# US 2021/0280984 A1 · Antenna > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0280984 A1 - Document ID: US20210280984A1 - Status: Published application - Kind: A1 - Application number: 17/187,494 - Filed: 2021-02-26 - Published: 2021-09-09 - Earliest claimed: 2020-03-04 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Yu Tanaka - Web page: https://patentgrep.com/patent/US20210280984A1 ## CPC - H01Q 21/245: {provided with means for varying the polarisation (polarising devices H01Q15/24; tracking by comparing linear polarisation compounds G01S3/146; reducing depolarisation effects H04B7/00; polarisation diversity H04B7/10)} - H01Q 1/2216: {used in interrogator/reader equipment} - H01Q 1/38: formed by a conductive layer on an insulating support {(patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142)} - H01Q 3/24: varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching - H01Q 3/247: {by switching different parts of a primary active element} - H01Q 9/42: with folded element, the folded parts being spaced apart a small fraction of the operating wavelength - H01Q 21/0075: {Stripline fed arrays (H01Q21/065 takes precedence)} - H01Q 21/061: {Two dimensional planar arrays} - H01Q 21/24: Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction {(circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001)} - H01Q 1/273: {Adaptation for carrying or wearing by persons or animals} - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) ## Abstract An antenna includes a control unit and first to Nth antenna elements. N is an integer that is four or more. The control unit controls input of signals to each antenna element. Among each antenna element, open ends of the second to Nth antenna elements extend in directions different from a direction in which the first antenna element extends. Among signals input to each antenna element, signals input to the second to Nth antenna elements have phases different from a phase of a signal input to the first antenna element. The control unit controls a state to be in a first state, where signals are input to each antenna element to radiate a circularly polarized wave in a first direction or a second state, where signals are input to one or more of the antenna elements to radiate a linearly polarized wave in a direction different from the first direction. ## Claims ### Claim 1 An antenna comprising: first to Nth antenna elements, where N is an integer that is four or more; and a control unit configured to control input of signals to each of the first to Nth antenna elements, wherein, among the first to Nth antenna elements, open ends of the second to Nth antenna elements extend in directions substantially 360/N degrees different from a direction in which the first antenna element extends, wherein, among signals input to the first to Nth antenna elements, signals input to the second to Nth antenna elements have phases that are substantially 360/N degrees different from a phase of a signal input to the first antenna element, and wherein the control unit controls input of signals in such a manner as to control a state to be a first state or a second state, wherein the first state is a state in which signals are input to the first to Nth antenna elements to radiate a circularly polarized wave in a first direction, and the second state is a state in which signals are input to one or more of the first to Nth antenna elements to radiate a linearly polarized wave in a direction different from the first direction. ### Claim 2 (depends on 1) The antenna according to claim 1, wherein, in a case where antenna elements, to which signals that have phases that are substantially 90 degrees, 180 degrees, and 270 degrees different from a phase of the first antenna element are input, are a second antenna element, a third antenna element, and a fourth antenna element, respectively, the control unit controls the state to be the first state in which the signals are input to the first, second, third, and fourth antenna elements to radiate the circularly polarized wave in the first direction or the second state in which the signals are input to the first and third antenna elements but not input to the second and fourth antenna elements to radiate the linearly polarized wave in the direction different from the first direction. ### Claim 3 (depends on 2) The antenna according to claim 2, wherein the control unit controls the state to be a third state in which the signals are input to the second and fourth antenna elements but not input to the first and third antenna elements to radiate a linearly polarized wave in a direction different from the first and second directions. ### Claim 4 (depends on 1) The antenna according to claim 1, wherein the first to Nth antenna elements are provided on a first substrate, each side of which has a length of λ/4, wherein the control unit is provided on a second substrate, each side of which has a length of λ/4, and wherein the first substrate and the second substrate are separated in parallel with each other and at a distance of substantially λ/8. ### Claim 5 (depends on 1) The antenna according to claim 1, further comprising at least one sensor selected from the following: an acceleration sensor, a geomagnetic sensor, a global positioning system, or a reflected power sensor, wherein the control unit controls input of signals to the first to Nth antenna elements based on a detection result or detection results from the at least one sensor. ### Claim 6 (depends on 1) The antenna according to claim 1, wherein the control unit controls input of signals to the first to Nth antenna elements in accordance with a received response signal or a timer. ### Claim 7 (depends on 1) The antenna according to claim 1, wherein the antenna is configured to perform radio-frequency identifier (RFID) communication. ### Claim 8 (depends on 1) A communication device comprising the antenna according to claim 1. ### Claim 9 A method for an antenna having first to Nth antenna elements, where N is an integer that is four or more, the method comprising: controlling input of signals to each of the first to Nth antenna elements, wherein, among the first to Nth antenna elements, open ends of the second to Nth antenna elements extend in directions substantially 360/N degrees different from a direction in which the first antenna element extends, wherein, among signals input to the first to Nth antenna elements, signals input to the second to Nth antenna elements have phases that are substantially 360/N degrees different from a phase of a signal input to the first antenna element, and wherein controlling input of signals includes controlling a state to be a first state or a second state, wherein the first state is a state in which signals are input to the first to Nth antenna elements to radiate a circularly polarized wave in a first direction, and the second state is a state in which signals are input to one or more of the first to Nth antenna elements to radiate a linearly polarized wave in a direction different from the first direction. ### Claim 10 A non-transitory computer-readable storage medium storing a program to cause a computer to perform a method for an antenna having first to Nth antenna elements, where N is an integer that is four or more, the method comprising: controlling input of signals to each of the first to Nth antenna elements, wherein, among the first to Nth antenna elements, open ends of the second to Nth antenna elements extend in directions substantially 360/N degrees different from a direction in which the first antenna element extends, wherein, among signals input to the first to Nth antenna elements, signals input to the second to Nth antenna elements have phases that are substantially 360/N degrees different from a phase of a signal input to the first antenna element, and wherein controlling input of signals includes controlling a state to be a first state or a second state, wherein the first state is a state in which signals are input to the first to Nth antenna elements to radiate a circularly polarized wave in a first direction, and the second state is a state in which signals are input to one or more of the first to Nth antenna elements to radiate a linearly polarized wave in a direction different from the first direction.