Comparative Analysis of Sparse Structures Characteristics of X-Band Reflector Antenna at Different Frequencies

As is known, the current distribution in an antenna structure varies at different frequencies within the operating frequency range. Meanwhile, the sparse wire grid (WG) structure obtained after applying the optimal current grid approximation (OCGA) and its modifications depends on the current distribution in the original WG structure. In this paper, the metal surface of a reflector antenna operating in the X-band was approximated using WG. The influence of frequency selection on the sparse structure, after applying OCGA and its modifications to the original WG structure, was analyzed. The antenna characteristics obtained for the original WG were compared with those obtained experimentally for the solid metal antenna prototype. The comparison showed good agreement and proved the feasibility of using the original WG structure to replace the solid metal structure. The comparative analysis of the sparse WG structure characteristics indicated that the sparse structures based on the original WG current distribution at the lowest frequency in the operating frequency range exhibited the smallest differences compared to those of the original WG structure. Additionally, the characteristics of the sparse antennas generated at high frequencies in the operating range are less influenced by changing the GEET value than at low frequencies. This comparative analysis may help manufacturers select the appropriate frequency at which OCGA and its modifications generate a suitable sparse WG reflector antenna to meet specific requirements.