Hollow-waveguide-to-planar-waveguide transition including a coupling conductor having one or more conductors branching therefrom

• US 10,811,753 B2
• Filed: 07/05/2016
• Issued: 10/20/2020
• Est. Priority Date: 07/05/2016
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Nakajima, Hiromasa, Hirota, Akimichi, Yoneda, Naofumi, Oshima, Takeshi
• Primary Examiner(s): Lee, Benny T
• Application Number:
  US16/098,062
• Publication Number:
  US 20190148808A1
• Time in Patent Office: 1,568 Days
• Field of Search: 333 26
• CPC Class Codes: H01P 1/02 Bends; Corners; Twists
• CPC Class Codes: H01P 3/081 Microstriplines
• CPC Class Codes: H01P 3/121 integrated in a substrate
• CPC Class Codes: H01P 5/08 for linking dissimilar lines or devices H01P1/16, H01P5/04 take precedence; linking lines of the same kind but with different dimensions H01P5/02
• CPC Class Codes: H01P 5/107 Hollow-waveguide/strip-line transitions

Abstract

A hollow-waveguide-to-planar-waveguide transition circuit includes: a dielectric substrate; strip conductors formed on a first main surface of the dielectric substrate; a ground conductor formed on a second main surface of the dielectric substrate, facing the strip conductors in the thickness direction; a slot formed in the ground conductor; a coupling conductor formed at a position to be electrically coupled with the strip conductors on the first main surface; and branch conductor lines formed on the first main surface. Each of the branch conductor lines includes a base portion branching from the coupling conductor and a tip portion that is electrically open.

Claims

1. A hollow-waveguide-to-planar-waveguide transition circuit for transmitting a high-frequency signal, the hollow-waveguide-to-planar-waveguide transition circuit comprising:

a dielectric substrate having a first main surface and a second main surface which face each other in a thickness direction of the dielectric substrate;

one or more strip conductors formed on the first main surface, extending along a first in-plane direction determined in advance;

a ground conductor formed on the second main surface to face the one or more strip conductors in the thickness direction;

one or more slots formed in the ground conductor and extending in a second in-plane direction different from the first in-plane direction on the second main surface;

a coupling conductor formed at a position to be electrically coupled with the one or more strip conductors on the first main surface, and disposed at a position facing the one or more slots in the thickness direction; and

one or more branch conductor lines branching from an end portion of the coupling conductor in the second in-plane direction on the first main surface, each of the branch conductor lines having a respective base portion branching from the coupling conductor and having a corresponding tip portion that is electrically open,

wherein no conductor is provided to connect any of the one or more strip conductors, the coupling conductor, and the one or more branch conductor lines on the first main surface to the ground conductor on the second main surface.

2. The hollow-waveguide-to-planar-waveguide transition circuit according to claim 1, wherein a respective length of each of the one or more branch conductor lines extending from the respective base portion to the corresponding tip portion is equal to a quarter of a wavelength corresponding to a center frequency of a predetermined frequency band for use in the high-frequency signal.

3. The hollow-waveguide-to-planar-waveguide transition circuit according to claim 2, wherein the respective base portion of each of the one or more branch conductor lines is equivalently in an electrical short-circuit state with respect to the center frequency.

4. The hollow-waveguide-to-planar-waveguide transition circuit according to claim 2, wherein a respective width of each of the one or more branch conductor lines is equal to or less than one-tenth of the wavelength.

5. The hollow-waveguide-to-planar-waveguide transition circuit according to claim 1, wherein the one or more branch conductor lines include branch conductor lines that are arranged on the couplings conductor around peripheries at opposite ends of each of the one or more slots in the second-in-place direction of said each of the one or more slots as viewed from the thickness direction.

6. The hollow-waveguide-to-planar-waveguide transition circuit according to claim 1, wherein at least one of the one or more branch conductor lines has a bent shape.

7. The hollow-waveguide-to-planar-waveguide transition circuit according to claim 1, wherein the coupling conductor includes:

a main coupling portion connected to the one or more strip conductors; and

a coupling end portion connected to the respective base portion of each of the one or more branch conductor lines, wherein

a width of the coupling end portion in the first in-plane direction is narrower than a width of the main coupling portion in the first in-plane direction.

8. The hollow-waveguide-to-planar-waveguide transition circuit according to claim 7, wherein the coupling end portion includes a notched portion to form the width of the coupling end portion.

9. The hollow-waveguide-to-planar-waveguide transition circuit according to claim 8, wherein the coupling conductor has a stair shape in which a width of the main coupling portion extending in the first in-plane direction changes in a tapered manner that stepwise increases the width of the main coupling portion as a location of the width of the coupling conductor extending in the first in-plane direction changes from the coupling end portion toward the one or more strip conductors.

10. The hollow-waveguide-to-planar-waveguide transition circuit according to claim 8, wherein the coupling conductor has a tapered shape in which a width of the main coupling portion extending in the first in-plane direction changes in a manner that increases the width of the main coupling conductor as a location of the width of the coupling conductor extending in the first in-plane direction changes from the coupling end portion toward the one or more strip conductors.

11. The hollow-waveguide-to-planar-waveguide transition circuit according to claim 1, further comprising a hollow waveguide having one end portion connected to a region containing the one or more slots in the ground conductor.

12. The hollow-waveguide-to-planar-waveguide transition circuit according to claim 11, wherein a guide-axis direction of the hollow waveguide and the second main surface are orthogonal to each other.

13. The hollow-waveguide-to-planar-waveguide transition circuit according to claim 1, wherein the coupling conductor is physically connected to the one or more strip conductors.

14. The hollow-waveguide-to-planar-waveguide transition circuit according to claim 1, wherein each of the one or more slots have respective end portions that have corresponding widths which are larger than a width of a corresponding midportion of said each of the one or more slots.

15. A hollow-waveguide-to-planar-waveguide transition circuit for transmitting a high-frequency signal, the hollow-waveguide-to-planar-waveguide transition circuit comprising:

a dielectric substrate having a first main surface and a second main surface which face each other in a thickness direction of the dielectric substrate;

one or more strip conductors formed on the first main surface, extending along a first in-plane direction determined in advance;

a ground conductor formed on the second main surface to face the one or more strip conductors in the thickness direction;

one or more slots formed in the ground conductor and extending in a second in-plane direction different from the first in-plane direction on the second main surface;

a coupling conductor formed at a position to be electrically coupled with the one or more strip conductors on the first main surface, and disposed at a position facing the one or more slots in the thickness direction; and

one or more branch conductor lines branching from an end portion of the coupling conductor in the second in-plane direction on the first main surface, each of the branch conductor lines having a respective base portion branching from the coupling conductor and having a corresponding tip portion that is an electrically open,

wherein the coupling conductor is disposed physically away from the one or more strip conductors.

16. The hollow-waveguide-to-planar-waveguide transition circuit according to claim 15, wherein:

the one or more strip conductors include a first strip conductor and a second strip conductor which are arranged separately from each other; and

the coupling conductor includes a first recessed portion that surrounds an end portion of the first strip conductor facing the coupling conductor, and includes a second recessed portion that surrounds an end portion of the second strip conductor facing the coupling conductor.