Interface electric charge modelling and characterization with δ - distribution generator strings in thin SOI films

Today's SOI technologies are able to produce buried oxides with a thickness spectrum from 400 nm in the standard HTA SIMOX, down to tens of nm in Unibond technique. In the SOI structures, two oxide-semiconductor interfaces exist, with specific associated charges. Conventional models ignore the charges situated at the buried oxide-substrate interface, being focused just on the front and back channels conduction in the silicon film. All these fixed charges, classically expressed in e cm⁻², are physically spread into a small volume that becomes significant in very thin films (nanofilms). This paper presents a new model of the flat-band voltage using δ-distribution generator strings. The model accuracy increases in the SOI nanofilms domain, accordingly with our theory and numerical simulations. On the other hand, an experimental setup is presented for the spreading parameters extraction, in the case of a HTA SIMOX wafer.     

水情自动测报系统遥测站低功耗设计研究

针对水情自动测报系统运行环境和特点,分析了影响遥测站功耗的主要因素,详细阐述了器件选型、电源控制、远程通信、软件编程等关键环节进行低功耗设计的策略与实现方法。据此设计的数据采集器在现场得到广泛运用,验证了本方法的有效性和实用性。     

Stabilisation procedure for electric field integral equation

A stabilisation procedure for the electric field integral equation (EFIE) is developed which renders the EFIE stable with respect to the discretisation interval used to numerically solve the equation. Representative numerical examples are provided which demonstrate the effectiveness of the procedure     

A space-time discretization criterion for a stable time-marchingsolution of the electric field integral equation

Numerical techniques based on a time-domain recursive solution of the electric field integral equation (EFIE) may exhibit instability phenomena induced by the joint space-time discretization. The above problem is addressed with specific reference to the evaluation of electromagnetic scattering from perfectly conducting bodies of arbitrary shape. We analyze a particular formulation of the method of moments which relies on a triangular-patch geometrical model of the exterior surface of the scattering body and operates according to a “marching-on-in-time” scheme, whereby the surface current distribution at a given time step is recursively evaluated as a function of the current distribution at previous steps. A heuristic stability condition is devised which allows us to define a proper time step, as well as a geometrical discretization criterion, ensuring convergence of the numerical procedure and, therefore, eliminating insurgence of late-time oscillations. The stability condition is discussed and validated by means of a few working examples     

A numerical implementation of a modified form of the electric field Integral equation

The details of a Galerkin discretization scheme for a modified form of the electric field integral equation are outlined for smooth, three-dimensional, perfectly conducting scatterers. Limitations of the divergence conforming finite-element bases in preserving the self-stabilizing properties of the electric field integral equation operator are indicated. A numerically efficient alternative is outlined which relies on an operator-based Helmholtz decomposition. The condition number of the resulting matrix equation is demonstrated to be frequency independent for scattering from a perfectly conducting sphere at various frequencies.     

A stable solution of time domain electric field Integral equation for thin-wire antennas using the Laguerre polynomials

In this paper, a numerical method to obtain an unconditionally stable solution of the time domain electric field integral equation for arbitrary conducting thin wires is presented. The time-domain electric field integral equation (TD-EFIE) technique has been employed to analyze electromagnetic scattering and radiation problems from thin wire structures. However, the most popular method to solve the TD-EFIE is typically the marching-on in time (MOT) method, which sometimes may suffer from its late-time instability. Instead, we solve the time-domain integral equation by expressing the transient behaviors in terms of weighted Laguerre polynomials. By using these orthonormal basis functions for the temporal variation, the time derivatives can be handled analytically and stable results can be obtained even for late-time. Furthermore, the excitation source in most scattering and radiation analysis of electromagnetic systems is typically done using a Gaussian shaped pulse. In this paper, both a Gaussian pulse and other waveshapes like a rectangular pulse or a ramp like function have been used as excitations for the scattering and radiation of thin-wire antennas with and without junctions. The time-domain results are compared with the inverse discrete Fourier transform (IDFT) of a frequency domain analysis.     

Improved temporal basis function for time domain electric field integral equation method

An improved stable procedure is presented for time domain electric field integral equations. The procedure employs a new temporal basis function, which makes the time derivative of the unknown current density continuous. Numerical examples that demonstrate the efficacy of the proposed procedure are presented.     

情景模式背景下电力应急演练仿真平台研究

合理的电网结构、坚强的一次设备以及可靠的二次设备是保证电力系统安全稳定运行的基础和前提,考虑到电力系统事故影响的严重性,应该尽可能做好事故预防工作,建立相应的电力系统应急体系,通过电力应急演练的方式,及时发现应急体系中存在的问题并对其进行解决.本文提出了一种基于情境模式的电力应急演练仿真平台方案,对于应急演练的展开和应急模式的制定具有一定的指导意义.     

A procedure for solving the electric field integral equation for adielectric scatterer with a large permittivity using face-centered nodepoints

A numerical procedure for solving the electric field integral equation (EFIE) using the pulse-basis block model is proposed. The main features of the method are the use of face-centered node points and a unique way of choosing the unknown fields. Such a procedure keeps the resulting matrix relatively well conditioned even when the magnitude of the permittivity is large. In addition, the procedure can preserve the convolution property contained in the EFIE and, hence, the fast Fourier transform can be incorporated into the algorithm     

细线结构时域电场积分方程的有限差分求解

提出一种求解基于细线结构的时域电场积分方程 ( TDEFIE)的方法 -有限差分方法。与传统求解时域电场积分方程的时域矩量法相比 ,该方法易于数值实现。文中还利用该方法研究了电磁辐射、散射的三个经典问题 ,并将结果与时域矩量法的结果进行了比对 ,研究表明 ,该方法求解细线结构的 TDEFIE非常有效。     

A comparison of electric field-strength standards for the frequencyrange of 30-1000 MHz

Published results about site attenuation and transmission loss measurements as well as antenna factor calculations and calibrations are summarized. The antenna types discussed are precision dipoles, a microstrip patch antenna, open-ended waveguides, and horn antennas as well as TEM-cells. The best values for agreement between theory and experiments that were reported for the transmission losses were in the range of 0.25-0.4 dB. An experimental comparison between precision reference dipoles and a TEM-cell that was performed in the Seibersdorf calibration laboratory is described with deviations of no more than 0.15 dB in the antenna factor or field-strength     

A resist for electric imprint lithography

An electrically curable resist has been developed that can make electric imprint lithography (EIL) a reality. The resist is composed of a diaryliodonium salt photo acid generator and a cycloaliphatic epoxy monomer. Its polymerization takes place when an electric potential is applied between a conductive imprint mold and a substrate which sandwich the resist. A proof-of-concept pattern transfer by EIL with a micron-scale resolution has been demonstrated.     

A differential equation for placement analysis

A first-order differential equation for placement analysis is derived by considering the competing processes that generate and terminate wires crossing a circuit partition. The solution of this equation provides an estimate for the number of wires needed by a circuit partition for external communication and corresponds to the information normally associated with Rent's rule. The rate model is shown to account not only for the simple power-law form of Rent's rule for small partition sizes but also for deviations from power-law behavior observed for larger partition sizes. The accuracy of the model is validated by comparing solutions of the differential equation with experimental data extracted from a variety of netlists. The netlists, ranging from 10000 to 68000 cells, were optimized using a commercial placement tool. The accurate modeling of terminal-cell data results in a more robust predictive model for the distribution of wire lengths. This improved model accurately captures the change in the distribution of wires as the level of circuit placement optimization ranges from random to highly optimized placement. In addition, the new model provides an explanation for the experimentally observed inflection point and local maximum in the wire length distribution of some netlists     

Physical and analytical properties of a stabilized electric field integral equation

The physical and analytical properties of a stabilized form of the electric field integral equation are discussed for closed and open perfectly conducting geometries. It is demonstrated that the modified equation provides a well-conditioned formulation for smooth geometries in both the high- and low-frequency limits; an instability remains near the edges of open geometries, requiring future consideration. The surface Helmholtz decomposition is used to illustrate the mechanism of the stabilization procedure, and the relevance of this mechanism to the numerical discretization of the equation is outlined.     

A Matlab-based modeling and simulation package for electric andhybrid electric vehicle design

This paper discusses a simulation and modeling package developed at Texas A&M University, V-Elph 2.01. V-Elph facilitates in-depth studies of electric vehicle (EV) and hybrid EV (HEV) configurations or energy management strategies through visual programming by creating components as hierarchical subsystems that can be used interchangeably as embedded systems. V-Elph is composed of detailed models of four major types of components: electric motors, internal combustion engines, batteries, and support components that can be integrated to model and simulate drive trains having all electric, series hybrid, and parallel hybrid configurations. V-Elph was written in the Matlab/Simulink graphical simulation language and is portable to most computer platforms. This paper also discusses the methodology for designing vehicle drive trains using the V-Elph package. An EV, a series HEV, a parallel HEV, and a conventional internal combustion engine (ICE) driven drive train have been designed using the simulation package. Simulation results such as fuel consumption, vehicle emissions, and complexity are compared and discussed for each vehicle     

A terrain parabolic equation model for propagation in thetroposphere

A method to model tropospheric radiowave propagation over land in the presence of range-dependent refractivity is presented. The terrain parabolic equation model (TPEM), is based on the split-step Fourier algorithm to solve the parabolic wave equation, which has been shown to be numerically efficient. Comparisons between TPEM, other terrain models (SEKE, GTD, FDPEM), and experimental data show predominantly excellent agreement. TPEM is also compared to results from an experiment in the Arizona desert in which range-dependent refractive conditions were measured. Although horizontal polarization is used in the implementation of the model, vertical polarization is also discussed