A layered fluctuation model of electron density in plasma sheath and instability effect on electromagnetic wave at Ka band

Abstract

The effects of plasma sheath on communication signals are not only power attenuation but also multiplicative noise addition because of the sheath's instability. The fluctuation properties of time-varying electron density are crucial to comprehensively understand the blackout problem. In this paper, the fluctuation laws of time-varying electron density are first comprehensively revealed in space–time–frequency domain. A layered fluctuation model of time-varying electron density is then proposed based on these fluctuation laws. The effects of dynamic plasma sheath on electromagnetic (EM) waves at Ka band are calculated by Monte Carlo quasistatic EM numerical method. Results show that the amplitude and phase of time-varying transmission coefficient both follow Gaussian distribution, whereas the spectrum curves follow a bi-Gauss function because of the effect of second mode instability in the hypersonic boundary layer. Furthermore, the means of amplitudes increase with the increasing of the incident EM wave frequency and the decreasing of the peak electron density, while the standard deviations decrease with the increasing of incident EM wave frequency, the decreasing of the peak electron density and the decreasing of electron density standard deviation.