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Showing papers on "Equivalent circuit published in 1983"


Journal ArticleDOI
TL;DR: The driven-right-leg circuit is analyzed and it is shown that high loop gains can cause instability and equations that can be used to design circuits that minimize common mode voltage without instability are presented.
Abstract: The driven-right-leg circuit is often used with biopotential differential amplifiers to reduce common mode voltage. We analyze this circuit and show that high loop gains can cause instability. We present equations that can be used to design circuits that minimize common mode voltage without instability. We also show that it is important to consider the reduction of high-frequency interference from fluorescent lights when determining the bandwidth of the drivenright-leg circuit.

417 citations


Journal ArticleDOI
TL;DR: In this paper, the a−c conductivity of a polycrystalline Li+ ion conducting solid electrolyte, LISICON, has been measured over the frequency range 10−3−107 Hz and attention focused on the methods of data analysis.
Abstract: The a‐c conductivity of a polycrystalline, Li+ ion conducting solid electrolyte, LISICON, , has been measured over the frequency range 10−3–107 Hz and attention focused on the methods of data analysis. The data show intragranular (bulk) and grain boundary effects in which, for a given sample, both effects are characterized by a similar activation energy; a constriction resistance model for the latter is proposed based on air gaps existing in polycrystalline sinters of less than theoretical density. The data only crudely fit a Debye‐like equivalent circuit, composed of frequency independent resistors and capacitors, but fit well an equivalent circuit that contains Jonscher elements, i.e., frequency dependent admittances, in addition to normal and elements. Two such Jonscher elements are needed, one for the grain boundary and one for the intragranular contribution. With this circuit, departures from ideality in, e.g., the cpmplex impedance, admittance, and electric modulus planes are accounted for.

271 citations


Journal ArticleDOI
TL;DR: The general form of the plane-wave transmission/frequency curves for frequency-selective surfaces consisting of arrays of double squares has been deduced from the performance of 13 different arrays as discussed by the authors.
Abstract: The general form of the plane-wave transmission/frequency curves for frequency-selective surfaces consisting of arrays of double squares has been deduced from the performance of 13 different arrays. Band spacing ratios between 1.5 and about 2.2 are available. An equivalent circuit is presented for design work.

220 citations


DOI
01 Jan 1983

193 citations


Journal ArticleDOI
01 Jan 1983
TL;DR: In this article, an equivalent circuit model of a linear induction motor is developed, using the rotary-motor model as a basis, which is modified to account for the so-called ''end effect´ and is used to predict output thrust, vertical forces and couples.
Abstract: An equivalent-circuit model of a linear induction motor is developed, using the rotary-motor model as a basis. The rotary-motor model is modified to account for the so-called `end effect´ and is used to predict output thrust, vertical forces and couples. These predictions are checked against test results of a practical motor used on a prototype transit vehicle.

190 citations


01 Dec 1983
TL;DR: This thesis presents a new method of analyzing MOS circuit delay, based on a single-time-constant approximation, which can be modelled by the output of a circuit consisting of a single MOS transistor and a single capacitor.
Abstract: Performance is an important aspect of integrated circuit design, and depends in part on the speed of the underlying circuits. This thesis presents a new method of analyzing MOS circuit delay, based on a single-time-constant approximation. The timing models characterize the circuit by a single parameter, which depends on the resistance and capacitance of the circuit elements. To ensure the single- time-constant approximation is valid for a particular circuit, the timing models provide both an estimate and bounds for the output waveform. For circuits where the bounds are poor, an improved timing model is derived. These simple models provide insight about circuit performance issues, as well as determining the circuit delay. The timing models are first developed for linear networks and then are extended to model MOS circuits driven by a step input. By using the single-time-constant approximation, the output waveform of a complex MOS circuit can be modelled by the output of a circuit consisting of a single MOS transistor and a single capacitor. Finally, a new circuit model of a gate is used to derive the output waveform of a circuit driven by an arbitrary input. The resulting timing model does not depend strongly on the shape of the input: the output waveform only depends on the input''s slope at the gate''s switching voltage.

155 citations


Journal ArticleDOI
TL;DR: In this article, a detailed circuit representation of a six phase synchronous machine with mutual leakage couplings between the two sets of three phase stator windings is described, and the main modes of power transfer of a 6 phase machine with sinusoidal inputs are examined.
Abstract: This paper describes a detailed circuit representation of a six phase synchronous machine wherein mutual leakage couplings between the two sets of three phase stator windings are included. The main modes of power transfer of a six phase machine with sinusoidal inputs are examined. A harmonic phasor method of steady-state analysis to obtain the current, voltage and torque waveforms of a six phase machine with mixed AC-DC stator connections is described. It is shown that the output waveforms for various operating conditions from a digital computer program using the harmonic phasor method agree remarkably well with those obtained from an established detailed analog simulation.

128 citations


Journal ArticleDOI
TL;DR: In this paper, small-signal two-port circuit models of packaged broad-stripe and buried-heterojunction AlGaAs laser diodes are presented based on the single-mode rate equations, and include the heterojunction I-V and space-charge characteristics.
Abstract: Small-signal two-port circuit models of packaged commerical broad-stripe and buried-heterojunction AlGaAs laser diodes are presented. The models are based on the single-mode rate equations, and include the heterojunction I-V and space-charge characteristics. Also included are package and substrate parasitic. The models agree well with measured reflection coefficient and modulation frequency response data, and can be incorporated in standard microwave circuit analysis programs.

124 citations


Journal ArticleDOI
TL;DR: In this article, a comprehensive study of single-gate GaAs FET frequency doublers is presented, with special emphasis on exploring high-frequency limitations, while yielding explanations for previously observed lower frequency phenomena as well.
Abstract: A comprehensive study of single-gate GaAs FET frequency doublers is presented. Special emphasis is placed on exploring high-frequency limitations, while yielding explanations for previously observed lower frequency phenomena as well. Extensive Iarge-signal simulations demonstrate the underlying relationships between circuit performance characteristics and principal design parameter. Verifying experiments include straight frequency doubler and a self-oscillating doubler, both with output signal frequencies in Ku-band. The self-oscillating doubler appears especially attractive, yielding an overall dc-to-RF efficiency of 10 percent. The type of transistor employed in the numerical and experimental examples possesses a gate length of 0.5 µm and a gate width of 250 µm.

93 citations


Journal ArticleDOI
TL;DR: The techniques used in relaxation-based electrical simulation are presented in a rigorous and unified framework, and the numerical properties of the various methods are explored.
Abstract: Circuit simulation programs have proven to be most important computer-aided design tools for the analysis of the electrical performance of integrated circuits. One of the most common analyses performed by circuit simulators and the most expensive in terms of computer time is nonlinear time-domain transient analysis. Conventional circuit simulators were designed initially for the cost-effective analysis of circuits containing a few hundred transistors or less. Because of the need to verify the performance of larger circuits, many users have successfully simulated circuits containing thousands of transistors despite the cost. Recently, a new class of algorithms has been applied to the electrical IC simulation problem. New simulators using these methods provide accurate waveform information with up to two orders of magnitude speed improvement for large circuits. These programs use relaxation methods for the solution of the set of ordinary differential equations, which describe the circuit under analysis, rather than the direct sparse-matrix methods on which standard circuit simulators are based. In this paper, the techniques used in relaxation-based electrical simulation are presented in a rigorous and unified framework, and the numerical properties of the various methods are explored. Both the advantages and the limitations of these techniques for the analysis of large IC's are described.

82 citations


Journal ArticleDOI
01 Aug 1983
TL;DR: In this article, the principles involved in switched-capacitor circuit operation are examined with emphasis on physical insight rather than mathematical abstraction, albeit without sacrificing rigor, generality, and accuracy.
Abstract: The principles involved in switched-capacitor circuit operation are examined with emphasis on physical insight rather than mathematical abstraction, albeit without sacrificing rigor, generality, and accuracy. Detailed time waveforms are extensively used. Input-output difference equations are discussed. After a complete time domain description, it is shown that a frequency-domain description becomes trivial through the use of phasors; z-transforms are avoided. Equivalent systems are derived. Analysis techniques are developed in parallel with the investigation of circuit properties.

Journal ArticleDOI
TL;DR: Techniques for analyzing the signal transmission properties of long resistive interconnects on integrated circuits are presented and guidance is provided for selecting the number of elements needed to accurately simulate performance under various conditions.
Abstract: Techniques for analyzing the signal transmission properties of long resistive interconnects on integrated circuits are presented. Because accurate measurements of propagation characteristics on chip are difficult to make, RC transmission line theory is used to establish exact performance. The results of various simulations are compared to this theoretical performance. Guidance is provided for selecting the number of elements needed to accurately simulate performance under various conditions.

Journal ArticleDOI
TL;DR: The basic philosophy and the general structure of a user-oriented program package capable of designing broad classes of nonlinear microwave subsystems are described and the application to a practical medium-power oscillator shows that the program is numerically efficient and yields well-defined and accurate results.
Abstract: The paper describes the basic philosophy and the general structure of a user-oriented program package capable of designing broad classes of nonlinear microwave subsystems. Some of the peculiar aspects of the nonlinear design problem and the computer solutions adopted are discussed in detail. The application to a practical medium-power oscillator shows that the program is numerically efficient and yields well-defined and accurate results. Furthermore it provides full coverage of several aspects of circuit performance that were previously treated by empirical approaches, such as detailed effects of higher harmonics, active device operating temperatures, and circuit regulations.

Journal ArticleDOI
TL;DR: A prototype circuit simulator, based on a revised formulation of the circuit equations, is described, which is oriented towards the simulation of digital MOS circuits and takes advantage of the special form of such circuits.
Abstract: A prototype circuit simulator, based on a revised formulation of the circuit equations, is described. The formulation is based on functional models of active elements, which can be derived from either equivalent-circuit or black-box models. The implementation is oriented towards the simulation of digital MOS circuits and takes advantage of the special form of such circuits. Some of the implementation issues are discussed, particularly the hierarchical structuring of the circuit equations and the use of splines to facilitate macromodeling; continuation methods for computing transfer curves are also discussed. Finally, the results of computational experiments are presented.

Journal ArticleDOI
TL;DR: In this article, a method for determining the steady state response of nonlinear microwave circuits with periodic excitation is proposed, which minimizes time-domain calculations by introducing a criterion for selecting the variables to be considered as unknowns and for solving the resulting nonlinear system by a new and efficient algorithm.
Abstract: A new method for determining the steady-state response of nonlinear microwave circuits with periodic excitation is proposed. The method minimizes time-domain calculations by introducing a criterion for selecting the variables to be considered as unknowns and for solving the resulting nonlinear system by a new and efficient algorithm. It has exhibited the capability for handling a large number of harmonics and nonlinearities. To illustrate the generality and usefulness of the method, a pumped diode and a MESFET frequency doubler are analyzed.

Journal ArticleDOI
TL;DR: In this paper, three methods of measuring ZA were devised and used in measuring three impedance levels of microstrip, which were consistent with the power-current characteristic impedance definition of the approximate longitudinal-section electric (LSE) model of nricrostrip.
Abstract: Voltage and current cannot be defined uniquely for microstrip except at zero frequency, and therefore microstrip has not been rigorously incorporated into circuit theory. However, in engineering practice, micro-strip exhibits an apparent characteristic impedance, denoted here by ZA, that can be measured. Three methods of measuring ZA were devised and used in measuring three impedance levels of microstrip. These methods are described and experimental results presented. The measurements of ZA were found to be consistent with the power-current characteristic impedance definition of the approximate longitudinal-section electric (LSE) model of nricrostrip. Simple approximate formulas for representing ZA are also discussed.

Journal ArticleDOI
A. S. Morched1, V. Brandwajn1
TL;DR: In this article, a method to generate network equivalents from the frequency response of its admittance has been developed, which are in the form of lumped parameter circuits, have a simple structure and reproduce the network's behaviour over a wide frequency range.
Abstract: In electromagnetic transients studies, only a limited part of a transmission system can be modelled in detail. The remaining parts of the system have to be reduced to equivalents. Simple equivalents which reproduce the network's response at few frequency points can introduce significant errors into the calculated transients. A method to generate network equivalents from the frequency response of its admittance has been developed. The equivalents are in the form of lumped parameter circuits, have a simple structure and reproduce the network's behaviour over a wide frequency range. The developed method was used to generate an equivalent for a sample system. Voltage transients due to an energization of a transmission line from that sample system were calculated. The results of calculations with the full system representation and the developed equivalent showed a good agreement.

Journal ArticleDOI
TL;DR: In this article, a numerical modeling technique is described which allows the accurate large-signal characterization of highly doped (>1023m-3) GaAs MESFET's.
Abstract: A numerical modeling technique is described which allows the accurate large-signal characterization of highly doped (>1023m-3) GaAs MESFET's. A rigourous two-dimensional numerical analysis is used to extract the FET terminal currents. Specially formulated finite difference equations are used to produce stable, accurate, and efficient solutions. By embedding the device in a simple circuit model, a two, terminal time domain response is obtained which is Fourier analyzed to produce a "device surface". The technique is applied to the analysis and design of a Ku -band monolithic microwave Oscillator, using a 0.5-µm gate length MESFET. A simple equivalent circuit model is proposed which predicts an output of 4 dBm at 16.2 GHz for this oscillator.

Journal ArticleDOI
TL;DR: The techniques used in relaxation-based electrical simulation are presented in a rigorous and unified framework, and the numerical properties of the various methods are explored.
Abstract: Circuit simulation programs have proven to be most important computer-aided design tools for the analysis of the electrical performance of integrated circuits. One of the most common analyses performed by circuit simulators and the most expensive in terms of computer time is nonlinear time-domain transient analysis. Conventional circuit simulators were designed initially for the cost-effective analysis of circuits containing a few hundred transistors or less. Because of the need to verify the performance of larger circuits, many users have successfully simulated circuits containing thousands of transistors despite the cost.Recently, a new class of algorithms has been applied to the electrical IC simulation problem. New simulators using these methods provide accurate waveform information with up to two orders of magnitude speed improvement for large circuits. These programs use relaxation methods for the solution of the set of ordinary differential equations, which describe the circuit under analysis, rather than the direct sparse-matrix methods on which standard circuit simulators are based.In this paper, the techniques used in relaxation-based electrical simulation are presented in a rigorous and unified framework, and the numerical properties of the various methods are explored. Both the advantages and the limitations of these techniques for the analysis of large IC's are described.

Journal ArticleDOI
TL;DR: In this paper, the electrical series resistance of an IMPATT diode was measured based on the oscillation threshold bias current of the diode in a standard circuit and applied to GaAs diodes near 40 GHz.
Abstract: A new method is given for determining the electrical series resistance of an IMPATT diode. The measurement is based on observation of the oscillation threshold bias current for a diode in a standard circuit. The method is applied to GaAs diodes near 40 GHz. The values obtained are used to quantitatively explain other performance characteristics of the diodes.

Proceedings ArticleDOI
01 Jan 1983
TL;DR: In this paper, an equivalent circuit model for a spurline filter section in an inhomogeneous coupled-line medium whose even and odd mode phase velocities are unequal is presented.
Abstract: This paper provides a new equivalent circuit model for a spurline filter section in an inhomogeneous coupled-line medium whose even and odd mode phase velocities are unequal. This equivalent circuit permits the exact filter synthesis to be performed easily. Millimeter-wave filters at 26 to 40 GHz and 75 to 110 GHz have been fabricated using the model, and experimental results are included which validate the equivalent circuit model.

Proceedings ArticleDOI
01 Aug 1983
TL;DR: In this paper, the authors developed an optimal RFI model that uses a RFI in a GSM/GPRS mode power source and matching the model with a matching CFI.
Abstract: As a s t e p toward d e s ig n in g a f am ily o f power l i n e i n t e r f e r e n c e f i l t e r s d e d i c a t e d f o r o f f l i n e sw i t c h in g mode power s u p p l i e s , an e q u i v a l e n t c i r ­ c u i t was developed t o d e s c r i b e t h e t y p i c a l c h a r ­ a c t e r i s t i c s of t h e n o i s e source e x i s t i n g a t th e AC t e r m i n a l s of t h e s e s u p p l i e s . The model uses l i n e a r e l em en ts t o p r e d i c t t o a f i r s t o rd e r th e behav io r o f RFI f i l t e r s as a p p l i e d t o sw i t c h in g mode power s u p p l i e s . C o n s o l i d a t i n g b a s i c f i l t e r and matching c i r c u i t a n a l y s i s with t h e e q u i v a l e n t n o i s e s ou rce c i r c u i t f a c i l i t a t e s t h e development o f an optimum RFI f i l t e r f o r sw i t ch in g mode power s u p p l i e s .

Journal ArticleDOI
TL;DR: In this paper, the surface photovoltage measured capacitance (SPMC) method was proposed to measure the surface potential barrier induced by low intensity chopped light whose photon energy exceeds the band gap energy.
Abstract: Surface photovoltage measured capacitance (SPMC), a novel technique for determining the properties of semiconducting materials, is introduced. SPMC permits the determination of a semiconductor depletion layer capacitance by measuring changes of the surface potential barrier induced by low intensity chopped light whose photon energy exceeds the band‐gap energy. The theory of the SPMC technique is derived, and an equivalent circuit for analyzing the measurements is described. The present technique is compared with the conventional current measured capacitance method, and it is shown that using SPMC the separation of the depletion layer capacitance from the influence of the surface states can be performed by measurements at only one frequency of light modulation. This is a simpler procedure than the frequency dispersion measurement required of conventional capacitance techniques. Measurements of the capacitance‐voltage characteristics of a semiconductor/electrolyte system, in particular n‐type WS2 exposed to...

Journal ArticleDOI
TL;DR: In this article, a method of obtaining synchronous machine d and q axis impedances by test as function of frequency of d, q components is presented, which involves running the machine at reduced speeds, with a line-to-line short circuit between phases, and temporarily applying excitation to produce line to line short circuit current at fundamental frequency corresponding to the particular running speed.
Abstract: A method of obtaining synchronous machine d and q axis impedances by test as function of frequency of d, q components is presented. The test involves running the machine at reduced speeds, with a line-to-line short circuit between phases, and temporarily applying excitation to produce line-to-line short circuit current at fundamental frequency corresponding to the particular running speed. Records of line-to-line voltages and short circuit current, along with measurement of rotor angle, are processed to yield d and q components of voltages, currents and flux linkages which turn out to be periodic functions of the fundamental frequency plus harmonics. Straight forward Fourier analysis yields the complex values of operational inductances or impedances L d (j2?), L q (j2?), Z d (j2?) or Z g (j2?) where ?is equal to the speed of the machine at which the tests are conducted.

Journal ArticleDOI
TL;DR: In this article, an equivalent circuit of an open-ended coaxial line used as a sensor for dielectric measurements is proposed, and the parameters of the circuit are found by least square fitting to the values for the total capacitance calculated numerically.
Abstract: An equivalent circuit of an open-ended coaxial line used as a sensor for dielectric measurements is proposed. The parameters of the circuit are found by least square fitting to the values for the total capacitance calculated numerically.

Proceedings ArticleDOI
06 Jun 1983
TL;DR: In this paper, the authors present analytical results, design considerations and experimental results at 1.5 MHZ, for a novel, resonant, high-frequency de/de converter.
Abstract: We present analytical results, design considerations and experimental results at 1.5 MHZ, for a novel, resonant, high-frequency de/de converter. The circuit works virtually without dynamic losses at several-MHz switching frequency. The analysis gives the permissible area of the equivalent load impedance for lossless operation, presents a model for regulation by narrow-band frequency control, and characterizes the output full-wave rectifier. Experimental data from a 1.5-MHz, 40-W converter verify the results of the theoretical analysis. The measured efficiency was 85%.

Patent
Arman V. Dolikian1
06 Jul 1983
TL;DR: In this paper, the first input to a comparator circuit receives the input signal to the limiter circuit, and different voltages from the voltage divider network (18) are applied to the second input to create a dynamic hysteresis effect in the comparator circuits.
Abstract: Limiter circuit (13) with dynamic hysteresis for providing improved distortion immunity at the circuit output is response to an input signal. The limiter circuit (13) includes a positive (15) and negative peak detector (17). Two weighted averages are taken of the positive and negative peaks, preferably by means of a voltage divider network (18). The first input to a comparator circuit receives the input signal to the limiter circuit (13). Different voltages from the voltage divider network (18) are applied to the second input of the comparator circuit (21) so as to create a dynamic hysteresis effect in the comparator circuit (21). The different voltages are chosen in response to the output voltage from the comparator circuit (21) by means of an analog switch (19). The comparator circuit (21) includes a fixed hysteresis voltage for stabilizing the limiter circuit (13) at low level voltage input signals.

Journal ArticleDOI
TL;DR: Using a second-order circuit model, the complex dynamical behavior of a typical Josephson-junction circuit is rigorously analyzed using integral manifolds in this article, where it is shown that the non-autonomous circuit has a stable integral manifold.
Abstract: Using a second-order circuit model the complex dynamical behavior of a typical Josephson-junction circuit is rigorously analyzed using integral manifolds The key idea is to prove that under certain small-parameter assumptions, the nonautonomous circuit has a stable integral manifold Moreover, this manifold is doubly periodic so that steadystate behavior of the Josephson-junction circuit reduces to the analysis of its dynamics on a torus Well-known experimental phenomena, such as the existence of hysteresis in the dc Josephson circuit and voltage steps in the ac Josephson circuit, are rigorously derived and explained

Patent
09 Mar 1983
TL;DR: In this paper, the authors proposed a pulse-width modulation circuit in which an output from a latch circuit (136) for holding a count obtained by counting a reference clock signal in accordance with the period of a signal to be modulated is compared by a comparator (152) with a ramp counter (153) for counting the signal at a predetermined period so as to perform a pulsewidth modulation.
Abstract: The invention provides a pulse-width modulation circuit in which an output from a latch circuit (136) for holding a count obtained by counting a reference clock signal in accordance with the period of a signal to be modulated is compared by a comparator (152) with an output from a ramp counter (153) for counting the reference clock signal at a predetermined period so as to perform a pulse-width modulation The number of bits of the comparator (152) and the ramp counter (153) is decreased by n bits with respect to the number N (N > n) of bits of the latch circuit (136)

Journal ArticleDOI
TL;DR: In this article, a numerical procedure is described to calculate the parameters of the equivalent circuit of a solar cell, based on the application of algorithms to optimise nonlinear functions defining the difference between experimental characteristics and the theoretical model.
Abstract: A numerical procedure is described to calculate the parameters of the equivalent circuit of a solar cell, based on the application of algorithms to optimise nonlinear functions defining the difference between experimental characteristics and the theoretical model The authors have obtained empirical data from dark I(V) characteristics A study of the method to obtain the initial solution is also included Results obtained for space solar cells and commercial cells (terrestrial use) are given Modifications of the commonly used equivalent circuit model of solar cells are suggested