A triple-band miniaturized end-fire antenna based on the odd modes of spoof surface plasmonic polariton(SSPP)waveguide resonator is proposed in this paper.To meet the ever increasing demand for more communication chan...A triple-band miniaturized end-fire antenna based on the odd modes of spoof surface plasmonic polariton(SSPP)waveguide resonator is proposed in this paper.To meet the ever increasing demand for more communication channels and less antenna sizes,multi-band antennas are currently under intensive investigation.By a novel feeding method,three odd modes are excited on an SSPP waveguide resonator,which performs as an end-fire antenna operating at three bands,7.15-7.26 GHz,11.6-12.2 GHz and 13.5-13.64 GHz.It exhibits reasonably high and stable maximum gains of 5.26 dBi,7.97 dBi and 10.1 dBi and maximum efficiencies of 64%,92%and 98%at the three bands,respectively.Moreover,in the second band,the main beam angle shows a frequency dependence with a total scanning angle of 19°.The miniaturized triple-band antenna has a great potential in wireless communication systems,satellite communication and radar systems.展开更多
Recent breakthroughs in the field of non-Hermitian physics present unprecedented opportunities,from fundamental theories to cutting-edge applications such as multimode lasers,unconventional wave transport,and high-per...Recent breakthroughs in the field of non-Hermitian physics present unprecedented opportunities,from fundamental theories to cutting-edge applications such as multimode lasers,unconventional wave transport,and high-performance sensors.The exceptional point,a spectral singularity widely existing in non-Hermitian systems,provides an indispensable route to enhance the sensitivity of optical detection.However,the exceptional point of the forementioned systems is set once the system is built or fabricated,and machining errors make it hard to reach such a state precisely.To this end,we develop a highly tunable and reconfigurable exceptional point system,i.e.,a single spoof plasmonic resonator suspended above a substrate and coupled with two freestanding Rayleigh scatterers.Our design offers great flexibility to control exceptional point states,enabling us to dynamically reconfigure the exceptional point formed by various multipolar modes across a broadband frequency range.Specifically,we experimentally implement five distinct exceptional points by precisely manipulating the positions of two movable Rayleigh scatterers.In addition,the enhanced perturbation strength offers remarkable sensitivity enhancement for detecting deep-subwavelength particles with the minimum dimension down to 0.001λ(withλto be the free-space wavelength).展开更多
The reflection of X-band microwaves （8-12 GHz） from a metallic aluminum （A1） surface with groove grating corrugations was investigated experimentally. It was shown that the reflection of p-polarization is much les...The reflection of X-band microwaves （8-12 GHz） from a metallic aluminum （A1） surface with groove grating corrugations was investigated experimentally. It was shown that the reflection of p-polarization is much less than the microwave reflected from the corresponding area of an unruled Al surface, with selective wavelength. The experimental results demonstrated that the anomalous microwave reflection is strongly associated with the excitation of spoof surface plasmons at the Al air interface by the surface grating coupler. This near-total absence of reflected microwaves is similar to the famous Wood＇s anomaly in the optical regime and is of fundamental importance to the applications of spoof surface plasmons in the microwave regime.展开更多
We investigate the guiding modes of spoof surface plasmon polaritons （SPPs） on a symmetric ultra-thin plasmonic structure. From the analysis, we deduce the operating frequency region of the single-mode propagation. ...We investigate the guiding modes of spoof surface plasmon polaritons （SPPs） on a symmetric ultra-thin plasmonic structure. From the analysis, we deduce the operating frequency region of the single-mode propagation. Based on this property, a spoof SPPs lowpass filter is then constituted in the microwave frequency. By introducing a transmission zero at the lower frequency band using a pair of stepped-impedance stubs, a wide passband filter is further realized. The proposed filter is fed by.a transducer composed of a microstrip line with a flaring ground. The simulated results show that the presented filter has an extremely wide upper stopband in addition to excellent passband filtering characteristics such as low loss, wide band, and high square ratio. A prototype passband filter is also fabricated to validate the predicted performances. The proposed spoof-SPPs filter is believed to be very promising for other surface waveguide components in microwave and terahertz bands.展开更多
A novel bandpass filter(BPF)based on spoof surface plasmon polaritons(SSPPs)using a compact folded slotline structure is proposed and experimentally demonstrated.The proposed novel SSPPs structure compared with a conv...A novel bandpass filter(BPF)based on spoof surface plasmon polaritons(SSPPs)using a compact folded slotline structure is proposed and experimentally demonstrated.The proposed novel SSPPs structure compared with a conventional plasmonic waveguide with slot line SSPPs unit structure at the same size,the considerable advantages in much lower asymptotic frequency with tight field confinement,which enable the proposed filter to be more miniaturization.A high-efficient mode conversion structure is designed to transition from TE-mode to SSPPs-mode by gradient slotline lengths.The low-frequency stop-band can be committed with microstrip to slotline evolution on both sides of the dielectric,while the high-frequency cutoff band is realized by the proposed SSPPs structure.The influence of dispersion relation,electric field distribution,surface current,and structural parameters on the transmission characteristics of the proposed BPF are analyzed by finite difference time domain(FDTD).To validate the design concept,the prototype of the miniaturized SSPPs BPF has been manufactured and measured.The experimental results show high performance of the fabricated sample,in which the working in a range of 0.9 GHz-5.2 GHz with the relative bandwidth is 142%,the insertion loss less than 0.5 dB,the reflection coefficient less than-10 dB,and the group delay is less than one ns.This works provides a mirror for realizing the miniaturization of waveguides,and the application and development of high-confinement SSPPs functional devices in the microwave and THz regimes.展开更多
We propose a single-beam leaky-wave antenna(LWA) with a wide-scanning angle and a high-scanning rate based on spoof surface plasmon polariton(SSPP) in this paper. The SSPP transmission line(TL) is etched with periodic...We propose a single-beam leaky-wave antenna(LWA) with a wide-scanning angle and a high-scanning rate based on spoof surface plasmon polariton(SSPP) in this paper. The SSPP transmission line(TL) is etched with periodically arranged circular patches, which converts the slow-wave mode into the fast-wave region for radiation. The proposed LWA is designed, fabricated, and tested. The simulated results imply that the proposed LWA not only achieves a high radiation efficiency of about 81.4%, and a high scanning rate of 12.12, but also has a large scanning angle of 176° over a narrow operation bandwidth of 8.3-9.6 GHz(for |S_(11)| <-10 dB). In addition, the simulated average gain of the LWA can reach as high as 10.9 d Bi. The measured scanning angle range is 175° in the operation band of 8.2-9.6 GHz, and the measured average gain is 10.6 dBi. The experimental results are consistent with the simulation, validating its performance. An antenna with high radiation efficiency, wide scanning angle range, and high scanning rate has great potential for application in radar and wireless communication systems.展开更多
A novel leaky-wave antenna(LWA)utilizing spoof surface plasmon polaritons(SSPPs)excitation is proposed with continuous scanning range from endfire to forward.The designed transmission line unit supports two SSPPS mode...A novel leaky-wave antenna(LWA)utilizing spoof surface plasmon polaritons(SSPPs)excitation is proposed with continuous scanning range from endfire to forward.The designed transmission line unit supports two SSPPS modes,of which the 2nd order mode is applied in the design.A novel strategy has been devised to excite the spatial radiation of the-1st order harmonics by arranging periodic counter changed sinusoidal structures on both sides of the SSPPs transmission line.Both full-wave simulation and measurement results show that the proposed LWA presents wide scanning angle from endfire to forward.In the frequency range from 4 GHz to 10 GHz,LWAs achieve scanning from 90°to+20°,covering the entire backward quadrant continuously.展开更多
<div style="text-align:justify;"> The optical WGM resonator plays an important role in modern physics due to its ultra-high quality factor and small volume mode. In optics, SPPs modes can effectively c...<div style="text-align:justify;"> The optical WGM resonator plays an important role in modern physics due to its ultra-high quality factor and small volume mode. In optics, SPPs modes can effectively confine electromagnetic waves at the interface between metal and dielectric, providing extremely high sensitivity. New interesting WGM phenomena will emerge when the WGM is combined with the SPPs. In this paper, a cogwheel resonator based on spoof SPPs was designed, which can generate multi-order WGM modes. The transmission coefficients, dispersion relations and resonance modes of the WGM resonator were analyzed. The proposed resonator extends the WGM mode from optical band to microwave band, providing a new perspective for the applications of WGM mode at microwave band. </div>展开更多
A polarization-insensitive unidirectional spoof surface plasmon polariton（SPP） coupler mediated by a gradient metasurface is proposed. The field distributions and average Poynting vector of the coupled spoof SPPs ar...A polarization-insensitive unidirectional spoof surface plasmon polariton（SPP） coupler mediated by a gradient metasurface is proposed. The field distributions and average Poynting vector of the coupled spoof SPPs are analyzed. The simulated and experimental results support the theoretical analysis and indicate that the designed gradient metasurface can couple both the parallel-polarized and normally-polarized incident waves to the spoof SPPs propagating in the same direction at about 5 GHz.展开更多
It has been recently demonstrated that negative-index dispersion and mode degeneracy can be achieved by manipulating a spoof-insulator-spoof（SIS） waveguide. In this paper, we propose a new SIS waveguide, which is co...It has been recently demonstrated that negative-index dispersion and mode degeneracy can be achieved by manipulating a spoof-insulator-spoof（SIS） waveguide. In this paper, we propose a new SIS waveguide, which is composed of two spoof surface plasmon polaritons（SSPPs） waveguides drilled with periodic rhomboidal grooves. Both the symmetric and asymmetric cases are investigated. Our simulation results show that the asymmetric SIS waveguides are more significant.By tailoring the tilt of the rhomboidal grooves, the negative-index dispersion can be achieved and the microwave band gap（MBG） can be effectively modulated. At a critical tilt, there appears an accidental mode degeneracy at the edge of the first Brillouin zone. The excitation and propagation of the two coupled modes sustained by the asymmetric SIS waveguides are also demonstrated.展开更多
Resonantly enhanced dielectric sensing has superior sensitivity and accuracy because the signal is measured from relative resonance shifts that are immune to signal fluctuations.For applications in the Internet of Thi...Resonantly enhanced dielectric sensing has superior sensitivity and accuracy because the signal is measured from relative resonance shifts that are immune to signal fluctuations.For applications in the Internet of Things(IoT),accurate detection of resonance frequency shifts using a compact circuit is in high demand.We proposed an ultracompact integrated sensing system that merges a spoof surface plasmon resonance sensor with signal detection,processing,and wireless communication.A softwaredefined scheme was developed to track the resonance shift,which minimized the hardware circuit and made the detection adaptive to the target resonance.A microwave spoof surface plasmon resonator was designed to enhance sensitivity and resonance intensity.The integrated sensing system was constructed on a printed circuit board with dimensions of 1.8 cm×1.2 cm and connected to a smartphone wirelessly through Bluetooth,working in both frequency scanning mode and resonance tracking mode and achieving a signal-to-noise ratio of 69 dB in acetone vapor sensing.This study provides an ultracompact,accurate,adaptive,sensitive,and wireless solution for resonant sensors in the IoT.展开更多
Circulators play a significant role in radar and microwave communication systems.This paper proposes a broadband and highly efficient plasmonic circulator,which consists of spoof surface plasmon polaritons(SSPPs)waveg...Circulators play a significant role in radar and microwave communication systems.This paper proposes a broadband and highly efficient plasmonic circulator,which consists of spoof surface plasmon polaritons(SSPPs)waveguides and ferrite disks to support non-reciprocal mode coupling.The simulated performance of symmetrically designed circulator shows that it has an insertion loss of roughly 0.5 dB while the isolation and return loss is more than 12 dB in the frequency range of 6.0 GHz–10.0 GHz(relative bandwidth of 50%).Equivalent circuit model has been proposed to explain the operating mechanism of the plasmonic circulator.The equivalent circuit model,numerical simulations,and experimental results are consistent with each other,which demonstrates the good performance of the proposed plasmonic circulator.展开更多
Bound states can be supported on the surface of a periodically corrugated perfect conductor known as spoof surface plasmon polaritons with their dispersion curves reside below the light line.Here we show that bound st...Bound states can be supported on the surface of a periodically corrugated perfect conductor known as spoof surface plasmon polaritons with their dispersion curves reside below the light line.Here we show that bound states in the continuum(BICs)can also be achieved in such systems.Two types of grating structures are proposed to suppress the radiation leakage and hence generate bound states.The first one is a simple grating with broad grooves in which multiple cavity modes are accommodated.Due to the symmetry incompatibility and the destructive interaction mainly from the TM_(0)and TM_(1)modes,BICs at theΓpoint and at off-Γpoints are both realized.The second one is a dimerized grating with two grooves in each unit cell.The destructive interaction between the modes in the two grooves can suppresses the radiation and BICs at theΓpoint are observed.The Q factors of the whole bands can be further tuned by the dimerization strength effectively.This work may offer new opportunity for the applications of metallic grating in the low frequency bands.展开更多
Although tremendous efforts have been devoted to investigating planar single-conductor circuits,it remains challenging to provide tight confinement of electromagnetic field and compatibility with active semi-conductor...Although tremendous efforts have been devoted to investigating planar single-conductor circuits,it remains challenging to provide tight confinement of electromagnetic field and compatibility with active semi-conductor components such as amplifier,harmonic generator and mixers.Single-conductor spoof surface plasmon polariton(SSPP)structure,which is one of the most promising planar single-conductor transmission media due to the outstanding field confinement,still suf-fers from the difficulty in integrating with the active semi-conductor components.In this paper,a new kind of odd-mode-metachannel(OMM)that can support odd-mode SSPPs is proposed to perform as the fundamental transmission chan-nel of the single-conductor systems.By introducing zigzag decoration,the OMM can strengthen the field confinement and broaden the bandwidth of odd-mode SSPPs simultaneously.More importantly,the active semi-conductor amplifier chip integration is achieved by utilizing the intrinsic potential difference on OMM,which breaks the major obstacle in im-plementing the single-conductor systems.As an instance,an amplifier is successfully integrated on the single-conductor OMM,which can realize both loss compensation and signal amplification.Meanwhile,the merits of OMM including crosstalk suppression,low radar cross section(RCS),and flexibility are comprehensively demonstrated.Hence,the pro-posed OMM and its capability to integrate with the active semi-conductor components may provide a new avenue to fu-ture single-conductor conformal systems and smart skins.展开更多
Smart antennas have received great attention for their potentials to enable communication and perception functions at the same time.However,realizing the function synthesis remains an open challenge,and most existing ...Smart antennas have received great attention for their potentials to enable communication and perception functions at the same time.However,realizing the function synthesis remains an open challenge,and most existing system solutions are limited to narrow operating bands and high complexity and cost.Here,we propose an externally perceivable leakywave antenna(LWA)based on spoof surface plasmon polaritons(SSPPs),which can realize adaptive real-time switching between the“radiating”and“non-radiating”states and beam tracking at different frequencies.With the assistance of computer vision,the smart SSPP-LWA is able to detect the external target user or jammer,and intelligently track the target by self-adjusting the operating frequency.The proposed scheme helps to reduce the power consumption through dynamically controlling the radiating state of the antenna,and improve spectrum utilization and avoid spectrum conflicts through intelligently deciding the radiating frequency.On the other hand,it is also helpful for the physical layer communication security through switching the antenna working state according to the presence of the target and target beam tracking in real time.In addition,the proposed smart antenna can be generalized to other metamaterial systems and could be a candidate for synaesthesia integration in future smart antenna systems.展开更多
We present a dynamically reconfigurable spoof surface plasmon polariton(SSPP)waveguide capable of bidirectional switching between perfect absorption and perfect transmission through active control.Nonlinear varactor d...We present a dynamically reconfigurable spoof surface plasmon polariton(SSPP)waveguide capable of bidirectional switching between perfect absorption and perfect transmission through active control.Nonlinear varactor diodes are integrated into the waveguide,enabling degenerate phase matching between pump and signal waves via voltage-tuned dispersion engineering.Three-wave mixing processes are established,allowing bidirectional phase-controlled transitions from destructive to constructive interference.The proposed SSPP waveguide overcomes traditional pumping constraints with its bidirectional configuration,supporting both forward-and backward-propagating pump-signal configurations and permitting signal amplitude modulations at both the transmitter and receiver ends.Experimental characterization demonstrates remarkable signal gain tunability:the forward pumping configuration achieves a dynamic range spanning from−69.50 to+1.04 dB,while the backward configuration spans from−70.49 to+1.45 dB.This work provides new design paradigms for microwave coherent systems and advances the development of reconfigurable electromagnetic devices for adaptive energy harvesting and high-speed signal processing applications.展开更多
Beam-frequency-scanning detection and point-to-point communication typically differ significantly in bandwidth and polarization characteristics,requiring two separate antennas in conventional designs.This paper propos...Beam-frequency-scanning detection and point-to-point communication typically differ significantly in bandwidth and polarization characteristics,requiring two separate antennas in conventional designs.This paper proposes a method to integrate a dual-mode radiation of narrowband circular polarization(CP)into a broadband linearly polarized(LP)beam-scanning leaky-wave antenna(LWA)using a full spoof surface plasmon polariton(SSPP)system.First,a grooved SSPP unit and its complementary structure are used with periodic mode modulation to achieve continuous vertically polarized(V-pol)dual-beam scanning from backward to forward.By periodically embedding spoof localized surface plasmon(SLSP)units,strong coupling between SLSPs and SSPPs is enabled under resonant conditions.Then,CP radiation is generated due to the rotating electric-field vectors of SLSPs.Experiment and simulation results demonstrate continuous V-pol beam scanning from−30°to 22°across 4.25–6.75 GHz,including effective broadside radiation.Notably,at 5.4 GHz,the antenna radiates right-handed circularly polarized(RHCP)and left-handed circularly polarized(LHCP)waves in opposite broadside directions.Compared with existing technologies,the insertable CP radiation allows the antenna to enable two significantly different operating modes,which can be applied in combined beam-scanning detection and narrowband satellite emergency communication,greatly improving system integration.展开更多
Controlling energy flow in waveguides has attractive potential in integrated devices from radio frequencies to optical bands.Due to the spin-orbit coupling,the mirror symmetry will be broken,and the handedness of the ...Controlling energy flow in waveguides has attractive potential in integrated devices from radio frequencies to optical bands.Due to the spin-orbit coupling,the mirror symmetry will be broken,and the handedness of the near-field source will determine the direction of energy transport.Compared with well-established theories about spin-momentum locking,experimental visualization of unidirectional coupling is usually challenging due to the lack of generic chiral sources and the strict environmental requirement.In this work,we design a broadband near-field chiral source in the microwave band and discuss experimental details to visualize spin-momentum locking in three different metamaterial waveguides,including spoof surface plasmon polaritons,line waves,and valley topological insulators.The similarity of these edge waves relies on the abrupt sign change of intrinsic characteristics of two media across the interface.In addition to the development of experimental technology,the advantages and research status of interface waveguides are summarized,and perspectives on future research are presented to explore an avenue for designing controllable spin-sorting devices in the microwave band.展开更多
Glide symmetry,which is one kind of higher symmetry,is introduced in a special type of plasmonic metamaterial,the transmission lines(TLs)of spoof surface plasmon polaritons(SSPPs),in order to control the dispersion ch...Glide symmetry,which is one kind of higher symmetry,is introduced in a special type of plasmonic metamaterial,the transmission lines(TLs)of spoof surface plasmon polaritons(SSPPs),in order to control the dispersion characteristics and modal fields of the SSPPs.We show that the glide-symmetric TL presents merged pass bands and mode degeneracy,which lead to broad working bandwidth and extremely low coupling between neighboring TLs.Dual-conductor SSPP TLs with and without glide symmetry are arranged in parallel as two channels with very deep subwavelength separation(e.g.,λ0∕100 at 5 GHz)for the application of integrated circuits and systems.Mutual coupling between the hybrid channels is analyzed using coupled mode theory and characterized in terms of scattering parameters and near-field distributions.We demonstrate theoretically and experimentally that the hybrid TL array obtains significantly more suppressed crosstalk than the uniform array of two nonglide symmetric TLs.Hence,it is concluded that the glide symmetry can be adopted to flexibly design the propagation of SSPPs and benefit the development of highly compact plasmonic circuits.展开更多
Metamaterial devices(metadevices)have been developed in progress aiming to generate extraordinary performance over traditional de-vices in the(sub-)terahertz(THz)domain,and their planar integra-tion with complementary...Metamaterial devices(metadevices)have been developed in progress aiming to generate extraordinary performance over traditional de-vices in the(sub-)terahertz(THz)domain,and their planar integra-tion with complementary-metal-oxide-semiconductor(CMOS)cir-cuits pave a new way to build miniature silicon plasmonics that over-comes existing challenges in chip-to-chip communication.In an effort towards low-power,crosstalk-tolerance,and high-speed data link for future exascale data centers,this article reviews the recent progress on two metamaterials,namely,the spoof surface plasmon polaritons(SPPs),and the split-ring resonator(SRR),as well as their imple-mentations in silicon,focusing primarily on their fundamental the-ories,design methods,and implementations for future THz commu-nications.Owing to their respective dispersion characteristic at THz,these two metadevices are highly expected to play an important role in miniature integrated circuits and systems toward compact size,dense integration,and outstanding performance.A design example of a fully integrated sub-THz CMOS silicon plasmonic system integrating these two metadevices is provided to demonstrate a dual-channel crosstalk-tolerance and energy-efficient on-off keying(OOK)communication system.Future directions and potential applications for THz metade-vices are discussed.展开更多
基金supported in part by the Natural Science Foundation of Tianjin(No.19JCYBJC16100)the Tianjin Innovation and Entrepreneurship Training Program(No.202210060027)。
文摘A triple-band miniaturized end-fire antenna based on the odd modes of spoof surface plasmonic polariton(SSPP)waveguide resonator is proposed in this paper.To meet the ever increasing demand for more communication channels and less antenna sizes,multi-band antennas are currently under intensive investigation.By a novel feeding method,three odd modes are excited on an SSPP waveguide resonator,which performs as an end-fire antenna operating at three bands,7.15-7.26 GHz,11.6-12.2 GHz and 13.5-13.64 GHz.It exhibits reasonably high and stable maximum gains of 5.26 dBi,7.97 dBi and 10.1 dBi and maximum efficiencies of 64%,92%and 98%at the three bands,respectively.Moreover,in the second band,the main beam angle shows a frequency dependence with a total scanning angle of 19°.The miniaturized triple-band antenna has a great potential in wireless communication systems,satellite communication and radar systems.
基金supported by the National Natural Science Foundation of China(Grant Nos.61871215,61771238,and 61701246)the National Key Research and Development Program of China(Grant No.2022YFA1404903)+9 种基金the Fund of Qing Lan Project of Jiangsu Province(Grant No.1004-YQR22031)the Six Talent Peaks Project in Jiangsu Province(Grant No.2018-GDZB-009)the Fund of Prospective Layout of Scientific Research for NUAA(Nanjing University of Aeronautics and Astronautics)(Grant Nos.1004-ILA22002 and 1004-ILA22068)the Research and Practice Innovation Program of Nanjing University of Aeronautics and Astronautics(Grant No.xcxjh20210408)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX22_0364)the Fundamental Research Funds for the Central Universities,NUAA(Grant No.NS2023022)the Nanjing University of Aeronautics and Astronautics Startup Grant(Grant No.1004-YQR23031)the Distinguished Professor Fund of Jiangsu Province(Grant No.1004-YQR24010)Fundamental Research Funds for the Central Universities,NUAA(No.NE2024007)the Singapore National Research Foundation Competitive Research Program(NRF-CRP22-2019-0006).
文摘Recent breakthroughs in the field of non-Hermitian physics present unprecedented opportunities,from fundamental theories to cutting-edge applications such as multimode lasers,unconventional wave transport,and high-performance sensors.The exceptional point,a spectral singularity widely existing in non-Hermitian systems,provides an indispensable route to enhance the sensitivity of optical detection.However,the exceptional point of the forementioned systems is set once the system is built or fabricated,and machining errors make it hard to reach such a state precisely.To this end,we develop a highly tunable and reconfigurable exceptional point system,i.e.,a single spoof plasmonic resonator suspended above a substrate and coupled with two freestanding Rayleigh scatterers.Our design offers great flexibility to control exceptional point states,enabling us to dynamically reconfigure the exceptional point formed by various multipolar modes across a broadband frequency range.Specifically,we experimentally implement five distinct exceptional points by precisely manipulating the positions of two movable Rayleigh scatterers.In addition,the enhanced perturbation strength offers remarkable sensitivity enhancement for detecting deep-subwavelength particles with the minimum dimension down to 0.001λ(withλto be the free-space wavelength).
基金Project supported by the National Basic Research Program of China(Grant No.2008CB717800)the Doctoral Program o fMinistry of Education of China(Grant No.20093402110027)
文摘The reflection of X-band microwaves （8-12 GHz） from a metallic aluminum （A1） surface with groove grating corrugations was investigated experimentally. It was shown that the reflection of p-polarization is much less than the microwave reflected from the corresponding area of an unruled Al surface, with selective wavelength. The experimental results demonstrated that the anomalous microwave reflection is strongly associated with the excitation of spoof surface plasmons at the Al air interface by the surface grating coupler. This near-total absence of reflected microwaves is similar to the famous Wood＇s anomaly in the optical regime and is of fundamental importance to the applications of spoof surface plasmons in the microwave regime.
基金Project supported by the Key Grant Project of Ministry of Education of China(Grant No.313029)the FDCT Research Grant from Macao Science and Technology Development Fund,China(Grant No.051/2014/A1)the Multi-Year Research Grant from University of Macao,Macao SAR,China(Grant No.MYRG2014-00079-FST)
文摘We investigate the guiding modes of spoof surface plasmon polaritons （SPPs） on a symmetric ultra-thin plasmonic structure. From the analysis, we deduce the operating frequency region of the single-mode propagation. Based on this property, a spoof SPPs lowpass filter is then constituted in the microwave frequency. By introducing a transmission zero at the lower frequency band using a pair of stepped-impedance stubs, a wide passband filter is further realized. The proposed filter is fed by.a transducer composed of a microstrip line with a flaring ground. The simulated results show that the presented filter has an extremely wide upper stopband in addition to excellent passband filtering characteristics such as low loss, wide band, and high square ratio. A prototype passband filter is also fabricated to validate the predicted performances. The proposed spoof-SPPs filter is believed to be very promising for other surface waveguide components in microwave and terahertz bands.
基金the National Natural Science Foundation of China(Grant Nos.62071221 and 62071442)the Equipment Advance Research Foundation of China(Grant No.80909010302)the Key Laboratory of Radar Imaging and Microwave Photonics(Nanjing University of Aeronautics and Astronautics),Ministry of Education of China(Grant No.NJ20210006).
文摘A novel bandpass filter(BPF)based on spoof surface plasmon polaritons(SSPPs)using a compact folded slotline structure is proposed and experimentally demonstrated.The proposed novel SSPPs structure compared with a conventional plasmonic waveguide with slot line SSPPs unit structure at the same size,the considerable advantages in much lower asymptotic frequency with tight field confinement,which enable the proposed filter to be more miniaturization.A high-efficient mode conversion structure is designed to transition from TE-mode to SSPPs-mode by gradient slotline lengths.The low-frequency stop-band can be committed with microstrip to slotline evolution on both sides of the dielectric,while the high-frequency cutoff band is realized by the proposed SSPPs structure.The influence of dispersion relation,electric field distribution,surface current,and structural parameters on the transmission characteristics of the proposed BPF are analyzed by finite difference time domain(FDTD).To validate the design concept,the prototype of the miniaturized SSPPs BPF has been manufactured and measured.The experimental results show high performance of the fabricated sample,in which the working in a range of 0.9 GHz-5.2 GHz with the relative bandwidth is 142%,the insertion loss less than 0.5 dB,the reflection coefficient less than-10 dB,and the group delay is less than one ns.This works provides a mirror for realizing the miniaturization of waveguides,and the application and development of high-confinement SSPPs functional devices in the microwave and THz regimes.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 62171460 and 61801508)the Natural Science Basic Research Program of Shaanxi Province, China (Grant Nos. 2020JM-350, 20200108, 20210110, and 2020022)the Postdoctoral Innovative Talents Support Program of China (Grant Nos. BX20180375, 2019M653960, and 2021T140111)。
文摘We propose a single-beam leaky-wave antenna(LWA) with a wide-scanning angle and a high-scanning rate based on spoof surface plasmon polariton(SSPP) in this paper. The SSPP transmission line(TL) is etched with periodically arranged circular patches, which converts the slow-wave mode into the fast-wave region for radiation. The proposed LWA is designed, fabricated, and tested. The simulated results imply that the proposed LWA not only achieves a high radiation efficiency of about 81.4%, and a high scanning rate of 12.12, but also has a large scanning angle of 176° over a narrow operation bandwidth of 8.3-9.6 GHz(for |S_(11)| <-10 dB). In addition, the simulated average gain of the LWA can reach as high as 10.9 d Bi. The measured scanning angle range is 175° in the operation band of 8.2-9.6 GHz, and the measured average gain is 10.6 dBi. The experimental results are consistent with the simulation, validating its performance. An antenna with high radiation efficiency, wide scanning angle range, and high scanning rate has great potential for application in radar and wireless communication systems.
文摘A novel leaky-wave antenna(LWA)utilizing spoof surface plasmon polaritons(SSPPs)excitation is proposed with continuous scanning range from endfire to forward.The designed transmission line unit supports two SSPPS modes,of which the 2nd order mode is applied in the design.A novel strategy has been devised to excite the spatial radiation of the-1st order harmonics by arranging periodic counter changed sinusoidal structures on both sides of the SSPPs transmission line.Both full-wave simulation and measurement results show that the proposed LWA presents wide scanning angle from endfire to forward.In the frequency range from 4 GHz to 10 GHz,LWAs achieve scanning from 90°to+20°,covering the entire backward quadrant continuously.
文摘<div style="text-align:justify;"> The optical WGM resonator plays an important role in modern physics due to its ultra-high quality factor and small volume mode. In optics, SPPs modes can effectively confine electromagnetic waves at the interface between metal and dielectric, providing extremely high sensitivity. New interesting WGM phenomena will emerge when the WGM is combined with the SPPs. In this paper, a cogwheel resonator based on spoof SPPs was designed, which can generate multi-order WGM modes. The transmission coefficients, dispersion relations and resonance modes of the WGM resonator were analyzed. The proposed resonator extends the WGM mode from optical band to microwave band, providing a new perspective for the applications of WGM mode at microwave band. </div>
基金Project supported by the China Postdoctoral Science Foundation(Grant No.2015M580849)the National Natural Science Foundation of China(Grant Nos.61471292,61501365,61471388,6133100541404095,and 41390454)
文摘A polarization-insensitive unidirectional spoof surface plasmon polariton（SPP） coupler mediated by a gradient metasurface is proposed. The field distributions and average Poynting vector of the coupled spoof SPPs are analyzed. The simulated and experimental results support the theoretical analysis and indicate that the designed gradient metasurface can couple both the parallel-polarized and normally-polarized incident waves to the spoof SPPs propagating in the same direction at about 5 GHz.
基金Project supported by the National Basic Research Program of China(Grant No.2013CBA01702)the National Natural Science Foundation of China(Grant Nos.61377016,61575055,10974039,61307072,61308017,and 61405056)
文摘It has been recently demonstrated that negative-index dispersion and mode degeneracy can be achieved by manipulating a spoof-insulator-spoof（SIS） waveguide. In this paper, we propose a new SIS waveguide, which is composed of two spoof surface plasmon polaritons（SSPPs） waveguides drilled with periodic rhomboidal grooves. Both the symmetric and asymmetric cases are investigated. Our simulation results show that the asymmetric SIS waveguides are more significant.By tailoring the tilt of the rhomboidal grooves, the negative-index dispersion can be achieved and the microwave band gap（MBG） can be effectively modulated. At a critical tilt, there appears an accidental mode degeneracy at the edge of the first Brillouin zone. The excitation and propagation of the two coupled modes sustained by the asymmetric SIS waveguides are also demonstrated.
基金supported by the National Natural Science Foundation of China(62288101,61701108,and 61631007)the National Key Research and Development Program of China(2017YFA0700201,2017YFA0700202,and 2017YFA0700203)+1 种基金the Major Project of Natural Science Foundation of Jiangsu Province(BK20212002)the 111 Project(111-2-05).
文摘Resonantly enhanced dielectric sensing has superior sensitivity and accuracy because the signal is measured from relative resonance shifts that are immune to signal fluctuations.For applications in the Internet of Things(IoT),accurate detection of resonance frequency shifts using a compact circuit is in high demand.We proposed an ultracompact integrated sensing system that merges a spoof surface plasmon resonance sensor with signal detection,processing,and wireless communication.A softwaredefined scheme was developed to track the resonance shift,which minimized the hardware circuit and made the detection adaptive to the target resonance.A microwave spoof surface plasmon resonator was designed to enhance sensitivity and resonance intensity.The integrated sensing system was constructed on a printed circuit board with dimensions of 1.8 cm×1.2 cm and connected to a smartphone wirelessly through Bluetooth,working in both frequency scanning mode and resonance tracking mode and achieving a signal-to-noise ratio of 69 dB in acetone vapor sensing.This study provides an ultracompact,accurate,adaptive,sensitive,and wireless solution for resonant sensors in the IoT.
基金Project supported by the Six-Talent-Peaks Project in Jiangsu Province of China(Grant No.XYDXX-072)the National Natural Science Foundation of China(Grant No.61372048).
文摘Circulators play a significant role in radar and microwave communication systems.This paper proposes a broadband and highly efficient plasmonic circulator,which consists of spoof surface plasmon polaritons(SSPPs)waveguides and ferrite disks to support non-reciprocal mode coupling.The simulated performance of symmetrically designed circulator shows that it has an insertion loss of roughly 0.5 dB while the isolation and return loss is more than 12 dB in the frequency range of 6.0 GHz–10.0 GHz(relative bandwidth of 50%).Equivalent circuit model has been proposed to explain the operating mechanism of the plasmonic circulator.The equivalent circuit model,numerical simulations,and experimental results are consistent with each other,which demonstrates the good performance of the proposed plasmonic circulator.
基金Project supported by the National Natural Science Foundation of China(Grant No.12074049)the Fundamental Research Funds for the Central Universities,China(Grant Nos.2020CDJQY-Z006 and 2019CDXZWL002).
文摘Bound states can be supported on the surface of a periodically corrugated perfect conductor known as spoof surface plasmon polaritons with their dispersion curves reside below the light line.Here we show that bound states in the continuum(BICs)can also be achieved in such systems.Two types of grating structures are proposed to suppress the radiation leakage and hence generate bound states.The first one is a simple grating with broad grooves in which multiple cavity modes are accommodated.Due to the symmetry incompatibility and the destructive interaction mainly from the TM_(0)and TM_(1)modes,BICs at theΓpoint and at off-Γpoints are both realized.The second one is a dimerized grating with two grooves in each unit cell.The destructive interaction between the modes in the two grooves can suppresses the radiation and BICs at theΓpoint are observed.The Q factors of the whole bands can be further tuned by the dimerization strength effectively.This work may offer new opportunity for the applications of metallic grating in the low frequency bands.
基金financial supports from the National Natural Science Foundation of China under Grant Nos.62101122,61871127,61701108 and 61631007Natural Science Foundation of Jiangsu Province under Grant BK20210212the 111 Project under Grant No.111-2-05.
文摘Although tremendous efforts have been devoted to investigating planar single-conductor circuits,it remains challenging to provide tight confinement of electromagnetic field and compatibility with active semi-conductor components such as amplifier,harmonic generator and mixers.Single-conductor spoof surface plasmon polariton(SSPP)structure,which is one of the most promising planar single-conductor transmission media due to the outstanding field confinement,still suf-fers from the difficulty in integrating with the active semi-conductor components.In this paper,a new kind of odd-mode-metachannel(OMM)that can support odd-mode SSPPs is proposed to perform as the fundamental transmission chan-nel of the single-conductor systems.By introducing zigzag decoration,the OMM can strengthen the field confinement and broaden the bandwidth of odd-mode SSPPs simultaneously.More importantly,the active semi-conductor amplifier chip integration is achieved by utilizing the intrinsic potential difference on OMM,which breaks the major obstacle in im-plementing the single-conductor systems.As an instance,an amplifier is successfully integrated on the single-conductor OMM,which can realize both loss compensation and signal amplification.Meanwhile,the merits of OMM including crosstalk suppression,low radar cross section(RCS),and flexibility are comprehensively demonstrated.Hence,the pro-posed OMM and its capability to integrate with the active semi-conductor components may provide a new avenue to fu-ture single-conductor conformal systems and smart skins.
基金supports from the National Natural Science Foundation of China(Grant Nos.62288101,and 61971134)National Key Research and Development Program of China(Grant Nos.2021YFB3200502,and 2017YFA0700200)+2 种基金the Major Project of the Natural Science Foundation of Jiangsu Province(Grant No.BK20212002)the Fundamental Research Funds for Central Universities(Grant No.2242021R41078)the 111 Project(Grant No.111-2-05).
文摘Smart antennas have received great attention for their potentials to enable communication and perception functions at the same time.However,realizing the function synthesis remains an open challenge,and most existing system solutions are limited to narrow operating bands and high complexity and cost.Here,we propose an externally perceivable leakywave antenna(LWA)based on spoof surface plasmon polaritons(SSPPs),which can realize adaptive real-time switching between the“radiating”and“non-radiating”states and beam tracking at different frequencies.With the assistance of computer vision,the smart SSPP-LWA is able to detect the external target user or jammer,and intelligently track the target by self-adjusting the operating frequency.The proposed scheme helps to reduce the power consumption through dynamically controlling the radiating state of the antenna,and improve spectrum utilization and avoid spectrum conflicts through intelligently deciding the radiating frequency.On the other hand,it is also helpful for the physical layer communication security through switching the antenna working state according to the presence of the target and target beam tracking in real time.In addition,the proposed smart antenna can be generalized to other metamaterial systems and could be a candidate for synaesthesia integration in future smart antenna systems.
基金Project supported by the National Natural Science Foundation of China(Nos.62271139 and U21A20459)the National Key Research and Development Program of China(No.2022YFA1404903)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.3304002304D)。
文摘We present a dynamically reconfigurable spoof surface plasmon polariton(SSPP)waveguide capable of bidirectional switching between perfect absorption and perfect transmission through active control.Nonlinear varactor diodes are integrated into the waveguide,enabling degenerate phase matching between pump and signal waves via voltage-tuned dispersion engineering.Three-wave mixing processes are established,allowing bidirectional phase-controlled transitions from destructive to constructive interference.The proposed SSPP waveguide overcomes traditional pumping constraints with its bidirectional configuration,supporting both forward-and backward-propagating pump-signal configurations and permitting signal amplitude modulations at both the transmitter and receiver ends.Experimental characterization demonstrates remarkable signal gain tunability:the forward pumping configuration achieves a dynamic range spanning from−69.50 to+1.04 dB,while the backward configuration spans from−70.49 to+1.45 dB.This work provides new design paradigms for microwave coherent systems and advances the development of reconfigurable electromagnetic devices for adaptive energy harvesting and high-speed signal processing applications.
基金National Natural Science Foundation of China(62401133,62071117,62288101)111 Project(111-2-05)+3 种基金Natural Science Foundation of Jiangsu Province(BK20230192)Science and Technology Research Funds of Wuxi TaihuLight Program(K20231007)Sichuan Province Engineering Research Center for Broadband Microwave Circuit High Density IntegrationYoung Elite Scientists Sponsorship Program by Jiangsu Association for Science and Technology.
文摘Beam-frequency-scanning detection and point-to-point communication typically differ significantly in bandwidth and polarization characteristics,requiring two separate antennas in conventional designs.This paper proposes a method to integrate a dual-mode radiation of narrowband circular polarization(CP)into a broadband linearly polarized(LP)beam-scanning leaky-wave antenna(LWA)using a full spoof surface plasmon polariton(SSPP)system.First,a grooved SSPP unit and its complementary structure are used with periodic mode modulation to achieve continuous vertically polarized(V-pol)dual-beam scanning from backward to forward.By periodically embedding spoof localized surface plasmon(SLSP)units,strong coupling between SLSPs and SSPPs is enabled under resonant conditions.Then,CP radiation is generated due to the rotating electric-field vectors of SLSPs.Experiment and simulation results demonstrate continuous V-pol beam scanning from−30°to 22°across 4.25–6.75 GHz,including effective broadside radiation.Notably,at 5.4 GHz,the antenna radiates right-handed circularly polarized(RHCP)and left-handed circularly polarized(LHCP)waves in opposite broadside directions.Compared with existing technologies,the insertable CP radiation allows the antenna to enable two significantly different operating modes,which can be applied in combined beam-scanning detection and narrowband satellite emergency communication,greatly improving system integration.
基金supported by the State Key Laboratory of Millimeter Waves(Grant No.K202202)support of the National Key Research and Development Program of China(Grant Nos.2017YFA0700201,2017YFA0700202,and2017YFA0700203)。
文摘Controlling energy flow in waveguides has attractive potential in integrated devices from radio frequencies to optical bands.Due to the spin-orbit coupling,the mirror symmetry will be broken,and the handedness of the near-field source will determine the direction of energy transport.Compared with well-established theories about spin-momentum locking,experimental visualization of unidirectional coupling is usually challenging due to the lack of generic chiral sources and the strict environmental requirement.In this work,we design a broadband near-field chiral source in the microwave band and discuss experimental details to visualize spin-momentum locking in three different metamaterial waveguides,including spoof surface plasmon polaritons,line waves,and valley topological insulators.The similarity of these edge waves relies on the abrupt sign change of intrinsic characteristics of two media across the interface.In addition to the development of experimental technology,the advantages and research status of interface waveguides are summarized,and perspectives on future research are presented to explore an avenue for designing controllable spin-sorting devices in the microwave band.
基金This work was supported in part from the National Natural Science Foundation of China under Grant Nos.61631007 and 61971134,in part from the 111 Project under Grant No.111-2-05in part from the Fundamental Research Funds for the Central Universities under Grant No.2242020R40079.Xiao Tian Yan and Wenxuan Tang contributed equally to this work.
文摘Glide symmetry,which is one kind of higher symmetry,is introduced in a special type of plasmonic metamaterial,the transmission lines(TLs)of spoof surface plasmon polaritons(SSPPs),in order to control the dispersion characteristics and modal fields of the SSPPs.We show that the glide-symmetric TL presents merged pass bands and mode degeneracy,which lead to broad working bandwidth and extremely low coupling between neighboring TLs.Dual-conductor SSPP TLs with and without glide symmetry are arranged in parallel as two channels with very deep subwavelength separation(e.g.,λ0∕100 at 5 GHz)for the application of integrated circuits and systems.Mutual coupling between the hybrid channels is analyzed using coupled mode theory and characterized in terms of scattering parameters and near-field distributions.We demonstrate theoretically and experimentally that the hybrid TL array obtains significantly more suppressed crosstalk than the uniform array of two nonglide symmetric TLs.Hence,it is concluded that the glide symmetry can be adopted to flexibly design the propagation of SSPPs and benefit the development of highly compact plasmonic circuits.
基金supported by National Natural Science Founda-tion of China(NSFC)(Key Program Grant No.62034007)the Key-Area Research and Development Program of Guangdong Province(Grant No.2019B010116002)+3 种基金Guangdong Basic and Applied Basic Research Founda-tion(Grant 2019B1515120024)Shenzhen Science and Technology Program(Grant No.KQTD20200820113051096)supported by Na-tional Natural Science Foundation of China under Grant 62101122Natural Science Foundation of Jiangsu Province under Grant BK20210212.
文摘Metamaterial devices(metadevices)have been developed in progress aiming to generate extraordinary performance over traditional de-vices in the(sub-)terahertz(THz)domain,and their planar integra-tion with complementary-metal-oxide-semiconductor(CMOS)cir-cuits pave a new way to build miniature silicon plasmonics that over-comes existing challenges in chip-to-chip communication.In an effort towards low-power,crosstalk-tolerance,and high-speed data link for future exascale data centers,this article reviews the recent progress on two metamaterials,namely,the spoof surface plasmon polaritons(SPPs),and the split-ring resonator(SRR),as well as their imple-mentations in silicon,focusing primarily on their fundamental the-ories,design methods,and implementations for future THz commu-nications.Owing to their respective dispersion characteristic at THz,these two metadevices are highly expected to play an important role in miniature integrated circuits and systems toward compact size,dense integration,and outstanding performance.A design example of a fully integrated sub-THz CMOS silicon plasmonic system integrating these two metadevices is provided to demonstrate a dual-channel crosstalk-tolerance and energy-efficient on-off keying(OOK)communication system.Future directions and potential applications for THz metade-vices are discussed.
