RFID: Tag, You’re It!
By Lynda Nolen, Bishop & Associates Inc.

Seven years ago, Wal-Mart, the world’s largest retailer, made an announcement that would forever change the world of radio frequency (RF). Beginning January 1, 2005, Wal-Mart would require their top 100 suppliers to deliver all pallets and cases furnished with electronic product codes (EPCs), also referred to as RFID tags or transponders.

The company’s intent was to better manage and track its supply chain, although they admitted initially that they would not track all of the shipments from the top 100—one billion cases a year from these suppliers. At the time, they did not fully understand the vast amount of data that could be captured using these devices or know how they would use this information. They did know that the use of RFID in retail was inevitable. RFID devices have changed many other aspects of our lives, too.

The idea of tracking inventory or assets through the use of an electronic product identification code is nothing new. Although initially geared towards the grocery store market, to monitor the vast number of products and high inventory turns typical of this market, product identification codes have been around since the 1940s. One of the earliest uses of electronic product identification codes was seen in the rail industry, where Sylvania Corporation developed a method using a light scanner and reflective strips adhered to railcars to monitor movement to and from the yard. Unfortunately, at that time, the cost of the scanning equipment, as well as the size of the scanners, made it prohibitive for most companies. Another interesting use of RFID was seen during World War II, when the British attached a transmitter to their planes, which allowed them to use their existing radar to distinguish friend from foe.

During the 1960s and ’70s, work continued in the field of product identification, with barcodes, transponders, and antennas benefiting from technology advances and perseverance. Reductions in the cost of transistors and the modification of codes and imprint materials allowed electronic product identification to flourish, especially in the retail industry. In the early 1970s, based on a code developed by Logicon Inc., the Universal Grocery Products Identification Code or UGPIC, which later evolved into the Universal Product Code (UPC), was put to the test with the installation of the first UPC scanner in a supermarket in Troy, Ohio. Unlike earlier barcodes, which were shaped like a “bulls eye” and required the use of high wattage incandescent bulbs to “read” their information, these bar codes were vertical and relied on a laser beam to read them.

The advantages such a system offered became immediately evident, and it wasn’t long before the UPC concept gained attention in other countries and similar systems were developed. In Europe, the European Article Numbering System (EAN) was developed; in Japan, the Japanese Article Number system (JAN); and eventually the International Article Number system (IAN). All of these codes were similar in concept to the UPC, with a variation on the number of digits. Later, to accommodate individual industries or applications, other codes, such as the International Standard Book Number System (ISBN), which is used to identify books, and Code 39, which is used in manufacturing, health care, and government, were also developed.

Although barcodes, and later, magnetic strips as found on credit cards, proved to be a valuable asset, the use of barcodes and strips did have limitations. For instance, in order to work properly, the barcode must be positioned relative to the scanner—generally within inches. In the case of a magnetic strip, a user must manually swipe the card through a specifically designed machine. Also, as many of us have witnessed, barcodes and strips must be individually scanned, a process that is normally performed manually. There are also limits on the amount of information that can be stored and obtained through a barcode; it’s usually limited to identifying the type of item, but not the individual attributes of that item. The solution to all of these limitations could be solved by the use of RFID, but until recently, the cost of implementation, in particular the cost of the tags and associated equipment, limited widespread adoption.

The RFID System
An RFID system is composed of three primary components: an RFID antenna, an RFID tag or integrated circuit chip (the transponder), and an RFID transceiver or reader. RFID tags or transponders are generally classified as active, indicating they supply their own power, generally through the use of a battery, or passive, indicating they require an external power source to operate.

To lengthen the life of active RFID tags, a third type has been developed: battery-assisted passive RFID tags. Tags or transponders are classified in two additional manners. The first is based on the operating frequency. Ultra-high-frequency (UHF) RFID tags generally operate in the 850 MHz (Europe) to 950 MHz (U.S.) range, while low-frequency and high-frequency tags generally operate around 125 KHz and 13.56 MHz, respectively. Although used only in specific applications, microwave RFID tags are available and generally operate in the 2.4 GHz to 2.5 GHz range.

The second manner involves the ability to add or alter stored information. In read-only tags, the information on the tag is permanently encoded during manufacturing. In read-write tags, a portion of the information is permanently encoded during manufacturing, but additional information can be added by the user.



Motorola’s XR450 Fixed RFID Reader includes USB, RJ45, and D-subminiature external connections, as well as eight reverse TNC connectors. Operating at 902 to 928 MHz, this UHF band reader operates effectively in a controlled atmosphere. Enclosed in a NEMA enclosure, it can operate in harshest environments.




 

Similar to tags and transceivers or readers, RFID antennas come in a variety of frequency ranges, sizes, and styles—all designed around parameters such as beam width, gain, power, and application. These parameters also dictate RF connector type and style. An example of this can be seen in HUBER+SUHNER’s broad range of RFID antennas for industrial and rail applications. Their IP69K-rated, omni-directional Sencity™ Rail Antenna is offered in six different frequency ranges, covering 380 MHz to 5935 MHz, and is connected via a female N-type connector located on the bottom of the antenna. Because of the application, this antenna also complies with special railway standards, such as protection against electrical short circuits and isolation, in case of a rupture of overhead lines. Their Sencity two-directional antenna, designed specifically for forklift applications, operates from 865 to 928 MHz and is connected using a female QMA connector located on the back of the antenna. Their Sencity Antenna for short-reading distances also utilizes a female SMA connector.

RFID tags or transponders have undergone dramatic changes over the last five years. Tags, which are basically a copper-wire antenna attached to an integrated circuit chip, can be encapsulated in a variety of mediums. Size is generally based on whether the tag is active—meaning it contains some type of battery—or passive, meaning power is created by the electromagnetic field generated by the antenna. Size and composition are also determined by application. Although both have their advantages, passives are generally cheaper, but have greater distant limitations than active. Passive tags also have spatial limitations, meaning they don’t transmit easily through walls and metal can cause interference problems. To reduce battery usage, many active tags are equipped with accelerometers that put them in a sleep mode when activity is not sensed.

RFID tags encapsulated in glass are what are used in animal tracking and identification systems. Glass encapsulated tags are also used in automobile immobilizer systems and asset tracking and identification systems. For applications where environmental factors play a prevalent role, RFID disc tags encapsulated in PVC, PET, or another substrate, provide a waterproof tag that is impervious to a variety of chemicals and can handle extreme levels of shock and vibration. Disc tags also lend themselves nicely to further assembly and are used heavily in the pharmaceutical, food processing, and medical industries. In applications where an RFID tag must be mounted directly to a stillage or trolley, tags can be molded into modified housings that allow them to function properly when placed on or near liquid or metallic objects.

In addition to reducing theft and inventory shrinkage, another important area of use for RFID is in the reduction in counterfeiting opportunities.

Expanded Role of RFID
Although RFID devices have been used successfully in the medical industry for years, an aspect of that industry that is still in its infancy stage is the implanting of RFID tags in humans. Geared at providing quick and accurate information on an individual’s identity, medical history, or other pertinent data, RFID chips for human implantation were approved by the FDA in 2004. Although many Americans and Europeans are skeptical, this has not prevented other countries from embedding chips in humans already. Mexico currently embeds chips in government employees working at the attorney general’s office. Other potential medical applications currently in development include implantable chips that would measure a diabetic person’s glucose level in real-time and send an immediate message to correct an unstable sugar level.

The most interesting aspect of RFID technology is that most of us are not even aware of the numerous ways our activities and personal information are already being tracked. Any U.S. passport issued after 2007 carries an RFID tag, as well as many foreign-issued passports. The toll tag mounted onto your vehicle’s window provides detailed information, via an RFID tag, about the exact time and date your vehicle passed through a particular location. Many states offer RFID tags embedded in drivers’ licenses, while others, like Oklahoma, are attempting to pass laws prohibiting the use of RFID technology on drivers’ licenses.

If you have checked out a library book recently, or even eaten a hamburger, more than likely the use of RFID technology has been involved. Others areas where RFID tags have been customarily used include security badges, access control at amusement parks, swimming areas, or fitness centers, and government management of equipment in the field.

Future Applications
One of the most significant advancements in RFID technology has been in the area of asset management, and in particular, the use of RFID tags to replace bar coding. Earlier this year, researchers at Rice University in Houston, Texas, developed a process to print passive RFID labels directly on consumer-purchased packages. Using ink laced with carbon nanotubes, the process would allow shoppers to literally pass their shopping carts by a reader and have all of their items instantly scanned and charged to their credit card as they walk to their car. Currently, it is estimated that the tags would run about three cents apiece, but researchers are working on improving the process, in particular the cost of producing the carbon nanotubes, with the aim of bringing the price closer to a penny a piece.

Developing better and more efficient ways of producing carbon nanotubes will not only benefit those involved in the development of printable passive RFID labels, but could also, potentially, affect the overall design of connectors. Offering a structural composition that is 100 times stronger than steel, yet one-sixth the weight, the development of a lightweight, electrical wire- and- cable system incorporating carbon nanotubes for aerospace applications is currently being designed. Because carbon nanotubes are highly conductive (100 times that of copper), many interconnect manufacturers, including Molex and Tyco Electronics, are also looking at ways to incorporate carbon nanotubes into applications where weight and thermal properties play a signification role.

Other areas in which RFID usage is expected to achieve double-digit growth is in transportation security. Last month, Quantas Airlines began a test program where frequent flyer members are issued a touch-card embedded with an RFID tag that will allow them to check in for flights. This card will also allow them to check their baggage, and provide them with a unique RFID tag receipt containing the same information as their touch-card. RFID tags are also being used in Europe to monitor the movement of trucks and cargo. RFID tags attached to trailer doors can continually monitor the location of the truck and can also notify custom officials if the doors have been opened without authorization.

Summary
Whether you feel comfortable with it or not, RFID technology is here to stay. According to ABI Research, the five-year CAGR (2009 – 2014) for the RFID market—excluding one of the largest markets, automobile immobilization—is currently projected at 14 percent. While today, over 50 percent of RFID usage is geared towards applications such as toll collection and access control, projected growth for these is expected to remain in the single digits, while more advanced applications, such as human, animal, and inventory tracking, POS contact-less payment systems, and asset management systems, are expected to have a five-year CAGR of just under 20 percent.

Although Wal-Mart may have been the original driving force behind the rapid growth of RFID technology, it is interesting to note that even today, many suppliers to the world’s largest retail chain still have not fully deployed the technology, nor has Wal-Mart followed through with their original compliance requirements. For many, particularly small companies, costs in equipment (readers, tags, and software) and training have been a major issue. For others, the early lack of standards created a sense of uncertainty and also thwarted many initial attempts to implement the technology. With the cost of tags dropping annually, improvements and availability of antenna and transceiver/reader equipment, and the implementation of more defined standards, it may not be long before RFID technology becomes second nature to even the smallest of companies.

Lynda Nolen Product Specialist, Bishop & Associates Inc. Lynda Nolen has been in the interconnect industry for over 30 years. She has worked in sales, sales management, marketing, and product management for such companies as TRW Electronics Components Group, Sunbelt Components, Cinch Connectors, Arrow Electronics, PEI Genesis, and Delphi Interconnect. Nolen has extensive experience in competitive cross-referencing, drawing, web and catalog review, new product introduction programs, harness and connector assembly programs, account management, and customer service programs. Lynda received her Bachelor of Arts degree from Roger Williams University in Rhode Island in 1979, and has completed various electrical engineering courses.