Indisputable Key - Glossary - RFID Transponder

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Synonyms

RFID Tag

Related expressions

RFID Reader, Transponder applicator, RFID

Explanation

A transponder, or a tag as it also called, is attached to all items to be identified in a RFID system. The transponder contains information, at minimum an ID code, which can be wirelessly read from a distance. The transponder consists of (Figure 10):

an integrated circuit (IC) chip, which contains the electronics and data memory, and
an antenna for transmitting and receiving radio signals.

The antenna and the microchip are usually mounted on a substrate, which provides mechanical support and may form an integral part of the antenna. This assembly is called the inlay of the transponder. The substrate material in the inlay is also called the matrix material. The inlay may be enclosed into a casing for better tolerance for the environment such as rain, snow, dirt and impacts by objects.

Figure 10 : An example of a transponder inlay

The most common UHF antennas used in RFID transponders are dipoles and patch antennas.
A dipole antenna can be a wire antenna similar to the conventional radio antennas found for example in cars. Patch antennas are commonly used as internal antennas in mobile phones. Figure 10, illustrating the transponder inlay shows an example of an RFID transponder with a patch antenna.

Antenna design is a critical part of the transponder design as the antenna is typically the largest component of the transponder and it has a great effect on the performance of transponder, especially the reading distance as a larger antenna allows a longer reading distance.

The microchip (integrated circuit, IC) in the transponder contains the electronics for the transponder. The chip takes its operating power from the radio signal received by the antenna and decodes the received signal, for example a read command from the reader. In the chip, a simple «processor» performs the actions related to the received command and a memory circuit containing the ID code of the transponder and possibly other data. The chip then codes the ID number (and other data) into the signal that is transmitted back to the reader with the antenna. The format and coding of the information that the transponder transmits is specified in RFID standards.

Application/usage in Indisputable KEY

A significant part of Indisputable KEY is the utilization of traceability systems and RFID is one of the most relevant technologies to use. The transponder can be considered as the basis of the forest RFID system as many items to be identified must carry a transponder. Enhancement of the knowledge on RFID transponder design and optimisation for the forest wood chain are among the scientific objectives of the project together with the application of a pulping process compatible renewable artificial wood material for the transponders.

The Electronic Product Code (EPC) Class 1 Generation 2 specifications define the operation of the UHF RFID transponders for the forest RFID system to be implemented in the Indisputable KEY. This standard specifies details of the radio signals to be used and the format of the data to be transferred by the transponder and the reader. The transponder contains an ID code consisting of 96-bits.
Different dipole- and patch-type antenna concepts are investigated in the Indisputable KEY project as the transponders are to be attached or embedded into logs using an automatic applicator, which presents many technical challenges in the design of the transponder structure.

Conventional plastics cause problems in the paper production as plastic residue in the pulp decreases the quality of the paper and plastic droplets may even ruin considerable amounts of paper. In many countries, the wood chips produced in the sawing at the mill are used as raw material in pulp and paper manufacturing. The transponders attached to the logs end up into the pulping process among the wood chips so conventional plastic substrate or matrix materials cannot be used in the transponders. As a solution to this problem, a novel artificial wood material is being developed in the Indisputable KEY project (see “Artificial wood material”)

Institutions with teaching capabilities

RFID Lab is a Finnish application center for RFID technology, especially focusing on logistics systems. RFID Lab Finland offers neutral information, consulting, training and measuring services to the interested parties in Finland.

OTA Training LLC (US) offers RFID training courses worldwide (web based training, in a classroom or in a RFID facility). OTA was chosen as one of the 20 Leading RFID Innovators in 2008.

RFID4U (Canadian) provides RFID training and RFID certification to help companies align technology with business objectives. All courses are taught by senior RFID senior RFID practitioners/trainers with practicality in mind, offering the techniques and tips that ensure rapid RFID evaluation and deployment.

Available text books and training material

Automation.com provides online Web-based training Course about RFID Technology. The course covers six areas: Basic Concepts, RFID Physics, Practical RFID systems, Middleware and standards, RFID applications, Security & Privacy issues. There is also RFID training CD.

”R-LIM: an Affordable Library Search System Based on RFID (proceedings of the 2006 International Conference on Hybrid Information Technology)
For different examples of different RFID tags click here