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- 摘要
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- 实验方案
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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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[IEEE 2018 IEEE PELS Workshop on Emerging Technologies: Wireless Power Transfer (WoW) - Montréal, QC, Canada (2018.6.3-2018.6.7)] 2018 IEEE PELS Workshop on Emerging Technologies: Wireless Power Transfer (Wow) - Modeling and Analysis Methods for the DWPT System Applicated in EVs Charging
摘要： The difficulty of modeling a dynamic wireless power transfer (DWPT) system for Electric Vehicles(EVs) charging is that its mutual inductance changes with the coil offset, so we have to build a dynamic model of the system. In this paper,we propose a modeling method by using equivalent circuit method and state space averaging.Moreover,based on the set of system parameters,comparing the results of the simulation experiment with the result of the model calculation.At last, the performance indexes of the system under the different buck duty cycle are observed. The simulation results of these indexes are also basically consistent with the model calculation results, which further verify the accuracy of the model.At the same time,we found that the selection of duty cycle has a great influence on the performance indexes.
关键词： Dynamic Wireless Power Transfer (DWPT),Equivalent Circuit Method,Electric Vehicles(EVs),State Space Averaging,Dynamic Model
更新于2025-09-23 15:23:52
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Thermal Influence on S22 kink behavior of a 0.15-μm gate length AlGaN/GaN/SiC HEMT for microwave applications
摘要： Thermal influence on S22 kink behavior has been carried out on a 0.15-μm gate length AlGaN/GaN/SiC high electron mobility transistor over a wide range of temperature. The size and the shape of the S22 kink effect in terms of biasing and temperature have been evaluated. The main finding is that S22 of the studied device is affected by two kinks: the first one appears at approximately 19 GHz and then the second one appears at about 43 GHz. The impact of the intrinsic circuit parameters on the S22 kink phenomena is inspected to assess their contribution. In addition, a new procedure is proposed to quantify this type of phenomenon by defining the kink area as the area between the two curves corresponding to S22 with and without the kink effect. The relevance of this study emerges from the fact that an exhaustive characterization of these anomalous phenomena can empower RF engineers to effectively take them into account for both modeling and design purposes.
关键词： scattering parameter measurements,and temperature,0.15-μm gate length GaN on SiC HEMT,equivalent circuit,two S22 kinks
更新于2025-09-23 15:23:52
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Equivalent-Circuit Model with Retarded Electromagnetic Coupling for Meta-Atoms of Wired Metallic Spheres
摘要： This paper describes the equivalent-circuit model of a metamaterial composed of conducting spheres and wires. This model involves electromagnetic coupling between the conductors, with retardation. The lumped-parameter equivalent circuit, which imports retardation to the electromagnetic coupling, is developed in this paper from Maxwell’s equation. Using the equivalent-circuit model, we clarify the relationship between the retardation and radiation loss; we theoretically demonstrate that the electromagnetic retardation in the near-field represents the radiation loss of the meta-atom in the far-field. Furthermore, this paper focuses on the retarded electromagnetic coupling between two meta-atoms; we estimate the changes in the resonant frequencies and the losses due to the distance between the two coupled meta-atoms. It is established that the dependence characteristics are significantly affected by electromagnetic retardation.
关键词： meta-atom,equivalent-circuit model,metamaterial,electromagnetic coupling,radiation,retardation
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Auckland (2018.8.5-2018.8.8)] 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Maximum efficiency analysis in wireless power transfer
摘要： The optimum design of loosely coupled transformer is the key technique in the wireless power transfer system (WPT). An improved magnetic model based on partial element equivalent circuit (PEEC) method is proposed in this paper. All parts of magnetic flux are divided into four categories: 1) flyback to topology; 2) resonant to topology; 3) quasi-resonant to topology; and 4) self-resonant to topology. As becomes clear from previous discussion, the converter topology used must be able to tolerate the minimum copper loss and minimum number of turns in given power transformer capability. In this method, the preferred parameters are coil shape and dimension, operating frequency, and coupling coefficient. The validity of the optimization algorithm is verified by experimental results.
关键词： reluctance model,parameter optimization,partial element equivalent circuit method,wireless power transfer,Prime-Mal
更新于2025-09-23 15:22:29
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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) - Low-Cost Simulation-Driven Design of Broadband Rectifiers for Ambient RF Energy Harvesting
摘要： A steady growth of ambient RF energy density associated with a rapid increase of the number of broadcasting devices stimulates the research on broadband harvesting circuits. Such circuits can be used as energy sources for low-power sensors or Internet-of-Things devices. On the other hand, dedicated design techniques for rectifiers are lacking which results in poor performance of existing circuits. Also, their design cost is high because it involves hybrid electromagnetic (EM) and harmonic balance (HB) simulations. In this work, we propose a novel design procedure for low-cost design of broadband rectifiers. The core component of the approach is a novel equivalent-circuit-based low-fidelity model which does not involve harmonic balance (HB) simulations. The model consists of a matching circuit loaded with the RF-to-DC converter block represented using the S-parameter matrix. The latter is obtained from a single HB simulation of the converter circuit. Inaccuracy of the model is reduced using appropriate correction techniques. At the first stage of the design process, the proposed model is optimized for minimization of the in-band reflection. At the second stage, a hybrid HB-EM-based tuning oriented towards maximization of the structure efficiency is carried out. The proposed approach is demonstrated using a novel broadband rectifier operating within 0.5 GHz to 3.5 GHz band. Numerical cost of the method is 80% lower compared to direct EM-HB- based optimization of the rectifier circuit.
关键词： broadband rectifiers,constrained optimization,simulation-driven design,surrogate-based optimization,equivalent circuit model
更新于2025-09-23 15:21:21
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Counter-intuitive junction temperature behavior in AlGaN-based deep-ultraviolet light-emitting diodes
摘要： The junction temperature, one of the major parameters that strongly affect the performance of light-emitting diodes (LEDs), increases during operation because of the power dissipated as heat within an LED device. Therefore, LED devices with poor characteristics are expected to have higher junction temperatures for the same driving conditions. In this study, an observation contrary to this expectation is presented: a deep-ultraviolet LED device with superior electrical characteristics shows a higher junction temperature at the same input electrical power than a device with poor characteristics. A simple equivalent circuit comprising a diode, a series resistor, and shunt components is employed to elucidate this counter-intuitive observation by considering the possible heat sources inside the LED device. It is found that the junction temperature is mainly dominated by the power dissipated at the diode instead of the other possible heat sources including the Joule heating effect of the resistive components.
关键词： junction temperature,Joule heating,AlGaN-based deep-ultraviolet light-emitting diodes,power dissipation,equivalent circuit
更新于2025-09-23 15:21:01
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[IEEE 2019 International Conference on Signal Processing and Communication (ICSC) - NOIDA, India (2019.3.7-2019.3.9)] 2019 International Conference on Signal Processing and Communication (ICSC) - Design and Implementation of Photonic Crystal Vertical Cavity Surface Emitting Laser
摘要： An injection-locked magnetron with an external oscillator was investigated to obtain the parameters of the equivalent circuit model. The magnetron was locked over the ratio of the input power to output power of ?26 dB and had the resonance characteristics of a parallel LCR circuit model. Increasing the input power caused the anti-resonance frequency to become the original frequency of the magnetron; the range of the locking frequency was wider because of the lower Q value. The phase noise of the locked magnetron of ?70 dBc at a 40-kHz offset was improved in comparison with an unlocked magnetron. The results show that an injection-locked magnetron with an external oscillator has great potential for obtaining a high power output.
关键词： frequency locking,injection-locked magnetron,Equivalent circuit model of magnetron
更新于2025-09-23 15:21:01
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Optimization of laser-patterning process and module design for transparent amorphous silicon thin-film module using thin OMO back electrode
摘要： Transparent hydrogenated amorphous silicon thin-film solar modules are fabricated using oxide-metal-oxide (OMO) electrodes as the back electrode for building-integrated photovoltaic applications. The outer aluminum-doped zinc oxide and inner silver layers constitute a thin OMO electrode (~110 nm thick), exhibiting a sheet resistance of 6.8 Ω/□ and an average transmittance of ~88% in the visible range of 400–800 nm. The external quantum efficiency and average transmittance of the cell were investigated for the absorber-layer thickness using the finite-difference time-domain method, and it was found that the optical loss in the cell was mainly due to the absorption of the front electrode in the ultra-violet region and free-carrier absorption of the OMO in the infrared region. Fabrication issues are introduced for a 532 nm short-pulse high-power laser patterning process for transparent modules with thin OMO electrodes. Optimization of the laser power for the P2 and P3 laser processes is demonstrated by observing the profiles and measuring the shunt resistance of the laser-patterned edges. Furthermore, the cell width is optimized based on an equivalent circuit model using PSpice simulation. The highest module efficiency and average transparency achieved in the range of 500–800 nm were 5.6% and 15.2%, respectively. The short-circuit current density, fill factor, and open-circuit voltage per cell of the module were found to be 10.8 mA/cm2, 62.7%, and 0.830 V, respectively.
关键词： Laser patterning,Transparent amorphous silicon photovoltaic,Equivalent circuit,Building integrated photovoltaic,Cell geometry,Oxide-metal-oxide electrode
更新于2025-09-23 15:21:01
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1-D Metal-Dielectric-Metal Grating Structure as an Ultra-Narrowband Perfect Plasmonic Absorber in the Visible and Its Application in Glucose Detection
摘要： The need for an easy to fabricate perfect and narrowband light absorber in the visible range of electromagnetic (EM) spectrum has always been in demand for many scientific and device applications. Here, we propose a metal-dielectric-metal (MDM) 1-D grating plasmonic structure as a perfect narrow band light absorber in the visible and its application in glucose detection. The proposed structure consists of a 1- D grating of gold on the top of a dielectric layer on a gold film. Optimization for dielectric grating index (n), grating thickness (t), grating width (W), and grating period (P) has been done to improve the performance of plasmonic structure by calculating its quality factor and figure-of-merit (FOM). The optimized plasmonic structure behaves as a perfect narrowband light absorber. The flexibility to work at a specific wavelength is also offered by the proposed structure through an appropriate selection of the geometrical parameters and refractive index of the dielectric grating. The equivalent RC model is used to understand different components of the proposed structure on the optical response. The absorption response of the structure is invariant to the incident angle. Moreover, the calculated absorbance of the proposed plasmonic structure is ~ 100% with a narrow full-width half maxima (FWHM) of ~ 2.8 nm. We have numerically demonstrated a potential application of the proposed MDM absorber as a plasmonic glucose sensor in the visible range with detection sensitivity in the range of 140 to 195 nm/RIU.
关键词： Metal-dielectric-metal,Plasmons,Glucose detection,Optical sensors,Optical detectors,LC equivalent circuit
更新于2025-09-23 15:21:01