共查询到20条相似文献,搜索用时 13 毫秒
1.
Yu S.F. Plumb R.G.S. Zhang L.M. Nowell M.C. Carroll J.E. 《Quantum Electronics, IEEE Journal of》1994,30(8):1740-1750
The large-signal behavior of DFB lasers is analyzed, including lateral as well as longitudinal variations in carrier density, photon density, and refractive index. The effective index method and other approximations are used to reduce the complex three-dimensional problem to one dimension. The coupled wave and carrier rate equations are then solved in a self-consistent manner. Lateral spatial carrier hole burning and lateral diffusion are found to affect the relaxation oscillation frequency and damping rate of DFB lasers, depending on their detailed structure. The effective time-averaged linewidth enhancement factor is also affected. In symmetric AR-coated λ/4 phase-shifted lasers the side mode suppression ratio can be deteriorated significantly by lateral spatial hole burning when kL is large 相似文献
2.
The forward converter with the active-clamp reset offers many advantages over the forward converters with other transformer-reset methods. However, during the line and load transients, the maximum magnetizing current of the transformer and the peak voltage of the primary switch are strongly affected by the active-clamp circuit dynamics. As a result, the design of a forward converter with the active-clamp reset cannot be optimized based only on its DC characteristics. Due to the nonlinearity of the circuit, it is very difficult to derive the closed-form equations for the transient response of the active-clamp circuit. In this paper, an average-state-trajectory approach is proposed to analyze the transient behavior so that the trends of the maximum magnetizing current of the transformer and the peak voltage of the primary switch can be easily predicted under worst-case conditions and parameter variations 相似文献
3.
《Electron Devices, IEEE Transactions on》1972,19(3):364-375
The growth of a space charge in bulk GaAs with a uniform doping profile but with a highly and three-dimensionally non-uniform electric field has been analyzed by introducing a concept of a "carrier current tube." From this analysis it has been shown how the behavior (i.e., growth or decay) of a small space charge depends upon the magnitude of an initial space charge, the nonuniformity of the field, and the dielectric relaxation time and that a space charge grows where the electric field changes along the carrier current even if no initial space charge exists. The "lateral spreading velocity" of a dipole domain has been estimated (its value is the order of 108cm/s) and its dependence upon the magnitude of an initial domain has been made clear. Furthermore, computer simulation have been performed for bulk GaAs devices with two-dimensional structure, such as a planar electrode, a nonuniform doping profile, and an imperfect cathode notch. The process of two-dimensional dipole domain formation in these devices has been made clear. 相似文献
4.
《Electron Devices, IEEE Transactions on》1957,4(3):220-225
The transient signal which results from the characteristics of a low-velocity electron beam and the capacitance of the scanned surface has been calculated. A very slow transient of the hyperbolic type can result if the scanned surface is stabilized at a retarding field potential. The calculations have been verified by tests on a 6198 Vidicon, which was taken as an example. For this tube, the relative contributions of the "electronic transient" and the photoconductive decay to the observed transient response were determined. They make comparable contributions to the total transient. 相似文献
5.
Various aspects of the overload signal stability of s.e.c. targets, formed from good and poor secondary-emitting materials, are considered. It is shown that a target consisting of two layers can be made to be inherently stable to signal overload, while still having a high gain. 相似文献
6.
《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1968,56(10):1727-1728
A nonlinear transient effect in avalanche diodes is proposed. In this effect, carriers in a bunch sweep across the depletion region, ionizing as they go, and leaving behind an electric field substantially lower than the initial field, and too low to allow further ionization. 相似文献
7.
《Electron Devices, IEEE Transactions on》1986,33(8):1098-1106
Three-dimensional computer simulation demonstrates the principles used in the design of electron guns for color television tubes. A deformable-mesh finite difference analysis provides the electron trajectories from the cathode to the center of the screen. At the screen, the dimensions of the spot are obtained from the edge trajectory and from profiles of the current in the beam. Comparisons with measurements for three tubes show that the aspect ratios of the horizontal and vertical spot diameters agree within 14 percent or better. The computed beam currents are accurate to about 10 percent, and the optimum focus voltages to within 200 V. 相似文献
8.
《Solid-State Circuits, IEEE Journal of》1970,5(5):261-265
The rate of dark current increase of silicon-diode-array camera- tube targets has been found to be as high as 10 nA/h when operated with electrode potentials as high as 1000 volts. Irradiation of the target by soft X-rays is shown to cause the fast-state density at the silicon-silicon dioxide interface to increase. The increased fast-state density is largely responsible for the increased dark current. The X-rays are generated by the impact of the returning electron beam upon high-potential tube electrodes. Several means for reducing the X-ray flux at the target are discussed. The most effective means is a reduction in tube electrode potentials to low values where dark current aging rates as small as 0.001 nA/h have been achieved. 相似文献
9.
The rigorous numerical analysis of charge partitioning in a simple p-n junction structure is presented. Procedures for extracting the relevant terminal charges, based upon the concept of a “pass-through” current, are introduced. The calculation of the pass-through current, the electrostatic displacement current and the (distinct) current associated with the changes in internal charge distributions are described. Methods for dividing the various internal charges into “quasineutral” and “space-charge” components, are also presented. The results obtained by exact analysis are compared with the predictions of the conventional, analytic, charge partitioning models. Significant discrepancies are found to arise from the simplifications necessary for analytic modeling such as the dependence of the partitioning on the ramp speed and injection level and asymmetry between switch-on and switch-off transients. The numerical simulation results offer guidance for the future development of alternative, more accurate, nonquasi-static device models 相似文献
10.
《Electron Devices, IEEE Transactions on》1960,7(2):78-83
Several new information storage targets have been developed for use in storage tubes and camera tubes. One, a double-sided mosaic, is useful primarily in storage tubes. The others, based upon the use of thin self-supported films of magnesium oxide, can be used in many tubes. Having first found application in image orthicons, they provide markedly improved performance and longer life. 相似文献
11.
It is shown that the gain obtainable by coherent amplification using two-wave mixing in BSO crystals is limited by nonlinear effects. A model based on a generalisation of existing theories is presented, giving the dependence of gain coefficient on input beam ratio and leading to good agreement with experimental results. 相似文献
12.
In the letter experimental results are presented which show that distributed amplifiers can be used for power applications. These results are verified by comparing an analytic model predicted using SPICE 2 simulation with measurements between 0.3 and 12 GHz. It appears that a very broad band can be achieved and that the distributed amplifiers keep their self matching properties even under large-signal operation. Distributed-amplifier characteristics, under small-signal operations, are now well known.1?4 However, recent improvements in GaAs FET technology have created new prospects in large-signal and high-frequency conditions. To our knowledge, although some experimental results have been published3, no theoretical study has been carried out for large-signal conditions. The letter provides such a study. 相似文献
13.
This work presents a study on the effects of Single Event Transients on Successive Approximation Register Analog-To-Digital Converters (ADC) based on charge redistribution. The effects of SETs are analyzed by means of an extensive fault injection campaign by using a SPICE simulator and a predictive 130nm CMOS technology model. Faults are injected in the analog blocks and in the digital control circuit of the converter. Results show that the transient effects may change the state of one or more bits of conversion, since the affected conversion stage may propagate an incorrect value to the remainder of the conversion, leading to multiple bit errors on the converted data. Results also allow to identify the most sensitive nodes and the failure mechanisms associated to transient effects on this type of converter. Finally, some design-level mitigation strategies are applied, in a way that the error rate and the magnitude of conversion errors are significantly reduced. 相似文献
14.
《Electron Devices, IEEE Transactions on》1972,19(4):557-562
This paper describes two types of electroprinting tubes, one of which has been applied to television facsimile. The electrostatic printing tube and fiber-optics printing tube have a resolution of 8 lines/mm and 15 lines/mm, and a writing speed of 200 m/s and 1700 m/s, respectively. The electron scanning method utilizing the fiber-optics printing tube showed good results in experimental television facsimile. 相似文献
15.
16.
《Solid-State Circuits, IEEE Journal of》1974,9(3):111-117
Advantageous use of the silicon, diamond cubic crystal structure is described from the aspect of orientation-dependent etching. The use of this technology can affect device characteristics, device and circuit isolation, circuit element densities, and process control. Several laboratories have reported advantageous use of }100{ oriented silicon. This paper discusses the advantageous use of both {100} and {110} silicon orientations. In particular, the {110} technology is discussed from a high packing density aspect as applied to the processing and characteristics of silicon diode array targets with improved television blooming control. 相似文献
17.
An exact solution is presented to the problem of current spreading in the resistive layer of stripe geometry DH lasers. Computed examples demonstrate that the customary one-dimensional treatment of the resistive layer or the assumption of constant current density distribution under the stripe contact are not always justified. 相似文献
18.
The authors present a comprehensive large-signal stability analysis of a solar-array power system. The stability of the equilibrium points of a system with a typical nonlinear load characteristic is analyzed. Employing state-plane analysis techniques, the dynamic behavior of the system from an arbitrary initial condition is characterized, and the region of the desired stable operation is identified. The stability and transient response of the system operation near the solar array's maximum power point are evaluated. The dynamic response of the spacecraft power system operating in the shunt mode and battery-discharge mode is analyzed 相似文献
19.
A nonlinear device characterized by a noninteger power-law equation is considered. Amplitudes and phases of output harmonic and mixing components are determined for the case where the device is driven by several arbitrarily phased frequency components. The resulting expressions are shown to have close ties with the Gaussian hypergeometric function. 相似文献
20.
《Electron Devices, IEEE Transactions on》1971,18(11):1075-1086
The effect of beam interception on the initial-energy distribution of the electrons contributing to the operating beam and on the imaging in camera tubes is examined. It is shown that the imaging properties of different imaging systems can be compared mutually by calculating their figure of merit, which is defined as the product of beam angle and spot diameter. The beam acceptance by the low-potential target depends on the imaging system used in the tube. This is clearly demonstrated by calculations on three different imaging systems, the imaging properties of which are compared with one another. These systems have been chosen such that: 1) the influence of the Coulomb interactions between individual electrons on the beam acceptance is of minor importance; and 2) the initial-energy distributions of the beam electrons are different particularly in the low-energy region. This gives rise to differences in the lag for peak white in the three systems which are calculated. The importance of these differences depends on operating conditions and layer capacitance. It is shown that a space-charge minimum between mesh and target, which could affect the beam acceptance, does not occur at normal values of the mesh potential and of the distance between mesh and target. The influence of increasing the beam angle on the beam acceptance is calculated and found, to give rise to a paralell shift of the acceptance curve which looks like the effect of an increasing contact potential difference. 相似文献