Analysis Of Electromagnetic Characteristics Of Frequency Selective Radome

Frequency-selective radome refers to the radome with frequency-selective capability.It usually consists of a frequency selective surface(Frequency Selective Surface,FSS)attached to the dielectric surface of the radome or as a sandwich between different dielectrics.Because FSS only resonates with electromagnetic wave at a specific frequency,it can effectively filter out the signals in useless frequency band and retain the useful ones at both the transmitter and the receiver.This not only enhances the adaptability of signal transceiver to different application scenarios,but also reduces the risk of interference and damage from high-power signals.Therefore,FSS is widely used in various electromagnetic environments.When the radome is added to the frequency selective surface,it not only plays the fundamental role of protecting the antenna,but also improves the electromagnetic stability of the antenna.It is very important to study the electromagnetic characteristics of frequency selective radome for the design and application of antenna itself.At present,however,the simulation of FSS is mostly at the unit,plane and independent level.The coupling between elements,the deformation of radome surface and the influence of radome medium on the frequency selectivity of FSS are not fully taken into account.Therefore,this article starts from two aspects.Firstly,aiming at the problem that the large number of small structures in the frequency selective radome makes it difficult to model in the early stage and to fine-tune in the later stage,this paper realizes the integrated rapid modeling of the radome and FSS by compiling programs to create geometric information files.Secondly,after modeling and meshing,the electromagnetic characteristics of frequency selective radomes,such as radar cross section(Radar Cross Section,RCS)and antenna gain,are calculated.The results are analyzed to verify the frequency selection effect of the radome.The geometric model established in this paper is strictly composed of planar quadrilateral interconnections.Among the algorithms that can be used in later calculation,the high-order method of moments(Higher Order Method of Moments,HO-Mo M)needs quadrilateral meshes as integral elements,and the multilevel fast multipole algorithm(Multilevel Fast Multipole Method,MLFMA)needs triangular meshes,which can be easily obtained by splitting quadrilateral meshes.Therefore,the direct establishment of quadrilateral-based element model can greatly simplify the latter mesh generation,ensure the quality of the mesh,and reduce the possibility of program collapse or calculation errors caused by deformed meshes.The electromagnetic calculation method adopted in this paper has the characteristics of high calculation accuracy and large calculation scale.It is suitable for the complex model of frequency selective radome,which has a large number of elements.In this paper,an integrated modeling scheme based on this model is proposed,which effectively realizes the rapid creation and setting of radome and frequency selective surface.In this paper,three kinds of frequency selective radomes are presented and two of them are calculated in detail.The results of calculation are analyzed and compared,which shows the validity of the modeling method in this paper.