# US 11,308,379 B2 · RFID tags with shielding structure for incorporation into microwavable food packaging > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,308,379 B2 - Document ID: US11308379B2 - Status: Granted - Kind: B2 - Application number: 15/856,502 - Filed: 2017-12-28 - Published: 2018-07-05 - Granted: 2022-04-19 - Earliest claimed: 2016-12-29 - Assignees: Avery Dennison Retail Information Services LLC - Applicants: Avery Dennison Retail Information Services, LLC - Inventors: Ian J. Forster; Norman Howard; Brad Cumby; James Orlowski; Brian Strohmeier; Hu Duan; Cameron Higgins; John Feltz - Web page: https://patentgrep.com/patent/US11308379B2 ## CPC - G06K 19/0773: {the record carrier comprising means to protect itself against external heat sources} - B65D 81/3446: {specially adapted to be heated by microwaves} - B65D 81/3453: {Rigid containers, e.g. trays, bottles, boxes, cups} - G06K 19/0715: {the arrangement including means to regulate power transfer to the integrated circuit} - G06K 19/0723: {the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs} - G06K 19/07752: {using an interposer} - G06K 19/07771: {the record carrier comprising means for minimising adverse effects on the data communication capability of the record carrier, e.g. minimising Eddy currents induced in a proximate metal or otherwise electromagnetically interfering object} - G06K 19/07775: {the antenna being on-chip} - G06K 19/07786: {the antenna being of the HF type, such as a dipole} - G06K 19/07798: {part of the antenna or the integrated circuit being adapted for rupturing or breaking, e.g. record carriers functioning as sealing devices for detecting not-authenticated opening of containers (electronic seals G09F3/03)} - B65D 2203/10: Transponders - G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS - B65D: CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES ## Abstract RFID tags are provided for incorporation into the packaging of a microwavable food item, with the RFID tag being configured to be safely microwaved. The RFID tag includes an antenna defining a gap and configured to operate at a first frequency. An RFID chip is electrically coupled to the antenna across the gap. A shielding structure is electrically coupled to the antenna across the gap and overlays the RFID chip. The shielding structure includes a shield conductor and a shield dielectric at least partially positioned between the shield conductor and the RFID chip. The shielding structure is configured to limit the voltage across the gap when the antenna is exposed to a second frequency that is greater than first frequency. In additional embodiments, RFID tags are provided for incorporation into the packaging of a microwavable food item, with the RFID tag being configured to be safely microwaved. The RFID tag includes an RFID chip and an antenna electrically coupled to the RFID chip. The antenna may have a sheet resistance in the range of approximately 100 ohms to approximately 230 ohms, optionally with an optical density in the range of approximately 0.18 to approximately 0.29. Alternatively, or additionally, the antenna may be configured to fracture into multiple pieces upon being subjected to heating in a microwave oven. Alternatively, or additionally, the RFID tag may be incorporated in an RFID label that is secured to the package by a joinder material with a greater resistance than that of the antenna, such as a sheet resistance in the range of approximately 100 ohms to approximately 230 ohms. ## Claims ### Claim 1 An RFID tag comprising: an antenna defining a gap and configured to operate at a first frequency; an RFID chip electrically coupled to the antenna across the gap; and a shielding structure electrically coupled to the antenna across the gap, overlaying the RFID chip, and comprising a shield conductor, and a shield dielectric at least partially positioned between the shield conductor and the RFID chip, wherein the shielding structure is configured to limit the voltage across the gap when the antenna is exposed to a second frequency greater than the first frequency. ### Claim 2 (depends on 1) The RFID tag of claim 1, wherein the shield dielectric is incorporated into an over-lamination layer. ### Claim 3 (depends on 1) The RFID tag of claim 1, wherein the shielding structure is incorporated into an RFID strap. ### Claim 4 (depends on 1) The RFID tag of claim 1, wherein the shield conductor includes an extended area configured to dissipate heat generated across the gap and oriented so as not to overlie the antenna and the gap. ### Claim 5 (depends on 4) The RFID tag of claim 4, wherein the shield conductor is formed of a non-flammable material. ### Claim 6 (depends on 1) The RFID tag of claim 1, wherein the shield dielectric is formed of a material configured to undergo a reversible or non-reversible dielectric breakdown when the antenna is exposed to the second frequency. ### Claim 7 (depends on 1) The RFID tag of claim 1, wherein the shield conductor comprises a conductive material printed onto the shield dielectric. ### Claim 8 (depends on 1) The RFID tag of claim 1, further comprising a second shielding structure electrically coupled to the antenna across the gap, underlaying the RFID chip, and comprising a second shield conductor, and a second shield dielectric at least partially positioned between the second shield conductor and the antenna. ### Claim 9 Packaging for a microwavable food item comprising: an enclosure; and an RFID tag secured to the enclosure and including an antenna defining a gap and configured to operate at a first frequency, an RFID chip electrically coupled to the antenna across the gap, and a shielding structure electrically coupled to the antenna across the gap, overlaying the RFID chip, and comprising a shield conductor, and a shield dielectric at least partially positioned between the shield conductor and the RFID chip, wherein the shielding structure is configured to limit the voltage across the gap when the antenna is exposed to a second frequency greater than the first frequency. ### Claim 10 (depends on 9) The packaging of claim 9, wherein the shield dielectric is incorporated into an over-lamination layer. ### Claim 11 (depends on 9) The packaging of claim 9, wherein the shielding structure is incorporated into an RFID strap. ### Claim 12 (depends on 9) The packaging of claim 9, wherein the shield conductor includes an extended area configured to dissipate heat generated across the gap and oriented so as not to overlie the antenna and the gap. ### Claim 13 (depends on 9) The packaging of claim 9, wherein the shield dielectric is formed of a material configured to undergo a reversible or non-reversible dielectric breakdown when the antenna is exposed to the second frequency. ### Claim 14 (depends on 9) The packaging of claim 9, further comprising a second shielding structure electrically coupled to the antenna across the gap, positioned between the antenna and the enclosure, and comprising a second shield conductor, and a second shield dielectric at least partially positioned between the second shield conductor and the antenna.