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Circuit Representations (circuit + representation)

Distribution by Scientific Domains
Engineering100%

Selected Abstracts

Temperature-frequency characteristics simulation of piezoelectric resonators and their equivalent circuits based on three-dimensional finite element modelling

INTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 6 2003
N. Wakatsuki
Abstract The electromechanical resonators made of piezoelectric crystals such as a quartz crystal are widely used for electronic devices. Their frequency,temperature characteristics are of primary importance for their applications to the frequency control devices. The present paper demonstrates numerical simulation for several types of resonators using 3-D Finite Element Modelling. The results are compared with the theoretical values whenever they are available. As they are electronic devices, the equivalent circuit representation is often favourable for describing the admittance at the electrical terminals which enables the circuit analysis including the effect of the temperature change by using commercially available circuit simulators. Copyright © 2003 John Wiley & Sons, Ltd. [source]

Equivalent circuit representation for integral formulations of electromagnetic problems

INTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 1 2002
H. Baudrand
The purpose of this study is to investigate the resources offered by electromagnetic equivalent circuits as a tool for the systematic derivation of integral equations and also, to propose consistent models for active sources. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Generation, modeling, and analysis of CCII-based gyrators using the generalized symbolic framework for linear active circuits

INTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 3 2008
Ramy A. Saad
Abstract In this paper, CCII-based gyrators are synthesized, modeled, and analyzed using the generalized symbolic framework for linear active circuits. The systematic synthesis method using admittance matrix expansion, included in the framework, is applied to generate optimized nullor,mirror descriptions for the gyrator. The resulting CCII-based circuit representations for the gyrators, obtained from mapping nullor,mirror pairs in the ideal realizations with equivalent second-generation current conveyors (CCIIs), can be classified into two topologies according to the type of the CCII terminals handling the gyrator input and output signals. In topology I, the gyrator input and output terminals are CCIIs Y,Z -terminals, whereas in topology II, the gyrator input and output terminals are CCIIs X -terminals. The parasitic components within the synthesized circuits, associated with the actual CCIIs, are modeled and included in their expanded admittance matrices. Exact non-ideal analysis for two circuits belonging to the two topologies, involving the reduction of their expanded admittance matrices to port admittance matrices, is then carried out to investigate the practical functional performance for these circuits at their ports. The non-ideal performance analysis based on the CCII actual parasitic elements indicates that, from a practical perspective, the CCII-based gyrator circuits belonging to topology I are more efficient and suitable for the gyrator applications than those belonging to topology II in terms of bandwidth and operation at high frequencies. SPICE simulations are included to demonstrate the analytical results for the comparison between the practical performances of the two circuit topologies. Copyright © 2007 John Wiley & Sons, Ltd. [source]

A new equivalent circuit for inverters and its application for the determination of coupling matrix elements of narrow RF bandpass filters

INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 1 2010
M. K. Haldar
Abstract A new equivalent circuit for inverters is presented. Using this circuit, expression for the elements of the coupling matrix of narrow RF band pass filters is derived. The derivation is based on frequency independent coupling assumed in the synthesis of narrow RF band pass filters. Our expression is different from an earlier expression obtained using lumped circuit representations of different types of coupling and their analysis. It is shown that the earlier expression can be derived from our analysis if the coupling is assumed frequency-variant. Unlike earlier work, our derivation shows how the sign of the coupling coefficient can be obtained. © 2009 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010. [source]

New and efficient modeling for telecommunication devices

INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 3 2002
T. P. Vuong
Abstract With the collaboration of the CNES, a new modeling method for telecommunication devices, presented in this article, has been implemented on any computer. This method combines the variational method, based on electric equivalent circuit representations, and the boundary element method. Results are successfully compared to measurements and those from the previous publications. © 2002 Wiley Periodicals, Inc. Int J RF and Microwave CAE 12: 247,258, 2002. [source]