设计了一种工作于X波段的基于共享孔径Fabry-Perot(F-P)谐振腔结构的宽带高增益磁电偶极子微带天线,并设计了三种不同尺寸的双层频率选择表面(FSS)单元,通过共享孔径布阵组成了超材料覆层.利用三种FSS单元的相位补偿特性,有效拓展了覆...设计了一种工作于X波段的基于共享孔径Fabry-Perot(F-P)谐振腔结构的宽带高增益磁电偶极子微带天线,并设计了三种不同尺寸的双层频率选择表面(FSS)单元,通过共享孔径布阵组成了超材料覆层.利用三种FSS单元的相位补偿特性,有效拓展了覆层天线的增益带宽.实测和仿真结果均表明,加载超材料覆层后,磁电偶极子天线在7.8—12.3 GHz内S_(11)<-10 d B,相对带宽达到44.7%,覆盖整个X波段.天线增益在7.9—12.1 GHz内均有明显的提高,最大提高了7 d B.相较于传统的F-P谐振腔结构覆层天线,设计的基于共享孔径的F-P谐振型超材料覆层天线能够明显拓展天线增益带宽,在新型宽带高增益天线设计方面具有广阔的应用前景.展开更多
Fabry-Perot(F-P)谐振腔天线通常易实现高增益,但由于口径场非均匀的电磁场分布,使得其在大口径尺寸下的口径效率较低。本文设计了一种新型的F-P谐振腔天线,该天线采用非均匀特异媒质覆盖层实现口径场等幅分布,并通过非均匀特异媒质反...Fabry-Perot(F-P)谐振腔天线通常易实现高增益,但由于口径场非均匀的电磁场分布,使得其在大口径尺寸下的口径效率较低。本文设计了一种新型的F-P谐振腔天线,该天线采用非均匀特异媒质覆盖层实现口径场等幅分布,并通过非均匀特异媒质反射地实现口径场同相分布,从而提升F-P谐振腔天线在大口径尺寸下的口径效率。基于射线追踪法,推导了非均匀覆盖层和非均匀反射地的设计公式。本文设计、加工并测试了一款口径尺寸为5.18λ(λ为自由空间波长)的圆形F-P谐振腔天线。仿真和测试结果吻合良好,|S11|<-10 d B的阻抗带宽为4.14%(5.740~5.980 GHz);在工作频点5.8 GHz处,该新型F-P谐振腔天线的增益为23.8 d Bi,与传统F-P谐振腔天线相比,其口径效率从78.9%提高到90.5%。展开更多
Fabry–Perot(FP)modes are a class of fundamental resonances in photonic crystal(PhC)slabs.Owing to their low quality factors,FP modes are frequently considered as background fields with their resonance nature being ne...Fabry–Perot(FP)modes are a class of fundamental resonances in photonic crystal(PhC)slabs.Owing to their low quality factors,FP modes are frequently considered as background fields with their resonance nature being neglected.Nevertheless,FP modes can play important roles in some phenomena,as exemplified by their coupling with guided resonance(GR)modes to achieve bound states in the continuum(BIC).Here,we further demonstrate the genuine resonance mode capability of FP modes PhC slabs.Firstly,we utilize temporal coupled-mode theory to obtain the transmittance of a PhC slab based on the FP modes.Secondly,we construct exceptional points(EPs)in both momentum and parameter spaces through the coupling of FP and GR modes.Furthermore,we identify a Fermi arc connecting two EPs and discuss the far-field polarization topology.This work elucidates that the widespread FPs in PhC slabs can serve as genuine resonant modes,facilitating the realization of desired functionalities through mode coupling.展开更多
文摘设计了一种工作于X波段的基于共享孔径Fabry-Perot(F-P)谐振腔结构的宽带高增益磁电偶极子微带天线,并设计了三种不同尺寸的双层频率选择表面(FSS)单元,通过共享孔径布阵组成了超材料覆层.利用三种FSS单元的相位补偿特性,有效拓展了覆层天线的增益带宽.实测和仿真结果均表明,加载超材料覆层后,磁电偶极子天线在7.8—12.3 GHz内S_(11)<-10 d B,相对带宽达到44.7%,覆盖整个X波段.天线增益在7.9—12.1 GHz内均有明显的提高,最大提高了7 d B.相较于传统的F-P谐振腔结构覆层天线,设计的基于共享孔径的F-P谐振型超材料覆层天线能够明显拓展天线增益带宽,在新型宽带高增益天线设计方面具有广阔的应用前景.
文摘Fabry-Perot(F-P)谐振腔天线通常易实现高增益,但由于口径场非均匀的电磁场分布,使得其在大口径尺寸下的口径效率较低。本文设计了一种新型的F-P谐振腔天线,该天线采用非均匀特异媒质覆盖层实现口径场等幅分布,并通过非均匀特异媒质反射地实现口径场同相分布,从而提升F-P谐振腔天线在大口径尺寸下的口径效率。基于射线追踪法,推导了非均匀覆盖层和非均匀反射地的设计公式。本文设计、加工并测试了一款口径尺寸为5.18λ(λ为自由空间波长)的圆形F-P谐振腔天线。仿真和测试结果吻合良好,|S11|<-10 d B的阻抗带宽为4.14%(5.740~5.980 GHz);在工作频点5.8 GHz处,该新型F-P谐振腔天线的增益为23.8 d Bi,与传统F-P谐振腔天线相比,其口径效率从78.9%提高到90.5%。
基金Project supported by the National Natural Science Foundation of China (Grant Nos.12074049 and 12347101)。
文摘Fabry–Perot(FP)modes are a class of fundamental resonances in photonic crystal(PhC)slabs.Owing to their low quality factors,FP modes are frequently considered as background fields with their resonance nature being neglected.Nevertheless,FP modes can play important roles in some phenomena,as exemplified by their coupling with guided resonance(GR)modes to achieve bound states in the continuum(BIC).Here,we further demonstrate the genuine resonance mode capability of FP modes PhC slabs.Firstly,we utilize temporal coupled-mode theory to obtain the transmittance of a PhC slab based on the FP modes.Secondly,we construct exceptional points(EPs)in both momentum and parameter spaces through the coupling of FP and GR modes.Furthermore,we identify a Fermi arc connecting two EPs and discuss the far-field polarization topology.This work elucidates that the widespread FPs in PhC slabs can serve as genuine resonant modes,facilitating the realization of desired functionalities through mode coupling.
