Research On Millimeter Wave Propagation Attenuation Based On Equivalent Dielectric Constant

With the application of millimeter wave in many fields such as communication and manufacturing,the corresponding study on millimeter wave has attracted much attention from researchers.With the continuous emergence of new materials,especially the extensive use of mixed materials,how to determine the physical properties of new materials in millimeter wave propagation has become a very difficult problem for engineers.On the other hand,in complex scenes,accurate calculation of millimeter waves' attenuation during propagation,which is helpful to avoid signal fading,is another application problem of millimeter wave.Aiming at the above two points,this paper proposes a model for deducing the equivalent dielectric constant of the mixture under millimeter wave conditions.Based on the traditional equivalent dielectric constant model,the mixture is regarded as a whole,and the calculation of the mixture's dielectric constant at high frequency is derived by analog circuit.For the derived model,the dielectric constants of a series of mixtures are measured by building a terahertz time-domain spectroscopy system.The measurement results are compared with the model's calculations,and the reason for the error between the theoretical calculation results and the actual measurement results is analyzed,indicating that the model is practical and accurate.On the other hand,this paper deduces the attenuation model of millimeter wave under the weather of cloud,fog,rain,sand and dust according to the propagation characteristics of millimeter wave.This thesis explains the cause of attenuation and the calculation of attenuation theoretically.This thesis compares the derivation model,authoritative classic model with the actual measured millimeter wave attenuation value and analyzes the difference and accuracy of the calculation results between the models under different conditions.In addition,the proposed method reduces the parameters needed to derive the model without loss of much accuracy.Finally,the analysis of the errors between all models and the measurement results shows that the derived attenuation model can calculate the attenuation value of millimeter wave propagation well and can be applied to the real-life scenarios.