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Item type:Publication, Access status: without files , Numerical investigation of orbital angular momentum density of antenna arrays based on the method of moments(2018-06-22); ; ; In this contribution antenna arrays that radiate electromagnetic fields showing orbital angular momentum (OAM) are being studied. We investigate the spatial distribution of normalized OAM densities on hemispheres for two types of circular dipole antenna arrays operating at 100 MHz both in free space and close to an electrical conducting plane, respectively. Comprehensive simulations were performed based on the Method of Moments (MoM) and an explanation of the generation of OAM based on fields is given. To the knowledge of the authors similar studies have not been performed before. The results show that OAM density is a highly complex quantity and further research is necessary to exploit OAM in radio communication and to understand its potential for and susceptibility to electromagnetic interference.Publicationtype: Conference Paper141 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Efficient modeling of multi-coil wireless power transfer systems using combination of full-wave simulation and equivalent circuit modelingWireless power transfer (WPT) systems have proven to be very efficient for short-range and mid-range distances, but the transmission efficiency reduces rapidly when the distance is increasing. Multi-coil design based on magnetic resonance can be used to improve the efficiency when the distance is larger than 10 times the diameter of the coils. However, it takes a long computation time when analyzing WPT systems consisting of multiple coils in full-wave simulations. In this paper, a combination of equivalent circuit modeling (ECM) and 3D full-wave modeling based on the method of moments (MoM) is proposed to reduce the calculation time from days to minutes on a today's PC while the calculation accuracy remains acceptable. An optimization of a multi-coil WPT system is carried out with the proposed technique. For long transmission distances, the highest efficiency can be obtained with multiple coils of the same size and an optimum number along the transmission distance. It has to be ensured that the pitch between adjacent coils is equal to the diameter of the coils.Publicationtype: Conference Paper183 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Feasibility of uncertainty quantification for power distribution network modeling using PCE and a contour integral method(2018-06-22); ; ; ; This work presents the modeling of the printed circuit board part of power distribution networks (PDNs) and example results for the uncertainty quantification for the magnitude of the corresponding impedance. Variability is considered for several parameters, including geometry, material properties, and the models of the decoupling capacitors. For the computation of the parallel plate impedance an efficient and accurate two-dimensional contour integral method (CIM) is applied together with models for the wave number for the complete frequency range of interest. Polynomial chaos expansion (PCE) is used in the non-intrusive form of stochastic testing for the uncertainty quantification and Monte Carlo simulations are used for the validation of these results. To our knowledge this combination of methods represents the first application of CIM and PCE to the modeling of PDNs. The PCE is found to be numerically more efficient than Monte Carlo in cases where parameters are varied that have an influence on the parallel plate impedance. It can be less efficient for variation of only the models of decoupling capacitors. It is applicable if not too many parameters are varied at a time and accurate if resonance effects due to low-loss substrate materials and components are not too pronounced at the considered frequency.Publicationtype: Conference Paper214 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Investigation of Radiated EMI from Printed Circuit Board Edges up to 100 GHz by Using an Effective Two-Dimensional Approach(2018-10-05); Problems of the radiated EMI from printed circuit board (PCB) edge have been widely studied for a long time. However, most of those publications stay in the frequency lower than 20 GHz. With the development of high-speed communication and some new generation telecommunication technologies, the operating frequency is moving higher and higher. This paper investigates the radiated EMI from PCB edge up to 100 GHz, by using the full-wave simulation. To simplify the study, the PCB has been modeled as a two-dimensional (2D) approach by using periodical boundary. The impacts of different PCB parameters, such as the substrate thickness, dielectric constant, dielectric loss and multi-layers, have been studied in this paper, together with a 3D PCB model for reference. It's found that the PCB thickness and the dielectric constant affect the edge radiation a lot. For instance, the radiation of the PCB with 0.508 mm thickness increases by 0.06 dB/GHz, whereas the one with 1.524 mm thickness increases by 0.22 dB/GHz.Publicationtype: Conference Paper150