The mechanism of radar cross section reduction under plasma

This paper explores the mechanism of radar cross section (RCS) reduction under plasma. The Runge–Kutta exponential time differencing–finite difference time domain method is used to compute the radar cross section of a target covered by plasma. Then, a method for analyzing the electromagnetic coupling effect between electromagnetic waves and plasma-covering targets based on field intensity visualization images and a probe is proposed. This method can elucidate the interaction process between electromagnetic waves and plasma-covering targets, ultimately revealing the key finding that the complex multiple reflections between the air–plasma interface and the plasma–metal interface are the fundamental mechanism of radar cross section reduction. Furthermore, the influence of the electron density, collision frequency, plasma thickness, electromagnetic wave frequency, and non-uniform distribution characteristics on the radar cross section reduction is discussed. A radar cross section reduction ridge is discovered in a two-dimensional diagram of radar cross section variation with electron density and electromagnetic wave frequency. It can be observed that the places where radar cross section reduction is more significant all satisfy the condition that the frequency of the electromagnetic wave is slightly higher than the cutoff frequency of the plasma, which provides guidance for the design of plasma stealth parameters.