Terahertz polarization conversion devices have significant potential applications in various fields such as terahertzimaging and spectroscopy.In this paper,we utilize genetic algorithms to topologically optimize the m...Terahertz polarization conversion devices have significant potential applications in various fields such as terahertzimaging and spectroscopy.In this paper,we utilize genetic algorithms to topologically optimize the metasurface unit cellsand design a reflective linear polarization conversion metasurface with ultra-broadband and wide-angle characteristics.By partitioning the metallic pattern layer into quadrants,the encoding length is effectively reduced,resulting in a shorteroptimization time.The research results indicate that the converter possesses a polarization conversion efficiency ratio higherthan 90%and a relative bandwidth ratio of 125%in a range of 0.231-0.995 THz.Meanwhile,it can maintain excellentpolarization conversion properties when the incident angle of terahertz waves is less than 45°and the polarization angle isless than 15°,demonstrating excellent practicality.New insights are provided for the design of terahertz wide-angle ultrawidebandpolarization conversion devices,and the proposed metasurfce has potential applications in terahertz polarizationimaging,spectroscopy and communication fields.展开更多
An ultra-broadband perfect absorber consisting of cascaded nanodisk arrays is demonstrated by placing insulatormetal-insulator-metal nanodisks on insulator-metal film stacks.The absorber shows over 90% absorption in a...An ultra-broadband perfect absorber consisting of cascaded nanodisk arrays is demonstrated by placing insulatormetal-insulator-metal nanodisks on insulator-metal film stacks.The absorber shows over 90% absorption in a wavelength range between 600 nm and 4000 nm under transverse magnetic(TM) polarization,with an average absorptivity of 91.5%and a relative absorption bandwidth of 147.8%.The analysis of the electric field and magnetic field show that the synergy of localized surface plasmons,propagating surface plasmons,and plasmonic resonant cavity modes leads to the ultrabroadband perfect absorption,which accords well with the results of impedance-matched analysis.The influences of structural parameters and different metal materials on absorption performance are discussed.Furthermore,the absorber is polarization-independent,and the absorption remains more than 90% at a wide incident angle up to 400 under TE polarization and TM polarization.The designed ultra-broadband absorber has promising prospects in photoelectric detection and imaging.展开更多
The optical window of low-observable platform needs to be compatible with ultra-broadband absorption,hence an optically-transparent absorber with ultra-broadband absorption is designed and analyzed in this paper.The t...The optical window of low-observable platform needs to be compatible with ultra-broadband absorption,hence an optically-transparent absorber with ultra-broadband absorption is designed and analyzed in this paper.The transparent materials indium-tin-oxide(ITO)film and polymethylmethacrylate(PMMA)are selected as the lossy layer and the supporting dielectric layer,respectively.The optically-transparent ultra-broadband absorber(OT-UBA)is composed of three layers of ITO square patterns,three layers of PMMA dielectric and a uniform ITO plane.The ITO square patterns can realize arbitrary equivalent series of RC(resistor and capacitor)circuit,so that three layers of ITO square patterns together with the ITO plane can achieve ultra-broadband absorption based on the equivalent circuit optimization.Measured results shows that the 90%-absorption bandwidth covers 2-17 GHz while the light transmittance achieves 59.6%with a total thickness of only 12.9 mm.展开更多
We propose an ultra-broadband and polarization independent planar absorber comprising multilayered graphene. The bandwidth of the proposed absorber is extended by increasing the number of layers of graphene, and it is...We propose an ultra-broadband and polarization independent planar absorber comprising multilayered graphene. The bandwidth of the proposed absorber is extended by increasing the number of layers of graphene, and it is polarization independent due to its symmetrical unit structure. The full wave simulation results show that an absorber with three graphenebased layers can efficiently harvest an electromagnetic wave with random polarization from 17.9 GHz to 188.7 GHz（i.e.,covering frequency regimes from K to D bands and relative bandwidth of - 165%）. The physical absorption mechanism of ultra-broadband absorption has been elaborated upon using the destructive interference method and multiple resonances approach in a multilayered medium. The proposed absorber can be used in many applications such as medical treatment,electromagnetic compatibility, and stealth technique.展开更多
In this paper, we present a novel metasurface design that achieves a high-efficiency ultra-broadband cross polarization conversion. The metasurface is composed of an array of unit resonators, each of which combines an...In this paper, we present a novel metasurface design that achieves a high-efficiency ultra-broadband cross polarization conversion. The metasurface is composed of an array of unit resonators, each of which combines an H-shaped structure and two rectangular metallic patches. Different plasmon resonance modes are excited in unit resonators and allow the polarization states to be manipulated. The bandwidth of the cross polarization converter is 82% of the central frequency,covering the range from 15.7 GHz to 37.5 GHz. The conversion efficiency of the innovative new design is higher than 90%.At 14.43 GHz and 40.95 GHz, the linearly polarized incident wave is converted into a circularly polarized wave.展开更多
Based on the designed As2Se3 and As2S3 chalcogenide glass photonic crystal fiber（PCF） and the scalar nonlinear Schrdinger equation,the effects of pump power and wavelength on modulation instability（MI） gain are co...Based on the designed As2Se3 and As2S3 chalcogenide glass photonic crystal fiber（PCF） and the scalar nonlinear Schrdinger equation,the effects of pump power and wavelength on modulation instability（MI） gain are comprehensively studied in the abnormal dispersion regime of chalcogenide glass PCF.Owing to high Raman effect and high nonlinearity,ultra-broadband MI gain is obtained in chalcogenide glass PCF.By choosing the appropriate pump parameter,the MI gain bandwidth reaches 2738 nm for the As2Se3 glass PCF in the abnormal-dispersion region,while it is 1961 nm for the As2S3 glass PCF.展开更多
The numerical simulations and experimental results of an ultra-broadband acoustic ventilation barrier composed of periodic unit cells are reported in this paper.Based on multiple mechanisms,including sound absorption ...The numerical simulations and experimental results of an ultra-broadband acoustic ventilation barrier composed of periodic unit cells are reported in this paper.Based on multiple mechanisms,including sound absorption by eigenmodes of the unit cell and sound reflection by a plate structure on upper surface of the unit cell,a single-layer ventilation barrier with broadband sound reduction is designed,and its working bandwidth can reach about 1560 Hz.The experimental results accord well with the simulation results.Furthermore,two types of three-layer ventilation barriers are designed and demonstrated by using the unit cells with different values of a(the length of the hollow square region)and w(the width of the channel between the adjacent cavities),and the bandwidths of both ventilation barriers can increase to 3160 Hz and 3230 Hz,respectively.The designed barrier structures have the advantages of ultra-broadband sound reduction and ventilation,which paves the way to designing high-performance ventilation barriers for the applications in environmental protection and architectural acoustics.展开更多
为满足毫米波通信等应用领域对超宽带功率放大器的需求,文章采用南京电子器件研究所50 nm GaN HEMT工艺研制了一款覆盖W、F波段的超宽带功率放大器。首先,使用模型对实验数据进行拟合外推,得到宽带范围内管芯的功率阻抗;其次,采用LC结...为满足毫米波通信等应用领域对超宽带功率放大器的需求,文章采用南京电子器件研究所50 nm GaN HEMT工艺研制了一款覆盖W、F波段的超宽带功率放大器。首先,使用模型对实验数据进行拟合外推,得到宽带范围内管芯的功率阻抗;其次,采用LC结构加高低阻抗微带线方式进行宽带电路匹配,并设计了末级、级间和输入级的匹配电路拓扑结构;最后,对级间匹配电路进行综合优化调整,并采用兰格桥进行功率合成。最终,放大器在80GHz~140GHz范围内,典型线性增益达18dB,饱和输出功率达100mW,同时,在全频段范围内,芯片具有±1dB的功率平坦度和良好的回波损耗,在太赫兹领域具有广阔的应用前景。展开更多
为更好地使URLLC(Ultra-Reliable and Low Latency Communications)与增强型移动宽带业务(eMBB:enhanced Mobile Broad Band)在同一载波频段有效复用,进一步提升混合业务系统性能,提出一种基于可扩展传输时间间隔(TTI:Transmission Time...为更好地使URLLC(Ultra-Reliable and Low Latency Communications)与增强型移动宽带业务(eMBB:enhanced Mobile Broad Band)在同一载波频段有效复用,进一步提升混合业务系统性能,提出一种基于可扩展传输时间间隔(TTI:Transmission Time Interval)的动态带宽分配策略。系统根据业务类型进行带宽动态划分;时域上提升URLLC调度优先级;频域上采用不同长度的TTI进行以用户为中心的无线资源分配。动态系统级仿真表明,在不同程度的负载水平下,相比传统无线资源分配算法,该方案能在有效满足URLLC用户时延需求的前提下优化eMBB用户的吞吐量消耗,URLLC用户时延增益最高达到83.8%,提升了5G混合业务系统中不同类型业务的服务质量(QoS:Quality of Service)。展开更多
基金supported by the National Natural Science Foundation of China and the Open Project Program of Wuhan National Laboratory for Optoelectronics(Grant No.2022WNLOKF012).
文摘Terahertz polarization conversion devices have significant potential applications in various fields such as terahertzimaging and spectroscopy.In this paper,we utilize genetic algorithms to topologically optimize the metasurface unit cellsand design a reflective linear polarization conversion metasurface with ultra-broadband and wide-angle characteristics.By partitioning the metallic pattern layer into quadrants,the encoding length is effectively reduced,resulting in a shorteroptimization time.The research results indicate that the converter possesses a polarization conversion efficiency ratio higherthan 90%and a relative bandwidth ratio of 125%in a range of 0.231-0.995 THz.Meanwhile,it can maintain excellentpolarization conversion properties when the incident angle of terahertz waves is less than 45°and the polarization angle isless than 15°,demonstrating excellent practicality.New insights are provided for the design of terahertz wide-angle ultrawidebandpolarization conversion devices,and the proposed metasurfce has potential applications in terahertz polarizationimaging,spectroscopy and communication fields.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61775140 and 62005165)。
文摘An ultra-broadband perfect absorber consisting of cascaded nanodisk arrays is demonstrated by placing insulatormetal-insulator-metal nanodisks on insulator-metal film stacks.The absorber shows over 90% absorption in a wavelength range between 600 nm and 4000 nm under transverse magnetic(TM) polarization,with an average absorptivity of 91.5%and a relative absorption bandwidth of 147.8%.The analysis of the electric field and magnetic field show that the synergy of localized surface plasmons,propagating surface plasmons,and plasmonic resonant cavity modes leads to the ultrabroadband perfect absorption,which accords well with the results of impedance-matched analysis.The influences of structural parameters and different metal materials on absorption performance are discussed.Furthermore,the absorber is polarization-independent,and the absorption remains more than 90% at a wide incident angle up to 400 under TE polarization and TM polarization.The designed ultra-broadband absorber has promising prospects in photoelectric detection and imaging.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61901492 and 61901493)Provincial Natural Science Foundation of Hunan(Grant No.2022JJ30665)。
文摘The optical window of low-observable platform needs to be compatible with ultra-broadband absorption,hence an optically-transparent absorber with ultra-broadband absorption is designed and analyzed in this paper.The transparent materials indium-tin-oxide(ITO)film and polymethylmethacrylate(PMMA)are selected as the lossy layer and the supporting dielectric layer,respectively.The optically-transparent ultra-broadband absorber(OT-UBA)is composed of three layers of ITO square patterns,three layers of PMMA dielectric and a uniform ITO plane.The ITO square patterns can realize arbitrary equivalent series of RC(resistor and capacitor)circuit,so that three layers of ITO square patterns together with the ITO plane can achieve ultra-broadband absorption based on the equivalent circuit optimization.Measured results shows that the 90%-absorption bandwidth covers 2-17 GHz while the light transmittance achieves 59.6%with a total thickness of only 12.9 mm.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61661012,61461016,61361005,and 61561013)the Natural Science Foundation of Guangxi,China(Grant No.2017JJB160028)+1 种基金the Program for Innovation Research Team of Guilin University of Electronic Technology,Chinathe Dean Project of Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing,China
文摘We propose an ultra-broadband and polarization independent planar absorber comprising multilayered graphene. The bandwidth of the proposed absorber is extended by increasing the number of layers of graphene, and it is polarization independent due to its symmetrical unit structure. The full wave simulation results show that an absorber with three graphenebased layers can efficiently harvest an electromagnetic wave with random polarization from 17.9 GHz to 188.7 GHz（i.e.,covering frequency regimes from K to D bands and relative bandwidth of - 165%）. The physical absorption mechanism of ultra-broadband absorption has been elaborated upon using the destructive interference method and multiple resonances approach in a multilayered medium. The proposed absorber can be used in many applications such as medical treatment,electromagnetic compatibility, and stealth technique.
基金supported by the National Natural Science Foundation of China(Grant Nos.61471292,61331005,61471388,51277012,41404095,and 61501365)the 111 Project,China(Grant No.B14040)+1 种基金the National Basic Research Program of China(Grant No.2015CB654602)the China Postdoctoral Science Foundation(Grant No.2015M580849)
文摘In this paper, we present a novel metasurface design that achieves a high-efficiency ultra-broadband cross polarization conversion. The metasurface is composed of an array of unit resonators, each of which combines an H-shaped structure and two rectangular metallic patches. Different plasmon resonance modes are excited in unit resonators and allow the polarization states to be manipulated. The bandwidth of the cross polarization converter is 82% of the central frequency,covering the range from 15.7 GHz to 37.5 GHz. The conversion efficiency of the innovative new design is higher than 90%.At 14.43 GHz and 40.95 GHz, the linearly polarized incident wave is converted into a circularly polarized wave.
基金Project supported by the National Natural Science Fundation of China(Grant No.11404286)the Natural Science Fundation of Zhejiang Province,China(Grant No.LY15F050010)the Scientific Research Foundation of Zhejiang University of Technology,China(Grant No.1401109012408)
文摘Based on the designed As2Se3 and As2S3 chalcogenide glass photonic crystal fiber（PCF） and the scalar nonlinear Schrdinger equation,the effects of pump power and wavelength on modulation instability（MI） gain are comprehensively studied in the abnormal dispersion regime of chalcogenide glass PCF.Owing to high Raman effect and high nonlinearity,ultra-broadband MI gain is obtained in chalcogenide glass PCF.By choosing the appropriate pump parameter,the MI gain bandwidth reaches 2738 nm for the As2Se3 glass PCF in the abnormal-dispersion region,while it is 1961 nm for the As2S3 glass PCF.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.12174159,12274183,and 51976079)the National Key Research and Development Program of China (Grant No.2020YFC1512403)the Research Project of State Key Laboratory of Mechanical System and Vibration (Grant No.MSV202201)。
文摘The numerical simulations and experimental results of an ultra-broadband acoustic ventilation barrier composed of periodic unit cells are reported in this paper.Based on multiple mechanisms,including sound absorption by eigenmodes of the unit cell and sound reflection by a plate structure on upper surface of the unit cell,a single-layer ventilation barrier with broadband sound reduction is designed,and its working bandwidth can reach about 1560 Hz.The experimental results accord well with the simulation results.Furthermore,two types of three-layer ventilation barriers are designed and demonstrated by using the unit cells with different values of a(the length of the hollow square region)and w(the width of the channel between the adjacent cavities),and the bandwidths of both ventilation barriers can increase to 3160 Hz and 3230 Hz,respectively.The designed barrier structures have the advantages of ultra-broadband sound reduction and ventilation,which paves the way to designing high-performance ventilation barriers for the applications in environmental protection and architectural acoustics.
文摘为满足毫米波通信等应用领域对超宽带功率放大器的需求,文章采用南京电子器件研究所50 nm GaN HEMT工艺研制了一款覆盖W、F波段的超宽带功率放大器。首先,使用模型对实验数据进行拟合外推,得到宽带范围内管芯的功率阻抗;其次,采用LC结构加高低阻抗微带线方式进行宽带电路匹配,并设计了末级、级间和输入级的匹配电路拓扑结构;最后,对级间匹配电路进行综合优化调整,并采用兰格桥进行功率合成。最终,放大器在80GHz~140GHz范围内,典型线性增益达18dB,饱和输出功率达100mW,同时,在全频段范围内,芯片具有±1dB的功率平坦度和良好的回波损耗,在太赫兹领域具有广阔的应用前景。
文摘为更好地使URLLC(Ultra-Reliable and Low Latency Communications)与增强型移动宽带业务(eMBB:enhanced Mobile Broad Band)在同一载波频段有效复用,进一步提升混合业务系统性能,提出一种基于可扩展传输时间间隔(TTI:Transmission Time Interval)的动态带宽分配策略。系统根据业务类型进行带宽动态划分;时域上提升URLLC调度优先级;频域上采用不同长度的TTI进行以用户为中心的无线资源分配。动态系统级仿真表明,在不同程度的负载水平下,相比传统无线资源分配算法,该方案能在有效满足URLLC用户时延需求的前提下优化eMBB用户的吞吐量消耗,URLLC用户时延增益最高达到83.8%,提升了5G混合业务系统中不同类型业务的服务质量(QoS:Quality of Service)。
