Patent ID: 6545647
Filing Date: 2003-04-08
Classification: H01Q

Abstract:
An antenna system comprising:(a) a high impedance surface having a relatively higher impedance at a frequency of interest and having a relatively lower impedance at frequencies higher and lower than the frequency of interest; (b) a set of elongate wire antennas disposed on said high impedance surface with their major axes disposed immediately adjacent said high impedance surface, each elongate antenna having a feed end arranged such that the feed end of each elongate wire antenna is disposed closer to a central portion of said high impedance surface than to a peripheral portion of said high impedance surface, each elongate wire antenna having a distal end directed towards the peripheral portion of said high impedance surface; (c) each elongate wire antenna being associated with an impedance matching stub attached by a first end of the stub at the feed end the associated wire antenna, each impedance matching stub having a distal end remote from the first end thereof, the distal ends of said stubs being disposed closer to the central portion of the high impedance surface than are the first ends thereof; and (d) an antenna coupling arrangement coupled to the feed ends of said antennas for passing circularly polarized electromagnetic signals received by the antenna system to a first output thereof and for passing vertically polarized electromagnetic signals received by the antenna system to a second output thereof.