bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the number of conductances required for realizing Y and K matrices
Authors: Naidu M. G. G. , Reddy P. S. , Thulasiraman K. 
Published: July 2007

AbstractUpper bounds are established on the number of conductances required for realizing a real symmetric matrix Y as the short‐circuit conductance matrix of a resistive n‐port network containing no negative conductances, and for the realization of a real matrix K as the potential factor matrix of a similar network without negative conductances. These results are the consequence of the properties of the modified cut‐set matrix of an n‐port and a theorem in the theory of linear programming.
Resonant decoding for a class of nonsinusoidal microwave signals
Authors: Jackson J. Russell 
Published: July 2007

AbstractTransmission‐line cascades are shown to exhibit the properties of a generator and resonance detector for a class of nonsinusoidal microwave signals. In providing a strong analogy to a well‐known phenomenon in the sinusoidal domain, this generator‐resonator matching is suggestive of possible applications in communications‐systems technology.
A class of nonrational impedances
Authors: Belevitch V. 
Published: July 2007

AbstractThe hypergeometric function p−1F(1, b; c; −p−2) is a positive real function of p for all real values of the parameters satisfying c ≧ b ≧ 0. The corresponding impedance is realizable as an LC‐ladder beginning with a unit shunt capacitance. The behavior on the j‐axis of this class of impedances is analysed.
A new single operational amplifier active RC bandpass network with reduced sensitivity to amplifier gain‐bandwidth product
Authors: Soliman Ahmed M. 
Published: July 2007

AbstractA new configuration for realizing a low sensitivity active RC bandpass filter suitable for hybrid integrated realization is given. The network consists of a single operational amplifier (OA) and two identical passive RC bandpass building blocks. The active element sensitivities are given. The frequency limitation equations of the filter based on the one‐pole rolloff model of the OA are derived. It is found that the choice of the element ratios of the passive RC networks plays an important role in the overall performance of the active resonator. Two cases are discussed in detail: one has the advantage of having better element ratios, and the other has the advantage of having lower sensitivities. The given network is less sensitive to the amplifier' gain‐bandwidth product than other low sensitivity active RC bandpass networks using two operational amplifiers.
Generalized interdigital filters made of multilayer striplines
Authors: Jokela Kari 
Published: July 2007

AbstractIn the first part of this paper is presented a relatively simple loss analysis method for many coupled line structures. The corresponding equivalent circuit consists of uncoupled lossy transmission lines whose parameters are determined relatively easily without a complex numerical field analysis by using fringing‐capacitance curves for rectangular strips. In the narrowband case further approximations are possible. The increase of the accuracy is most significant if the couplings between strips are tight.In the second part a realization of the generalized interdigital filter using a multilayer structure consisting of polyphenyleneoxide plates is discussed. The repeatability of the filters is improved with the aid of thin polyethylene films. The shorts are made by the copper coating that also effectively suppresses higher‐order modes. The fine tuning of the filter can be made by tuning screws. The improvement of the design accuracy without tuning elements using a computer simulation is also discussed. Finally, the effects of the losses are studied, connecting the loss analysis presented with ring resonator measurements.
Characterization theorems for bounded and positive two‐variable functions
Authors: Delsarte Ph. , Genin Y. , Kamp Y. 
Published: July 2007

AbstractThe aim of this paper is a two‐variable extension of some classical results by Carathéodory and Schur, characterizing the classes of positive and bounded analytic functions. It is shown how these functions can be approximated by a convergent sequence of polynomials of the same class. The particular case where bounded two‐variable functions reduce to rational inner functions is described. As an application, the integral representation of positive functions is used to generate the complete family of two‐variable reactances of the first degree.
Approximation of fir digital filters by bilinear transformation
Authors: Sallai Gy. 
Published: July 2007

AbstractThe approximation of the finite‐impulse‐response (FIR) digital filters using the bilinear transformation of a restricted class of the rational functions is considered. The reference rational functions are constructed for maximally flat selective and quadrature filters. The proposed method can be directly used for both even and odd degree filters, and yields simple explicit expressions for the filter coefficients.
Intermodulation distortion in uhf transistors
Authors: Stewart R. D. , Kasim T. A. 
Published: July 2007

AbstractIntermodulation distortion in transistors operating between 1 and 2 GHz has been studied. Four sources of nonlinearity in the transistor were examined and characterized by polynomials which were expressed in terms of the voltages at the transistor junctions. By incorporating these nonlinearities into a linear model, a nonlinear UHF transistor model was derived. The nodal equations of this nonlinear model were successively solved by expressing each nodal voltage in terms of a Volterra series expansion of the input voltage. Based on this analysis, predictions of the intermodulation distortions in two types of transistor were made; these predictions compared favourably with meansurements.
An optimum approximation for the interchange of a second‐order transfer function by a transfer function with decreased pole Q‐factor
Authors: Filanovsky I. M. , Stromsmoe K. A. 
Published: July 2007

AbstractThis article presents a method for the interchange of a second‐order circuit with high Q‐factor poles by a more complicated network that consists of several low Q‐factor stages. The ratio of the substituting circuit transfer function to the given second‐order transfer function approximates unity with a minimum deviation over the whole jw‐axis. The method is applicable to all types of second‐order transfer functions with arbitrary zero locations. The approximation error decreases in a geometric progression with the number of low Q‐factor stages. A method for determining the poles and zeros of the approximating transfer function is described and examples of interchanging are given.
Explicit design formulae for wideband bandpass filters
Authors: Rhodes J. D. , Al‐Jadir S. J. 
Published: July 2007

AbstractA new design technique is developed for the realization of wideband bandpass filters synthesized in the form of a lowpass filter cascaded with a highpass filter. For the maximally flat and chebyshev response cases, approximate explicit design formulae are provided to allow a direct design technique to be used.Results obtained by using this design technique agree with those obtained by direct synthesis and offer a significant improvement over the direct lowpass—highpass cascade obtained by frequency scaling.
Optimization of large change tolerances of linear integrated circuits
Authors: Filipkowski Andrzej , Tue Le , Michalski Zdzisław 
Published: July 2007

AbstractOptimization of element tolerances is a very important but also time consuming part of integrated circuit design. In this paper an algorithm is presented for the worst case optimal assignment of large change tolerances, in which a significant simplification of the problem is obtained for a class of linear circuits. This is due to taking advantage of the bilinear dependence of the network functions on element values and to some simplifications assumed. The minimal cost of the circuit is the objective function.
Exact analysis of inhomogeneous ladder networks having a tridiagonal interaction matrix
Authors: Haley Stephen B. 
Published: July 2007

AbstractA projection‐recurrence method is applied to active and passive ladder networks with a tridiagonal interaction matrix to obtain a factorization of the response functions. The factors are partial chain parameters, determined by third order recurrences. For a ladder with N nodes, the number of arithmetic operations to calculate response functions ranges from 4N to 6N. A diagrammatic representation is developed for passive ladders which makes it possible to obtain the partial chain parameters by inspection, and a compact formula for the node‐voltage response is presented for active doubly‐terminated ladders.
A new method of inhomogeneous ladder network synthesis
Authors: Brown David P. 
Published: July 2007

AbstractA procedure to synthesize ladder networks in which each series arm impedance is fiz(s) and each shunt arm admittance is giy(s) is presented. Given a specified network function T(s), the function G = z(s)y(s) is first established by a polynomial decomposition. Then the appropriate chain parameters associated with T(s) are constructed as polynomials in G. The constants fi, gi are determined from a straightforward continued fraction expansion of a related RL impedance function in G. Necessary and sufficient conditions for the steps in the procedure are established and examples are included.
Multiloop feedback unsymmetrical active filters using quads
Authors: Gonuleren Ali Nur 
Published: July 2007

AbstractIn this paper, a general design procedure for high order unsymmetrical active filters is presented using a special configuration of quads. Quads are 4th order subsection blocks using biquads in a special manner. It is shown that the determination of network parameters is not dependent on frequency range, and that the design procedure is simpler than other multiloop feedback (MF) topologies. The transmission zeros of the transfer function are derived directly from the zeros of the biquadratic blocks and thus feedforward or summation techniques are not required.
A comparison of semiconductor controlled sources for the design of active rc impedances
Authors: Brugger U. W. , Leuenberger R. , Hosticka B. J. , Moschytz G. S. 
Published: July 2007

AbstractA feasibility study of the four types of controlled sources realized in bipolar form is undertaken. The results are used in designing a PCM lowpass filter of which the total amplitude variance due to passive and active non‐idealities is minimized. The circuit yield is determined using Monte Carlo simulation.For this particular application, a comparison shows preferable behaviour using transimmitances (e.g. operational transconductance amplifiers) than using gain elements such as the opamp.
An efficient method of statistical analysis for LC ladder filters
Authors: Kida Takuro , Kurogochi Katsumi 
Published: July 2007

AbstractNew tolerance measures for lossless or dissipative ladder filters and their numerical evaluation procedures are proposed. The proposed measures provide the approximate values of the statistical mean and variance of the variation of the operating propagation function or characteristic function in nepers. These measures are derived by utilizing a first‐ to fourth‐order Taylor series approximation and can be evaluated easily by a series of simple algebraic operations. Simple formulae are also presented which estimate the error incurred by the neglected terms of this Taylor series approximation.
When is a device passive?
Authors: Moylan P. J. , Chua L. O. , Szeto E. W. 
Published: July 2007

AbstractPassivity is perhaps the most basic concept in circuit theory. Unfortunately, the existing definitions of passivity are too restrictive and often contradict one another. In this paper, a new passivity definition is proposed which is applicable to all n‐port and (n + 1)‐terminal devices—including time‐varying, non‐linear, and distributed circuit elements. This definition generalizes and reconciles several recent conflicting definitions.
Loop equation formulation for switched capacitor networks containing nullors
Authors: Bruton L. T. , Bailey G. R. , Battacharjee G. 
Published: July 2007

AbstractA method is given for determining the loop equations of an ideal active switched capacitance (SC) network containing switches, capacitors and nullors. These equations are obtained directly by row‐column operations on the passive unswitched loop elastance matrix. the results are extended for the P‐ phase case. It is shown that the loop charges can be solved for and that the branch voltages can be obtained from the loop charges.
The solvability and monotonical properties of a certain class of D.C. non‐linear networks
Authors: Tadeusiewicz Michal 
Published: July 2007

AbstractThe problem of the existence and uniqueness of solutions for a certain class of non‐linear networks, including locally active elements and controlled sources, is considered in the paper. the conditions under which the input characteristics of the network are monotonically increasing are also analysed. Two theorems relating to the problem in question, containing some results in terms of the network topology, are formulated.
Detection of harmonic burst signals
Authors: Simon Gy. 
Published: July 2007

AbstractThe proposed procedure and the corresponding circuits for the recognition of a frequency from a set of possible input frequencies in the frame of a time‐window interval seem to be advantageous as they lead to simpler hardware than the well‐known energy detector. A unique feature is the single channel processing possibility. In addition the decision on the presence or absence of a given frequency is much faster than with a filter bank of resonators in a nearly lossless resonators. the frequency response is however not monotonic in frequency but has a somewhat periodic shape. the cases of the real lossy or unstable circuits are also dealt with. Some aspects of circuit realizations are given.
Subharmonic phase‐lock criteria for a class of weakly non‐linear high‐order oscillators
Authors: Calandra E. F. , Sommariva A. M. 
Published: July 2007

AbstractSubharmonic frequency entrainment of high‐order weakly non‐linear oscillators is investigated. For the class of circuits considered, equations are first derived which provide the first approximation values for the amplitudes and phases of the two main spectral components of the steady‐state waveform. Necessary and sufficient stability criteria are then derived in explicit from.The example worked out (a negative conductance double‐tuned oscillator) shows the efficiency and ease of use of the proposed method.
A multiplier‐free dft algorithm using differential coding of coefficients
Authors: Kocsis Ferenc 
Published: July 2007

AbstractThe proposed procedure is a new, practically multiplier‐free DFT algorithm which is especially suitable for the computation of longer transforms. the method is based on the realization of prime‐length transforms using a single kind of optimized FIR filter. the transform coefficients have been coded differentially and the approximation is signal independent. the accuracy has been characterized by the ratio of the squared sum of the DFT coefficients and the squared sum of the errors of the approximating coefficients. the algorithm producing the approximate sequence is simple, its computational and memory requirements are minimal. and finally, for some transform lengths the characteristics of the algorithms have been derived.
Uniqueness of the asymptotic behaviour of autonomous and non‐autonomous, switched and non‐switched, linear and non‐linear systems of dimension 2
Authors: Azzouz Abdennasser , Hasler Martin 
Published: July 2007

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 between N matrices 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, is given.
Dynamic partitioning method for piecewise‐linear VLSI circuit simulation
Authors: Tejayadi O. , Hajj I. N. 
Published: July 2007

AbstractThis paper presents a method for dynamically partitioning circuit equations for time‐point relaxation‐based electrical circuit simulation techniques. the non‐linear element characteristics are approximated by piecewise‐linear (PWL) functions. the dynamic partitioning is carried out at every iteration during the solution process by comparing integers representing region numbers in the PWL functions, and only those PWL elements that change regions are involved in the repartitioning process. In many instances the circuit is automatically partitioned into completely d.c.‐disconnected subcircuits, which result in speeding up the convergence of the relaxation process. the approach has been implemented in a computer program for transient analysis of MOS VLSI circuits. Computational speeds of two orders of magnitude or more as compared to standard circuit simulation have been observed in solving small circuits on a serial computer without much loss in accuracy. the speed improvement is expected to be higher as the size of the circuit increases. Simulation using the dynamic partitioning method on a parallel computer indicates an efficient use of the processors, and corresponding improvement in speed.
Analysis of the optimal double side‐band converter
Authors: Belevitch Vitold 
Published: July 2007

AbstractThe optimal double side‐band converter, a novel circuit briefly presented in a previous paper,' is a rectifier bridge operating between selective terminations and containing an infinite number of resonant circuits. the circuit performance was justified by considering a finite number of resonant circuits and then letting that number become infinite. This limit process was erroneously handled, and is now corrected, so that the results for the infinite circuit (which were correct) are rigorously validated.
Dynamics of the inclusions appearing in the return maps of chua's circuit I. The creation mechanism
Authors: Kahlert Claus 
Published: July 2007

AbstractThe island‐like inclusions that appear inside the range of the return map in Chua's circuit are investigated further. the condition for the creation of a new inclusion is shown to be closely related to the selection rule for the critical curve ø. Moreover, a solution of this problem can also be given in terms of λ, the boundary of the return map's domain, and so in simpler form. the phases of the special trajectories that mark the creation of an inclusion turn out to be virtually invariant through all values of the canonical parameter ρ. Moreover, the phase difference between subsequent creations appears to be close to a constant too. This fact allows one to formulate explicit expressions for the limiting behaviour of the creation curves.
A serial charge redistribution logarithmic A/D converter
Authors: Lefas C. C. 
Published: July 2007

AbstractThe present paper describes the design and prototype construction of a serial charge redistribution logarithmic A/D converter (LADC). the LADC uses only two capacitors and has an eight‐bit digital word. It directly converts the input to logarithmic code and is suitable for use with digital systems implementing the sign‐log number system. the conversion is completed in 128 steps (clock cycles). the input dynamic range is four decades and the relative error is 3.7 per cent. A capacitor ratio accuracy of 0.4 per cent is required to keep conversion errors within 1 LSB.
Sc filters based on scattering parameters
Authors: Limperis A. , Haritantis I. 
Published: July 2007

AbstractA systematic method for the simulation of LC ladders and unit‐element filters by means of switched capacitor (SC) circuits is proposed. the method is based on the use of wave equivalents of various two‐port subnetworks which are now realized by the same type of SC symmetric subcircuits. These subcircuits serve as the structural unit‐blocks for realizing high‐order circuits. Parasitic‐free circuits of practical interest can be developed. Examples of high‐order circuits are given. This wave method is simple in its concept and also in the circuit design. Through the alternative solutions which are described, the flexiblity of the method is demonstrated.
Some fundamental properties of second‐order active RC filters with composite operational amplifiers
Authors: Urbaś Aleksander , Osiowski Jerzy 
Published: July 2007

AbstractSecond‐order active RC filters employing N identical operational amplifiers (OAs) are considered. the way to achieve the highest‐order zero sensitivities of the dominant poles is shown. It leads to composite operational amplifiers (COAs) with a gain function of a polynomial form. the analysis of sensitivities, errors and location shifts of dominant poles as well as the effects of parasitic poles is also provided. the results have been confirmed by numerical analysis and an experimental verification.
On weak completeness and weak non‐degeneracy of networks
Authors: Milić Mirko M. , Novak Ladislav A. 
Published: July 2007

AbstractThe graph‐theoretic properties depending on the element types and their controllability but not on the particular form of constitutive relations of elements are considered. New concepts such as normal partition pair of the branch set, weak completeness and weak non‐degeneracy are introduced and their properties are investigated in detail. These properties may then be used to formulate purely topological methods of analysing some dynamical aspects of nonlinear RLC networks.
Improved description of base dynamics in the modelling of bipolar transistors
Authors: Sipilä Markku , Porra Veikko , Valtonen Martti 
Published: July 2007

AbstractAn improved non‐linear high‐frequency model for the bipolar transistor is presented, based on considerations of the dynamics of the charge stored in the base region. the model incorporates higher‐order circuit elements in order to obtain increased accuracy in circuit simulation at high frequencies. the model is derived from device physics by solving the diffusion equation in the base region by means of a quasi‐static expansion. the result is a more accurate circuit representation, which can be added to existing bipolar transistor models. Simulation examples are given and the possible convergence problems associated with the model are discussed.
Periodic, intermittent and chaotic states of clocked autonomous digital systems
Authors: Deane J. H. B. , Jefferies D. J. 
Published: July 2007

AbstractThe one‐dimensional full return map for the repetitively triggered monostable multivibrator is derived analytically and some of its properties under iteration by computer are investigated. It is found that the monostable can exhibit periodic, intermittent and chaotic behaviour as the triggering frequency is varied. the predictions of the theory are verified experimentally, suggesting that such methods may be used with confidence as a design tool.