Analysis of electromagnetic wave radiation of hypersonic vehicle covered by plasma sheath

This hypersonic vehicle with plasma sheath can be seen as one kind of media with nonuniform structure, negative permittivity and electrically large size when interacting with high frequency electromagnetic waves. Such features bring challenge to the existing electromagnetic numerical methods. In this paper, the hybrid finite element-boundary integral-multilevel fast multipole algorithm (FE-BI-MLFMA) is used to simulate the antenna radiation of hypersonic vehicle coated by plasma sheath. The plasma sheath is inhomogeneous and mapped from the fluid mesh to electromagnetic mesh. The radiation patterns are calculated in different heights and speeds. The simulation data indicates that the effect of plasma sheath on the radiation performance can be alleviated by increasing the working frequency or deploying the antenna to the tail of the vehicle where the electron density is much lower. In addition, some interesting phenomena have been observed such as the enhancement, the reflection and deflection of the main lobe of the radiation pattern.