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Ray-based and hybrid propagation models are today considered as valuable solutions to fulfill 5G wireless channel modeling requirements. They are a complement or alternative to the stochastic approaches when link-level and system-level simulations deal with millimeter-wave (mmWave), ultra-dense deployment and/or large antenna arrays. The present article proposes an extension of an urban ray-based...
One of the most relevant challenges of next generation in-body devices consists in enhancing the medical applications of wireless networks qualitatively. The current standard does not allow high data rate wireless connections between implanted nodes. UWB systems have been considered as a potential candidate for future in-body devices. To establish a proper link within UWB, antenna matching should...
A gradient index lens is designed by utilizing quasi-conformal transformation electromagnetics (QCTEM) to define the index distribution in a rotationally symmetric lens. The smooth and continuous nature of QCTEM is investigated and an analytical surrogate model is trained to replace the computationally intensive QCTEM procedure and ray trace simulations. The surrogate model is then incorporated into...
The interaction between electromagnetic waves and complex media and its consequences on other physical phenomena such as hyperthermia is a crucial issue for various types of applications. To name a few, electromagnetic compatibility, microwave ovens design, medical applications, and the design of electromagnetic devices and circuits that include lossy media. In this article, we present a full-wave...
Uncertainty quantification has become a hot topic in computational sciences in the last decade. Indeed computer models (a.k.a simulators) are becoming more and more complex and demanding, yet the knowledge of the input parameters to feed into the model is usually limited. Based on the available data and possibly expert knowledge, parameters are represented by random variables. Of crucial interest...
This paper is focused on the statistical analysis of the human indoor exposure induced by a WLAN source (often named “box”) located close to the walls of a room of 3∗4 m2. The exposure is firstly assessed by using a hybridize method combining the spherical wave description and the FDTD numerical method. A scenario, where the anatomical model is located in unknowing room position and the source is...
Wireless Power Transfer (WPT) technology is one of the most promising application for charging the batteries of electric vehicles. The exposure assessment of human body to the stray electromagnetic fields emitted by WPT devices is a critical issue which can limit the spreading of this technology in everyday life. In this paper, a numerical dosimetric study was carried out to evaluate the electric...
The performance of GPS (Global Positioning System) in densely built urban areas is greatly undermined due to multipath propagation. Many attempt alternative means for urban navigation, of which the ‘fingerprinting’ method has drawn much attention recently. However, the labor of site surveys and a constantly changing environment prevents ‘fingerprinting’ from being an eificient solution. Therefore,...
Availability of fast yet reliable replacement models (also referred to as surrogates) is essential to reduce the computational cost of antenna design process. Unfortunately, conventional approximation (or data-driven) modeling is not well suited for modeling of highly nonlinear responses of antenna structures, especially for larger number of geometry parameters. The latter is due to the so-called...
New developments in energy efficient wireless communications systems and indoor location and tracking algorithms have created a greater demand for accurate propagation models. In this paper a frequency domain full wave propagation model is used to produce accurate power delay profile information. The propagation model is based on the volume electric field integral equation (VEFIE). The VEFIE is solved...
The surface electric and magnetic susceptibilities and the surface impedance of an array composed of periodic scatterers are derived based on generalized sheet transition conditions. Using these characteristic parameters, the reflection coefficient of a reflectarray element can be readily computed for arbitrary incident angles, polarizations, and frequencies. The detailed procedure is described and...
This paper describes a reliable methodology for radar cross section (RCS) measurement of complex small and large targets in the W band. The backscattering behavior of a small car model was measured in an anechoic chamber along with various automotive related targets in a wide gymnasium. Experimental performance in the anechoic chamber is compared to the simulation results. Our simulation model is...
We present a fully automated method to predict the full radiation patterns and S-parameters of antennas over a large frequency bandwidth using the knowledge of the simulated results at a few frequency points. The frequency points are adaptively selected in regions of fast variations of radiation pattern and S-parameters, as well as in large unsampled regions. The method has a built-in absolute error...
Multi-objective optimization yields indispensable information about the best possible design trade-offs of an antenna structure, yet it is challenging if full-wave electromagnetic (EM) analysis is utilized for performance evaluation. The latter is a necessity for majority of contemporary antennas as it is the only way of achieving acceptable modeling accuracy. In this paper, a procedure for accelerated...
In this paper, size reduction of antenna structures taking reflection response and total efficiency into account has been investigated. In order to find available design trade-offs concerning the antenna footprint, its wideband matching, and efficiency, numerical optimization has been employed. Appropriate formulation of the objective function permits identification of the designs that exhibit the...
The simulation of EM (electromagnetic) wave propagation requires considerable computation time, as it analyzes a large number of propagation paths. To overcome this problem, we propose a GPU (graphics processing unit)-based parallel algorithm for VPL (vertical plane launch)-approximated EM wave propagation. The conventional algorithm computes the gain along propagation paths with irregular memory...
For a little over a decade now, a measurement and post-processing technique named Mathematical Absorber Reflection Suppression (MARS) has been used successfully to identify and then suppress range multi-path effects in spherical [1, 2, 3, 4], cylindrical [5, 6, 7] & planar [8, 9] near-field antenna measurement systems and far-field [10] and compact antenna test ranges [11] with a detailed theoretical...
This paper introduces a new high-speed 2.5D deterministic radio propagation model. This model is suitable for outdoor urban configurations where transmitter and receiver nodes are below the rooftop level of the surrounding buildings. This model can provide narrow-band and wide-band predictions. In this paper we combine three acceleration strategies in order to achieve a high-speed site-specific urban...
This paper studies the accuracy and limitations of different electromagnetic (EM) simulation approaches for dielectric radar benchmark targets. In comparison to perfect electric conductors (PEC), dielectric targets are much more complex from an EM point of view. However, dielectric materials are widely used for modern aircraft and unmanned aerial vehicles (UAVs). Apart from that, EM simulation tools...
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