Design and optimization of a corrugated horn feed with axial and radial slots

The optimization method of horns that combine axial and radial slots was studied. Body of revolution finite difference time domain algorithm was applied in analyzing horns. A corrugated horn working in the Ku band was designed and optimized using covariance matrix adaptation-evolution strategy for better aperture efficiency. The optimized horn was fabricated and tested. Simulated and measured results show a good agreement in both impedance matching and radiation patterns in 10.7-12.75 GHz. The aperture efficiency is better than 78% with the feed illuminating a classical Cassegrain antenna, which proves the effectiveness of this optimization method.