JP,
The patch antenna works best over an infinite ground plane. Anything bigger is better, where it gets a lot better with just doubling the size, etc. As Bill mentioned, the additional ground plane should be close behind the back of the antenna. Not practical, but ideal would be to have some foil or metal sheet actually in contact with the back of your patch (the antenna is a patch--separated by a dielectric (insulating layer), backed by a larger metal piece--the ground plane). Note that the shield or outer conductor of the cable and patch connector will be connected to the ground plane.
Interesting that you get bad results with the helmet in all orientations.... I wonder if there could be a loose connection somewhere, and when you move around, it loses contact. I'm going to take Bill's advice and read back to those posts where the ground plane was discussed.
Cheers,
Dave
p.s. thanks for not flaming my sketch--it was pretty awful but fast. And, no, I'm not a special ed student
nor a heavy coffee drinker
