摘要 |
A patch antenna in accordance with the present invention comprises a patch optionally surrounded by a top ground plane, a feed line disposed beneath the patch and separated therefrom by a thin substrate, a middle ground plane separated from the feed line by another thin substrate, and a bottom ground plane disposed beneath the middle ground plane and preferably separated therefrom by foam or another lightweight dielectric layer. Conductive vias run between the top ground plane and the middle ground plane as well as from the middle ground plane to the bottom ground plane. The middle ground plane is essentially annular, defining an opening in the middle thereof, such that there is a dielectric cavity beneath the patch and the feed line in the space defined by the bottom ground plane, the middle ground plane and the vias that run between the middle ground plane and the bottom ground plane. This cavity can be filled with low cost, low weight foam, rather than the heavier, more costly conventional substrates.
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