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oe1(光电查) - 科学论文

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出版时间
  • 2018
研究主题
  • filtering balun
  • dual-band
  • dual-mode dielectric resonator (DR)
应用领域
  • Electronic Science and Technology
机构单位
  • Nantong University
297 条数据
?? 中文(中国)
  • Fiber-Optic Magnetic Field Sensing Based on Microfiber Knot Resonator with Magnetic Fluid Cladding

    摘要: A kind of all-fiber magnetic field sensing structure is proposed and demonstrated here. The sensing element includes a microfiber knot resonator (MKR) cladded with magnetic fluid (MF). The low-index MgF2 slab is adopted as the substrate. The sensitivity increases with the decrease of the MKR ring diameter. The achieved maximum magnetic field sensitivity is 277 pm/mT. The results of this work have the potential to promote the development of magnetically controllable optical devices and the design of ultra-compact cost-effective magnetic field sensors.

    关键词: quality factor,finesse,magnetic fluid,microfiber knot resonator

    更新于2025-11-28 14:24:03

  • Resonant electro-optic frequency comb

    摘要: High-speed optical telecommunication is enabled by wavelength-division multiplexing, whereby hundreds of individually stabilized lasers encode information within a single-mode optical fibre. Higher bandwidths require higher total optical power, but the power sent into the fibre is limited by optical nonlinearities within the fibre, and energy consumption by the light sources starts to become a substantial cost factor. Optical frequency combs have been suggested to remedy this problem by generating numerous discrete, equidistant laser lines within a monolithic device; however, at present their stability and coherence allow them to operate only within small parameter ranges. Here we show that a broadband frequency comb realized through the electro-optic effect within a high-quality whispering-gallery-mode resonator can operate at low microwave and optical powers. Unlike the usual third-order Kerr nonlinear optical frequency combs, our combs rely on the second-order nonlinear effect, which is much more efficient. Our result uses a fixed microwave signal that is mixed with an optical-pump signal to generate a coherent frequency comb with a precisely determined carrier separation. The resonant enhancement enables us to work with microwave powers that are three orders of magnitude lower than those in commercially available devices. We emphasize the practical relevance of our results to high rates of data communication. To circumvent the limitations imposed by nonlinear effects in optical communication fibres, one has to solve two problems: to provide a compact and fully integrated, yet high-quality and coherent, frequency comb generator; and to calculate nonlinear signal propagation in real time. We report a solution to the first problem.

    关键词: optical telecommunication,electro-optic effect,optical frequency combs,wavelength-division multiplexing,whispering-gallery-mode resonator

    更新于2025-11-28 14:23:57

  • Opto-thermally Excited Fabry-Perot Resonance Frequency Behaviors of Clamped Circular Graphene Membrane

    摘要: An opto-thermally excited optical fiber Fabry-Perot (F-P) resonant probe with suspended clamped circular graphene diaphragm is presented in this paper. Then, the dependence of resonance frequency behaviors of graphene diaphragm upon opto-mechanical factors including membrane properties, laser excitation parameters and film boundary conditions are investigated via COMSOL Multiphysics simulation. The results show that the radius and thickness of membrane will linearly affect the optical fiber light-induced temperature distribution, thus resulting in rapidly decreasing resonance frequency changes with the radius-to-thickness ratio. Moreover, the prestress can be regulated in the range of 108 Pa to 109 Pa by altering the environmental temperature with a scale factor of 14.2 MPa/K. It is important to note that the availability of F-P resonant probe with a defective clamped circular graphene membrane can be improved notably by fabricating the defected circular membrane to a double-end clamped beam, which gives a broader perspective to characterize the resonance performance of opto-thermally excited F-P resonators.

    关键词: opto-thermal actuation,graphene membrane,Fabry-Perot resonator,resonance frequency simulation

    更新于2025-11-28 14:23:57

  • A thin-layer dielectric and metamaterial unit-cell stack loaded miniaturized SRR-based antenna for triple narrow band 4G-LTE applications

    摘要: This article presents the design of a miniaturized dual-band antenna for long-term evolution (LTE) application is presented. In the basic antenna design, split ring resonator was loaded in the radiating plane of the patch and frequency of resonance was further modified with the help of E-shaped stub. The antenna has been fabricated using FR-4 substrate and the measured dual bands at 2.11 and 2.665 GHz are found in a close match with the simulated data. By placing a thin dielectric resonator of permittivity εr = 10.2 and thickness of 1.27 mm, two closely spaced narrow bands are obtained at 2.217 and 2.28 GHz. A novel metamaterial unit-cell having near-zero refractive index is designed and mounted above the dielectric resonator. This stack configuration generates triple narrow frequency band in the LTE 2 GHz spectrum range. The overall size of the proposed antenna is 20 × 25 mm2.

    关键词: triple band,split ring resonator,thin layer dielectric resonator,reflection coefficient,patch,unit-cell

    更新于2025-09-23 15:23:52

  • A CSRR-Based Sensor for Full Characterization of Magneto-Dielectric Materials

    摘要: In this paper, a novel complementary split-ring resonator (CSRR)-based sensor for full characterization of magneto-dielectric materials is proposed. In general, the operation of microwave resonance-based sensor hinges on the shift in the resonance frequency and the change in the quality factor of the loaded structure. However, both the electric permittivity and the magnetic permeability of the material under test (MUT) have similar effect on the response of the sensor that makes the simultaneous determination of the permittivity and permeability challenging. To remove this difficulty, the main idea behind this paper is to localize the highest intensity of the electric and magnetic fields in two separate zones. By the analysis of the measured resonance frequency and quality factor, the real and imaginary parts of the electric permittivity and the magnetic permeability of the MUT can be determined. Although the characterization of the permittivity and permeability of materials using split-ring resonator and CSRR-based sensors has been widely used, to the best of our knowledge, the full characterization of magneto-dielectric materials using a single sensor has not yet been reported in this paper. As a proof of concept, the sensor was fabricated and used to measure the permittivity and permeability of several materials. Strong agreement between the extracted values and the reference data was achieved.

    关键词: sensor,Complementary split ring resonator (CSRR),material characterization,split ring resonator (SRR),magneto-dielectric materials,permittivity and permeability

    更新于2025-09-23 15:23:52

  • Optimization of a parallel-plate RF probe for high resolution thin film imaging

    摘要: Choosing an MR probe with the correct dimensions and high sensitivity is critical for magnetic resonance imaging, especially high resolution thin film imaging. In this work, a parallel‐plate resonator has been optimized for strength and uniformity of the B1 magnetic field. The parallel‐plate resonator is designed for high resolution imaging in the direction perpendicular to the plates. The optimization process was undertaken through simulation with CST Micro Wave Studio, followed by experiment. A 400 μm capillary tube, filled with doped water, was used for testing the optimized probe in a 2.4 T magnet. It is shown that increasing the width of the copper leads connected to the plates increases the homogeneity of the B1 magnetic field by almost 90%. The best approach to increase the sensitivity and the homogeneity of the probe was to maintain the dimensions of the plates and copper leads but to add additional capacitors at the corners to distribute the current. This approach produces a 40% stronger B1 magnetic field and increases the homogeneity by almost 85%. The experimental B1 magnetic field of the parallel‐plate prototype agrees within 20% of the value found through simulation, for specified power. The experimental MRI results show that it is possible to achieve a nominal resolution of 10 μm between the plates for suitable samples using the optimized probe. The optimized parallel‐plate resonator, combined with a phase encode SE SPI method, may be used for high resolution studies of lithium‐ion transport in the electrolyte solution of lithium‐ion batteries.

    关键词: lithium-ion battery,optimization,MRI,parallel-plate resonator

    更新于2025-09-23 15:23:52

  • A new dual C-shaped rectangular dielectric resonator based antenna for wideband circularly polarized radiation

    摘要: This article presents a new dual C-shaped rectangular dielectric resonator (DR) based antenna for generation of wideband circularly polarized (CP) radiation. The proposed antenna comprises of a pair of C-shaped rectangular dielectric DR and a metal strip with a coaxial probe. By utilization of a metal strip at the side surface of C-shaped rectangular DR, the wideband CP radiation is achieved from the proposed dielectric resonator antenna (DRA). Fundamental orthogonal modes (TEx δ11 and TEy 1δ1) are excited using the rectangular DRA with a metal strip for the generation of CP fields. The proposed antenna with dual C-shaped rectangular CP DRA provides the measured ?10 dB reflection coefficient bandwidth of 30.07% (3.22 GHz-4.36 GHz) with measured 3-dB axial ratio bandwidth of 14.81% (3.25 GHz-3.77 GHz) at the boresight. The proposed antenna covers the useful Wi-MAX band.

    关键词: wideband,dielectric resonator antenna,coaxial probe,circularly polarized

    更新于2025-09-23 15:23:52

  • Bandwidth enhancing method using tri-ring resonator metamaterial for small devices

    摘要: Metamaterials are composite structures of the specific behavior for electromagnetic properties of permittivity, permeability, and refraction, which are not commonly found in regular materials. Metamaterial structure, which has negative value of permittivity and permeability that shows passband response in transmission line, where as if any of these two properties has opposite polarity then it shows stopband response. These behaviors of metamaterial are frequency dependent and have resonance for particular frequencies. At frequency resonance, the traditional metamaterials have narrow band response and to improve its frequency bandwidth, a method using tri-ring resonator is proposed with increasing number of order of resonator. The proposed metamaterial structure is simulated in full-wave simulator and MATLAB tool is used to analyze the properties of metamaterial structure from simulated S-parameter. Proposed technique gives flexibility to use the design for multiple application like, rejection filter for Bluetooth 2.4 GHz, Wi-Fi (2.4 and 5 GHz), WiMAX (2.5 and 3.4 GHz), and 5G (3.4-3.8 GHz).

    关键词: SRR,band rejection,split ring resonator,metamaterial,broadband

    更新于2025-09-23 15:23:52

  • Single Flip-Chip Packaged Dielectric Resonator Antenna for CMOS Terahertz Antenna Array Gain Enhancement

    摘要: A single dielectric resonator antenna (DRA) capable of enhancing the antenna gain of each element of a 2×2 THz antenna array realized in a 0.18-μm CMOS technology is proposed in this work. The DRA implemented in a low-cost integrated-passive-device (IPD) technology is flip-chip packaged onto the CMOS antenna array chip through low-loss gold bumps. By designing the DRA to work at the higher-order mode of TE3,δ,9, only single DRA instead of conventionally needing four DRAs is required to simultaneously improve the antenna gain of each element of the 2×2 antenna array. This not only simplifies the assembly process but it can also reduce the assembly cost. Moreover, the DRA can provide great antenna gain enhancement because of being made of high-resistivity silicon material and higher-order mode operation. The simulated antenna gain of each on-chip patch antenna of the 2×2 CMOS antenna array can be increased from 0.1 to 8.6 dBi at 339 GHz as the DRA is added. To characterize the proposed DRA, four identical power detectors (PDs) are designed and integrated with each element of the 2×2 THz antenna array, respectively. By measuring the voltage responsivity of each PD output, the characteristics of each antenna of the antenna array with the proposed DRA, including the gain enhancement level and radiation pattern, can be acquired. The measurement results follow well with the simulated ones, verifying the proposed DRA operation principle. The four PDs with the proposed DRA are also successfully employed to demonstrate a THz imaging system at 340 GHz. To the best of the authors’ knowledge, the proposed DRA is the one with the highest-order operation mode at THz frequencies reported thus far.

    关键词: Silicon,Flip-chip packaging,Terahertz,CMOS,Terahertz imaging system,Antenna,Higher-order mode,Power detector,Dielectric resonator antenna

    更新于2025-09-23 15:23:52

  • A Subwavelength Microstrip Resonator Based on Metamaterials

    摘要: A metamaterial-based subwavelength microstrip resonator with high quality factor and simple fabrication process was proposed. For the experimental result, a quality factor of about 70 was achieved when the length of the resonator was about one third of the wavelength. Firstly, the mu-negative metamaterial (MNM) and the epsilon-negative metamaterial (ENM) were implemented by loading only chip capacitors or only chip inductors onto the microstrip. The implementation process is simpler in comparison to the traditional implementation method of the MNM and the ENM based on the microstrip. Then, the transmission characteristics of the heterostructure constructed of the MNM and the ENM fabricated through the simple method were investigated and the results showed that a subwavelength microstrip resonator could be built by the MNM–ENM heterostructure. Moreover, the quality-factor enhancement of the subwavelength microstrip resonator based on the MNM–ENM heterostructure was also explored. The results showed that the quality factor could be notably boosted and increased by about 15 times for the experimental result of the sample owing to more intensive con?nement of the electromagnetic ?eld when the electromagnetically induced transparency-like metamaterial was introduced at the interface of the MNM–ENM heterostructure.

    关键词: resonator,quality factor,subwavelength,Metamaterials

    更新于2025-09-23 15:23:52