Circularly polarized, broadside firing, multihelical antenna

摘要

An antenna for radiating substantially circularly polarized signals omnidirectionally about and substantially broadside a support mast is provided by conductors wound about the mast. The conductors are spaced from the mast and are equally distributed about the periphery of the mast with signals coupled to the conductors such that the phase of the signal coupled to one conductor is 180 DEG out of phase with the phase of the signal coupled to adjacent conductors and is in phase with the phase of the signal coupled to the alternate conductor. The number of conductors wound about the mast is selected to be twice the mode number wherein the mode number is the number of 360 DEG linearly phase changes of the electric field in one circumference. The pitch angle of the helically wound conductors and the radius of the helix formed by the conductors is selected to achieve substantially, circularly polarized radiation substantially perpendicular or broadside the lengthwise axis of the mast.