Waveguide balun having waveguide structures disposed over a ground plane and having probes located in channels
View Patent ↗An apparatus may include one or more conductive surfaces, waveguide structures and/or ports. One or more waveguide structures may include a portion disposed above a conductive surface, an outer conductor, and/or an inner conductor. A first portion of an outer conductor may be connected to a conductive surface. A port end of an outer conductor may be connected to an outer conductor port. An inner conductor may be disposed inside and spaced apart from an outer conductor. An inner conductor port may be connected to an inner conductor. An inner conductor of two or more waveguide structures may be connected to each other. A conductive surface may include at least one aperture portion, which may have a width substantially similar to the width of a waveguide structure. A substrate may be disposed between one or more waveguide structures and a conductive surface for a substantial portion of a waveguide structure.
1. A waveguide balun apparatus, comprising:
a. a conductive surface configured to provide a ground plane for the balun;
b. first and second waveguide structures extending along respective longitudinal paths above the conductive surface, the first and second waveguide structures each including an outer conductor in electrical communication with the conductive surface and an inner conductor disposed inside and spaced apart from the outer conductor, wherein the inner conductor of the first waveguide structure and the inner conductor of the second waveguide structure are electrically connected to one another at respective selected ends of the first and second waveguide structures;
c. first and second longitudinally extending apertures disposed in the conductive surface at a location below the first and second waveguide structures, respectively, each aperture dimensioned to extend along the longitudinal path of the respective waveguide structure;
d. first and second elongated probes electrically connected at the selected end to, and extending away from, the outer conductors of the first and second waveguide structures, respectively; and
e. two probe sidewalls electrically connected to the conductive surface and extending upward from the conductive surface on either side of each of the first and second elongated probes to provide a grounded U-shaped channel about each of the first and second elongated probes.
2. The waveguide balun apparatus of claim 1 , wherein the longitudinal path of the first waveguide structure comprises a meandered path.
3. The waveguide balun apparatus of claim 1 , wherein the first elongated probe tapers to a pointed tip.
4. The waveguide balun apparatus of claim 1 , wherein one or more conductive cross members are disposed across the first and second apertures.
5. The waveguide balun apparatus of claim 1 , wherein the first waveguide structure has a width and the first aperture has a width greater than the width of the first waveguide structure.
6. The waveguide balun apparatus of claim 1 , wherein the first waveguide structure has a width and the first aperture has a width less than the width of the first waveguide structure.
7. The waveguide balun apparatus of claim 1 , comprising a substrate disposed between the conductive surface and the first and second waveguide structures.
8. The waveguide balun apparatus of claim 1 , comprising a first substrate disposed between the first aperture and the first waveguide structure, and a second substrate separated from the first substrate and disposed between the second aperture and the second waveguide structure.
9. A waveguide balun apparatus, comprising:
a. a conductive surface configured to provide a ground plane for the balun;
b. first and second waveguide structures extending along respective longitudinal paths above the conductive surface, the first and second waveguide structures each including an outer conductor in electrical communication with the conductive surface and an inner conductor disposed inside and spaced apart from the outer conductor, wherein the inner conductor of the first waveguide structure and the inner conductor of the second waveguide structure are electrically connected to one another at respective selected ends of the first and second waveguide structures;
c. a substrate disposed between the conductive surface and the first and second waveguide structures;
d. first and second elongated probes electrically connected at the selected end to, and extending away from, the outer conductors of the first and second waveguide structures, respectively; and
e. two probe sidewalls electrically connected to the conductive surface and disposed on either side of each of the first and second elongated probes to provide a grounded channel about each of the first and second elongated probes.
10. The waveguide balun apparatus of claim 9 , wherein the longitudinal path of the first waveguide structure comprises a meandered path.
11. The waveguide balun apparatus of claim 9 , wherein the first elongated probe tapers to a pointed tip.
12. The waveguide balun apparatus of claim 9 , wherein the substrate comprises a first substrate portion disposed between the first waveguide structure and the conductive surface, and a second substrate portion separate from the first substrate portion and disposed between the second waveguide structure and the conductive surface, and wherein the first substrate portion has a width greater than the width of the first waveguide structure.
13. The waveguide balun apparatus of claim 12 , wherein the probe sidewalls extend upward from the conductive surface to provide a grounded U-shaped channel.
14. The waveguide balun apparatus of claim 12 , wherein the first substrate portion is dimensioned to extend along the longitudinal path of the first waveguide structure.
15. The waveguide balun apparatus of claim 9 , wherein the substrate comprises a first substrate portion disposed between the first waveguide structure and the conductive surface, and a second substrate portion separate from the first substrate portion disposed between the second waveguide structure and the conductive surface, and wherein the first substrate portion has a width less than the width of the first waveguide structure.
16. A method of fabricating a waveguide balun apparatus, comprising:
a. providing a conductive surface configured to provide a ground plane for the balun;
b. forming first and second waveguide structures extending along respective longitudinal paths above the conductive surface, the first and second waveguide structures each including an outer conductor in electrical communication with the conductive surface and an inner conductor disposed inside and spaced apart from the outer conductor, wherein the inner conductor of the first waveguide structure and the inner conductor of the second waveguide structure are electrically connected to one another at respective selected ends of the first and second waveguide structures;
c. forming first and second elongated probes electrically connected at the selected end to, and extending away from, the outer conductors of the first and second waveguide structures, respectively; and
d. forming two probe sidewalls electrically connected to the conductive surface and disposed on either side of each of the first and second elongated probes to provide a grounded channel about each of the first and second elongated probes.
17. The method of claim 16 , wherein the conductive surface includes first and second longitudinally extending apertures disposed therein at a location below the first and second waveguide structures, respectively, each aperture dimensioned to extend along the longitudinal path of the respective waveguide structure.
18. The method of claim 16 , comprising provide a substrate disposed between the conductive surface and the first and second waveguide structures.
19. The method of claim 18 , wherein the substrate comprises a first substrate portion disposed between the first waveguide structure and the conductive surface, and a second substrate portion separate from the first substrate portion disposed between the second waveguide structure and the conductive surface, and wherein the first substrate portion has a width greater than the width of the first waveguide structure.
20. The method of claim 19 , wherein the first substrate portion is dimensioned to extend along the longitudinal path of the first waveguide structure.
21. The method of claim 18 , wherein the substrate comprises a first substrate portion disposed between the first waveguide structure and the conductive surface, and a second substrate portion separate from the first substrate portion disposed between the second waveguide structure and the conductive surface, and wherein the first substrate portion has a width less than the width of the first waveguide structure.
22. The method of any one of claims 16 - 20 , wherein the method of fabricating includes a sequential build process comprising disposing a plurality of layers over the conductive surface,
wherein the layers comprise layers of a conductive material and layers of a sacrificial material, thereby forming a layered structure above the conductive surface comprising the first and second waveguide structures, the first and second elongated probes, and the two probe sidewalls.