Design And Optimization Of Filters Based On Spoof Surface Plasmon Polaritons

Spoof surface plasmon polaritons(SSPP)possess advantages such as near-field enhancement,low loss,and design flexibility,making them significantly superior to traditional microwave devices.Therefore,designing SSPP filters has become a current research hotspot.This thesis aims to design SSPP filters using a three-dimensional heterogeneous integration process,proposing design ideas that can maintain good propagation performance while reducing structural size.The first part explores the basic framework and parameters of the three-dimensional heterogeneous integration process and designs basic interconnect structures such as microstrip lines,coplanar waveguides,strip lines,and through-silicon-via for exploration.Measurement,deembedding analysis,circuit modeling,and parameter extraction processes need to be performed on the physical structures after chip packaging to better understand their performance characteristics.Further exploration and understanding of this process will provide strong support and reference for future design research.The second part aims to use the three-dimensional heterogeneous integration process to design SSPP bandpass filters.By utilizing multi-layer metal design layers,the unit structure can be folded and spiraled in space to significantly reduce the asymptotic frequency and enhance the confinement of the electromagnetic field.This innovative design method can greatly reduce the cut-off frequency and electrical size of the structure.Simulation results verify its feasibility.The third part designs the SSPP low-pass filter on a three-dimensional heterogeneous integration process.An intelligent optimization algorithm is used to optimize the design of the SSPP unit structure.The asymptotic frequency of the SSPP unit structure determines the operating frequency of the SSPP filter,and the conventional rectangular slot SSPP unit structure is optimized for the same dimensions with the objective of reducing the asymptotic frequency.The application of a particle swarm optimization algorithm is proposed for the iterative design of the unit structure,and the optimized structural unit is analyzed in comparison with the conventional unit structure to demonstrate that its asymptotic frequency is significantly reduced.Then,the transition structure is determined by analyzing the dispersion curve.Finally,the optimized SSPP filter was fabricated and tested using a standard printed circuit board(PCB)process.The experimental results verified the design idea,with the cut-off frequency of the structure being 5.4GHz,which is basically in line with the asymptotic frequency of the optimized SSPP cell structure,and the return loss in the passband being greater than17 d B and the out-of-band rejection greater than 38 d B,indicating that the structure has excellent lowpass filtering effect.In conclusion,this thesis not only realizes the design of SSPP filters through the threedimensional heterogeneous integration process but also proposes an innovative optimization method for traditional SSPP unit structures,which effectively reduces the asymptotic frequency.This approach provides new ideas and methods for design and application of SSPP filters.