High-efficiency transparent microwave antennas
View Patent ↗The present invention provides for inexpensive transparent microwave antennas with high efficiency. Conductors for the antennas are formed from metallic meshes with a net transparency greater than 70% and supported by a clear substrate. The associated antenna gain efficiencies are greater than 50%.
1. A substantially transparent antenna, comprising:
a substantially transparent substrate having first and second sides;
a first and second conductive films respectively carried on said first and second sides wherein:
a) said first conductive film has a first film area and is shaped to define at least one patch and to define a first array of first open spaces whose areas sum to a first open-spaces area that is at least 70% of said first film area; and
b) said second conductive film has a second film area and is shaped to define a around plane and to define a second array of second open spaces whose areas sum to a second open-spaces area that is at least 70% of said second film area.
2. The antenna of claim 1 , wherein said substrate comprises a substantially transparent dielectric material selected from at least one of glass, polystyrene, polycarbonate, air, polyester and acrylic.
3. The antenna of claim 1 , wherein said substrate comprises acrylic.
4. The antenna of claim 1 , wherein said first and second arrays are orthogonal arrays.
5. The antenna of claim 1 , wherein said first and second conductive films comprise a metal.
6. The antenna of claim 1 , wherein said first and second conductive films comprise a metal selected from at least one of aluminum, copper, gold, silver, tin and nickel.
7. The antenna of claim 1 , further including first and second plastic films that each carry a respective one of said first and second conductive films.
8. The antenna of claim 7 , wherein said first and second plastic films comprise polyester.
9. The antenna of claim 1 , wherein said first conductive film defines a plurality of patches and further including feed lines that serially connect said patches.
10. The antenna of claim 9 , wherein said feed lines are defined by a third conductive film having a third film area and shaped to define a third array of third open spaces whose areas sum to a third open-spaces area that is at least 70% of said third film area.
11. The antenna of claim 1 , wherein said first conductive defines a plurality of patches and further including a feed line that connects said patches in parallel.
12. The antenna of claim 11 , wherein said feed line is defined by a third conductive film having a third film area and shaped to define a third array of third open spaces whose areas sum to a third open-spaces area that is at least 70% of said third film area.
13. The antenna of claim 1 , wherein said patch has a substantially rectangular shape.
14. The antenna of claim 1 , wherein said patch has a substantially circular shape.
15. The antenna of claim 1 , further including a cable having first and second elongate conductors wherein at least one of said conductors is directly coupled to a respective one of said first and second conductive films.
16. The antenna of claim 15 , wherein at least one of said first and second conductive films defines a solid area that receives a respective one of said conductors.
17. The antenna of claim 16 , further including a cable having first and second elongate conductors wherein at least one of said conductors is capacitively coupled to a respective one of said first and second films.
18. The antenna of claim 1 , further including an substantially transparent adhesive between said substrate and said first and second films.
19. The antenna of claim 1 , further including at least one suction cup coupled to said substrate for attachment to a support member.
20. The antenna of claim 1 , further including an adhesive coupled to said substrate for attachment to a support member.
21. A substantially transparent antenna, comprising:
a substantially transparent substrate having first and second sides;
first and second conductive films respectively carried on said first and second sides wherein:
a) said first conductive film has a first film area and is shaped to define a dipole and to define a first arras of first open spaces whose areas sum to a first open-spaces area that is at least 70% of said first film area, and
b) said second conductive film has a second film area and is shaped to define a feed line and to define a second array of second open spaces whose areas sum to a second open-spaces area that is at least 70% of said second film area.
22. The antenna of claim 21 , wherein said first and second arrays are orthogonal arrays.
23. The antenna of claim 21 , wherein said first and second conductive films comprise a metal selected from at least one of aluminum, copper, gold, silver, tin and nickel.
24. The antenna of claim 21 , wherein said substrate comprises a substantially transparent dielectric material selected from at least one of glass, polystyrene, polycarbonate, air, polyester and acrylic.
25. The antenna of claim 21 , further including first and second plastic films that each carry a respective one of said first and second conductive films.
26. The antenna of claim 25 , wherein said first and second plastic films comprise polyester.
27. The antenna of claim 21 , further including a cable having first and second elongate conductors wherein at least one of said conductors is directly coupled to a respective one of said first and second conductive films.
28. The antenna of claim 21 , further including a cable having first and second elongate conductors wherein at least one of said conductors is capacitively coupled to a respective one of said first and second films.