The Simulation And Analysis Of OAM Antenna Based On Microstrip Patch

In recent years,vortex electromagnetic wave with orbital angular momentum(OAM)can transmit multiple signals simultaneously at the same frequency because of its spiral phase distribution in space,this means a lot to wireless communications.This feature of OAM can have a great effect and help to improve the efficiency of frequency band.As one of the major concerns,OAM has caused a great sensation in the field of wireless communication.At present,there are many methods to generate OAM,but these methods are either relatively complex in structure or costly to produce,the technical difficulty is beyond the existing production level and the physical device cannot be made.For the deficiency and defect of existing methods,in order to easily generate OAM,a method of generating OAM by microstrip patch antenna is proposed in this paper.The method is simple and compact in structure and easy to realize,better production of OAM.Firstly,the basic theory of OAM is briefly introduced based on the theoretical derivation formula.The origin and characteristics of“vortex electromagnetic wave”and“orbital angular momentum”are expounded.Secondly,the initial structure dimension(including the shape,inner and outer radius,and material of the radiation patch and the dielectric substrate),combined with a special feeding mode,of the antenna is designed.The simulation results show that,the OAM vortex electromagnetic wave with topological charge 1,2 and 3 can be generated by specific antenna structure size parameters and feed mode.The spatial radiation phase distribution,two-dimensional and three-dimensional gain patterns,S parameters,bandwidth,frequency resonance point and other important performance indexes are analyzed for all the results.and the influence of antenna size parameters on antenna performance is analyzed through the Parametrics(parameter scanning)function of HFSS.Finally,on the basis of the original OAM antenna model with specific topological charge,the structure size and feed mode of the antenna are further improved,and then the simulation experiment is carried out to see what changes the main performance indexes of the antenna are,and summarize the rules.In the course of the simulation experiment,the full wave 3D electromagnetic simulation software Ansoft HFSS,which is developed by Ansoft Company,is used.In this paper,the antenna structure size and feed mode which can generate OAM are deduced theoretically,and then the simulation results show that the design of this paper can generate OAM with different topological charges.