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Showing papers on "Equivalent circuit published in 2006"


Journal ArticleDOI
TL;DR: In this article, the principle of dye-sensitized solar cells (DSCs) in terms of a new physics-based equivalent circuit model was discussed, and the highest efficiency scores of 10.4% and 10.8% (aperture illumination area 1.004 cm2 and 0.2227 cm2, respectively) were confirmed by a public test center.
Abstract: The present paper discusses the principle of dye-sensitized solar cells (DSCs) in terms of a new physics-based equivalent circuit model. This model is proposed following analysis by electrochemical impedance spectroscopy of the voltage dependence of the internal resistance elements of DSCs. The influence of these elements upon cell performance in areas such as short circuit current density (JSC), open circuit voltage (VOC) and fill factor (FF) was examined based on the equivalent circuit. It was demonstrated that the haze factor of TiO2 electrodes is a useful index when fabricating light-confined TiO2 electrodes to improve JSC, and that blocking the TiO2 surface with molecules is an effective way of reducing interfacial charge recombination at the TiO2 surface and of improving shunt resistance and VOC. FF was also improved by reduction of the internal series resistance, which is composed of the following three elements: the redox reaction resistance at the platinum counter electrode, the resistance of carrier transport by ions in the electrolyte, and resistance due to the sheet resistance of the transparent conducting oxide. Finally, the highest efficiency scores of 10.4% and 10.8% (aperture illumination area 1.004 cm2 and 0.2227 cm2, respectively) were confirmed by a public test center.

388 citations


Journal ArticleDOI
TL;DR: In this article, the optimization of various parameters which govern the behavior of polymer-based and organic photovoltaic cells is discussed, and deviations from optimal values and their effects on the current-voltage characteristics are discussed.
Abstract: In this paper we discuss the optimization of various parameters which govern the behaviour of polymer based and organic photovoltaic cells. General mechanisms leading to the generation of charge carriers and the related loss factors are detailed. Theoretical electrical parameters for bilayer and interpenetrating networks of donors and acceptors (open circuit voltages) are established along with current versus voltage characteristics. An equivalent circuit to a solar cell, considering the effects of shunt resistance across the whole layer, is elaborated. After modelling optical interference and its effects on the photocurrent spectrum, orders of magnitude of the required parameters are established for an efficient solar cell. Deviations from optimal values and their effects on the current–voltage characteristics are discussed. Ageing and degradation effects, and calculations demonstrating the necessary photophysical requirements to achieve long-term stable devices are presented. Copyright © 2006 Society of Chemical Industry

382 citations


Journal ArticleDOI
TL;DR: In this paper, the authors show that equivalent circuits offer a qualitative and even quantitative simple explanation for the behavior of various types of left-handed (or negative-index) metamaterials and apply this unifying circuit approach in accounting for the features and in optimizing the structure employing parallel metallic bars on the two sides of a dielectric film.
Abstract: We show that equivalent circuits offer a qualitative and even quantitative simple explanation for the behavior of various types of left-handed (or negative-index) metamaterials. This allows us to optimize design features and parameters while avoiding trial and error simulations or fabrications. In particular, we apply this unifying circuit approach in accounting for the features and in optimizing the structure employing parallel metallic bars on the two sides of a dielectric film.

354 citations


Book
01 Jan 2006
TL;DR: In this article, the authors present a short history of the EKV most model and its application in IC design, and present an extended version of the model with an extended charge-based model.
Abstract: Foreword. Preface. List of Symbols. 1. Introduction. 1.1 The Importance of Device Modeling for IC Design. 1.2 A Short History of the EKV MOST Model. 1.3 The Book Structure. PART I: THE BASIC LONG-CHANNELINTRINSIC CHARGE-BASED MODEL. 2. Introduction. 2.1 The N-channel Transistor Structure. 2.2 Definition of charges, current, potential and electric fields. 2.3 Transistor symbol and P-channel transistor. 3. The Basic Charge Model. 3.1 Poisson's Equation and Gradual Channel Approximation. 3.2 Surface potential as a Function of Gate Voltage. 3.3 Gate Capacitance. 3.4 Charge Sheet Approximation. 3.5 Density of Mobile Inverted Charge. 3.6 Charge-Potential Linearization. 4. Static Drain Current. 4.1 Drain Current Expression. 4.2 Forward and Reverse Current Components. 4.3 Modes of Operation. 4.4 Model of Drain Current Based on Charge Linearization. 4.5 Fundamental Property: Validity and Application. 4.6 Channel Length Modulation. 5. The Small-Signal Model. 5.1 The Static Small-Signal Model. 5.2 A General Non-Quasi-Static Small-Signal Model. 5.3 The Quasi-Static Dynamic Small-Signal Model. 6. The Noise Model. 6.1 Noise Calculation Methods. 6.2 Low-Frequency Channel Thermal Noise. 6.3 Flicker Noise. 6.4 Appendices. Appendix : The Nyquist and Bode Theorems. Appendix : General Noise Expression. 7. Temperature Effects and Matching. 7.1 Introduction. 7.2 Temperature Effects. PART II: THE EXTENDED CHARGE-BASED MODEL. 8. Non-Ideal Effects Related to the Vertical Dimension. 8.1 Introduction. 8.2 Mobility Reduction Due to the Vertical Field. 8.3 Non-Uniform Vertical Doping. 8.4 Polysilicon Depletion. 8.4.1 Definition of the Effect. 8.5 Band Gap Widening. 8.6 Gate Leakage Current. 9. Short-Channel Effects. 9.1 Velocity Saturation. 9.2 Channel Length Modulation. 9.3 Drain Induced Barrier Lowering. 9.4 Short-Channel Thermal Noise Model. 10. The Extrinsic Model. 10.1 Extrinsic Part of the Device. 10.2 Access Resistances. 10.3 Overlap Regions. 10.4 Source and Drain Junctions. 10.5 Extrinsic Noise Sources. PART III: THE HIGH-FREQUENCY MODEL. 11. Equivalent Circuit at RF. 11.1 RF MOS Transistor Structure and Layout. 11.2 What Changes at RF?. 11.3 Transistor Figures of Merit. 11.4 Equivalent Circuit at RF. 12. The Small-Signal Model at RF. 12.1 The Equivalent Small-Signal Circuit at RF. 12.2 Y-Parameters Analysis. 12.3 The Large-Signal Model at RF. 13. The Noise Model at RF. 13.1 The HF Noise Parameters. 13.2 The High-Frequency Thermal Noise Model. 13.3 HF Noise Parameters of a Common-Source Amplifier. References. Index.

307 citations


Journal ArticleDOI
TL;DR: It is shown that equivalent circuits offer a qualitative and even quantitative simple explanation for the behavior of various types of left-handed (or negative-index) metamaterials and this approach is applied in accounting for the features and in optimizing the structure employing parallel metallic bars on the two sides of a dielectric film.
Abstract: In this letter we show that equivalent circuits offer a qualitative and even quantitative simple explanation for the behavior of various types of left-handed (or negative index) meta-materials. This allows us to optimize design features and parameters, while avoiding trial and error simulations or fabrications. In particular we apply this unifying circuit approach in accounting for the features and in optimizing the structure employing parallel metallic bars on the two sides of a dielectric film.

301 citations


Journal ArticleDOI
TL;DR: In this paper, an impedance model of the proton exchange membrane fuel cell stack (PEMFCS) is proposed to evaluate the effects of ripple currents generated by the power-conditioning unit.

232 citations


Journal ArticleDOI
TL;DR: A neural network based approach for improving the accuracy of the electrical equivalent circuit of a photovoltaic module, which shows higher accuracy than the conventional model for all operating conditions.

198 citations


Journal ArticleDOI
TL;DR: The impedance obtained in this study described the ion-exchange membrane system well, and made it possible to confirm the electroconvective effects in the over LCD region.

173 citations


Journal ArticleDOI
TL;DR: In this article, the series resistance of an InGaP/InGaAs/Ge triple-junction solar cell was evaluated in detail and the optimization of cell designs was performed focusing on series resistance and cell current in order to realize high-efficiency concentrator cells.

168 citations


Journal ArticleDOI
11 Dec 2006
TL;DR: In this paper, a three-phase induction motor model which represents the motor behavior over a wide range of frequencies from 10 Hz to 10 MHz is presented, and the model is universal in the sense that common mode, differential mode and bearing circuit models are combined into one three phase equivalent circuit model.
Abstract: A three-phase induction motor model which represents the motor behavior over a wide range of frequencies from 10 Hz ? 10 MHz is presented in this paper. The model is universal in the sense that common mode, differential mode and bearing circuit models are combined into one three-phase equivalent circuit model. The proposed model is basically an extension of the low frequency IEEE Standard 112 circuit model. The proposed model was simulated and verified experimentally with results presented.

164 citations


Journal ArticleDOI
TL;DR: The intrinsic failure mechanisms and reliability models of state-of-the-art MOSFETs are reviewed and a new approach for accurately predicting circuit reliability and failure rate from the system point of view is proposed.

Journal ArticleDOI
TL;DR: In this article, the authors focused on the determination and analysis of an accurate small-signal equivalent circuit for gallium-nitride high electron-mobility transistors under different bias conditions.
Abstract: This paper focuses on the determination and analysis of an accurate small-signal equivalent circuit for gallium-nitride high electron-mobility transistors under different bias conditions. Our experimental results show that a channel capacitance has to be added to the conventional forward "cold" model for modeling the device-under-test. The validity of the proposed extraction procedure has been verified by the very good agreement between simulated and measured scattering parameters up to 50 GHz

Journal ArticleDOI
TL;DR: In this article, a four-branch hybrid with mixed distributed and lumped distributed elements was designed and tested for wide-band branch-line couplers, which achieved a fractional bandwidth larger than 56% at the center frequency of 2 GHz.
Abstract: Wide-band branch-line couplers are designed and tested. The proposed couplers feature compact size on a single circuit layer structure without via-holes. For the broad-band property and cost effectiveness, we have designed a four-branch hybrid with mixed distributed and lumped distributed elements. Analysis on the equivalent circuits was performed carefully in order to obtain a sufficient bandwidth with reduced design area. The fabricated hybrids have the fractional bandwidth larger than 56% at the center frequency of 2 GHz. They also show size reduction up to 55.2% compared with the conventional design method.

Journal ArticleDOI
TL;DR: In this paper, the design, performance analysis, fabrication, and experimental results of a three-phase, three-stack permanent magnet transverse flux motor with a soft magnetic composite stator core are presented.
Abstract: This paper reports the design, performance analysis, fabrication, and experimental results of a three-phase, three-stack permanent magnet transverse flux motor with a soft magnetic composite stator core, which was designed to take advantage of the unique properties of the new material. Parameter computations by finite element analysis of the magnetic field and performance prediction by the equivalent electric circuit are discussed. To validate the simulation, a prototype motor has been fabricated and operated with a sensorless, brushless direct coupler drive scheme. The experimental results are thoroughly presented and agree with the theoretical calculations very well.

Journal ArticleDOI
TL;DR: The nanoscale devices described herein were characterized using impedance spectroscopy, enabling the development of an equivalent circuit and the proposed methodology of nanocontacting and measurements can be easily applied to other nanowires and nanometre-sized materials.
Abstract: Two- and four-probe electrical measurements on individual tin oxide (SnO2) nanowires were performed to evaluate their conductivity and contact resistance. Electrical contacts between the nanowires and the microelectrodes were achieved with the help of an electron- and ion-beam-assisted direct-write nanolithography process. High contact resistance values and the nonlinear current–bias (I–V) characteristics of some of these devices observed in two-probe measurements can be explained by the existence of back-to-back Schottky barriers arising from the platinum–nanowire contacts. The nanoscale devices described herein were characterized using impedance spectroscopy, enabling the development of an equivalent circuit. The proposed methodology of nanocontacting and measurements can be easily applied to other nanowires and nanometre-sized materials.

Journal ArticleDOI
TL;DR: In this paper, a digital 5-bit phase shifter at Ku-band is presented, which is implemented with 0.18-mum RFCMOS technology, and it exhibits broad-band characteristics.
Abstract: A digital 5-bit phase shifter at Ku-band is presented, which is implemented with 0.18-mum RFCMOS technology. n-MOSFET switches and top metal microstrip lines with a first-metal ground allow the phase shifter to have small insertion losses. The proposed 90deg phase shifter utilizing a parallel resonator exhibits broad-band characteristics. All of the circuit components are derived to obtain a minimum phase variation at the operation frequency band. A bridged-T type phase shifter is also analyzed in view of parallel resonance using an ideal equivalent-circuit model. The conditions of the circuit elements are derived in an analytic form, which are used to obtain the broad-band phase characteristics. The fabricated 5-bit phase shifter demonstrates an overall rms phase error less than 12deg from 9 to 15 GHz. Insertion losses of 14.5 dB plusmn 0.5 dB and return losses less than 14 dB are obtained for 32 states at 12 GHz. The proposed 90deg phase shifter has performed a phase shift of 92.3degplusmn3.2deg over 9-15 GHz

Journal ArticleDOI
TL;DR: In this article, an iterative technique for the design of planar coupled-resonator microwave filters, which exploits initial information on the equivalent circuit elements within the space-mapping technique, is presented.
Abstract: This paper presents an iterative technique for the design of planar coupled-resonator microwave filters, which exploits initial information on the equivalent circuit elements within the space-mapping technique. To accelerate the convergence of the design process, information on the dependence of the elements of the equivalent circuit on adjustable geometrical and physical parameters, which is available from the initial design step, is used. The technique is applied to design harmonic-reject planar filters. Results from applications to fourth- and sixth-order filters show that the successful designs are achieved with at most two iterations. A sixth-order harmonic-reject filter is then fabricated and measured.

Journal ArticleDOI
TL;DR: In this article, the authors proposed a closed-form expression for the parasitics associated with the interconnects of the decoupling capacitors of a dc power distribution network.
Abstract: Investigation of a dc power delivery network, consisting of a multilayer PCB using area fills for power and return, involves the distributed behavior of the power/ground planes and the parasitics associated with the lumped components mounted on it Full-wave methods are often employed to study the power integrity problem While full-wave methods can be accurate, they are time and memory consuming The cavity model of a rectangular structure has previously been employed to efficiently analyze the simultaneous switching noise (SSN) in the power distribution network However, a large number of modes in the cavity model are needed to accurately simulate the impedance associated with the vias, leading to computational inefficiency A fast approach is detailed herein to accelerate calculation of the summation associated with the higher-order modes Closed-form expressions for the parasitics associated with the interconnects of the decoupling capacitors are also introduced Combining the fast calculation of the cavity models of regularly shaped planar circuits, a segmentation method, and closed-form expressions for the parasitics, an efficient approach is proposed herein to analyze an arbitrary shaped power distribution network While it may take many hours for a full-wave method to do a single simulation, the proposed method can generally perform the simulation with good accuracy in several minutes Another advantage of the proposed method is that a SPICE equivalent circuit of the power distribution network can be derived This allows both frequency and transient responses to be done with SPICE simulation

Journal ArticleDOI
TL;DR: In this paper, a general mathematical model of a five-phase induction machine including the effects of higher space and time harmonics in the air gap field is presented, and results are compared with values obtained by finite element analysis and measurements.
Abstract: This paper presents a general mathematical model of a five-phase induction machine including the effects of higher space and time harmonics in the air gap field. These harmonic waves play a decisive role in the behavior of machines with more than three phases. Mathematical expressions for the calculation of the self and mutual inductances are presented, and results are compared with values obtained by finite element analysis and measurements. Based on the air gap field distribution produced by the stator and rotor, all the field harmonics are included in a direct and simple way in the self-inductances. The mutual inductances are obtained from a Fourier series description of the air gap field, resulting in a different inductance for each harmonic field. The machine equations are then simplified using coordinate transformations, which result in equivalent d-q models and equivalent circuits for given harmonic groups. In their final form, the equations are appropriated for the simulation of the machine behavior and developing new control strategies including higher space and time harmonics. Finally, practical results of a prototype machine are compared with simulations demonstrating the accuracy of the model

Journal ArticleDOI
TL;DR: In this article, an analytical two-port, lumped-element model of a piezoelectric composite circular plate is presented, where the individual components of a unimorph transducer are modeled as lumped elements of an equivalent electrical circuit using conjugate power variables, and the transverse static deflection field as a function of pressure and voltage loading is determined to synthesize the twoport dynamic model.
Abstract: This paper presents an analytical two-port, lumped-element model of a piezoelectric composite circular plate. In particular, the individual components of a piezoelectric unimorph transducer are modeled as lumped elements of an equivalent electrical circuit using conjugate power variables. The transverse static deflection field as a function of pressure and voltage loading is determined to synthesize the two-port dynamic model. Classical laminated plate theory is used to derive the equations of equilibrium for clamped circular laminated plates containing one or more piezoelectric layers. A closed-form solution is obtained for a unimorph device in which the diameter of the piezoelectric layer is less than that of the shim. Methods to estimate the model parameters are discussed, and model verification via finite-element analyses and experiments is presented. The results indicate that the resulting lumped-element model provides a reasonable prediction (within 3%) of the measured response to voltage loading and the natural frequency, thus enabling design optimization of unimorph piezoelectric transducers.

Journal ArticleDOI
TL;DR: In this paper, the authors demonstrate a methodology that enables concurrent extraction of leaky-wave attenuation constants and Brillouin diagrams of periodic structures, through the FDTD simulation of a unit cell.
Abstract: The determination of the attenuation constants of periodic leaky-wave structures via the finite-difference time-domain (FDTD) method has been pursued so far via the simulation of a number of unit cells that is large enough to guarantee the convergence of the computed value. On the other hand, Brillouin diagrams of periodic structures can be readily extracted via the simulation of a single unit cell, terminated in periodic boundary conditions. This paper demonstrates a methodology that enables the concurrent extraction of leaky-wave attenuation constants and Brillouin diagrams of periodic structures, through the FDTD simulation of a unit cell. The proposed methodology is first validated and then employed to model leaky-wave radiation from a two-dimensional negative-refractive-index transmission-line (NRI-TL) medium. Apart from evaluating the characteristics of forward and backward leaky-wave radiation from such a medium, a lumped-element macro-model, with element values determined from the FDTD simulation, is extracted. The FDTD analysis, combined with this equivalent circuit, is used to investigate theoretically the possibility of the NRI-TL medium, as a leaky-wave antenna, to achieve continuous scanning from backward to forward end-fire and broadside radiation.

Journal ArticleDOI
TL;DR: In this paper, an active EMI filter (AEF) for integrated power electronics module (IPEM) is proposed, where large passive filter is replaced by small passive components and active op-amp circuit.
Abstract: In recent years, there has been considerable interest in the development and applications of active electromagnetic interference (EMI) filters. An active EMI filter (AEF) for integrated power electronics module (IPEM) is proposed in this paper, where large passive EMI filter is replaced by small passive components and active op-amp circuit. The technique is appropriated when improved attenuation is required at relatively low frequencies and the high-frequency filtering requirements are easily met. The effectiveness of the proposed circuit has been verified by experimental results. It is demonstrated that the proposed approach is most effective in a case where it is desirable to minimize the amount of passive components in the filter

Journal ArticleDOI
TL;DR: A new framework for linear active circuits that can encompass both circuit analysis and synthesis is proposed, based on a definition of port equivalence for admittance matrices, which is extended to cover circuits with ideal active elements through the introduction of a special type of limit-variable called the infinity-variable.
Abstract: This paper proposes a new framework for linear active circuits that can encompass both circuit analysis and synthesis. The framework is based on a definition of port equivalence for admittance matrices. This is extended to cover circuits with ideal active elements through the introduction of a special type of limit-variable called the infinity-variable (infin-variable). A theorem is developed for matrices containing infin-variables that may be utilized in both circuit analysis and synthesis. The notation developed in this framework can describe nonideal elements as well as ideal elements and therefore the framework encompasses systematic circuit modeling

Journal ArticleDOI
19 Jun 2006
TL;DR: A new general equivalent circuit approach for a thin frequency selective structure (FSS) that is valid for any angle of incidence and for any lattices, provides a better understanding of how a particular FSS structure operates and potentially allows the synthesis of FSS by optimisation of circuit parameters.
Abstract: A new general equivalent circuit approach for a thin frequency selective structure (FSS) has been proposed. The method exhibits higher accuracy compared with conventional equivalent circuit approaches, is valid for any angle of incidence and for any lattices, provides a better understanding of how a particular FSS structure operates and potentially allows the synthesis of FSS by optimisation of circuit parameters. In addition its performance is much faster than techniques employing rigorous solutions. A theoretical study of the method has been undertaken using ring slot and rectangular slot elements as test elements for the analysis. Very good agreement in comparison with computational electromagnetics (CEM) software and rigorous methods has been obtained.

Proceedings ArticleDOI
Chunghyun Ryu1, Ji Wang Lee1, Hyein Lee1, Kwangyong Lee2, Tae-Sung Oh2, Joungho Kim1 
05 Sep 2006
TL;DR: In this paper, an equivalent circuit model of through wafer via which has height of 90?m and diameter of 75?m was developed based on the physical configuration of through-wafer via.
Abstract: In this paper, we propose an equivalent circuit model of through wafer via which has height of 90 ?m and diameter of 75 ?m. The equivalent circuit model composed of RLCG components is developed based on the physical configuration of through wafer via. Then, the parameter values of the equivalent circuit model are fitted to the measured s-parameters up to 20GHz by parameter optimization method. The proposed model shows through wafer via is dominantly characterized by the capacitance of thin oxide around the via and resistive characteristic of lossy silicon substrate. From simulated TDR/TDT and eye-diagram waveforms of the proposed equivalent circuit model, it is found that parasitic effects of the via cause slow rising time of a signal during transmission of the signal to the through wafer via. However, unlike to the most cases, the slow rising time of through wafer via will not degrade signal integrity severely. At last, we show the effect of dimension of through wafer via on performance of signal transmission using 3-D full wave simulation.

Journal ArticleDOI
TL;DR: This paper demonstrates that only with careful thermal modeling assumptions and appropriate choices for grid hierarchy, MG operators, and smoothing steps across grid points can a full-chip thermal problem be accurately and efficiently analyzed.
Abstract: The ever-increasing power consumption and packaging density of integrated systems creates on-chip temperatures and gradients that can have a substantial impact on performance and reliability. While it is conceptually understood that a thermal equivalent circuit can be constructed to characterize the temperature gradients across the chip, direct and iterative solutions of the corresponding three-dimensional (3-D) equations are often intractable for a full-chip analysis. Integrated circuit (IC)-specific multigrid (MG) techniques for fast chip level thermal steady-state and transient simulation are proposed. This approach avoids an explicit construction of the matrix problem that is intractable for most full-chip problems. Specific MG treatments are proposed to cope with the strong anisotropy of the full-chip thermal problem that is created by the vast difference in material thermal properties and chip geometries. Importantly, this paper demonstrates that only with careful thermal modeling assumptions and appropriate choices for grid hierarchy, MG operators, and smoothing steps across grid points can a full-chip thermal problem be accurately and efficiently analyzed. This paper further speeds up the large thermal transient simulations by incorporating reduced-order thermal models that can be efficiently extracted under the same MG framework. The experiments carried out in this work have shown that the proposed methodology provides sufficient efficiency in both runtime and memory usage

Journal ArticleDOI
TL;DR: In this article, the problem of discontinuities in coupled-stripline 3-dB directional couplers, phase shifters, and magic-T's, regarding the connections of coupled and terminating signal lines, has been comprehensively investigated for the first time.
Abstract: The problem of discontinuities in coupled-stripline 3-dB directional couplers, phase shifters, and magic-T's, regarding the connections of coupled and terminating signal lines, has been comprehensively investigated for the first time. The proposed equivalent circuit of these discontinuities, of which parameters can be computed in a process of fitting curves of the circuit and electromagnetic analyses, has been used for accurate modeling of coupled-stripline circuits. It has been shown that parasitic reactances, which result from connections of signal and coupled lines, severely deteriorate the return losses and the isolation of such circuits, and that these discontinuity effects can be substantially reduced by connecting compensating shunt capacitances to both coupled and signal lines. Results of measurements carried out for various designed and manufactured coupled-line circuits are most promising and prove the efficiency of the proposed compensation technique. This paper describes the technique of capacitive compensation of discontinuity effects in single-section coupled-line circuits

Journal ArticleDOI
TL;DR: In this paper, the authors proposed a new continuum electromechanical model to understand and predict the electrical/mechanical behavior of an ionic polymer-metal composites (IMC).
Abstract: Biomedical engineering applications of ionic polymer–metal composites such as motion devices for endoscopy, pumps, valves, catheter navigation mechanisms and spinal pressure sensors make it important to properly model IPMCs for engineering design. In particular, IPMC continuum models and their electric equivalent circuit representation are critical to a more efficient design of IPMC devices. In this paper, we propose a new continuum electromechanical model to understand and predict the electrical/mechanical behavior of the IPMC. An IPMC lumped-parameter circuit is derived from its continuum model to predict the relationship between its voltage and current signals. Although based on previous works of Shahinpoor and Nemat-Nasser, our model was derived on a macroscopic level, the water effects were assumed negligible when compared with the electrical effects of mobile ions for the IPMC motion, the model parameters were clearly identified in their physical meaning, and an equivalent-circuit IPMC model was determined from the established continuum electromechanical model. Experiments are done with two IPMC pieces having different dimensions, which were previously immersed in a sodium solution. The IPMCs are current driven, the transverse displacement and voltage signals being measured for different current values, avoiding the water electrolysis phenomenon. Simulations using the analytic models derived are compared with the experimental results and they are found to predict the electrical and mechanical relations very accurately.

Journal ArticleDOI
TL;DR: In this article, a new modeling technique for plasmon-based metallic nanoparticles under the influence of an electromagnetic field is presented, which approximates the coefficients of the admittance rational function.
Abstract: In this paper, we present a new modeling technique for plasmon-based metallic nanoparticles under the influence of an electromagnetic field. The model approximates the coefficients of the admittance rational function. The proposed model utilizes spherical wave functions to describe the field and it provides an equivalent ladder-form RLC realization. Simulation results show that our model matches very closely with the exact solution. Our newly developed model can be used as a basic building block to develop an equivalent circuit model for metallic nanoparticle-based plasmonic waveguides

Journal ArticleDOI
TL;DR: This brief describes this ringing phenomenon and the use of an RC-RCD clamp circuit for damping the clamp diode's oscillation, capable for improving a flyback converter's power ratio.
Abstract: An RCD clamp circuit is usually used in flyback converters, in order to limit the voltage spikes caused by leakage transformer inductance. Oscillation ringing appears due to the clamp diode, which deteriorates the converter's power rate. This brief describes this ringing phenomenon and the use of an RC-RCD clamp circuit for damping the clamp diode's oscillation. This clamp circuit is capable for improving a flyback converter's power ratio.