Abstract: An antenna feed for a stackable antenna system includes a polarization converter that continuously surrounds an omnidirectional antenna. Electromagnetic radiation emitted by the omnidirectional antenna and having an initial polarization passes through the first polarization converter, which converts the initial polarization into a non-vertical linear polarization. A feedline located outside of the first polarization converter forms a helix that wraps around the first polarization converter such that it runs perpendicularly to the non-vertical linear polarization. When the width of the feedline is sufficiently small, electrons in metal of the feedline will not be excited by the radiation, and the radiation will transmit through the feedline with minimal impact on the omnidirectional antenna's gain profile. The feedline may be used to feed a second antenna located vertically above the omnidirectional antenna.