# US 12,015,203 B2 · Transparent stealth structure > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,015,203 B2 - Document ID: US12015203B2 - Status: Granted - Kind: B2 - Application number: 17/621,225 - Filed: 2019-07-23 - Published: 2022-11-03 - Granted: 2024-06-18 - Earliest claimed: 2019-07-19 - Assignees: Center for Advanced Meta-Materials - Applicants: Center for Advanced Meta-Materials - Inventors: Yong June Kim; Hyun June Jung; Se Jeong Won; Hak Joo Lee - Web page: https://patentgrep.com/patent/US12015203B2 ## CPC - H01Q 17/001: {for modifying the directional characteristic of an aerial} - H01Q 15/0026: {said selective devices having a stacked geometry or having multiple layers} - H01Q 15/0086: {said selective devices having materials with a synthesized negative refractive index, e.g. metamaterials or left-handed materials} - H01Q 17/00: Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) ## Abstract A transparent stealth structure includes: a first transparent film structure stacked on a front surface of a transparent base, the first transparent film structure causing energy loss of incident electromagnetic waves having a target frequency to change a phase of transmitted electromagnetic waves propagating toward the transparent base; and a second transparent film structure stacked on a back surface of a transparent base, the second transparent film structure reflecting the transmitted electromagnetic waves having passed through the transparent base while adjusting a phase of reflected waves propagating toward the first transparent film structure, wherein the first transparent film structure includes a first front transparent conductive pattern having a first sheet resistance and a second front transparent conductive pattern filling a region, and the second transparent film structure includes a first rear transparent conductive pattern having a third sheet resistance and a second rear transparent conductive pattern filling a region. ## Claims ### Claim 1 A transparent stealth structure comprising: a first transparent film structure stacked on a front surface of a transparent base, the first transparent film structure causing energy loss of incident electromagnetic waves having a target frequency to change a phase of transmitted electromagnetic waves propagating toward the transparent base; and a second transparent film structure stacked on a back surface of the transparent base, the second transparent film structure reflecting the transmitted electromagnetic waves having passed through the transparent base while adjusting a phase of reflected waves propagating toward the first transparent film structure, wherein the first transparent film structure comprises a first front transparent conductive pattern having a first sheet resistance and a second front transparent conductive pattern filling a region without the first front transparent conductive pattern in the first transparent film structure and having a second sheet resistance greater than the first sheet resistance, and the second transparent film structure comprises a first rear transparent conductive pattern having a third sheet resistance and a second rear transparent conductive pattern filling a region without the first rear transparent conductive pattern in the second transparent film structure and having a fourth sheet resistance greater than the third sheet resistance, wherein a bottom surface of the first front transparent conductive pattern and a bottom surface of the second front transparent conductive pattern are in direct contact with the front surface of the transparent base, and a top surface of the first rear transparent conductive pattern and a top surface of the second rear transparent conductive pattern are in direct contact with the back surface the transparent base. ### Claim 2 (depends on 1) The transparent stealth structure according to claim 1, wherein the first front transparent conductive pattern and the second front transparent conductive pattern have the same thickness. ### Claim 3 (depends on 1) The transparent stealth structure according to claim 1, wherein an allowable range of a difference between a first transmittance of the first front transparent conductive pattern and a second transmittance of the second front transparent conductive pattern is set such that the first front transparent conductive pattern and the second front transparent conductive pattern are visually indistinguishable from each other. ### Claim 4 (depends on 3) The transparent stealth structure according to claim 3, wherein the allowable range of the difference between the first transmittance and the second transmittance is less than 1.7%. ### Claim 5 (depends on 1) The transparent stealth structure according to claim 1, wherein an allowable range of a ratio of the second sheet resistance to the first sheet resistance is set such that the second front transparent conductive pattern is prevented from affecting electrical performance of the first front transparent conductive pattern. ### Claim 6 (depends on 5) The transparent stealth structure according to claim 5, wherein the allowable range of the ratio of the second sheet resistance to the first sheet resistance is 6.25 or more. ### Claim 7 (depends on 5) The transparent stealth structure according to claim 5, wherein the first sheet resistance is greater than 60 ohm/sq and less than 160 ohm/sq. ### Claim 8 (depends on 5) The transparent stealth structure according to claim 5, wherein the second sheet resistance is greater than or equal to 1,000 ohm/sq. ### Claim 9 (depends on 1) The transparent stealth structure according to claim 1, wherein the first front transparent conductive pattern and the second front transparent conductive pattern are formed of graphene. ### Claim 10 (depends on 1) The transparent stealth structure according to claim 1, wherein the first sheet resistance is greater than or equal to the third sheet resistance, and the second sheet resistance is equal to the fourth sheet resistance. ### Claim 11 (depends on 1) The transparent stealth structure according to claim 1, wherein the transparent base is a dielectric base.