Frequency selective high impedance surface
View Patent ↗Disclosed herein are various high-impedance surfaces having high capacitance and inductance properties. One exemplary high-impedance surface includes a plurality of conductive structures arranged in a lattice, wherein at least a subset of the conductive structures include a plurality of conductive plates arranged along a conductive post so that the conductive plates of one conductive structure interleave with one or more conductive plates of one or more adjacent conductive structure. Another exemplary high-impedance surface includes a plurality of conductive structures arranged in a lattice, where the conductive structures include one or more fractalized conductive plates having either indentions and/or projections that are coextensive with corresponding projections or indentations, respectively, of one or more adjacent conductive structures. Also disclosed are various exemplary implementations of such high-impedance surfaces.
1. A method comprising:
forming a first plurality of conductive structures at a surface of a conductor, each of the first plurality of conductive structures comprising:
a first post electrically coupled to and extending from the surface of the conductor;
a first plate electrically coupled to the first post at a first distance from the surface of the conductor; and
a second plate electrically coupled to the first post at a second distance from the surface of the conductor; and
forming a second plurality of conductive structures at the surface of the conductor, each of the second plurality of conductive structures comprising:
a second post electrically coupled to and extending from the surface of the conductor;
a third plate electrically coupled to the second post at a third distance from the surface of the conductor, the third distance being between the first and second distances;
wherein at least a portion of the third plate of one or more conductive structures of the second plurality of conductive structures overlaps a corresponding portion of at least one of the first or second plates of at least one adjacent conductive structure of the first plurality of conductive structures;
wherein the first plate of a first conductive structure of the first plurality of conductive structures comprises one or more indentations at a first edge;
wherein a second conductive structure of the second plurality of conductive structures comprises a fourth plate electrically coupled to the second post at the first distance from the surface of the conductor; and
wherein the fourth plate comprises one or more protrusions at a second edge, the one or more protrusions substantially coextensive with the respective one or more indentations of the first plate of the first conductive structure.
2. The method as in claim 1 , wherein forming the first and second pluralities of conductive structures comprises:
forming a first dielectric layer at the surface of the conductor;
forming a first plurality of vias extending through the first dielectric layer to the surface of the conductor;
disposing conductive material in the first plurality of holes to form first portions of the first posts of the first plurality of conductive structures;
forming a first conductive layer overlaying the first dielectric layer;
removing portions of the first conductive layer, the remaining portions of the first conductive layer comprising the first plates of the first plurality of conductive structures;
forming a second dielectric layer overlaying the first dielectric layer and the remaining portions of the first conductive layer,
forming a second plurality of vias extending through the first and second dielectric layers to the surface of the conductor;
disposing conductive material in the second plurality of holes to form at least a portion of the second posts of the second plurality of conductive structures;
forming a second conductive layer overlaying the second dielectric layer;
removing portions of the second conductive layer, the remaining portions of the second conductive layer comprising the third plates of the second plurality of conductive structures;
forming a third dielectric layer overlaying the second dielectric layer and the remaining portions of the second conductive layer;
forming a third plurality of vias extending through the second and third dielectric layers;
disposing conductive material in the third plurality of holes to form second portions of the first posts of the first plurality of conductive structures;
forming a third conductive layer overlaying the third dielectric layer; and
removing portions of the third conductive layer, the remaining portions of the third conductive layer comprising the second plates of the first plurality of conductive structures.
3. The method as in claim 1 , wherein:
forming each of the first plurality of conductive structures comprises:
attaching the first plate to the first post at a first position on the first post;
attaching the second plate to the first post at a second position on the first post; and
attaching an end of the first post to the surface of the conductor; and
forming each of the second plurality of conductive structures comprises:
attaching the third plate to the second post at a third position on the second post; and
attaching an end of the second post to the surface of the conductor.
4. The method as in claim 1 , wherein forming the first and second pluralities of conductive structures comprises:
forming a plurality of ceramic layers, each ceramic layer including corresponding metallizations for the portions of the first and second pluralities of conductive structures at the ceramic layer; and
adhering the plurality of ceramic layers together.
5. The method as in claim 4 , wherein adhering the plurality of ceramic layers together includes applying heat to the ceramic layers.
6. An apparatus comprising:
a conductor; and
a plurality of conductive structures disposed at the conductor, each of the plurality of conductive structures comprising:
a post electrically coupled to and extending from a surface of the conductor; and
two or more plates electrically coupled to the post at respective distances from the surface of the conductor;
wherein at least a portion of at least one of the two or more plates overlaps a corresponding portion of at least one of the two or more plates of at least one adjacent conductive structure;
wherein a first plate of the two or more plates of a first conductive structure of the plurality of conductive structures comprises one or more indentations at a first edge of the first plate; and
wherein a second plate of the two or more plates of a second conductive structure of the plurality of conductive structures comprises one or more protrusions at a second edge of the second plate, the one or more protrusions substantially coextensive with the respective one or more indentations of the first plate of the first conductive structure.
7. The apparatus as in claim 6 , wherein at least one of the two or more plates of one or more of the plurality of conductive structures comprises conductive material arranged in a substantially spiral pattern.
8. The apparatus as in claim 6 , further comprising at least one conductive device adjacent to the plurality of conductive structures.
9. The apparatus as in claim 8 , wherein an operating frequency of the at least one conductive device is within a stop band frequency range of the high-impedance surface.
10. The apparatus as in claim 8 , wherein the at least one conductive device includes one or more of an inductor, an antenna, a microstrip transmission line or differential pair transmission lines.
11. An apparatus comprising:
a conductor; and
a plurality of conductive structures disposed at the conductor, each of the plurality of conductive structures comprising:
a post electrically coupled to and extending from a surface of the conductor; and
a first plate electrically coupled to the post at a first distance from the surface of the conductor;
wherein the first plate of a first conductive structure of the plurality of conductive structures comprises one or more indentations along a first edge;
wherein the first plate of a second conductive structure of the plurality of conductive structures comprises one or more protrusions along a second edge adjacent to the first edge of the first plate, the one or more protrusions substantially coextensive with the respective one or more indentations of the first edge of the first plate of the first conductive structure; and
wherein the first plate of one or more of the plurality of conductive structures comprises conductive material arranged in a substantially spiral pattern.
12. The apparatus as in claim 11 , wherein:
at least a first conductive structure of the plurality of conductive structures further comprises a second plate electrically coupled to the post, the second plate being a second distance from the surface of the conductor; and
at least a portion of a first plate of at least a second conductive structure adjacent to the first conductive structure overlaps a corresponding portion of at least one of the first or second plates of the first conductive structure.
13. The apparatus as in claim 11 , further comprising at least one conductive device adjacent to the plurality of conductive structures.
14. The apparatus as in claim 13 , wherein an operating frequency of the at least one conductive device is within a stop band frequency range of the high-impedance surface.
15. The apparatus as in claim 13 , wherein the at least one conductive device includes one or more of an inductor, an antenna, a microstrip transmission line or differential pair transmission lines.
16. A method comprising:
forming a plurality of conductive structures at a surface of a conductor, each of the plurality of conductive structures comprising:
a post electrically coupled to and extending from the surface of the conductor; and
a first plate electrically coupled to the post; and
wherein the first plate of one or more of the plurality of conductive structures comprises conductive material arranged in a substantially spiral pattern, the first plate of a first conductive structure of the plurality of conductive structures comprises one or more indentations at a first edge, and the first plate of a second conductive structure of the plurality of conductive structures comprises one or more protrusions at a second edge, the one or more protrusions substantially coextensive with the respective one or more indentations of the first plate of the first conductive structure.
17. The method as in claim 16 , wherein forming the plurality of conductive structures includes:
forming a dielectric layer at the surface of the conductor;
forming a plurality of vias extending through the dielectric layer to the surface of the conductor;
disposing conductive material in the plurality of vias to form the plurality of posts;
forming a conductive layer overlaying the dielectric layer; and
removing portions of the conductive layer, the remaining portions of the conductive layer comprising the first plates of the plurality of conductive structures.
18. The method as in claim 16 , wherein forming the plurality of conductive structures comprises:
forming a plurality of ceramic layers, each ceramic layer including corresponding metallizations for the portions of the plurality of conductive structures at the ceramic layer; and
adhering the plurality of ceramic layers together.
19. The method as in claim 18 , wherein adhering the plurality of ceramic layers together includes applying heat to the ceramic layers.
20. An apparatus comprising:
a conductor; and
a plurality of conductive structures disposed at the conductor, each of the plurality of conductive structures comprising:
a post electrically coupled to and extending from a surface of the conductor; and
two or more plates electrically coupled to the post at respective distances from the surface of the conductor;
wherein a first plate of the two or more plates of a first conductive structure of the plurality of conductive structures comprises one or more indentations along a first edge;
wherein a second plate of the two or more plates of a second conductive structure of the plurality of conductive structures comprises one or more protrusions along a second edge adjacent to the first edge of the first plate, the one or more protrusions; and
wherein at least one of the two or more plates of one or more of the plurality of conductive structures comprises conductive material arranged in a substantially spiral pattern.
21. The apparatus as in claim 20 , wherein at least a portion of at least one of the two or more plates of at least a first conductive structure of the plurality of conductive structures overlaps a corresponding portion of at least one of the two or more plates of at least one adjacent conductive structure.
22. The apparatus as in claim 20 , further comprising at least one conductive device adjacent to the plurality of conductive structures.
23. The apparatus as in claim 22 , wherein an operating frequency of the at least one conductive device is within a stop band frequency range of the high-impedance surface.
24. The apparatus as in claim 22 , wherein the at least one conductive device includes one or more of an inductor, an antenna, a micro strip transmission line or differential pair transmission lines.
25. An apparatus comprising:
a conductor;
a first conductive structure disposed at the conductor, the first conductive structure comprising:
a first post electrically coupled to and extending from a surface of the conductor; and
a first plate electrically coupled to the first post and comprising one or more indentations along a first edge; and
a second conductive structure disposed adjacent to the first conductive structure at the conductor, the second conductive structure comprising:
a second post electrically coupled to and extending from the surface of the conductor, and
a second plate electrically coupled to the second post and comprising one or more protrusions along a second edge adjacent to the first edge of the first plate;
wherein the one or more protrusions of the second edge of the second plate are substantially coextensive with the respective one or more indentations of the first edge of the first plate.
26. The apparatus as in claim 25 , wherein:
the first conductive structure further comprises a third plate electrically coupled to the first post, the third plate comprising one or more protrusions along a third edge of the third plate;
the second conductive structure further comprises a fourth plate electrically coupled to the second post, the fourth plate comprising one or more indentations along a fourth edge adjacent to the third edge; and
the one or more protrusions of the third edge of the third plate are substantially coextensive with the respective one or more indentations of the fourth edge of the fourth plate.
27. The apparatus as in claim 25 , wherein at least one of the first or second plates comprises a conductive material arranged in a substantially spiral pattern.
28. The apparatus as in claim 25 , further comprising at least one conductive device adjacent at least one of the first and second conductive structures.
29. The apparatus as in claim 28 , wherein an operating frequency of the at least one conductive device is within a stop band frequency range of the high-impedance surface.
30. The apparatus as in claim 28 , wherein the at least one conductive device includes one or more of an inductor, an antenna, a microstrip transmission line or differential pair transmission lines.
31. A method comprising:
forming a first conductive structure disposed at a surface of a conductor, the first conductive structure comprising:
a first post electrically coupled to and extending from the surface of the conductor; and
a first plate electrically coupled to the first post and comprising one or more indentations along a first edge; and
forming a second conductive structure adjacent to the first conductive structure at the surface of the conductor, the second conductive structure comprising:
a second post electrically coupled to and extending from the surface of the conductor; and
a second plate electrically coupled to the second post and comprising one or more protrusions along a second edge adjacent to the first edge of the first plate;
wherein the one or more protrusions of the second edge of the second plate are substantially coextensive with the respective one or more indentations of the first edge of the first plate.
32. The method as in claim 31 , wherein forming the first and conductive structures comprises:
forming a dielectric layer at the surface of the conductor;
forming first and second vias extending through the dielectric layer to the surface of the conductor;
disposing conductive material in the first and second vias to Loin the first and second posts;
forming a conductive layer overlaying the dielectric layer; and
removing portions of the conductive layer, the remaining portions of the conductive layer comprising the first and second plates.
33. The method as in claim 31 , wherein forming the first and second conductive structures comprises:
forming a plurality of ceramic layers, each ceramic layer including corresponding metallizations for the portions of the first and second conductive structures at the ceramic layer; and
adhering the plurality of ceramic layers together.
34. The method as in claim 33 , wherein adhering the plurality of ceramic layers together includes applying heat to the ceramic layers.
35. An apparatus comprising:
a conductor;
a first set of conductive structures disposed at the conductor, each of the first set of conductive structures comprising:
a first post electrically coupled to and extending from a surface of the conductor; and
a first plate electrically coupled to the first post and comprising one or more indentations along one or more edges; and
a second set of conductive structures disposed between and adjacent to the first set of conductive structures at the conductor, each of the second set of conductive structures comprising:
a second post electrically coupled to and extending from the surface of the conductor; and
a second plate electrically coupled to the second post and comprising one or more protrusions along one or more edges;
wherein the one or more protrusions of the second plates of the second set of conductive structures are substantially coextensive with the respective one or more indentations of the first plates of one or more adjacent conductive structures of the first set of conductive structures.
36. The apparatus as in claim 35 , wherein at least one of the first plate or second plate comprises conductive material arranged in a substantially spiral pattern.
37. The apparatus as in claim 35 , further comprising at least one conductive device adjacent to the plurality of conductive structures.
38. The apparatus as in claim 37 , wherein an operating frequency of the at least one conductive device is within a stop band frequency range of the high-impedance surface.
39. The apparatus as in claim 37 , wherein the at least one conductive device includes one or more of an inductor, an antenna, a microstrip transmission line or differential pair transmission lines.