TECHNICAL FIELD

This disclosure is generally directed to geodesic antennas. More specifically, this disclosure is directed to modified ground planes to increase gains in element patterns of geodesic antennas.

BACKGROUND

Geodesic antennas are antennas in which their antenna elements contribute to beam patterns in all degrees in azimuth. Some geodesic antennas include cones that help to direct electromagnetic energy, where the cones define lens apertures of the geodesic antennas. Geodesic lens apertures have many advantages, including simplicity of design. Due to their ease of construction and design, geodesic lens apertures are well-suited for applications that require 360° coverage in azimuth. However, electromagnetic energy is typically provided at one end of a cone, and some of the electromagnetic energy in the form of geodesic rays can combine on the other side of the cone and create an interferometer pattern. This interferometer pattern causes phase disturbances that complicate functions such as beam steering calculations and can result in formed beams with higher side lobes.

SUMMARY

This disclosure provides modified ground planes to increase gains in element patterns of geodesic antennas.

In a first embodiment, a geodesic antenna includes an outer cone. The geodesic antenna also includes an inner cone positioned partially within the outer cone and, together with the outer cone, defining an electromagnetic waveguide. The geodesic antenna further includes multiple driven elements configured to generate electromagnetic waves in a space between the outer and inner cones. In addition, the geodesic antenna includes a ground plane configured to reflect first electromagnetic waves of the generated electromagnetic waves back into the space between the outer and inner cones. The ground plane has a geometric design that prevents at least some second electromagnetic waves of the generated electromagnetic waves from being reflected from the ground plane and forming an interferometer pattern.

In a second embodiment, a method includes generating electromagnetic waves in a space between outer and inner cones of a geodesic antenna. The method also includes using a ground plane of the geodesic antenna to reflect first electromagnetic waves of the generated electromagnetic waves back into the space between the outer and inner cones. The ground plane has a geometric design that prevents at least some second electromagnetic waves of the generated electromagnetic waves from being reflected from the ground plane and forming an interferometer pattern.

Other technical features may be readily apparent to one skilled in the art from the following figures, descriptions, and claims.

