Showing papers on "Equivalent circuit published in 1981"
TL;DR: In this paper, the authors considered solar cells as generators, and the classical one-diode equivalent circuit was assumed to be valid for a given light intensity, where the true circuit parameters R s, R sh, I s, and I ph were computed from the experimental data of the fourth-quadrant characteristics using a programmable calculator.
151 citations
TL;DR: In this article, a large-signal GaAs FET model is derived based on dc characteristics of the device and analytical expressions of modeled nonlinear elements are presented in a form convenient for circuit design.
Abstract: A large-signal GaAs FET model is derived based on dc characteristics of the device. Analytical expressions of modeled nonlinear elements are presented in a form convenient for circuit design. Power saturation and gain characteristics of a GaAs FET are studied theoretically and experimentally. An oscillator design employing the large-signal model is demonstrated.
136 citations
TL;DR: In this paper, an antenna consisting of an interconnected wire grid formed by etching metallic lines on a dielectric sheet backed by a metallic ground plane is described, and the theory of operation, analytical model, and experimental findings for this approach to a printed array are described.
Abstract: A description is given of an antenna consisting of an interconnected wire grid formed by etching metallic lines on a dielectric sheet backed by a metallic ground plane. The theory of operation, analytical model, and experimental findings for this approach to a printed array are described. The device is low cost, light weight, and has sufficient bandwidth to be of use in a variety of applications. An analytical model is developed which establishes transmission line equivalent circuits for the wire grid elements. Current distributions determined from the model are shown to predict accurately the measured pattern performance of a typical implementation. The bandwidth as established by various pattern parameters is quantitatively assessed. Particular emphasis is given to methods of amplitude control through control of line impedances. A particular design implementation is presented for a five-wavelength circular array with independent quadrant control. Measured results from this configuration are compared to theory.
120 citations
TL;DR: In this article, the basic electrical equivalent circuit of a laser diode is derived and the effects of spontaneous emission and self-pulsations are represented by a negative resistance in the model.
Abstract: The basic electrical equivalent circuit of a laser diode is derived. The effects of spontaneous emission and self-pulsations are included. It is found that self-pulsations are represented by a negative resistance in the model. Application of this model suggests purely electronic methods of suppressing relaxation oscillations in laser diodes.
118 citations
TL;DR: In this paper, a method for designing backfeed-type one-point fed circularly polarized antennas is described, where antennas are fed at one point from the back side of the substrate and have degeneracy resolving segments.
Abstract: This paper describes a method for designing backfeed-type one-point fed circularly polarized antennas. These antennas are fed at one point from the back side of the substrate and have degeneracy-resolving segments. Characteristics of the rectangular microstrip antennas with degeneracy-resolving segments are obtained by means of a variational method. The equivalent circuit at and near the resonance with perturbations is obtained and the condition for circularly polarized antennas is found from both theoretical and experimental viewpoints. Configurations and radiation characteristics of these antennas are discussed and it is shown that these antennas can be used as array elements.
111 citations
01 Oct 1981
TL;DR: In this article, a large-signal circuit model of a heterojunction injection laser is presented, which can be easily implemented on general-purpose nonlinear circuit analysis programs, and does not require specialised laser analysis software.
Abstract: A new large-signal circuit model of a heterojunction injection laser is presented. The model includes the current/voltage characteristics of the semiconductor heterojunction and the electro-optical dynamics of the active layer. It enables the laser and its electrical drive circuit to be analysed in a unified manner. The model can be easily implemented on general-purpose nonlinear circuit analysis programs, and does not require specialised laser analysis software. The model is illustrated with a number of simulated laser response characteristics.
104 citations
TL;DR: In this article, the results of an experimental investigation of the transient behavior of ground impedances were used to derive equivalent circuits and an analog model was constructed and satisfactory agreement with the theoretical analysis obtained.
Abstract: This paper presents the results of an experimental investigation of the transient behavior of ground impedances. The results obtained were used to derive equivalent circuits. An analog model was constructed and satisfactory agreement with the theoretical analysis obtained.
89 citations
TL;DR: In this article, an active circuit which behaves like a cold noise source is described, which uses a gallium arsenide FET and is given the name COLFET, and the appropriate theory is developed and practical circuits described using the circuit.
Abstract: An active circuit which behaves like a "cold" noise source is described. The circuit which uses a gallium arsenide FET is given the name COLFET. The appropriate theory is developed and practical circuits described using the circuit. Equivalent noise temperatures of less than 50 K have been measured for a 50-omega source at 1400 MHz.
85 citations
TL;DR: The special mechanism of the ionic conduction in the keratin layer is indicated as one of the causes for non-linearity in the current dependency of the skin impedance and in Lissajous figures.
Abstract: This paper describes the non-linear electrical properties of the skin during the passage of a sinusoidal current from the standpoint of the constant-current method. The non-linearity occurs in the current dependency of the skin impedance and in Lissajous figures. It exhibits both rapid and slow variations. The concept of a non-linear impedance and its equivalent circuit are introduced for a sinusoidal voltage. With regard to the current dependency of the impedance it can be said that both the starting point and the degree of the dependency vary with frequency and impedance. The nonlinearity is more apparent with a larger current, a lower frequency, and a higher impedance. with an increasing current, the ionic conductance increases and the polarisation admittance decreases. Lissajous figures are formed when the voltage is distorted notably from the sinusoidal wave form. Detailed investigations are undertaken for the elliptic figures, third harmonics, rectification, and breakdown of the skin appearing with a decrease of the frequency and increase of the current. Finally, the special mechanism of the ionic conduction in the keratin layer is indicated as one of the causes for non-linearity.
84 citations
TL;DR: In this paper, a novel technique for deriving direct and quadrature axis equivalent circuit models of turbogenerators from standstill frequency response measurements is proposed, which results in better representation of rotor body effects, particularly in the d-axis.
Abstract: A novel technique for deriving direct and quadrature axis equivalent circuit models of turbogenerators from standstill frequency response measurements is proposed. This technique differs from that proposed by previous investigators, and results in better representation of rotor body effects, particularly in the d-axis. This new method is applied to results of measurements on three large turbogenerators of similar rating but different rotor construction.
78 citations
TL;DR: In this article, the magnitude of the ratio correction factor (primary voltage divided by the product of turns ratio and secondary voltage) for frequencies up to 25 kHz for a wide range of burdens is calculated.
Abstract: Two standard, commercially available potential transformers designed for 60 Hz power applications are evaluated for use at frequencies of up to 10 kHz and voltages both above and below nominal rating. Using open and short-circuit impedance measurements, an equivalent circuit is developed that allows the calculation of the magnitude of the ratio correction factor (primary voltage divided by the product of turns ratio and secondary voltage) for frequencies up to 25 kHz for a wide range of burdens.
TL;DR: In this article, an automated testing procedure has been developed which obtains impedance data for the painted metal/solution interface over a wide range of frequencies using a Schlumberger frequency response analyser coupled to a computer via interfacing equipment.
TL;DR: A new current injected equivalent circuit approach (CIECA) to modeling switching dc-dc converter power stages is developed, which results in either a set of equations which completely describe input and out-put properties or an equivalent linear circuit model valid at small signal, low frequency levels.
Abstract: A new current injected equivalent circuit approach (CIECA) to modeling switching dc-dc converter power stages is developed, which starts with the current injected approach and results in either a set of equations which completely describe input and out-put properties or an equivalent linear circuit model valid at small signal, low frequency levels. This approach to modeling switching dc-dc converter power stages has the merits but not the demerits of both the electronic equivalent circuit state space average approach and the current injected control type approach, namely, 1) the modeling is very clear and is simple whether the converter operates in continuous or discontinuous inductor conduction modes, 2) the modeling results in an equivalent circuit which is very close to the actual converter, and 3) the equivalent circuit can be used directly in the computer for theoretical predictions like SPICE, etc.
TL;DR: In this article, the small-signal impedance-frequency response of electrochemical systems obeying the Nernst-Planck and Poisson equations is modelled with fixed-component transmission line equivalent circuits.
TL;DR: In this paper, a general methodology for the analysis of electrical grounding systems is presented, where the Earth is represented as a two layer semi-infinite region and an equivalent circuit model of the earth embedded electrodes and conductive soil is developed via numerical lution of Laplace equations.
Abstract: A general methodology for the analysis of electrical grounding systems is presented. Earth is represented as a two layer semiinfinite region. An equivalent circuit model of the earth embedded electrodes and conductive soil is developed via numerical lution of Laplace equations. The equivalent circuit model, together with the electric power system network, represents a large scale network which is solved via the modified nodal analysis method. The procedure enables accurate analysis of complicated grounding systems and computation of touch, step and transfer voltages. Effects of tower footing resistance, counterpoised wires, types of system faults (phase to ground, line to line, etc.) can be analyzed. Practical grounding systems can be easily analyzed because model reduction techniques can be incorporated in the analysis method. The methodology is demonstrated with the study of a nontrivial grounding system analysis problem.
TL;DR: An analytic Iarge-signal model for the GaAs FET is described which relates the terminal currents to the instantaneous terminal voltages and their time derivatives.
Abstract: An analytic Iarge-signal model for the GaAs FET is described which relates the terminal currents to the instantaneous terminal voltages and their time derivatives. It incorporates the device geometry and semiconductor parameters as well as the device parasitic circuit elements. The model is fast and efficient when implemented on a computer and is in a form suitable for large-signal circuit design and optimization.
TL;DR: A rigorous and general derivation of the modified nodal equations needed for a time, frequency and z -domain analysis of multiphase switched-capacitor networks is given and a general equivalent circuit is derived that allows to handle continuous coupling, piecewise-constant inputs as well as continuous inputs.
Abstract: A rigorous and general derivation of the modified nodal equations needed for a time, frequency and z -domain analysis of multiphase switched-capacitor networks is given. Also a general equivalent circuit for switched-capacitor networks is derived. This technique allows to handle continuous coupling, piecewise-constant inputs as well as continuous inputs. These results can be used to adapt existing circuit analysis programs, based on modified nodal analysis, for efficient simulation of switched-capacitor networks.
27 May 1981
TL;DR: The traditional stacked crystal filter (SCF) as mentioned in this paper is composed of two bonded piezoelectric plates with a common ground plane at the bond line, and the filter input and output terminals are largely isolated by the ground plane electrode to provide a high degree of off resonance rejection.
Abstract: The traditional stacked crystal filter (SCF) is composed of two bonded piezoelectric plates with a common ground plane at the bond line. Thus, the filter input and output terminals are largely isolated by the ground plane electrode to provide a high degree of off resonance rejection. In operation, the system is driven to resonance by the input resonator (transducer) and the resulting energy is radiated to the output plate which acts as a receive transducer to couple the energy to the external electrical circuit.
Proceedings Article•
01 Sep 1981TL;DR: In this article, a table look-up MOSFET model for circuit simulation program is presented. But the model is not suitable for circuit simulations with high computational complexity and short computation time.
Abstract: MOSFET models for circuit simulation program are generally required to have a good accuracy and short computation time. The authors have developed a novel table look-up MOSFET model which meets both requirements.
TL;DR: The paper presents the general theory of automatic gain control (a.g.c).
Abstract: The paper presents the general theory of automatic gain control (a.g.c). It includes discussions on loop gain, regulation and the relation between loop parameters and output level stability. An equivalent circuit is derived which is used in the study of dynamic behaviour. The work is extended to cover sampled data a.g.c. systems and design guidelines are derived for a variety of situations.
TL;DR: In this article, a thyristor controlled quadrature voltage injection transformer is used to improve the transient stability performance of a generator connected, through a transmission circuit, to a power-system.
Abstract: A thyristor controlled quadrature voltage injection transformer is used to improve the transient stability performance of a generator connected, through a transmission circuit, to a power-system. The paper discusses the effect of alternative control strategies and shows that not only can first swing maximum angle be reduced, but the subsequent transients can be damped.
IBM1
TL;DR: In this article, broadband equivalent circuits for straight-wire and wire-loop structures are developed, and the realizability of the circuits is explored in terms of the positive real (PR) function properties of the circuit admittances.
Abstract: Some realizable broad-band equivalent circuits for straight-wire and wire-loop structures are developed. The realizability of the circuits is explored in terms of the positive-real (PR) function properties of the circuit admittances. The postulate of PR "terminal eigenadmittances" as couched by Pearson and Wilton [8] is generally supported in the numerical examples, but a potential counterexample-that of the quarter-driven wire-occurs as well. A "dominant pole-pair" approach leads to a quate satisfactory approximate synthesis for the structures studied here. The conduct of this approximate synthesis is described in the context of the Bott-Duffin synthesis procedure. The circuits developed are tested by comparing their computed transient response with the response of electrodynamic models for the same structures.
TL;DR: In this paper, given a linear network of capacitors, periodically controlled switches and sources, the authors derive the adjoint network and show how it can be used to reduce the computational complexity of the frequency, noise and sensitivity analysis.
Abstract: Given a linear network of capacitors, periodically controlled switches and sources we derive its adjoint network and show how it can be used to reduce the computational complexity of the frequency, noise and sensitivity analysis.
The construction of the adjoint switched capacitor circuit turns out to be quite simple, even for switched capacitor networks with more than two phases or with a continuous input-output path. Moreover this construction can be performed equivalently in the time domain or on the equivalent circuit.
In order to facilitate the implementation in a computer-aided-design program all derivations are performed in the modified nodal analysis formulation (MNA).
TL;DR: Sense-amplifier column and cell alpha particle hits have been simulated for a 64K MOS dynamic RAM using SPICE, a circuit simulation program, and the column to sense amplifier impedance is found to strongly influence the likelihood of soft errors.
Abstract: Sense-amplifier column and cell alpha particle hits have been simulated for a 64K MOS dynamic RAM using SPICE, a circuit simulation program. Simulations investigate the influence of circuit, timing, and layout on the possibility of alpha soft errors. The column to sense amplifier impedance is found to strongly influence the likelihood of soft errors. Results are useful for designing for alpha immunity.
TL;DR: Kuroda's identities, which are used in analysis and synthesis of distributed transmision line circuits, may be applied to mixed lumped and distributed circuits and it is shown that circuits consisting of cascade connections of lumped reactances and uniform transmission lines are equivalent.
Abstract: Kuroda's identities, which are used in analysis and synthesis of distributed transmision line circuits, may be applied to mixed lumped and distributed circuits. It is shown that circuits consisting of cascade connections of lumped reactances and uniform transmission lines are equivalent to circuits consisting of a cascade connection of nonuniform transmission lines, lumped reactances, and ideal transformers. Moreover, by using these equivalent transformations, network functions of some nonuniform transmisssion lines can be derived exactly.
TL;DR: In this article, the tradeoffs between performance and bandwidth, and the important design criteria, particularly with respect to the layout of monolithic inductors, are investigated, and a simple equivalent circuit model is presented.
Abstract: Several designs of monolithic switches for X-band applications have been fabricated and tested. These switches, which consist of two parallel-resonated GaAs FET's in a series SPDT configuration, have very low dc power dissipation, low insertion loss, and are bidirectional. An insertion loss of 0.7 dB with 28-dB isolation at 10.2 GHz has been measured for these devices. A simple equivalent circuit model is presented which explains reasonably well the basic features of resonated GaAs FET switches. The tradeoffs between performance and bandwidth, and the important design criteria, particularly with respect to the layout of monolithic inductors, are investigated.
Book•
01 Jan 1981
TL;DR: This chapter discusses circuit analysis techniques used in computer-Aided Circuit Analysis, as well as basic Elements and Laws, and the Laplace Transforms, which transformed the circuits into two-Port networks.
Abstract: 1: Basic Elements and Laws. 2: Circuit Analysis Techniques. 3: Important Circuit Concepts. 4: Energy-Storage Elements. 5: First-Order Circuits. 6: Second-Order Circuits. 7: Computer-Aided Circuit Analysis. 8: Sinusoidal Analysis. 9: Power. 10: Important AC Concepts. 11: The Laplace Transforms. 12: Two-Port Networks. 13: Fourier Series. Appendices:. A. Matrices and Determinants. B. SPICE
TL;DR: In this article, a simple equivalent circuit for a commonly encountered radial-line/coaxial-line junction was presented for the case where the dominant modes in the respective lines are the only propagating modes.
Abstract: A simple equivalent circuit is presented for a commonly encountered radial-line/coaxial-line junction. The equivalent circuit is applicable to the usual situation where the dominant modes in the respective lines are the only propagating modes.