FM response of quantum-well lasers taking into account carriertransport effects

The FM response of a single-frequency semiconductor laser is very important for communication systems that use direct modulation of the laser injection current. A new rate equation for the optical phase in quantum-well lasers is proposed, and the corresponding FM response is derived. It is shown that the separate-confinement-heterostructure can have a significant effect on the laser performance. The theory is confirmed with experimental results     

DFB laser intermodulation distortion analysis taking longitudinalelectrical field distribution into account

DFB laser intermodulation distortion were theoretically analyzed, taking longitudinal electrical field distribution in the laser cavity into account. The modulation distortion mechanism caused by longitudinal electrical field nonuniformity along the laser cavity was theoretically clarified. Furthermore, theoretical law distortion yields, which are decided by the uncontrollable grating phases at cleaved facets, were calculated for devices with various κL values and facet reflectivities, in order to obtain desirable design for the lasers used for subcarrier multiplexing     

SOI/SOS MOSFET compact macromodel taking into account radiation effects

A compact BSIMSOI-RAD macromodel for SOI/SOS CMOS transistors is developed that takes into account the radiation effects. An automated procedure for determination of macromodel parameters is described and shown to be useful for analyzing radiation hardness of CMOS IC fragments depending on the total absorbed dose. The simulation time is estimated.     

Dispersion study of open slot-lines taking into account conductor thickness and substrate width

By means of singular integral equations' method we've studied dispersion of open slot lines having nonstandard cross-section geometry. Peculiar dependence of eigenmodes' number and slot width between conductor strips has been found.     

One-dimensional analytical modeling of the VDMOS transistor taking into account the thermoelectrical interactions

We have modeled the influence of temperature on power Mosfet transistor behavior (vdmos transistor) in transient and static modes. The model we have developed is able to take into account temperature effects. Temperature is an interactive variable during the Saber simulations. With it, the designer knows the silicon chip temperature for a given application, and its influence on circuit performance or on the trend of a model parameter.     

Robust source decoding of variable-length encoded video data taking into account source constraints

We first provide an analysis of available redundancy remaining in compressed video data. This residual redundancy has two origins: the variable-length code (VLC) syntax and the source constraints. We compute the two in terms of equivalent redundancy bits. Then, a VLC decoding algorithm able to exploit both VLC syntax and source constraints for improving the decoding performance is outlined. Finally, it is shown that by taking this redundancy into account, video decoding over additive white Gaussian noise channels is substantially improved.     

Optimization of the structure of gallium-arsenide-based detectors with taking into account recombination losses

The model describing the physical processes accompanying the interaction of heavy charged particles with an ionizing-radiation semiconductor detector is proposed. The problem of optimization of electrical characteristics and construction of the detector cell is solved. The model makes it possible to calculate the output current of the detector as a function of its active-region’s thickness and the voltage applied across the sensor under conditions of the presence of recombination processes.     

Improvement of model kernel representation in process simulation by taking pattern correlation into account

In the modern photolithography simulation, the computation demand on resolution enhancement techniques (RETs) and optical proximity corrections (OPCs) is proportional to the simulation runtime of the model, which is dependant on the number of the kernels retained with the constrain of the model accuracy. Thus, it is essential to retain as few kernels as possible in the model calibration. Traditionally, the kernels are retained based upon their contribution to the aerial image, which is solely determined by the magnitudes of the eigenvalues. This method works well for arbitrary photolithography masks. However, real masks are never arbitrary and random. Instead, they have regular shapes and arrangements as governed by design rules, indicating the contributions from the retained kernels are statistically correlated to each other. By taking such correlations into account, the system representation can be improved to contain fewer kernels for a constant model accuracy. In this paper, the mathematical derivation of the pattern correlation concept is discussed and the concept is applied to a contact layer illuminated by a Quasar optical system with λ = 193 nm and NA = 0.8. Significant improvement of model kernel representation is observed, four improved kernels vs 15 original kernels, and the new methodology is justified by comparing the difference of the aerial image intensities between the full kernel representation and the retained kernels representation at sampling points.     

考虑腔内光强高斯分布时调Q激光器的速率方程及其解

在主动调Ｑ激光器速率方程中考虑腔内光强的高斯分布,数值求解该速率方程得至归一化的脉冲能量、峰值功率和脉冲宽度与泵浦条件之间的关系,并做图表示,同时与采用平面波近似时所得结果进行比较,并对相关问题进行讨论。     

PLL design technique by a loop-trajectory analysis taking decision-circuit phase margin into account for over-10-Gb/s clock and data recovery circuits

A design technique for an over-10-Gb/s clock and data recovery (CDR) IC provides good jitter tolerance and low jitter. To design the CDR using a PLL that includes a decision circuit with a certain phase margin affecting the pull-in performance, we derived a simple expression for the pull-in range of the PLL, which we call the "limited pull-in range," and used it for the pull-in performance evaluation. The method allows us to quickly and easily compare the pull-in performance of a conventional PLL with a full-rate clock and a PLL with a half-rate clock, and we verified that the half-rate PLL is advantageous because of its wider frequency range. For verification of the method, we fabricated a half-rate CDR with a 1:16 DEMUX IC using commercially available Si bipolar technology with f/sub T/=43 GHz. The half-rate clock technique with a linear phase detector, which is adopted to avoid using the binary phase detector often used for half-rate CDR ICs, achieves good jitter characteristics. The CDR IC operates reliably up to over 15 Gb/s and achieves jitter tolerance with wide margins that surpasses the ITU-T specifications. Furthermore, the measured jitter generation is less than 0.4 ps rms, which is much lower than the ITU-T specification. In addition, the CDR IC can extract a precise clock signal under harsh conditions, such as when the bit error rate of input data is around 2/spl times/10/sup -2/ due to a low-power optical input of -24 dBm.     

Two-dimensional numerical simulation of bipolar semiconductor devices taking into account heavy doping effects and Fermi statistics

A numerical method for the solution of steady-state equations describing the processes in heavy doped bipolar devices is proposed. The calculations were carried out for Fermi as well as Boltzmann statistics. The dependence of heavy doping effects on injection level was taken into account as well. It is shown that the current gain values obtained using different statistics may differ remarkably in the case of large donor and acceptor concentrations at the emitter-base junction (Nd = Na ≈ 10¹⁸cm^?3).     

Load-pull measurement analysis of AlGaN/GaN HEMT taking into account number of gate fingers

This paper investigates load-pull measurement of AlGaN/GaN high electron mobility transistors (HEMTs) at different numbers of gate fingers. Scalable small-signal models are extracted to analyze the relationship between each model''s parameters and the number of device''s gate fingers. The simulated S-parameters from the small-signal models are compared with the reflection coefficients measured from the load-pull measurement system at X-band frequencies of 8.8 and 10.4 GHz. The dependency between the number of device''s gate fingers and load-pull characterization is presented.     

Estimation of formalized message bringing in broadband channel taking into account useful signal searching time

It is estimated bringing time of formalized message in broadband channel, taking into account synchronization establishing time. We show, if signal to noise ratio is greater than four, a probability of correct information finishing at definite time is practically independent on information repetition number.     

Extremely short electromagnetic pulse in a superlattice taking into account field inhomogeneity along its axis

The propagation of a two-dimensional electromagnetic pulse in a semiconductor superlattice is investigated. For the first time, inhomogeneity of the pulse field along the superlattice axis is taken into account. The electromagnetic-field evolution and the charge density in a sample are described with the help of the set of Maxwell equations and the continuity equation. As a result of numerical modeling, the possibility of propagation of the two-dimensional electromagnetic pulse in the superlattice is shown. It is established that the propagation of the electromagnetic pulse results in redistribution of the electron concentration in the sample.     

Recombination constants and alpha factor in 1.5 mu m MQW optical amplifiers taking carrier overflow into account

Recombination constants, carrier lifetime, linewidth enhancement factor and related parameters are examined experimentally and theoretically for MQW semiconductor optical amplifiers. The theoretical model which takes carrier overflow into account predicts a band-to-band recombination constant of B=10/sup -10/ m/sup 6//s and an Auger recombination constant of C=15*10/sup -29/ m/sup 6//s which is higher than previously reported for MQW devices. Furthermore, linewidth enhancement factors up to 30 are measured.<>     

A novel analytical approach to parameter extraction for on-chip spiral inductors taking into account high-order parasitic effect

We present an analytical approach to extract model parameters for silicon on-chip spiral inductors taking into account various high-order parasitic effects such as skin effect and substrate coupling. The parameters for the series branch were extracted using iterative analytical calculations, and parameters for the substrate branch were extracted using a modified linear characteristic-function approach via the introduction of a partition rule. As demonstrated by a series of inductors fabricated using 0.18 μm CMOS process, simulations can provide a high-precision fit with experimental data over a broad frequency range between 0.1 and 10 GHz.     

Use of point contributors model for a radar target taking into account mutual coupling by double reflection

In a previous letter we showed that the electromagnetic mutual coupling between two diffractive bodies can considerably modify the radar cross-section diagram of these bodies. We commented on the preponderance of mutual coupling by double reflection and established a new formula for the RCS of a system of two spheres, giving excellent results in practice. In this letter, we shall propose a generalisation of the previously established formulas, and shall give a law of composition for the contributions fit for use with the complex models of specular point contributors. In the second Section we shall show how it is possible to replace a model of isotropic point contributors with couplings by a model without coupling by adding imaginary isotropic points.     

Development of a mathematical model for optimizing the design of an automotive thermoelectric generator taking into account the influence of its hydraulic resistance on the engine power

A complex of models for optimizing the design and operation modes of an automotive thermoelectric generator is developed within the proposed approach taking into account the influence of hydraulic resistance of the generator on the internal combustion engine. Several designs of generators for converting the thermal energy of exhaust gases (EGs) of internal combustion engines into electricity due to the Seebeck effect in semiconductor elements, which have different geometries of the continuous-flow part of the generator with different hydraulic resistances, are considered. Models for calculating the thermoelectric elements, gas heat exchanger, and automotive engine are considered jointly. Simulation is performed using the example of a VAZ-21126 engine, which demonstrated that up to 500 W of electric power can be obtained using semiconductor thermoelectric elements based on germanium and lead tellurides.     

The ground field of arbitrarily shaped linear antennas ofgeostationary satellites in polar regions taking into account astochastic and anisotropic ionosphere

The propagation of electromagnetic waves from satellites to the earth is influenced by the electrically anisotropic behavior of the ionosphere. Fluctuating ionospheric parameters cause perturbations in the signal. To calculate the ground field of arbitrarily shaped linear antennas of geostationary satellites for polar regions, the passage of a carrier wave through a homogeneous, electrically anisotropic, stochastic ionosphere imbedded in a two-dimensional three-layer model (near-earth space, ionosphere, atmosphere) is considered. Perturbations due to the ionospheric fluctuations are treated using B.J. Uscinski's multiple scatter theory (see The Elements of Wave Propagation in Random Media, McGraw Hill, 1977) which has been extended to anisotropic media. Finally, the theory of E. Arbel and L.B. Felsen (see Electromagnetic Theory and Antennas Part I, Pergamon, 1963, p.391-420) is applied to derive field representations for the more realistic case of a homogeneously stratified anisotropic ionosphere