Patent ID: 7817101

Claim:
An antenna comprising: a common ground plane; a first set of N approximately resonant elements associated with the common ground plane, each of said first set of approximately resonant elements having a length I 2 and wound to form a first helix with an initial diameter d 2 and a height h 2 ; and a second set of N approximately resonant elements associated with the common ground plane, each of said second set of approximately resonant elements having a length I 1 and wound in the opposite direction to the first set of approximately resonant elements to form a second helix that is centrally disposed within the first helix, and has an initial diameter dl and a height h 1 where d 1 is less than d 2 and h 1 is greater than h 2 , wherein the length I 2 of the first set of approximately resonant elements is about equal to the length I 1 of the second set of approximately resonant elements, and wherein the first and second helices are simultaneously operable at the same frequency (f).