- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2018 IEEE International Conference on RFID Technology & Application (RFID-TA) - Macau, Macao (2018.9.26-2018.9.28)] 2018 IEEE International Conference on RFID Technology & Application (RFID-TA) - A Wideband Circularly Polarized Patch Antenna Using λ/4 and λ/2 Resonators
摘要： A wideband circularly polarized (CP) patch antenna with enhanced axial ratio (AR) bandwidth via co-design of feeding network is proposed in this paper. One λ/4 resonator and one λ/2 resonator are introduced and coupled in proximity to two orthogonal points of a square patch radiator to excite two orthogonal modes. These two resonators not only function as impedance matching elements to achieve equal magnitude of two orthogonal modes in a wide frequency band, but also provide the required 90° phase difference. In this way, two minima in the AR response appear, resulting in extended AR bandwidth. Simulated results demonstrate that 2% 3-dB AR bandwidth is achieved on a low profile of 0.014 λ0.
关键词： wideband,circularly polarized,λ/4 and λ/2 resonators
更新于2025-09-23 15:22:29
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High-Performance Tunable Narrowband SIW Cavity-Based Quadrature Hybrid Coupler
摘要： This letter presents, for the first time, a tunable narrowband substrate integrated waveguide (SIW) cavity-based quadrature hybrid coupler. Four high-quality factor (Q) SIW evanescent-mode cavity resonators are employed in the design and tuned using piezoelectric actuators. This allows the proposed coupler to have wide spurious-free range (SFR), low-power consumption, and high-power handling capability compared to other tunable planar couplers. The coupler can be tuned starting from 1.32 to 2.22 GHz with a measured insertion loss range from 1.29 to 0.7 dB. Over the full range, the measured 3-dB fractional bandwidth ranges from 5% to 18% while the phase error (∠S21 ? ∠S31) absolute bandwidth measured ±5° ranges from 40 to 82 MHz with an amplitude imbalance range between 1 and 0.3 dB. The measured reflection and isolation are better than 12 and 17 dB, respectively. Moreover, the coupler has a measured SFR of 5.1–3 fo (lowest–highest frequency).
关键词： tunable quadrature hybrid coupler,Evanescent-mode (EVA) cavity,tunable resonators
更新于2025-09-23 15:22:29
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Analytical model of the fundamental mode of 3D square split ring resonators
摘要： An analytical model is developed for the charge and potential distributions of the fundamental mode of three-dimensional (3D) singly split ring resonators (SRRs) with square cross section, which nowadays can be conveniently fabricated by additive manufacturing techniques. This model allows the derivation of approximate formulas for the equivalent capacitance and the analysis of the resonant properties of this type of SRRs at any frequency. The total capacitance is expressed as the sum of the usual gap capacitance and a surface capacitance associated with the charges on the SRR walls, which are determined from the solution for the irrotational part of the electric field of a square split cylinder obtained by conformal mapping. The applicability of the proposed model for a broad range of SRR parameters is demonstrated by comparing the resonance frequency of sample SRR configurations found theoretically with the corresponding values obtained by numerical simulations and experiments. Furthermore, the functions describing the charge and current mode profiles provided in this work can be instrumental in estimating the near-field interaction and the coupling constants of an ensemble of resonant 3D square split rings and thus for tailoring the response of metamaterials and other devices formed by these elements.
关键词： capacitance,resonance frequency,analytical model,split ring resonators,metamaterials
更新于2025-09-23 15:22:29
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Flexible Filtering Element on SOI with Wide Bandwidth tunability and Full FSR tuning
摘要： We demonstrate a Silicon-on-Insulator flexible filtering element, relying on two serially coupled micro ring resonators equipped with three thermo-optically tuned Mach-Zehnder interferometers, acting as variable optical couplers. A single electrode configuration is adopted, enabling the low-complexity thermo-optical control of the filtering element for bandwidth and wavelength tuneability. The module's performance has been studied in detail via simulation analysis and the obtained results were verified through experimental evaluation. Wide bandwidth tunability from 9 GHz to 103 GHz is achieved with a power efficiency of 0.284 mW/GHz, while full Free Spectral Range wavelength tuning is achieved with an efficiency of 0.297 mW/GHz. Module's insertion loss lays below 3 dB.
关键词： Silicon photonics,Optical switches,Microring resonators,Bandwidth flexibility,Thermo-optic control,Wavelength division multiplexing,Optical filters
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE International Ultrasonics Symposium (IUS) - Kobe, Japan (2018.10.22-2018.10.25)] 2018 IEEE International Ultrasonics Symposium (IUS) - Low-Loss, High-Frequency and Large-Coupling SH SAW Resonators Based on SiN/LiNbO<inf>3</inf>/Si
摘要： Low-loss, high-frequency and large-coupling-coefficient SAW resonators based on SiN/LN/Si are demonstrated in this study. By bonding the high-velocity Si substrate to the sub-wavelength-thick LN layer, the shear-horizontal mode SAW resonator no longer couples with the bulk modes in substrate and the leaky component is effectively eliminated. As the propagation loss is no longer the main concern for the cut angle selection, the ultra-large cut angle can be used to achieve high coupling coefficient (κ2). By carefully designing the SiN/LN/Si structure, the high-frequency and large-κ2 SAW resonators with low loss are achieved. The fabricated SAW resonators show great potential for current and next generation front ends.
关键词： SiN/LN/Si,large coupling coefficient,high frequency,low loss,SAW resonators
更新于2025-09-23 15:22:29
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Magnetic and Electric Solid-State Plasmon Spherical Resonators
摘要： Electrodynamic study of solid-state plasmon spherical resonators applicable in the range from microwave to optical frequencies is undertaken. Influence of dimensions and electromagnetic properties of media on the resonance frequency and Q-factor of these resonators is analyzed. It is shown that transcendental equations resulting from electrodynamic analysis of plasmon resonators can be also applied to the analysis of whispering gallery resonators if the resonator’s medium is isotropic, although this is a completely different kind of a resonator. Special attention is focused on the Q-factor analysis and theoretical and practical Q-factor limits for the magnetic plasmon and the electric plasmon resonators. In the addition, the impact of the finite size of a resonator on the resonance frequency and Q-factor is considered. Computations of the resonance frequency and Q-factor of magnetic plasmon resonators are supported by experiments performed at microwave frequencies.
关键词： Plasmon,Spherical resonators,Transcendental equations
更新于2025-09-23 15:21:21
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A monolithic on-chip magneto-optical isolator with 3 dB insertion loss and 40 dB isolation ratio
摘要： On-chip optical isolators constitute an essential building block for photonic integrated circuits (PICs). Here we experimentally demonstrated a magneto-optical isolator monolithically integrated on silicon featuring 3 dB insertion loss and 40 dB isolation ratio, both of which represent significant improvements over state-of-the-art. The isolator is also fully passive and operates under a simple unidirectional magnetization scheme. Such superior performance is enabled through a three-way combination of a strip-loaded waveguide design, a compositionally optimized chalcogenide glass as the light guiding medium, and low-loss taper structures created via gray-scale lithographic processing. The device represents an important step towards a practical solution for on-chip isolation in PICs.
关键词： Integrated optics devices,Magneto-optical materials,Chalcogenide glass,Resonators,Grayscale-lithography,Isolators
更新于2025-09-23 15:21:21
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Highly tunable multiple narrow emissions of dyed dielectric-metal core-shell resonators: towards efficient fluorescent labels
摘要： We report a potential efficient fluorescent label based on the dyed dielectric-metal core-shell resonators. By utilizing the near-field coupling between the dyes and the multipolar sharp cavity plasmon resonances, the dyed dielectric-metal core-shell resonators with diameter of 1.02 μm are demonstrated to be capable of supporting multiple spontaneous emission peaks with the linewidths as narrow as ~ 10 nm in visible range, and these reshaped fluorescent emissions are insensitive to the surrounding dielectric environment. Furthermore, these multiple narrow emission peaks show a precise tunability on the spectrum by simply separating a nanometric dielectric layer between the dielectric core and the metallic shell, which may provide an attractive spectral multiplexing strategy in the fields of cell biology and medical sciences.
关键词： spectral multiplexing,cavity plasmons,fluorescent label,dyed dielectric-metal core-shell resonators,quality factor
更新于2025-09-23 15:21:21
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[IEEE 2018 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization (NEMO) - Reykjavik, Iceland (2018.8.8-2018.8.10)] 2018 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization (NEMO) - Design of Frequency Tunable LTCC Coaxial SIW Filters with Constant Passband Shape
摘要： This paper deals with the design of substrate integrated coaxial ?lters in multi-layer low temperature co-?red ceramic (LTCC) technology with centre frequency tunability, while keeping constant passband characteristics along the whole tuning range. A structure consisting on switchable embedded capacitances is employed. Moreover, inner and outer layers are used for implementing frequency-dependent coupling structures, enabling to match the required input/output and inter-resonator coupling levels at the different ?lter states. Thus, a tunable ?lter with four equidistant centre frequencies in the C-band is designed with nearly constant bandwidth (BW) at the different states. Experimental results show the validity of the proposed approach for implementing frequency tunable coaxial substrate integrated waveguide (SIW) ?lters with low losses, high selectivity and compact size.
关键词： LTCC,constant passband,coaxial resonators,tunable filters,SIW
更新于2025-09-23 15:21:21
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Complete trapping of light with asymmetric plasmonic resonator arrays
摘要： Trapping/absorption of light in metallic micro/nano-structures on a dielectric-interspaced metal layer were widely studied, but discrepancies in results suggests uncertainty in its perfectness. Here we propose a modified structure with asymmetric resonance elements in each unit cell for complete trapping/absorption of light. In principle, the coupled asymmetric resonators oscillate anti-symmetrically under a critical matching condition, such that leaky radiations from the resonance elements are fully canceled in the far field, which results in guaranteed complete trapping/absorption of light in the near field. The structure may be applied in optoelectronic and bio-chemical sensing devices for strong light–matter interactions.
关键词： plasmonic resonator arrays,light trapping,optoelectronic devices,bio-chemical sensing,asymmetric resonators
更新于2025-09-23 15:21:01