System and method for improving performance of coplanar waveguide bends at mm-wave frequencies

• US 7,990,237 B2
• Filed: 01/16/2009
• Issued: 08/02/2011
• Est. Priority Date: 01/16/2009
• Status: Expired due to Fees

• Current Assignee: Toyota Motor Corporation
• Original Assignee: Toyota Motor Engineering & Manufacturing North America Incorporated (Toyota Motor Corporation)
• Inventors: Rida, Amin, Margomenos, Alexandros
• Primary Examiner(s): LEE, BENNY T
• Application Number:
  US12/355,526
• Publication Number:
  US 20100182107A1
• Time in Patent Office: 928 Days
• Field of Search: 333/246, 333/33, 333/34
• US Class Current: 333/246
• CPC Class Codes: H01P 11/003 Manufacturing lines with conductors on a substrate, e.g. strip lines, slot lines
• CPC Class Codes: H01P 3/026 Coplanar striplines [CPS]
• CPC Class Codes: H01Q 13/206 Microstrip transmission line antennas
• CPC Class Codes: H05K 1/0219 Printed shielding conductors for shielding around or between signal conductors, e.g. coplanar or coaxial printed shielding conductors
• CPC Class Codes: H05K 1/025 Impedance arrangements, e.g. impedance matching, reduction of parasitic impedance H05K1/024 and H05K1/0243 take precedence; for semiconductor devices H01L23/66
• CPC Class Codes: H05K 2201/0141 Liquid crystal polymer [LCP]
• CPC Class Codes: H05K 2201/09272 Layout details of angles or corners
• CPC Class Codes: H05K 2201/09618 Via fence, i.e. one-dimensional array of vias

Abstract

An apparatus including a liquid crystal polymer substrate having a top surface and a bottom surface, a coplanar waveguide formed on the top surface of the liquid crystal polymer substrate, the coplanar waveguide having a 90 degree bend with a mitered edge, an inner via positioned adjacent to an inner corner of the 90 degree bend, and an outer via positioned adjacent to the mitered edge of the 90 degree bend, the inner and outer vias positioned along a first plane that is perpendicular to a second plane defined by the mitered edge.

Claims

1. An apparatus comprising:

a substrate having a top surface and a bottom surface;

a waveguide disposed on the top surface of the substrate, the waveguide having a pair of coplanar ground planes and a signal plane positioned between the pair of coplanar ground planes, the pair of coplanar ground planes co-extending with the signal plane, the waveguide defining a 90 degree bend with an inner edge and a chamfered outer edge; and

an inner via being positioned in one of the pair of coplanar ground planes adjacent to the inner edge of the 90 degree bend.

2. The apparatus of claim 1 wherein the substrate is a liquid crystal polymer substrate.

3. The apparatus of claim 1 wherein the inner via is positioned about 0.15 millimeters away from the inner edge.

4. The apparatus of claim 1 further comprising an outer via positioned in the other one of the pair of coplanar ground planes adjacent to the chamfered outer edge of the 90 degree bend.

5. The apparatus of claim 4 wherein the inner edge, the chamfered outer edge, the inner via and the outer via are all positioned along a first plane.

6. The apparatus of claim 4 wherein the inner and outer vias are positioned along a first plane that is perpendicular to a second plane defined by the chamfered outer edge.

7. The apparatus of claim 4 wherein the outer via is positioned about 0.15 millimeters away from the chamfered outer edge.

8. The apparatus of claim 4 wherein the inner and outer vias are filled with a metal material.

9. The apparatus of claim 4 wherein the inner and outer vias each have a diameter of about 0.15 millimeters.

10. An apparatus comprising:

a liquid crystal polymer substrate having a top surface and a bottom surface;

a coplanar waveguide disposed on the top surface of the liquid crystal polymer substrate, the coplanar waveguide having a pair of coplanar ground planes and a signal plane positioned between the pair of coplanar ground planes, the pair of coplanar ground planes co-extending with the signal plane, the coplanar waveguide defining a 90 degree bend with a mitered edge;

an inner via positioned in one of the pair of coplanar ground planes adjacent to an inner corner of the 90 degree bend; and

an outer via positioned in the other one of the pair of coplanar ground planes adjacent to the mitered edge of the 90 degree bend, the inner and outer vias being positioned along a first plane that is perpendicular to a second plane defined by the mitered edge.

11. The apparatus of claim 10 wherein the inner corner, the mitered edge, the inner via and the outer via are all positioned along a first plane.

12. The apparatus of claim 10 wherein the inner via is positioned about 0.15 millimeters away from the inner corner.

13. The apparatus of claim 10 wherein the outer via is positioned about 0.15 millimeters away from the mitered edge.

14. The apparatus of claim 10 wherein the inner and outer vias are filled with a metal material.

15. The apparatus of claim 10 wherein the inner and outer vias each have a diameter of about 0.15 millimeters.

16. An apparatus comprising:

a liquid crystal polymer substrate having a top surface and a bottom surface;

a coplanar waveguide disposed on the top surface of the liquid crystal polymer substrate, the coplanar waveguide having a pair of coplanar ground planes and a signal plane positioned between the pair of coplanar ground planes, the pair of coplanar ground planes co-extending with the signal plane, the coplanar waveguide defining a 90 degree bend with an inner edge and a chamfered outer edge;

an inner via positioned in one of the pair of coplanar ground planes adjacent to the inner edge of the 90 degree bend; and

an outer via positioned in the other one of the pair of coplanar ground planes adjacent to the chamfered outer edge of the 90 degree bend, the inner and outer vias being positioned along a first plane that is perpendicular to a second plane defined by the chamfered outer edge.

17. The apparatus of claim 16 wherein the inner edge, the chamfered outer edge, the inner via and the outer via are all positioned along a first plane.

18. The apparatus of claim 16 wherein the inner via is positioned about 0.15 millimeters away from the inner edge.

19. The apparatus of claim 16 wherein the outer via is positioned about 0.15 millimeters away from the chamfered outer edge.