Frequency selective surface and method of manufacture

• US 20040119658A1
• Filed: 12/24/2002
• Published: 06/24/2004
• Est. Priority Date: 12/24/2002
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Intel Corporation
• Inventors: Waltho, Alan E.
• Granted Patent: US 6,995,733 B2
• Time in Patent Office: Days
• US Class Current: 343/909
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 15/0013 said selective devices working as frequency-selective reflecting surfaces, e.g. FSS, dichroic plates, surfaces being partly transmissive and reflective
• CPC Class Codes: H01Q 19/021 Means for reducing undesirable effects

Abstract

Briefly, in accordance with an embodiment of the invention, a frequency selective surface (FSS) structure and a method is provided. The FSS structure may include a first conductive plate over a first surface of a substrate. The FSS structure may further include a first printed inductor over the first surface of the substrate and coupled to the first conductive plate. The method may include forming a frequency selective surface by patterning a first conductive material over a surface of a substrate to form a printed inductor.

Claims

1. An apparatus, comprising:

a frequency selective surface (FSS) structure that includes;

a first conductive plate over a first surface of a substrate; and

a first printed inductor over the first surface of the substrate and coupled to the first conductive plate.

2. The apparatus of claim 1, wherein the FSS structure further includes;

a ground plane over a second surface of the substrate; and

a first conductive via in the substrate and coupled to the ground plane and the first printed inductor.

3. The apparatus of claim 2, wherein the ground plane, the first conductive plate, the first printed inductor, and the first conductive via form a resonant circuit.

4. The apparatus of claim 3, wherein the first conductive via is serially coupled to the printed inductor to form an inductive element.

5. The apparatus of claim 3, wherein the first conductive plate and the ground plane form a capacitive element, and wherein the first conductive plate forms an upper plate of the capacitive element and the ground plane forms a lower plate of the capacitive element.

6. The apparatus of claim 2, wherein the first printed inductor is coupled between the first conductive plate and the first conductive via.

7. The apparatus of claim 2, wherein the first printed inductor is a substantially rectangular-shaped conductor having a length at least as long as that of the first conductive via.

8. The apparatus of claim 2, wherein the length of the first conductive via is less than about 62 mils (about 1.57 mm) and wherein the length of the first printed inductor is greater than about 62 mils (about 1.57 mm).

11. The apparatus of claim 2, wherein the FSS structure further includes a second printed inductor over the second surface of the substrate and coupled between the first conductive via and the ground plane and wherein the second printed inductor is formed at a substantially right angle relative to the first printed inductor.

12. The apparatus of claim 2, wherein the FSS structure further includes:

a second conductive plate over the first surface of the substrate and separate from the first conductive plate;

a second printed inductor over the first surface of the substrate and coupled to the second conductive plate;

a second conductive via in the substrate and coupled to the ground plane and the second printed inductor.

13. The apparatus of claim 1, wherein the first conductive plate is substantially square-shaped.

14. The apparatus of claim 1, wherein the first printed inductor has a spiral shape.

15. The apparatus of claim 1, wherein the first printed inductor is a coil having at least one turn.

16. The apparatus of claim 1, further comprising an antenna adjacent to the FSS structure.

17. The apparatus of claim 1, wherein the first printed inductor and the first conductive plate are formed by patterning a single layer of conductive material.

18. An apparatus, comprising:

a first conductive plate on a first surface of a substrate;

a printed inductor on the first surface of the substrate and coupled to the first conductive plate;

a second conductive plate on a second surface of the substrate; and

a via between the first and second surfaces of the substrate and coupled to the printed inductor and the second conductive plate.

19. The apparatus of claim 18, wherein the printed inductor and the first conductive plate are formed by patterning a single layer of conductive material.

21. The apparatus of claim 18, wherein the substrate is a dielectric substrate.

22. The apparatus of claim 18, further comprising:

a second via between the first and second surfaces of the substrate;

a second patterned conductive material over the first surface of the substrate;

wherein the second patterned conductive material includes a second inductive element and a first plate of a second capacitive element coupled to the second inductive element;

wherein the second inductive element is coupled between the second via and the first plate of the second capacitive element; and

wherein the electrically conductive material forms the second plate of the second capacitive element.

20. An apparatus comprising:

a substrate;

a first patterned conductive material over a first surface of the substrate, wherein the first patterned conductive material includes a first inductive element and a first plate of a first capacitive element coupled to the first inductive element;

an electrically conductive material over a second surface of the substrate, wherein the electrically conductive material forms a second plate of the first capacitive element; and

a first via between the first and second surfaces of the substrate and coupled to the first inductive element and the conductive material.

23. A method, comprising:

forming a frequency selective surface by patterning a first conductive material over a surface of a substrate to form a printed inductor.

24. The method of claim 23, further comprising:

forming a via in the substrate; and

forming a conductive material within the via to form a conductive via coupled to the printed inductor.

25. The method of claim 24, further including pattering a second conductive material over a second surface of the substrate to form another printed inductor coupled to the conductive via.

26. The method of claim 23, wherein patterning includes patterning the first conductive material to form one plate of a capacitive element coupled to the printed inductor.

27. A system, comprising:

an antenna to communicate over a wireless local area network (WLAN); and

a frequency selective surface (FSS) structure coupled to the antenna, wherein the FSS includes;

a first conductive plate over a first surface of a substrate; and

a first printed inductor over the first surface of the substrate and coupled to the first conductive plate.

28. The system of claim 27, wherein the FSS further includes:

a ground plane over a second surface of the substrate; and

a first conductive via in the substrate and coupled to the ground plane and the first printed inductor.