2007 ieee international symposium on electromagnetic compatibility
2007 ieee international symposium on electromagnetic compatibility
2007 ieee international symposium on electromagnetic compatibility
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EMC <str<strong>on</strong>g>2007</str<strong>on</strong>g> ADVANCE PROGRAM 17imbalance <strong>on</strong> radiated emissi<strong>on</strong> of cables inside a commercial 19-inchrack-based cabinet. Scattering parameters (S-parameters) for two setsof cable assembly are measured with a four-port vector network analyzer(VNA) and c<strong>on</strong>verted into mixed mode S-parameters. Timedomaininput signals with different slew rates and different amountof skew are transferred into frequency-domain using fast Fouriertransform (FFT). The spectra of radiati<strong>on</strong> emissi<strong>on</strong> associated withdifferent inputs are then estimated.EMI Emissi<strong>on</strong>s from Mismatches in High Speed DifferentialSignal Traces and CablesBruce Archambeault; Jay Diepenbrock; and Sam C<strong>on</strong>nor, — IBMCorporati<strong>on</strong>The use of so-called differential signaling for high speed signals hasbecome very comm<strong>on</strong> in today’s high speed system designs. While thissignal strategy allows better data quality and signal integrity, there aresome significant EMC and signal integrity issues that are not readilyapparent. This paper dem<strong>on</strong>strates that a significant amount of comm<strong>on</strong>-modecurrent can be created when the two legs of the differentialsignal are skewed in time, or if the rise and fall times of the signals differ.These comm<strong>on</strong> mode currents can impact the EMC performance,causing significant levels of emissi<strong>on</strong>s unless careful design c<strong>on</strong>siderati<strong>on</strong>is given to shielding and comm<strong>on</strong>-mode (ground) current return.EMI Design of Shielded Cable AssembliesJim Nadolny, SamtecMost discussi<strong>on</strong>s <strong>on</strong> shielding for EMC address the shielding of enclosuresand give rules of thumb regarding the size of slots and holes.These recommendati<strong>on</strong>s are not applicable in general to the design ofshielded cable assemblies. Because there exists a gap in publishedinformati<strong>on</strong> <strong>on</strong> the unique shielding requirements for cable assemblies,this document was generated. The scope of this document isthat it will apply to low cost, shielded multic<strong>on</strong>ductor, cable assemblies.While some of this informati<strong>on</strong> will be applicable to coaxial RFcable assemblies, this is not the main focus of this document.EMC MEASUREMENTS IIAnalysis of Radiated Emissi<strong>on</strong>s and Shielding Effectivenessfor a Metallic Enclosure with Shielding SpringsGiulio Ant<strong>on</strong>ini, University of L’Aquila; Ant<strong>on</strong>io Orlandi, University ofL’Aquila; and Ant<strong>on</strong>io Ciccomancini, CST of AmericaThe high speed digital processing in modern electr<strong>on</strong>ic products hasmade more difficult the achievement of c<strong>on</strong>formity about limits emissi<strong>on</strong>s.To verify the requirements of standards <strong>on</strong> these emissi<strong>on</strong>s theuse of a metallic enclosure is often necessary; in this way the powerradiated by the system is reduced. In this paper the radiated emissi<strong>on</strong>sand the shielding performance of a metallic rack with shielding springsare studied both by dedicated experiments and by simulati<strong>on</strong>s. Aninternal source represented by a loaded m<strong>on</strong>opole antenna is used toinvestigate the radiated emissi<strong>on</strong>s 3 meters from the box. A simplifiedmodel of the antenna source is proposed in the numerical model and agood agreement over a frequency range up to 1 GHz is achievedbetween measured results and simulated results. Shielding effectivenessis finally evaluated by means of two different kinds of sources: 1)near field (internal source) and 2) far field (plane wave source).Logistic Regressi<strong>on</strong> in Immunity TestingGiorgio Giunta; and Bruno Aud<strong>on</strong>e, — Oerlik<strong>on</strong> C<strong>on</strong>travesLogistic Regressi<strong>on</strong>, a statistical analysis tool used for epidemiologicalstudies, can be successfully exploited to interpret susceptibilitytest results with the twofold aim of understanding which are themost significant causes affecting the Device under Test (DUT) and ofproviding a technique to define a global figure of safety margin whenmany test parameters are involved. The background of LogisticRegressi<strong>on</strong> is briefly summarized and then a graphical interpretati<strong>on</strong>of test results is provided. Finally, the experimental validati<strong>on</strong> of themethod is described.The Proposal of a New Approach to Immunity TestingMichela Aud<strong>on</strong>e, Centro Ricerche Fiat; and Bruno Aud<strong>on</strong>e, Oerlik<strong>on</strong>C<strong>on</strong>travesThe need of performing immunity tests with the aim of meeting therequirements of Functi<strong>on</strong>al Safety is addressed proposing severalapproaches based up<strong>on</strong> the data processing of test results. This representsa clear improvement with respect to the present situati<strong>on</strong> ofEMC standards based up<strong>on</strong> simple qualitative checks, which do notoffer any warranty of safety. Even if the equipment under test (EUT)is declared immune in normal operative c<strong>on</strong>diti<strong>on</strong>s, it may happenthat a simple envir<strong>on</strong>mental effect such as temperature variati<strong>on</strong> hascatastrophic c<strong>on</strong>sequences. The test results of radiated immunitytests performed <strong>on</strong> a DC/DC c<strong>on</strong>verter are processed according to theAnova model, which is <strong>on</strong>e of the proposed approaches.REVERBERATION CHAMBER MEASUREMENTS IReverberati<strong>on</strong> Chamber Calibrati<strong>on</strong>: Differences in ResultsWhen Using a Slot Instead of a Dipole AntennaTobias Aurand; John Daws<strong>on</strong>; Andrew Marvin; and Martin Robins<strong>on</strong>, —University of YorkThis paper c<strong>on</strong>siders the use of a slot antenna in the calibrati<strong>on</strong> of areverberati<strong>on</strong> chamber. In using a slot antenna the need for a balunis reduced which simplifies antenna c<strong>on</strong>structi<strong>on</strong>. The behaviour ofa slot antenna is compared to a dipole antenna and it is found that thefield uniformity results obtained with a slot are more pessimisticthan the <strong>on</strong>es with a dipole. Whilst the slot is usable for calibrati<strong>on</strong>of a reverberati<strong>on</strong> chamber, it seems that the slot is more sensitive tosome field n<strong>on</strong>uniformities than the dipole.Pulsed Power 3 GHz Feasibility Study for a 36.7 m3 ModeStirred Reverberati<strong>on</strong> ChamberOlof Lunden, FOI; and Mats Bäckström, Saab Communicati<strong>on</strong>A feasibility study was c<strong>on</strong>ducted to investigate the field build upprocess in a 36.7 m3 reverberati<strong>on</strong> chamber. The time to get a steadyfield state in the unloaded chamber will normally be about 10 to 20µs. However, it is of great interest to investigate what field levels canbe expected for an ordinary radar source. The particular 700 kW S-band radar we have at our disposal has a typical pulse durati<strong>on</strong> of 1µs. A maximum field strength of approximately 35 kV/m wasachieved for 309 kW of input power. The voltage ratio, VR, betweenthe ensemble maxima, with a chamber time c<strong>on</strong>stant equal to about10 µs and the magnetr<strong>on</strong> pulse of <strong>on</strong>ly 1 µs, was found to be 0.54 or-5.4 dB. The pulse characteristics have also been investigated whenloading the chamber according to the aviati<strong>on</strong> test standard RTCADO-160.Enhanced Backscatter in a Reverberati<strong>on</strong> Chamber: Inside EveryComplex Problem is a Simple Soluti<strong>on</strong> Struggling to Get OutJohn Ladbury; and David Hill, — Nati<strong>on</strong>al Institute of Standards andTechnology (NIST)We encountered problems when we attempted to model the behaviorof a transmitting antenna in a reverberati<strong>on</strong> chamber. Our model©<str<strong>on</strong>g>2007</str<strong>on</strong>g> IEEE www.emc<str<strong>on</strong>g>2007</str<strong>on</strong>g>.org