# US 12,016,164 B1 · RF filter device for aircraft nacelle access door gap > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,016,164 B1 - Document ID: US12016164B1 - Status: Granted - Kind: B1 - Application number: 18/313,724 - Filed: 2023-05-08 - Granted: 2024-06-18 - Earliest claimed: 2023-05-08 - Assignees: The Boeing Company - Applicants: The Boeing Company - Inventors: Kyu-Pyung Hwang; Thomas D. Mitchum; Philipp Andreas Boettcher; Young Song - Web page: https://patentgrep.com/patent/US12016164B1 ## CPC - H05K 9/0024: {Shield cases mounted on a PCB, e.g. cans or caps or conformal shields} - B64D 45/00: Aircraft indicators or protectors not otherwise provided for - H01Q 1/526: {Electromagnetic shields} - H01Q 15/006: {Selective devices having photonic band gap materials or materials of which the material properties are frequency dependent, e.g. perforated substrates, high-impedance surfaces} - H01Q 15/008: {said selective devices having Sievenpipers' mushroom elements} - H05K 1/0236: {Electromagnetic band-gap structures} - H05K 9/0009: {with provisions to reduce EMI leakage through the joining parts} - B64D 29/08: Inspection panels for power plants - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) ## Abstract An assembly for electromagnetic interference (EMI) shielding to prevent incident radiation from penetrating through a gap to an interior of an aircraft includes an electromagnetic band gap (EBG) structure. The EBG structure has a patch-and-via array connected to a ground layer. The EMI shielding includes a conductive adhesive and is flexible for conforming attachment to curved aircraft surfaces. The shielding may be located on a deflector plate that is parallel to an adjacent aircraft surface, on the airframe surface opposite to the deflector plate, or in both locations. The assembly filters out penetrating electromagnetic energy and prevents highly resonant cavity mode build-ups of electromagnetic energy inside a nacelle or other enclosure effectively protecting electrical equipment in the interior. ## Claims ### Claim 1 An assembly for electromagnetic interference shielding of an interior of an aircraft, comprising: a first external surface and a second external surface having an inner surface, the first external surface being contiguous with the second external surface and defining a gap therebetween; a deflector plate located in the interior, the deflector plate having a gap-facing surface parallel and adjacent to the inner surface of the second external surface; and a first shielding located on the gap-facing surface, the first shielding including a first electromagnetic band gap structure. ### Claim 2 (depends on 1) The assembly of claim 1, further comprising a second shielding located on the inner surface of the second external surface opposite from the first shielding, the second shielding including a second electromagnetic band gap structure. ### Claim 3 (depends on 1) The assembly of claim 1, further comprising an interior surface connected to the first external surface and extending toward the interior from the first external surface, the deflector plate being connected to the interior surface. ### Claim 4 (depends on 3) The assembly of claim 3, wherein the deflector plate is conductive and located beneath the gap and the second external surface. ### Claim 5 (depends on 1) The assembly of claim 1, wherein the electromagnetic band gap structure includes unit cells, each unit cell comprising a conductive patch and via connected to a ground layer. ### Claim 6 (depends on 1) The assembly of claim 1, wherein the electromagnetic band gap structure is configured to block electromagnetic radiation over a limited band gap frequency range. ### Claim 7 (depends on 1) The assembly of claim 1, wherein the first shielding includes a conductive adhesive layer. ### Claim 8 (depends on 1) The assembly of claim 1, wherein the first shielding includes a passivation layer along an outer surface of the electromagnetic band gap structure. ### Claim 9 (depends on 1) The assembly of claim 1, wherein the interior is an interior of a nacelle and the second external surface is a nacelle access door. ### Claim 10 (depends on 1) The assembly of claim 1, further including avionics equipment in the interior. ### Claim 11 (depends on 1) The assembly of claim 1, wherein the gap-facing surface of the deflector plate and the inner surface of the second external surface define a distance therebetween configured to establish a parallel plate mode in electromagnetic waves entering the interior through the gap. ### Claim 12 An assembly for electromagnetic interference shielding of an interior of an aircraft, comprising: a first external surface and a second external surface having an inner surface, the first external surface being contiguous with the second external surface and defining a gap therebetween; a deflector plate located in the interior and having a gap-facing surface parallel to and opposite from the inner surface of the second external surface; and a first shielding located on the inner surface of the second external surface, the first shielding including a first electromagnetic band gap structure. ### Claim 13 (depends on 12) The assembly of claim 12, wherein the first shielding includes a first edge and a second edge defining a width of the first shielding, the first edge located near the gap and the second edge located distally from the gap. ### Claim 14 (depends on 13) The assembly of claim 13, wherein the first shielding includes a length perpendicular to the width, and the length extending along at least a portion of a perimeter of the second external surface. ### Claim 15 (depends on 14) The assembly of claim 14, wherein the first shielding includes unit cells arrayed along the length and the width of the first shielding, each unit cell comprising a conductive patch and via connected to a ground layer and a dielectric substrate layer extending from the conductive patch to the ground layer. ### Claim 16 Electromagnetic interference shielding, comprising: an electromagnetic band gap structure including: an array of unit cells across a length and a width, each unit cell comprising: a flat conductive patch parallel to the length and width; each patch having an inner surface; and a conductive via connected to the inner surface of the patch; a conductive ground layer having an inner surface and an outer surface; the conductive via extending from the patch to the inner surface of ground layer; a substrate layer of dielectric material located between the patches and the ground layer; and a conductive adhesive layer connected to the outer surface of the ground layer. ### Claim 17 (depends on 16) The shielding of claim 16, wherein the shielding is flexible. ### Claim 18 (depends on 16) The shielding of claim 16, wherein the patch has a polygonal shape. ### Claim 19 (depends on 16) The shielding of claim 16, further including a passivation layer on a top surface of the electromagnetic band gap structure. ### Claim 20 (depends on 16) The shielding of claim 16, wherein the electromagnetic band gap structure is configured to block electromagnetic radiation over a limited band gap frequency range.