电磁波在非均匀碰撞等离子体中的透射增强效应

为研究碰撞等离子体对电磁波传输性质的影响，基于电磁波在介质中的传输特性，将等离子体作为一种特殊的介质，针对一定实验条件下的高功率微波（HPM）大气等离子体与一定范围电磁波的透射特性开展了实验、理论及仿真研究。研究发现：S波段HPM在50 Pa真空下形成的等离子体对不同频率的电磁波透射特性具有较大影响，且在一定频率范围内有规律地出现电磁波透射信号增强效应现象；获取了一系列不同频率连续电磁波穿过HPM等离子体区域的透射波形，并对波形进行了归一化处理，在32.4 GHz下，连续电磁波穿过有无等离子体区域的透射系数约有2倍的差异。建立了仿真模型，获得31.5～32.5 GHz范围内透射系数分布曲线图，穿过等离子体的电磁波出现透射增强效应，且在某些频点上出现了约1.9倍的透射增强。该研究成果为HPM大气等离子体在隐身、应急通讯、黑障通讯等方面的应用提供了重要的技术支撑。

Transmission enhancement effect of electromagnetic wave in non-uniform collisional plasma

The effect of plasma on the transmission properties of electromagnetic waves and its application have always been one of the key research directions of electromagnetic theory and technology and plasma physics. The enhancement effect of collisional plasma on electromagnetic waves is a classic subject of the interaction between electromagnetic waves and plasma. Based on the transmission characteristics of electromagnetic waves in medium, this paper takes plasma as a special medium, and carries out experimental, theoretical and simulation studies on the transmission characteristics of high power microwave (HPM) atmospheric plasma and a certain range of electromagnetic waves under certain experimental conditions. The study found that the plasma formed by the S-band HPM under a vacuum of 50 Pa has a great influence on the electromagnetic wave transmission characteristics of different frequencies, and the electromagnetic wave transmission signal enhancement effect occurs regularly within a certain frequency range. A series of transmission waveforms of continuous electromagnetic waves of different frequencies passing through the HPM plasma area were obtained, and the waveforms were normalized. At 32.4 GHz, the transmission coefficient of continuous electromagnetic waves passing through the plasma area with plasma is about twice as high as that through the area without plasma. A simulation model was established, and the transmission coefficient distribution curve in the range of 31.5−32.5 GHz was obtained. The electromagnetic wave passing through the plasma showed a transmission enhancement effect, and at some frequency points, there was a transmission enhancement of about 1.9 times. The research results provides important technical support for the application of plasma in stealth, emergency communications, and black barrier communications.