# US 10,483,648 B2 · Cavity-backed annular slot antenna array > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,483,648 B2 - Document ID: US10483648B2 - Status: Granted - Kind: B2 - Application number: 15/937,395 - Filed: 2018-03-27 - Published: 2019-10-03 - Granted: 2019-11-19 - Earliest claimed: 2018-03-27 - Assignees: The MITRE Corporation - Applicants: The MITRE Corporation - Inventors: Eric D. Robinson; Ian T. McMichael - Web page: https://patentgrep.com/patent/US10483648B2 ## CPC - H01Q 13/18: the slot being backed by, or formed in boundary wall of, a resonant cavity (longitudinally slotted cylinder H01Q13/12 ){; Open cavity antennas} - H01Q 1/36: Structural form of radiating elements, e.g. cone, spiral, umbrella; {Particular materials used therewith}(H01Q1/08, H01Q1/14 take precedence) - 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 1/523: {between antennas of an array} - H01Q 13/103: {with variable reactance for tuning the antenna (tuning resonant circuits H03J)} - H01Q 21/0062: {the slots being disposed around the feeding waveguide} - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) ## Abstract Cavity backed slot antenna arrays for conformal antenna applications are provided. A cavity backed slot antenna array may include an aperture, first and second feed structures, and a backing cavity configured to support the aperture and the first and second feed structures. The aperture may have a dielectric layer and a metal layer disposed on the dielectric layer. The metal layer may have first and second annular regions. The first annular region may have a first slot region and the second annular region may have a second slot region, where the second slot region may partially overlap the first slot region. The metal layer may further include first and second radiating elements configured to radiate energy. Each of the first and second feed structures may include a central portion and a plurality of fin structures arranged radially around the central portion. ## Claims ### Claim 1 A cavity backed slot antenna array comprising: an aperture comprising a dielectric layer and a metal layer disposed on the dielectric layer, the metal layer comprising: a first annular region comprising a first slot region, a second annular region comprising a second slot region, wherein the second annular region partially overlaps the first annular region, and first and second radiating elements configured to radiate energy; a first feed structure configured to excite the first radiating element and a second feed structure configured to excite the second radiating element, each of the first and second feed structures comprising a central portion and a plurality of fin structures arranged radially around the central portion; and a backing cavity configured to support the aperture and the first and second feed structures. ### Claim 2 (depends on 1) The cavity backed slot antenna array of claim 1, wherein the first and second slot regions partially overlap each other. ### Claim 3 (depends on 1) The cavity backed slot antenna array of claim 1, wherein the aperture further comprises third and fourth annular regions arranged to partially overlap each other and the first and second annular regions; wherein the third annular region comprises a third slot region; wherein the fourth annular region comprises a fourth slot region; and wherein the first, second, third, and fourth slot regions partially overlap with each other. ### Claim 4 (depends on 1) The cavity backed slot antenna array of claim 1, wherein a lateral distance between axes of symmetry of the first and second feed structures is equal to or less than half a wavelength at a center frequency of an operating frequency band of the cavity backed slot antenna array. ### Claim 5 (depends on 1) The cavity backed slot antenna array of claim 1, wherein a lateral distance between centers of the first and second slot regions is equal to or less than half a wavelength at a center frequency of an operating frequency band of the cavity backed slot antenna array. ### Claim 6 (depends on 1) The cavity backed slot antenna array of claim 1, wherein the first slot region comprises an outer radius and an inner radius; and wherein a ratio of the outer radius to the inner radius ranges from about 1 to about 2. ### Claim 7 (depends on 1) The cavity backed slot antenna array of claim 1, wherein the first radiating element is electrically coupled to the first feed structure; and wherein the second radiating element is electrically coupled to the second feed structure. ### Claim 8 (depends on 7) The cavity backed slot antenna array of claim 7, wherein the first radiating element comprises a first radial slot; wherein the second radiating element comprises a second radial slot; and wherein the first and second radial slots are configured to direct current flow in a direction parallel to the first and second radial slots and to prevent current flow in a direction perpendicular to the first and second radial slots. ### Claim 9 (depends on 1) The cavity backed slot antenna array of claim 1, wherein each fin structure of the plurality of fin structures comprises a tapered profile. ### Claim 10 (depends on 1) The cavity backed slot antenna array of claim 1, wherein each fin structure of the plurality of fin structures comprise a hemispherical or triangular profile. ### Claim 11 (depends on 1) The cavity backed slot antenna array of claim 1, wherein the first and second feed structures are positioned within the backing cavity such that there is a minimum lateral distance between walls of the backing cavity and the first and second feed structures; and wherein the minimum lateral distance ranges from about 0.1 wavelengths to about 0.5 wavelengths at a center frequency of an operating frequency band of the cavity backed slot antenna array. ### Claim 12 (depends on 1) The cavity backed slot antenna array of claim 1, wherein the plurality of fin structures are configured to prevent coupling between the first and second feed structures. ### Claim 13 (depends on 1) The cavity backed slot antenna array of claim 1, wherein a first gap is present between the first radiating element and the first feed structure and a second is present between the second radiating element and the second feed structure; and wherein the first and second gaps prevent a short between a ground plane and the first and second radiating elements. ### Claim 14 (depends on 1) The cavity backed slot antenna array of claim 1, wherein the first and second feed structures are radially symmetrical about the central portion. ### Claim 15 A cavity backed slot antenna array comprising: an aperture comprising a plurality of slot regions arranged to partially overlap each other and a plurality of radiating elements configured to radiate energy; a plurality of feed structures configured to provide excitation to the plurality of radiating elements, each feed structure of the plurality of feed structures comprising a central portion and a plurality of fin structures arranged radially around the central portion; and a backing cavity configured to support the aperture and the plurality of feed structures. ### Claim 16 (depends on 1) The cavity backed slot antenna array of claim 1, wherein a lateral distance between centers of at least two slot regions from among the plurality of slot regions is equal to or less than half a wavelength at a center frequency of an operating frequency band of the cavity backed slot antenna array. ### Claim 17 (depends on 1) The cavity backed slot antenna array of claim 1, wherein at least one of the slot regions from among the plurality of slot regions comprises an outer radius and an inner radius; and wherein a ratio of the outer radius to the inner radius ranges from about 1 to about 2. ### Claim 18 (depends on 7) The cavity backed slot antenna array of claim 7, wherein each radiating element of the plurality of radiating elements comprises a radial slot; and wherein the radial slots are configured to direct current flow in a direction parallel to the radial slots and to prevent current flow in a direction perpendicular to the radial slots. ### Claim 19 (depends on 1) The cavity backed slot antenna array of claim 1, wherein each fin structure of the plurality of fin structures comprise a hemispherical or triangular profile. ### Claim 20 A cavity backed slot antenna array comprising: an aperture comprising: a plurality of slot regions arranged to partially overlap each other and in a rectangular or a circular array configuration, and a plurality of radiating elements configured to radiate energy; a plurality of feed structures configured to provide excitation to the plurality of radiating elements, each feed structure of the plurality of feed structures comprising a central portion and a plurality of fin structures, arranged radially around the central portion comprising a hemispherical or a triangular profile; and a backing cavity configured to support the aperture and the plurality of feed structures.