Electromagnetic coupler circuit board having at least one angled conductive trace

• US 6,611,181 B2
• Filed: 03/01/2001
• Issued: 08/26/2003
• Est. Priority Date: 11/15/2000
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Benham, John R., Amirtharajah, Rajeevan, Knight, Thomas F. Jr., Marketkar, Nandu J.
• Primary Examiner(s): Lee, Benny
• Application Number:
  US09/797,631
• Publication Number:
  US 20020057136A1
• Time in Patent Office: 908 Days
• Field of Search: 333/22.R, 333/24.R, 333/111, 333/116, 333/109
• US Class Current: 333/24.00R
• CPC Class Codes: H01P 5/185 Edge coupled lines
• CPC Class Codes: H01P 5/187 Broadside coupled lines
• CPC Class Codes: H05K 1/0228 Compensation of cross-talk by a mutually correlated lay-out of printed circuit traces, e.g. for compensation of cross-talk in mounted connectors balanced signal pairs H05K1/0245
• CPC Class Codes: H05K 1/0237 High frequency adaptations H05K1/0216 takes precedence
• CPC Class Codes: H05K 1/0239 Signal transmission by AC coupling
• CPC Class Codes: H05K 1/0245 Lay-out of balanced signal pairs, e.g. differential lines or twisted lines
• CPC Class Codes: H05K 1/14 Structural association of two or more printed circuits providing electric connection to or between printed circuits H05K1/11, H01R12/00
• CPC Class Codes: H05K 2201/09263 Meander
• CPC Class Codes: H05K 2201/097 Alternating conductors, e.g. alternating different shaped pads, twisted pairs; Alternating components

Abstract

An electromagnetic (EM) coupler including a first transmission structure having a first geometry, and a second transmission structure having a second geometry and forming an EM coupler with the first transmission structure, the first and second geometries being selected to reduce sensitivity of EM coupling to relative positions of the first and second transmission structures is disclosed.

Claims

1. A method, comprising:

depositing a conductive trace on a circuit board, the conductive trace including a first transmission structure having a plurality of transmission sections, each transmission section having an angle of deflection relative to an axis parallel to the first transmission structure,

the angle of deflection being such that, when the first transmission structure is positioned proximate to a second transmission structure to form an electromagnetic coupler, a total capacitance between the first and second transmission structures is maintained relatively constant over a range of relative positions of the first and second transmission structures,

wherein the first transmission structure includes a zig-zag geometry and the second transmission structure includes a straight geometry, and wherein the first transmission structure dielectrically crosses the second transmission structure at multiple locations due to the angle of deflection.

2. The method of claim 1, further comprising forming a planar conductive reference plane parallel to a plane containing the first transmission structure, the planar conductive reference plane providing a reference potential to the first transmission structure.

3. The method of claim 1, wherein the first transmission structure is able to transfer signals in an electronic system.

4. The method of claim 3, wherein the electronic system is a member selected from the group consisting of:

a computer system;

a computer bus;

a computer motherboard;

a daughter card;

a multi-chip module;

an integrated circuit;

a flex circuit;

a printed circuit board; and

a cable circuit.

5. The method of claim 1, further comprising:

forming a fringe capacitance and a parallel plane capacitance between the first and second transmission structures when the first and second transmission structures are positioned proximate to each other via the angle of deflection; and

maintaining the total capacitance relatively constant over the range of relative positions of the first and second transmission structures via a combination of the fringe capacitance and the parallel plane capacitance.

6. The method of claim 1, wherein the angle of deflection is an other than 90°

angle.

7. A method, comprising:

depositing a conductive trace on a circuit board, the conductive trace including a first transmission structure having a plurality of transmission sections, each transmission section having an angle of deflection relative to an axis parallel to the first transmission structure,

the angle of deflection being such that, when the first transmission structure is positioned proximate to a second transmission structure to form an electromagnetic coupler, a total capacitance between the first and second transmission structures is maintained relatively constant over a range of relative positions of the first and second transmission structures,

wherein the first transmission structure comprises at least one differential pair of conductors parallel to each other.

8. The method of claim 7, wherein the angle of deflection is an other than 90°

angle.

9. The method of claim 7, further comprising:

forming a fringe capacitance and a parallel plane capacitance between the first and second transmission structures when the first and second transmission structures are positioned proximate to each other via the angle of deflection; and

maintaining the total capacitance relatively constant over the range of relative positions of the first and second transmission structures via a combination of the fringe capacitance and the parallel plane capacitance.

10. An apparatus, comprising:

a circuit board; and

a conductive trace disposed on the circuit board, the conductive trace including a first transmission structure having a plurality of transmission sections, each transmission section having an angle of deflection relative to an axis parallel to the first transmission structure,

wherein the angle is selected such that, when the first transmission structure is positioned proximate to a second transmission structure to form an electromagnetic coupler, a total capacitance between the first and second transmission structures is maintained relatively constant over a range of relative positions of the first and second transmission structures.

wherein the first transmission structure comprises at least one differential pair of conductors parallel to each other.

11. The apparatus of claim 10, wherein the angle of deflection forms a fringe capacitance and a parallel plane capacitance between the first and second transmission structures when the first and second transmission structures are positioned proximate to each other, and wherein the fringe capacitance and the parallel plane capacitance, in combination, maintain the total capacitance relatively constant over the range of relative positions of the first and second transmission structures.

12. The apparatus of claim 10, wherein the angle of deflection is an other than 90°

angle.

13. The apparatus of claim 10, further comprising a planar conductive reference plane parallel to a plane containing the first transmission structure, the planar conductive reference plane providing a reference potential to the first transmission structure.

14. The apparatus of claim 10, wherein the first transmission structure is able to transfer signals in an electronic system.

15. The apparatus of claim 14, wherein the electronic system is a member selected from the group consisting of:

a computer system;

a computer bus;

a computer motherboard;

a daughter card;

a multi-chip module;

an integrated circuit;

a flex circuit;

a printed circuit board; and

a cable circuit.

16. An apparatus, comprising:

a circuit board; and

a conductive trace disposed on the circuit board, the conductive trace including a first transmission structure having a plurality of transmission sections, each transmission section having an angle of deflection relative to an axis parallel to the first transmission structure,

wherein the angle is selected such that, when the first transmission structure is positioned proximate to a second transmission structure to form an electromagnetic coupler, a total capacitance between the first and second transmission structures is maintained relatively constant over a range of relative positions of the first and second transmission structures,

wherein the first transmission structure includes a zig-zag geometry and the second transmission structure includes a straight geometry, and wherein the first transmission structure dielectrically crosses the second transmission structure at multiple locations due to the angle of deflection.

17. The apparatus of claim 16, wherein the angle of deflection is an other than 90°

angle.

18. The apparatus of claim 16, wherein the angle of deflection forms a fringe capacitance and a parallel plane capacitance between the first and second transmission structures when the first and second transmission structures are positioned proximate to each other, and wherein the fringe capacitance and the parallel plane capacitance, in combination, maintain the total capacitance relatively constant over the range of relative positions of the first and second transmission structures.