摘要:

AbstractAn automatic layout system is developed for optimal simultaneous placement of elements and equipotential nodes and routing interconnection paths that can be applied to multilayer analogue printed circuit boards (PCBs) including parasitic couplings. the objective is to minimize the influence of parasitic capacitance and inductance couplings of printed paths on performance of analogue circuits as an electrical criterion. A force model has been used to determine optimal placement where the sensitivities of network function on parasitic capacitances and inductances are the sets of weighted coefficients between forces of attractions and repulsions. the routing algorithm is a combination of topographic simulation method with minimum length connection path. the topography of predicted parasitic couplings is formed before each connection path is routed where the sensitivities of the network function on parasitic capacitances and inductances create the heights of tops. Placement and routing algorithms have been developed, programmed and compared with conventional force algorithm and the Lee algorithm. Practical results of frequency characteristics of printed circuit boards of a wide‐band HF amplifier have been obtained and presente

ISSN:0098-9886    

DOI:10.1002/cta.4490160202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractFormulations of systems of Lagrange and Routh equations for arbitrary non‐linear electrical circuits are given. the use of Routh equations for this purpose is new. It is proved that these formulations are equivalent to the complete system of Kirchhoff equations (instead of only a part of it as in prior works). the vector of generalized coordinates for the system of Lagrange equations consists of four subvectors (loop charges for fundamental loops, cut‐set fluxes for fundamental cut‐sets, branch fluxes for voltage and flux controlled elements and branch charges for current and charge controlled elements).For the defined set of Lagrange formulations, the uniqueness of a parametric representation is proved. the structure of the Lagrange (Hamilton, Routh) formulation set is then studied and it is proved that this set is an Abelian group. A duality of Lagrange triples for electrically and topologically dual circuits is established and it is proved that this relation between the sets of Lagrange triples is an isomorphism. It is also shown that the Brayton‐Moser equations and the anti‐Lagrangian equations similar to those of M. Milić and L. Novak represent partial cases of the form

ISSN:0098-9886    

DOI:10.1002/cta.4490160203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractIn the past network models have been used frequently to simulate the Laplace's, wave and diffusion equations. In this paper the application of the network model is further extended to include the diffusion‐convection equation. the time‐dependent diffusion‐convection equation is first modelled by anRCelectric network from which a set of ODEs is derived. Numerical experiments are then performed to compare the network model and the method of lines in solving the one‐dimensional linear diffusion‐convection equation and the Burgers' equation where highly non‐linear network components are required. It is shown that, for the former problem, the network method has improved accuracy for low Peclet numbers. At high Peclet numbers the behaviour of the network method resembles that of the method of lines (MOL) with upstream‐differencing. Spurious oscillations are absent. Computing time required to solve the network is slightly less than that for the MOL. For the Burgers' equation, the network method shows a substantial improvement over the MOL in terms of accuracy with no oscillations but requires longer c

ISSN:0098-9886    

DOI:10.1002/cta.4490160204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractCircuit models for bothlong‐baseandshort‐base p‐njunction diodes which are valid for non‐linear high‐speed and high‐frequency operations are presented. the diode model consists of a parallel connection of higher‐orderdynamicelements and includes the conventional diffusion model as a special case. the new dynamic model can be used for simulating arbitraryp‐njunction diode circuits under all operating conditions. In particular, it is capable of simulating realistically the diode's reverse transient behaviour and providing an increasingly accurate approximation to the diffusion equation as the order of the model gets higher. the model is also shown to be capable of reproducing thefrequency‐dependentsmall‐signal characteristics ofp‐njunction diodes.The model is based mainly upon the device's physical operating principles. Perhaps the most significant implication of the model is the fact that it illustrates the important roles played by higher‐order and dynamic elements in highspeed and high‐frequency no

ISSN:0098-9886    

DOI:10.1002/cta.4490160205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractAn explicit criterion is given which guarantees that the solutions of a system of two first‐order differential equations have a unique asymptotic behaviour as t'→ + ∞. the equations are allowed to be time‐dependent, with isolate discontinuities (switching), and non‐linear. In particular, continuously differentiable and piecewise linear systems, as far as the dependence on the state variables is concerned, are considered. the particular case of a linear system switched back and forth between two 2 × 2 matrices is treated in detail, with an outline of an algorithm to decide on the converence to zero of the solutions.The case of switching betweenNmatrices is a straightforward generalization that is, however, not covered in this paper. It is shown that the problem of unique asymptotic behaviour of piecewise linear systems can always be treated by considering such switched linear systems. Furthermore, an example shows that even some continuously differentiable systems may be reduced to this case. Finally, the connection with the work of Brayton and Tong on the stability of differential equations, also using sets of matrices

ISSN:0098-9886    

DOI:10.1002/cta.4490160206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

ISSN:0098-9886    

DOI:10.1002/cta.4490160207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

ISSN:0098-9886    

DOI:10.1002/cta.4490160201

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY