Electromagnetic Field Analysis and EMI Evaluation of Radio Altimeter and 5G Sub-6 GHz Band in Aircraft Environment

This study proposes a numerical analysis method suitable for EMC evaluations of aircraft. By employing a detailed numerical model that replicates both the external shape and internal structures of an aircraft, combined with large-scale parallel FDTD analysis, the far-field radiation characteristics of a radio altimeter frequency band antenna mounted on the aircraft's underside were evaluated. The results demonstrate that this approach achieves higher accuracy in EMI evaluations compared to conventional methods. Criteria for determining the appropriate cell size for EMC evaluations in the radio altimeter and 5G Sub-6 GHz frequency bands were also established. Additionally, the study highlights the effectiveness of large-scale FDTD analysis in accurately assessing unwanted radiation and EMI characteristics, such as cross-polarization and upward emissions, providing practical insights for advancing EMC evaluation techniques and aircraft system design.