:

  1. The integrator decided to use the tags differently from what the manufacturer had specified
  2. The first samples sent by the tag manufacturer performed clearly above the spec
  3. The integrator concluded that this tag will work in the application
  4. The next tag batch – even though still within the original spec – performed differently
  5. A part of the tags didn’t work.

So, it is very hard to point fingers in this case. But there is something that the RFID industry needs to improve in. The industry is already doing a decent job in reporting the performance of their tags, e.g. in expected read range. But I think there is a lot to improve in how performance variations are reported, because that is a key factor in building reliable RFID systems.

And what happened with the skiing competition? Did the integrator get the system to work? He did. But he had to manually test through the tags and hand-pick the ones that worked well enough. Hardly a perfect outcome but every skier got their time.

My company Voyantic specializes in test and measurement solutions for the RFID industry. Are you interested to learn more about RFID quality control? Download our sample quality test report and contact us.

Download the Sample Quality Test Report!

See what performance testing can tell you about a tag – and how this data can be used to improve your production quality