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- 2018
- arbitrary coupling coefficients
- Dielectric resonator
- filtering
- coupler
- filtering balun
- dual-band
- dual-mode dielectric resonator (DR)
- Electronic Science and Technology
- Nantong University
- Sun Yat-Sen University
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Investigation of Fe-doped room temperature dilute magnetic ZnO semiconductors
摘要： Different ceramics sample of Zn1-xFexO (ZFO) series have been sintered by solid state reaction method. Single phase polycrystalline Fe-doped ZnO sample with hexagonal wurtzite structure has been obtained with x < 0.03 mol. Segregation of Fe and/or its oxides have not been found in the XRD patterns. A weak secondary phase of ZnFe2O4 has been detected with x ≥ 0.03 mol. Presence of Ohmic conductivity has been detected in the dielectric property analysis and the reasons for this Maxwell-Wagner-Sillars (MWS) relaxation has been explained by the grain boundary barrier defect (GBBD) process. The obtained shift of diamagnetic behavior of pure ZnO samples to para-magnetic for ZFO samples has been established with the defect and impurity structure. The band gap energy for ZFO samples has been calculated between 2.85 eV to 3.15 eV. The results indicate the potential use of Fe doped ZnO ceramics in high frequency device applications.
关键词： Spintronics,XRD,Hysteresis loops,Dilute magnetic semiconductor,Dielectric constant,Optical property
更新于2025-10-22 19:40:53
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Approach to Inversion Design of Dielectric Material Based on the First-Principle
摘要： The ?rst-principle is an e?ective method for the material property calculation. One inversion design idea of dielectric material based on the ?rst-principle was put forward. In this kind of material design thought, the speci?c demanded dielectric property of material is the starting point of the whole design course. The atomic structure characteristic of the material is solved using the inversion model based on the ?rst-principle. And the key issues needing researching were discussed, these problems were quantized structure of electromagnetic and optic ?eld, the quantized polarization theory of dielectric material, the uniform calculation method of dielectric property and the dielectric material inversion model.
关键词： Dielectric material,First-principle,Dielectric property,Inversion design
更新于2025-09-23 15:23:52
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[IEEE 2018 18th International Symposium on Antenna Technology and Applied Electromagnetics (ANTEM) - Waterloo, ON (2018.8.19-2018.8.22)] 2018 18th International Symposium on Antenna Technology and Applied Electromagnetics (ANTEM) - Cavity Perturbation Technique to Characterize Dielectric Materials at Ka-band
摘要： The characterization of permittivity and dielectric loss of dielectric materials using a perturbation technique is conducted in simulation. The working frequency of this technique has been extended to the Ka-band. Simulation results demonstrate this perturbation technique is suitable for characterization of high permittivity dielectric materials for mm-wave and maintains good accuracy.
关键词： dielectric loss measurement,permittivity measurement,cavity perturbation technique,dielectric materials,Ka-band
更新于2025-09-23 15:23:52
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Reconfigurable Near-field Enhancement with Hybrid Metal-Dielectric Oligomers
摘要： Tailoring of the near-field properties of the nanostructures is a significant task for the control of radiation of nanoscale light sources as well as for sensing applications. Generally, this task is solved in plasmonic oligomers on the fabrication step by the choice of geometry or by controlling the excitation light during the experiments. Here, the pronounced modification of the near-field pattern in hybrid gold-silicon oligomers by femtosecond laser reshaping by visualizing it with aperture-type near-field optical microscope is demonstrated. This effect correlates with a moderate red-shift of the broadband magnetic dipole resonance of the structure that occurs upon reshaping the gold component of the oligomers. The proposed all-optical near-field reconfiguration approach makes hybrid oligomers a promising platform for on-demand engineering of local field enhancement in metadevices for data recording and sensing.
关键词： near-field tuning,metal-dielectric oligomers,femtosecond laser reconfiguration
更新于2025-09-23 15:23:52
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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
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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
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Design and characterization of the double-layered defected ground structure transmission line with less radiation loss
摘要： A double-layered DGS transmission line is proposed with a smaller DGS size and less radiation loss. Changing the air boundary to a dielectric boundary reduces the effective electric length at the DGS aperture area. An equivalent circuit model is introduced to analyze the DGS transmission line and the resonator circuit designs. Due to the increase in the effective dielectric constant, the proposed structure can be realized with less sensitivity to metallic environments. From the experimental results, the proposed double-layered DGS can achieve a reduction of 90.1% in size and insensitivity at up to 5 mm of separation from the DGS aperture to the metallic plate.
关键词： equivalent circuit models,effective dielectric constants,radiation loss,size reduction,defected ground structures
更新于2025-09-23 15:23:52
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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
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Polarization and acoustic properties of barium-modified lead-free potassium–sodium niobate ceramics
摘要： Results of polarization and polarization switching in samples prepared by solid phase synthesis of the (1-х)(K0.5Na0.5)(Nb0.93Sb0.07)O3–xBaTiO3 + 0.5mol%MnO2 system at x = 0.01, 0.02, and 0.04 (KNNS7–xBT) studied over a wide range of temperatures are reported. The observed features of the dielectric nonlinearity at the ferroelectric and structural phase transitions in the materials are described. The dielectric response data of the samples of different contents of the admixture in the KNNS7–xВT ceramics are compared with the behaviour of their elastic properties.
关键词： dielectric permittivity,polarization,solid solutions,elastic properties,relaxors,ferroelectrics,ceramics
更新于2025-09-23 15:23:52
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Novel solid polymer electrolyte based on PMMA:CH3COOLi effect of salt concentration on optical and conductivity studies
摘要： Novel solid polymer electrolyte (SPE) films based on poly(methyl methacrylate) (PMMA) and lithium acetate (CH3COOLi) with different weight ratios of PMMA:CH3COOLi wt% (60:40, 70:30, 80:20 wt%) were prepared by solution casting technique. XRD analysis confirmed the amorphous nature of Li–PMMA SPE films. FTIR analysis revealed the structural changes in polymer by complexation with Li salt. From the optical absorbance studies, the value of lowest energy band gap was found to be 3.06 eV for the composition, PMMA:CH3COOLi (60:40 wt%). From AC impedance studies, the highest value of ionic conductivity 8.21 × 10?5 S/cm at 303 K for the SPE film PMMA:CH3COOLi (60:40 wt%) is observed compared to the reported literature. From the results of Li–PMMA SPE film with high ionic conductivity, it is a promising material for the application of solid-state battery.
关键词： Band gap,Ionic conductivity,Dielectric measurements,Li–PMMA SPE
更新于2025-09-23 15:23:52