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Circuit Parameters (circuit + parameter)
Selected AbstractsRobust optimum design of SAW filters by the penalty function methodELECTRICAL ENGINEERING IN JAPAN, Issue 3 2007Kiyoharu Tagawa Abstract In order to increase the reliability of surface acoustic wave (SAW) filters, a robust optimum design technique is presented. The frequency response characteristics of SAW filters are governed primarily by their geometrical structures, that is, the configurations of the interdigital transducers (IDTs) and reflectors fabricated on piezoelectric substrates. To choose desirable structures of SAW filters through computer simulation, conventional design techniques utilize the equivalent circuit model of the IDT. However, they have rarely considered the accuracy of the underlying model, which may be degraded by the dispersion of the circuit parameters. In this paper, considering the errors of these parameters, the robust optimum design of SAW filters is formulated as a constrained optimization problem. Then, a penalty function method combined with an improved variable neighborhood search is proposed and applied to the problem. Computational experiments conducted on a practical design problem of a resonator type SAW filter demonstrate the usefulness of the proposed method. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 158(3): 45,54, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20469 [source] Towards a circuit theory for metallic single-electron tunnelling devicesINTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 3 2007J. HoekstraArticle first published online: 20 APR 200 Abstract A circuit theory for metallic single-electron tunnelling (SET) junctions is presented. In detail circuits with a single SET junction in arbitrary environments are described. Based on the conservation of energy in the circuits,a fundamental circuit theorem,equivalent circuit elements are proposed and possible physical justifications are presented. The resulting model represents the tunnel event by an impulse current source, the junction by a charged capacitor, and the tunnelling condition as a discrete process based on local circuit parameters,and may include a tunnelling time. Simple examples illustrate Coulomb blockade, Coulomb oscillations, and continuous direct tunnelling. Copyright © 2007 John Wiley & Sons, Ltd. [source] Numerically distributed circuit parameters model on microstrip transmission line circuits and its application on CADINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 4 2003Xiaolong Zhong Abstract A new numerical model of microstrip transmission line circuits in terms of distributed circuit parameters is here illustrated. Based on full-wave electromagnetic results, the extraction methods of these distributed circuit parameters on different types of microstrip transmission line circuits are introduced. As a preparatory experiment, an improved CAD method using this model is tested on microstrip low-pass filter. Copyright © 2003 John Wiley & Sons, Ltd. [source] A new procedure for nonlinear statistical model extraction of GaAs FET-integrated circuitsINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 5 2003Francesco Centurelli Abstract A new statistical nonlinear model of GaAs FET MMICs which allows the representation of distance-dependent technological parameter variations by means of equivalent circuit parameters, and an automatic extraction procedure, are presented. The capability to reproduce statistical distribution has been successfully checked on S parameters at different distances in the 1,50 GHz frequency range. © 2003 Wiley Periodicals, Inc. Int J RF and Microwave CAE 13, 348,356, 2003. [source] S -parameter reciprocity relations, normalization, and thru-line-reflect error box completionINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 5 2002S. Vandenberghe Abstract The condition imposed by the Lorentz reciprocity theorem, which is a field property, on microwave circuit parameters is derived. The effect of power consistency and renormalization is discussed. A robust multireflect thru-line-reflect error box completion scheme is presented. The relative calibration is then converted into an absolute calibration using error box reciprocity. © 2002 Wiley Periodicals, Inc. Int J RF and Microwave CAE 12, 418,427, 2002. Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mmce10040 [source] A coupled FDTD-artificial neural network technique for large-signal analysis of microwave circuitsINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 1 2002S. Goasguen Abstract We propose a first-order global modeling approach of Monolithic Microwave Integrated Circuits (MMIC) by modeling the active device with a neural network based on a full hydrodynamic model. This neural network describes the nonlinearities of the equivalent circuit parameters of an MESFET implemented in an extended Finite Difference Time Domain mesh to predict large-signal behaviors of the circuits. We successfully represented the transistor characteristics with a one-hidden-layer neural network, whose inputs are the gate voltage Vgs and the drain voltage Vds. The trained neural network shows excellent accuracy and dramatically reduces the computational time in comparison with the hydrodynamic model. Small-signal simulation is performed and validated by comparison with HP-Libra. Then large-signal behaviors are obtained, which demonstrates the successful use of the artificial neural network. © 2002 John Wiley & Sons, Inc. Int J RF and Microwave CAE 12: 25,36, 2002. [source] Modeling and Simulation of a Transcutaneous Energy Transmission System Used in Artificial Organ ImplantsARTIFICIAL ORGANS, Issue 12 2009Wan Fang Abstract We present a mathematical model to simulate transcutaneous energy transmission systems. Treating such systems as resonant power electronic converters, we develop the equivalent circuit equations, for which the circuit variables are then expanded as Fourier series and a multi-frequency averaging method was applied. Keeping terms up to first-order, the analysis produces a dynamic and harmonic model describing these energy transmission systems. With appropriate values for the circuit parameters, numerical results are compared with those of the exact time domain model. This comparison verifies that our model can adequately represent to first-order such energy-transmission systems. [source] |