# US 11,909,436 B1 · Methods and tunable apparatuses for dynamic dispersion compensation of electromagnetic signals > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,909,436 B1 - Document ID: US11909436B1 - Status: Granted - Kind: B1 - Application number: 17/867,243 - Filed: 2022-07-18 - Granted: 2024-02-20 - Earliest claimed: 2019-09-10 - Assignees: The Board of Regents for the Oklahoma Agricultural and Mechanical Colleges - Applicants: The Board of Regents for the Oklahoma Agricultural and Mechanical Colleges - Inventors: John F. O'Hara; Karl Louthan Strecker - Web page: https://patentgrep.com/patent/US11909436B1 ## CPC - H01Q 15/14: Reflecting surfaces; Equivalent structures {(electromagnetic shields H01Q1/526)} - H04B 1/719: Interference-related aspects - H01Q 19/104: {using a substantially flat reflector for deflecting the radiated beam, e.g. periscopic antennas (periscopic fed Cassegrain antennas H01Q19/191; passive relays H04B7/145)} - H04B 1/71632: {Signal aspects (H04B1/7172 and H04B1/7176 take precedence)} - H04B 1/71635: {Transmitter aspects (H04B1/7174 takes precedence)} - H04B 1/71637: {Receiver aspects (H04B1/7183 takes precedence)} - H04B 1/7174: {Pulse generation (in general H04L25/03834)} - H04B 1/7172: {Pulse shape (in general H04L25/03834)} - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) - H04B: TRANSMISSION ## Abstract In ultra-wideband or impulse radio terahertz wireless communication, the electromagnetic signal may experience group delay dispersion (GDD). Without correction, this can degrade the achievable data transmission rate. An apparatus comprising a stratified structure having a front portion and a back portion is disclosed. The structure comprises a plurality of adjacent layers of differing refractive indices, wherein each layer has a refractive index different from an immediately adjacent layer. The structure further includes a backing layer at the back portion. The structure defines a GDD, which can be adjusted, and the structure is configured to introduce the GDD to an incident electromagnetic signal and thereby produce a dispersion-compensated electromagnetic signal when the incident signal is reflected by the structure. The GDD of the structure is configured to substantially cancel out the dispersive effects experienced by the electromagnetic signal in the signal path. ## Claims ### Claim 1 An apparatus comprising: a stratified structure having a front portion and a back portion, the stratified structure comprising a plurality of adjacent layers of differing refractive indices, wherein each layer has a refractive index different from an immediately adjacent layer, the stratified structure further including a backing layer at the back portion; the stratified structure defining a group delay dispersion, and the stratified structure is configured to introduce the group delay dispersion to an electromagnetic signal incident upon the stratified structure and thereby produce a dispersion-compensated electromagnetic signal when the incident electromagnetic signal is reflected by the stratified structure. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the group delay dispersion of the stratified structure is dynamically tunable by at least one of: rotation of the stratified structure, adjustment of a thickness of at least one of the plurality of adjacent layers of the stratified structures, or one or more combinations of any of the foregoing, wherein rotation of the stratified structure changes an angle of incidence upon which the incident electromagnetic signal encounters the stratified structure and thereby changes the group delay dispersion of the stratified structure, wherein a change to a thickness of one or more of the plurality of adjacent layers of the stratified structure thereby changes the group delay dispersion of the stratified structure. ### Claim 3 (depends on 2) The apparatus of claim 2, wherein when one or more of the plurality of adjacent layers is a fluid, and a thickness of at least one of the one or more of the plurality of adjacent layers of the fluid is about 1 micrometer to about 2,000 micrometers. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the group delay dispersion introduced to the incident electromagnetic signal is substantially opposite to a group delay dispersion caused, in part, by at least one or more signal dispersion-causing mechanisms experienced along a signal path of the electromagnetic signal. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein at least one layer of the plurality of adjacent layers is a frequency-selective surface and at least one layer of the plurality of adjacent layers is a dielectric substrate. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the incident electromagnetic signal has a carrier frequency between about 0.1 terahertz to about 10 terahertz. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein information represented by the dispersion-compensated electromagnetic signal substantially corresponds to information represented by an initial electromagnetic signal absent experiencing dispersive effects. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein the plurality of adjacent layers is selected from one or more of: silicon, sapphire, quartz, polytetrafluoroethylene, polyimide, polystyrene, cyclo-olefin polymer, cyclo-olefin copolymer, polydimethylsiloxane, parylene, low-loss plastic, polyethylene, polymethyl methacrylate, low-loss resin, low-loss glasses, low-loss ceramic, titanium dioxide, oil, air, nitrogen, helium, neon, argon, or combinations of any of the foregoing. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein the backing layer is a frequency-selective surface or a reflective metal. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the reflective metal is selected from the group of aluminum, gold, silver, copper, titanium, nickel, cobalt, chromium, molybdenum, platinum, tungsten, or alloys of any of the foregoing. ### Claim 11 (depends on 1) The apparatus of claim 1, further comprising a plurality of stratified structures to form a cohort of stratified structures and the plurality of stratified structures are arranged relative to each other to communicate the incident electromagnetic signal, and the cohort defines a group delay dispersion of the cohort. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein the cohort further comprises at least one moveable reflective layer, the moveable reflective layer is configured to move from a first position to a second position where the second position blocks a front portion of at least one stratified structure in the cohort and thereby change the group delay dispersion of the cohort. ### Claim 13 (depends on 11) The apparatus of claim 11, wherein an angle of incidence for each stratified structure of the cohort is between about 0 degrees and about 90 degrees. ### Claim 14 (depends on 13) The apparatus of claim 13, wherein an angle of incidence for each stratified structure of the cohort is between about 0 degrees and about 45 degrees. ### Claim 15 (depends on 11) The apparatus of claim 11, wherein the stratified structure is dynamically tunable by rotation of at least one stratified structure of the cohort, placement of a moveable reflective layer on the front portion of at least one of the stratified structures of the cohort, adjustment of a thickness of at least one of the plurality of adjacent layers of one or more of the stratified structures of the cohort, or one or more combinations of any of the foregoing. ### Claim 16 A dynamic dispersion compensator comprising: a cohort of a plurality of stratified structures arranged relative to each other to communicate an incident electromagnetic signal, wherein the cohort defines a group delay dispersion of the cohort and the cohort is configured to introduce a group delay dispersion to the incident electromagnetic signal and reflect a modified electromagnetic signal, wherein each stratified structure in the cohort includes a front portion and a back portion, and each stratified structure includes a plurality of adjacent layers, and each layer has a refractive index different from an immediately adjacent layer, and each stratified structure includes a backing layer at its back portion, wherein each stratified structure in the cohort defines a group delay dispersion for itself, and wherein the dynamic dispersion compensator configured to be dynamically tunable. ### Claim 17 (depends on 16) The dynamic dispersion compensator of claim 16, wherein the cohort further includes at least one moveable reflective layer, and wherein the at least one moveable reflective layer of the cohort is configured to move from a first position to a second position where the second position blocks the front portion of at least one stratified structure in the cohort and thereby changes the group delay dispersion of the cohort. ### Claim 18 (depends on 16) The dynamic dispersion compensator of claim 16, wherein the group delay dispersion introduced to the incident electromagnetic signal by the cohort is substantially opposite to a group delay dispersion caused in part, by at least one or more signal dispersion-causing mechanisms experienced along a signal path of the incident electromagnetic signal. ### Claim 19 (depends on 16) The dynamic dispersion compensator of claim 16, wherein information represented by the modified electromagnetic signal substantially corresponds to information represented by an initial electromagnetic signal absent experiencing dispersive effects along a signal path of the incident electromagnetic signal. ### Claim 20 (depends on 16) The dynamic dispersion compensator of claim 16, wherein the plurality of adjacent layers of each of the plurality of stratified structures in the cohort is selected from one or more of: silicon, sapphire, quartz, polytetrafluoroethylene, polyimide, polystyrene, cyclo-olefin polymer, cyclo-olefin copolymer, polydimethylsiloxane, parylene, low-loss plastic, polyethylene, polymethyl methacrylate, low-loss resin, low-loss glasses, low-loss ceramic, titanium dioxide, oil, air, nitrogen, helium, neon, argon, or combinations thereof. ### Claim 21 (depends on 16) The dynamic dispersion compensator of claim 16, wherein the backing layer of at least one of the plurality of stratified structures is a reflective metal or a frequency-selective surface. ### Claim 22 (depends on 21) The dynamic dispersion compensator of claim 21, wherein the reflective metal is selected from the group of aluminum, gold, silver, copper, titanium, nickel, cobalt, chromium, molybdenum, platinum, tungsten, or alloys of any of the foregoing. ### Claim 23 (depends on 16) The dynamic dispersion compensator of claim 16, wherein the dynamic dispersion compensator is configured to be dynamically tunable by at least: rotation of at least one stratified structure in the cohort, change of a thickness of at least one of the plurality of adjacent layers of at least one stratified structure in the cohort, or one or more combinations of any of the foregoing, wherein rotation of at least one stratified structure of the cohort changes an angle of incidence upon which the incident electromagnetic signal encounters any of the stratified structures within the cohort and thereby dynamically tunes the dynamic dispersion compensator by changing the group delay dispersion of the cohort, and wherein a change of a thickness of at least one of the plurality of adjacent layers of at least one stratified structure in the cohort thereby changes the group delay dispersion of the at least one stratified structure and thereby changes the group delay dispersion of the cohort. ### Claim 24 (depends on 16) The dynamic dispersion compensator of claim 16, wherein the incident electromagnetic signal has a carrier frequency between about 0.1 terahertz to about 10 terahertz. ### Claim 25 A method of compensating dispersion of an electromagnetic signal, comprising the steps of: receiving an incident electromagnetic signal by a dynamic dispersion compensator, wherein the dynamic dispersion compensator includes: a cohort of a plurality of stratified structures arranged relative to each other to communicate the incident electromagnetic signal, wherein the cohort defines a group delay dispersion of the cohort and the cohort is configured to introduce a group delay dispersion to the incident electromagnetic signal, wherein each stratified structure in the cohort includes a front portion and a back portion, and each stratified structure includes a plurality of adjacent layers, and each layer has a refractive index different from an immediately adjacent layer, and each stratified structure includes a backing layer at its back portion, wherein each stratified structure in the cohort defines a group delay dispersion for itself, and wherein the group delay dispersion of the cohort is dynamically tunable; and reflecting, by the dynamic dispersion compensator, a modified electromagnetic signal, wherein information carried by the modified electromagnetic signal corresponds to information carried by an initial electromagnetic signal absent experiencing dispersive effects. ### Claim 26 (depends on 25) The method of claim 25, wherein the cohort further includes at least one moveable reflective layer, and wherein the at least one moveable reflective layer of the cohort is configured to move from a first position to a second position where the second position blocks the front portion of at least one stratified structure in the cohort and thereby changes the group delay dispersion of the cohort. ### Claim 27 (depends on 25) The method of claim 25, further comprising the step of: dynamically tuning the dynamic dispersion compensator. ### Claim 28 (depends on 27) The method of claim 27, wherein the step of dynamically tuning the dynamic dispersion compensator includes: rotating at least one stratified structure of the cohort, positioning at least one moveable reflective layer on the front portion of at least one stratified structure in the cohort, changing a thickness of at least one of the plurality of adjacent layers of at least one of the stratified structures of the cohort, or one or more combinations of any of the foregoing, wherein rotating at least one stratified structure of the cohort changes an angle of incidence upon which the incident electromagnetic signal encounters any of the stratified structures within the cohort and thereby dynamically tunes the dynamic dispersion compensator by changing the group delay dispersion of the cohort, wherein positioning at least one moveable reflective layer on the front portion of at least one stratified structure in the cohort changes the group delay dispersion of the cohort and thereby dynamically tunes the dynamic dispersion compensator, and wherein changing a thickness of at least one of the plurality of adjacent layers of at least one of the stratified structures of the cohort changes the group delay dispersion of the at least one of the stratified structures of the cohort and thereby dynamically tunes the dynamic dispersion compensator. ### Claim 29 (depends on 25) The method of claim 25, wherein the plurality of adjacent layers of each of the plurality of stratified structures in the cohort are selected from one or more of: silicon, sapphire, quartz, polytetrafluoroethylene, polyimide, polystyrene, cyclo-olefin polymer, cyclo-olefin copolymer, polydimethylsiloxane, parylene, low-loss plastic, polyethylene, polymethyl methacrylate, low-loss resin, low-loss glasses, low-loss ceramic, titanium dioxide, oil, air, nitrogen, helium, neon, argon, or combinations thereof. ### Claim 30 (depends on 25) The dynamic dispersion compensator of claim 25, wherein the backing layer of at least one of the plurality of stratified structures is a reflective metal or a frequency-selective surface. ### Claim 31 (depends on 30) The dynamic dispersion compensator of claim 30, wherein the reflective metal is selected from the group of aluminum, gold, silver, copper, titanium, nickel, cobalt, chromium, molybdenum, platinum, tungsten, or alloys of any of the foregoing. ### Claim 32 (depends on 25) The dynamic dispersion compensator of claim 25, wherein the incident electromagnetic signal has a carrier frequency between about 0.1 terahertz to about 10 terahertz.