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With a 3D spatial spectral integral-equation method for EM scattering from finite objects, a significant part of the computation time is spent on a middle region around the origin of the spectral domain. Especially when the scatterer extends to more than a wavelength in the stratification direction, a fine discretization on this region is required, consuming much computation time in the transformation...
We demonstrate a compact design for enhancing the 3dB beamwidth of a 60 GHz single-chip millimeter-wave frequency modulated continuous wave (FMCW) radar with integrated on-chip antennas. We use thin (Xfreespace/5) dielectric periodic lenses on top of the epoxy cover of the single-chip radar to change the effective material properties of the epoxy, which changes the field distribution and hence the...
A 3D semi-analytical harmonic modeling technique is presented, that is able to model magnetic fields in the vicinity of a rectangular slab of permeable material accurately. A stable solution for the constitutive relation for magnetic fields in the spectral domain is described, which makes it possible to incorporate a spatially varying permeability of a certain region in the solutions of magnetic-field...
The layered-medium model is used in modeling scattering by various media such as biological tissue and distributed Bragg reflectors. The impurities and imperfections of the real media are described in the model by adding uncertainties to them. Common ways to estimate the effect of these uncertainties on the behavior of the media are often time consuming. Here we present a method by which we can approximate...
Stacks of dielectric slabs serve as models of a large variety of engineering structures such as Bragg gratings and Vertical-Cavity Surface-Emitting lasers (VCSELs). Depending on the application, design features that describe the electromagnetic response of the structure are chosen. Subject of study in this paper is the effect of uncertainties in the material properties of the slabs. Design features...
During a hyperthermia treatment, a tumour is locally heated for a defined period of time by focussing the energy of electromagnetic waves into it. Hyperthermia treatment planning (HTP) consists of finding optimal amplitudes and phases for the antenna array of the applicator to realize this objective. Current optimization methods for HTP are time-consuming and not very flexible. In this paper we present...
For a wave propagating in and through a 1-dimensional inhomogeneous dielectric slab with stochastic properties, we investigate the effectiveness of intrusive polynomial chaos as a way to characterize stochastic aspects of the resulting electric field inside the slab and compare the numerical effort to compute these characteristics to traditional sampling approaches such as the Monte-Carlo method.
In this paper, we address the problem of computing estimates of the variability of “observables.” Observables are measurable quantities which are defined as the integral of an appropriately chosen electromagnetic field against a (current-) distribution. The latter is obtained by solving a boundary value problem. In the case of an uncertain boundary geometry, the current distribution underlying the...
Boundary integral equations for bodies of revolution have a Green's function kernel that can be written as the azimuthal integral over the free-space Green's function. We show that existing approximation methods for computing this integral suffer from efficiency or stability problems. Improvement of one of these methods leads to controllable accuracy while retaining efficiency.
We present a hybrid modeling approach for the modeling of 2D-waveguides in layered media based on an embedding envelope. The inner domain is treated spatially, and the outer domain is treated partly spatially for the direct terms, and partly spectrally for the reflected terms.
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