Waveguide structure and printed-circuit board

• US 9,634,370 B2
• Filed: 06/24/2014
• Issued: 04/25/2017
• Est. Priority Date: 06/24/2008
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Toyao, Hiroshi
• Primary Examiner(s): Pascal, Robert
• Assistant Examiner(s): Glenn, Kimberly
• Application Number:
  US14/312,971
• Publication Number:
  US 20140300429A1
• Time in Patent Office: 1,036 Days
• Field of Search: 333204, 333205, 333219, 333235, 343909, 343700 MS
• CPC Class Codes: H01P 1/2005 Electromagnetic photonic bandgaps [EPB], or photonic bandgaps [PBG]
• CPC Class Codes: H01P 1/2013 Coplanar line filters
• CPC Class Codes: H01P 3/006 Conductor backed coplanar waveguides
• CPC Class Codes: H01P 3/026 Coplanar striplines [CPS]
• CPC Class Codes: H01P 3/081 Microstriplines
• CPC Class Codes: H01P 5/028 between strip lines
• CPC Class Codes: H01P 7/082 Microstripline resonators H01P7/088 takes precedence
• CPC Class Codes: H01Q 9/04 Resonant antennas
• CPC Class Codes: H05K 1/0236 Electromagnetic band-gap structures
• CPC Class Codes: H05K 1/165 incorporating printed inductors
• CPC Class Codes: H05K 2201/09236 Parallel layout layout of balanced signal pairs H05K1/0245; superposed layout H05K2201/09672
• CPC Class Codes: H05K 2201/09263 Meander
• CPC Class Codes: H05K 2201/09309 Core having two or more power planes; Capacitive laminate of two power planes
• CPC Class Codes: H05K 3/4602 characterized by a special circuit board as base or central core whereon additional circuit layers are built or additional circuit boards are laminated

Abstract

A waveguide structure or a printed-circuit board is formed using a plurality of unit structures which are repetitively aligned in a one-dimensional manner or in a two-dimensional manner. The unit structure includes first and second conductive planes which are disposed in parallel with each other, a transmission line having an open end which is formed in a layer different from the first and second conductive planes and positioned to face the second conductive plane, and a conductive via electrically connecting the transmission line to the first conductive plane.

Claims

1. A waveguide structure, comprising:

a first conductive plane formed as a predetermined area;

a second conductive plane formed in parallel with the first conductive plane; and

a plurality of unit structures, each of which includes;

a transmission line having a first end serving as an open end and a second end, the transmission line having a thin and elongated shape being formed in a different layer than the first conductive plane and the second conductive plane and being positioned relatively close to the second conductive plane; and

a conductive via electrically connecting the second end of the transmission line to the first conductive plane,

wherein the unit structures are repetitively aligned in a one-dimensional manner or in a two-dimensional manner over the predetermined area, and

wherein a distance between the transmission line and the second conductive plane is smaller than a distance between the transmission line and the first conductive plane.

2. The waveguide structure according to claim 1, the transmission line having a straight, curved, or polygonal shape that is coupled with the conductive via, thereby forming a microstrip line that uses the second conductive plane as a return path.

3. The waveguide structure according to claim 2, wherein at least a majority of a plurality of the transmission lines included in the plurality of unit structures have a straight-linear shape which is elongated in a plan view and inclined to a reference line connecting between a plurality of conductive vias included in the plurality of unit structures, which are positioned adjacent to each other, at a prescribed angle.

4. The waveguide structure according to claim 2, wherein substantially all of the unit structures each comprises a transmission line having the thin-and-elongated shape with a single portion, as configured to be oriented in a common single direction.

5. The waveguide structure according to claim 4, as configured so that a length of the thin shape serves as a design parameter for controlling a band gap of the waveguide structure without changing an area of the thin shape.

6. The waveguide structure according to claim 1, wherein the transmission line is positioned to face the second conductive plane outside a region interposed between the first and second conductive planes, and wherein a clearance is formed at a prescribed position proximate to the conductive via in the second conductive plane, thus electrically isolating the second conductive plane from the conductive via.

7. The waveguide structure according to claim 6, wherein the transmission line is covered with a dielectric layer.

8. The waveguide structure according to claim 1, wherein the transmission line is formed inside a region circumscribed between the first conductive plane and the second conductive plane.

9. The waveguide structure according to claim 1, wherein the transmission line comprises a first transmission line located inside a region circumscribed between the first conductive plane and the second conductive plane, and wherein the conductive via comprises a first conductive via, the waveguide structure further comprising:

a second transmission line having an open end laid on a second plane, which is positioned to face the second conductive plane outside the region circumscribed between the first and second conductive planes; and

a second conductive via electrically connecting the first transmission line to the second transmission line,

wherein a clearance is formed at a prescribed position corresponding to the second conductive via in the second conductive plane, which is thus electrically isolated from the second conductive via.

10. The waveguide structure according to claim 9, wherein each of the first transmission line coupled with the first conductive via and the second transmission line coupled with the second conductive via forms a microstrip line using the second conductive plane as a return path, and wherein each transmission line has one open end and the other end connected to its conductive via.

11. The waveguide structure according to claim 1, wherein the transmission line comprises a first transmission line located inside a region circumscribed between the first conductive plane and the second conductive plane, and wherein the conductive via comprises a first conductive via, the waveguide structure further comprising:

a second transmission line having an open end laid on a second plane, which is positioned to face the second conductive plane inside the region circumscribed between the first and second conductive planes; and

a second conductive via electrically connecting the second transmission line to the second conductive plane.

12. The waveguide structure according to claim 1, wherein the transmission line included in at least one of the plurality of unit structures has a spiral shape in which the first end of the transmission line is spirally wound about the second end of the transmission line positionally matching the conductive via in a plan view.

13. The waveguide structure according to claim 1, wherein the transmission line included in at least one of the plurality of units structures has a meandering shape in which the first end of the transmission line is meandered from the second end of the transmission line positionally matching the conductive via in a plan view.

14. The waveguide structure according to claim 1, as comprising an electromagnetic band-gap (EBG) structure designed to suppress electromagnetic waves from propagating in a specific frequency band.

15. The waveguide structure according to claim 1, as implemented on a printed-circuit board.

16. The waveguide structure according to claim 15, wherein the waveguide structure on the printed-circuit board comprises a first waveguide structure in a first predetermined area on the printed-circuit board, and wherein the printed-circuit board further includes a second waveguide structure in a second predetermined area of the printed-circuit board, the first and second waveguide structures configured to have two different band gaps.

17. The waveguide structure according to claim 1, wherein the transmission line is disposed outside a first dielectric layer formed between the first conductive plane and the second conductive plane, wherein a second dielectric layer and wherein a thickness of the second dielectric layer is smaller than a thickness of the first dielectric layer.