RFID is another promising technique, and has been developed since the 1960s. In recent years the cost has dropped to a level allowing it not just to be used in new kind of applications, but also outperforming existing systems. As the name indicates RFID is used to identify objects using radio communication. The most common usage is to identify objects in for example a supermarket. Still, bar code systems outperforms RFID in this area because the cost of a bar code sys- tem is lower than that of an RFID system. The usage of RFID today is for example in road tolls for vehicle access, personnel access control and other security systems. These systems uses more of the potential that RFID offers in form of no line-of-sight required and operating distances of up to tens of meters depending on system used. This is pretty much where the market is today but RFID is continuously breaking into new markets as the systems get cheaper and cheaper when volumes rise. Di®erent applications have di®erent demands on range, power consumption and so on. Therefore different types of RFID systems exist, where the frequency used, modulation scheme and other parameters between them. The main concept used in RFID is however similar for all systems. Each system consists of a reader, an antenna and a population of one or more tags. A tag is like a small memory module which can communicate with the reader and can be attached to objects one wants to track. The reader can search for a tag that is within range by sending out a signal using RF. A tag that receives this signal responds back with its unique ID that has been preprogrammed in its memory. All RFID systems has this basic functionality, but most of the systems today also support multiple tag detection and the ability to write optional information to the tag memory. The most commonly used carrier frequencies are 125 kHz, 13.56 MHz, 868 MHz and 2.4 GHz. Depending on which carrier frequency that is used, di®erent meth- ods for communicating between reader and tag exist. 125 kHz and 13.56 MHz uses inductive coupling to communicate whereas 868 MHz and 2.4 GHz uses electro- magnetic coupling. The electromagnetic coupling is more effcient than inductive coupling implying that systems using electromagnetic coupling often have better reading range. The ability to propagate through solid material is depending on the carrier frequency, lower frequencies give better propagation than higher frequencies. The tags can be either passive or active, meaning that active tags are powered with a power source of their own, while passive tags are powered by the energy radiated by the reader. An active tag has the advantage of longer reading distance at the cost of that battery replacement is needed after some time of operation. Passive tags is the opposite, they don’t need replacement of batteries but instead have shorter reading range. The advantage of not having to replace batteries is preferable in many applications. The source of energy to power the passive tags is the magnetic or electromagnetic field that the reader emits. In the case of inductive coupling the reader uses an antenna to radiate an alternating magnetic field at a constant frequency. A coil in the tag induces voltage, which is used to power the electronics in the tag. By loading its coil the tag it is able to modulate the power drawn from the magnetic field. The reader can sense this and thereby demodulate the information the tag sent. By using a protocol the reader and tag can communicate
RFID World ; Conferences, exhibitions, demonstrations
Nice tutorial on RFID : How RFID Works
Online forum dedicated to RFID RFIDtalk.com
RFID articles 2
RFID news and information
RFID weblog RFID articles
RFID white papers
free download documents on RFID, see power point presentation
RFID Centre Good informational on RFIDRFID papers free download
download RFID EXPLAINED, A BASIC OVERVIEW, by Baird U.S. Equity Research, 2004 FEBRUARY.
download RFID Analog Front End Design Tutorial (version 0.0), Zheng ZhuAuto-ID lab, University of Adelaide
download Low-Cost Electromagnetic Tagging: Design and Implementation, Richard Ribon Fletcher PhD thesis,
download ID Modulation: Embedding Sensor Data in an RFID Timeseries, Joshua R. Smith e.a. 7th Information Hiding Workshop,
download An Ultra-Small Double-Surface Electrode RFID Chip, Mitsuo, Special Section on Papers Selected from AP-ASIC
download Designing the Virtual Battery Agilent
download Designing Detectors for RF/ID Tags, Agilent Application Note
download Schottky Diode Voltage Doubler, Application Note
download Fundamental Operating Principles, Klaus FinkenzellerChapter 3, RFID-Handbook, 2nd edition, http://www.rfid-handbook.de/downloads/E2E_chapter03-rfid-handbook.pdf
download Wireless, remotely powered telemetry in 0.25um CMOS, Fatih Kocer, Paul M. Walsh, and Michael P. Flynn, Wireless Integrated Microsystems Engineering Research Center (WIMS-ERC), University of Michigan,
download WIRELESS BATTERY CHARGING SYSTEM USING RADIO FREQUENCY ENERGY HARVESTING, Daniel W. Harrist MSc. Thesis,
download HF Antenna Design Notes Technical Application Report, Allan Goulbourne , Texas Instruments, 11-08-26-003 Sept 2003, Radio Frequency Identification Systemsystems.
RFID EXPLAINED, A BASIC OVERVIEW, by Baird U.S. Equity Research, 2004 FEBRUARY.
RFID Analog Front End Design Tutorial (version 0.0), Zheng ZhuAuto-ID lab, University of Adelaide.
Low-Cost Electromagnetic Tagging: Design and Implementation, Richard Ribon Fletcher PhD thesis, MIT 2002.
ID Modulation: Embedding Sensor Data in an RFID Timeseries, Joshua R. Smith e.a. 7th Information Hiding Workshop, Barcalona 2005.
An Ultra-Small Double-Surface Electrode RFID Chip, Mitsuo, Special Section on Papers Selected from AP-ASIC 2004 Papers.
Designing the Virtual Battery, Agilent Application Note 1088.
Designing Detectors for RF/ID Tags, Agilent Application Note 1089.
Schottky Diode Voltage Doubler
Wireless, remotely powered telemetry in 0.25um CMOS, Fatih Kocer, Paul M. Walsh, and Michael P. Flynn, Wireless Integrated Microsystems Engineering Research Center (WIMS-ERC), University of Michigan, Ann Arbor, MI 48109.
WIRELESS BATTERY CHARGING SYSTEM USING RADIO FREQUENCY ENERGY HARVESTING, Daniel W. Harrist MSc. Thesis, University of Pittsburgh, 2001.
HF Antenna Design Notes Technical Application Report, Allan Goulbourne, Texas Instruments, 11-08-26-003 Sept 2003, Radio Frequency Identification Systemsystems. An RFID (Radio-Frequency IDentification) tag consists of a small silicon microchip attached to an antenna. The chip itself can be as small as half a millimeter square – roughly the size of a tiny seed. Some RFID tags are thin enough to be embedded in paper. An RFID tag is capable of transmitting a unique serial number a distance of up several meters in response to a query from a reading device. Inexpensive RFID tags are passive, meaning that they lack batteries and obtain their power from the query signal of a reading device itself.RFID tags are already quite common in everyday life. Examples include proximity cards used as replacements for metal door keys, Speedpass™, E-Z Pass™ and FasTrak™ automated toll payment devices. Tens of millions of pets around the world have surgically embedded RFID tags that make it easy to identify them should they lose their collars.
Dropping cost is bringing RFID to the fore. In the near future, some RFID tags may cost as little as $0.05-0.10 in large quantities. We are rapidly approaching a critical turning point at which inexpensive RFID tags are viable as a cost-saving replacement for barcodes, of which some 5 billion are scanned around the world every day. EPCGlobal Inc. is perhaps the most important organization leading the standardization of RFID. Not surprisingly, it is a joint venture of the UCC and EAN, the entities that oversee barcode use in the U.S. and Europe.
RFID tags have two distinct advantages over traditional, printed barcodes:
**An RFID tag carries a unique identifier, whereas a barcode merely indicates an object type. For example, a barcode printed on a box might state that the box contains breakfast cereal, and also indicate the manufacturer. An RFID tag would effectively carry a serial number distinguishing that box of cereal from every other one in the world. This permits very fine-grained and accurate control over product distribution. With a full history for every item, businesses can streamline their manufacturing and distribution processes in unprecedented ways.
An RFID tag may be read by radio contact, without the need for line-of-sight contact. In many cases, it can even be read through objects. A barcode scanner must make close-range optical contact to read a barcode effectively. In contrast, an RFID tag may be read without any real constraint on physical orientation. While an item in a supermarket must be passed over a scanner with its barcode expressly exposed, an RFID tag may be scanned just by being placed in the vicinity of a reader. Indeed, a reader is typically capable of scanning hundreds of RFID tags simultaneously. Again, this means extra efficiency and perhaps accuracy in the handling of items.
RFID TUTORIAL: A Radio-Oriented Introduction to RFID—Protocols, Tags and Applications, Daniel M. Dobkin, Enigmatics, and Titus Wandinger, WJ Communications, High Frequency Electronics
Part 1: Understanding the EPC Gen 2 Protocol, , journal Mark Roberti. The second-generation UHF Electronic Product Code standard offers significant improvements over Gen 1. In part 1 of this special report, we explain the new features in the air-interface protocol, RFID Journal Special Report, Mar. 28, 2005RFID Products
Alien Technology Readers, tags
Matrics RFID Readers, tags.
Intermec RFID tags, readers, and a developer kits.
Symbol RFID readers.
Zebra Printers capable of encoding RFID chips embedded in smart labels and printing text, graphics, and bar codes on the label in a single process.
Sato Printers capable of encoding RFID labels.
Active Wave RFID tags, readers, programmers, and software.
Psion Teklogix Readers
TEK Industries RFID readers and programmers.
RF Code Tags, readers, software, and evaluation kits.
Excort Memory Systems RFID systems
SkyeTek Readers, writers, smartlabels, and tags.
RFind Real-time locating system
Some more links
RFID Journal If you have a serious interest in RFID, I suggest checking out the RFID Journal. The site has a great FAQ page, RFID glossary, and detailed vendor listing. Some of the content (articles, case studies) requires paid subscription.
Uniform Code Council Establishes and promotes multi-industry standards for product identification and related electronic communication. Info on bar code symbologies, compliance labeling, EPC, XML.
News and reports of interest to users of RFID
RFID News Solutions
A bi-monthly publication for supply chain professionals in most major industries and vertical markets who are responsible for designing, purchasing and implementing RFID technologies and solutions.
A monthly magazine that gives you late-breaking news and an insiders’ view of the exploding RFID industry. You will also learn how this technology is being implemented worldwide.
RFID Tag information
RFID Times Blog
A radio frequency ID blog with original content and links to over 400 articles spanning every RFID topic in the world, including RFID tags, readers, integration, middleware, and more.
RFID industry daily newsletter.
RFID White Paper
RFID, Learn about the history and technology behind radio frequency identification in this white paper,
a project of CASPIAN,
Surpriv: RFID Surveillance and Privacy
Investigation of radio-frequency identification, surveillance and privacy issues.
RFID Journal is the only independent media company devoted solely to radio frequency identification and its many business applications. Our mission: to help companies use RFID technology to improve the way they do business.
Association for Automatic Identity and Mobility (AIM)
global trade association comprising providers of components, networks, systems
Information Security: Radio Frequency Identification Technology in the Federal Government
Integrating the Supply Chain with RFID: A Technical and Business Analysis
This paper presents an in-depth analysis of the technical and business implications of adopting Radio Frequency Identification (RFID) in organizational settings.
RFID Definition from Wikipedia
RFID Alien Reader
RFID Blog RFIDbuzz.com
Global source for objective advice on RFID Technology, covering passive and active tags and readers, Savant and application software, and provides free advice, information on implementation issues and solutions.
RFID news weblog RFID Gazette