Research on EM Shielding Mechanism of the Plasma-Sheath-Covered Target

Abstract

When a near-space hypersonic vehicle flies at a velocity of several Machs, a plasma sheath is created on its surface. The plasma sheath is a complex electromagnetic (EM) medium composed of many charged particles, producing a series of EM effects on EM waves. In this article, based on the numerical calculation results of the plasma sheath flow field at typical altitudes, the spatial distribution characteristics of the reflection intensity of the typical reference area on the vehicle surface are solved. The EM shielding effect of the plasma-sheath-covered target is revealed by the incident depth and the maximum reflection position of the EM wave in the plasma. By analyzing the influence of different flight altitudes and carrier frequencies on the reflection characteristics of each typical vehicle area, the variation law of the EM shielding effect of the plasma-sheath-covered target is obtained. The research results reveal the EM shielding mechanism of plasma sheath and provide a theoretical basis for radar detection and radar cross section (RCS) measurement of the plasma-sheath-covered target.