Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.最新文献
Pub Date : 2004-12-27DOI: 10.1109/DIPED.2004.242570
D. Karkashadze, R. Jobava, S. Frei, D. Topchishvili, G. Muchaidze
In car related EMC problems, it is important to estimate radiation from, or coupling into, the cable harness, which comprises of a large number of wires located in close proximity. When wires are considered, decreasing the length of a wire segment does not improve accuracy if any other object is located extremely close to the surface of the wire. In this case, charge is distributed non-uniformly along the perimeter. The surface of the wire segment must be divided into strips, and charges at each strip must be found independently. A "thick wire" approach, which includes additional segmentation along the perimeter, can bring an enormous increase in the number of unknowns. We report on the implementation of a thick wire approach based on the method of auxiliary sources (MAS). Results of investigations are given as recommendations in graphical and tabular views, which show the accuracy of the calculated values for benchmark problems. These recommendations will be used in the latest versions (v. 1.14 and higher) of the three dimensional static solver Satic3D developed at EMCoS.
{"title":"Calculation of 3D capacitances of wires with hybrid MoM/MAS approach","authors":"D. Karkashadze, R. Jobava, S. Frei, D. Topchishvili, G. Muchaidze","doi":"10.1109/DIPED.2004.242570","DOIUrl":"https://doi.org/10.1109/DIPED.2004.242570","url":null,"abstract":"In car related EMC problems, it is important to estimate radiation from, or coupling into, the cable harness, which comprises of a large number of wires located in close proximity. When wires are considered, decreasing the length of a wire segment does not improve accuracy if any other object is located extremely close to the surface of the wire. In this case, charge is distributed non-uniformly along the perimeter. The surface of the wire segment must be divided into strips, and charges at each strip must be found independently. A \"thick wire\" approach, which includes additional segmentation along the perimeter, can bring an enormous increase in the number of unknowns. We report on the implementation of a thick wire approach based on the method of auxiliary sources (MAS). Results of investigations are given as recommendations in graphical and tabular views, which show the accuracy of the calculated values for benchmark problems. These recommendations will be used in the latest versions (v. 1.14 and higher) of the three dimensional static solver Satic3D developed at EMCoS.","PeriodicalId":126782,"journal":{"name":"Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127385997","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 : 2004-12-27DOI: 10.1109/DIPED.2004.242571
D. Topchishvili, R. Jobava, F. Bogdanov, B. Chikhradze, S. Frei
A hybrid approach is presented that combines the method of transmission lines (MTL) with the method of moments (MoM) to solve electromagnetic radiation problems on structures consisting of wires with complex terminations and three-dimensional conducting bodies. This approach is based on calculating the currents on wires using MTL and converting them to external sources for the remaining geometry to be handled by MoM. Validation of the MTL/MoM approach is done, its application to different wire, circuit and body configurations, including wire bunches, is illustrated, and its advantage over direct MoM calculations is shown.
{"title":"A hybrid MTL/MoM approach for investigation of radiation problems in EMC","authors":"D. Topchishvili, R. Jobava, F. Bogdanov, B. Chikhradze, S. Frei","doi":"10.1109/DIPED.2004.242571","DOIUrl":"https://doi.org/10.1109/DIPED.2004.242571","url":null,"abstract":"A hybrid approach is presented that combines the method of transmission lines (MTL) with the method of moments (MoM) to solve electromagnetic radiation problems on structures consisting of wires with complex terminations and three-dimensional conducting bodies. This approach is based on calculating the currents on wires using MTL and converting them to external sources for the remaining geometry to be handled by MoM. Validation of the MTL/MoM approach is done, its application to different wire, circuit and body configurations, including wire bunches, is illustrated, and its advantage over direct MoM calculations is shown.","PeriodicalId":126782,"journal":{"name":"Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128795146","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 : 2004-12-27DOI: 10.1109/DIPED.2004.242457
D. Kuryliak, M. Voytko
We rigorously analyze the SH (shear horizontal) elastic wave diffraction for the finite crack located between the plane interface of the slab and the half-space medium. The incident field is taken as a plane wave. Introducing the Fourier transform of the scattered field and applying boundary conditions in the transform domain, the problem is formulated in terms of the Wiener-Hopf equation. The Wiener-Hopf equation is solved exactly via a factorization procedure leading to the formal solution. An approximate solution of such an equation is proposed.
{"title":"Wiener-Hopf analysis of the elastic wave diffraction by the finite crack located at the plane interface between the elastic isotropic slab and half-space medium","authors":"D. Kuryliak, M. Voytko","doi":"10.1109/DIPED.2004.242457","DOIUrl":"https://doi.org/10.1109/DIPED.2004.242457","url":null,"abstract":"We rigorously analyze the SH (shear horizontal) elastic wave diffraction for the finite crack located between the plane interface of the slab and the half-space medium. The incident field is taken as a plane wave. Introducing the Fourier transform of the scattered field and applying boundary conditions in the transform domain, the problem is formulated in terms of the Wiener-Hopf equation. The Wiener-Hopf equation is solved exactly via a factorization procedure leading to the formal solution. An approximate solution of such an equation is proposed.","PeriodicalId":126782,"journal":{"name":"Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.","volume":"190 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116868317","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 : 2004-12-27DOI: 10.1109/DIPED.2004.242677
E. Nikolaeva, D. Nikolaev, L. Shoshiashvili, R. Zaridze
The thermal effects of a cellular phone electromagnetic (EM) field on the human head were studied by computer simulation. A structural heterogeneous realistic model of the human head was used. EM analysis was performed via the finite-difference time-domain (FDTD) method (Taflove, A. and Hagness, S.C., "Computational Electrodynamics: the finite difference time-domain method", Artech House, 2000). Specific absorption rate (SAR) was evaluated and further thermal effects were investigated using the bioheat (BH) equation (Bernardi, P. and Pisa, S., IEEE Trans. Microwave Theory Tech., vol.48, p.1118-26, 1998); the temperature field distribution and temperature rise were investigated for different frequencies, powers and exposure times. The results show that exposure time and environmental temperature must be two of the characteristic quantities in a safety standard.
通过计算机模拟研究了手机电磁场对人体头部的热效应。采用了一种结构异质逼真的人头模型。EM分析通过时域有限差分(FDTD)方法进行(Taflove, A.和Hagness, S.C.，“计算电动力学:时域有限差分方法”，Artech House, 2000)。利用生物热(BH)方程(Bernardi, P. and Pisa, S.， IEEE Trans)评估了比吸收率(SAR)并进一步研究了热效应。微波理论技术，vol.48, p.1118- 26,1998);研究了不同频率、功率和曝光时间下的温度场分布和温升。结果表明，暴露时间和环境温度必须是安全标准中的两个特征量。
{"title":"Analysis of thermal effects in human exposed to EM radiation (2D case)","authors":"E. Nikolaeva, D. Nikolaev, L. Shoshiashvili, R. Zaridze","doi":"10.1109/DIPED.2004.242677","DOIUrl":"https://doi.org/10.1109/DIPED.2004.242677","url":null,"abstract":"The thermal effects of a cellular phone electromagnetic (EM) field on the human head were studied by computer simulation. A structural heterogeneous realistic model of the human head was used. EM analysis was performed via the finite-difference time-domain (FDTD) method (Taflove, A. and Hagness, S.C., \"Computational Electrodynamics: the finite difference time-domain method\", Artech House, 2000). Specific absorption rate (SAR) was evaluated and further thermal effects were investigated using the bioheat (BH) equation (Bernardi, P. and Pisa, S., IEEE Trans. Microwave Theory Tech., vol.48, p.1118-26, 1998); the temperature field distribution and temperature rise were investigated for different frequencies, powers and exposure times. The results show that exposure time and environmental temperature must be two of the characteristic quantities in a safety standard.","PeriodicalId":126782,"journal":{"name":"Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.","volume":"351 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115465655","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 : 2004-12-27DOI: 10.1109/DIPED.2004.242573
K. Tavzarashvili, G. Ghvedashvili, D. Kakulia, D. Karkashadze, R. Zaridze
The development of the method of auxiliary sources (MAS) and the algorithm of the eigen-function series (EFS) for modeling the open cable radiation problem is presented. A coaxial cable with a central projection on the open end is considered. Two ways to describe the field inside the cable in case of heterogeneity on the cable end are supposed: (1) general MAS algorithm; (2) algorithm of EFS representation of the electromagnetic (EM) field inside the cable. Numerical results are presented with real experimental measurements to show the reliability of investigation.
{"title":"The method of auxiliary sources and eigen-function series representation for modeling of the open cable radiation problem","authors":"K. Tavzarashvili, G. Ghvedashvili, D. Kakulia, D. Karkashadze, R. Zaridze","doi":"10.1109/DIPED.2004.242573","DOIUrl":"https://doi.org/10.1109/DIPED.2004.242573","url":null,"abstract":"The development of the method of auxiliary sources (MAS) and the algorithm of the eigen-function series (EFS) for modeling the open cable radiation problem is presented. A coaxial cable with a central projection on the open end is considered. Two ways to describe the field inside the cable in case of heterogeneity on the cable end are supposed: (1) general MAS algorithm; (2) algorithm of EFS representation of the electromagnetic (EM) field inside the cable. Numerical results are presented with real experimental measurements to show the reliability of investigation.","PeriodicalId":126782,"journal":{"name":"Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.","volume":"321 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115750565","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 : 2004-12-27DOI: 10.1109/DIPED.2004.242801
A. Dumin, O. Dumina, V. Katrich, M. Nesterenko
The problem of waveguide coupling by a narrow slot is solved by the method of induced magnetomotive forces. Using an approximate analytical solution of integral differential equations on the magnetic current, the current distribution on a slot can be found. The results of calculation of transmission power of different types of slot are compared with the same ones obtained by the FDTD method.
{"title":"Method of induced magnetomotive forces in comparison with FDTD simulation in problems of waveguide coupling by a narrow slot","authors":"A. Dumin, O. Dumina, V. Katrich, M. Nesterenko","doi":"10.1109/DIPED.2004.242801","DOIUrl":"https://doi.org/10.1109/DIPED.2004.242801","url":null,"abstract":"The problem of waveguide coupling by a narrow slot is solved by the method of induced magnetomotive forces. Using an approximate analytical solution of integral differential equations on the magnetic current, the current distribution on a slot can be found. The results of calculation of transmission power of different types of slot are compared with the same ones obtained by the FDTD method.","PeriodicalId":126782,"journal":{"name":"Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127584434","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 : 2004-12-27DOI: 10.1109/DIPED.2004.242808
V. Chekurin, O. Kravchyshyn
Within the scope of the model of a quasi-plane wave, the propagation of a strain pulse in a given direction in solids with an inhomogeneous stress field is considered. The effect of the non-homogeneity of the initial stress-strain state on the pulse propagation time and its shape change is studied.
{"title":"Effect of initial stress field on propagation velocity and shape of strain pulse","authors":"V. Chekurin, O. Kravchyshyn","doi":"10.1109/DIPED.2004.242808","DOIUrl":"https://doi.org/10.1109/DIPED.2004.242808","url":null,"abstract":"Within the scope of the model of a quasi-plane wave, the propagation of a strain pulse in a given direction in solids with an inhomogeneous stress field is considered. The effect of the non-homogeneity of the initial stress-strain state on the pulse propagation time and its shape change is studied.","PeriodicalId":126782,"journal":{"name":"Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129928094","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 : 2004-12-27DOI: 10.1109/DIPED.2004.242937
E. Belyavskiy, I.V. Shevelenok, S. Khotiaintsev
We present a mathematical linear 2D model of the interaction of the synchronous forward and backward harmonics of the electromagnetic wave, existing in the slow-wave circuit, with the electron beam in a monofilar-helix traveling-wave tube (TWT) under periodic permanent magnetic (PPM) focusing. We accounted for the effect of the electron beam alternating rotation in the PPM focusing field, magnetic field amplitude and periodicity, and the specific coupling of the electron beam with the circuit wave. This coupling takes place in the monofilar-helix TWT only and decreases its stability with respect to the parasitic backward-wave oscillation in comparison to other types of helix TWT.
{"title":"Small-signal two-dimensional model of parasitic backward-wave oscillation in a monofilar-helix traveling-wave tube","authors":"E. Belyavskiy, I.V. Shevelenok, S. Khotiaintsev","doi":"10.1109/DIPED.2004.242937","DOIUrl":"https://doi.org/10.1109/DIPED.2004.242937","url":null,"abstract":"We present a mathematical linear 2D model of the interaction of the synchronous forward and backward harmonics of the electromagnetic wave, existing in the slow-wave circuit, with the electron beam in a monofilar-helix traveling-wave tube (TWT) under periodic permanent magnetic (PPM) focusing. We accounted for the effect of the electron beam alternating rotation in the PPM focusing field, magnetic field amplitude and periodicity, and the specific coupling of the electron beam with the circuit wave. This coupling takes place in the monofilar-helix TWT only and decreases its stability with respect to the parasitic backward-wave oscillation in comparison to other types of helix TWT.","PeriodicalId":126782,"journal":{"name":"Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127609616","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 : 2004-12-27DOI: 10.1109/DIPED.2004.242936
E. Belyavskiy, S. Khotiaintsev
We present a mathematical nonlinear model of the parasitic backward-wave oscillation in the generic helix TWT under permanent periodic magnetic (PPM) focusing. The model accounts for the interaction of the electromagnetic wave existing on the helix slow-wave circuit and the electron beam alternating rotation in the PPM focusing field. We obtain an equation system, which permits us to find the start-oscillation length of the parasitic backward-wave oscillation and real starting Pierce's relative velocity parameter as functions of the PPM focusing field period and amplitude, and the electrical parameters of the TWT in the large-signal regime. We show that the electron beam alternating rotation in the PPM focusing field has a significant effect on the TWT stability with respect to the parasitic backward-wave oscillation in the nonlinear regime, as it has in the linear one.
{"title":"Nonlinear model of the parasitic backward-wave oscillation in the traveling wave tube under periodic permanent magnetic focusing","authors":"E. Belyavskiy, S. Khotiaintsev","doi":"10.1109/DIPED.2004.242936","DOIUrl":"https://doi.org/10.1109/DIPED.2004.242936","url":null,"abstract":"We present a mathematical nonlinear model of the parasitic backward-wave oscillation in the generic helix TWT under permanent periodic magnetic (PPM) focusing. The model accounts for the interaction of the electromagnetic wave existing on the helix slow-wave circuit and the electron beam alternating rotation in the PPM focusing field. We obtain an equation system, which permits us to find the start-oscillation length of the parasitic backward-wave oscillation and real starting Pierce's relative velocity parameter as functions of the PPM focusing field period and amplitude, and the electrical parameters of the TWT in the large-signal regime. We show that the electron beam alternating rotation in the PPM focusing field has a significant effect on the TWT stability with respect to the parasitic backward-wave oscillation in the nonlinear regime, as it has in the linear one.","PeriodicalId":126782,"journal":{"name":"Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127773220","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 : 2004-12-27DOI: 10.1109/DIPED.2004.242804
M. Andriychuk
Some generalizations of the variational statement for the problem of antenna synthesis according to a prescribed amplitude radiation pattern (RP) are examined. An additional summand is included in optimizing the functional, that allows the electromagnetic field to be minimized in the near zone. The respective nonlinear Euler's equation is obtained and investigated by numerical methods. The results of numerical modeling are represented. They show the opportunity for the formation of nulls in the synthesized RPs, as well as a decrease of field amplitude in given areas of the near zone.
{"title":"Generalized variational approach to the waveguide array synthesis","authors":"M. Andriychuk","doi":"10.1109/DIPED.2004.242804","DOIUrl":"https://doi.org/10.1109/DIPED.2004.242804","url":null,"abstract":"Some generalizations of the variational statement for the problem of antenna synthesis according to a prescribed amplitude radiation pattern (RP) are examined. An additional summand is included in optimizing the functional, that allows the electromagnetic field to be minimized in the near zone. The respective nonlinear Euler's equation is obtained and investigated by numerical methods. The results of numerical modeling are represented. They show the opportunity for the formation of nulls in the synthesized RPs, as well as a decrease of field amplitude in given areas of the near zone.","PeriodicalId":126782,"journal":{"name":"Proceedings of the 9th International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory, 2004. DIPED 2004.","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133674862","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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