Research On Complex Dielectric Coefficient And Attenuation Characteristics In Space Dusty Plasma

Due to the distribution of various particles in the space dust plasma,the dielectric coefficient value is changed and the attenuation of electromagnetic waves also has a greater change in the space dust plasma.In this paper,the dust plasma model of CST is used to study the attenuation characteristics of electromagnetic wave in the dust plasma,and the phenomenon of black obstacle is preliminary studied.The complex permittivity has an extremely important influence on the return loss by three observations.They are Polar mesosphere summer echoes(PMSE),the absorption phenomenon of D layer space and ECT02 data.In the simulation of the periodic structure,the increment structure and the decrement structure,it shows that the change of the imaginary part of the complex permittivity has an important effect on the return loss of the electromagnetic wave in the dust plasma.The main contents of this paper are as follows:1?We introduce the basic knowledge of space dust plasma,such as the definition of dust plasma,collision frequency and so on.Then,we show the black barrier phenomenon,the normal and abnormal absorption phenomena of D layer,and PMSE.The normal and abnormal absorption phenomena of D layer study the different of electron density with height at VHF and UHF on July 12,2007.2?The simulation model of electromagnetic wave is established by CST.First,the uniform and non-uniform dust plasma model is established.We study the attenuation of the incident electromagnetic in the simulation model.The propagation of electromagnetic wave is difficult with the increment of electron density in the dust plasma;the attenuation of electromagnetic wave is less with the increment of frequency.Then,the uniform and non-uniform cone dust plasma model is established.The attenuation of electromagnetic wave is studied with the change of the incident angle of electromagnetic wave in the dust plasma model.Due to the irregular of the designed model,the attenuation of the electromagnetic wave fluctuates in the low frequency band.3?The changes of the dust plasma density are observed with the radar between 82 km and 90 km.The changes of the complex permittivity values are deduced in the dust plasma.The range of height is divided into 36 layers for the calculation of return lossat 50 MHz to 1300 MHz.It is shown that the return loss of TM is 60 dB to 200 dB(the vaule of most return loss is 60 dB to 160 dB)between 50 MHz and 1300 MHz.In the layered simulation,the influences of reflection coefficient and transmission coefficient of TM and TE wave are discussed with the angle variation of the incident electromagnetic wave.Then,the return loss of TM and TE is studied with the vertical incident dust plasma layer in periodic structure,incremental structure and decremented structure.It shows that the changes of the imaginary part of the complex dielectric are10% and the changes of the imaginary part of the complex dielectric of layers are 1%;the variation of the return loss is more than 20dB.