Broadband quadrifilar helix with high peak gain on the horizon

摘要

The invention concerns a quadrifilar helix antenna that has four orthogonal conductive elements helically wound around a common axis. Each of the conductive elements can have between 3 to 7 turns about the common axis at a pitch of between 45 to 65 degrees. Further, each turn has a diameter of about 0.13 wavelengths to 0.27 wavelengths. A feed coupler excites each of the orthogonal conductive elements in phase quadrature at a feed point located at a first end of the antenna adjacent to a ground plane. The resulting antenna can have an axial length of about 2.3 wavelengths to 6.9 wavelengths. Unlike conventional quadrifillar helix antennas, an opposing end of each of the conductive elements distal from the feed point forms an open circuit. The antenna configured as described can have a peak gain on horizon when the common axis is oriented vertically.