Tunable patch antenna

1. A tunable patch antenna, comprising:

a dielectric substrate having a first surface and a second surface, said first surface being parallel to said second surface, said substrate having a geometric center common to said first surface and said second surface;

an electrically-conductive sheet coupled to said first surface;

a patch assembly coupled to said substrate at said second surface thereof, said patch assembly including an electrically-conductive base fixedly coupled to said second surface and an electrically-conductive disk rotatably coupled to said substrate for rotation relative to said base, said disk being in contact with said base;

said base having a substantially circular void passing through it wherein a perimeter region of said base circumscribes said void, said base having an electrically-conductive run extending from said perimeter region to a feedpoint location within said void and offset from said geometric center of said substrate; and

said disk having a diameter greater than a diameter of said void wherein said disk is in contact with said perimeter region of said base, said disk having a slot cut through it, said slot aligned with a center of said disk.

2. A tunable patch antenna as in claim 1 , wherein said slot is symmetrically disposed about said center of said disk.

3. A tunable patch antenna as in claim 1 , wherein said slot is filled with a dielectric material.

4. A tunable patch antenna as in claim 3 , wherein said dielectric material comprises air.

5. A tunable patch antenna as in claim 1 , wherein a center of said void is aligned with said geometric center of said substrate, and wherein said center of said disk is aligned with said center of said void.

6. A tunable patch antenna as in claim 1 , further comprising a screw passing through said center of said disk and threadably engaged with said substrate at said geometric center thereof.

7. A tunable patch antenna as in claim 1 , wherein each of said substrate, said sheet, and said base is rectangular.

8. A tunable patch antenna, comprising:

a rectangular dielectric substrate having a first surface and a second surface, said first surface being parallel to said second surface, said substrate having a geometric center common to said first surface and said second surface;

an electrically-conductive sheet covering and coupled to said first surface;

a patch assembly coupled to said substrate at said second surface thereof, said patch assembly including a rectangular electrically-conductive base fixedly coupled to said second surface and an electrically-conductive disk rotatably coupled to said substrate for rotation relative to said base, said disk being in contact with said base;

said base having a substantially circular void passing through it wherein a perimeter region of said base circumscribes said void, said base having an electrically-conductive run extending from said perimeter region to a feedpoint location within said void and offset from said geometric center of said substrate; and

said disk having a diameter greater than a diameter of said void wherein said disk is in contact with said perimeter region of said base, said disk having a slot cut through it, said slot aligned with a center of said disk.

9. A tunable patch antenna as in claim 8 , wherein said slot is symmetrically disposed about said center of said disk.

10. A tunable patch antenna as in claim 8 , wherein said slot is filled with a dielectric material.

11. A tunable patch antenna as in claim 10 , wherein said dielectric material comprises air.

12. A tunable patch antenna as in claim 8 , wherein a center of said void is aligned with said geometric center of said substrate, and wherein said center of said disk is aligned with said center of said void.

13. A tunable patch antenna as in claim 8 , further comprising a screw passing through said center of said disk and threadably engaged with said substrate at said geometric center thereof.

14. A tunable patch antenna as in claim 8 , wherein said feedpoint is aligned with a central longitudinal axis of said base.

15. A tunable patch antenna, comprising:

a dielectric substrate having a first surface and a second surface, said first surface being parallel to said second surface, said substrate having a geometric center common to said first surface and said second surface;

a rectangular ground plane coupled to said first surface;

a patch assembly coupled to said substrate at said second surface thereof, said patch assembly including a rectangular electrically-conductive base, an electrically-conductive disk, and a screw;

said base being fixedly coupled to said second surface, said base having a substantially circular void passing through it wherein a perimeter region of said base circumscribes said void, said base having an electrically-conductive run extending from said perimeter region to a feedpoint location within said void and offset from said geometric center of said substrate;

said disk having a diameter greater than a diameter of said void wherein said disk is in contact with said perimeter region of said base, said disk having a slot cut through it, said slot aligned with a center of said disk; and

said screw passing through said center of said disk and threadably engaged with said substrate at said geometric center thereof wherein said disk is coupled to said substrate.

16. A tunable patch antenna as in claim 15 , wherein said slot is symmetrically disposed about said center of said disk.

17. A tunable patch antenna as in claim 15 , wherein said slot is filled with a dielectric material.

18. A tunable patch antenna as in claim 17 , wherein said dielectric material comprises air.

19. A tunable patch antenna as in claim 15 , wherein said feedpoint is aligned with a central longitudinal axis of said base.