Application Of HIE-FDTD High Perfomance Parallel Computing Method For The Design Of Multi-Pass Band Frequency Selective Structures

As a spatial filter,frequency selective surface(FSS)is often a planar periodic structure with filtering characteristics for the incident electromagnetic wave.Due to its wide requirements for both military and civil fields,different FSS structures have been proposed operating at microwave,millimeter wave,infrared and other frequency bands.The main research and academic contribution of this thesis are summarized as follows.(1)Traditional Finite-Difference-Time-Domain(FDTD)method is introduced at first,and further,it is improved as a hybrid implicit-explicit FDTD,i.e.HIE-FDTD,with its properties and implemented for simulation described.(2)By applying the Floquet theorem and periodic boundary condition,the transmission characteristics of an entire FSS array can be obtained through simulating single FSS unit.Aiming at the grating effect of FSS,the research on how to suppress the grating lobes is carried out.The effects of different factors on the performance of FSS are further examined,such as the size of FSS cell,the period and arrangement of cell array,the thickness and dielectric constant of dielectric substrate,the layer number of FSS,the angle of incident wave and its polarization state.Further,three FSSs are designed with single and double passbands,respectively,and they are fabricated and measured for certain electromagnetic protection of antennas,where good agreements are obtained between the simulated and measured transmission coefficients.(3)HIE-FDTD-based massive parallel computing program is developed based on high performance parallel computing framework JASMIN,it is highly scalable and can perform simulation on high-performance computers with ten of thousands CPUs used.The differences in frequency selection characteristics between the finite-scale and infinite periodic FSS arrays are demonstrated based on numerical experiments.Finaly,HIE-FDTD program is successfully used for the design of multi-based graphene FSS operating at THz bands,and it is further demonstrated the capability of the developed algorithmon.