bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unique solvability and order of complexity of linear networks containing memoryless n‐ports
Authors: Recski András 
Published: July 2007

AbstractEssentially combinatorial necessary and sufficient conditions are given for the unique solvability of linear networks containing memoryless n‐ports, and for the existence of a hybrid immittance description of the interconnection of such n‐ports. Formulae for the maximum number of independent state variables and order of complexity are also presented.The essential tool for obtaining the results is the theory of matroids. The conditions can be effectively checked by matroid partition or intersection algorithms.Throughout, the ‘general’ approach is considered, i.e., no cancellation among the nonzero terms is allowed. The results are illustrated by several examples.
Microwave filters with nonperiodic transmission characteristic
Authors: Arndt F. , Saulich G. 
Published: July 2007

AbstractA microwave filter with nonuniform‐coupled transmission lines is suggested. In contrast to known transmission‐line microwave filters the transmission characteristic does not change periodically with frequency. The synthesis procedure shown reduces the design problem to the known synthesis of directional couplers with nonuniform coupling factor. A table of calculated coupling factor values of the microwave filter with an equi‐ripple passband of 0.05 dB up to 1 dB and an equi‐ripple stopband of 60 dB is given. A practical design example shows good agreement with theoretical results.
Computer‐aided design of stable recursive digital filters from magnitude specifications
Authors: Prasad K. P. , Reddy P. S. 
Published: July 2007

AbstractThis paper presents a method of designing one‐ and two‐dimensional recursive digital filters making use of the properties of bilinear transformation of strictly Hurwitz polynomials. The result is a stable digital filter in both one‐ and two‐dimensional cases, which requires no further testing for stability. The well known unconstrained minimization technique of Fletcher—Powell is used, making use of a transformation of optimization parameters to satisfy the mild constraints of stability. This method is considered to be more efficient on an overall basis than the existing lp design technique of Maria and Fahmy. Nor does it rely on Deczky's theorem to ensure a stable filter which may sometimes lead to unstable solutions in the two‐dimensional case. An example is provided illustrating the method.
A refined classification of single amplifier filters
Authors: Sedra Adel S. , Brown Les 
Published: July 2007

AbstractIt is shown that Single Amplifier Biquads (SAB's) may be grouped into two major categories, the Enhanced Negative Feedback (ENF) and the Enhanced Positive Feedback (EPF). These two major classes of circuit are related by the complementary transformation and hence exhibit identical sensitivity performance. In the extreme, the ENF class degenerates to the familiar Negative Feedback (NF) class while the EPF class reduces to the Positive Feedback (PF) case where the op amp is connected in a unity‐gain configuration. Depending on the order of the RC feedback network, each class includes two subclasses with different sensitivity performance. The paper examines in detail the ‘enhanced feedback’ mechanism, and investigates the optimum design of the Deliyannis—Friend circuit and its complement the Sallen and Key positive feedback configuration.
On the interchanging of the second‐order network with high Q‐factor poles by low Q‐factor stages
Authors: Filanovsky I. M. , Stromsmoe K. A. 
Published: July 2007

AbstractThis article presents a method for the interchange of a second‐order network with high Q‐factor poles by a more complicated network that consists of several low Q‐factor stages. The transfer function square modulus of this new network approximates in a Chebyshev manner the square modulus of a given transfer function if the zeros of a given network are complex conjugate and not located on the α‐axis. In the other cases an error of the square modulus approximation is a Chebyshev kind also, but with the weight that depends on the zero locations of the given second‐order network and given maximum Q‐factor. It is shown that all low Q‐factor pairs of the poles must coincide when we apply the proposed method directly. The approximation error decreases in a geometric progression with the growth of the number of low Q‐factor stages. A method for determination of the numerator zeros of the approximating transfer function is described and examples of interchanging are given.
Selective, constant delay wave digital filters
Authors: Denton G. , Carlin H. J. 
Published: July 2007

AbstractA wave digital filter design method is discussed which produces good selectivity and flat delay characteristics. The filter is designed in the microwave domain with monotonic stopband response using Carlin and Wu's technique for minimum‐phase linear phase commensurate line transducers, then realized in the digital domain with Fettweis relations. A comparison is made of frequency response sensitivity to multiplier coefficient truncation between this wave filter and some FIR's, all with approximately the same number of multipliers. The cascade realizations of the FIR's show considerable passband amplitude response deterioration due to coefficient truncation, whereas the direct realizations for the FIR's show significant deterioration of stopband amplitude response owing to coefficient truncation. Coefficient truncation for the wave digital filter caused relatively small deterioration of both passband and stopband amplitude responses as well as small distortion of the flat delay characteristic in the passband.
Synthesis of active RC‐biquads using generalized immittance converters
Authors: Nenov Georgi A. 
Published: July 2007

AbstractThis paper considers a new nullor structure of a current‐inversion generalized immittance converter and its application. On the base of generalized continuants a method for synthesis of active RC‐sections with biquadratic voltage transfer functions (biquads) is developed. The structures obtained contain current‐inversion generalized immittance converters and passive RC‐elements. The synthesis procedure is illustrated by examples and experimental results.
Critical element analysis for the transfer, gain and phase functions in linear active filters
Authors: Acar Cevdet 
Published: July 2007

AbstractIn linear active filters, the element criticalness, the most and the least critical elements, and also optimum tolerances have been defined for transfer, gain and phase functions. Simple and systematic procedures for computing their values, thus determining the ordered hierarchy of critical elements, are provided. Moreover, as an example, the element criticalness, the most and the least critical elements, and the optimum tolerances have been evaluated for Gopal's network realizing the third‐order Butterworth characteristic and using equal‐valued capacitors and resistors.
Third order oscillators with independently adjustable frequency, amplitude and transient response
Authors: Owen Earle W. 
Published: July 2007

AbstractA class of third order harmonic oscillators with frequency, amplitude and transient response controlled by three separate sets of parameters is derived. A simplified group of oscillators is described in which there are only three parameters, one which controls the frequency, another the amplitude, and the third the transient response. Each oscillator contains a single nonlinearity, which can be either of the saturation or the dead space type. The mathematical analysis is based on linearizing the nonlinearity by means of the sinusoidal describing function. The transient response is studied by considering small amplitude perturbations away from the oscillator's limit cycle. The results of analogue computer simulations are presented with emphasis on the relationship between transient response and the gain controlling it.
Optimal printed circuit board ordering via hart‐nilsson‐raphael‐algorithm
Authors: Sangiovanni‐Vincentelli Alberto L. , Santomauro Mauro 
Published: July 2007

AbstractA layout problem, the optimal ordering of printed circuit boards equally spaced on a straight line, is investigated. An optimal algorithm whose structure is based on the Hart, Nilsson and Raphael algorithm is presented and its complexity evaluated. Since the intrinsic complexity of the problem is shown to be very high, an approximated algorithm is introduced and its performances are evaluated. Experimental results are discussed to emphasize the efficiency of the approximated algorithm.
A tableau approach to power system analysis and design
Authors: Director S. W. , Sullivan R. L. 
Published: July 2007

AbstractThe tableau formulation of electronic circuit equations has been shown to be an efficient and useful formulation for circuit optimization. In this paper a tableau based formulation of the static power‐flow equations for a power system is presented. Because of the explicit appearance of all quantities of interest the tableau formulation allows the general statement, and solution, of a variety of power system optimization and design problems without the need to resort to restrictive assumptions.
On obtaining of a transfer function with complex‐conjugate poles of the same Q‐factor by fourier approximation
Authors: Filanovsky I. M. , Stromsmoe K. A. 
Published: July 2007

AbstractThis communication presents a method for obtaining a transfer function with multiple complex conjugate poles. The procedure is based on a special frequency transformation. The function derived from those to be approximated is expanded in a Fourier series with a finite number of terms. The application of the inverse transformation to this truncated series gives an algebraic ratio from which the transfer function with chosen poles can be obtained with known methods.
A theory of Q‐reciprocal and quasi‐reciprocal multiports
Authors: Osiowski Jerzy , Morawski Tadeusz 
Published: July 2007

AbstractTwo notions: quasi‐reciprocity and Q‐reciprocity as generalizations of classical reciprocity are introduced and examined for the multiport case. A number of theorems and properties characterizing a class of Q‐reciprocal multiports are stated. A way of extending to quasi‐reciprocal networks some results proved under the assumption of reciprocity is presented as an example of application.
Effect of operational amplifier imperfections on single amplifier filters
Authors: Soundararajan K. , Ramakrishna K. 
Published: July 2007

AbstractA general method is given for the analysis of single amplifier RC‐active filters using nonideal operational amplifiers (OA). It is shown that the output resistance of the OA has a significant effect in the passband and stopband in addition to the known deviations due to the finite gain—bandwidth product. The nonideal transfer functions in the factorized form, giving clearer concept of the effects of the nonideal OA, are obtained using some realistic approximations based on the typical specifications of modern general purpose OA. Expressions thus obtained closely follow the exact transfer functions, as demonstrated in the illustrative examples given, and their validity is confirmed by the experimental results.
Narrow‐band stripline filters with transmission zeros at finite frequencies
Authors: Jokela Kari 
Published: July 2007

AbstractA design method is described to realize narrow‐band stripline or microstrip bandpass filters having one transmission zero near to the upper and lower bandedge. The filters utilize capacitively coupled open half‐wave TEM‐line resonators. Two nonadjacent resonators are also inductively coupled. No short circuits are needed.The design is based on the approximate or exact synthesis of the lowpass protoype presented by Levy. The transmission line parameters are obtained easily from the design formulae which have been derived using the susceptance (or reactance) slope parameter technique. The filter performance is good up to 12 per cent bandwidth. Measured results show good agreement with the theoretical ones.
Frequency‐dependent OP‐AMP gain influence on parameters of the single amplifier biquad filters
Authors: Reljin Branimir D. 
Published: July 2007

AbstractThe influence of the finite gain and gain‐bandwidth product of the operational amplifier on the parameters of the active RC filter has been investigated in the present paper. Single amplifier biquad filters were analysed for the case when the central frequency in the pole pair does not depend on the amplifier gain, i.e. when S = 0. The general results were obtained for such filters, describing well the filter behaviour at low as well as at high frequencies. On the basis of the results obtained, the deviation of the realized parameters from the desired values can be determined, and thereby the necessary correction of the filter calculation can be made. The experimental results agree well with the theoretical ones.
Notch filter based on identical building‐blocks with arbitrary transfer function
Authors: Plotkin E. 
Published: July 2007

AbstractA new design formula for the Multiple Frequency Notch Filter is proposed. The filter can be constructed from a finite set of identical linear sections with arbitrary transfer functions. The general transversal structure and the cascade connection of the identical linear section are considered. In contrast to the general structure, there are found three configurations which have only one adjustable element. An example illustrating the use of the proposed technique is included.
Sufficient conditions for the unique solvability of linear networks containing memoryless 2‐ports
Authors: Recski András 
Published: July 2007

AbstractCombinatorial necessary and sufficient conditions for the unique solvability of linear networks containing n‐ports are well known for the ‘general’ case. They are only necessary if relations among n‐port parameters are also taken into consideration.In the present paper combinatorial sufficient conditions are presented for linear networks containing RLC elements and memoryless 2‐ports. The somewhat surprising result is proved that whether a 2‐port can cause certain types of singularities can be predicted before the interconnection.A concept, similar to the normal tree (which intersects ideal transformers by one, gyrators by two or no edges) is introduced for arbitrary 2‐ports. Its existence implies unique solvability.Relations to previous results and algorithmical aspects are also discussed.
Propagation of constraints applied to circuit synthesis
Authors: De Kleer Johan , Sussman Gerald Jay 
Published: July 2007

AbstractA major component in the process of design is synthesis, the determination of the parameters of the parts of a network given desiderata for the behaviour of the network as a whole. Traditional automated synthesis techniques are either restricted to small, precisely defined classes of circuit functions for which exact mathematical methods exist or they depend upon numerical optimization methods in which it is difficult to determine the basis for any of the answers generated and their relations to the design desiderata and constraints. We are developing a symbolic computer‐aided design tool, SYN, which can be of assistance to an engineer in the synthesis of a large class of circuits. The symbolic methods produce solutions which are clear and insightful. The dependence of each parameter on the individual design desiderata and circuit constraints can be easily traced.
On the sensitivity analysis of digital filters
Authors: Liberatore A. , Manetti S. 
Published: July 2007

AbstractA very quick and simple algorithm for the overall evaluation of the sensitivity performance of a digital filter is introduced.To this end, it is shown that the sensitivity of the system function with respect to a given coefficient comes out equal to the output of a special digital network with unitary input. Having defined, then, an ‘overall sensitivity index’ as the sum of the various network sensitivities, it is shown that such an index can still be considered as the output of a digital network with unitary input. This network is composed of two subnetworks, identical to the original circuit, connected by a special set of branches.
Maximum flow in probabilistic communication networks
Authors: Nawathe S. P. , Rao B. V. 
Published: July 2007

AbstractThe purpose of this paper is to provide a general approach for the problems of analysis and synthesis of probabilistic communication networks. The flows in the branches of a network may be interdependent random variables having any arbitrary distribution.A simple technique, based on the theory of best linear prediction, enables Monte Carlo simulation of such a network. The simulation results suggest that the distribution of the maximum flow (that can be established in the network) can be approximated by a normal distribution despite the inapplicability of the central limit theorem. The results of Monte Carlo simulation are consistent with those obtained through an alternative analytical procedure.The synthesis problem considered in this paper is that of finding the branch capacities of a network so that a given demand for flow (specified in terms of its mean and variance), between a pair of vertices of interest, is satisfied. A direct search method (to find out the optimal branch capacity vector) enables simultaneous consideration of the first two moments of the maximum flow as against the existing ones which consider only the first moment.
The use of Padé approximants in the derivation of distributed low‐pass filters with simultaneous flat amplitude and delay characteristics
Authors: Fahmy M. F. 
Published: July 2007

AbstractA unified approach—based on Padé Approximants—is presented for the design of simultaneous equal constraints non‐minimum phase distributed filters. The results obtained indicate that this method is more general than previous methods, and allow considerable freedom for the control of both amplitude and delay. The procedure outlined can apply for any transfer function with arbitrary characteristics.
The existence and the determination of terminal equations for hybrid connected N‐ports
Authors: Sen A. Esref , Tokad Yilmaz 
Published: July 2007

AbstractA new procedure for the existence and the determination of terminal equations for the hybrid interconnection of two n‐port networks is given. It is shown that this procedure generalizes the previous works of Duffin, Trapp and Mitra for the hybrid sum of terminal impedance matrices which are either Hermitian positive semi‐definite (HSD) or arbitrary matrices with complex entries. For the application of the new procedure it is shown that each n‐port need not be terminal solvable or well defined. In fact, even in the case of active RLC n‐ports considered in sinusoidal steady‐state, the previous results of Duffin, Mitra and Trapp established for HSD matrices or arbitrary complex matrices can still be utilized with the use of modified terminal equations, to obtain the terminal equations of the resulting n‐port networks. It is also noted that the method introduced in this paper is independent of the choice of generalized inverses.
Synthesis of some non‐reciprocal filters employing the Jacobi polynomials
Authors: Jarry P. 
Published: July 2007

AbstractIn this paper, we establish that some of the generalized linear phase polynomials defined in Reference 1 are Hurwitz. The demonstration consists in showing that the ratio of two linear phase polynomials is a positive real function. The corresponding network interpretation with closed‐form element values is then given, which yields at the same time the reflection‐filter synthesis of the non‐minimum phase, non‐reciprocal transfer functions introduced in Reference 1.
D–T adaptor: Applications to the design of non‐linear N‐ports
Authors: Huertas J. L. 
Published: July 2007

AbstractA new network element is presented which can be of interest for synthesizing non‐linear n‐ports. It is shown that the use of n D–T adaptors reduces the problem to the synthesis of a multidimensional transfer‐characteristic (TC) plot. Some examples are given to show the applicability of the procedure and its ability to make a convenient use of integrated technology.
Compensation of frequency‐dependent amplifier non‐idealities in tunable RC‐active networks
Authors: Ferling Heinz‐Dieter 
Published: July 2007

AbstractA structure‐independent synthesis procedure for RC‐active networks, which performs the synthesis process by successive matrix expansion steps, allows the straightforward realization of networks with arbitrary tunable parameters. Since the desired behaviour of the realized circuit may be strongly affected by the frequency‐dependent imperfections of the active devices used for practical circuit construction, a compensation of the resulting root displacements of the network's characteristic equation is needed.The particular properties of the synthesis technique lead to an immediate relation between the root displacement caused by a single matrix transformation step and the information being available when this step is executed. Following a brief description of the synthesis process, this relation is derived and then used to establish a compensating circuitry which has to be added to the synthesized network structure in order to achieve the compensation effect required above.
Realizability conditions on short‐circuit conductance matrix by means of grounded active resistive networks embedding grounded VCVSs
Authors: Stamenković Borivoje B. 
Published: July 2007

AbstractThe proof is given of a new theorem concerning the minimum number of ideal grounded voltage‐controlled voltage sources (VCVSs) necessary and sufficient to realize an arbitrary real square matrix as the short‐circuit conductance matrix of a grounded transformerless active resistive multiport network embedding grounded VCVSs.
What does duality really mean?
Authors: Iri Masao , Recski András 
Published: July 2007

AbstractThe average network theorist answers this question by speaking about the interchange of the roles of voltage and current, while the average mathematician uses orthogonal vector spaces for his definition (as in mathematical programming, matroid theory, etc.). What is even worse, both of them believe that the two definitions are essentially the same. The main aim of the present paper is to show that this is the case for reciprocal networks only. Hence, in the theory of non‐reciprocal networks, two entirely different voltage‐current symmetries exist. We also show that both concepts are naturally related to the same, well known, duality principle of graph theory which also explains why nobody seems to have observed this phenomenon till now.
Modelling considerations and mean square error analysis for PSK data transmission
Authors: Henk Tamás 
Published: July 2007

AbstractCoherent PSK data transmission systems are modelled using matrices and non‐linear co‐ordinate transformations. A polyphase multiplier type demodulator with a new structure is suggested. A mean square error (MSE) analysis is carried out in the frequency domain for small perturbations which are linear distortions and static imperfections of the carrier and timing recovery, without any other restrictions for the bandwidth and the distortions. General and explicit expressions are given for the optimal carrier phase and timing delay, for their sensitivity and for the minimal MSE value. Using these expressions, filter design as well as carrier and timing recovery considerations are presented.