用矩量法研究直升机高频天线电磁特性的旋翼调制效应

 基于面元模型的矩量法与快速多极子方法结合分析了直升机机载高频通信天线电磁特性的旋翼调制效应。通过三维计算机辅助实体建模技术,建立了一个尺度与真实直升机相当的仿真模型,实现了机体表面网格的自动剖分。应用准静态法和FFT技术,计算分析了旋转桨叶对天线辐射场幅度和频率的调制效应,还分析了桨叶旋转对天线输入导纳和互导纳的影响。计算结果表明,旋转桨叶对直升机机载天线辐射场产生了显著的影响。本方法亦适用于其它类型的直升机和其它具有旋转桨叶的载体上天线电磁特性的分析。

On Helicopter Rotor-blade Modulation of HF Antenna Electromagnetic Behavior Using Method of Moments

The effects of helicopter rotor-blade modulation on the electromagnetic behavior of HF antennas mounted on the airframe are analyzed by method of moments (MoM) with fast multipole method (FMM) based on a surface patch model. By 3D computer aided modeling, a full size model is constructed and the surface meshing of the model is accomplished automatically. Based on these techniques, the modulation effects of rotating blades on the magnitude and frequency of the antenna radiation field are calculated by the quasi-stationary method in combination with fast Fourier transform (FFT) algorithm. Furthermore, the variation of the input admittance and mutual admittance of the antennas are analyzed when the blades rotate. The computed results show that the antenna radiation field is interfered severely by the rotating blades. These techniques can also be used to the investigations on the electromagnetic behavior of antennas mounted on other types of helicopters and platforms with rotating blades.