Design and Optimization of a New 1–18 GHz Double Ridged Guide Horn Antenna

Abstract

A new design of a broadband 1–18 GHz double ridged guide horn antenna with redesigned feeding section is presented. Several modifications are made in the structure of a conventional double ridged guide horn antenna in order to overcome the deterioration of its radiation pattern at higher frequencies. Using the results of a sensitivity analysis of the most important parameters of the modified structure, it has been optimized by employing the interpolated quasi-Newton method. The resulting antenna not only does not suffer from the known deficiencies of a conventional antenna, but also has smaller physical dimensions and enjoys a better EM performance compared with the conventional one. The feeding section of this antenna is redesigned and the whole antenna has been optimized again to achieve a better VSWR. These modifications resulted in a VSWR of less than 2.7 at lower end of the frequency band and less than 1.8 at the upper end of the band. Reduction in the weight of the antenna and ease of construction are two other advantages of the new antenna.