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What is RFID?

Radio frequency identification, or RFID, is a generic term for technologies that use radio waves to automatically identify people or objects. There are several methods of identification, but the most common is to store a serial number that identifies a person or object, and perhaps other information, on a microchip that is attached to an antenna (the chip and the antenna together are called an RFID transponder or an RFID inlay). The antenna enables the chip to transmit the identification information to a reader. The reader converts the radio waves reflected back from the RFID tag into digital information that can then be passed on to computers that can make use of it.

How does an RFID system work?

An RFID system may consist of several components including tags, tag readers, edge servers, middleware, and application software.

The purpose of an RFID system is to enable data to be transmitted by a mobile device, called a Tag, which is read by an RFID reader and processed according to the needs of a particular application. The data transmitted by the tag may provide identification or location information, or specifics about the product tagged, such as price, color, date of purchase, etc.

In a typical RFID system, individual objects are equipped with a small, inexpensive tag. The tag contains a transponder with a digital memory chip that is given a unique electronic product code . The interrogator, an antenna packaged with a transceiver and decoder, emits a signal activating the RFID tag so it can read and write data to it. When an RFID tag passes through the electromagnetic zone, it detects the reader’s activation signal. The reader decodes the data encoded in the tag’s microchips and the data is passed to the host computer. The application software on the host processes the data, often employing Physical Markup Language (PML).

What is Radio Frequency Identification?

Radio frequency identification, or RFID for short, is a term describing technologies that use radio frequencies to identify objects.

Is RFID technology better than using barcode technology?

Radio frequency identification technology is not necessarily better than bar codes.  It can work in conjunction with bar codes to help manage inventory.  The main difference is the fact that bar codes have to be in the line of site for the scanner to read it, whereas RFID tags can be read in multiple quantities as long as they’re in close proximity of the reader (usually 2-5 ft).  Another benefit of using RFID technology is where barcodes can only identify a type of good; Radio Frequency Identification technology can narrow the information down to the single product itself.  RFID technology furthermore allows for data to be encoded onto the tag allowing multiple reads to occur at the same time.  For example, in one application inventories could be counted in seconds rather than hours, thus utilizing employees at hand more efficiently and productively.

Will RFID technology replace barcodes?

That is not very likely since bar codes are inexpensive and are effective for certain tasks.  RFID will grow and work with the information on the bar code to help inventory management and tracking costs low.

Is RFID technology new?

RFID has been around since the 1970’s, but has been too expensive to operate.  Today, companies are finding cheaper ways to produce the RFID tags now making the whole RFID system more affordable than ever.

Why is RFID technology only starting to catch on now in the supply chain industry?

The main problem has been the standards for RFID.  Most companies request frequency ranges to be Ultra High Frequency (UHF), which offers a longer read range.  UHF is a relatively new technology, and has only started to become affordable recently.  Also, a conversion to RFID is a major step that just one company in the supply chain might not want to do until other companies in the supply chain are ready for RFID.

Are there companies out there today using RFID technology?

Yes, there are many companies around the world using this new technology.  Companies such as Wal-Mart have started the trend by requiring all suppliers to use RFID technology.


What are some of the common applications for RFID?

RFID can be used to track inventory in retail businesses from cereal to toothpaste, can even be used to locate parts needed for equipment repair, as well as collect payments at tolls.  RFID is also being used today at local hospitals in multiple applications.  These are just a few applications; the use of RFID is limitless in its possibilities.

How will RFID benefit my company?

RFID can be used to track work in progress and can speed up the flow of goods in a warehouse.  The main objective of RFID technology is to reduce the cost of labor used in tracking goods, reduce errors in shipping and overall inventory levels, and to increase the overall efficiency in any field.

How does a RFID system work?

The basic parts of an RFID system include an RFID tag that consists of a microchip with a small antenna.  That antenna enables the microchip to receive and respond to Radio-Frequency (RF) queries from an RFID reader or interrogator.  The reader sends out waves to the Tag, after that the Tag responds back to the reader with the information given.  These again are just the basics of an RFID system.

What is the difference between Low-, High-, and Ultra-High Frequencies?

RFID Tags and Readers need to be on the same frequency in order to function.  The differences of the frequencies are similar to those in radio.  Different channels have different information.  Finding the right frequency is critical because radio waves can only function at their own frequency level.

How do I know which frequency to use?

Low end frequencies (LF) require less energy and are less costly.  They work well exceptionally well on non-metallic items.  They do work well around items with high water content, but the read range is limited to just a few feet.  An ultra-high frequency (UHF) is effective at reading tags at further locations.  Also, UHF can transfer the data faster than low end frequencies.  The downfall of UHF is the fact that it cannot read through certain materials, in that case the product would have to be directed at the reader.

Are all countries going to use the same frequency?

The answer is no.  Governments will decide what frequencies to use; they will also regulate the power of the readers to limit the interference with other devices.

What are some common types of RFID equipment being used today?

RFID equipment can be broken into 3 main categories: there are RFID readers, RFID tags, and RFID antennas which are the essentials of RFID equipment and are vital in running an RFID supply chain.  There are other RFID products being used that can add more efficiency to the supply chain, such as RFID printers and RFID smart labels.

Why RFID technology is so important in today’s industry?

Many top end retailers and companies are using RFID technology in today’s market and are requiring suppliers to do the same.  This technology helps any supply chain or business flow much more efficiently with less time spent on tracking.

Why should I use RFID technology?

With growing inventory costs and the down time of lost products, RFID technology can help decrease the extra costs caused by leaks in the supply chain.  RFID technology has been around for many years now, and the use of this technology in supply chains around the world has shown tremendous success in the efficiency and overall flow of the business.

How much information can a tag store?

That depends on the vendor and the application of the tag.  Most tags will use a 96-bit serial number.  These are the simple tags that will be used in most throw away packaging.  The tags can hold up to 2KB of data, however these are not to be just used once and thrown away.

What’s the difference of between read-only and read-write RFID tags?

The Read-Only tags have all the original information the manufacturer placed on them, but have no capability of adding additional information to them.  While Read-Write tags have the ability to add additional information to the tag, it also has the capability to erase and re-write information on a particular tag and can be used again in another product.

What is a WORM tag?

WORM stands for write once, read many.  This acts as a read-only tag where they have no ability to have information added to them; however Worm Tag information is added by the consumer rather the manufacturer.

What are the differences between Active and Passive RFID tags?

Active tags have a power source linked to them similar to a battery; the power is used to broadcast a signal to the reader.  Passive tags draw their power from the reader using electromagnetic waves to induce the antenna on the tag to send out the information.  The key difference between the two is Active tags can be read at longer distances than Passive tags, which subsequently leads to a higher cost.

What is the read range for a typical RFID tag?

There is no simple answer for this question.  Low frequency tags have a range of about 1-2 ft.  Ultra High Frequency (UHF) tags have a range of 20-30ft, and active tags can boost the signal to 300 ft.

What is tag collision?

This is when many tags or transponders send a signal back at the same time, the reader then becomes confused.  Different vendors have come up with different ways to help singulate the tags.

What is energy harvesting?

Most passive RFID tags just reflect back the waves with the information on it.  Energy harvesting is when the tag gathers the energy and stores it for a brief moment, the information is then sent back to the reader at a different frequency.  This method will help the passive tags performance dramatically.

What is a chipless RFID tag?

Chipless tags are a generic term used to describe a tag without a microchip inside.  Instead of a microchip, the radio frequencies take a “picture” of the tag to identify the product; a computer then takes the wave or “picture” and uses it like a fingerprint to identify the product.

RFID doesn't’t work well on metal or water products right?

Well yes and no.  Certain frequencies have a hard time with metal and water.  Low end and high end frequencies have been working well around metal and water.  Some low end frequencies have actually been embedded into some metal car parts without any RFID problems.

What are agile readers?

Agile readers can multitask by being able to read different frequencies or by some other method of communication between the tag and the reader.

What is reader collision?

One small problem with RFID is there can be interference between two readers.  This is called reader collision.  The RFID fields of the readers collide and can cause friction in the supply chain.  One solution might be to have the readers operate at different times to reduce collision.

What is dense reader mode?

Dense reader mode is used when many readers are being used in close proximity.  Each Reader will use a different channel from the other Reader in the vicinity to communicate with the tags.  This prevents reader collision.

Can class 1 and class 0 Readers be upgraded to read EPC gen 2 Tags?

In most cases RFID Readers can be upgraded, it depends on the model or brand.

What is the difference between intelligent and dumb Readers?

Intelligent readers can have many different protocol functions such as storing tag data and can run applications.  Dumb readers might only be able to read one type of tag, one frequency, and the ability to operate one protocol.

Will governments be able to track people with RFID?

Only if they are willing to place RFID tags in every piece of our clothing or put a tag in our skin.  Then the government would have to understand all the information in the database, in other words not likely.

Why do companies want to use RFID if not keep track of the consumers?

RFID will help improve the supply chain to its maximum efficiency.  This means less money spent on tracking, and more money in profits.

What kind of data does a company want to collect?

The RFID is used to help keep items on the shelves for consumers to buy.  RFID wants every product to be accounted for so it can continue to improve the supply chain.

Can RFID tags in consumer products be deactivated?

Yes, there is a kill command that can be used when the item has been purchased.  EPC standards are pushing to have a kill command placed in all Tags so they can never be reactivated.

What is a UPC?

UPC stands for Universal Product Code, which has been used to auto-identify items via machine-readable barcodes for a number of years.

What is an EPC?

The EPC, or Electronic Product Code, is the next generation of automatic product identification. EPCglobal, an organization leading the development of industry standards for EPC, refers to the EPC as a “simple, compact ‘license plate’ that uniquely identifies objects (items, cases, pallets, locations and so on) in the supply chain.”

What are the differences between UPC and EPC?

A UPC only identifies object classes or generic categories of product — such as a pack of Wrigley’s Spearmint gum. An EPC uses a unique serial number to identify each individual pack of gum and makes it possible to automatically track products from manufacturer to store shelf.

What is the difference between an inlay and a label?

An inlay is the functional portion of the RFID label. It is made up of the antenna to which a chip (the brains of the inlay) is attached. The inlay is typically supplied on a substrate or carrier and is called a dry inlay, or if adhesive is added, it is called a wet inlay. In both cases the inlay is supplied to a converter where it is inserted into a label or tag or whatever type of construction is required for the application.

What benefits does RFID have over barcodes?

The most obvious benefit is that RFID does not have to be seen to be read. Bar codes must be placed on the outside of the product and the product must be orientated so the bar code is inline with the scanner. On the other hand, with RFID, you could have (multiple) products inside a sealed carton (for example) and each product can still be identified. Another important difference is that RFID is a read/write technology. So if desired the data can be written (or programmed) after it has been attached to the product. This offers a higher level of flexibility to track and update the data as the product goes through the supply chain, into the end use application or beyond.

What are the components of an RFID tag?

An RFID tag has a protective/printable face-stock then a layer of adhesive.then the RFID inlay.then another layer of adhesive.and finally a removable liner.
The RF inlay provides the RFID functionality. The inlay consists of a carrier sheet that holds an RF antenna, to which is bonded a tiny microchip. The liner and face stock are typically made of paper, but may also be made from other materials such as plastic films.
The selection of materials determines how well the tag will survive and whether it will be compatible with printers, applicators and other system hardware. Material selection may also have to accommodate FDA regulations. In addition, there are mechanical considerations, such as selecting an adhesive that will ensure the tag will remain adhered to the carton.

What is the difference between an inlay and a label?

An inlay is the functional portion of the RFID label. It is made up of the antenna to which a chip (the brains of the inlay) is attached. The inlay is typically supplied on a substrate or carrier and is called a dry inlay, or if adhesive is added, it is called a wet inlay. In both cases the inlay is supplied to a converter where it is inserted into a label or tag or whatever type of construction is required for the application.

What does an RFID inlay consist of?

Functionally, an inlay consists of an antenna and a microchip.
The antenna drives tag performance and governs how well the tag will work in a particular application. Precision-designed to receive and broadcast RF signals, the antenna is made from a conductive material (such as silver, copper or aluminum). The antenna makes contact with an RF reader over a distance determined in large part by the amount of metal and size of the antenna. Contacts attached to the microchip make the circuit between the microchip and antenna.
The chip design determines the protocol or class of the tag’s operation. Different microchips have different features that can also affect performance. RFID microchips contain circuitry capable of handling a variety of functions from power conversion to data storage and retrieval.

What does an RFID strap consist of?

A strap consists of a microchip with two over-sized contact pads on a carrier sheet to facilitate high-speed roll-to-roll manufacturing. In conventional flip-chip manufacturing, the microchip is a very small component.less than 1mm square.with tiny contact pads that must be placed very precisely on the antenna. This is a relatively slow process. To overcome this problem, Avery Dennison RFID Division has developed an innovative high-speed strap attach process that substantially improves yield rates.

What are RFID inlay antennas made of?

Traditionally, RFID antennas were etched from copper — a relatively slow, relatively wasteful process. Today’s antennas tend to be produced with more efficient methods such as etching or stamping.

Why are quality and testing important?

RFID testing provides necessary data on both component quality and expected performance in real-world conditions. Avery Dennison RFID employs an “end-to-end” testing approach, challenging the quality of our inlays from prototype to delivery. Our Atlanta Technical Center simulates the real-world of the supply chain with conveyor, portal and RFID printer and printer/applicator hardware.

What is component testing?

Component testing assures that the inlay’s electronic portions will perform as expected. Different test protocols must be followed for different classes of microchips to evaluate near-field performance. This testing protocol includes a “writing to chip” test performed on Class 0+ and Class 1 inlays (including Gen 2).
Another component of the testing protocol is the read sensitivity test. This is performed on all inlays to make sure they meet far-field requirements.

What is "free space" testing?

Tests performed in free space (i.e. performance tests of unattached tags conducted in a controlled environment) are the starting point for performance tests. Although these tests provide good baseline information, they provide insufficient information on which to select tags for specific applications. Carton contents.the orientation of the tag toward the reader antenna. and other environmental issues such as radio frequency noise and physical object interference can impact performance.

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