结构天线概念及其在机载低频多天线系统设计中的关键技术研究

Low frequency (HF/VHF band) aircraft communication systems have found wide applications in particular areas such as military and disaster restorations. Low frequency aircraft multi-antenna system is the key sub-system, and it greatly affects the performance of the low frequency communication system. Because of the large resonant length of antennas and the physical size of aircraft platforms are generally comparable with the wavelength in the HF/VHF band, the design of low frequency aircraft integrated multi-antennas with satisfactory radiation performance, electromagnetic compatibility performance, and aerodynamic performance becomes a rather challenging task. Based on the structural antenna concept, this project will deeply explore the radiation modes of the platform itself and develop high efficient excitation structures. By exciting the radiation modes of the aircraft, we aim to achieve low frequency aircraft integrated multi-antenna systems with excellent radiation efficiency, fine electromagnetic compatibility performance, and platform embedded or conformal antenna geometry. The main work of this project includes: (a) high efficient and accurate modal analysis methods for complex aircraft platforms; (b) efficient excitation methods for mode currents over complex aircraft platforms; and (c) systematic design methodology for low frequency aircraft multi-antenna systems based on the structural antenna concept. This project employs rigorous computational electromagnetic theories and numerical techniques as the foundations of the whole work, and balances the theoretical analysis, numerical simulation, and experimental demonstration during the implementation of the project. With these approaches, we will go further to develop many novel inductive/capacitive electromagnetic coupling structures, propose systematic approaches to determine the optimal placement of excitation structures, and finally realize several low frequency aircraft multi-antenna system through experimental validation. In a word, the efforts in this project will provide rigorous theoretical guidelines, high efficient and accurate analysis/design methods, and several novel electromagnetic coupling structures through demonstrative experiment validations for further high-performance low frequency aircraft multi-antenna system developments.

低频（HF/VHF频段）机载通信系统在军事及灾后恢复等特殊领域有着广泛应用。低频机载多天线系统是其关键子系统，对系统性能具有重要影响。由于天线谐振长度及飞行平台尺寸与HF/VHF频段波长相当，实现同时满足辐射性能、电磁兼容性能、以及空气动力学特性的低频机载多天线系统极富挑战性。本项目旨在基于结构天线概念，通过研究空天飞行平台自身辐射模式及其激励方式，实现具有良好辐射效率与电磁兼容性能的嵌入式/共形低频机载多天线系统。具体包括：复杂机载平台的高效高精度模式分析方法研究；复杂机载平台模式电流高效激励方法研究；基于结构天线概念的低频机载多天线系统化设计方法研究。本项目以计算电磁学理论与技术为基础，采用理论分析、数值模拟、实验研究并重的研究方法，探索多种新型感性/容性电磁耦合结构，实现若干种通过实验验证的低频机载多天线系统，为未来高性能低频机载多天线系统研制提供可靠的理论依据和系统化的设计方法。

本项目针对机载HF/VHF频段天线在辐射性能（尤其是辐射效率）、电磁隐身、电磁兼容性能、以及空气动力学特性设计方面面临的巨大挑战，突破了结构天线概念及其在机载低频多天线系统设计中的关键技术，突破了结构天线概念在机载低频多天线系统设计中的关键技术，完成了结构天线概念的应用验证，完成了复杂电磁平台的模式分析技术、基于低频机载平台辐射模式的高效波束综合技术、基于结构天线概念的低频机载方向图可重构技术、基于结构天线概念的低频机载多天线系统的电磁兼容设计以及电磁隐身性能评估方法等研究内容。提出了复杂机载平台的高效高精度模式分析方法、提出了多种用于激励机载平台模式电流的高效感性耦合单元与容性耦合单元、建立了基于结构天线概念的低频机载多天线系统的系统化设计方法、提出了包括模式频移技术、模式抑制技术、模式主动设计技术等一系列天线散射模式缩减与调控技术，实现了100 MHz以下波段机载多天线系统的共形低散射设计。基于本项目研究成果，发表IEEE 期刊论文8篇，国际会议论文7篇，申请国家发明专利3项，培养毕业博士2名，硕士生8名，全面完成项目研究目标与预期研究成果。