基于不同边界条件的SIW谐振腔导模场分析及应用

总结了完备的六种不同边界条件的基片集成波导(SIW)谐振腔结构体系.基于镜像原理和亥姆霍兹方程,给出而不同边界条件下SIW谐振腔的导模场的闭式解.分析了所有边界条件下的谐振腔的场分布,与全波仿真分析、传输线模型法和空腔模型理论给出的结果一致.给出了各种边界条件下SIW谐振腔的谐振频率计算公式.基于提出的传输线附加额外的两个边界条件与谐振腔等效的原理,分析了在SIW谐振腔内,TE模、TM模与TEM模的共存机理.阐述了不同边界条件下的SIW谐振腔的演变关系.最后设计了基于不同边界条件的SIW谐振腔结构的双模带通滤波器和均衡器,该滤波器的两个模式,TE100(TEM模式)和TE102独立可调.器件的实测结果与仿真结果一致,验证了理论分析的正确性,为微波器件的小型化设计提供了思路.

Guided-Mode Field Analysis of SIW Resonator with Different Boundary Conditions and Its Applications

All the substrate integrated waveguide (SIW) resonant cavities with six different boundary conditions are summarized and analyzed totally.Based on the mirror image principle and Helmholtz equations,the closed form solutions of the guided mode field of the SIW resonant cavities under different boundary conditions are given.The field distributions of the resonant cavities under all the boundary conditions are analyzed,and the results are consistent with the results given by the full wave simulation analysis,transmission line model method and empty cavity model method.The formulas for calculating the resonant frequencies of the resonant cavities under various boundary conditions are presented.Based on the proposed theory that the transmission line added extra two boundary conditions is equivalent to the resonant cavity,the coexistence mechanism of TE mode,TM mode and TEM mode is analyzed.This paper describes the evolution of the SIW resonant cavities under different boundary conditions as well.Finally,a dual-mode SIW bandpass filter and a SIW equalizer,based on different boundary conditions are designed,fabricated and measured to demonstrate the proposed method.Two modes of the filter,TE100 (or TEM mode) and TE102 can be tuned independent and the measured results are in agreement with the simulation results.The relevant research results provide ways for the miniaturization design of microwave devices.