Research On Resonators And Filters Based On Effective Localized Surface Plasmons

Effective Localized Surface Plasmons(ELSPs)induced by structural dispersion are a localized electromagnetic mode with large field confinement and high field enhancement.ELSPs exhibit multipolar resonant characteristics and can mimick optical localized surface plasmons at microwave and terahertz frequencies perfectly.In this thesis,based on the basic characteristics of ELSPs,we carried out theoretical and application research on ELSPs resonators and filters,which are expected to be applied in the miniaturization design of microwave resonators and filters.The main contents include the following aspects:1.We investigate the effect of the metal wires number on the resonance mode numbers of ELSPs,and the sensitivity of ELSPs resonance to the incident wave incidence and polarization angles,Specifically,we study the resonance characteristics of four ELSPs resonator models with two end walls being PEC-PEC,PMC-PMC,PEC-PMC and metal wire number being 2 to 8.In addition,we study variations of the mode numbers and resonance frequencies and intensity with the change of the incidence and polarization angles.Finally,we experimentally verify the above mode number tenability of the ELSPs resonators.2.A cavity band-pass filter based on ELSPs resonator is designed and studies.This band-pass filter utilize the two orthogonal modes of the ELSPs resonator to realize a single-cavity dual-modes filter and a dual-cavity four-modes band-pass filter respectively.To reduce the metal loss and increase the band separation between the main mode and the first higher mode,the number of metal wires of the ELSPs resonator was reduced to 4,and the length of metal wires was adjusted.A single-cavity dual-modes ELSPs bandpass filter with good out-of-band suppression is realized.3.We propose a simplified planar ELSPs resonator model.which is composed of a cuboid dielectric block with two metal strips printed on both sides.The metal wall can be realized by metal via.A third-order bandpass filter based on planar ELSPs resonator is designed,simulated and experimentally verified.This work combine the high Q features of dielectric filter and the high integration characteristics of the PCB circuits,providing a new platform for the design of the high performance planar miniaturized filter.