Lightweight antenna attachment structure
The present invention relates to lightweight antenna arrays and more particularly to an attachment mechanism for attaching a lightweight antenna array to a structure. In one embodiment, an antenna structure includes a platform having a first coefficient of thermal expansion; an antenna panel having a second coefficient of thermal expansion different from the first coefficient, and having first and second opposite ends; and a support structure mounting the panel to the platform. The support structure includes a first spacer element with a first height at the first end of the panel, and a second spacer element with a second height less than the first height between the first and second ends of the panel; a first adhesive layer adhering each spacer element to the platform; and a second adhesive layer adhering each spacer element to the antenna panel. A yield strength of the adhesive layers is less than a yield strength of the spacer elements.
1. An antenna structure comprising:
a platform having a first coefficient of thermal expansion;
an antenna panel having a second coefficient of thermal expansion different from the first coefficient, and having first and second opposite ends; and
a support structure mounting the panel to the platform, the support structure comprising:
a first spacer element with a first height at the first end of the panel, and a second spacer element with a second height less than the first height between the first and second ends of the panel;
a first adhesive layer adhering each spacer element to the platform; and
a second adhesive layer adhering each spacer element to the antenna panel,
wherein a yield strength of the adhesive layers is less than a yield strength of the spacer elements.
2. The antenna structure of claim 1 , wherein each spacer element is mounted to the platform only by the first adhesive layer.
3. The antenna structure of claim 2 , wherein the antenna panel is mounted to the platform only by the support structure.
4. The antenna structure of claim 3 , wherein the first spacer element is approximately 1 inch in height and 0.5 inches in diameter, and the second spacer element is approximately 0.5 inches in height and 0.5 inches in diameter.
5. The antenna structure of claim 1 , wherein the spacer elements comprise foam.
6. The antenna structure of claim 5 , wherein the foam comprises polymethacrylimide.
7. The antenna structure of claim 5 , wherein the foam comprises an elastic modulus of approximately 0.05 Msi.
8. The antenna structure of claim 1 , wherein the platform comprises a high-altitude balloon.
9. The antenna structure of claim 1 , wherein the first adhesive layer comprises an elongation of over 300%.
10. The antenna structure of claim 1 , wherein a top surface of each of the first and second spacer elements is flat and a bottom surface of each of the first and second spacer elements is curved.
11. The antenna structure of claim 1 , wherein the spacer elements are adhered to a curved surface of the platform.
12. The antenna structure of claim 1 , wherein the first spacer element is substantially twice as great in height as in diameter.
13. The antenna structure of claim 1 , wherein an elastic modulus of the spacer elements is between approximately 0.03-0.06 Msi.
14. The antenna structure of claim 1 , wherein a density of the spacer elements is between approximately 0.005-0.01 lb/in 3 .
15. The antenna structure of claim 1 , wherein an ultimate strength of the spacer element is between approximately 0.5-1.5 ksi.
16. An antenna structure comprising:
a platform having a curved surface;
an array of antenna panels; and
first and second blocks mounting each panel to the curved surface, wherein the first and second blocks have first and second heights, respectively, that are different from each other,
wherein each block is adhered to the curved surface,
wherein the blocks comprise a foam material;
wherein each block is approximately 0.5 inches in width, and
wherein the blocks are spaced apart from each other by approximately 2-5 inches.
17. The antenna structure of claim 16 , wherein the curved surface is an inner surface of the platform.
18. The antenna structure of claim 16 , wherein the curved surface is an outer surface of the platform.
19. A method of mounting an antenna panel to a platform, comprising:
providing a platform having a first coefficient of thermal expansion;
providing an antenna panel having a second coefficient of thermal expansion different from the first coefficient, and having first and second opposite ends; and
mounting the panel to the platform, comprising:
providing a first spacer element with a first height at the first end of the panel;
providing a second spacer element with a second height less than the first height between the first and second ends of the panel;
adhering each spacer element to the platform with a first adhesive layer; and
adhering each spacer element to the antenna panel with a second adhesive layer,
wherein a yield strength of the adhesive layers is less than a yield strength of the spacer elements.