# US 2008/0185540 A1 · RFID transceiver sensitivity focusing system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0185540 A1 - Document ID: US20080185540A1 - Status: Published application - Kind: A1 - Application number: 11/703,301 - Filed: 2007-02-06 - Published: 2008-08-07 - Earliest claimed: 2007-02-06 - Assignees: Incom, Inc. - Inventors: Florrie Turner; Douglas Ahlers - Web page: https://patentgrep.com/patent/US20080185540A1 ## CPC - G01D 21/00: Measuring or testing not otherwise provided for - G06K 7/10079: {the collision being resolved in the spatial domain, e.g. temporary shields for blindfolding the interrogator in specific directions} - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR - G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS ## Abstract Shielding of a particular material and geometry is interposed between a radio frequency identification (“RFID”) antenna transceiver and a zone to be monitored by the antenna. The shielding has an aperture therein that to some extent defines a degree of focusing of the radio frequency (“RF”) field associated with the antenna. RFID tags having appropriate RFID circuitry are only detected by the antenna when they pass within the focused RF field. The shielding is formed of a thin metalized plastic material, such as film used in forming anti-static material for storage of sensitive electronics. One particular formulation is primarily polyethylene film with an aluminum coating or layer thereon. ## Claims ### Claim 1 A system for focusing sensitivity of an RFID transceiver, the system comprising in combination: an RFID transceiver antenna; said RFID transceiver antenna adapted to be located proximate to but spaced from a monitoring zone; said RFID transceiver antenna adapted to establish an RF field within the monitoring zone; shielding interposed between said antenna and the monitoring zone; an aperture formed in said shielding; and said shielding formed at least partially of thin plastic anti-static film. ### Claim 2 (depends on 1) The system of claim 1 wherein said plastic film includes polyethylene. ### Claim 3 (depends on 2) The system of claim 2 wherein said plastic film includes a majority polyethylene. ### Claim 4 (depends on 3) The system of claim 3 wherein said plastic film includes aluminum therein. ### Claim 5 (depends on 4) The system of claim 4 wherein said plastic film includes between ten percent and thirty-five percent polyethylene terephthalate. ### Claim 6 (depends on 5) The system of claim 5 wherein said plastic film includes less than one percent aluminum. ### Claim 7 (depends on 6) The system of claim 6 wherein said plastic film is a laminate structure including a polyethylene layer and a polyethylene terephthalate layer and with an adhesive bonding said polyethylene layer to said polyethylene terephthalate layer. ### Claim 8 (depends on 1) The system of claim 1 wherein said thin plastic anti-static film is metalized plastic film. ### Claim 9 (depends on 8) The system of claim 8 wherein said metalized plastic film includes a majority polyethylene. ### Claim 10 (depends on 8) The system of claim 8 wherein said metalized plastic film includes polyethylene terephthalate. ### Claim 11 (depends on 8) The system of claim 8 wherein said metalized plastic film includes less than one percent metal. ### Claim 12 (depends on 1) The system of claim 1 wherein said shielding is located within an enclosure along with said antenna. ### Claim 13 (depends on 12) The system of claim 12 wherein said shielding is oriented substantially in a plane, with said plane substantially perpendicular to a line extending from said antenna to a center of said monitoring zone. ### Claim 14 (depends on 1) The system of claim 1 wherein said antenna includes a body with a lower surface oriented in a substantially horizontal plane, both said body of said antenna and said shielding oriented to overlie said monitoring zone. ### Claim 15 (depends on 14) The system of claim 14 wherein said shielding is located in a substantially horizontal plane. ### Claim 16 (depends on 14) The system of claim 14 wherein said shielding includes at least two separate sheets oriented parallel with each other and spaced from each other by a distance at least as great as a width of said aperture, said separate sheets oriented non-horizontally. ### Claim 17 (depends on 16) The system of claim 16 wherein said shielding includes four separate sheets with each of said sheets oriented within a separate vertical plane and with each of said four sheets surrounding a border of said aperture, and with each of said sheets located adjacent two other sheets. ### Claim 18 A method for enhancing the reliability of an RFID tag presence monitoring system, the method including the steps of: positioning an RFID transceiver antenna proximate to, but spaced from a zone to be monitored; configuring the RFID transceiver to establish an electromagnetic field at the zone; and locating shielding between the antenna and the zone, the shielding having an aperture therein. ### Claim 19 (depends on 18) The method of claim 18 including the further step of forming the shielding at least partially of thin anti-static film. ### Claim 20 (depends on 19) The method of claim 19 wherein said anti-static film is greater than fifty percent plastic. ### Claim 21 (depends on 20) The method of claim 20 wherein said anti-static film is greater than fifty percent polyethylene. ### Claim 22 (depends on 20) The method of claim 20 wherein said anti-static film is a laminate including at least two layers with one of said layers being a polyethylene layer and with the other of said at least two layers being a polyethylene terephthalate layer. ### Claim 23 (depends on 22) The method of claim 22 wherein said anti-static film includes aluminum therein. ### Claim 24 (depends on 19) The method of claim 19 wherein said anti-static film is formed at least partially of metalized plastic. ### Claim 25 (depends on 24) The method of claim 24 wherein said forming step includes the step of forming the anti-static film to be less than ten percent aluminum, greater than fifty percent polyethylene, and between five percent and fifty percent polyethylene terephthalate. ### Claim 26 (depends on 25) The method of claim 25 wherein said forming step includes the step of forming the anti-static film to be less than one percent aluminum, greater than fifty percent polyethylene and between ten percent and thirty-five percent polyethylene terephthalate. ### Claim 27 (depends on 18) The method of claim 18 including the further step of orienting the shielding to be substantially perpendicular to a line extending from the antenna to a center of the zone to be monitored. ### Claim 28 (depends on 27) The method of claim 27 including the further step of placing the aperture along the line extending from the antenna to the center of the zone to be monitored. ### Claim 29 An RFID transceiver antenna featuring a focused RF field pattern, comprising in combination: an antenna body; shielding proximate to but spaced from said body; an aperture in said shielding; and said shielding formed at least partially of anti-static film. ### Claim 30 (depends on 29) The antenna of claim 29 wherein said shielding is formed of thin metalized plastic. ### Claim 31 (depends on 30) The antenna of claim 30 wherein said film is greater than fifty percent polyethylene. ### Claim 32 (depends on 30) The antenna of claim 30 wherein said film includes polyethylene terephthalate. ### Claim 33 (depends on 32) The antenna of claim 32 wherein said film includes both polyethylene and polyethylene terephthalate, with more polyethylene than polyethylene terephthalate. ### Claim 34 (depends on 33) The antenna of claim 33 wherein said film includes aluminum therein. ### Claim 35 (depends on 33) The antenna of claim 33 wherein said film is a laminate including at least two layers with a first layer formed primarily of polyethylene and a second layer formed primarily of polyethylene terephthalate. ### Claim 36 An attendance monitoring method, including the steps of: identifying at least one door into a room where attendance is to be tracked; having attendees wear an RFID badge including an RFID circuit therein; placing an RFID transceiver antenna adjacent the door and inside the room; configuring the RFID transceiver antenna to generate an electromagnetic field within a monitoring zone inside the door; interposing shielding between the antenna and the monitoring zone, the shielding having an aperture therein; detecting the presence of particular attendees by sensing the particular RFID badges of particular attendees as they enter the room through the door; and substantially avoiding sensing of RFID badges located outside of the door. ### Claim 37 (depends on 36) The method of claim 36 wherein said interposing shielding step includes the step of forming the shielding to be formed at least partially of anti-static film. ### Claim 38 (depends on 37) The method of claim 37 wherein said anti-static film includes metalized plastic. ### Claim 39 (depends on 37) The method of claim 37 wherein said anti-static film includes both polyethylene and polyethylene terephthalate.