FDTD Method For Electromagnetic Wave Oblique Incidence In Plasma Medium

When fly in the near-space, the hypersonic aircraft’s surface temperature will bevery high because of the friction between air and the aircraft. The high temperaturewill cause surface air ionization forming a plasma layer around the aircraft which isknown as “plasma sheath”. The plasma sheath will attenuate the electromagnetic wavegreatly and block the communication between hypersonic aircrafts and ground stations.This phenomenon is called “blackout”. So the research on the propagation ofelectromagnetic wave in the plasma sheath is of great important.In real term, because of the relative position of vehicle’s antenna and groundstation, the electromagnetic wave always oblique incidence on the plasma sheath at acertain angle. This paper use FDTD (finite-difference time-domain) method to studythe plasma sheath effects on the oblique incidence electromagnetic wave to providereference for the communication channel modeling.In FDTD method, the questions of oblique incidence is always solved in the2-Dmodel. This paper solves the problem by using the1-D FDTD method, avoiding thetrouble to introduce plane wave in2-D model and improving the computationalefficiency greatly. At the same time, the introduction of2-D oblique incidence planewave will cause errors and the use of the1-D method can also improve the precision.In this paper, the correctness of the algorithm is certified by the comparing with theanalytical solution.When magnetic field exist in plasma medium, the plasma dielectric properties willbecome better, which will reduce the reflection and attenuation of the electromagneticwave and improve the communication quality. This paper use the SO-FDTD (shiftoperator finite-difference time domain SO-FDTD) method to study the characteristic ofthe propagation of the electromagnetic wave. Because the dielectric coefficient ofmagnetized plasma is a tensor, the transmission coefficient and reflection coefficient ofthe plasma characteristic wave (left-hand circular polarization and right-hand circularpolarization) is studied in this paper.