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  • 51.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Antonini, G.
    University of L’Aquila.
    Ruehli, A.E.
    T. J. Watson Research Center, Yorktown Heights, NY.
    Toward improved time domain stability and passivity for full-wave PEEC models2006In: 2006 IEEE International Symposium on Electromagnetic Compatibility: [2006 IEEE EMC] ; Portland, Oregon, USA, 14 - 18 August 2006, Piscataway, NJ: IEEE Communications Society, 2006, Vol. 2, p. 544-549Conference paper (Refereed)
    Abstract [en]

    It is well known that time domain integral equation techniques may suffer from stability problems and frequency domain models may provide non-passive results. A main source of these issues is the delay of the coupled elements. In the classical Partial Element Equivalent Circuit (PEEC) method, a single delay was used for each couple of partial element which results in a delay differential equation with reduced stability and accuracy. In this paper, we consider multiple delay coefficients which can be used for both the time and frequency domain. Also, filters are introduced which remove unwanted eigenvalues or resonances in the partial element couplings. This can substantially improve the response of the frequency domain and the time domain models. Stability improvements also means passivity improvements.

  • 52.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Antonini, Giulio
    University of L’Aquila.
    On characterizing artifacts observed in PEEC based modeling2004In: EMC 2004: E2004 IEEE International Symposium on Electromagnetic Compatibility : EMC from DC to daylight : [symposium record] : 09 August-13 [sic], 2004, Silicon Valley, California, Piscataway, NJ: IEEE Communications Society, 2004, p. 251-255Conference paper (Refereed)
    Abstract [en]

    This paper characterizes the different artifacts observed within time- and frequency- domain partial element equivalent circuit based electromagnetic modeling. The main focus is on frequency domain artifacts since time domain instabilities have been treated extensively in the literature. Guidelines and examples are given on how to suppress this type of artifact by showing correlation to PEEC model geometrical meshing and PEEC model complexity reduction.

  • 53.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Antonini, Giulio
    Department of Electrical Engineering, University of L’Aquila.
    Tutorial on Partial Element Equivalent Circuit (PEEC) method based analysis of EMC problems2014Conference paper (Other academic)
    Abstract [en]

    As a tool for prediction of electromagnetic field phenomena in electric and electronics design, the Partial Element Equivalent Circuit (PEEC) method has received a great interest over the last years. Besides being a powerful full-wave 3-d numerical method which competes with other popular techniques (FDTD, FEM,MoM) it is especially suited for mixed electromagnetic circuit problems, in both the time and frequency domains. The recent literature is confirming that the PEEC method is becoming more and more popular in EMC-EMI-Signal Integrity areas especially for its capability to combine electromagnetic fields and lumped elements in the same numerical framework [1]–[3]. Furthermore its recent extension to magnetic materials and the development of fast solvers have made it powerful and well tailored for a comprehensive treatment of EMC problems.The aim of the tutorial is to present the basic theory of the method up to the most recent advancements of the technique. Furthermore, in order to make it easier for the audience, a step-by-step implementation of the method clarifying the key points to make it fast and efficient will be presented. The tutorial will be subdivided into three sections, dealing with:1) History of PEEC. Inductance calculations from Rosa through Grover to Ruehli;2) Most recent progress of the method (acceleration techniques, dispersive dielectrics, and magnetic materials);3) Circuit and electromagnetic co-simulation for active, non-linear circuit systems.

  • 54.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Antonini, Giulio
    University of L’Aquila.
    Miscione, Giuseppe
    University of L’Aquila.
    Anttu, Peter
    Electromagnetic modeling of automotive platforms based on the PEEC Method2007In: Proceedings of the Applied Computational Electromagnetics Society Conference: ACES 2007, 2007Conference paper (Refereed)
  • 55.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Antonini, Giulio
    University of L’Aquila.
    Orlandi, Antonio
    University of L’Aquila.
    3D PEEC capacitance calculations2003In: 2003 IEEE International Symposium on Electromagnetic Compatibility: symposium record : Boston, August 18-22, 2003, Piscataway, NJ: IEEE Communications Society, 2003, p. 630-635Conference paper (Refereed)
    Abstract [en]

    The partial element equivalent circuit (PEEC) method has shown to be useful in mixed circuit and electromagnetic analysis. In PEECs, the extensions from two to three dimensional modeling are mainly in the calculation of the partial self and mutual capacitive couplings. The considerable increase in problem size for 3D PEEC models results in a larger number of partial elements that has to be calculated. This results in excessive calculation times if the capacitive calculation routines are poorly constructed. In this paper it is shown that by using local reduction matrices for the capacitive calculations, the calculation time for PEEC model capacitance matrices can be decreased while keeping the accuracy.

  • 56.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Antonini, Giulio
    University of L’Aquila.
    Orlandi, Antonio
    University of L’Aquila.
    Full-wave time domain PEEC formulation using a modified nodal analysis approach2004In: EMC Europe 2004: International Symposium on Electromagnetic Compatibility; September 6 - 10, 2004, Technische Universiteit, Eindhoven, the Netherlands / [ed] A. P. J. van Deursen, Eindhoven: Technische Universiteit Eindhoven, 2004Conference paper (Refereed)
  • 57.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Antonini, Giulio
    University of L’Aquila.
    Orlandi, Antonio
    University of L’Aquila.
    Integral order selection rules for a full wave PEEC solver2003In: Electromagnetic compatibility 2003: symposium proceedings and supplement, Zürich: ETH Zentrum - IKT , 2003, p. 431-436Conference paper (Refereed)
    Abstract [en]

    This paper proposes a technique to re- duce the calculation time for the complex partial el- ements used in a retarded partial element equivalent circuit (rPEEC) frequency domain solver. The tech- nique utilizes a thresholding scheme where strongly coupled PEEC cells are calculated with higher accu- racy than the weakly coupled. Guidelines for limiting the order of integration used in the evaluation of the complex partial elements are presented. The trade-o® between accuracy and computation time of the par- tial elements and the resulting PEEC system solution is investigated and displayed.

  • 58.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Antonini, Giulio
    University of L’Aquila.
    Orlandi, Antonio
    University of L’Aquila.
    Ruehli, Albert E.
    IBM T.J. Watson Research Center, Yorktown Heights.
    Impact of partial element accuracy on PEEC model stability2006In: IEEE transactions on electromagnetic compatibility (Print), ISSN 0018-9375, E-ISSN 1558-187X, Vol. 48, no 1, p. 19-32Article in journal (Refereed)
    Abstract [en]

    This paper details the impact of partial element accuracy on quasi-static partial element equivalent circuit (PEEC) model stability in the time domain. The potential sources of inaccurate partial element values are found to be poor geometrical meshing and the use of unsuitable partial element calculation routines. The impact on PEEC model stability of erroneous partial element values, and the coefficients of potential and partial inductances, are shown as theoretical constraints and practical results. Projection meshing, which is a discretization strategy suitable for the PEEC method, is shown to improve calculated partial element values for the same number of unknowns, thus improving model stability.

  • 59.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Antonini, Guilio
    University of L’Aquila.
    Orlandi, Antonio
    University of L’Aquila.
    Ruehli, Albert
    Thomas J. Watson Research Center, NY.
    Stability of PEEC models with respect to partial element accuracy2004In: EMC 2004: 2004 IEEE International Symposium on Electromagnetic Compatibility : EMC from DC to daylight : [symposium record] : 09 August-13 [sic], 2004, Silicon Valley, California, Piscataway, NJ: IEEE Communications Society, 2004, p. 271-276Conference paper (Refereed)
    Abstract [en]

    We examine the passivity and stability of quasi-static partial element equivalent circuit (PEEC) models. The impact of inaccuracies in the computed partial element values is considered as a possible source of time domain instabilities. Our analysis shows how existing partial element calculation routines, analytical and numerical, and the use of poor mesh generators can introduce large errors in partial element values. We also show how this affects the passivity and stability of the PEEC model. Theoretical constraints for passivity are derived which depend on accuracy of partial element values. The conditions are verified by performing practical PEEC model analysis.

  • 60.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Antti, Marta-Lena
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Martin-Torres, Javier
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Emami, Reza
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Törlind, Peter
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Innovation and Design.
    Kuhn, Thomas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Nilsson, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Minami, Ichiro
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Öhrwall Rönnbäck, Anna
    Gustafsson, Magnus
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Zorzano Mier, María-Paz
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Milz, Mathias
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Parida, Vinit
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Innovation and Design.
    Behar, Etienne
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Wolf, Veronika
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Dordlofva, Christo
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Innovation and Design.
    Mendaza de Cal, Maria Teresa
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Jamali, Maryam
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Roos, Tobias
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Ottemark, Rikard
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Nieto, Chris
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Soria Salinas, Álvaro Tomás
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Vázquez Martín, Sandra
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Nyberg, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Neikter, Magnus
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Lindwall, Angelica
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Innovation and Design.
    Fakhardji, Wissam
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Projekt: Rymdforskarskolan2015Other (Other (popular science, discussion, etc.))
    Abstract [en]

    The Graduate School of Space Technology

  • 61.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Anttu, Peter
    Parallel implementations of the PEEC Method2007In: 2007 IEEE International Symposium on Electromagnetic Compatibility: workshop and tutorial notes : July 8-13, 2007 Honolulu, Hawaii., Piscataway, NJ: IEEE Communications Society, 2007Conference paper (Refereed)
    Abstract [en]

    This paper presents a parallel implementation of a partial element equivalent circuit (PEEC) based electromagnetic modeling code. The parallelization is based on the GMM++ and ScaLAPACK packages. The parallel PEEC solver was successfully implemented and tested on several high performance computer systems. Large structures containing over 50 000 unknown current and voltage basis functions were successfully analyzed and memory, performance, and speedup results are presented. The numerical examples are both of orthogonal and nonorthogonal type with analysis in the time- and frequencydomain.

  • 62.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Borg, Johan
    Johansson, Jonny
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Lindgren, Per
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    De Lauretis, Maria
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Lindner, Marcus
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Nilsson, Joakim
    Projekt: Frekvensomriktares funktion i beredskapskritiska system2014Other (Other (popular science, discussion, etc.))
    Abstract [sv]

    Vid dödnätstart av produktionsanläggningar och drift av svaga nät eller ö-drift är frekvensomriktare som driver pumpar och fläktar kritiska komponenter. Om frekvensomriktare påverkas av störningar i nätet kan elproduktion kopplas bort och det svaga nätet eller ö-driften kollapsa. Projektet ska studera frekvensomriktare ur ett antal aspekter såsom uppbyggnad, styrning och implementering i syfte att utveckla mer robusta frekvensomriktare och implementering av dessa för att säkerställa drift av svaga nät och ö-drift och minimera ytterligare driftstörningar vid svåra påfrestningar på elnätet.

  • 63.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Enohnyaket, Mathias
    Project: A New Method for Combined Electric and Electromagnetic Modeling of Power Distribution Systems -High frequency models for reactors2011Other (Other (popular science, discussion, etc.))
    Abstract [en]

    The project has the following main objectives.(i) Detail an systematic approach for the generation of equivalent circuit descriptionsfor power components in the high frequency range. Demonstration include time-and frequency- domain analysis of free space coils.(ii) Introduce, evaluate, and develop the PEEC method for combined electric andelectromagnetic (EM) modeling of power components.(iii) Transfer of knowledge from microelectronics- to power engineering- modeling and simulation.

  • 64.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Enohnyaket, Mathias
    Nord, Stefan
    Volvo Technology Corporation, Sverige.
    Gäfvert, Joakim
    Volvo CE, Danmark.
    Projekt: EM Karaktärisering och Modellering av Elektriska Hybriddrivsystem2007Other (Other (popular science, discussion, etc.))
  • 65.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Holm, Magnus
    Delsing, Jerker
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Project: Time domain field calculations using PEEC2011Other (Other (popular science, discussion, etc.))
    Abstract [en]

    Utveckla metodik och verktyg för att simulera och undersöka sambandet mellan mjukvarudesign och elektromagnetiska fält inom inbyggda system. Mjukvaran skall skrivas i språket Timber och elektromagnetiska fält skall simuleras i PEEC. Lämpliga verktyg för att simulera hårdvara skall undersökas och tillämpas, så att ett komplett simuleringsflöde med feedback kan åstadkommas. Utveckla en designparadigm för mjukvara så att oönskade elektromagnetiska effekter och inkompatibiliteter kan undvikas.

  • 66.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Johansson, Jonny
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Lindgren, Per
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Borg, Johan
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Variable-Frequency Drives: Three perspectives2014Conference paper (Refereed)
  • 67.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Lindgren, Tore
    Wickramanayake, Anura
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Project: Improved measurements of mining induced ground deformations using GPS and SAR techniques2011Other (Other (popular science, discussion, etc.))
    Abstract [en]

    The LKAB SAR project is implemented to measure the subsidence and terrain deformation around the Kiruna iron ore mine and in the Kiruna city area. The LKAB SAR project has two components. One is the monitoring component in which MDA (main contractor) provides the SAR deformation maps to LKAB and the second is the technology transfer component in where MDA provides theoretical and practical knowledge to LKAB so that LKAB can produce deformation maps by their own. And Cranfield University and Luleå University of technology will carryout the LKAB SAR research. During the SAR project it is expected to use “DInSAR” and “CTM” techniques to measure the deformations. By using DInSAR and CTM techniques, LKAB can achieve the required accuracy levels during the summer season but it is likely that the quality and quantity of the measurements will largely differ during winter season (due to the thick snow cover). Similarly, areas which have thick forest cover will prevent radar waves reaching the ground and because of that it is likely the quality and quantity of the measurements will decrease in such areas during the mid summer period. Therefore LKAB is planning to carry out a research program to improve the SAR measurements.

  • 68.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Lundgren, Urban
    Luleå University of Technology.
    Nemeth, Robert
    Luleå University of Technology.
    Electromagnetic shielding capabilities of conductive thermoplastic materials and three measurement methods for evaluation2002Report (Other academic)
    Abstract [en]

    This report summarizes the work to compare 12 conductive thermoplastics using three measurement methods. The 12 thermoplastic materials were chosen to observe the influence of variation of base polymer, variation of additives, different mechanical properties and processing and mouldability properties. Test samples were manufactured to be useful in fixtures for far field insertion loss measurements, and to load a coaxial transmission line. Boxes were made to make an enclosure for an electric field source, this arrangement was used for simple application-like near field insertion loss measurements. With all three methods data was obtained in the frequency range from 100 MHz to 1000 MHz for- far field shielding effectiveness- near field shielding effectiveness- complex permeability- complex permittivityResults were obtained showing that variations in the manufacturing process where extra heated thermoplastics or yeast additive was tested, did not improve the shielding efficiency for the particular compounds that was used. The mesurements indicates that a higher amount of additive improves both the near field SE and the far field SE. Measured far field SE is in good agreement with the numerical simulations based on the measured material data.

  • 69.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Monsefi, F.
    Optimization of PEEC based electromagnetic modeling code using grid computing2006In: EMC Europe 2006 Barcelona: [International Symposium on Electromagnetic Compatibility ; September 4 - 8, 2006, Barcelona, Spain] / [ed] Ferran Silva, Barcelona: Universidad Politécnica de Cataluña , 2006Conference paper (Refereed)
  • 70.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Niska, Stefan
    PEEC based formulation suitable for electromagnetic analysis of railway structures2004In: EMC Europe 2004: International Symposium on Electromagnetic Compatibility; September 6 - 10, 2004, Technische Universiteit, Eindhoven, the Netherlands / [ed] A. P. J. van Deursen, Eindhoven: Technische Universiteit Eindhoven, 2004Conference paper (Refereed)
  • 71.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Safavi, Sohrab
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Project: Full-wave electromagnetic modeling with active circuit elements2011Other (Other (popular science, discussion, etc.))
    Abstract [sv]

    Syftet med doktorandprojektet är att utveckla en programvara som kan lösa kretsekvationer för passiva och aktiva komponenter samtidigt som elektromagnetiska problem beskrivna mha ekvivalenta kretsar (Eng. PEEC) löses. Projektet bygger vidare på programvara som tagits fram på EISLAB under de senaste 10 åren och som nu används i flertalet projekt med regionala, nationella och internationella parter. I feb. 2011 har doktoranden en första implementation av en fungerande PEEC-lösare som stödjer aktiva komponenter i form av transistorer (BJTs) och dioder. Nästa steg är att utöka stödet för olika transistormodeller, förna implementationen och inkorporera den i den existerande MultiPEEC-programvaran som utvecklas i ett parallellt projekt.

  • 72.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Wisten, Åke
    Experimental investigation of the current distribution in the couplings of moving trains2009In: IEEE Transactions on Power Delivery, ISSN 0885-8977, E-ISSN 1937-4208, Vol. 24, no 1, p. 311-318Article in journal (Refereed)
    Abstract [en]

    The transport of iron ore from the Swedish mining areas to the harbors is carried out by electric trains. In 2003, there was a dramatic increase in the number of bearings discarded due to electric current corrosion. No evident reason to this increase could be found and a project was initiated measuring electrical currents in engines and couplings as well as position and velocity of the train in an attempt to find countermeasures to the excess currents in the bearings. The RMS-magnitudes of the currents have been recorded and compared for different positions on the train, for different train configurations, and at different driving conditions. The results showed substantial electrical currents going through the couplings and much higher currents in modern trains with 30 tons axle load compared to old trains with 25 tons axle load.

  • 73.
    Ekman, Jonas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Wisten, Åke
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Project: Electromagnetic compatibility issues in the Swedish railway system2011Other (Other (popular science, discussion, etc.))
  • 74.
    Enohnyaket, Mathias
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Analysis of air-core reactors from DC to very high frequencies using PEEC models2009In: IEEE Transactions on Power Delivery, ISSN 0885-8977, E-ISSN 1937-4208, Vol. 24, no 2, p. 719-729Article in journal (Refereed)
    Abstract [en]

    Faced with the challenges of increasing operational frequencies and switching rates of modern power electronics devices used in power systems, there is need for high frequency models (up to a few megahertz) for power components like reactors, capacitors banks and transformers. This paper presents the application of PEEC theory forthe creation of high frequency, electromagnetic models for air-core reactors. The electromagnetic field couplings are separated in mutual partial inductances and mutual coefficients of potential giving a correct solution from DC to a maximum frequency determined by the meshing. The PEEC models are validated by comparing simulation results, for both time and frequency domain analysis, against measurements and other established modeling methods, and show good agreement. The model created by PEEC theory, could be helpful in the design and diagnostics of air-core reactors and other power system components.

  • 75. Enohnyaket, Mathias
    et al.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    High frequency models for air-core reactors using 3D equivalent circuit theory2006In: Proceedings of Nordic Distribution and Asset Management Conference: NORDAC 2006, 2006Conference paper (Refereed)
    Abstract [en]

    This paper presents recent advancements in creating high frequency model for air-core reactors using partial element equivalent circuit (PEEC) theory. By meshing each turn into rectangular bars, PEEC theory can be applied and the reactors can be studied in detail. Measurements results are compared to PEEC model results for the frequency domain while time domain results are presented solely for the models. It is shown that the time complexity for modeling a realistic reactor is acceptable on a regular workstation.

  • 76. Enohnyaket, Mathias
    et al.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    PEEC models for air-core reactors modeling skin and proximity effects2007In: 2007 IEEE Power Electronics Specialists Conference: [PESC 07] ; Orlando, Florida, 17 - 21 June 2007, Piscataway, NJ: IEEE Communications Society, 2007, p. 3034-3038Conference paper (Refereed)
    Abstract [en]

    This paper presents a partial element equivalent circuit (PEEC) model for air-core reactors modeling skin and proximity effects at higher frequencies using the volume filament approach. Modeling results are compared to measurements in both time domain and frequency domain, and show good agreement.

  • 77. Enohnyaket, Mathias
    et al.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Three dimensional high frequency models for air-core reactors based on partial element equivalent circuit theory2006In: EMC Europe 2006 Barcelona: [International Symposium on Electromagnetic Compatibility ; September 4 - 8, 2006, Barcelona, Spain] / [ed] Ferran Silva, Barcelona: Universidad Politécnica de Cataluña , 2006Conference paper (Refereed)
  • 78.
    Enohnyaket, Mathias
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering.
    Wisten, Åke
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Electromagnetic fields from air-core reactors using equivalent circuit theory2007In: EMB07 - the fourth Swedish conference on computational electromagnetics: methods and applications / [ed] Anders Karlsson; Gerhard Kristensson; Daniel Sjöberg, 2007, p. 69-74Conference paper (Refereed)
  • 79.
    Hartman, Andreas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Antonini, Giulio
    Department of Electrical Engineering, University of L’Aquila.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    De Lauretis, Maria
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Bandlimited Distortionless Material Design by an Approximation of the Heaviside Condition2019In: IEEE transactions on electromagnetic compatibility (Print), ISSN 0018-9375, E-ISSN 1558-187XArticle in journal (Refereed)
    Abstract [en]

    The distortionless propagation of signals in a medium offers a way to preserve the signal integrity. There exists a condition for distortionless propagation on a transmission line known as the Heaviside condition. This paper proposes the use of the Heaviside condition to characterize and design magneto-dielectric materials that provide distortionless propagation in a specified finite frequency band. Plane wave propagation in a magneto-dielectric material is modeled by a transmission line model, thereby assuming transverse electromagnetic mode propagation. Then, the Heaviside condition is employed to derive the frequency-dependent permittivity and permeability functions of the material in rational form, so they satisfy the condition in a specified frequency interval. A procedure to design such materials is described. A numerical example of the design process is provided and an illustration of the effectiveness of modeled material in fulfilling the Heaviside condition in a specified frequency interval both in the time and frequency domains is given, indicating the validity of the approximation. The design procedure is as such a suitable preliminary design guide for deriving a realizable description of a magnetodielectric, exhibiting the distortionless property in the desired frequency interval, with certain specified requirements put on the loss, or the permeability and permittivity values satisfied. The obtained results may initiate further investigations into the bandwidth restrictions of the approximation, on closed-form design solutions, and the practical realization of such materials.

  • 80.
    Hartman, Andreas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Antonini, Giulio
    Department of Electrical Engineering, University of L’Aquila.
    Romano, Daniele
    Dipartimento di Ingegneria Industriale e dell'Informazione e di Economia, Università degli Studi dell'Aquila.
    A Descriptor Form Implementation of PEEC Models Incorporating Dispersive and Lossy Dielectrics2016In: 2016 IEEE International Symposium on Electromagnetic Compatibility (EMC): Otawa, Canada, 25-29 July 2016, Piscataway, NJ: IEEE Computer Society, 2016, p. 206-211, article id 7571645Conference paper (Refereed)
    Abstract [en]

    With rising frequencies involved in electronics, losses and dispersion exhibited by dielectrics become important to consider in electromagnetic modeling. The Partial Element Equivalent Circuit (PEEC) method is suitable for a mixed electromagnetic and circuit setting, forming equivalent circuits that can be interconnected with circuit elements. In this paper, a descriptor form representation of PEEC models incorporatingdispersive and lossy dielectrics is developed. By representing the electrical permittivity with a Debye-Lorentz model equivalent circuits can be synthesized. The synthesized circuits for the permittivity are included in the PEEC equations by formulating the circuit equations for the additional circuit unknowns. This yields an input/output formulation that can handle an arbitrary number of finite dielectrics and be integrated by any kind of integration scheme. Furthermore, it offers a straightforward way to incorporate lossy and dispersive dielectrics into a PEEC solver compared to using recursive convolution. The proposed descriptor form representation is tested for a setup consisting of three microstrips over a ground plane, separated by a dielectric substrate. Both the ideal and the lossy and dispersive case are tested and compared. Furthermore, the proposed formulation is verified against an existing implementation in the frequency domain. Good agreement between the proposed formulation andthe existing frequency-domain PEEC formulation is obtained.

  • 81.
    Hartman, Andreas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Lang, Defeng
    SKF Research & Technology Development, Nieuwegein, The Netherlands.
    Romano, Daniele
    E dell'Informazione e di Economia, Università degli Studi dell’ Aquila, Dipartimento di Ingegneria Industriale, L’ Aquila, Italy.
    Antonini, Giulio
    E dell'Informazione e di Economia, Università degli Studi dell’ Aquila, Dipartimento di Ingegneria Industriale, L’ Aquila, Italy.
    PEEC Models of Printed Antennas in Condition Monitoring Applications Covered by Dielectrics with Temperature-Dependent Permittivity2018In: 2018 International Symposium on Electromagnetic Compatibility (EMC EUROPE), Piscataway, NJ: IEEE, 2018, p. 343-348, article id 8485032Conference paper (Refereed)
    Abstract [en]

    In wireless condition monitoring systems the antenna serves as a critical part of the data transmission link. A condition monitoring application usually pose a challenging environment for an antenna system, as they are often found in harsh machine environments. As conventional antennas usually are designed for free-space operation and for some design temperature range, the presence of additional materials and their temperature variation are commonly not accounted for. In this paper an attempt to highlight the impact of materials' temperature-dependence, in their electrical properties, on printed antenna characteristics is presented. Partial element equivalent circuit models of a common printed antenna design are developed. By incorporating temperature-dependent permittivity models of pure water, and a mixture of an industrial lubricant and water, the impact on the antenna's resonant behavior is demonstrated. The numerical examples highlight that the temperature variation in the permittivity of materials surrounding the printed antenna may impact the antenna characteristics enough to be considered in the design, if a degradation in performance is not an option.

  • 82.
    Hartman, Andreas
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Romano, Daniele
    UAq EMC Laboratory, Dipartimento di Ingegneria Industriale e dell’Informazione e di Economia, Università degli Studi dell’Aquila.
    Antonini, Giulio
    UAq EMC Laboratory, Dipartimento di Ingegneria Industriale e dell’Informazione e di Economia, Università degli Studi dell’Aquila.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Partial Element Equivalent Circuit Models of Three-Dimensional Geometries Including Anisotropic Dielectrics2018In: IEEE transactions on electromagnetic compatibility (Print), ISSN 0018-9375, E-ISSN 1558-187X, Vol. 60, no 3, p. 696-704Article in journal (Refereed)
    Abstract [en]

    During recent years anisotropic materials have received an increasing interest and found important applications in the field of shielding and antennas. The anisotropy may be due to intrinsic properties, or as a consequence of mixing. Intentionally or not, the anisotropy impacts the electromagnetic (EM) behavior of a system. Therefore, it is desirable to be able to incorporate the anisotropic effects in an EM model, to allow design tasks and analysis. In this paper, the partial element equivalent circuit (PEEC) formulation is extended to handle nondispersive linear anisotropic dielectrics. The anisotropic dielectric PEEC cell is derived and the resulting PEEC equations are developed into a descriptor system form, which is well suited for implementation in SPICE-like solvers, and for reduction by model-order reduction techniques. A verification of the model is given by a numerical example of a patch antenna situated on an anisotropic substrate and the results are in good agreement with a finite-difference time-domain implementation. The proposed PEEC model is of interest for further work, i.e., in the modeling of setups involving mixtures of materials, with an orientational alignment, and engineered materials, encountered in different EM compatibility applications.

  • 83.
    Johansson, Jonny
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Borg, Johan
    Larsmark, Mikael
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Lindgren, Tore
    Lundberg Nordenvaad, Magnus
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Johansson, Gustav
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Ståbis, Joel
    Sverige.
    Project: EISCAT 3D2007Other (Other (popular science, discussion, etc.))
  • 84.
    Kovačević-Badstübner, Ivana
    et al.
    Advanced Power Semiconductor Laboratory, ETH Zurich, Zurich.
    Grossner, Ulrike
    Advanced Power Semiconductor Laboratory, ETH Zurich, Zurich.
    Romano, Daniele
    University of L'Aquila, L'Aquila, Italy.
    Antonini, Giulio
    University of L'Aquila, L'Aquila, Italy.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    A more accurate electromagnetic modeling of WBG power modules2018In: Proceedings of the International Symposium on Power Semiconductor Devices and ICs, Institute of Electrical and Electronics Engineers (IEEE), 2018, p. 260-263Conference paper (Refereed)
    Abstract [en]

    A major requirement for further development of wide-band gap (WBG) power devices and their applications is the optimization of packages and PCB layouts to enable fast-switching capabilities. Electromagnetic modelling allows the prediction of parasitic inductances, capacitances, and resistances of the current paths within power modules, which cannot be easily approached in measurements. As a result, electromagnetic-circuit-coupled modeling enables the optimization of package layouts and interconnections before manufacturing actual power modules. The accuracy and limitations of present numerical techniques for three-dimensional (3D) electromagnetic modeling of power modules is still neither well understood nor verified. This paper presents the extraction of parasitics of power semiconductor packages using two electromagnetic modelling approaches. The first approach is based on a well-established 3D electromagnetic quasi-static solver, ANSYS Q3D Extractor. For the second approach, a numerical solver based on the Partial Element Equivalent Circuit (PEEC) method is developed and assessed in terms of modelling accuracy required by fast switching WBG-based power converters. The PEEC method is presented as a promising numerical technique, which can potentially be used to overcome the limitations of the EM modeling based on the ANSYS Q3D Extractor.

  • 85.
    Kovačević-Badstübner, Ivana
    et al.
    Advanced Power Semiconductor Laboratory, ETH Zurich, Switzerland.
    Romano, Daniele
    University of L’Aquila, L’Aquila, Italy.
    Antonini, Giulio
    University of L’Aquila, L’Aquila, Italy.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Grossner, Ulrike
    Advanced Power Semiconductor Laboratory, ETH Zurich, Switzerland.
    Electromagnetic Modeling Approaches Towards Virtual Prototyping of WBG Power Electronics2018In: 2018 International Power Electronics Conference (IPEC-Niigata 2018 -ECCE Asia), Piscataway, NJ: IEEE, 2018, p. 3588-3595, article id 8507365Conference paper (Refereed)
    Abstract [en]

    High frequency power electronics utilizing wide-band gap semiconductor devices imposes more stringent requirements for highly accurate extraction of parasitics of power electronics systems in a wide frequency range. This paper presents the state-of-the-art modeling approaches used to predict the electromagnetic behavior of power electronic systems and components in terms of accuracy and computational cost. The potential of the Partial Element Equivalent Circuit (PEEC) technique for virtual prototyping of power electronic systems is assessed. The main advantage of this numerical technique is its capability for direct coupling between the circuit and electromagnetic domains provided by the PEEC meshing of three-dimensional geometries in partial elements. The aim of this paper is to provide a more comprehensive understanding of PEEC-based modeling for power electronics packaging.

  • 86.
    Kvarnström, Björn
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Lindgren, Tore
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Monte Carlo simulation of an radio frequency identification system with moving transponders using the partial element equivalent circuit method2010In: IET Microwaves, Antennas & Propagation, ISSN 1751-8725, E-ISSN 1751-8733, Vol. 4, no 12, p. 2069-2076Article in journal (Refereed)
    Abstract [en]

    When designing an radio frequency identification system it is important to take both the position and the movement of the transponders into account. In this study, a simulation method that enables the description of a complete RFID system including moving and rotating transponders as well as a complex, industrial environment is presented. By using the partial element equivalent circuit method to calculate the magnetic field generated by the reader antenna and describing the transponders using a magnetic dipole, it is possible to use the Monte Carlo method to describe the dynamic behaviour of the complete system. The method is used in this study to describe the difference in performance between two different reader antennas and these results are also compared to measurements of similar systems operating in an industrial environment. The difference in performance between the two systems is similar in both the simulations and the measurements. A small discrepancy was seen between the results from the simulations and the measurements which is for the most part because of the limited read rate of the RFID systems used in the measurements.

  • 87.
    Lindgren, Tore
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Design and evaluation of RFID systems using the partial element equivalent circuit method2008In: Proceedings of the International Symposium on Antenna and Propagation: ISAP 2008, Chinese Microwave Association , 2008Conference paper (Refereed)
    Abstract [en]

    Systems based on radio frequency identification (RFID) techniques are finding new markets and uses. For maximal readability, RFID-systems have to be tailored to its specific environment. In this paper, the partial element equivalent circuit (PEEC) method is used to analyze an RFID-system with reader, tag, and additional electronic circuitry. The results show how the method can be used to match antennas with discrete, external components and study the backscattered energy from the tag. The simulations are very fast which allows for studying multiple locations of the tag in order to tailor the RFID-system.

  • 88.
    Lindgren, Tore
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Ekman, Jonas
    Performance of a Yagi antenna during snowfall2008In: Proceedings of the International Symposium on Antenna and Propagation: ISAP 2008, Chinese Microwave Association , 2008Conference paper (Refereed)
    Abstract [en]

    Precipitation in the form of snow could severely degrade the performance of the planned EISCAT_3D radar antenna array. In this paper the performance of the antenna elements, crossed yagi antennas, is studied using both simulations and measurements. The results shows that during snowfall the performance of the antenna is degraded, and under severe conditions the antenna becomes non-operational. To guarantee operability of the system, the effect of snow cover should be taken into account when designing the final antenna.

  • 89.
    Lindgren, Tore
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Ekman, Jonas
    Backén, Staffan
    A measurement system for the complex far-field of physically large antenna arrays under noisy conditions utilizing the equivalent electric current method2010In: IEEE Transactions on Antennas and Propagation, ISSN 0018-926X, E-ISSN 1558-2221, Vol. 58, no 10, p. 3205-3211Article in journal (Refereed)
    Abstract [en]

    Precipitation in the form of snow or rain could severely degrade the performance of large antenna arrays, in particular if knowledge about the beam shape and pointing direction in absolute numbers is necessary. In this paper, a method of estimating the far-field of each individual antenna element using the equivalent electric current approach is presented. Both a least squares estimator and a Kalman filter was used to solve the resulting system of equation and their performance was compared. Simulation results shows that the estimated far-field for one antenna element is very accurate if there is no noise on the signal. During noisier conditions the Kalman filter gives less noisy results while the systematic errors are slightly larger compared to the least squares estimator.

  • 90.
    Lombardi, Luigi
    et al.
    UAq EMC Laboratory, Dipartimento di Ingegneria Industriale e dell'Informazione e di Economia, Università degli Studi dell'Aquila, Italy.
    Antonini, Giulio
    UAq EMC Laboratory, Dipartimento di Ingegneria Industriale e dell'Informazione e di Economia, Università degli Studi dell'Aquila, Italy.
    De Lauretis, Maria
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Jonas, Ekman
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    On the Distortionless Propagation in Multiconductor Transmission Lines2018In: IEEE Transactions on Components, Packaging, and Manufacturing Technology, ISSN 2156-3950, E-ISSN 2156-3985, Vol. 8, no 4, p. 538-545Article in journal (Refereed)
    Abstract [en]

    In this paper, we investigate the distortionless conditions for multiconductor transmission lines (MTLs) with frequency-independent per-unit-length (p.u.l.) parameters. In fact, the well-known distortionless Heaviside condition is valid only for single-conductor transmission lines. The MTL is modeled using the delayed Green's-function-based method recently proposed by the authors. In this method, the impedance matrix is described in terms of a rational part, which accounts for the low-frequency behavior, and a hyperbolic part, which determines the high-frequency response of the MTL. We find that the hyperbolic part is already distortionless at high frequency and that this property can be used to identify the p.u.l. parameters of the distortionless lossy MTL associated with the original line. To serve this purpose, the line is decoupled using a frequency-independent modal decomposition. The Heaviside condition can be enforced in the modal domain on each of the single-conductor decoupled lines. The features of the distortionless lines in the modal domain are preserved in the physical domain as a consequence of the real-valued similarity transform. The numerical results demonstrate that the new line completely characterizes the distortionless propagation of a generic MTL with frequency-independent p.u.l. parameters. The proposed formulation could be used in the optimization design process by enforcing the distortionless condition along with other design constraints.

  • 91.
    Lundgren, U
    et al.
    Omicron Ceti AB.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Delsing, Jerker
    Shielding effectiveness data on commercial thermoplastic materials2006In: IEEE transactions on electromagnetic compatibility (Print), ISSN 0018-9375, E-ISSN 1558-187X, Vol. 48, no 4, p. 766-773Article in journal (Refereed)
    Abstract [en]

    Ten different commercially available conductive thermoplastic materials have been tested for near- and far-field shielding effectiveness (SE). Far-field SE was tested using a modified standard measurement technique to provide results comparable with the company-provided data. Further, housings of different thermoplastic materials were constructed and equipped with an electromagnetic interference (EMI) source to model a realistic near-field SE situation. The SE data up to 1 GHz is presented. Conductive thermoplastic materials with fillings of stainless steel fibers and nickel-coated carbon fibers were the two materials that offer the best far-field shielding performance. For the near-field shielding, two materials with filling of stainless steel fibers were the best performing ones. A thermoplastic with polycarbonate (PC) base and stainless steel content of 1.5 vol% showed the best combined far- and near-field shielding results.

  • 92.
    Lundgren, Urban
    et al.
    Luleå tekniska universitet.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Analysis of printed antenna structures using the partial element equivalent circuit (PEEC) method2001In: Conference proceedings : EMB 01: electromagnetic computations - methods and applications / [ed] Fredrik Edelvik, Uppsala universitet, 2001Conference paper (Refereed)
    Abstract [en]

    The partial element equivalent circuit (PEEC) method is a electromagnetic simulation technique suitable for mixed circuit and field problems. The technique is numerically equivalent to a method of moments solution using Galerkin solution. In this paper, the PEEC method is illustrated and applied to printed antenna structures where measurements are compared to simulations and analytical solutions. The possibility to use simplified PEEC models to decrease computation time is discussed with illustrative examples.

  • 93.
    Lundgren, Urban
    et al.
    Luleå tekniska universitet.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Delsing, Jerker
    Characterization of conductive thermoplastic composite materials using multiple measurement methods2002In: Symposium record - EMC Europe 2002, International Symposium on Electromagnetic Compatibility: September 9 - 13, Sorrento, Italy, Sorrento, 2002Conference paper (Refereed)
  • 94.
    Miroshnikova, Elena
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mathematical Science.
    Antonini, Giulio
    University of L'Aquila (Italy).
    De Lauretis, Maria
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    On the Passivity of the Delay-Rational Green’s-Function-Based Model for Transmission Lines2017In: Analysis, Probability, Applications, and Computation: Proceedings of the 11th ISAAC Congress, Växjö (Sweden) 2017 / [ed] Karl‐Olof Lindahl, Torsten Lindström, Luigi G. Rodino, Joachim Toft, Patrik Wahlberg, Springer, 2017, p. 71-81Conference paper (Refereed)
    Abstract [en]

    In this paper, we study the delay-rational Green’s-function-based (DeRaG) model for transmission lines. This model is described in terms of impedance representation and it contains a rational and a hyperbolic part. The crucial property of transmission lines models is to be passive. The passivity of the rational part has been studied by the authors in a previous work. Here, we extend the results to the rational part of the DeRaG model. Moreover, we prove the passivity of the hyperbolic part.

  • 95.
    Monsefi, Faid
    et al.
    Luleå tekniska universitet.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Antenna analysis using PEEC and the complex image method2006In: Proceedings of the Nordic Antenna Symposium, Försvarets materielverk , 2006Conference paper (Refereed)
    Abstract [en]

    The PEEC method is a 3D, full wave modeling method suitable for combined electromagnetic and circuit analysis. In the PEEC method, the integral equation is interpreted as Kirchoff's voltage law applied to a basic PEEC cell which results in a complete circuit solution for 3D geometries. The equivalent circuit formulation allows for additional SPICE-type circuit elements to easily be included. Further, the models and the analysis apply to both the time and the frequency domain. The circuit equations resulting from the PEEC model are easily constructed using a condensed modified loop analysis (MLA) or modified nodal analysis (MNA) formulation. In the MNA formulation, the volume cell currents and the node potentials are solved simultaneously for the discretized structure. To obtain field variables, post-processing of circuit variables is necessary.In this paper, it is shown that how the PEEC method is applied to model antenna characteristics, including input impedance and radiation diagrams, by use of the appropriate Green's function in the calculation of partial elements. The electric field for a layered medium is a three-dimensional convolution between the dyadic Green's function and the source current density. This convolution integral is strongly singular which makes the numerical integration very time-consuming. Solving this type of integral is one of the topics within electromagnetism. By using the complex image method (CIM), the appropriate Green's function is obtained much easier in terms of, for instance, spherical wave components where the real and imaginary sources are expressed in a series of summations. As a result, the time complexity for computing coefficients of potential Pij and partial inductances Lpij within PEEC is improved. The appropriate Green's functions, obtained in this process, will also be used to determine the volume cell currents I and node voltages V in a structure.

  • 96.
    Muesing, Andreas
    et al.
    ETH Zurich.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Kolar, Johann W.
    ETH Zurich.
    Efficient calculation of non-orthogonal partial elements for the PEEC method2008In: Proceedings of the 13th Biennial IEEE Conference on Electromagnetic Field Computation: CEFC '08, 2008Conference paper (Refereed)
    Abstract [en]

    For various electrical interconnect and EMC problems, the Partial Element Equivalent Circuit (PEEC) method has proven to be a valid and fast solution method of the electrical field integral equation in the time as well as the frequency domain. Therefore, PEEC has become a multi-purpose full-wave method, especially suited for the solution of combined circuit and EM problems, as found, for instance, on printed circuit board layouts, power electronics devices or EMC filters. Recent research introduced various extensions to the basic PEEC approach, for example a nonorthogonal cell geometry formulation. This work presents a fast, flexible and accurate computational method for determining the matrix entries of partial inductances and the coefficients of potential for general non-orthogonal PEEC cell geometries. The presented computation method utilizes analytical filament formulas to reduce the integration order and therefore to reduce computation time. The validity, accuracy and speed of the proposed method is compared with a standard integration routine on example cell geometries where the numeric results of the new method show improved accuracy, coming along with reduced computation time.

  • 97.
    Muesing, Andreas
    et al.
    ETH Zurich.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Kolar, Johann W.
    ETH Zurich.
    Efficient calculation of non-orthogonal partial elements for the PEEC method2009In: IEEE transactions on magnetics, ISSN 0018-9464, E-ISSN 1941-0069, Vol. 45, no 3, p. 1140-1143Article in journal (Refereed)
    Abstract [en]

    For various electrical interconnect and EMC problems, the partial element equivalent circuit (PEEC) method has proven to be a valid and fast solution method of the electrical field integral equation in the time as well as the frequency domain. Therefore, PEEC has become a multipurpose full-wave method, especially suited for the solution of combined circuit and EM problems, as found, for instance, on printed circuit board layouts, power electronics devices or EMC filters. Recent research introduced various extensions to the basic PEEC approach, for example a non-orthogonal cell geometry formulation. This paper presents a fast, flexible and accurate computational method for determining the matrix entries of partial inductances and the coefficients of potential for general non-orthogonal PEEC cell geometries. The presented computation method utilizes analytical filament formulas to reduce the integration order and therefore to reduce computation time. The validity, accuracy, and speed of the proposed method is compared with a standard integration routine on example cell geometries where the numeric results of the new method show improved accuracy, coming along with reduced computation time.

  • 98.
    Mäkitaavola, Karola
    et al.
    LKAB, Luossavaara Kiirunavaara Aktiebolag.
    Stöckel, Britt-Mari
    LKAB, Luossavaara Kiirunavaara Aktiebolag.
    Sjöberg, Jonny
    Itasca Consultants AB.
    Hobbs, Stephen
    Cranfield University.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Henschel, Michael
    MDA Geospatial Serv, Ottawa.
    Wickramanayake, Aurora
    Application of InSAR for monitoring deformations at the Kiirunavaara Mine2016In: Operational and Environmental Mine Health and Safety Practice and Innovation / [ed] Mitri, H; Shnorhokian, S; Kumral, M; Sasmito, A; Sainoki, A, Montreal: McGill University. , 2016, p. 133-139Conference paper (Refereed)
    Abstract [en]

    An integral part of sublevel cave underground mining is the associated caving of the surrounding host rock. This causes mining-induced ground surface deformations on both the hangingwall and footwall side of the orebody. The municipality of Kiruna, in northern Sweden, is located in close proximity to the LKAB Kiirunavaara mine and is thus unavoidably affected by the mining activities. To be able to plan for an urban transformation, as the effects of mining approach the city infrastructure, it is necessary to monitor the ground deformations on a regular basis. Historically, GPS-monitoring has been used, with an extensive network of measurement hubs in place. New techniques for monitoring ground deformations are, however, constantly evaluated. As part of this process, LKAB has conducted a five-year research and development project on deformation measurements using radar satellites and the InSAR technology. The project has included a monitoring component and a research-and technology transfer component. The overall findings of the monitoring program, and the associated research and development work are presented. Particular emphasis is put on achieved accuracy and the implications for the ability to reliably monitor the progressing deformations toward the municipality and existing infrastructure. Lessons learnt from the conducted work are presented, followed by recommendations on future use of InSAR for this type of application

  • 99. Niska, Stefan
    et al.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Analysis and modeling of EMC problems in railway detector systems2004In: EMC Europe 2004 :: International Symposium on Electromagnetic Compatibility; September 6 - 10, 2004, Technische Universiteit, Eindhoven, the Netherlands / [ed] A. P. J. van Deursen, Eindhoven: Technische Universiteit Eindhoven, 2004Conference paper (Refereed)
  • 100. Niska, Stefan
    et al.
    Ekman, Jonas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Combining 2D transmission line models with 3D PEEC models2004In: Proc. of EMB04, Gothenburg, Sweden, Oct., 2004., 2004Conference paper (Refereed)
123 51 - 100 of 121
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