Pub Date : 2007-11-27DOI: 10.1109/EMCZUR.2007.4388285
C. Collins
Numerical field calculations considering the geometry and electromagnetic (EM) properties of the human body are used increasingly for engineering and safety assurance in magnetic resonance imaging (MRI). This can include calculations of static magnetic (B0) fields, switched audio-frequency (gradient) fields, and pulsed radiofrequency (B1) fields. Relation of field calculation results to the MRI experiment can require significant understanding of both basic MRI physics and EM field safety. Here an introductory review explaining what entities of field calculations are valuable for MRI is presented.
{"title":"EM Modeling and MR: overview and safety topics","authors":"C. Collins","doi":"10.1109/EMCZUR.2007.4388285","DOIUrl":"https://doi.org/10.1109/EMCZUR.2007.4388285","url":null,"abstract":"Numerical field calculations considering the geometry and electromagnetic (EM) properties of the human body are used increasingly for engineering and safety assurance in magnetic resonance imaging (MRI). This can include calculations of static magnetic (B0) fields, switched audio-frequency (gradient) fields, and pulsed radiofrequency (B1) fields. Relation of field calculation results to the MRI experiment can require significant understanding of both basic MRI physics and EM field safety. Here an introductory review explaining what entities of field calculations are valuable for MRI is presented.","PeriodicalId":397061,"journal":{"name":"2007 18th International Zurich Symposium on Electromagnetic Compatibility","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130876223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-11-27DOI: 10.1109/EMCZUR.2007.4388258
I. Metwally, F. Heidler
Surge protective devices (SPDs) are installed at the boundaries of lightning protection zones (LPZs) to damp the surges to the protection level of the SPD. If the circuit between the SPD and the apparatus to be protected is too long, the propagation of the surges leads to oscillation phenomenon. In this case, the overvoltage can be increased at the apparatus terminals. The increase is taken into account by an enhancement factor which gives the ratio of the maximum overvoltage at the apparatus terminals to the SPD protective level. According to IEC 62305-4, the maximum enhancement factor is considered to be equal to two in the worst case of open-circuit condition. The objective of the present paper is to check this relation for equipment connected to low-voltage (LV) power system. The LV power system is considered as TN-S system with different routings in a three-storey building. The terminals of apparatus are substituted by different loads. All Maxwell’s equations are solved by the method of moments and the voltage is calculated at the apparatus terminals. The SPD itself is simulated by a voltage source at the ground floor of the building. The results reveal that the apparatus terminal voltage may overshoot the SPD protection level by a factor of 3.
{"title":"Influence of line routing and terminations on transient overvoltages in LV power installations","authors":"I. Metwally, F. Heidler","doi":"10.1109/EMCZUR.2007.4388258","DOIUrl":"https://doi.org/10.1109/EMCZUR.2007.4388258","url":null,"abstract":"Surge protective devices (SPDs) are installed at the boundaries of lightning protection zones (LPZs) to damp the surges to the protection level of the SPD. If the circuit between the SPD and the apparatus to be protected is too long, the propagation of the surges leads to oscillation phenomenon. In this case, the overvoltage can be increased at the apparatus terminals. The increase is taken into account by an enhancement factor which gives the ratio of the maximum overvoltage at the apparatus terminals to the SPD protective level. According to IEC 62305-4, the maximum enhancement factor is considered to be equal to two in the worst case of open-circuit condition. The objective of the present paper is to check this relation for equipment connected to low-voltage (LV) power system. The LV power system is considered as TN-S system with different routings in a three-storey building. The terminals of apparatus are substituted by different loads. All Maxwell’s equations are solved by the method of moments and the voltage is calculated at the apparatus terminals. The SPD itself is simulated by a voltage source at the ground floor of the building. The results reveal that the apparatus terminal voltage may overshoot the SPD protection level by a factor of 3.","PeriodicalId":397061,"journal":{"name":"2007 18th International Zurich Symposium on Electromagnetic Compatibility","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115751575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-11-27DOI: 10.1109/EMCZUR.2007.4388193
E. Hoene, A. Lissner, S. Guttowski
The performance of EMI filters is severely influenced by the placement of passive components. This paper introduces a method to predict these effects and demonstrates its potential on a DC/DC-Converter for automotive applications. Design rules are derived for favourable placement of several types of passive components.
{"title":"Prediction of EMI behaviour in terms of passive component placement","authors":"E. Hoene, A. Lissner, S. Guttowski","doi":"10.1109/EMCZUR.2007.4388193","DOIUrl":"https://doi.org/10.1109/EMCZUR.2007.4388193","url":null,"abstract":"The performance of EMI filters is severely influenced by the placement of passive components. This paper introduces a method to predict these effects and demonstrates its potential on a DC/DC-Converter for automotive applications. Design rules are derived for favourable placement of several types of passive components.","PeriodicalId":397061,"journal":{"name":"2007 18th International Zurich Symposium on Electromagnetic Compatibility","volume":"56 61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124320189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-11-27DOI: 10.1109/EMCZUR.2007.4388299
Stephane Coets, V. Beauvois
This paper deals with a novel indirect measurement method using a “virtual” LISN to get normalised, reproducible and accurate results. According to the CISPR 16-2-1 standard [1], in the low frequency range, conducted emission measurements should be performed on power supply lines either with a Line Impedance Stabilized Network (LISN) or with a passive voltage probe. However both methods have drawbacks in terms of accuracy, feasibility, etc. This paper briefly compares different direct alternative methods of conductive emission measurement in case of high-power equipements. Furthermore, a new indirect method of measurement based on the research of a simple and stable EUT model and using a “virtual” LISN is presented.
{"title":"An Indirect Alternative Method of Measurement for Conducted Emissions of High-Power Equipments","authors":"Stephane Coets, V. Beauvois","doi":"10.1109/EMCZUR.2007.4388299","DOIUrl":"https://doi.org/10.1109/EMCZUR.2007.4388299","url":null,"abstract":"This paper deals with a novel indirect measurement method using a “virtual” LISN to get normalised, reproducible and accurate results. According to the CISPR 16-2-1 standard [1], in the low frequency range, conducted emission measurements should be performed on power supply lines either with a Line Impedance Stabilized Network (LISN) or with a passive voltage probe. However both methods have drawbacks in terms of accuracy, feasibility, etc. This paper briefly compares different direct alternative methods of conductive emission measurement in case of high-power equipements. Furthermore, a new indirect method of measurement based on the research of a simple and stable EUT model and using a “virtual” LISN is presented.","PeriodicalId":397061,"journal":{"name":"2007 18th International Zurich Symposium on Electromagnetic Compatibility","volume":"365 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125829576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-11-27DOI: 10.1109/EMCZUR.2007.4388210
Phumin Kirawanich, James E. Thompson, N. Islam
This paper introduces a new topological scheme for electromagnetic compatibility simulation for aperture-system interactions. By introducing modular scattering junctions as wave propagation paths, this simulation method substitutes the multi-step computational process presented earlier by a single simulation step without ignoring backscattering interactions. The method also allows for modifications in the sub-structural level without simulating the entire system. The simulations involve transmission line matrix compaction, finite-difference timedomain method, and reciprocity theorem to create different junctions. The numerical results generated by this concept have been validated through experimental results and there is a good agreement between the simulated and experimental data.
{"title":"A modular junction topological approach to system interaction problems: simulation and validation","authors":"Phumin Kirawanich, James E. Thompson, N. Islam","doi":"10.1109/EMCZUR.2007.4388210","DOIUrl":"https://doi.org/10.1109/EMCZUR.2007.4388210","url":null,"abstract":"This paper introduces a new topological scheme for electromagnetic compatibility simulation for aperture-system interactions. By introducing modular scattering junctions as wave propagation paths, this simulation method substitutes the multi-step computational process presented earlier by a single simulation step without ignoring backscattering interactions. The method also allows for modifications in the sub-structural level without simulating the entire system. The simulations involve transmission line matrix compaction, finite-difference timedomain method, and reciprocity theorem to create different junctions. The numerical results generated by this concept have been validated through experimental results and there is a good agreement between the simulated and experimental data.","PeriodicalId":397061,"journal":{"name":"2007 18th International Zurich Symposium on Electromagnetic Compatibility","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128114529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-11-27DOI: 10.1109/EMCZUR.2007.4388259
H. Karami, R. Moini, S. Sadeghi
A model-based parameter estimation (MBPE) technique is proposed to reduce the number of frequency-domain calculation points required for the evaluation of space-time current distribution along a lightning return stroke channel. In applying this technique to a rational function model for the channel current distribution, a uniform-like and a two-stage adaptive sampling strategies are investigated. To obtain height dependent current distribution at required frequency sampling points, the antenna theory model of lightning channel is used. The proposed technique is validated against the conventional inverse fast Fourier transform algorithm which uses a method of moment solution for all frequencies within the channel base current spectrum. It is shown that considerable computation efficiency is achieved in terms of CPU time without losing accuracy.
{"title":"A model-based parameter estimation of current distribution along lightning return stroke channel","authors":"H. Karami, R. Moini, S. Sadeghi","doi":"10.1109/EMCZUR.2007.4388259","DOIUrl":"https://doi.org/10.1109/EMCZUR.2007.4388259","url":null,"abstract":"A model-based parameter estimation (MBPE) technique is proposed to reduce the number of frequency-domain calculation points required for the evaluation of space-time current distribution along a lightning return stroke channel. In applying this technique to a rational function model for the channel current distribution, a uniform-like and a two-stage adaptive sampling strategies are investigated. To obtain height dependent current distribution at required frequency sampling points, the antenna theory model of lightning channel is used. The proposed technique is validated against the conventional inverse fast Fourier transform algorithm which uses a method of moment solution for all frequencies within the channel base current spectrum. It is shown that considerable computation efficiency is achieved in terms of CPU time without losing accuracy.","PeriodicalId":397061,"journal":{"name":"2007 18th International Zurich Symposium on Electromagnetic Compatibility","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114243151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-11-27DOI: 10.1109/EMCZUR.2007.4388233
G. Antonini, M. Cocchini, A. Dominicis, M. Italiani, A. Orlandi
The presence of a lightning protection system for mobile radar structure requires a detailed study of the electromagnetic effects due to a nearby lightning strike. Aim of this work is the evaluation of: the induced surface currents on the antenna unit, the currents flowing through the slip-ring (electro-mechanical part connecting the rotating part of the antenna with the fixed one) and the associated dissipated energy, the currents and voltages across the grounding conductors connecting the different units of the mobile radar system. A three dimensional full wave electromagnetic analysis is performed to characterize the induced currents on the antenna unit. This unit is the transformed in an equivalent voltage source. This circuit element is connected to the equivalent circuit model of the grounding cables and rods of the other units to compute the required electrical variables.
{"title":"Induced currents due to nearby lightning strike to a mobile radar system: an hybrid 3D/circuit analysis","authors":"G. Antonini, M. Cocchini, A. Dominicis, M. Italiani, A. Orlandi","doi":"10.1109/EMCZUR.2007.4388233","DOIUrl":"https://doi.org/10.1109/EMCZUR.2007.4388233","url":null,"abstract":"The presence of a lightning protection system for mobile radar structure requires a detailed study of the electromagnetic effects due to a nearby lightning strike. Aim of this work is the evaluation of: the induced surface currents on the antenna unit, the currents flowing through the slip-ring (electro-mechanical part connecting the rotating part of the antenna with the fixed one) and the associated dissipated energy, the currents and voltages across the grounding conductors connecting the different units of the mobile radar system. A three dimensional full wave electromagnetic analysis is performed to characterize the induced currents on the antenna unit. This unit is the transformed in an equivalent voltage source. This circuit element is connected to the equivalent circuit model of the grounding cables and rods of the other units to compute the required electrical variables.","PeriodicalId":397061,"journal":{"name":"2007 18th International Zurich Symposium on Electromagnetic Compatibility","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125717740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-11-27DOI: 10.1109/EMCZUR.2007.4388256
D. Assante, L. Verolino
This paper deals with the evaluation of the frequencydependent transverse line parameters C and G of coupled microstrips on a lossy substrate. The proposed full wave approach, combined with the use of the Neumann series, allows a simple and fast computing solution of the problem and accurately takes into account the proximity effect between the microstrips. The method can also be useful for the validation of simple closed-form expressions.
{"title":"Transverse line parameters of coupled microstrips on a lossy substrate","authors":"D. Assante, L. Verolino","doi":"10.1109/EMCZUR.2007.4388256","DOIUrl":"https://doi.org/10.1109/EMCZUR.2007.4388256","url":null,"abstract":"This paper deals with the evaluation of the frequencydependent transverse line parameters C and G of coupled microstrips on a lossy substrate. The proposed full wave approach, combined with the use of the Neumann series, allows a simple and fast computing solution of the problem and accurately takes into account the proximity effect between the microstrips. The method can also be useful for the validation of simple closed-form expressions.","PeriodicalId":397061,"journal":{"name":"2007 18th International Zurich Symposium on Electromagnetic Compatibility","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128938100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-11-27DOI: 10.1109/EMCZUR.2007.4388185
D. Baumann, C. Fumeaux, R. Vahldieck, E. Li
The performance of three different antennas typically used in EMC testings is thoroughly analyzed: A doubleridged horn, a trapezoidal logarithmic-periodic, and a biconical antenna. Those antennas are briefly compared considering their relevant characteristics, their radiation patterns, and their operational frequency range. However, the emphasis of this paper is placed on the relevant aspects regarding their numerical modeling. In order to obtain reliable and highly precise simulation results, certain significant simulation guidelines should be followed, amongst others how to include the feeding in the models. The Finite-Volume Time-Domain (FVTD) method is applied here as an appropriate numerical tool in order to accomplish accurate simulations. The method exploits conformal meshing and therefore is capable of precisely modeling fine structural details in close proximity to an overall large structure.
{"title":"Rigorous characterization of EMC antennas","authors":"D. Baumann, C. Fumeaux, R. Vahldieck, E. Li","doi":"10.1109/EMCZUR.2007.4388185","DOIUrl":"https://doi.org/10.1109/EMCZUR.2007.4388185","url":null,"abstract":"The performance of three different antennas typically used in EMC testings is thoroughly analyzed: A doubleridged horn, a trapezoidal logarithmic-periodic, and a biconical antenna. Those antennas are briefly compared considering their relevant characteristics, their radiation patterns, and their operational frequency range. However, the emphasis of this paper is placed on the relevant aspects regarding their numerical modeling. In order to obtain reliable and highly precise simulation results, certain significant simulation guidelines should be followed, amongst others how to include the feeding in the models. The Finite-Volume Time-Domain (FVTD) method is applied here as an appropriate numerical tool in order to accomplish accurate simulations. The method exploits conformal meshing and therefore is capable of precisely modeling fine structural details in close proximity to an overall large structure.","PeriodicalId":397061,"journal":{"name":"2007 18th International Zurich Symposium on Electromagnetic Compatibility","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125482279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-11-27DOI: 10.1109/EMCZUR.2007.4388298
P. Kay, F. Schlagenhaufer, Hongmei Fan
A hybrid TEM-reverberation chamber would allow efficient radiated field immunity tests to be performed from DC to microwave frequencies in a single facility. TEM cells are limited to testing comparatively small equipment at relatively low frequencies. Reverberation chambers must be very large to be effective at low frequencies, because the statistical properties of the randomly polarised field break down when insufficient mode stirring occurs [1]. Since there is no frequency overlap between TEM and reverberation operation for a chamber of any given size, a combined TEM/reverberation facility must also operate in a transition mode in order to cover the entire frequency band. This paper proposes performance parameters for overmoded TEM and undermoded reverberation frequency ranges, and gives an example of how the figures of merit can be used to evaluate potential hybrid cell designs.
{"title":"Figures of Merit for a Hybrid TEM-Reverberation Chamber","authors":"P. Kay, F. Schlagenhaufer, Hongmei Fan","doi":"10.1109/EMCZUR.2007.4388298","DOIUrl":"https://doi.org/10.1109/EMCZUR.2007.4388298","url":null,"abstract":"A hybrid TEM-reverberation chamber would allow efficient radiated field immunity tests to be performed from DC to microwave frequencies in a single facility. TEM cells are limited to testing comparatively small equipment at relatively low frequencies. Reverberation chambers must be very large to be effective at low frequencies, because the statistical properties of the randomly polarised field break down when insufficient mode stirring occurs [1]. Since there is no frequency overlap between TEM and reverberation operation for a chamber of any given size, a combined TEM/reverberation facility must also operate in a transition mode in order to cover the entire frequency band. This paper proposes performance parameters for overmoded TEM and undermoded reverberation frequency ranges, and gives an example of how the figures of merit can be used to evaluate potential hybrid cell designs.","PeriodicalId":397061,"journal":{"name":"2007 18th International Zurich Symposium on Electromagnetic Compatibility","volume":"214 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132417472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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