# US 2013/0154803 A1 · Method and apparatus for improving radio frequency identification coverage > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0154803 A1 - Document ID: US20130154803A1 - Status: Published application - Kind: A1 - Application number: 13/329,438 - Filed: 2011-12-19 - Published: 2013-06-20 - Earliest claimed: 2011-12-19 - Assignees: Symbol Technologies, Inc. - Inventors: MICHAEL J. KOCH - Web page: https://patentgrep.com/patent/US20130154803A1 ## CPC - G06K 7/10356: {using a plurality of antennas, e.g. configurations including means to resolve interference between the plurality of antennas} - H01Q 1/2216: {used in interrogator/reader equipment} - H01Q 3/247: {by switching different parts of a primary active element} - H04B 7/0617: {for beam forming} - H01Q 3/26: varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture ({H01Q3/12,} H01Q3/22, H01Q3/24 take precedence) - H04B 7/0691: {using subgroups of transmit antennas} - H04B 7/10: Polarisation diversity; Directional diversity - G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) - H04B: TRANSMISSION ## Abstract A method and apparatus are disclosed for improving RFID coverage using an antenna array having an adaptive antenna beam. The apparatus includes an RFID reader including an antenna array having a plurality of antenna elements. Subsets of the plurality of antenna elements are selectively activating in order to direct an antenna beam to communicate with at least one RFID tag. The method includes transmitting an interrogation signal from an antenna array by activating one or more subsets of a plurality of antenna elements forming the antenna array. In this way, the interrogation signal is directed thereby improving antenna coverage. ## Claims ### Claim 1 A radio frequency identification (RFID) reader, comprising: an antenna array including a plurality of antenna elements; one or more transmit/receive modules coupled to the plurality of antenna elements; and a beam forming processor coupled to the one or more transmit/receive modules for selectively activating one or more subsets of the plurality of antenna elements, wherein the selectively activated subsets of the plurality of antenna elements direct a transmission beam capable of interrogating at least one RFID tag. ### Claim 2 (depends on 1) The RFID reader of claim 1, wherein the plurality of antenna elements are spaced approximately one-half wavelength apart. ### Claim 3 (depends on 1) The RFID reader of claim 1, which includes a controller coupled to the beam forming processor. ### Claim 4 (depends on 1) The RFID reader of claim 1, wherein the beam forming processor selectively activates the one or more subsets of the plurality of antenna elements to collectively activate all of the plurality of antenna elements. ### Claim 5 (depends on 1) The RFID reader of claim 1, wherein the plurality of antenna elements comprises one or more antenna types from the following group of antenna types: monopole, dipole, loop, helical and patch. ### Claim 6 (depends on 5) The RFID reader of claim 5, wherein the plurality of antenna elements are polarized with one or more of the following group of antenna polarizations: vertical, horizontal and circular. ### Claim 7 (depends on 1) The RFID reader of claim 1, wherein the RFID reader receives a signal from the at least one RFID tag via the one or more subsets of the plurality of antenna elements. ### Claim 8 (depends on 1) The RFID reader of claim 1, wherein the RFID reader activates a first subset of the one or more subsets of the plurality of antenna elements to transmit an interrogation signal and a second subset of the one or more subsets of the plurality of antenna elements to receive a signal from the at least one RFID tag. ### Claim 9 (depends on 8) The RFID reader of claim 8, wherein the first subset and the second subset have a common polarization for the respective transmitting and receiving. ### Claim 10 (depends on 8) The RFID reader of claim 8, wherein the first subset and the second subset have different polarization for the respective transmitting and receiving. ### Claim 11 (depends on 1) The RFID reader of claim 1, wherein the RFID reader, and at least one other RFID reader, are coupled to a controller used for controlling the plurality of RFID readers. ### Claim 12 A radio frequency identification (RFID) reader, comprising: an antenna array including a plurality of antenna elements; one or more transmit/receive module coupled to the plurality of antenna elements; and a beam forming processor coupled to the one or more transmit/receive modules for selectively activating one or more subsets of the plurality of antenna elements, wherein the selectively activated subsets of the plurality of antenna elements direct an antenna beam to receive a signal from at least one RFID tag. ### Claim 13 (depends on 12) The RFID reader of claim 12, wherein the plurality of antenna elements are spaced approximately one-half wavelength apart. ### Claim 14 (depends on 12) The RFID reader of claim 12, which includes a controller coupled to the beam forming processor. ### Claim 15 (depends on 12) The RFID reader of claim 12, wherein the plurality of antenna elements comprises one or more antenna types from the following group of antenna types: monopole, dipole, loop, helical and patch. ### Claim 16 (depends on 12) The RFID reader of claim 12, wherein the RFID reader, and at least one other RFID reader, are coupled to a controller used for controlling the plurality of RFID readers. ### Claim 17 (depends on 12) The RFID reader of claim 12, wherein the RFID reader initially activates a first subset of the one or more subsets of the plurality of antenna elements to transmit an interrogation signal and a second subset of the one or more subsets of the plurality of antenna elements to receive the signal from the at least one RFID tag, the first and second subsets having a different polarization. ### Claim 18 A method, comprising: activating one or more subsets of a plurality of antenna elements forming an antenna array to direct an antenna beam for transmitting a radio frequency identification (RFID) interrogation signal from the antenna array, whereby, the RFID interrogation signal is directed by varying parameters of the transmission beam via subset selection of the one or more subsets of the plurality of antenna elements. ### Claim 19 (depends on 18) The method of claim 18, further comprising receiving a responsive signal from an RFID tag via the one or more subsets of the plurality of antenna elements. ### Claim 20 (depends on 18) The method of claim 18, further comprising receiving a responsive signal from an RFID tag via activating a different subset of the one or more subsets of the plurality of antenna elements than was used to transmit the interrogation signal.