# US 2026/0074431 A1 · Frequency selective surface structure > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2026/0074431 A1 - Document ID: US20260074431A1 - Status: Published application - Kind: A1 - Application number: 18/984,493 - Filed: 2024-12-17 - Published: 2026-03-12 - Earliest claimed: 2024-09-10 - Assignees: Inventec (Pudong) Technology Corporation; Inventec Corporation - Applicants: Inventec (Pudong) Technology Corporation; Inventec Corporation - Inventors: Po-Han CHEN; Hao-Hsiang WANG; Yu Shu TAI; Hsin-Hung LIN; Wei-Chen CHENG - Web page: https://patentgrep.com/patent/US20260074431A1 ## CPC - H01Q 15/0013: {said selective devices working as frequency-selective reflecting surfaces, e.g. FSS, dichroic plates, surfaces being partly transmissive and reflective} - H01Q 15/0026: {said selective devices having a stacked geometry or having multiple layers} - H01Q 9/0407: {Substantially flat resonant element parallel to ground plane, e.g. patch antenna (dipole H01Q9/285; monopole H01Q9/40)} - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) ## Abstract The invention provides a frequency selective surface structure including a substrate and at least one conductive layer. The at least one conductive layer is disposed on the substrate and includes four central double-frequency patches. The four central double-frequency patches are spaced apart from one another and are arranged in a 2×2 array. In each of the four central double-frequency patches, the central double-frequency patch is in a polygonal shape and has a central corner part, a plurality of outer corner parts and a plurality of notches, the central corner part is located closer to a geometric center of the at least one conductive layer than the plurality of outer corner parts, and the plurality of notches are located on the plurality of outer corner parts, respectively. ## Claims ### Claim 1 A frequency selective surface structure, comprising: a substrate; and at least one conductive layer, disposed on the substrate and comprising four central double-frequency patches, wherein the four central double-frequency patches are spaced apart from one another and are arranged in a 2×2 array; wherein, in each of the four central double-frequency patches, the central double-frequency patch is in a polygonal shape and has a central corner part, a plurality of outer corner parts and a plurality of notches, the central corner part is located closer to a geometric center of the at least one conductive layer than the plurality of outer corner parts, and the plurality of notches are located on the plurality of outer corner parts, respectively. ### Claim 2 (depends on 1) The frequency selective surface structure according to claim 1, wherein in each of the four central double-frequency patches, the plurality of outer corner parts comprises three outer corner parts and the plurality of notches comprises three notches, the central double-frequency patch further has four outer edges, and extension lines of the four outer edges intersect with one another and together form an outer peripheral region that is in a rectangular shape. ### Claim 3 (depends on 2) The frequency selective surface structure according to claim 2, wherein in each of the four central double-frequency patches, the plurality of notches are in a square shape, a length and a width of the outer peripheral region are 4.5 millimeter (mm) and 3.5 mm, respectively, and a width of the plurality of notches is 1 mm. ### Claim 4 (depends on 1) The frequency selective surface structure according to claim 1, wherein in each of the four central double-frequency patches, the central double-frequency patch further has a slot that is spaced apart from the central corner part and the plurality of outer corner parts. ### Claim 5 (depends on 4) The frequency selective surface structure according to claim 4, wherein the slot of each of the four central double-frequency patches is in a square shape. ### Claim 6 (depends on 1) The frequency selective surface structure according to claim 1, wherein the at least one conductive layer further comprises a high-frequency patch, the substrate has an outer surface, the at least one conductive layer is disposed on the outer surface, the outer surface is in a polygonal shape and has a plurality of substrate corner parts, the high-frequency patch comprises a peripheral part and a plurality of protruding parts, the plurality of protruding parts protrude inwards from the peripheral part, the peripheral part is located on an outer edge of the outer surface and surrounds the plurality of protruding parts and the four central double-frequency patches, and the plurality of protruding parts are located on the plurality of substrate corner parts, respectively. ### Claim 7 (depends on 6) The frequency selective surface structure according to claim 6, wherein the at least one conductive layer further comprises two low-frequency patches, the two low-frequency patches are spaced apart from the four central double-frequency patches and the high-frequency patch, in each of the two low-frequency patches, the low-frequency patch comprises a first frequency selective bar and a second frequency selective bar that are partially overlapped in an overlapped region, an extension direction of the first frequency selective bar is perpendicular to an extension direction of the second frequency selective bar, a width of the first frequency selective bar is larger than a width of the second frequency selective bar, and the four central double-frequency patches are located between the two second frequency selective bars of the two low-frequency patches. ### Claim 8 (depends on 7) The frequency selective surface structure according to claim 7, wherein in each of the two low-frequency patches, a length by which the first frequency selective bar protrudes toward the geometric center of the at least one conductive layer from the overlapped region is longer than a length by which the first frequency selective bar protrudes away from the geometric center of the at least one conductive layer from the overlapped region. ### Claim 9 (depends on 7) The frequency selective surface structure according to claim 7, wherein in each of the two low-frequency patches, a part of the first frequency selective bar is located between two adjacent ones of the four central double-frequency patches. ### Claim 10 (depends on 1) The frequency selective surface structure according to claim 1, wherein the at least one conductive layer comprises a plurality of conductive layers that are arranged in a 10×10 array on the substrate.