IEEE Journal on Multiscale and Multiphysics Computational Techniques

This paper develops an innovative Multiphysics modeling of a microstrip line excited by high voltage. The introduced model enables us to calculate the Multiphysics phenomenon which cannot be performed with most of the electrical circuit simulation tools. The system understudy is assumed as anRLCtransmission line (TL) with resistive load excited by input pulse wave voltage. The modeling conc... View full abstract»

This paper presents a multiphysics modeling of pin-socket under uniaxial vibration stress. The pin-socket behaves as a typically cylindrical dynamic contact structure as a function of the stress events. The pin-socket contact resistance fluctuation is expressed under the configuration of ideal, arbitrary roughness, and degraded surface contacts. To treat the problem, the pin slip is assumed to be ... View full abstract»

The dissipative quantum electromagnetics is introduced in a comprehensive manner as a field-matter-bath coupling problem. First, the matter is described by a cluster of Lorentz oscillators. Then the Maxwellian free field is coupled to the Lorentz oscillators to describe a frequency dispersive medium. The classical Hamiltonian is derived for such a coupled system using Lorenz gauge and decoupled sc... View full abstract»

We present a nonconformal surface integral equation method for the analysis of time-harmonic electromagnetic scattering by multiscale perfect electrically conducting (PEC) objects. To alleviate the burden of geometrical processing, a mixed triangle/quadrilateral mesh with arbitrary nonconformity is adopted in this method. A vectorial piecewise constant basis function is defined over the unstructur... View full abstract»

Metasurfaces represent one of the most vibrant fields of modern science and technology. A metasurface is a complex electromagnetic structure, which is typically deeply subwavelength in thickness, electrically large in transverse size, and composed of subwavelength scattering particles with extremely small features; it may generally be bianisotropic, space-varying and time-varying, nonlinear, curve... View full abstract»

Applications involving quantum physics are becoming an increasingly important area for electromagnetic engineering. To address practical problems in these emerging areas, appropriate numerical techniques must be utilized. However, the unique needs of many of these applications require new computational electromagnetic solvers to be developed. The $\mathbf... View full abstract»

The properties that quantify photonic topological insulators (PTIs), Berry phase, Berry connection, and Chern number, are typically obtained by making analogies between classical Maxwell's equations and the quantum mechanical Schrödinger equation, writing both in Hamiltonian form. However, the aforementioned quantities are not necessarily quantum in nature, and for photonic systems they can be exp... View full abstract»

A high-intensity electric pulse with subnanosecond and picosecond durations may induce electroporation of an intracellular organelle while the integrity of plasma membrane in a biological cell remains intact. In this paper, selective electroporation of organelles under intense picosecond electric pulse (psEP) is theoretically studied. We construct a simplified axisymmetric model of a biological ce... View full abstract»

A new method for making an explicit time-domain finite-element method unconditionally stable is developed for general electromagnetic analysis, where the dielectrics and conductors can be inhomogeneous, lossless, or lossy. In this method, for a given time step, we find the unstable modes that are the root cause of instability, and deduct them directly from the system matrix resulting from a time-d... View full abstract»

This paper compares the standard and exponential differencing's on time used with the finite-difference time-domain (FDTD) method in such lossy media as conducting media and plasma media. It is shown that the performances of the two differencing's are quite close, concerning both the accuracy of the computed results and the domain of validity of the FDTD method in lossy media. There is no particul... View full abstract»

In this work, we study a joint inversion algorithm to reconstruct acoustic and electromagnetic data in biomedical imaging. This algorithm is based on contrast source inversion algorithm (CSI). We define contrast source and contrast functions in both acoustics and electromagnetics, respectively, and apply two reciprocal regularization operators to link acoustic and electromagnetic inversion. By min... View full abstract»

The interaction between electromagnetic field and plasmonic nanostructures leads to both strong linear and nonlinear behaviors. In this paper, a time-domain hydrodynamic model for describing the motion of electrons in plasmonic nanostructures is presented, in which both surface and bulk nonlinearity are considered. A coupled Maxwell-hydrodynamic system capturing full-wave physics and free-electron... View full abstract»

A fast and memory efficient three-dimensional full-wave simulator for analyzing electromagnetic (EM) wave propagation in electrically large and realistic mine tunnels/galleries loaded with conductors is proposed. The simulator relies on Muller and combined field surface integral equations (SIEs) to account for scattering from mine walls and conductors, respectively. During the iterative solution o... View full abstract»

A discontinuous Galerkin time-domain method (DGTD) enhanced with exact absorbing boundary conditions (EACs) for characterizing transient electromagnetic interactions on periodic three-dimensional (3-D) gratings is proposed. The EACs are derived rigorously and discretized using a high-order scheme in space and time. The periodic boundary conditions (PBCs) under oblique incidence are also discussed.... View full abstract»

Inspired by the new fast Fourier transform subspace-based optimization method (NFFT-SOM), wavelet transform subspace-based optimization method (WT-SOM) that represents the minor part of induced current by wavelet bases is proposed in this paper to solve the inverse scattering problem. This paper provides a guideline for choosing the appropriate bases for the minor part of induced current in the in... View full abstract»

Electromagnetic telemetry (EMT) systems are utilized for measurement while drilling to transmit data from borehole to the ground surface during drilling or vice versa. To help predict the successful deployment of the EMT system within complex formation and environmental noise, a reliable numerical algorithm is developed and applied to model the EMT system for directional drilling in layered transv... View full abstract»

In this paper, the efficient methods for calculating the scattered fields from the electrically large scatterers and multiscale scatterers are discussed. The method of moment physical optics (MoM-PO) method is introduced to obtain the scattered fields from the multiscale scatterers. Due to the highly oscillatory behavior of the PO integrals, the numerical contour deformation technique is proposed ... View full abstract»

The objective of this paper is to illustrate that computational electromagnetics can be used very effectively to improve the accuracy and efficiency of antenna pattern measurements. This is accomplished by moving a single probe over the measurement plane to generate the enhanced accuracy in planar near-field (NF) to far-field (FF) transformation than over the classical Fourier-based modal expansio... View full abstract»

The electrical response of an antenna-coupled nanothermocouple depends on how well the antenna converts incident optical energy to heat, and how this heat is converted to electrical signals by the nanothermocouples. In this paper, we study by COMSOL simulations the heat dissipated in dipole antennas operating at 600 GHz to maximize the temperature at the center of the antenna where the nanothermoc... View full abstract»

Quantization of the electromagnetic field has been a fascinating and important subject since its inception. This subject topic will be discussed in its simplest terms so that it can be easily understood by a larger community of researchers. A new way of motivating Hamiltonian mechanics is presented together with a novel way of deriving the quantum equations of motion for electromagnetics. All equa... View full abstract»

In this paper, Multirate Partial Differential Equations (MPDEs) are used for the efficient simulation of problems with 2-level pulsed excitations as they often occur in power electronics, e.g., DC-DC switch-mode converters. The differential equations describing the problem are reformulated as MPDEs which are solved by a Galerkin approach and time discretization. For the solution expansion two type... View full abstract»

Modeling of terahertz plasmonic device is a multiscale and multiphysics problem that requires fine mesh in the electron transport regions, inevitably leading to long simulation times. In this paper, we tackle this problem by employing unconditionally stable FDTD methods for these simulations. Specifically, we present alternating direction implicit (ADI) FDTD and iterative-ADI-FDTD based efficient ... View full abstract»

A task-oriented multiscale material synthesis problem is addressed through an instance of the system-by-design (SbD) paradigm. More specifically, wide-angle impedance matching (WAIM) layers based on printed metasurfaces are designed to enhance the radiation efficiency of planar phased arrays. Toward this end, a task-oriented formulation is adopted where the layer geometrical features are the micro... View full abstract»

In this work, we develop a method of extracting structural information of the breast from ultrasound signals and integrating this information into microwave radar based image reconstructions. The synergistic combination of these modalities exploits the dielectric contrast between breast tissues at microwave frequencies and short wavelengths of ultrasound signals to enhance the imaging resolution a... View full abstract»

An adaptive h-refinement algorithm is investigated for the electric field integral equation applied to a conducting missile target. The process incorporates the advancing front Delaunay algorithm to refine the triangular-cell surface mesh in conjunction with Laplacian smoothing to maintain the mesh quality. The performance of several error estimators used to guide the refinement process is compare... View full abstract»