Editing Radio-frequency identification (section)

==History==
{{See also|History of radar}}
[[Image:FasTrak transponder.jpg|right|frame|[[FasTrak]], an RFID tag used for [[electronic toll collection]] in California]]

In 1945, [[Leon Theremin]] invented [[Thing (listening device)|the "Thing", a listening device]] for the [[Soviet Union]] which retransmitted incident radio waves with the added audio information. Sound waves vibrated a [[diaphragm (acoustics)|diaphragm]] which slightly altered the shape of the [[resonator]], which modulated the reflected radio frequency. Even though this device was a [[covert listening device]], rather than an identification tag, it is considered to be a predecessor of RFID because it was passive, being energised and activated by waves from an outside source.<ref>{{Cite book|title=Hacking Exposed Linux: Linux Security Secrets & Solutions|publisher=McGraw-Hill Osborne Media|edition=third|url=https://books.google.com/books?id=f5Vz08spzw8C|year=2008|page=298|isbn=978-0-07-226257-5}}</ref>

Similar technology, such as the [[Identification friend or foe]] [[transponder]], was routinely used by the Allies and Germany in [[World War II]] to identify aircraft as friendly or hostile. [[Transponder (aviation)|Transponders]] are still used by most powered aircraft.<ref>{{Cite web|title=What are IFF Technologies?|url=https://www.baesystems.com/en-us/definition/what-are-iff-technologies|access-date=2021-03-29|website=BAE Systems - United States|language=en}}</ref> An early work exploring RFID is the landmark 1948 paper by Harry Stockman,<ref>{{citation|first=Harry|last=Stockman|title=Communication by Means of Reflected Power|journal=Proceedings of the IRE|volume=36|issue=10|pages=1196–1204|doi=10.1109/JRPROC.1948.226245|date=October 1948|s2cid=51643576}}</ref> who predicted that "Considerable research and development work has to be done before the remaining basic problems in reflected-power communication are solved, and before the field of useful applications is explored."

[[Mario Cardullo]]'s device, patented on January 23, 1973, was the first true ancestor of modern RFID,<ref name="rfidjournal1">{{cite web|url=http://www.rfidjournal.com/article/view/392/1/2|archive-url=https://web.archive.org/web/20090307013857/http://www.rfidjournal.com/article/view/392/1/2|archive-date=March 7, 2009|title=Genesis of the Versatile RFID Tag|date=10 October 2012|publisher=RFID Journal|access-date=2013-09-22}}</ref> as it was a passive radio transponder with memory.<ref>{{Cite patent|inventor-last=Cardullo|inventor-first=Mario W.|inventor2-last=Parks|inventor2-first=William L.|title=Transponder apparatus and system|country-code=US|patent-number=3713148|publication-date=May 21, 1970|issue-date=Jan 23, 1973}}</ref> The initial device was passive, powered by the interrogating signal, and was demonstrated in 1971 to the [[Port Authority of New York and New Jersey|New York Port Authority]] and other potential users. It consisted of a transponder with 16 [[bit]] memory for use as a [[electronic toll collection|toll device]]. The basic Cardullo patent covers the use of radio frequency (RF), sound and light as transmission carriers. The original business plan presented to investors in 1969 showed uses in transportation (automotive vehicle identification, automatic toll system, [[electronic license plate]], electronic manifest, vehicle routing, vehicle performance monitoring), banking (electronic chequebook, electronic credit card), security (personnel identification, automatic gates, surveillance) and medical (identification, patient history).<ref name="rfidjournal1"/>

In 1973, an early demonstration of ''reflected power'' (modulated backscatter) RFID tags, both passive and semi-passive, was performed by Steven Depp, Alfred Koelle and Robert Freyman at the [[Los Alamos National Laboratory]].<ref name=shrouds>{{cite web|author=Landt, Jerry| year=2001| title=Shrouds of Time: The history of RFID|work=AIM, Inc.| url=http://www.transcore.com/pdf/AIM%20shrouds_of_time.pdf|access-date=2006-05-31|archive-url=https://web.archive.org/web/20090327005501/http://www.transcore.com/pdf/AIM%20shrouds_of_time.pdf|archive-date=2009-03-27}}</ref> The portable system operated at 915&nbsp;MHz and used 12-bit tags. This technique is used by the majority of today's UHFID and microwave RFID tags.<ref>
{{cite web|url=http://www.clarinox.com/docs/whitepapers/RealTime_main.pdf|title= Real Time Location Systems|publisher=clarinox|access-date=2010-08-04}}</ref>

In 1983, the first patent to be associated with the abbreviation RFID was granted to [[Charles Walton (inventor)|Charles Walton]].<ref>Charles A. Walton "Portable radio frequency emitting identifier" {{US Patent|4,384,288}} issue date May 17, 1983</ref>

In 1996, the first patent for a batteryless RFID passive tag with limited interference was granted to David Everett, John Frech, Theodore Wright, and Kelly Rodriguez.<ref>David F. Everett, John W. Frech, Theodore Wright, Kelly M. Rodriguez "Identification system and method with passive tag" {{US Patent|5,491,468}} issue date February 13, 1996</ref>