Research On The Application Of Physical Optics Method In The Problem Of Electromagnetic Interference Of Satellites

Physical optics(PO) algorithm is a very efficient method for high frequency electromagnetic computation. This algorithm is widely used in the electromagnetic scattering calculation of the electrically large object. However, with the expansion of computing needs, the original PO algorithm is difficult to meet the needs of the ultra large target. In this paper, the algorithm is improved based on the original PO algorithm.The improvement of PO algorithm is mainly in the following three aspects.First, a fast PO algorithm is derived, which the mesh generation is frequency independent. In the algorithm, the target model is divided into triangular meshes. The integral expression of the scattered field of PO is solved in the triangular surface element range and the analytical expression of the scattered field is obtained. In the new algorithm, the dimension of the surface element is independent of frequency. That is, the mesh can be large enough to save computation time and computer memory.Second, the fast time domain physical optics(TDPO) algorithm is derived in this paper. TDPO algorithm is the time domain version of the PO algorithm, and the development of the algorithm is less and less. Firstly, the computational model is divided into triangular mesh. Then the time derivative of the integral formula of TDPO scattering field is converted to the derivative of space. The appropriate excitation source is selected and the integral is solved in the triangular area and the expression of the time domain scattered field is obtained. Finally, using the idea of transfer function, the expression is extended to the case of arbitrary incidence. In addition, the dimension of the surface element is independent of frequency.Third, this paper accelerates the process of eliminating the hidden surface element in PO algorithm. The time complexity of the original mutual occlusion judgment process is very high, which limits the large-scale computation of PO algorithm. This paper uses the divide and conquer algorithm to speed up the mutual occlusion judgment process. As a result, the calculation speed of the PO algorithm is several times of the original.In addition, the PO algorithm is used to solve the problem of the electromagnetic compatibility of the satellite. In this paper, the electromagnetic radiation of electric propulsion is replaced by electric dipole. Then the electromagnetic interference of the satellite sensing device and communication antenna is calculated by PO algorithm. The difference of electromagnetic interference caused by different position of electric propulsion is analyzed and it provides reliable reference for the problem of real satellite electromagnetic interference.