Fundamental Theory,Device Synthesis And System Integration Of Spoof Surface Plasmon Polaritons

In mordern information societies,the rapid developments of artificial intelligence(AI)and the 5th generation wireless communication technologies stringently demand high-performance microwave devices,integrated circuits(IC)and information systems(e.g.communication,radar and imaging).The common requirements include: 1.miniaturization of devices,circuits and systems,2.outstanding signal integrity,and 3)crosstalk suppression in integrated circuits.However,for the traditional electromagnetic field and microwave technologies based on microstrips,contradictions between the above requirements and inherent disadvantages of microstrips have seriously limited the improvement of modern information systems.To overcome these contradictions,this thesis tries to find a novel kind of sub-wavelength transmission line(TL),spoof surface plasmon polariton(SSPP)TL.The basic theories,device synthesis and systematic integration based on SSPP TL are studied,which have built the theoretical and technical foundations of SSPP-based large-scale ICs and high-complexity information systems.To comprehensively introduce the concept and technologies of SSPPs,this thesis includes the following parts:1.The basic theories and analysis technologies of SSPPs.The basic theories of SSPPs are developed from their concept.The difference and relation between SSPPs and traditional slow waves are introduced as well.Based on this definition,two analysis methods for dispersion ralations aiming at different cases are proposed,including 1.a general field-network joint method to calculate the dispersion curves of complex structured surfaces with sufficient thickness;and 2.an equivalent-circuit-network method to extract the dispersion curves of ultra thin structures.Both simulations and experiments match the theoretical results very well,builting the architecture of dispersion analysis of SSPP TLs.2.Passive devices based on SSPP the structures.Based on the above dispersion analysis technologies,several SSPP TLs with obvious potentials of application are proposed,including1.SSPP TL with low dielectric loss;and 2.SSPP TL with low crosstalk.Comparing these SSPP TLs to microstrips,the merits of SSPP TLs are demonstrated.Besides,a wide-angle broadband converter from odd-mode SSPPs to spatial waves is proposed,showing the bright prospect of SSPP TLs in passive device design and synthesis.3.Active devices and systematic integration based on SSPP structures.The integration of SSPP structures with chips are studied,which produces the first reported SSPP amplifier and frequency multiplier.The compatibility of sub-wavelength SSPP and common semiconductor technology is demonstrated.Meanwhile,the concepts of SSPPs and digital coding are combined creatively,from which the reconfigurable band-pass filter,programmable SSPP devices and SSPP digital modulator have been successfully implemented,making it possible for the informatization and digitization of microwave system.More importantly,on the basis of the aforementioned active and digital technology,a wireless communication system based on SSPPs has been proposed for the first time.This system has successfully realized the over line-of-sight transmission of the sub-diffraction-limit signals,showing superior performance compared to the traditional microstrip system.