等离子鞘套热力学波动对电磁波传播的影响

Thermodynamic Fluctuation Effects of Plasma Sheath on Electromagnetic Wave Propagation

针对等离子鞘套热力学波动造成电磁波传播特性变化的问题,结合湍流理论、等离子理论和电磁波传播理论,得到了热力学参数波动与介电常数间的关系。计算了不同状态下热力学参数波动引起S和Ka波段电磁波透射和反射系数的变化。结果表明,当电子密度增大,S波段反射系数变化减小、透射系数变化增大;当Ka波段在碰撞频率10MHz时,反射系数变化增大、透射系数变化减小,在碰撞频率1GHz和50GHz时透射系数变化反射系数变化先增后减。不同高度下波动的影响也不同,S波段透射和反射系数变化随高度升高先减后增;Ka波段透射系数变化先减后增、反射系数变化先减后增而后再次减小。因此,应根据实际环境状态获得波动的包络范围,进而针对性开展测控通信系统设计。

The thermodynamic parameter fluctuation of plasma sheath could change the transmission and reflection coefficients.This paper deduces the relation between the thermodynamic parameter fluctuation of plasma sheath and the transmission and reflection coefficients.On this basis,the changes of the transmission and reflection coefficients at S and Ka bands are simulated.The results show that,when the electron density increases,the change of the reflection coefficient decreases and the change of the transmission coefficient increases,at S band.At Ka band,when the collision frequency is10 MHz,the change of the reflection coefficient increases and the change of the transmission coefficient decreases;while when the collision frequency is 1 GHz and 50 GHz,the change of the reflection coefficient increases and the change of the transmission coefficient increases first and decreases later.Besides,the effects vary with the altitudes.The changes decrease first and increase later at S band.At Ka band,the change of the transmission coefficient decreases first and increases later,while the change of the reflection coefficient experiences a decrease-increase-decrease tendency.The effects are different in diverse plasma situations.Thus it is proposed that the TT&C system should be well-designed aiming at specific plasma environment.