Low-profile vertically-polarized omni antenna

An omni-directional antenna core assembly for use in a stacked, multi-ground plane antenna, comprising:

• a conductive ground plane defining an axis normal to the conductive ground plane;
• a plurality of conductive plates projecting orthogonally from the conductive ground plane and angularly spaced about a central axis;
• each conductive plate having an edge extending radially outboard from the central axis, the edge defining a first region and a second region radially outboard of the first region, the first region diverging linearly away from the conductive ground plane as the radial distance increases from the central axis and the second region defining an arcuate shape which diverges exponentially away from the conductive ground plane and defining a radius of curvature between about 0.05λ to about 0.1λ, wherein λ is a wavelength of a transmitted antenna frequency.