Showing papers on "Equivalent series resistance published in 1979"
TL;DR: In this article, the optimal value of the minimum noise figure F o of GaAs MESFET's is expressed in terms of either representative equivalent circuit elements or geometrical and material parameters in simple analytical forms.
Abstract: The optimal value of the minimum noise figure F o of GaAs MESFET's is expressed in terms of either representative equivalent circuit elements or geometrical and material parameters in simple analytical forms. These expressions are derived on a semiempirical basis. The predicted values of F o for sample GaAs MESFET's using these expressions are in good agreement with the measured values at microwave frequencies. The expressions are then applied to show design optimization for low-noise devices. This exercise indicates that shortening the gate length and minimizing the parasitic gate and source resistances are essential to lower F o . Moreover, a simple shortening of the gate length may not bring an improved F o unless the unit gate width is accordingly narrowed. The maximum value of the unit gate width is defined as the width above which the gate metallization resistance becomes greater than the source series resistance. Short-gate GaAs MESFET's with optimized designs promise a superior noise performance at microwave frequencies through K band. The predicted values of F o at 20 GHz, for example, for a half-micrometer gate device and a quarter-micrometer gate device are 3 and 2 dB, respectively. These devices could be fabricated with the current technology.
308 citations
TL;DR: A new "distributed model" of an epithelium is developed to take account of these structures and thereby obtain much better fits to the data, showing that the commonly used equivalent circuit models of epithelia give significant misfits to the impedance data.
121 citations
TL;DR: In this article, the authors derived the optimum doping profile of a lightly doped layer that introduces the minimum series resistance and sustains a given junction breakdown voltage, which applies to a one-dimensional Schottky diode and qualitatively to the collector or drain doping profiles of transistors.
Abstract: The optimum doping profile of a lightly doped layer that introduces the minimum series resistance and sustains a given junction breakdown voltage is derived. The theory applies to a one-dimensional Schottky diode and qualitatively to the collector or drain doping profiles of transistors. The minimum series resistance is found to be about 3.7 × 10-9 V\min{B}\max{2.6} Ω.cm2for an n silicon layer. The optimum doping profile can be closely approximated by a conventional uniformly doped n-n+structure.
118 citations
TL;DR: A simple method for obtaining the series resistance of solar cells is described and Universal current-voltage characteristics of the solar cells are given to illustrate the effects of series and shunt resistance.
Abstract: Series resistance is an important parameter in solar cell design and fabrication. Methods reported in literature for its determination are not suitable for routine use. We describe a simple method for obtaining the series resistance. Universal current-voltage characteristics of the solar cells are also given to illustrate the effects of series and shunt resistance. We also offer an explanation for the often observed drop in efficiency when small area cells are scaled upward. Cells less than 0.25 cm2 represent the intrinsic potential of any given structure or diode but do not reflect series resistance effects that must be eliminated with larger area cells and the practical problems of griding to allow for current collection.
105 citations
TL;DR: In this article, the variation of Q and capacitance slope for series-and shunt-connected interdigital capacitors is shown and a theory suitable for interactive design of capacitors was given.
Abstract: The variation of Q and capacitance slope for series- and shunt-connected interdigital capacitors is shown. A theory suitable for interactive design of capacitors is given.
57 citations
01 May 1979
TL;DR: Using a second generation current conveyor (CC II), a new resonator network containing a resistance (R)-capacitance (C)-frequency dependent negative resistance (D) series configuration is proposed in this paper.
Abstract: Using a second generation current conveyor (CC II), a new resonator network containing a resistance (R)-capacitance (C)-frequency dependent negative resistance (D) series configuration is proposed. The network is canonic and both the equal-valued capacitors are grounded. ω 0 and Q of the resonator have been shown to be practically insensitive to changes in active parameters.
12 citations
01 Jun 1979
TL;DR: In this article, a user-oriented computer program for analyzing microwave and millimeter wave mixers with a single Schottky barrier diode of known I-V and C-V characteristics is described.
Abstract: A user oriented computer program for analyzing microwave and millimeter wave mixers with a single Schottky barrier diode of known I-V and C-V characteristics is described. The program first performs a nonlinear analysis to determine the diode conductance and capacitance waveforms produced by the local oscillator. A small signal linear analysis is then used to find the conversion loss, port impedances, and input noise temperature of the mixer. Thermal noise from the series resistance of the diode and shot noise from the periodically pumped current in the diode conductance are considered. The effects of the series inductance and diode capacitance on the performance of some simple mixer circuits using a conventional Schottky diode, a Schottky diode in which there is no capacitance variation, and a Mott diode are studied. It is shown that the parametric effects of the voltage dependent capacitance of a conventional Schottky diode may be either detrimental or beneficial depending on the diode and circuit parameters.
12 citations
TL;DR: In this paper, a beam lead GaAs Schottky-barrier mixer diode with high performance has been developed for use in super high frequency (SHF) receiving system.
Abstract: A novel beam lead GaAs Schottky-barrier mixer diode with high performance has been developed for use in super high frequency (SHF) receiving system. The parasitic capacitance of the diode has been reduced to 0.03 pF by using thick polyimide insulating film formed by improved etching techniques. The series resistance has been lowered to 0.5 Ω by a liquid-phase double epitaxial method of growing an n-n++active layer on an n+wafer. The total diode capacitance at zero bias has been lowered to 0.15 pF using a 10-µm junction diameter. An n factor of less than 1.10 was obtained. The calculated cutoff frequency including parasitic capacitance exceeds 2000 GHz. Several reliability tests including temperature cycling in high humidity show good results. In an SHF downconverter consisting of a waveguide which contains a planar circuit, the diode was attached to the planar circuit by means of an intermediate plate, despite the small diode dimensions of 0.75 mm by 0.22 mm. An overall noise figure (NF) as low as 4.3 dB, and conversion loss as low as 3.0 dB were achieved at 12 GHz (IF range of 290-470 MHz and IF amplifier NF of 1.5 dB). These values are shown to be satisfactory for application to a low-noise receiving system for satellite TV broadcasting.
11 citations
TL;DR: In this article, two new schemes for grounded-inductor simulation with single grounded capacitors using the second-generation current conveyors (c.c. II) are reported.
Abstract: Two new schemes for grounded-inductor simulation with single grounded capacitors using the second-generation current conveyors (c.c. II) are reported. The realised inductors L and their quality factors Q can be independently adjusted and hence are suitable for high-quality applications. L and Q are shown to be quite stable and are practically insensitive to the changes in the active c.c. II parameters.
10 citations
TL;DR: In this paper, the Schottky barrier in the Si at the Si/glass interface in series with the resistance of the bulk V2O5 glass was investigated and the series resistance was found to be voltage, temperature, and illumination intensity dependent.
Abstract: The dark and illuminated characteristics of SnO2/V2O5 : P2O5/Si heterojunctions can be explained by considering the cell to consist of a Schottky barrier in the Si at the Si/glass interface in series with the resistance of the bulk V2O5 : P2O5 glass. The series resistance is voltage, temperature, and illumination‐intensity dependent. Space‐charge‐limited currents are found to be an unimportant conduction mechanism. The resistance of the amorphous glass layer precludes the use of these cells as practical solar‐energy converters.
8 citations
TL;DR: In this paper, a circuit configuration to simulate large on-chip capacitors and inductors is discussed, based on the backward-Euler integration rule and can be realized by means of a sample-and-hold function.
Abstract: A circuit configuration to simulate large on-chip capacitors and inductors is discussed. It is based on the backward-Euler integration rule and can be realized by means of a sample-and-hold function. It leads to filters with time constants determined by resistor ratios and by the sample frequency.
TL;DR: In this paper, the properties of TaN Ta2O5Nx Al capacitors formed by the anodization of sputtered TaN films were investigated and the changes in capacitance, dielectric loss, temperature coefficient of capacitance and leakage currents were studied for samples containing different concentrations of nitrogen.
TL;DR: In this paper, the series resistance of Zn-doped p−Ga0.3Al0.7As was measured experimentally and it was found that the resistivity of Z−doped P−Ga 0.3As is about 10 times higher than that of the Zn−diffused p-GaAs layer.
Abstract: Series resistance of Zn‐doped p‐ (GaAl)As/p‐GaAs/n‐GaAs solar cells fabricated by liquid‐phase epitaxy has been theoretically calculated as a function of sheet resistance of p‐ (GaAl)As and p‐GaAs, and also measured experimentally. The series resistance is strongly affected by the p‐layer sheet resistance. From the resistivity measurement, it was found that the resistivity of Zn‐doped p‐Ga0.3Al0.7As is about 10 times higher than that of the Zn‐diffused p‐GaAs layer. The high resistivity of Zn‐doped p‐Ga0.3Al0.7As is caused by the deeper acceptor level (Ea=90 meV) than that for Zn‐doped p‐GaAs (Ea=20 meV). Fabricated p‐p‐n solar cells have been operated under a concentration of 700 suns. The cells showed nearly constant efficiency at a concentration lower than 100 suns, but the efficiency decreased monotonically above 500 suns because of the series resistance effect. The additional Zn diffusion into p‐ (GaAl)As has also been performed after the LPE growth in a closed tube by using ZnAs2. The reduction of p...
TL;DR: In this paper, a theoretical model for relating the loss of power of a solar cell array to the mean value and standard deviation of the open-circuit voltage, short circuit current and series resistance of individual cells is presented.
TL;DR: In this paper, the dielectric response of sintered tantalum electrolytic capacitors under step function excitation in the time range 10 -1 -10 5 s nd under alternating signal in the frequency range 10 −3 -10 3 Hz, with temperature and amplitude of the applied signal or bias as parameters.
Patent•
08 Mar 1979
TL;DR: In this article, a class of two-terminal active networks which simulate low-noise temperature resistors is described, where either positive or negative simulated resistors can be obtained with a wide range of equivalent resistance values and effective noise temperatures.
Abstract: A class of two-terminal active networks which simulate low-noise temperature resistors is disclosed. A single field effect transistor or other suitable amplifier comprises the active element of the network. A dual transformer feedback arrangement or a single transformer feedback arrangement comprises the remainder of the circuit. Either positive or negative simulated resistors can be obtained with a wide range of equivalent resistance values and effective noise temperatures.
Patent•
02 Aug 1979
TL;DR: In this article, a step-recovery diode with a resistor connected between the diode and via a temp. controlled bias voltage is added to the rectified diode voltage at the resistor and increases with increasing temp.
Abstract: The frequency multiplier has a step-recovery diode with a resistor connected between the diode and via a temp. controlled bias voltage - a reference voltage. The reference voltage is added to the rectified diode voltage at the resistor and increases with increasing temp. Further resistors are connected in to stabilise the multipilier. For output frequencies higher than 500 MHz it is advantageous to form the series resistance by ferrite material placed in the magnetic field of the inductance.
Patent•
25 Oct 1979
TL;DR: The continuous temperature control for a hair dryer heating resistance (20) consists of a triac (2) switched on in a zero passage by a series resistance (3) at the output of a no-voltage circuit breaker (1) as mentioned in this paper.
Abstract: The continuous temperature control for a hair dryer heating resistance (20) consists of a triac (2) switched on in a zero passage by a series resistance (3) at the output of a no-voltage circuit breaker (1). The no-voltage circuit breaker (1) has a compensating resistance (4) and a diode (5) with an operating voltage of around twelve Volts at its input. The no-voltage circuit breaker (1) has a temperature sensor (10), a series resistance (11) and a continuously adjustable potentiometer (12), for the temperature regulator and signal.
TL;DR: Several alternative realizations are presented of s.c. inductors using one operational amplifier, which can be derived from a configuration reported previously.
Abstract: Several switched-capacitor circuits simulating grounded and floating inductors have been published recently. Several alternative realizations are presented of s.c. inductors using one operational amplifier, which can be derived from a configuration reported previously.
Patent•
18 May 1979
TL;DR: In this article, the authors proposed to realize highly-precise measurement under no influence of a series resistance and inductance except a reference resistance, by integrating a voltage across the reference resistance series-inserted into a series network composed of a resistance, inductance and capacity when extracting and measuring only the capacity of the network.
Abstract: PURPOSE:To realize highly-precise measurement under no influence of a series resistance and inductance except a reference resistance, by integrating a voltage across the reference resistance series-inserted into a series network composed of a resistance, inductance and capacity when extracting and measuring only the capacity of the network. CONSTITUTION:Reference resistance 10 is connected newly to the entrance side of resistance 11 of the series circuit composed of circuit 11, inductance 9 and measured capacitor 3. To both the sides of this resistance 10, the negative and positive input terminals of operational amplifier 12 are connected via resistances R0 and R1 respectively; and feedback capacitor C0 is connected to the negative input terminal, and grounded capacitor C1 is to the positive input terminal, thereby constituting the differential integrator. Next, a unit staircase wave of +Es volt is applied to input terminal 1, and the accumulated charge of measured capacitor 3 is calculated by equation (9), provided that a difference in potential across reference resistance 10 and reference resistance are denoted by vs(t) and Rs respectively. Consequently, the measurement value can be obtained accurately under no influence.
Patent•
23 Jun 1979
TL;DR: In this article, the authors proposed a method to eliminate adjustment work at the time of assembling by making equal the resistance values of the reference side series resistances of a temperature detecting resistance bridge and the detection side-series resistances and temperature detecting element in a temperature control unit of an electric refrigerator.
Abstract: PURPOSE:To achieve the elimination of adjustment work at the time of assembling by making equal the resistance values of the reference side series resistances of a temperature detecting resistance bridge and the resistance values of its detection side series resistances and temperature detecting element in a temperature control unit of an electric refrigerator, etc CONSTITUTION:If in a temperature detecting resistance bridge circuit 4 the resistance values of reference side series resistances 10, 11 are equal, the values of the reference potentials are kept constant among the assembled sets despite the use of resistances of different resistance values Likewise, if the resistance value at the set temperature of a temperature detecting element 12 and the resistance value of the detection side series resistance 14 are made equal, the temperature detecting potentials are also maintained constant and the set temperature becomes the operating temperature Hence, all required is to connect the resistances 14 of the resistance value equal to the resistance value of the element 12 at a desired temperature and there is no need for temperature adjustment work after assembling Since the respective resistances and temperature detecting elements of the bridge circuits are classified by resistance values and the classifications of the same resistance values are combined, the operating temperatures are controlled within a permissble range and the need for temperature adjustment after assembling of the apparatus is eliminated
Patent•
29 Jun 1979
TL;DR: In this paper, the authors proposed to shorten a measurement time by directly converting the Q value and series resistance value of a diode into resonance high-frequency voltage values by using a parallel resonance circuit, and then measuring the value and resistance value by converting them into DC voltage values.
Abstract: PURPOSE:To shorten a measurement time by directly converting the Q value and series resistance value of a diode into resonance high-frequency voltage values by using a parallel resonance circuit, and then by measuring the Q value and resistance value by converting them into DC voltage values CONSTITUTION:The measurement circuit is provided with oscillator 13 oscillating at a special measurement frequency and voltage, coupling capacitor 20, local oscillator 22, mixer 23, and intermediate-frequency amplifier 24 In addition, this is equipped with detector 25, circuit 26 operating as both a DC amplifier and highest- voltage holding circuit, DC voltmeter 27 for directly reading a Q value or series resistance and comparator circuit 28 In this constitution, high-frequency voltage e1 of oscillator 13 determined by Q or series resistance Rs of the diode is applied to mixer 23 and then transmitted in a form of an intermediate-frequency signal to amplifier 24 Next, this is detected and converted into a DC signal by detector 25, amplification-held by circuit 26, and read by voltmeter 27 simultaneously with the comparison by circuit 28, so that the Q value and resistance value Rs will be selectively discriminated
TL;DR: In this article, anomalies in DLTS response such as the appearance of double peaks, a rapid growth of transient response, and lack of exponential behavior as the depletion width extends into the buffer are discussed in terms of the planar geometry, the series resistance, and the multilayer nature of the devices.
Abstract: Majority‐carrier defects, induced by 1‐MeV‐electron irradiation in n‐type epitaxial GaAs were studied by deep‐level‐trap spectroscopy. The samples were fabricated in the form of FET‐like devices on the epitaxial active and buffer layers. Anomalies in the DLTS response such as the appearance of double peaks, a rapid growth of transient response, and lack of exponential behavior as the depletion width extends into the buffer are discussed in terms of the planar geometry, the series resistance, and the multilayer nature of the devices.
TL;DR: In this article, the front grid contact of GaAs solar cells for high efficiency concentrator applications is considered, and the junction depth is optimized by considering its effect on the collection efficiency of the dark currentvoltage characteristics or the open circuit voltage, and on the series resistance loss or the fill factor for material parameters.
Abstract: This communication considers the design of the front grid contact of np GaAs solar cells for high efficiency concentrator applications. This design involves shadowing, contact resistance, and active layer sheet resistance losses, and at high concentrations, the power loss due to voltage drop on the resistance of the grid fingers should be considered. Analysis of the performance can be calculated as a function of junction depth and surface recombination velocity. The junction depth can be optimized by considering its effect on the collection efficiency of the dark current-voltage characteristics or the open circuit voltage, and on the series resistance loss or the fill factor for material parameters. The choice of the material parameters, calculation of the short circuit current, the selection of the n layer thickness, and the cell maximum power and efficiency are discussed. It is concluded that optimized multi-grid structures should allow the use of 10 by 10 sq cm cells with good efficiencies at high concentration ratios, and efficiencies of 22 to 25% should be obtainable from large area cells at concentrations of 40 AM1.
01 Jan 1979
TL;DR: The theory of noise and frequency conversion in two-diode mixers is presented in this article, where the diodes are assumed to have non-linear conductance and capacitance, series resistance, and shot and thermal noise.
Abstract: The theory of noise and frequency conversion in two-diode mixers is presented. The diodes are assumed to have non-linear conductance and capacitance, series resistance, and shot and thermal noise. The series resistance can include a frequency dependent skin-effect component. Any linear embedding network is allowed. Computed examples are given showing the effect of the loop inductance in subharmonically pumped mixers.