Patent ID: 7084815

Claim:
An antenna system comprising: a grounded substrate; a first differential feed patch antenna that includes a first radiating system coupled to the grounded substrate and a first feed system having two feed points for providing a first differential feed signal, wherein the first radiating system resonates in response to an excitation by the first differential feed signal; and a second differential feed patch antenna being separated from the first differential feed patch antenna by a first distance, the second differential feed patch antenna including a second radiating system coupled to the grounded substrate and a second feed system having two feed points for providing a second differential feed signal, wherein the second radiating system resonates in response to an excitation by the second differential feed signal, wherein at least a portion of the second differential feed patch antenna serves as a ground plane for the first differential feed patch antenna, and wherein the first radiating system resonates at a higher frequency than the second radiating system.