bluuebunny/crossref_metadata_2025_split huggingface dataset:
An index of phase distortion
Authors: Clarke B. R. 
Published: July 2007

AbstractMeasures exclusively reflecting phase distortion are examined and a new phase distortion ‘index’ is proposed. This index, based on the mean‐squared degradation in the impulse response of a filter, is shown to be equivalent to a phase distortion ‘spot‐measure’ using the variation in the peak value of the impulse response, due to phase distortion, of the cascade combination of two identical filters. This equivalence allows the spot‐measure to be employed for rapid phase distortion evaluation without loss of accuracy in reflecting phase distortion.
A unified construction of adjoint systems and networks
Authors: Narayanan H. 
Published: July 2007

AbstractIn this paper we introduce a technique for dealing with implicitly defined complementary orthogonal spaces. Using this technique we give a unified construction of various types of adjoint systems for dynamical systems defined through flow diagrams or graphs and also obtain the state and output equations of the adjoint systems in terms of the corresponding equations for the original system. Among other things we show how to construct the Kalman dual of a linear electrical network.
Switched capacitor filters with a row dominant nodal admittance matrix
Authors: Hasler Martin , Saghafi Morad 
Published: July 2007

AbstractStray capacitance insensitive switched capacitor filters are studied, whose nodal admittance matrix is row‐dominant for arbitrary capacitor values. Such filters have low passband sensitivities, because their transfer function is intrinsically bounded by 1, as is the case for LC‐filters. Furthermore, row‐dominant filters have the additional advantage that internal voltages are bounded by one, and reach this bound at each attenuation zero, which ensures optimal dynamic range. However, we show that the attenuation zeros of row‐dominant filters are located at the frequencies z2 with (z2)m = 1, where m is smaller than or equal to the number of operational amplifiers. Therefore, such filters are not suitable for conventional filter applications. Two examples of such filters are given.
Efficient solution of the variational equation for piecewise‐linear differential equations
Authors: Parker Thomas S. , Chua Leon O. 
Published: July 2007

AbstractA closed‐form solution of the variational equation associated with a piecewise‐linear differential equation is derived. This closed‐form solution is used to develop an efficient method for calculating the solution of the variational equation. The method relies on the matrix exponential and requires no integration beyond the calculation of the trajectory along which the variational equation is being solved. Numerical results for the three‐dimensional case show an increase in efficiency of one to two orders of magnitude over the traditional method.
Devil's staircase route to chaos in a non‐linear circuit
Authors: Chua L. O. , Yao Y. , Yang Q. 
Published: July 2007

AbstractA driven second‐order negative‐resistance oscillator circuit has been observed experimentally to exhibit infinitely many distinct chaotic states in addition to infinitely many subharmonic responses of all orders. Each chaotic state is found to be born out of a devil's staircase whose steps are spaced in accordance with a definite period‐adding law.Each devil's staircase emerges at some level of frequency‐tuning resolution, where each level is embedded within an outer level, ad infinitum. The global bifurcation structure is self‐similar in the sense that upon rescaling, the devil's staircases appear to be clones of each other.
On the optimum design of symmetric two‐dimensional IIR digital filters with coefficients of finite word length
Authors: Papamarkos N. , Mertzios B. , Vachtsevanos G. 
Published: July 2007

AbstractA method is described for the design of octagonally symmetric, non‐symmetric half plane, two‐dimensional IIR digital filters with integer coefficients. The design problem is formulated as an integer non‐linear problem and the solution is achieved via an integer non‐linear optimization algorithm. An example illustrates the features of the proposed approach.
A method of analogue‐digital multiple fault diagnosis
Authors: Reisig David , Decarlo Raymond 
Published: July 2007

AbstractThis paper develops an algorithm for multiple fault diagnosis of analogue‐digital circuits. By sequentially partitioning the devices into those ‘assumed good’ and those ‘under test’, it is possible to develop a set of fault diagnosis equations which account for the special nature of digital components. A modified Newton‐Raphson solution is then described which incorporates a digital state hypothesis testing scheme in the solution of the fault diagnosis equations for each partition. After solving for the input‐output characteristics of the devices under test, a Boolean decision algorithm is used to analyse the test results of each partition and thus sequentially arrive at the set of faulty elements. A generic condition for diagnosability in terms of the circuit topology is given. Two examples are included to illustrate the technique.
Transfer maps and return maps for piecewise‐linear three‐region dynamical systems
Authors: Kahlert Claus , Chua Leon O. 
Published: July 2007

AbstractTechniques formerly developed in the theory of Poincaré half‐maps are modified and applied to the three‐region piecewise‐linear continuous dynamical system associated with Chua's circuit. Both transfer and return maps, induced by the trajectories inside the intermediate region in state space, are formulated as implicit equations. the boundaries of the domains of these maps are determined explicitly, using the method for calculating the initial points of touching trajectories subject to appropriate switching dynamics. A charting of the canonical parameter space of the dynamics that acts on the intermediate region is indicated. Among other things, this chart reveals the existence of new types of chaotic attractors different from the double scroll and Rössler attractors previously discovered from Chua's circuit.
On filter pairs with butterworth characteristics
Authors: Belevitch Vitold 
Published: July 2007

AbstractThe paper deals with the design of 3‐ports consisting of the parallel connection, at port 1, of a lowpass ladder of degree n having all its attenuation poles at infinity, with a highpass ladder of degree m having all its attenuation poles at DC, the purpose of the design being to achieve a Butterworth (maximally flat) behaviour, simultaneously in the lowpass direction (1‐2) at DC and in the highpass direction (1‐3) at infinity. Norton1 has solved the case m = n for constant impedance filter pairs. the much more difficult case where one of the above restrictions is not met is discussed in general terms and some new results are obtained. Although the problem is far from being completely solved, useful explicit design relations are established for a few filter pairs of low degrees.
Ideal rectifier n‐ports are solvable
Authors: Belevitch Vitold 
Published: July 2007

AbstractIt is proved that an n‐port composed of ideal transformers, gyrators and ideal rectifiers has a unique solution for the port variables when it is excited by generators in series with strictly positive resistances. the multiplicity of solutions for the internal variables is discussed. Connections are established with the theory of linear inequalities and with the coloured branch theorem of graph theory.
Topological transformations of electrical networks
Authors: Narayanan H. 
Published: July 2007

AbstractThis paper deals with effects of modifications of network structure that may be studied without reference to the type of devices present in the network. We introduce and make systematic use of the notion of a generalized minor of a vector space. This operation generalizes the usual short and open circuit operations for a graph. Using the generalized minor operation we show how to make the equations of a given network appear to be the ‘bordered version’ of the equations of some other specified network. We also consider the decomposition of a network into several ‘multiports’ and a ‘port connection diagram’, and study the properties of a minimal decomposition (with port connection diagram having a minimum number of edges). In each case we present efficient algorithms wherever appropriate. Although the paper makes use of ideas from elementary matroid theory it is entirely self‐contained and requires no more than the knowledge of elementary linear algebra from the reader.
Elements of four‐port matrix theory as required for sc network analysis
Authors: Moschytz G. S. 
Published: July 2007

AbstractFour‐port matrix theory is the foundation for various useful methods of analysing switched‐capacitor networks. Thus, for example, signal‐flow graph techniques, the link‐two‐port concept, and nodal computer analysis methods are based on either the four‐port transmission or admittance matrix. In the derivation of these analysis techniques transmission, reverse‐transmission, and transfer matrices are often used, but the relationship between them has not yet been clearly formulated for four‐port networks. In this paper an attempt at formulation and clarification is made. Furthermore, it is shown that, once the considerable simplifications due to the presence of opamps are taken into account, a simple and elegant method of hand analysis for basic SC circuits using a combination of transmission and transfer matrix parameters results.
Weakly non‐linear oscillator circuits and averaging: A general approach
Authors: Bernstein G. M. , Chua L. O. 
Published: July 2007

AbstractThe method of averaging has been used for years to prove the existence of oscillations in non‐linear circuits. In the past the application of averaging has tended to be ad hoc rather than systematic. In addition the validity of the method was not well established. the purpose of this paper is to rigorize and systematize the analysis of weakly non‐linear oscillator circuits via the method of averaging. In particular this paper will put on a rigorous foundation the work of Kuramitsu et al.1‐3 on the ‘averaged potential’ and the work of T. Endo and others on the oscillatory modes of coupled oscillator circuits. Furthermore we give a novel way of simplifying the calculation of averages when we have a potential function representation.
The topological foundations of electrical networks — complete models
Authors: Acciani G. , Cafaro G. , Dichirico C. , Vacca F. 
Published: July 2007

AbstractThe aim of this paper is to identify the topological entities underlying the construction of a complete (not reduced) network model. Consider an active network as a pair of physically different structures, i.e. a ‘dead network’ and an ‘excitation’. First, we define the general structure of the excitation which can be applied to a dead network; then the graphs Ga and G of the active and dead networks, respectively, are introduced. It is shown that, if a complete network model is to be constructed, the topological relations among the voltages and those among the currents of the network elements must be written choosing maximal independent sets of loops and cut‐sets of Ga. It is successively pointed out that the graph G can be obtained from Ga by means of a reduction operation, and the topological entities of G corresponding to the loops and to the cut‐sets of Ga are singled out. It has been found that a complete model of an electric network implies the use of four topological entities defined on the set of G‐edges, i.e. the closed path, the open path, the cut‐set and the pseudo‐cut, together with two topological entities defined on a maximal set of independent vertex couples of G, i.e. the ‘junction pair’ extreme of an open path and the ‘family of independent node couples’ split by a cut‐set.Furthermore the different reference frames and the relative topological matrix transformations which allow a complete model of the network to be built up are singled out and discussed.
Bit‐serial vlsi implementation for an optimized transmultiplexer design
Authors: Catthoor Francky , de Man Hugo , Vandewalle Joos 
Published: July 2007

AbstractThe silicon implementation of a transmultiplexer system, from the high level description up to the floor‐plan, is presented. the described realization allows to integrate an entire 12‐channel TDM‐FDM transmultiplexer system on a silicon area of less than 80 mm2in a 5 μm single‐metal race‐free dynamic CMOS technology, making use of an available bit‐serial standard‐cell library. At the architectural level, a hardware‐sharing transformation combined with a number of optimizations for the coefficient quantization and the choice of the data word‐length, have allowed for a global area‐reduction of almost 50 per cent.First a mainly manual approach has been investigated, where the hierarchical decomposition has been exploited to perform global and local optimizations in terms of the hardware. Later on, based on this experience, it has been employed as a major test vehicle for the CAD tool‐box of the bit‐serial silicon compiler1,2which has been developed during the pilot phase of an ESPRIT research project at our laboratory. Extensive use has been made of programs for filter synthesis, optimization, bit‐serial mapping, delay management and standard‐cell placement and routing. the results obtained with both design strategies are compared.This research has given a concrete example of how systems, filter, network, circuit and CAD experience can be effectively combined into a VLSI design.
Topological conditions for the unique solvability of linear time‐invariant and time‐varying networks
Authors: Poletti Mario , Terreni Pierangelo 
Published: July 2007

AbstractThe problem of knowing whether the non‐unique solvability depends on the particular values of the components or on their topological interconnections is studied for linear networks with arbitrary, time‐invariant as well as time‐varying n‐ports.Within every network, the topological notions of its sockets and of their independence are introduced. Networks with independent sockets are shown‐at least when there are no relations among the non‐zero coefficients, nor repetitions of the same coefficient are allowed, i.e. under suitable generality assumptions‐to be uniquely solvable. Networks with dependent sockets are shown to be never uniquely solvable.Polynomially bounded algorithms, requiring only integer arithmetic, to test independence are available. When independence fails, a topological configuration of components which shows fewer topologically independent variables than equations, is proved to exist.
A substitution algorithm for solving nonlinear circuits with multi‐frequency components
Authors: Ushida A. , Chua L. O. , Sugawara T. 
Published: July 2007

AbstractIn this paper, we present an efficient algorithm for calculating the steady‐state response of nonlinear circuits such as forced circuits driven by multi‐frequency‐component signals, forced oscillators, and coupled oscillators. We call the technique a substitution method because the variation at each step is calculated by solving an associated time‐invariant sensitivity circuit at each frequency component of the residual error, whose circuit is derived from a relaxation method. the algorithm is very simple and efficient, and it can be applied to a wide variety of nonlinear circuits.
A systematic approach to the design of stray‐insensitive sc circuits from active‐RL or RLC prototypes
Authors: Rathore T. S. , Bhattacharyya B. B. 
Published: July 2007

AbstractA systematic approach to the design of stray‐insensitive switched‐capacitor (SC) circuits from active‐RC or RLC prototypes employing a parasitic insensitive SC differential voltage‐controlled current‐source as a basic building block is attempted. Procedures for transforming active‐RC and RLC circuits into stray‐insensitive SC circuits are formulated and illustrated with typical examples. Restrictions on the pole‐frequency and pole‐Q of the SC biquad are derived so that it closely emulates the frequency response of the original active‐RC biquad. the SC biquad and the ladder filter derived by the proposed procedures were simulated with discrete components and tested in the laboratory. Test results agree closely with the theoretical predictions.
The ranges of transfer and return maps in three‐region piecewise‐linear dynamical systems
Authors: Kahlert Claus 
Published: July 2007

AbstractThe ranges of the transfer and the return maps that are induced by the flow of a piecewise‐linear continuous dynamical system describing Chua's circuit are investigated analytically. the two sets turn out to be intertwined for all values of the parameters. For high enough frequencies of the saddle‐focus, located at the origin of state space, the first set forms ‘inclusions’ inside the second one. A charting of parameter space describing the creation and annihilation of the above inclusions quantitatively is indicated.
Multimode oscillator analysis via integral manifolds part I: Non‐resonant case
Authors: Chua Leon O. , Endo Tetsuro 
Published: July 2007

AbstractThis article represents Part I of a two‐part paper which provides a rigorous mathematical foundation of the modeanalysis method for analysing the periodic and quasi‐periodic oscillations observed in various types of coupled oscillators. Although the results predicted by this method had been confirmed by experiments to some extent, the crucial assumptions used to derive the averaged equations are based on engineering intuition. Moreover, while it is intuitively reasonable to associate an equilibrium solution of the averaged equations whose eigenvalues have negative real parts with that of a stable periodic or quasi‐periodic solution of the original equation, the relationship between the solution of the averaged equations and that of the original equations as t tends to infinity, is not clear in a mathematical sense.This paper resolves the theoretical ambiguities of the mode analysis method by using the theory of integral manifolds. In particular, we recalculate the averaged equations in a rigorous way, and show that they coincide with those obtained before. Therefore, the theory of integral manifolds guarantees the existence of an integral manifold in the original system which corresponds to a steady‐state periodic or quasi‐periodic solution, provided the equilibrium point of the averaged equation has no eigenvalues with a zero real part (i.e. hyberbolic). This rigorous analysis proved that all our previous results obtained from the mode analysis method, i.e. averaged equations and stability analysis were correct.
Multimode oscillator analysis via integral manifolds part II: Resonant case
Authors: Chua Leon O. , Endo Tetsuro 
Published: July 2007

AbstractThis article represents Part II of a two‐part paper which provides a rigorous mathematical foundation of the modeanalysis method for analysing the periodic and quasi‐periodic oscillation observed in various types of coupled oscillators. Although the results predicted by this method had been confirmed by experiments to some extent, the crucial assumptions used to derive the averaged equations are based on engineering intuition. Moreover, while it is intuitively reasonable to associate an equilibrium solution of the averaged equations whose eigenvalues have negative real parts with that of a stable periodic or quasi‐periodic solution of the original equation, the relationship between the solution of the averaged equations and that of the original equations as t tends to infinity, is not clear in a mathematical sense.This paper resolves the theoretical ambiguities of the mode analysis method by using the theory of integral manifolds. In particular, we recalculate the averaged equations in a rigorous way, and show that they coincide with those obtained before. Thereore, the theory of integral manifolds guarantees the existence of an integral manifold in the original system which corresponds to a steady‐state periodic or quasi‐periodic solution, provided the equilibrium point of the averaged equation has no eigenvalues with a zero real part (i.e. hyperbolic. This rigorous analysis proved that all our previous results obtained from the mode analysis method, i.e. averaged equations and the analysis were correct.
Layout including parasitics for printed circuit boards
Authors: Wawryn Krzysztof 
Published: July 2007

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 presented.
High‐speed non‐linear circuit models for p‐n junction diodes
Authors: Chua Leon O. , Chang Chwen‐Cher 
Published: July 2007

AbstractCircuit models for both long‐base and short‐base p‐n junction 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‐order dynamic elements and includes the conventional diffusion model as a special case. the new dynamic model can be used for simulating arbitrary p‐n junction 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 the frequency‐dependent small‐signal characteristics of p‐n junction 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 non‐linear device modelling.