Patent ID: 7183991

Claim:
An antenna horn with enhanced aperture efficiency, the antenna horn comprising: a first outward flare section, a second cylindrical flare section, a third outward flare section, and a fourth outward flare section; wherein the first outward flare section is adapted to be coupled to a waveguide and the fourth outward flare section has an aperture through which electromagnetic energy is coupled to or from space; wherein the slopes and lengths of the first outward flare section, the second cylindrical flare section, the third outward flare section, and the fourth outward flare section are selected to enhance desirable electromagnetic modes at the aperture, thereby enhancing the aperture efficiency and antenna gain; wherein the first outward flare section is coupled to the second cylindrical flare section without a step discontinuity; wherein the second cylindrical flare section is coupled to the third outward flare section without a step discontinuity; wherein the third outward flare section is coupled to the fourth outward flare section without a step discontinuity; wherein the desirable electromagnetic modes are TE modes and the first outward flare section, the second cylindrical flare section, the third outward flare section, and the fourth outward flare section are selected to enhance the TE modes and suppress any TM modes at the aperture.