Patent ID: 7999755
Filing Date: 2011-08-16
Classification: H01Q

Abstract:
1. A QHA antenna comprising: a plurality of helical arms, each comprising a conductor extending a length in a helical winding direction about a longitudinal axis, each having a first distal end and a second distal end; and a differential termination phase shift feed network, having an input port, a first phase shift output port coupled to a first helical conducting arm, a second phase shift output port coupled to a second helical conducting arm, a third phase shift output port coupled to a third helical conducting arm, a fourth phase shift output port coupled to a fourth helical conducting arm, a first isolation port, a second isolation port, and a differential impedance element coupled between the first isolation port and the second isolation port, wherein the differential termination phase shift feed network further includes a first directional transmission path, having a first phase shift, from the input port to the first phase shift output port, a second directional transmission path, having a second phase shift, from the input port to the second phase shift output port, a third directional transmission path, having a third phase shift, from the input port to the third phase shift output port, and a fourth directional transmission path, having a fourth phase shift, from the input port to the fourth phase shift output port, and wherein the differential termination phase shift feed network further includes a first reverse directional path from the first phase shift output port to the first isolation port, a second reverse directional path from the second phase shift output port to the first isolation port, a third reverse directional path from the third phase shift output port to the second isolation port, and a fourth reverse directional path from the fourth phase shift output port to the second isolation port.