Showing papers on "Topology (electrical circuits) published in 1969"

Graph Theory and Social Networks: A Technical Comment on Connectedness and Connectivity:

Abstract: Concepts taken from graph theory and other branches of topology have been used by many sociologists and social psychologists, in particular Kurt Lewin and J. L. Moreno. Similar ideas have been used...

On the number of complete subgraphs and circuits contained in graphs

Abstract: and denote by KP the complete graph of p vertices . A well known theorem of TUR.áN [6] states that every 9(n ; m(n, p) + 1) contains a Kp and that this result is best possible. Thus in particular every á(2n ; n 2 + 1) contains a triangle. Denote by f„(p ; 1) the largest integer so that every W(n; m(n, p) + 1) contains at least fn(p ; l) distinct K p 's. RADEMACHER proved that fn(3 ; 1) = [n/2] and I proved [1] that there exists a constant 0 < c < z so that for every

Complementary-MOS low-power low-voltage integrated binary counter

Abstract: An integrated complementary MOS-transistor binary counter stage, particularly suited to low-power low-voltage applications, has been realized in monolithic form. The topology of the circuit allows one to group together all p-channel MOSTs and all n-channel MOSTs within two distinct surface areas. This feature results in an appreciable reduction of the surface necessary for a given circuit function. Dynamic current consumption is about 10 nA per kHz at a supply voltage of 1.35 volts. The complementary type of substrate is obtained by etching and epitaxially refilling wells in the original substrate material. Technological problems which had to be solved in order to achieve low-power low-voltage operation in complementary integrated MOS circuits will be discussed.

Computer-aided circuit design by singular imbedding

Abstract: We give a new and powerful method for the direct solution of circuit design problems. The method begins with a prespecified topology and some or all elements undetermined in value. The designer imposes on the circuit any desired set of node-pair voltages, branch currents, or driving point and transfer immittances. Values of circuit elements that satisfy the constraints are directly calculated. This direct method of solution avoids the usual iterative analysis-optimization schemes, reducing computer times by up to three orders of magnitude. A linear set of design equations is formulated by choosing undetermined element currents and node voltages as the variables. Singular elements are introduced to impose the desired constraints. Inequality as well as equality constraints are permitted. Element values are determined from the solution of these equations. In this paper we emphasize our method of solution in relation to dc networks.

General Purpose Programs for the Frequency Domain Analysis of Microwave Circuits

Abstract: This paper describes microwave circuit analysis programs techniques for general purpose which perform frequency domain analyses. Differing techniques used in two programs are described. The first uses transfer matrix analysis and is limited to networks having tree structured topologies and two-port devices such as transmission lines, stubs and lumped elements. It runs on a time-shared computer and is used for interactive design. The second program can analyze any linear network including those with multiport elements such as coupled transmission lines. This uses a nodal representation for the circuit and relies on inverting an admittance matrix to perform the analysis. In the first program the user describes his circuit in terms of topology as well as circuit elements. By this technique, a considerable reduction in computer size needed to run this program is effected. A 60 element circuit can be run on a commercial time-sharing service with less than 6K words of available core. The second program requires a large computer; for example, 32K words or core storage are required to analyze a 50 node circuit.

Flowgraph analysis of linear systems using remote time-shared computation

Abstract: Loops and paths in Mason signal flow graph of linear systems using algorithm with remote time shared digital computation

A sinusoidal voltage-controlled oscillator for integrated circuits

Abstract: This article describes an inductorless near-harmonic voltage-controlled oscillator circuit that utilizes a compensated Wien-bridge topology with a voltage-controlled Miller integrator as the tuning element. Suitable for monolithic integrated realization, the VCO offers a two-to-one control range for frequencies up to 10 MHz, with less than a 1-dB amplitude variation and less than a ten percent total harmonic distortion over the entire control range.

Computer Optimization of Recognition Networks

Abstract: This paper discusses optimization and implementation of recognition networks using interconnections of a standard network element to form a classification network. The standard element has a nonlinear transfer function whose inputs may be weighted by selected resistors. It is assumed that a training set of samples to be accepted or rejected is available but neither the a priori probabilities or the probability density functions of the measurements that describe the samples are known. The discriminant functions are formed from a given topology with unknown sets of weighting resistors assigned to the elements that constitute the classification network. Computer optimization is done using a hill-climbing technique that maximizes a function related to the miss rate and false alarm rate but requires neither an estimate or exact description of the sample probability space. A particular advantage is the one-to-one correspondence between the results of the optimization program and physical realization of the optimal recognition network. Disadvantages are due to the fact that an optimum can be found only with respect to a given topology and that the optimization algorithm may prematurely terminate on a local maximum.

Symbolic analysis of linear and nonlinear circuits utilizing digital computers

Abstract: Topological symbolic analysis of circuits defined by topological constraints, utilizing digital computers