bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lossless 2‐ports between non‐reactive terminations
Authors: Hasler Martin 
Published: July 2007

AbstractLossless reciprocal 2‐ports between terminations with even impedance functions are considered. They are the unifying concept for the synthesis of FDNR and leapfrog RC‐active filters in their most general form. The scattering matrix of lossless reciprocal 2‐ports with respect to such terminations is defined, its canonic form deduced and the transfer of active power discussed. This scattering matrix is related to the usual scattering matrix of the same 2‐port but with respect to unit resistance terminations. In such a way the precise structure of the 2‐port as an LC ladder can be deduced from properties of the original transfer function and the termination impedances and the LC synthesis can be performed by conventional methods and programs. An exhaustive enumeration of the different cases that may arise is given. It can give a general outlook on the different RC‐active filters that may be obtained.
A practical closed form solution for systems with variable eigenvalues via bilinear system theory
Authors: Brandenbusch Wolfgang , Stehle Werner 
Published: July 2007

AbstractThis paper treats systems in state variable formulation with non‐constant, parameter controlled system matrices. The synthesis of a system with controlled eigenvalues (ECS) is given. The synthesized system is a commutative bilinear system. Its solution has a closed form and is based on the solution of just one time invariant system although as many arbitrary time functions are involved as the system has independent states. The ECS is homologous to any system with a system matrix being an arbitrary, possibly time‐dependent function of a single constant system matrix.All results are deduced for multiple eigenvalues of the system matrix including single eigenvalues as a special case. They are fully analogous to the solution of time invariant systems by means of the Laplace transformation.
Lossless chain scattering matrices and optimum linear prediction: The vector case
Authors: Dewilde Patrick , Dym Harry 
Published: July 2007

AbstractIn this paper we give a systematic treatment of the exact and approximate realization of a positive real matrix‐valued function on the open unit disc by means of a lossless circuit connected to a passive load. We discuss the mathematical properties of the chain scattering matrix which describes the lossless circuit and rederive a form of the classical Darlington synthesis theorem generalized to roomy matrix‐valued transmission functions. We then develop a matrix version of an algorithm due to Schur for the construction of approximate realizations which produces (minimal degree) Nevanlinna–Pick approximants to the original positive real matrix. We further identify the normalized inverse of one of the outer factors of the approximant to the positive real matrix as the orthogonal projection of the identity onto a suitably defined subspace, give its interpretation as a reproducing kernel, and establish strong convergence under mild conditions on the growth of the order of the approximation. Finally we interpret and apply the mathematical theory developed in the body of the paper to the theory of prediction for vector‐valued second order stationary stochastic sequences and briefly discuss connections with the theory of maximum entropy extensions and of inverse scattering.
On the role of the Nevanlinna–Pick problem in circuit and system theory
Authors: Delsarte Ph. , Genin Y. , Kamp Y. 
Published: July 2007

AbstractThe paper is concerned with applications of the standard Nevanlinna–Pick problem in various technical domains, namely the following: interpolation by reflectance functions, polynomial stability checking, cascade synthesis of passive one‐ports, and model reduction with a Hankel norm criterion. Some fundamental results on the Nevanlinna–Pick problem are shown to be of a definite interest in each of these subjects.
The state‐space realization of an n‐dimensional transfer function
Authors: Galkowski Krzysztof 
Published: July 2007

AbstractIn this paper the non‐minimal real state‐space realization for n‐dimensional transfer functions with polylinear numerators and denominators is stated and proved. It is also shown that the every existing realization of an n‐dimensional transfer function can be achieved from the companion matrix of some (n + 1)‐variable polynomial linear with respect to one of its variables.
Unification of active filters with passive sections having a single internal node
Authors: Bowron P. , Al‐Kabbani A. S. S. 
Published: July 2007

AbstractA linear graph representation of the passive section in a multiple‐amplifier active filter is used to characterize the general transfer‐function matrix. This enables unification of a wide range of single and double‐amplifier circuits. In the case of a single internal node, some familiar active‐RC and new active‐R configurations emerge. As examples, a second‐order lowpass ‘partial active‐R’ structure of low sensitivity is developed as well as a two‐amplifier active‐R filter which exploits the internal node to provide higher selectivity and increased tuning facility.
Theory of an iterative, two mode transmission network
Authors: Skipping C. R. , Moore B. N. , Oakes M. E. 
Published: July 2007

AbstractA general investigation of the nature of an iterative, LC lattice structure, shown to function as a transmission channel capable of carrying two distinct wave modes, is carried out. Both a uniform system and an inhomogeneous case where the capacitor values vary slowly down the lattice structure are considered. Emphasis is placed on a formal and numerical investigation of basic wave properties and their significance with regard to signal transmission, crosstalk suppression, plus the particularly interesting phenomenon of one mode converting to the other which is found to occur in the inhomogeneous case. Potential uses of the lattice such as simulated wave studies, among others, are suggested. Relations for termination impedances are derived, and special cases involving different combinations of excitation and termination conditions are considered.
On the solvability and computation of D.C. transistor networks
Authors: Tadeusiewicz Michal 
Published: July 2007

AbstractA study of non‐linear d.c. networks containing transistors, diodes, linear resistors, independent voltage and current sources and linear controlled voltage and current sources, described by Tf(x) + Gx = b is presented. A few theorems concerning both the solvability and numerical computation of d.c. transistor networks are proved. The conditions sufficient for the existence of at least one solution and of a unique solution are defined. A method for numerical computation of the networks without the need to determine inverse matrices is presented and the convergence of the iterative technique is analysed. Suggestions are formulated regarding applicability of the method for computation of an approximate solution (close to the exact solution) which may subsequently be quickly corrected using the Newton‐Raphson method.
Filter realization using a generalized lagrange polynomial representation
Authors: Liu Frank C. , Marshall Thomas G. 
Published: July 2007

AbstractA polynomial representation using a set of generalized Lagrange polynomials for a basis is considered as an alternative to the natural representation. This new representation, which is employed in a previously described APL filter design package,8 is considered in detail, here, with regard to its algebraic and numerical properties for solving the realization problem of electrical filter synthesis. The necessary polynomial operations for filter realization are described in this representation. Then vector space algorithms are presented for these operations. The accuracy obtained from this representation is discussed. Advantages in both accuracy and simplicity of the new algorithms are noted.
A routing system based on a single‐row router and its wirability
Authors: Asahara Shigeo , Odani Maysayasu , Ogura Yasunori , Shirakawa Isao , Ozaki Hiroshi 
Published: July 2007

AbstractA new routing system is described, which can be applied to printed wiring boards of different wiring densities such that the number of wiring tracks permitted between two consecutive pins of an ordinary dual in line package ranges from one to four. This system is distinctive in that a single‐row router is combined with a line‐search router in such a way that the search for possible wire segments at the stage of the line search router is implemented channel by channel, with all interconnections within each channel completed later by the single‐row router.The program operates on an ACOS 77/900 computer, and has been applied to numbers of boards. Some of the implementation results are also shown to reveal how much the described system may attain its potentialities in the practice of layout of high density printed wiring boards.
A new approach to routing of two‐layer printed circuit board
Authors: Marek‐Sadowska M. , Kuh E. S. 
Published: July 2007

AbstractThis paper presents a new method for routing two‐layer printed circuit boards with fixed geometry, i.e. alternate columns of pins and vias. Circuit components are mounted on top of the board, and conductor wires are to be laid on the board such that circuit connections can be properly made. The proposed approach gives 100 per cent routability. The method consists of three steps, namely: partitioning of multi‐pin nets into 2‐pin subnets, via assignment, and routing on the two layers. In comparison with the traditional unidirectional routing, the method offers more flexibility and it requires usually about half as many vias. A computer program based on the presented algorithms was written. Its implementation is presented along with testing examples.
Optimum lowpass and bandpass filter approximation
Authors: Beccari Claudio , Molinaro Maurizio 
Published: July 2007

AbstractThe attenuation characteristics of lowpass and bandpass rational filters are approximated by optimizing a weighted error criterion. The analytical approach yields the solution in terms of kernel polynomials, and if the weight function has a particular form, the solution may be given explicitly in terms of the Szegö–Bernstein polynomials; with other weight functions it is necessary to resort to numerical procedures. The solution exhibits a passband behaviour that depends on the chosen weight function; when the Szegö–Bernstein polynomials are used both lowpass and bandpass filters may exhibit equiripple passband attenuation.
Energy‐related concepts for non‐linear time‐varying n‐ports: Passivity and losslessness
Authors: Gannett J. W. , Chua L. O. 
Published: July 2007

AbstractDefinitions of passivity and losslessness are presented that apply to n‐port networks which are not necessarily linear, time‐invariant, or lumped; in fact, these definitions apply to any n‐port that has an abstract dynamical system representation. For lumped, non‐linear n‐port networks that can be mathematically represented by a finite‐order dynamical system, conditions for passivity and losslessness are formulated in terms of properties of the state equation function, the output function, etc. These conditions can be verified without solving the state equation, and can be viewed as non‐linear generalizations of the well‐known time‐domain and frequency‐domain passivity and losslessness conditions for linear time‐invariant lumped n‐port networks.
Computer‐Aided partial synthesis of lossless non‐uniform lines of finite length
Authors: Chen Y. M. , Weng X. T. 
Published: July 2007

AbstractA computer‐aided method for solving the problem of partial or one‐parameter synthesis of a lossless non‐uniform transmission line of finite length is presented. This method is essentially the same as the pulse‐spectrum technique for solving the inverse problems of determining the velocity coefficients of the wave equation from known information of the solution on the boundary. The basic idea of this method is that the original synthesis problem in the time‐domain is first reduced to a CW synthesis problem in the frequency‐domain, by either Fourier transform or Laplace transform, and then the synthesis is carried out in the frequency‐domain by using an iterative numerical algorithm. Numerical simulations are carried out to test the feasibility and to study the general performance of this computer‐aided synthesis procedure without the real design data. It is found that this computer‐aided method does give excellent results.
Finding all solutions of piecewise‐linear circuits
Authors: Chua Leon O. , Ying Robin L. P. 
Published: July 2007

AbstractA new algorithm is given for solving the d.c. piecewise‐linear equations of non‐linear electronic circuits. The device models are assumed, with little loss of generality, to be made of 2‐terminal piecewise‐linear resistors and linear controlled sources. Unlike other methods, this algorithm guarantees that all solutions will be found in a finite number of steps. The method depends crucially on a recent development which allows a multi‐dimensional piecewise‐linear function to be represented in a closed canonical form. This highly compact representation requires only a minimum amount of computer storage and is responsible for the efficiency of the algorithm.
Non‐Recursive adaptive impulse noise canceller
Authors: Kazovsky Leonid G. , Turgeman Eli 
Published: July 2007

AbstractA non‐recursive adaptive impulse noise canceller (AINC) is investigated. The AINC is designed to suppress long impulsive interferences which are a primary source of errors in many communication systems. Performance of the AINC depends upon the input filter of the receiver. It is shown that the optimum input filter is LPF; the optimum LPF bandwidth exists which provides the minimum error rate of the receiver. The system error rate is studied by means of a computer simulation. Simulation results indicate that the AINC provides a very effective suppression of impulse noise. However, conditions in a real communication channel may be quite different from those chosen for simulation. Therefore, further research remains to be done before the AINC can be recommended for practical applications.
Fault diagnosis in non‐reciprocal networks
Authors: Plotkin E. , Roytman L. M. , Swamy M. N. S. 
Published: July 2007

AbstractBased on the theorem concerning the maximum number of independent simulations in an m‐port together with Tellegen's theorem, some methods are proposed for the determination of the values of the faulty elements. These methods require a minimum number of measurements at the external nodes of the circuit. A numerical example of the application of such a method is given.
Generalized second‐order active R filters
Authors: Nedungadi A. , Venkateswaran S. 
Published: July 2007

AbstractA generalized treatment of second‐order active R filters is presented. A general circuit configuration is derived whose transfer functions are expressed in terms of defined resistive transfer functions and the gains of two operational amplifiers. The general network uses fewer resistances than reported configurations and can be used to realize all second order functions including oscillators. This approach facilitates simple and systematic analysis of second‐order active R networks and leads to configurations having minimum component count.
On the passivity criterion for lti N‐ports
Authors: Boyd S. , Chua L. O. 
Published: July 2007

AbstractExisting proofs of the passivity criterion for linear, time‐invariant, distributed N‐ports are either incorrect or too involved, requiring the use of advanced mathematics such as distribution theory. This paper presents a simple but completely rigorous proof using only basic real and complex analysis. For the sake of completeness we have included simple proofs of the Paley‐Wiener theorem and the Poisson formula for the half plane. We show that solvability, a non‐intuitive technical assumption made in rigorous theories of LTI passive networks, is virtually always satisfied. Finally, we give a passivity criterion applicable to N‐ports described by general co‐ordinates, from which passivity criteria for any specific representation (e.g. impedance, admittance, hybrid, transmission, scattering, etc.) can be trivially derived.
Optimum flat delay filter characteristics
Authors: Pang Khee K. , Kirton Paul A. 
Published: July 2007

AbstractThe problem of finding optimum filter characteristics that produce flat delay in the passband is formulated as a convex programming problem for minimum‐phase lowpass filters. The flatness of the group delay is indicated by an error norm, which is a measure of the deviation of delay characteristic from a constant reference level. When the attenuation specifications are relaxed, it is possible to achieve a constant delay characteristic and the problem is solved analytically. When the attenuation constraints are too tight to achieve the constant delay characteristic, the problem is solved numerically. If the least squares error criterion is used, the problem is a quadratic programming problem. It reduces to a linear programming problem for the minimax criterion. Some resulting optimum attenuation characteristics and their associated error norms are given. The tabulated error norms represent the lowest theoretical limits that lowpass, minimum‐phase filters can ever attain. This is confirmed by comparing the limits against the performance of some well‐known filters.
High frequency active‐R filters
Authors: Bermudez José Carlos M. , Calôba Luiz P. 
Published: July 2007

AbstractLimitations on active‐R filter pole displacements are studied. the maximum magnitude of the natural frequencies is presented as a function of the op. amp. GB. Structures to realized biqads with two op. amps. and a predistortion technique, to take into account the amplifier's high frequency pole, are proposed. Experimental results are presented which confirm the theory.
Simple solution curves of non‐linear resistive networks
Authors: Yun C. W. , Chao K. S. 
Published: July 2007

AbstractA generalized sufficient condition for the existence of a (unique) simple solution curve defined by fi(x1, x2,…, xn) = 0 for i = 1, 2. … n − 1 is developed. the condition is deduced based on a parametric representation of a solution curve. Modified networks having identical (n − 1) network equations are generated and topological criteria associated with the sufficient condition are obtained from the examination of modified networks.
On the dynamics of non‐linear RLC networks from a geometric point of view
Authors: Szatkowski Andrzej 
Published: July 2007

AbstractThe dynamics of non‐linear RLC networks is considered from a geometric point of view. the concept of the Kirchhoff‐Maxwell space is presented and next it is explored in the formulation of the equations of motion for a broad class of dynamic non‐linear networks. Linearized networks and eventually strictly passive networks are examined. Several new structural stability results are given.
Negative resistance devices
Authors: Chua Leon O. , Yu Juebang , Yu Youying 
Published: July 2007

AbstractTwo‐terminal devices which exhibit a type‐S (current‐controlled) or type‐N (voltage‐controlled) negative differential resistance can be built using only two bipolar transistors and linear positive resistors without any internal biasing power supply. Two general algorithms are presented in this paper for systematically generating all such devices. Hundreds of negative resistance devices have been derived to date using these algorithms and a selection of these circuits is presented in this paper along with their computer‐simulated v‐i curves. Laboratory measurements of a few sample circuits agree remarkably well with the computer‐simulated results.
High‐order non‐linear circuit elements: Circuit‐theoretic properties
Authors: Chua Leon O. , Szeto Ellen W. 
Published: July 2007

AbstractHighei‐ and mixed‐order non‐linear circuit elements have been introduced to provide a logically complete formulation for non‐linear circuit theory. In this paper, we analyse the circuit‐theoretic properties of these elements, including reciprocity, passivity and losslessness. We have derived necessary and sufficient conditions for a higher‐ or mixed‐order n‐port element to be reciprocal or antireciprocal. We have shown that under very mild assumptions, most non‐linear higher‐order 2‐terminal elements are active and not lossless. Finally, we show that the number of lossless linear higher‐order 2‐terminal elements far exceeds that of the passive linear elements.
An efficient numerical derivation of group delay characteristic from prescribed characteristic function
Authors: Kida Takuro , Kurogochi Katsumi 
Published: July 2007

AbstractThis paper proposes an efficient method of deriving the group delay characteristic only from the prescribed characteristic function of a resistively terminated LC 2‐port network with the aid of a special numerical integration technique. As a by‐product of the method, the transfer function of the network can also be derived. the idea of the method is based on the Hilbert transform relation between the attenuation and phase of the minimum‐phase polynomial. A simplified Hilbert transform relation is presented which avoids the improper integral of its original form. the analysis of the error due to the numerical integration applied in the method and the comparison with a conventional method concerning execution time and accuracy are included.
New sensitivity measures for resistively terminated LC filters
Authors: Kida Takuro , Kurogochi Katsumi 
Published: July 2007

AbstractTwo new sensitivity measures for resistively terminated LC filters with arbitrary network structures are proposed. One gives an upper bound of the absolute sum of the second‐order sensitivities of the operating propagation attentuation function with respect to the reactive elements. This measure, however, is based on the supposition of the invariance of the attenuation poles. the other gives an upper bound of the absolute sum of the first‐order sensitivities of the group delay characteristic with respect to the reactive elements. Both the measures can be evaluated only from the prescribed characteristic function of the network. Some examples are included which show the utility of these measures for designing filters with favourable statistical tolerance in the passband.
Efficient computer analysis of ideal switched‐capacitor circuits using matrix compaction techniques
Authors: Claesen Luc , Vandewalle Joos , de Man Hugo 
Published: July 2007

AbstractIn this paper we describe how three simple observations can be used in order to obtain an efficient algorithm for the computer analysis of ideal switched‐capacitor circuits. the resulting algorithm is linear in the number of phases. the first observation uses the structure of the r‐domain MNA‐matrix to come up with a new LU‐decomposition scheme which is gradual per timeslot. the second observation allows a great reduction in size of the z‐domain MNA‐matrix by a matrix compaction algorithm which also operates gradually per timeslot and which can be interleaved with the first gradual LU‐decomposition process. This leads to a small matrix which can then be used for a time‐ and direct frequency‐domain analysis. Third, the computations of transfer functions, aliasing functions and sensitivities can be optimized by applying appropriate excitations and making appropriate combinations of the terms in the expressions. These algorithms have been implemented in the SC‐analysis program DIANA.SC. the usefulness and efficiency of the program is then illustrated with some examples.