Ferrite waveguide circulator with thermally-conductive dielectric attachments

Abstract

The present invention improves the geometry of ferrite circulators in order to increase the average power handling by decreasing the temperature rise in the ferrite and associated adhesive bonds. Embodiments of the present invention utilize dielectric attachments on the sides of the ferrite element, which maximizes the area of contact and minimizes the path length from the ferrite element out to the thermally conductive attachments.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide further understanding of the invention and are incorporated in and constitute a part of this specification. The accompanying drawings illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the figures:

FIG. 1 shows a top view of a conventional ferrite element;

FIG. 2 shows a top view of a conventional single-junction waveguide circulator structure;

FIG. 3 shows a partial side view of a conventional single-junction waveguide circulator structure;

FIG. 4 shows a perspective view of the internal portion of a waveguide circulator structure incorporating thermally-conductive, rectangular dielectric attachments on the sides of the resonant section and faces of the ferrite element according to one embodiment of the present invention;

FIG. 5 shows a top view of a waveguide circulator structure having thermally-conductive, rectangular dielectric attachments on the sides of the resonant section and faces of the ferrite element according to one embodiment of the present invention;

FIG. 6 shows a partial side view of the structure shown in FIG. 5;

FIG. 7 shows a top view of a waveguide circulator structure incorporating thermally-conductive, V-shaped dielectric attachments on the sides of the resonant section of the ferrite element according to an aspect of the present invention;

FIG. 8 shows a top view of a waveguide circulator structure incorporating thermally-conductive, dielectric attachments, tapered in profile, on the sides of the resonant section of the ferrite element according to an aspect of the present invention;

FIG. 9 shows a partial side view of the structure shown in FIG. 8;

FIG. 10 shows a top view of a waveguide circulator structure incorporating thermally-conductive, rectangular dielectric attachments on the sides and faces of the ferrite element according to an aspect of the present invention; and

FIG. 11 shows a top view of a waveguide circulator structure incorporating thermally-conductive, rectangular dielectric attachments on the sides and faces of the ferrite element and incorporating multiple dielectric spacers to fill the gaps above and below the ferrite element according to an aspect of the present invention.

Claims

1. A ferrite waveguide circulator, comprising: a waveguide structure having an internal cavity, the waveguide structure including a plurality of ports extending from the internal cavity;at least one ferrite element disposed in the internal cavity, said ferrite element including at least one leg having at least two side surfaces and one face surface; andat least one thermally-conductive dielectric attachment affixed to at least one of said side surfaces of the ferrite element.

2. The ferrite waveguide circulator according to claim 1, wherein the dielectric attachment is one of boron nitride, aluminum nitride, beryllium oxide, and combinations thereof.

3. The ferrite waveguide circulator according to claim 1, wherein the dielectric attachment has a thermal conductivity of at least 0.01 W/(in.2·° C.).

4. The ferrite waveguide circulator according to claim 1, wherein the dielectric attachment is less than or equal to about 0.02″ thick for operating ranges about 20 GHz.

5. The ferrite waveguide circulator according to claim 1, further comprising at least one thermally-conductive dielectric attachment affixed to at least one of said face surfaces of the ferrite element.

6. The ferrite waveguide circulator according to claim 5, further comprising a dielectric transformer, wherein said at least one thermally-conductive dielectric attachment affixed to at least one of said face surfaces is located between said face surface and said dielectric transformer.

7. The ferrite waveguide circulator according to claim 1, wherein the at least one thermally-conductive dielectric attachment affixed to at least one of said face surfaces has a first surface area covering the face surface of the ferrite element that exceeds a second surface area of the dielectric transformer that is adjacent to the first surface area.

8. The ferrite waveguide circulator according to claim 6, wherein said dielectric attachment covers at least 50% of the surface area of the face surface.

9. The ferrite waveguide circulator according to claim 1, wherein the dielectric attachment is affixed to one of said side surfaces and covers at least 5% of the surface area of that side surface.

10. The ferrite waveguide circulator according to claim 1, wherein the ferrite element includes at least two legs, wherein one dielectric attachment is jointly affixed to a side of each of two legs.

11. The ferrite waveguide circulator according to claim 1, further comprising at least one dielectric spacer disposed on an outer surface of the at least one ferrite element.

12. The ferrite waveguide circulator according to claim 1, further comprising at least one empirical matching element disposed within the internal cavity.

13. The ferrite waveguide circulator according to claim 1, wherein a plurality of thermally-conductive dielectric attachments form a perimeter around the ferrite element.

14. The ferrite waveguide circulator according to claim 1, further comprising a least one filler, wherein the filler substantially fills a span between the ferrite element and a proximate opposing wall of the waveguide structure.

15. A ferrite waveguide circulator, comprising: a waveguide structure having an internal cavity, the waveguide structure including a plurality of ports extending from the internal cavity;at least one ferrite element disposed in the internal cavity, said ferrite element including at least one leg having at least two side surfaces and one face surface; andat least one thermally-conductive dielectric attachment affixed to at least one of said face surfaces of the ferrite element.

16. The ferrite waveguide circulator according to claim 15, further comprising a quarter-wave dielectric transformer extending from said face surface, wherein the at least one thermally-conductive dielectric attachment has a surface area covering the face surface of the ferrite element that exceeds the surface area of quarter-wave dielectric transformer covering the face surface.

17. The ferrite waveguide circulator according to claim 15, wherein the dielectric attachment is one of boron nitride, aluminum nitride, beryllium oxide, and combinations thereof.

18. The ferrite waveguide circulator according to claim 15, wherein the dielectric attachment has a thermal conductivity of at least 0.01 W/(in.2·° C.).

19. The ferrite waveguide circulator according to claim 15, wherein the dielectric attachment is less that or equal to about 0.02″ thick for operating ranges about 20 GHz.

20. The ferrite waveguide circulator according to claim 15, wherein said dielectric attachment covers at least 50% of the surface area of the face surface.

21. The ferrite waveguide circulator according to claim 15, further comprising a filler material to eliminate air gaps between the at least one of the surfaces of the ferrite element and the waveguide structure.

22. A system for circulating microwaves in a waveguide, comprising: a waveguide structure having an internal cavity forming an input port and one or more output ports;a ferrite element that substantially exclusively couples microwaves from said input port to one of said output ports, wherein the substantially exclusive coupling is responsive to an activation of at least one magnetizable winding associated with said ferrite element; andat least one thermally conductive dielectric attachment affixed to the ferrite element so as to conduct thermal energy away from said ferrite element.

23. The system according to claim 22, wherein the dielectric attachment has a thermal conductivity of at least 0.01 W/(in.2·° C.).

24. The system according to claim 22, wherein the ferrite element includes at least one leg having at least two side surfaces and one face surface and the at least one thermally conductive dielectric attachment is affixed to at least one of said two side surfaces and one face surface.