Analysis Of Electromagnetic Field Propagation In The Presence Of Four-layered Region And Its Application To Antennas Design

In recent years,with the electromagnetic propagation problem in layered media,which has important applications in many fields such as geological exploration,seabed detection,submarine communication and microstrip circuits,people's theoretical understanding of this problem is getting deeper and deeper.With the introduction of the concept of adsorbing surface waves,the theoretical study of three-layer structure has been widely used.However,there are some differences in the academic world for the study of four-layer structure.Therefore,based on the planar four-layer model,the theoretical results of the electromagnetic field excited by vertical electric dipole are studied,and a package antenna based on three-layer dielectric structure is designed.The main research work is summarized as follows:Firstly,the research background and application of the analytical solution of electromagnetic field expression in four-layer medium are introduced.The analytical results of electromagnetic field in four-layer medium are studied.The surface of the covered sewer is modeled and analyzed by electromagnetic field,in conclusion.It is worth noting that the frequency domain solutions of direct wave,ideal reflected wave,side wave,and adsorbed surface wave are given in this paper,and the numerical calculation results of far field are given.Finally,this paper compares the results obtained by the above process with the propagation characteristics of common models,analyzes the differences between them,and gives a possible explanation for the controversy in the academic world.Secondly,on the basis of the solution of the four-layer dielectric electromagnetic wave,the theoretical derivation of the field-element equivalent to the electric dipole superposition is given for the propagation problem of the antenna,and the electromagnetic wave excited by the unit electric dipole is given.Spatial distribution in the air layer of a four-layer dielectric model.The analysis method of the line antenna was studied to pave the way for the antenna design of the third part.Third,a packaged antenna based on three layers of media was designed.In this paper,the input impedance of the interface between the outer layer and the three-layer dielectric package antenna is derived for the designed antenna physical model,and the calculation results are given.In the last part,the main research contents of the thesis are briefly described,and the inadequacies of the research in this paper are further pointed out.At the same time,the research work that can be carried out later is made a certain prospect.