BEGIN:VCALENDAR VERSION:2.0 PRODID:IEEE vTools.Events//EN CALSCALE:GREGORIAN BEGIN:VTIMEZONE TZID:Europe/Zurich BEGIN:DAYLIGHT DTSTART:20180325T030000 TZOFFSETFROM:+0100 TZOFFSETTO:+0200 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=3 TZNAME:CEST END:DAYLIGHT BEGIN:STANDARD DTSTART:20181028T020000 TZOFFSETFROM:+0200 TZOFFSETTO:+0100 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10 TZNAME:CET END:STANDARD END:VTIMEZONE BEGIN:VEVENT DTSTAMP:20180611T065613Z UID:07395F38-89D2-416D-947E-5377EB95304E DTSTART;TZID=Europe/Zurich:20180605T110000 DTEND;TZID=Europe/Zurich:20180605T130000 DESCRIPTION:The coupling of high-frequency electromagnetic fields with tran smission lines of different nature is one of the main problems of electrom agnetic compatibility. Numerical methods\, like the Method of Moments\, al lows to obtain results for specific cases only\, but do not describe the g eneral physical features of the problem. Coupling with transmission lines is a special case of interaction of EM fields with scattering objects. For solution of this problem the general Singularity Expansion Method (SEM) w as advanced by C.Baum\, F. Tesche\, D. Giri and other scientists in earlie r 1970th. The method allows to obtain results both in frequency and time d omain by analysis of the poles of the response function (SEM poles) in the complex plane. The positions of poles are a unique characteristic of the system and do not dependent on the kind of excitation and position of the current measurement point\, The SEM expansion defines the response\, radia tion of the system\, its scattering amplitude\, etc.\n\nThe thin - wire tr ansmission lines have some peculiarities\, which essentially simplify the problem of analysis of SEM-expansion for such systems. In this presentatio n we describe some results of application of Singularity Expansion Method for the non-uniform transmission line obtained in the Chair of Electromagn etic Compatibility of the Otto-von-Guericke University. Two approaches wil l be described.\n\nIn the first\, so-called asymptotic approach\, we consi der a long straight loaded line above a perfect conducting ground with arb itrary terminals illuminated by an incident high frequency plane wave. In this approach\, far from the terminals\, in the so called asymptotic regio n the current has a simple structure: it consists of forward and backward running TEM waves and the exact solution for the current for the case of i nfinite wire. The coefficients for the TEM waves contains\, in particular\ , the resonance denominator\, which\, in turn\, includes of reflection coe fficients of TEM current waves from the left and right terminals and the e xponential propagator factor. These reflection coefficients can be calcula ted using the perturbation theory for thin wires or by an analysis of nume rical results. The zeros of the resonance denominator yield the SEM poles of the first layer. This set of poles yields the main contribution to the susceptibility of the transmission line to an external pulse excitation in time domain. Furthermore\, SEM poles can be obtained in an explicit form for two canonical cases: (i) an open-circuit wire\, and (ii) a horizontal wire short-circuited by vertical risers. The method also can be generalize d for the case of multiconductor lines.\n\nThe second method\, which was a pplied for investigation of the SEM poles of thin-wire line of arbitrary g eometric form\, is a method of modal parameters. In this method the exact integro-differential equations describing the coupling problem is reduced to the system of two matrix equations with infinite inductance and capacit ance matrices by a spatial Fourier series transformation. The inductance a nd capacitance matrices are matrix elements of the kern of the first and s econd integral equation\, correspondingly\, for the spatial Fourier series . The solution for the induced current column can be found by the product of the column of the initial tangential electric field with the inverse in finite impedance matrix\, which can be obtained from the inductance and ca pacitance matrix by the usual way. Thus\, the SEM poles of the induced cur rents in the complex plane are given by the eigen - values of the infinite impedance matrix.\n\nThe obtained results for SEM poles were compared wit h numerical one extracted by analysis of numerical NEC data and also with the results of processing the measurements of the transmission line in GTE M - cell. In both cases\, a good agreement was obtained between theory\, m easurement and numerical simulation.\n\nCo-sponsored by: EMC Laboratory - EPFL\n\nSpeaker(s): Dr. Sergey Tkachenko\, \n\nRoom: ELD120\, EPFL\, Lausa nne\, Switzerland\, Switzerland\, 1015 Lausanne LOCATION:Room: ELD120\, EPFL\, Lausanne\, Switzerland\, Switzerland\, 1015 Lausanne ORGANIZER:nicolas.mora@epfl.ch SEQUENCE:4 SUMMARY:Application of Singularity Expansion Method (SEM) to non-uniform tr ansmission lines URL;VALUE=URI:https://events.vtools.ieee.org/m/173467 X-ALT-DESC:Description: <br /><p>The coupling of high-frequency electromagn etic fields with transmission lines of different nature is one of the main problems of electromagnetic compatibility. Numerical methods\, like the M ethod of Moments\, allows to obtain results for specific cases only\, but do not describe the general physical features of the problem. Coupling wit h transmission lines is a special case of interaction of EM fields with sc attering objects. For solution of this problem the general Singularity Exp ansion Method (SEM) was advanced by C.Baum\, F. Tesche\, D. Giri and other scientists in earlier 1970th. The method allows to obtain results both in frequency and time domain by analysis of the poles of the response functi on (SEM poles) in the complex plane. The positions of poles are a unique c haracteristic of the system and do not dependent on the kind of excitation and position of the current measurement point\, The SEM expansion defines the response\, radiation of the system\, its scattering amplitude\, etc.< /p>\n<p>The thin - wire transmission lines have some peculiarities\, which essentially simplify the problem of analysis of SEM-expansion for such sy stems. In this presentation we describe some results of application of Sin gularity Expansion Method for the non-uniform transmission line obtained i n the Chair of Electromagnetic Compatibility of the Otto-von-Guericke Univ ersity. Two approaches will be described.</p>\n<p>In the first\, so-called asymptotic approach\, we consider a long straight loaded line above a per fect conducting ground with arbitrary terminals illuminated by an incident high frequency plane wave. In this approach\, far from the terminals\, in the so called asymptotic region the current has a simple structure: it co nsists of forward and backward running TEM waves and the exact solution fo r the current for the case of infinite wire. The coefficients for the TEM waves contains\, in particular\, the resonance denominator\, which\, in tu rn\, includes of reflection coefficients of TEM current waves from the lef t and right terminals and the exponential propagator factor. These reflect ion coefficients can be calculated using the perturbation theory for thin wires or by an analysis of numerical results.&nbsp\; The zeros of the reso nance denominator yield the SEM poles of the first layer. This set of pole s yields the main contribution to the susceptibility of the transmission l ine to an external pulse excitation in time domain. Furthermore\, SEM pole s can be obtained in an explicit form for two canonical cases: (i) an open -circuit wire\, and (ii) a horizontal wire short-circuited by vertical ris ers. The method also can be generalized for the case of multiconductor lin es.</p>\n<p>The second method\, which was applied for investigation of the SEM poles of thin-wire line of arbitrary geometric form\, is a method of modal parameters. In this method the exact integro-differential equations describing the coupling problem is reduced to the system of two matrix equ ations with infinite inductance and capacitance matrices by a spatial Four ier series transformation. The inductance and capacitance matrices are mat rix elements of the kern of the first and second integral equation\, corre spondingly\, for the spatial Fourier series. The solution for the induced current column can be found by the product of the column of the initial ta ngential electric field with the inverse infinite impedance matrix\, which can be obtained from the inductance and capacitance matrix by the usual w ay. Thus\, the SEM poles of the induced currents in the complex plane are given by the eigen - values of the infinite impedance matrix.</p>\n<p>The obtained results for SEM poles were compared with numerical one extracted& nbsp\; by analysis of numerical NEC data&nbsp\; and also with the results of processing the measurements of the transmission line in GTEM - cell. In both cases\, a good agreement was obtained between theory\, measurement&n bsp\; and numerical simulation.</p> END:VEVENT END:VCALENDAR