大展弦比机翼共形承载天线电性能自适应补偿方法研究

在现代“陆、海、空、天、电”多维空间作战体系中，高空长航时无人机在大范围预警、高机动侦察、险境攻防对抗等方面具有不可替代的作用，在国家战略防御系统占据重要地位。该类无人机的显著特点即采用大展弦比机翼增大其航程和航时。为提高无人机预警探测威力，实现远距离大范围动态目标搜索与跟踪，将天线嵌入机翼蒙皮承载结构形成大展弦比机翼共形承载天线，在不影响飞行器气动性能情况下，极大提高天线的物理口径。大展弦比机翼共形承载天线兼具力学承载与电磁辐射功能，是典型的机械结构与电磁性能紧密耦合的系统。一方面天线作为承载结构时刻承受环境载荷的影响，另一方面，飞行器平台对结构轻量化要求很高，使该类天线通常具有结构质量轻、柔性大、结构基频低等特点，在飞行中尤其是高速机动飞行时更易受载荷影响产生弯曲扭转等大尺度非线性结构变形，导致阵元形貌变化、互耦效应严重，使探测目标偏移、探测距离缩短、抗干扰能力降低。随着飞行器对多功能、高分辨率、高数据率等需求的提升，促使天线向高频段、宽频带、大扫描范围方向发展，环境载荷引起的变形对电性能影响更为严重，最终导致天线服役性能严重恶化，其核心问题即未能突破复杂环境载荷导致的大尺度非线性结构变形对电性能影响，不具备自适应环境载荷影响的能力，这成为制约大展弦比机翼共形承载天线由被动保形到主动调控创新设计的瓶颈。为此，研究结构形貌与电性能之间的形性耦合关系，建立考虑阵元形貌变化与互耦效应的形性耦合模型，揭示位移-电磁关联敏度、阵元互耦表征等影响机理。针对结构形貌难以实时高精度感知问题，提出基于应变的复合结构位移场高精度重构方法。基于形性耦合模型和位移场信息，提出多频点多扫描角下电性能自适应补偿方法以保证宽带宽角范围稳健服役。通过实验验证并完善理论模型与方法。项目为大展弦比机翼共形承载天线服役性能提升以及下一代高频段、宽频带、高性能共形承载天线的创新研制提供理论指导与技术支撑。

Conformal load bearing antenna embedded in high aspect ratio wing has the function of both mechanical load bearing and electromagnetic radiation. It can realize long-distance and large-scale dynamic target search and tracking, which plays an important role in the national strategic defense system. However, on the one hand, the antenna as a load-bearing structure bears the influence of environmental loads at all times. On the other hand, the aircraft platform has high requirements on the lightweight structure, so that this type of antenna usually has the characteristics of light structure, large flexibility, and low structural fundamental frequency. It is more susceptible to large-scale nonlinear structural deformations such as bending and torsion under the influence of environmental loads in flight, which leads to changes in the morphology of array elements and serious mutual coupling effects, resulting in the offset of detection target, the shortening of detection distance and the reduction of anti-interference ability. Due to the unclear strong correlation coupling mechanism of multi factor between the large scale nonlinear structure morphology and electromagnetic performance, there is a lack of effective compensation method to ensure the reliable working performance of the antenna. This has become the bottleneck of the innovative design of conformal load bearing antenna from passive conformal to active control. To this end, the coupling relationship between the structure morphology and electromagnetic performance is studied, and a morphology and electromagnetic performance coupling model that considers the effect of element morphology variation and mutual coupling is established. Based on this, the sensitivity of displacement and electromagnetic correlation and mutual coupling characterization of array elements are revealed. Aiming at the problem that it is difficult to obtain the antenna morphology in real time and high precision, a high-precision reconstruction method for the displacement field of multi-layer composite structure is proposed. Furthermore, based on the coupling model and reconstructed displacement field information, an adaptive compensation method for electromagnetic performance at multi-frequency point and multi-scan angle is proposed to ensure the reliable performance of the antenna in a wide bandwidth and scan range. Finally, the theoretical model and method are verified and improved by experiments. The project aims to provide theoretical guidance and technical support for the improvement of the service performance of the conformal load bearing antenna embedded in high aspect ratio wing and the innovative development of the next generation of conformal load bearing antenna with high-frequency, wide-bandwidth and high-performance.