This application relates to switching Radio Frequency Identification (RFID) tags.
RFID tags are used in a multitude of situations and may need to operate in two or more distinct conditions or states. A basic example of when an RFID tag is configured to alternate between two different states is when an RFID tag can be activated and deactivated. RFID tags may be deactivated by disrupting the radio frequency (RF) field of the tag. The utility of RFID tags, however, depends on their size, simplicity, and efficiency, and methods for deactivating RFID tags should take into account these factors. Further, as RFID tags transition between states, the present state of the RFID tag may be difficult to ascertain. It may be especially challenging to conveniently and accurately determine the current state of RFID tags that are configured to operate in more than two different states.
The present disclosure is directed switching RFID tags. In some implementations, the RFID system includes an RFID tag and a panel. The panel includes one or more contacts configured to move between a first position and a second position. The second position forms an electrical connection between the RFID tag and the one or more contacts to update a state of the RFID tag.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
Like reference symbols in the various drawings indicate like elements.
At a high level, the system 100 can, in some implementations, include one or more RFID tags 120a-c and readers 140a-b. If multiple RFID tags 120 are used, the RFID tags 120 may be used in isolation or grouped together with other RFID tags 120a-c. Each RFID tag 120 may wirelessly communicate one or more RFID readers 140 through an antenna 126. In certain implementations, each RFID tag 120 can include one or more moveable elements, such as a panel 122, that includes one or more conductive pads 124. The panel 122 may be manufactured separately from and later attached or otherwise affixed to the RFID tag 120. The conductive pads 124 may be mounted or otherwise arranged on the panel 122 to align with one or more elements of the RFID tag 120 in one of a plurality of selectable positions associated with the panel 122. In response to a selectable position of the panel 122, the conductive pads 124 for each RFID tag 120 may form a direct or indirect electrical connection to the RFID tag 120 that updates the tag state, such as deactivation or an update to the logic state. The elements of the panel 122 and/or the RFID tag 120 may visually identify a tag state based on, for example, the position of the panel and/or markings of the panel 122 and/or the RFID tag 120. In some examples, a panel 122 in a first position that does not form a connection with the conductive pad 124 with the RFID tag 120 may visually indicate an activated state, whereas a panel 122 in a second position that forms an electrical connection between the conductive pad 124 the RFID tag 120 may visually indicate a deactivated state. Panel 122 may move between the first and second position by way of a variety of methods such as, for example, rotating about a hinge, sliding between positions, folding the panel 122, and/or other methods.
The RFID tags 120 can include any software, hardware, and/or firmware configured to respond to communication from the RFID reader 140. These tags 120 may operate without the use of an internal power supply. Rather, the tags 120 may transmit a reply to a received signal using power stored from the previously received RF signals, independent of an internal power source. This mode of operation is typically referred to as backscattering. In some implementations, the tags 120 alternate between absorbing power from signals transmitted by the RFID reader 140 and transmitting responses to the signals using at least a portion of the absorbed power. In passive tag operation, the tags 120 typically have a maximum allowable time to maintain at least a minimum DC voltage level. In some implementations, this time duration is determined by the amount of power available from an antenna of a tag 120 minus the power consumed by the tag 120 and the size of the on-chip capacitance. The effective capacitance can, in some implementations, be configured to store sufficient power to support the internal DC voltage when there is no received RF power available via the antenna. The tag 120 may consume the stored power when information is either transmitted to the tag 120 or the tag 120 responds to the RFID reader 140 (e.g., modulated signal on the antenna input). In transmitting responses back to the RFID reader 140, the tags 120 may include one or more of the following: an identification string, locally stored data, tag state, internal temperature, and/or others. For example, the tag 120 may transmit information including or otherwise identifying vehicle information such as type, weight, vehicle height, tag height, account number, owner information (e.g., name, license number), and/or other information. In some implementations, the signals can be based, at least in part, on sinusoids having frequencies in the range of 902-928 MHz or 2400-2483.5 MHz. In some implementations, an RFID tag 120 in the inhibited zone may be of a type manufactured to support the ISO 18000-6C standard. An RFID tag manufactured to ISO 18000-6C standard may support dual states: an A state, in which the RFID tag is responsive to RF interrogation, and a B state, in which the RFID tag is temporarily unresponsive to RF interrogation. Under the ISO 18000-6C standard, an RFID tag may typically remain in an unresponsive B state for between 0.8 seconds and 2.0 seconds even without any further power being supplied to the RFID tag 120.
In the illustrated implementations, the RFID tag 120 includes a panel 122, electrical contacts 124, and the antenna 126. The panel 122 may include one or more moveable elements that switch between a plurality of selectable positions. In some implementations, the panel 122 may slide between different positions associated with different tag states. In some implementations, the panel 122 may fold between two positions associated with different states. In some implementations, the panel 122 may present one or more visual indicators identifying a current state of the RFID tag. In a first configuration, the panel 122 may present a green color indicating an active state to observers, and in a second configuration, the panel 122 may present a red color indicating a deactivated state to observers. In response to switching between different configurations, the electrical contacts 124 may dynamically update a state of the RFID tag 120. The electrical contacts 124 may form a shield that substantially prevents the RFID tag 120 from receiving RF signals and/or may form direct or indirect electrical connections with the RFID tag 120 to update the state. In some implementations, the electrical contacts 124 may shield, using conductive elements, the RFID tag 120 to substantially prevent reception of RF signals. For example, the electrical contacts 124 may include a metal foil that overlays at least a portion of the RFID 120 in a first position such that the metal foil substantially shields the antenna 126. In some implementations, the electrical contacts 124 may deactivate the tag 120 by shorting the antenna. For example, the electrical contacts 124 may include a conductive bar that directly or indirectly contacts the antenna 126 to form a short.
The RFID reader 140 can include any software, hardware, and/or firmware configured to transmit and receive RF signals. In general, the RFID reader 140 may transmit a request for information within a certain geographic area, or interrogation zone, associated with the reader 140. The reader 140 may transmit the query in response to a request, automatically, in response to a threshold being satisfied (e.g., expiration of time), as well as other events. The interrogation zone may be based on one or more parameters such as transmission power, associated protocol, nearby impediments (e.g., objects, walls, buildings), as well as others. In general, the RFID reader 140 may include a controller, a transceiver coupled to the controller (not illustrated), and at least one RF antenna 142 coupled to the transceiver. In the illustrated example, the RF antenna 142 transmits commands generated by the controller through the transceiver and receives responses from RFID tags 120 and/or antennas 126 in the associated interrogation zone. In certain cases such as tag-talks-first (TTF) systems, the reader 140 may not transmit commands but only RF energy. In some implementations, the controller can determine statistical data based, at least in part, on tag responses. The readers 140 often include a power supply or may obtain power from a coupled source for powering included elements and transmitting signals. In some implementations, the reader 140 operates in one or more of frequency bands allotted for RF communication. For example, the Federal Communication Commission (FCC) has assigned 902-928 MHz and 2400-2483.5 MHz as frequency bands for certain RFID applications. In some implementations, the reader 140 may dynamically switch between different frequency bands. For example, the reader 140 may switch between European bands 860 to 870 MHz and Japanese frequency bands 952 MHz to 956 MHz. Some implementations of system 100 may further include an RFID reader 140 to control timing, coordination, synchronization, and/or signal strength of transmissions by inhibitor antenna and RFID antenna.
In general, RFID tags 120 may switch between activated and deactivated states. In some implementations, deactivation of an RFID tag 120 ordinarily involves suppressing the RF field of the RFID tag. The suppression of the RF field can be accomplished by physically blocking the RF carrier or electrically deactivating the RFID tag's antenna.
Some applications may include more functionality than merely the ability to read or deactivate an RFID tag. For example, some applications may update the tag's response as compared with deactivation. Accordingly, in certain implementations, an RFID tag, such as multi-level switched state RFID tags, can switch to different states in addition to an activated and deactivated state and can be switched between the plurality of states in response to a moveable element. In these instances, the RFID tag may be set to a logical state by altering the RF energy instead of shorting the RF energy, as may be implemented when deactivating the RFID tag.
A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.
Number | Name | Date | Kind |
---|---|---|---|
3568197 | Cubley | Mar 1971 | A |
3663932 | Mount et al. | May 1972 | A |
3688250 | Howlett | Aug 1972 | A |
3693059 | Harris | Sep 1972 | A |
3696429 | Tressa | Oct 1972 | A |
3876946 | La Clair et al. | Apr 1975 | A |
3984835 | Kaplan et al. | Oct 1976 | A |
4243955 | Daniel et al. | Jan 1981 | A |
4297672 | Fruchey et al. | Oct 1981 | A |
4325057 | Bishop | Apr 1982 | A |
4509123 | Vereen | Apr 1985 | A |
4595915 | Close | Jun 1986 | A |
4849706 | Davis et al. | Jul 1989 | A |
4857925 | Brubaker | Aug 1989 | A |
4870391 | Cooper | Sep 1989 | A |
4873529 | Gibson | Oct 1989 | A |
4903033 | Tsao et al. | Feb 1990 | A |
4968967 | Stove | Nov 1990 | A |
5012225 | Gill | Apr 1991 | A |
5021780 | Fabiano et al. | Jun 1991 | A |
5038283 | Caveney | Aug 1991 | A |
5095536 | Loper | Mar 1992 | A |
5165109 | Han et al. | Nov 1992 | A |
5278563 | Spiess | Jan 1994 | A |
5278569 | Ohta et al. | Jan 1994 | A |
5293408 | Takahashi et al. | Mar 1994 | A |
5334822 | Sanford | Aug 1994 | A |
5381157 | Shiga | Jan 1995 | A |
5396489 | Harrison | Mar 1995 | A |
5430441 | Bickley et al. | Jul 1995 | A |
5444864 | Smith | Aug 1995 | A |
5461374 | Lewiner et al. | Oct 1995 | A |
5477215 | Mandelbaum | Dec 1995 | A |
5495500 | Jovanovich et al. | Feb 1996 | A |
5506584 | Boles | Apr 1996 | A |
5519729 | Jurisch et al. | May 1996 | A |
5539394 | Cato et al. | Jul 1996 | A |
5608379 | Narlow et al. | Mar 1997 | A |
5613216 | Galler | Mar 1997 | A |
5630072 | Dobbins | May 1997 | A |
5648767 | O'Connor et al. | Jul 1997 | A |
5649295 | Shober et al. | Jul 1997 | A |
5661485 | Manuel | Aug 1997 | A |
5661494 | Bondyopadhyay | Aug 1997 | A |
5668558 | Hong | Sep 1997 | A |
5708423 | Ghaffari et al. | Jan 1998 | A |
5729576 | Stone et al. | Mar 1998 | A |
5745037 | Guthrie et al. | Apr 1998 | A |
5777561 | Chieu et al. | Jul 1998 | A |
5784414 | Bruekers et al. | Jul 1998 | A |
5825753 | Betts et al. | Oct 1998 | A |
5831578 | Lefevre | Nov 1998 | A |
5841814 | Cupo | Nov 1998 | A |
5850187 | Carrender et al. | Dec 1998 | A |
5861848 | Iwasaki | Jan 1999 | A |
5892396 | Anderson et al. | Apr 1999 | A |
5898405 | Iwasaki | Apr 1999 | A |
5905405 | Ishizawa | May 1999 | A |
5940006 | MacLellan et al. | Aug 1999 | A |
5974301 | Palmer et al. | Oct 1999 | A |
6025780 | Bowers et al. | Feb 2000 | A |
6026378 | Onozaki | Feb 2000 | A |
6084530 | Pidwerbetsky et al. | Jul 2000 | A |
6094149 | Wilson | Jul 2000 | A |
6107910 | Nysen | Aug 2000 | A |
6121929 | Olson et al. | Sep 2000 | A |
6137447 | Saitoh et al. | Oct 2000 | A |
6177861 | MacLellan et al. | Jan 2001 | B1 |
6192225 | Arpaia et al. | Feb 2001 | B1 |
6219534 | Torii | Apr 2001 | B1 |
6229817 | Fischer et al. | May 2001 | B1 |
6229987 | Greeff et al. | May 2001 | B1 |
6232837 | Yoo et al. | May 2001 | B1 |
6275192 | Kim | Aug 2001 | B1 |
6286762 | Reynolds et al. | Sep 2001 | B1 |
6317027 | Watkins | Nov 2001 | B1 |
6320542 | Yamamoto et al. | Nov 2001 | B1 |
6366216 | Olesen | Apr 2002 | B1 |
6412086 | Friedman et al. | Jun 2002 | B1 |
6414626 | Greef et al. | Jul 2002 | B1 |
6442276 | Doljack | Aug 2002 | B1 |
6456668 | MacLellan et al. | Sep 2002 | B1 |
6459687 | Bourlas et al. | Oct 2002 | B1 |
6466130 | Van Horn et al. | Oct 2002 | B2 |
6492933 | McEwan | Dec 2002 | B1 |
6501807 | Chieu et al. | Dec 2002 | B1 |
6531957 | Nysen | Mar 2003 | B1 |
6538564 | Cole | Mar 2003 | B1 |
6566997 | Bradin | May 2003 | B1 |
6567648 | Ahn et al. | May 2003 | B1 |
6603391 | Greeff et al. | Aug 2003 | B1 |
6639509 | Martinez | Oct 2003 | B1 |
6700547 | Mejia et al. | Mar 2004 | B2 |
6714121 | Moore | Mar 2004 | B1 |
6714133 | Hum et al. | Mar 2004 | B2 |
6768441 | Singvall et al. | Jul 2004 | B2 |
6774685 | O'Toole et al. | Aug 2004 | B2 |
6784789 | Eroglu et al. | Aug 2004 | B2 |
6794000 | Adams et al. | Sep 2004 | B2 |
6798384 | Aikawa et al. | Sep 2004 | B2 |
6816125 | Kuhns et al. | Nov 2004 | B2 |
6819938 | Sahota | Nov 2004 | B2 |
6831603 | Menache | Dec 2004 | B2 |
6838989 | Mays et al. | Jan 2005 | B1 |
6888509 | Atherton | May 2005 | B2 |
6974928 | Bloom | Dec 2005 | B2 |
7009496 | Arneson et al. | Mar 2006 | B2 |
7034689 | Teplitxky et al. | Apr 2006 | B2 |
7039359 | Martinez | May 2006 | B2 |
7043269 | Ono et al. | May 2006 | B2 |
7053755 | Atkins et al. | May 2006 | B2 |
7058368 | Nicholls et al. | Jun 2006 | B2 |
7083083 | Droz | Aug 2006 | B2 |
7084769 | Bauer et al. | Aug 2006 | B2 |
7088248 | Forster | Aug 2006 | B2 |
7091828 | Greeff et al. | Aug 2006 | B2 |
7095324 | Conwell et al. | Aug 2006 | B2 |
7095985 | Hofmann | Aug 2006 | B1 |
7099406 | Najarian et al. | Aug 2006 | B2 |
7099671 | Liang | Aug 2006 | B2 |
7100835 | Selker | Sep 2006 | B2 |
7109867 | Forster | Sep 2006 | B2 |
7155172 | Scott | Dec 2006 | B2 |
7180402 | Carrender et al. | Feb 2007 | B2 |
7197279 | Bellantoni | Mar 2007 | B2 |
7199713 | Barink et al. | Apr 2007 | B2 |
7213767 | Tethrake et al. | May 2007 | B2 |
7215976 | Brideglall | May 2007 | B2 |
7221900 | Reade et al. | May 2007 | B2 |
7256682 | Sweeney, II | Aug 2007 | B2 |
7257079 | Bachrach | Aug 2007 | B1 |
7284703 | Powell et al. | Oct 2007 | B2 |
7357299 | Frerking | Apr 2008 | B2 |
7375634 | Sprague | May 2008 | B2 |
7385511 | Muchkaev | Jun 2008 | B2 |
7388468 | Diorio et al. | Jun 2008 | B2 |
7388501 | Tang et al. | Jun 2008 | B2 |
7409194 | Shi et al. | Aug 2008 | B2 |
7411505 | Smith et al. | Aug 2008 | B2 |
7413124 | Frank et al. | Aug 2008 | B2 |
7429953 | Buris et al. | Sep 2008 | B2 |
7432817 | Phipps et al. | Oct 2008 | B2 |
7432874 | Meissner | Oct 2008 | B2 |
7440743 | Hara et al. | Oct 2008 | B2 |
7450919 | Chen et al. | Nov 2008 | B1 |
7460014 | Pettus | Dec 2008 | B2 |
7477151 | Forster et al. | Jan 2009 | B2 |
7477887 | Youn | Jan 2009 | B2 |
7479874 | Kim et al. | Jan 2009 | B2 |
7492812 | Ninomiya et al. | Feb 2009 | B2 |
7526266 | Al-Mahdawi | Apr 2009 | B2 |
7548153 | Gravelle et al. | Jun 2009 | B2 |
7551085 | Pempsell et al. | Jun 2009 | B2 |
7557762 | Shimasaki et al. | Jul 2009 | B2 |
7561866 | Oliver et al. | Jul 2009 | B2 |
7562083 | Smith et al. | Jul 2009 | B2 |
7570164 | Chakraborty et al. | Aug 2009 | B2 |
7576657 | Duron et al. | Aug 2009 | B2 |
7580378 | Carrender et al. | Aug 2009 | B2 |
7583179 | Wu et al. | Sep 2009 | B2 |
7586416 | Ariyoshi et al. | Sep 2009 | B2 |
7592898 | Ovard et al. | Sep 2009 | B1 |
7592915 | Liu | Sep 2009 | B2 |
7594153 | Kim et al. | Sep 2009 | B2 |
7595729 | Ku et al. | Sep 2009 | B2 |
7596189 | Yu et al. | Sep 2009 | B2 |
7606532 | Wuidart | Oct 2009 | B2 |
7609163 | Shafer | Oct 2009 | B2 |
7612675 | Miller et al. | Nov 2009 | B2 |
7782206 | Burnett et al. | Aug 2010 | B2 |
7948381 | Lindsay et al. | May 2011 | B2 |
8018344 | Chang et al. | Sep 2011 | B2 |
20010048715 | Lee et al. | Dec 2001 | A1 |
20020021208 | Nicholson et al. | Feb 2002 | A1 |
20020067264 | Soehnlen | Jun 2002 | A1 |
20020072344 | Souissi | Jun 2002 | A1 |
20020119748 | Prax et al. | Aug 2002 | A1 |
20020141347 | Harp et al. | Oct 2002 | A1 |
20030021367 | Smith | Jan 2003 | A1 |
20030052161 | Rakers et al. | Mar 2003 | A1 |
20030107877 | Mennecart | Jun 2003 | A1 |
20030116634 | Tanaka | Jun 2003 | A1 |
20030228860 | Jou | Dec 2003 | A1 |
20050084003 | Duron et al. | Apr 2005 | A1 |
20050099270 | Diorio et al. | May 2005 | A1 |
20050099340 | Suzuki | May 2005 | A1 |
20050107051 | Aparin et al. | May 2005 | A1 |
20050114326 | Smith et al. | May 2005 | A1 |
20050116867 | Park et al. | Jun 2005 | A1 |
20050128085 | Bon | Jun 2005 | A1 |
20050134461 | Gelbman et al. | Jun 2005 | A1 |
20050156031 | Goel et al. | Jul 2005 | A1 |
20050179520 | Ziebertz | Aug 2005 | A1 |
20050237843 | Hyde | Oct 2005 | A1 |
20050259768 | Yang et al. | Nov 2005 | A1 |
20060017570 | Moskowitz et al. | Jan 2006 | A1 |
20060022800 | Krishna et al. | Feb 2006 | A1 |
20060086809 | Shanks et al. | Apr 2006 | A1 |
20060098765 | Thomas et al. | May 2006 | A1 |
20060103533 | Pahlavan et al. | May 2006 | A1 |
20060125603 | Nahear | Jun 2006 | A1 |
20060132313 | Moskowitz | Jun 2006 | A1 |
20060183454 | Al-Mahdawi | Aug 2006 | A1 |
20060214773 | Wagner et al. | Sep 2006 | A1 |
20060238302 | Loving et al. | Oct 2006 | A1 |
20060252398 | Park et al. | Nov 2006 | A1 |
20060267734 | Taki et al. | Nov 2006 | A1 |
20060290502 | Rawlings | Dec 2006 | A1 |
20070001809 | Kodukula et al. | Jan 2007 | A1 |
20070001813 | Maguire et al. | Jan 2007 | A1 |
20070018792 | Take et al. | Jan 2007 | A1 |
20070046432 | Aiouaz et al. | Mar 2007 | A1 |
20070060075 | Mikuteit | Mar 2007 | A1 |
20070082617 | McCallister | Apr 2007 | A1 |
20070109101 | Colby | May 2007 | A1 |
20070133392 | Shin et al. | Jun 2007 | A1 |
20070139200 | Yushkov et al. | Jun 2007 | A1 |
20070152829 | Lindsay et al. | Jul 2007 | A1 |
20070164868 | Deavours et al. | Jul 2007 | A1 |
20070188305 | Drucker | Aug 2007 | A1 |
20070205953 | Bombay et al. | Sep 2007 | A1 |
20070206704 | Zhou et al. | Sep 2007 | A1 |
20070206705 | Stewart | Sep 2007 | A1 |
20070222604 | Phipps et al. | Sep 2007 | A1 |
20070222606 | Phipps et al. | Sep 2007 | A1 |
20070236335 | Aiouaz et al. | Oct 2007 | A1 |
20070285238 | Batra | Dec 2007 | A1 |
20070290846 | Schilling et al. | Dec 2007 | A1 |
20070290858 | Janke et al. | Dec 2007 | A1 |
20080012688 | Ha et al. | Jan 2008 | A1 |
20080018431 | Turner et al. | Jan 2008 | A1 |
20080048867 | Oliver et al. | Feb 2008 | A1 |
20080049870 | Shoarinejad et al. | Feb 2008 | A1 |
20080065957 | Shoarinejad et al. | Mar 2008 | A1 |
20080068173 | Alexis et al. | Mar 2008 | A1 |
20080084310 | Nikitin et al. | Apr 2008 | A1 |
20080136595 | Finkenzeller | Jun 2008 | A1 |
20080143486 | Downie et al. | Jun 2008 | A1 |
20080191961 | Tuttle | Aug 2008 | A1 |
20080258916 | Diorio et al. | Oct 2008 | A1 |
20080278286 | Takaluoma et al. | Nov 2008 | A1 |
20090022067 | Gotwals | Jan 2009 | A1 |
20090053996 | Enguent et al. | Feb 2009 | A1 |
20090091454 | Tuttle | Apr 2009 | A1 |
20090096612 | Seppa et al. | Apr 2009 | A1 |
20090101720 | Dewan et al. | Apr 2009 | A1 |
20100194542 | Noakes et al. | Aug 2010 | A1 |
Number | Date | Country |
---|---|---|
2218269 | Apr 1999 | CA |
102005062827 | Jun 2007 | DE |
0133317 | Feb 1985 | EP |
0498369 | Aug 1992 | EP |
0156440 | Dec 1992 | EP |
0915573 | May 1999 | EP |
0923061 | Jun 1999 | EP |
1095427 | May 2001 | EP |
1436857 | Jul 2004 | EP |
2178023 | Apr 2010 | EP |
2178023 | Apr 2010 | EP |
2648602 | Dec 1990 | FR |
1270456 | Apr 1972 | GB |
1158836 | Jun 1989 | JP |
2002-185381 | Jun 2002 | JP |
2005-227818 | Aug 2005 | JP |
2005-253058 | Sep 2005 | JP |
2006-252367 | Sep 2006 | JP |
2002-0091572 | Dec 2002 | KR |
WO 9016119 | Dec 1990 | WO |
WO 9905659 | Feb 1999 | WO |
WO 0124407 | Apr 2001 | WO |
WO 03044892 | May 2003 | WO |
WO 2004001445 | Dec 2003 | WO |
WO 2005072137 | Aug 2005 | WO |
WO 2006037241 | Apr 2006 | WO |
WO 2006068635 | Jun 2006 | WO |
WO 2007003300 | Jan 2007 | WO |
WO 2007094787 | Aug 2007 | WO |
WO 2007126240 | Nov 2007 | WO |
WO 2009058809 | May 2009 | WO |
Entry |
---|
U.S. Appl. No. 12/856,706, filed Aug. 16, 2010, Burnett. |
International Search Report and Written Opinion issued in international application No. PCT/US2010/036878, mailed Aug. 31, 2010, 15 pages. |
Bridgelall, Raj; “Bluetooth/802.11 Protocol Adaptation for RFID Tags”; Symbol Technologies, Research & Development, One Symbol Plaza, Holtsville, New York 11742; 4 pages. Retrieved from <http://www2.ing.unipi.it/ew2002/proceedings/001.pdf>. |
Burgener, E.C.; “A Personal Transit Arrival Time Receiver;” IEEE—IEE Vehicle Navigation & Information Systems Conference; Ottawa, Ontario, Canada; 1993; pp. 54-55. Retrieved from <http://ieeexplore.ieee.org/xpl/freeabs—all.jsp?arnumber=585583>. |
Cavoukian, Ann; “Adding an On/Off Device to Activate the RFID in Enhanced Driver's Licenses: Pioneering a Made-in-Ontario Transformative Technology that Delivers Both Privacy and Security”; Information and Privacy Commissioner of Ontario; Ontario, Canada; Mar. 2009; 3 pages. Retrieved from <http://www.ipc.on.ca/images/Resources/edl.pdf>. |
Desmons, Dimitri; “UHF Gen 2 for Item-Level Tagging”; Impinji, Inc.; 24 pages. Retrieved from <http://www.impinj.com/files/Impinj—ILT—RFID—World.pdf>, [Feb. 27, 2006]. |
Donovan, John; “Software-Defined Radio Tackles Wireless Compatibility Issues”; Portable Design; Apr. 2006; pp. 8-12. Retrieved from <http://www.qmags.com/download/default.aspx?pub=PD&upid=11675&fl=others/PD/PD—20060401—Apr—2006.pdf>. |
Han Y. et al.; “System Modeling and Simulation of RFID”; Auto-ID Labs at Fudan University, Shanghai, P.R. China; 12 pages. Retrieved from <http://www.citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.116.7275&rep=rep1&type=pdf>,[Mar. 29, 2006]. |
Hansen, T. et al.; “Method for Controlling the Angular Extent of Interrogation Zones in RFID”; Seknion, Inc., 2000 Commonwealth Avenue, Suite 1008, Boston, MA 02135; 12 pages. Retrieved from <http://seknion.com/DOWNLOADS/Seknion—Paper—RFID.pdf>, [Apr. 24, 2006]. |
Hiltunen, Kimmo; “Using RF Repeaters to Improve WCDMA HSDPA Coverage and Capacity inside Buildings”; The 17th Annual IEEE International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC-06); 2006; 5 pages. Retrieved from <http://www.ericsson.com/technology/research—papers/wireless—access/doc/PIMRC06—hiltunen.pdf>. |
Khandelwal, G. et al. “Intelligent MAC Design for RFID Networks”; The Pennsylvania State University; 1 page, [Oct. 5, 2005]. |
Khandelwal, G. et al.; “OPT: Optimal Protocol Tree for Efficient Tag Identification in Dense RFID Systems”; IEEE International Conference on Communications; Jun. 11-15, 2006; pp. 128-133. |
Kusy et al.; “Tracking Mobile Nodes Using RF Doppler Shifts”; Vanderbilt University, Nashville, Tennessee; 14 pages. Retrieved from <http://www.isis.vanderbilt.edu/sites/default/files/Kusy—B—11—7—2007—Tracking—M.pdf>, [Nov. 7, 2007]. |
“New Alien Software Can Identify Velocity, Position of Tags”; RFID News; Apr. 14, 2008; 2 pages. Retrieved from <http://www.rfidnews.org/2008/04/14/new-alien-software-can-identify-velocity-position-of-tags>. |
O'Connor, Mary Catherine; “Wal-Mart Seeks UHF for Item-Level”; RFID Journal, Inc.; 2005; 2 pages. Retrieved from <http://www.rfidjournal.com/article/articleview/2228/1/1/>. |
Rohatgi, A. et al.; “Implementation of an Anti-Collision Differential-Offset Spread Spectrum FRID System”; Georgia Institute of Technology, School of Electrical and Computer Engineering; IEEE Antennas Propagation Society International Symposium 2006; 4 pages. Retrieved from <http://www.propagation.gatech.edu/Archive/PG—CP—060710—AR/PG—CP—060710—AR.PDF>. |
Waldrop et al.; “Colorwave: A MAC for RFID Reader Networks”; Auto-ID Center, Massachusetts Institute of Technology, Cambridge, MA; 4 pages, [May 28, 2003]. |
Yu, P. et al.; “Securing RFID with Ultra-Wideband Modulation”; Virginia Tech Electrical and Computer Engineering Department; Blacksburg, VA; Workshop on RFID Security; Jul. 2006; 12 pages. Retrieved from <http://events.iaik.tugraz.at/RFIDSec06/Program/papers/004%20-%20Ultra%20Wideband%20Modulation.pdf>. |
“Near Field UHF Versus HF”; IDTechEx; May 16, 2006; 1 page. Retrieved from <http://www.idtechex.com/research/articles/near—field—uhf—versus—hf—00000474.asp>. |
Kiming, Q. et al.; “Development of a 3cm Band Reflected Power Canceller”; Research Institute of Navigation Technology; 2001 CIE International Conference on, Proceedings; 2001; pp. 1098-1102. |
“Developments in Printed Conductors and Tags”; IDTechEx; Jun. 6, 2005; 1 page. Retrieved from <http://www.idtechex.com/research/articles/developments—in—printed—conductors—and—tags—00000188.asp>. |
Ryu, H-K. et al.; “Size Reduction in UHF Band RFID Tag Antenna Based on Circular Loop Antenna”; 18th International Conference on Applied Electromagnetics and Communications, ICECom; Oct. 12-14, 2005; pp. 1-4. |
Binu P, et al.; “A New Microstrip Patch Antenna for Mobile Communications and Bluetooth Applications”; Microwave and Optical Technology Letters; vol. 33, No. 4, May 20, 2002; pp. 285-286. |
Garg et al.; “Microstrip Radiators”; Microstrip Antenna Design Handbook; Artech House, Inc. Norwood, MA; 2001; pp. 1-72. |
“Radio Frequency Identification (RFID) Primer” 23 pages. Retrieved from <http://ocw.mit.edu/NR/rdonlyres/Sloan-School-of-Management/15-762JSpring-2005/23F46055-7F21-4046-B2C3-7E96680790DD/0/rfid—primer.pdf>, [Feb. 15, 2005]. |
Communication Pursuant to Article 94(3) EPC issued in European Application No. 10727239.5 on Oct. 17, 2012; 3 pages. |
International Preliminary Report on Patentability issued in International Application No. PCT/US2010/036878 dated Aug. 29, 2011, 9 pages. |
Number | Date | Country | |
---|---|---|---|
20100302012 A1 | Dec 2010 | US |