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Coupling Matrix (coupling + matrix)
Terms modified by Coupling Matrix Selected AbstractsCoupling matrix of a 10th -order dual-mode asymmetric canonical filterMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2003Juseop Lee Abstract This paper deals with a simple method to extract the coupling matrix of a 10th -order dual-mode asymmetric canonical filter. The coupling matrix of an asymmetric canonical filter is obtained by applying a plane rotation technique to the coupling matrix of a symmetric canonical filter. This paper gives a list of pivots and rotation angles to obtain the coupling matrix of an asymmetric canonical-structure filter. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 64,68, 2003 [source] Quantization of the ab initio nonadiabatic coupling matrix: The C2H molecule as a case studyINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 4-5 2001Michael Baer Abstract The observation that, for a given sub-Hilbert space, diabatic potentials, just like adiabatic potentials, have to be single-valued in configuration space led to the unavoidable conclusion that the relevant nonadiabatic coupling matrix (i.e., the matrix that contains the vectorial electronic nonadiabatic coupling terms) has to be quantized along any contour in configuration space. In the present article this statement is tested with respect to the three (excited) states of the C2H molecule, i.e., the 22A,, 32A,, and 42A, states. For this purpose ab initio electronic nonadiabatic coupling matrices were calculated along various contours surrounding the relevant conical intersections (one conical intersection between the 22A, and 32A, states and two conical intersections between the 32A, and 42A, states). Employing the line-integral technique it was shown that as long as the contour that surrounds the (2,3) conical intersection is close enough to the CI and avoids the two (3,4) conical intersections, the 2×2 nonadiabatic coupling matrices are quantized. However they fail to be quantized for contours that also surround one or two of the other conical intersections. In this case one is obliged to employ the three-state nonadiabatic coupling matrix. Doing that, it was shown that it is the 3×3 matrices that satisfy the quantization condition. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001 [source] Length-dependence of electron transfer coupling matrix in polyene wires: Ab initio molecular orbital theory study,INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 6 2009Govind Mallick Abstract The electron transfer (ET) properties of ,-electron conjugated quasi-one-dimensional molecular wires, consisting of polyene, [>CC<]n (n = 1,11), including ,-carotene, is investigated using ab initio molecular orbital theory within Koopmans theorem (KT) approach. The ET coupling matrix element, VDA, for 1,3- trans -butadiene molecule calculated with the KT approach shows excellent agreement with the corresponding results obtained with two-state model. The calculated values of VDA for the polyene oligomers exhibit exponential decrease in magnitude with increasing length of the wire. However, the decay curve exhibits three different regimes. The magnitude of the decay constant, ,, decreases with the increase in length of the wire. A highly delocalized ,-electron cloud in the polyene chain appears to facilitate retention of the electronic coupling at large separations between the donor and acceptor centers. Published 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009 [source] Quantization of the ab initio nonadiabatic coupling matrix: The C2H molecule as a case studyINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 4-5 2001Michael Baer Abstract The observation that, for a given sub-Hilbert space, diabatic potentials, just like adiabatic potentials, have to be single-valued in configuration space led to the unavoidable conclusion that the relevant nonadiabatic coupling matrix (i.e., the matrix that contains the vectorial electronic nonadiabatic coupling terms) has to be quantized along any contour in configuration space. In the present article this statement is tested with respect to the three (excited) states of the C2H molecule, i.e., the 22A,, 32A,, and 42A, states. For this purpose ab initio electronic nonadiabatic coupling matrices were calculated along various contours surrounding the relevant conical intersections (one conical intersection between the 22A, and 32A, states and two conical intersections between the 32A, and 42A, states). Employing the line-integral technique it was shown that as long as the contour that surrounds the (2,3) conical intersection is close enough to the CI and avoids the two (3,4) conical intersections, the 2×2 nonadiabatic coupling matrices are quantized. However they fail to be quantized for contours that also surround one or two of the other conical intersections. In this case one is obliged to employ the three-state nonadiabatic coupling matrix. Doing that, it was shown that it is the 3×3 matrices that satisfy the quantization condition. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001 [source] A new equivalent circuit for inverters and its application for the determination of coupling matrix elements of narrow RF bandpass filtersINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 1 2010M. 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] Exhaustive approach to the coupling matrix synthesis problem and application to the design of high degree asymmetric filtersINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 1 2007Richard J. Cameron Abstract In this paper a new approach to the synthesis of coupling matrices for microwave filters is presented. The new approach represents an advance on existing direct and optimization methods for coupling matrix synthesis, in that it will exhaustively discover all possible coupling matrix solutions for a network if more than one exists. This enables a selection to be made of the set of coupling values, resonator frequency offsets, parasitic coupling tolerance, etc. that will be best suited to the technology it is intended to realize the microwave filter with. To demonstrate the use of the method, the case of the recently introduced "extended box" coupling matrix configuration is taken. The extended box is a new class of filter configuration adapted to the synthesis of asymmetric filtering characteristics of any degree. For this configuration the number of solutions to the coupling matrix synthesis problem appears to be high and offers therefore some flexibility that can be used during the design phase. We illustrate this by carrying out the synthesis process of two asymmetric filters of 8th and 10th degree. In the first example a ranking criterion is defined in anticipation of a dual mode realization and allows the selection of a "best" coupling matrix out of 16 possible ones. For the 10th degree filter a new technique of approximate synthesis is presented, yielding some simplifications of the practical realization of the filter as well as of its computer aided tuning phase. © 2006 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2007. [source] Dynamics and Coupling Actuation of Elastic Underactuated ManipulatorsJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 3 2003Tie Shi Zhao This paper investigates the constraint and coupling characteristics of underactuated manipulators by proposing an elastic model of the manipulator and examining the second order constraint equation. A dynamic model and a coupling constraint equation are developed from a Jacobian matrix and the Newton-Euler formulation. The inertia matrix and the Christoffel tensor are analyzed and decomposed into the part concerning actuated joints and the part concerning passive joints. This decomposition is further extended to the dynamic coupling equation and generates an actuation coupling matrix and a dynamic coupling tensor. Two new dynamic coupling indices are hence identified. One is related to an actuation input and the other is related to centrifugal and Coriolis forces. The former reveals the dynamic coupling between the input and the acceleration of passive joints and gives the actuation effect on the passive joints. The latter reveals the dynamic coupling between the centrifugal and Coriolis forces and the acceleration of passive joints and provides the centrifugal and Coriolis effect on the acceleration of passive joints. The study reveals the coupling characteristics of an underactuated manipulator. This is then demonstrated in a three-link manipulator and extended to a serial manipulator with passive prismatic joint. © 2003 Wiley Periodicals, Inc. [source] Coupling matrix of a 10th -order dual-mode asymmetric canonical filterMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2003Juseop Lee Abstract This paper deals with a simple method to extract the coupling matrix of a 10th -order dual-mode asymmetric canonical filter. The coupling matrix of an asymmetric canonical filter is obtained by applying a plane rotation technique to the coupling matrix of a symmetric canonical filter. This paper gives a list of pivots and rotation angles to obtain the coupling matrix of an asymmetric canonical-structure filter. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 64,68, 2003 [source] | ||||||||||