Design of an ultrabroadband and compact H‐plane sectoral ridged horn‐reflector array

In this paper, an ultrabroadband linear array in which horn‐reflector antennas are used as radiating elements by adding a central ridge to the rectangular waveguide, leading to an increased bandwidth of 3:1. With a reflector embedded in the H ‐plane sectoral ridged horn, a desired narrow beam can be easily achieved. Moreover, due to the compact enclosed structure, the proposed reflector array can not only eliminate the illumination loss but also significantly reduce size compared with those of conventional array‐fed parabolic cylinder antennas. Good agreement between the calculated and measured results is obtained, showing that the proposed antenna array has a high aperture efficiency of about 80%, a ±45° scanning range in the E ‐plane and 5° beam coverage with low side lobes in the H ‐plane within the frequency range of 6–18 GHz.