Showing papers on "Equivalent series resistance published in 1994"

Method and apparatus for differentiating battery types

Abstract: The cell type of a battery is determined by characterizing the series resistance behavior of various cell types to determine ranges of series resistance values exhibited by batteries of a particular cell type The series resistance of a battery of unknown cell type is then measured If the series resistance measurement is determined to be within a range of series resistance values exhibited exclusively by a cell type, the battery is identified as having that cell type However, for batteries whose series resistance measurements are within a non-exclusive range of series resistance values, a second cell type discharge characteristic such as battery voltage is also characterized to differentiate between the cell types The second discharge characteristic of these batteries is also measured and used to identify the cell type

Form and capacitance of parallel-plate capacitors

Abstract: In basic electrostatics, the formula for the capacitance of parallel-plate capacitors is derived, for the case that the spacing between the electrodes is very small compared to the length or width of the plates. However, when the separation is wide, the formula for very small separation does not provide accurate results. In our previously published papers, we used the boundary element method (BEM) to derive formulas for the capacitance of strip and disk capacitors that are applicable even when the separation is large. In this paper, we present results and formulas for the capacitances of square and rectangular capacitors. >

Monolithic narrow-band filter using ultrahigh-Q tunable active inductors

Abstract: A tunable active inductor is presented where the novel topology enables both the inductance and series resistance to be varied. With a discrete MMIC realization of this active inductor, Q-factors in excess of 15000 have been measured over a wide range of inductance values. Applications for these active inductors include high-performance narrow-band filters, voltage controlled oscillators, and analog phase shifters. Analytical equations for the novel active inductor and a 3-resonator filter are given. The measured performance for a monolithic 2 GHz filter achieves a mean insertion loss of 0.9 dB, passband ripple of /spl plusmn/0.7 dB, with a 3 dB bandwidth of 70 MHz, and an excellent out-of-band rejection which exceeds 50 dB up to 18 GHz. >

Monolithic narrow-band filter using ultrahigh-Q tunable active inductors

Abstract: A tunable active inductor is presented where the novel topology enables both the inductance and series resistance to be varied. With a discrete MMIC realization of this active inductor, Q-factors in excess of 15 000 have been measured over a wide range of inductance values. Applications for these active inductors include high-performance narrow-band filters, voltage controlled oscillators, and analog phase shifters. Analytical equations for the novel active inductor and a 3-resonator filter are given. The measured performance for a monolithic 2 GHz filter achieves a mean insertion loss of 0.9 dB, passband ripple of ±0.7 dB, with a 3 dB bandwidth of 70 MHz, and an excellent out-of-band rejection which exceeds 50 dB up to 18 GHz

Observation of intrinsic tristability in a resonant tunneling structure

Abstract: A new technique has been developed to probe the region of apparent bistability due to a tunneling resonance in the characteristic of a semiconductor asymmetric double‐barrier structure. The measuring circuit uses a voltage supply designed to have a load line with positive slope, equivalent to a voltage source and negative series resistance. The appearance of bistability and hysteresis in the characteristic is an artifact of the conventional measuring technique, which employs a load line with negative slope. The complete characteristic is found to be a continuous Z‐shaped curve between 50 and 150 K, corresponding to tristability. Equivalent circuit models for the device and voltage supply predict a narrow range of circuit parameters for which a static operating point exists inside the tristable region.

Recessed-channel structure for fabricating ultrathin SOI MOSFET with low series resistance

Abstract: A new recessed-channel SOI (RCSOI) technology has been developed for fabricating ultrathin SOI MOSFET's with low source/drain series resistance. Thin-film fully depleted SOI MOSFET's with channel film thickness of 72 nm have been fabricated with the RCSOI technology. The new structure demonstrated a 70% reduction in source/drain series resistance compared with conventional processes. In the deep-submicron region, more than 80% improvement in saturation drain current and transconductance over conventional devices was achieved using the RCSOI technology. The new technology would also facilitate the use of silicide for further reducing the series resistance. >

High-frequency models of ferrite core inductors

Abstract: A model of ferrite core inductors is presented. The skin and proximity effects which increase the ac resistance of the inductor winding are considered. The core losses are studied. Power losses of the inductor are modeled by means of a frequency dependent series resistance. Parasitic capacitances which affect the inductor high-frequency operation are also considered. The model is applicable to cores with and without an air gap. Calculated and measured inductor parameters such as equivalent series inductance (ESL), reactance, equivalent series resistance (ESR), impedance magnitude and phase, and quality factor are plotted as functions of the operating frequency and compared. Calculated results were in good agreement with the measured ones up to the inductor self-resonant frequency. As a consequence, the discussed model is suitable to represent the frequency response of ferrite core inductors and can be effectively used for designing inductors. >

1.1 GHz oscillator using bondwire inductance

Abstract: Using the parasitic inductance usually associated with a bondwire in an IC package, a bipolar GHz LC-tuned oscillator is designed. Bondwires have very low series resistance and are thus suitable for high-Q applications. Measured results indicate very low phase noise and low power consumption.

Single-Electron Tunnelling at Room Temperature with Adjustable Double-Barrier Junctions

Abstract: Ultrasmall double-barrier junctions with capacitance 10-19-10-18 F were realized in a system consisting of a metallic substrate, an insulating thin organic film, an isolated metal particle, an adjustable tunnelling gap and the tip of a scanning tunnelling microscope (STM). These structures were characterized by STM topography and local current-voltage (I-V) measurements at room temperature. We found clear evidence of Coulomb blockade effects in the I-V characteristics which could readily be explained in terms of simulations based on the semi-classical theory of single-electron tunnelling. The charging energies and resistances derived from our experiments clearly exceed the theoretical limits of thermal energy and resistance quantum required for observing single-electron tunnelling. By varying the STM gap we also verified the dependences of the particle capacitance and of the double-barrier series resistance.

Control of variable active-passive reactance (VAPAR) and negative inductance

Abstract: The concept of the variable active-passive reactance (VAPAR) which behaves like a two-terminal reactive element, and the produced active reactance works as a passive reactive component, including in transient state. In this paper, the authors propose the equivalent resistance control method for the capacitor DC voltage regulation when a capacitor is used as an energy storage element of the VAPAR. The series equivalent resistance is added to the produced virtual inductance, and the capacitor voltage is controlled by changing the series equivalent resistance. The proposed scheme is verified by simulations and experiments. The realization of the negative inductance is then proposed. Through simulations and experiments, it is verified that the VAPAR can generate negative inductance, which may be applied to FACTS. The effects of negative inductance are compared with that of series capacitance used in power systems. >

Planar millimeter-wave microstrip lumped elements using micro-machining techniques

Abstract: Planar millimeter-wave microstrip inductors and capacitors have been fabricated on high-resistivity silicon substrates using micro-machining techniques. The spiral inductors and interdigitated capacitors are suspended on a thin dielectric membrane to reduce the parasitic capacitance to ground. The resonant frequencies of a 1.2 nH and a 1.7 nH inductor fabricated on a high-resistivity silicon substrate and on a small dielectric membrane, have been increased from 22 GHz and 17 GHz to 73 GHz and 54 GHz, respectively. The planar micro-machined elements are compatible with the via-hole technology process in GaAs and InP MMIC, and can be used as true inductors and capacitors up to 50-60 GHz. The technique can be also applied to lumped elements in coplanar-waveguide transmission lines. >

High-temperature stability of refractory-metal VLSI GaAs MESFETs

Abstract: Commercially available, self-aligned VLSI GaAs MESFETs, with tungsten-based refractory-metal Schottky gates, nickel-based refractory-metal ohmic contacts, and aluminum interconnection metallization, have been thermally cycled and shown to be stable after 3 h at temperatures up to 500/spl deg/C. Both partially processed and fully processed wafers were found to be stable with no significant change occurring in either Schottky gate or ohmic contact properties. An increase in the channel resistance component of the series resistance is believed to be responsible for I/sub DS/ and g/sub m/ degradation above 500/spl deg/C. The fact that commercially available, gold-free VLSI GaAs MESFETs are able to withstand such thermal cycles has very important consequences for monolithic optoelectronic integrated circuit (OEIC) fabrication because it means that it may now be feasible to grow photonic device heterostructures epitaxially on MESFET VLSI wafers; process them into lasers, modulators, and/or detectors; and interconnect them with the electronics to produce VLSI-density OEICs. >

Self-consistent thermal-electrical modeling of proton-implanted top-surface emitting semiconductor lasers

Abstract: A new comprehensive thermal-electrical self-consistent model of proton-implanted top-surface-emitting lasers is described. The model is applied to study thermal characteristics of GaAs/AlGa As/AlAs devices with the active-region diameter of 35 micrometers . Our results show that intense heating occurs at pumping currents exceeding 4X threshold. Long tails of radial temperature distribution will result in severe thermal crosstalk if integration of these devices into densely packed 2D arrays were to be attempted. Minimization of electrical series resistance is shown to be very important for improving the device performance.

Tantalum chip capacitor reliability in high surge and ripple current applications

Abstract: Relentless miniaturization of electronic circuitry and the general movement from through-hole to surface-mount manufacturing have generated explosive growth in the use of surface mount tantalum chip capacitors. Many of these applications involve substantial exposure to surge and ripple currents. Such exposure invites questions regarding the impact of surge and ripple current on the long-term reliability of tantalum chip capacitors. To facilitate a better understanding of the impact of surge and ripple current on tantalum chip capacitor reliability, theoretical analyses of generic circuits are supported with discussion of experimental data. Simple circuits that highlight the fundamental theoretical principles behind transient surge and steady-state ripple current applications are analyzed and pertinent reliability issues are discussed. The relationship of device ESR (equivalent series resistance) to surge and ripple current robustness and device temperature rise is established theoretically. Surge and ripple current test and measurement methods are briefly discussed and experimental test data are used to support many of the insights that are drawn from theory. >

Optimization of series resistance in sub-0.2 /spl mu/m SOI MOSFET's

Abstract: The optimization of device series resistance in ultra-thin film SOI devices is studied through 2-D simulations and process experiments. The series resistance is dependent on the contact resistivity of the silicide to silicon and the silicide geometry. To achieve low series resistance, very thin silicides that do not fully consume the SOI film are needed. A novel cobalt salicidation technology using titanium/cobalt laminates is used to demonstrate sub-0.2 /spl mu/m, thin-film SOI devices with excellent performance and very low device series resistance. >

Ultra-thin film SOI/CMOS with selective-epi source/drain for low series resistance, high drive current

Abstract: A self-aligned selective epitaxial technique is used to overcome the high source/drain resistance problem in ultra-thin film SOI/CMOS devices. Very low series resistances, comparable to those for bulk CMOS devices, are demonstrated with this selective-epi source/drain. >

Means and method of enhancing signal resolution and dynamic range extension in a pulse width modulation amplifier

Abstract: An amplifier (1) used with a pulse width modulated signal which improves the efficiency of a low level input signal comprises two or more switching devices (7,9) with common source/drain or emitter/collector connections. The gates or the bases of the devices are independently driven to optimize the efficiency of the various Rds (on) resistance values of the transistors (61, 63, 65, 89, 91, 93) used in the devices. The amplifier is operated so that during the highest output levels, select switching devices (61, 63, 65) are utilized to reduce in series resistance with the load (13). As output power decreases, devices (89, 91, 93) with higher Rds (on) resistance values are activated by a control signal which greatly improves DC to DC conversion efficiency with improved output voltage resolution, dynamic range and reduced electromagnetic interference potential.

Series resistance and effective channel length extraction of n-channel MOSFET at 77 K

Abstract: A simple method is presented to extract the effective channel length and series resistance of n-channel MOSFETs having 0.6-2.0 mu m mask channel lengths at room and liquid nitrogen temperatures. Our results show that the effective channel length increases and the series resistance decreases when the temperature is reduced from 300 to 77 K.

A novel fabrication process and analytical model for Pt/GaAs Schottky barrier mixer diodes

Abstract: A new fabrication process for small-area honeycomb structured GaAs Schottky barrier diodes is described This fabrication process is based on the anodic pulse etching technique of GaAs in combination with an electrolytic in situ Pt deposition The presented diodes exhibit nearly ideal I/V and noise characteristics An analytical model has been developed to self-consistently model the fabricated near-ideal Schottky barrier diodes The analytical model includes the effects of a current dependent recombination velocity, an accurate derivation of the spreading resistance for epitaxial diodes, a n-n + junction voltage dependent on the diode current and a bias dependent barrier height A closed-form expression for the recombination current in the depletion region is given This model, compared to the simple thermionic model is able to determine technology dependent parameters such as the bias dependent series resistance and junction capacitance as well as the current dependent noise temperature These are the most important diode parameters which define the diode mixing performance Although the simple thermionic model also fits the measured data very well, it is shown that the physical parameters of the Schottky diodes, determined by this approach, are inaccurate The novel analytical model gives new insight into the physical understanding of forward biased epitaxial Schottky diodes with small junction areas

Numerically generated resonant tunneling diode equivalent circuit parameters

Abstract: We present results from a numerical solution of a resonant tunneling diode structure, using a time‐independent Schrodinger equation without considering scattering. Intrinsic circuit parameters such as conductance, capacitance, and inductance are extracted from the numerical results and compared with experimental data obtained from dc and microwave characterization of GaAs/AlGaAs devices. A study of the influence of different lightly doped spacer layer thicknesses on the emitter side reveals the relationship between spacer layer thickness and the circuit parameters. From these results, we provide explanations for the behavior of the biased diode circuit parameters. The simulated data show good qualitative agreement with experimental results; possible explanations for deviations between experimental values and simulated data, including inelastic scattering and series resistance effects, are discussed.

The waffle: a new photovoltaic diode geometry having high efficiency and backside contacts

Abstract: By employing anisotropic etching techniques and advanced device processing it is possible to micromachine new types of mechanical, electronic, and optical devices of silicon, which have unique properties In this paper the characteristics of a new type of photovoltaic diode fabricated employing these processing techniques are described This novel device has not only high efficiency, but also has both contacts placed on the backside of the cell The first devices which are only 50 mm in diameter are of relatively good quality with low leakage currents (nA), high breakdown voltages (80 V), and low series resistance (mohms) The measured efficiencies at AM 15 lie between 12 to 15% with short circuit currents of 25-30 mA/cm2, and open circuit voltages of 058-06 V

Series resistance in polysilicon contacted solar cells

Abstract: Series resistance values between 0.2 and 0.43 /spl Omega/ cm/sup 2/ have been obtained in solar cells contacted with polysilicon in 2.6% of the area. These values include the resistance of the polysilicon-single crystal silicon interface. Various size devices were fabricated in 4" wafers, and a VLSI polysilicon emitter technology was applied to fabricate polysilicon contacts to the emitter front surface. The polysilicon-silicon interface was produced using either an HF etch or RCA clean before polysilicon deposition and half of the wafers were implanted with fluorine to assess the passivating effects on the polysilicon-silicon interface. The drive-in time of the impurities from the polysilicon into the silicon was also varied. The main results are that the series resistance is lower in all fluorinated samples, either HF or RCA. The series resistance decreased monotonically in the HF devices as the drive-in time increased from 20' to 80' whereas little change is seen in RCA devices.

High-voltage electronic switching circuit

Abstract: A high-voltage switching circuit is formed of a series combination of switches, each of which is rated for use at a voltage lower than that of the power supply. The switches are connected in series with inductors, the inductors being magnetically coupled, in an anti-phase manner. A pair of capacitors, having substantially equal values of capacitance, are connected, respectively, in parallel with each series combination of a switch and inductor. The inductors and capacitors together insure that no more than one-half the total voltage of the power supply will ever appear across either switch. The series combination of switches can be used in place of a single switch, and permits the use of switches rated at low voltage to be combined to form an overall switch which works reliably at a higher voltage.

Low drive voltage GaAs quantum well electroabsorption modulators obtained with a displaced junction

Abstract: A reduction in the drive voltage of an electroabsorption waveguide modulator based on an AlGaAs/GaAs quantum well laser heterostructure is demonstrated by a simple change in the position of the p-n junction relative to the quantum well. This is accomplished by adjusting the doping profile and does not significantly alter the operation of the structure as a laser or degrade other aspects of device performance such as reverse breakdown voltage and series resistance. A contrast ratio of 25 dB (5 dB/100 /spl mu/m) was obtained with a bias change of -2 V. >

Decrease of inductance and electromagnetic interference in power electronics capacitors

Abstract: Pierron and Glaize (1992) have demonstrated that it is possible to decrease drastically parasitic inductances of wiring in commutation cells. But the inductance of capacitors still remains. Furthermore, in power electronics, problems of capacitors' inductance are well known: peaks of voltage in snubber capacitors (L dI/dt); output voltage ripples; perturbations in DC power supplies; low self-resonant frequencies (beyond this frequency, capacitors behave like an inductance), reduction of the lifetime of the whole circuit; switching capacitor disruption of operation of adjustable-speed drives; and especially electromagnetic interference (EMI). Here, from the study of standard capacitors, the authors have looked for solutions to reduce both inductance and EMI.

The effect of annealing on the resistance of a p/i/n structure

Abstract: The purpose of this paper is to investigate the effect of annealing on the series resistance Rs and the shunt resistance Rsh of a p/i/n type solar cell made of a-Si:H thin films in a SnO2/a-SiC:H(p-type)/a-Si:H/a-Si:H(n-type)/Al sandwich structure. The series resistance and the shunt resistance were determined from DC current-voltage (I-V) characteristics by means of Warashina's method. Thermal annealing carried out in the temperature range 70-175 degrees C showed that the series resistance Rs decreased and the shunt resistance Rsh increased with increasing annealing temperature.