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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22EMC <str<strong>on</strong>g>2007</str<strong>on</strong>g> ADVANCE PROGRAMmode (DM) current <strong>on</strong> the signal trace, and cross-talk current <strong>on</strong> thevictim traces. C<strong>on</strong>sequently, correct predicti<strong>on</strong>s of CM current atlower frequencies and cross-talk are keys to the predicti<strong>on</strong> of the totalEMI behavior of the interc<strong>on</strong>nected PCBs, because the DM current<strong>on</strong> the signal trace can be predicted by transmissi<strong>on</strong> line theory.Power and Ground Bounce Effects <strong>on</strong> Comp<strong>on</strong>ent PerformanceBased <strong>on</strong> Printed Circuit Board Edge Terminati<strong>on</strong> MethodologiesMark M<strong>on</strong>trose, M<strong>on</strong>trose Compliance Services, Inc.; and En-Xiao Liu,Institute of High Performance ComputingPrinted circuit boards (PCBs) are <strong>on</strong>e source of radiated EMI withdigital comp<strong>on</strong>ents being the culprits. To minimize the developmentof comm<strong>on</strong>-mode currents within the silic<strong>on</strong> package of largecurrent c<strong>on</strong>suming circuits, a stable power distributi<strong>on</strong> network(PDN) is required. Any noise (bounce) <strong>on</strong> either the power or 0 Vreference (ground) plane may cause, simultaneously, switching noise(SSN) or signal integrity (SI) problems, as well as EMI. In additi<strong>on</strong>,if planar bounce exceeds margin levels, comp<strong>on</strong>ents may not functi<strong>on</strong>.To ensure a stable PDN is present, decoupling capacitors andburied capacitive structures are mandatory, al<strong>on</strong>g with minimizingloop inductance. The uniqueness of this research lies in analyzingplanar bounce that may exceed voltage margin levels from reflectedEM waves that propagate back to comp<strong>on</strong>ents from the physical edgeof the PCB. The edges of a PCB are in reality a high-impedance,n<strong>on</strong>-terminated signal transmissi<strong>on</strong> line stub. With each reflecti<strong>on</strong>,ringing occurs. The magnitude of this ringing may cause digitalcomp<strong>on</strong>ents to have SSN and/or EMI problems. Popular board edgeterminati<strong>on</strong> techniques are investigated to determine if a designershould be c<strong>on</strong>cerned with reflected wave switching noise <strong>on</strong> either apower or 0 V reference plane, which cannot be removed by capacitivestructures or decoupling.Analysis of Emissi<strong>on</strong>s from a Printed Circuit Board with aC<strong>on</strong>ducting Wire Directed in Various Directi<strong>on</strong>sMasahiro Takashima; Teruo Tobana; Takayuki Sasamori; and Kohshi Abe,— Department of Electr<strong>on</strong>ics and Informati<strong>on</strong> Systems, Akita PrefecturalUniversityEmissi<strong>on</strong>s from a printed circuit board (PCB) with a finite sizebecomes serious when the comm<strong>on</strong> mode current is excited <strong>on</strong> it.The comm<strong>on</strong> mode current can occur at c<strong>on</strong>necti<strong>on</strong>s of c<strong>on</strong>ductingwires or at a disc<strong>on</strong>tinuity of a line or ground plane <strong>on</strong> a PCB. Inorder to clarify the relati<strong>on</strong> between a juncti<strong>on</strong> of c<strong>on</strong>ducting wiresto its emissi<strong>on</strong>, the authors analyzed emissi<strong>on</strong>s from a PCB with c<strong>on</strong>ductingwires directed in the upper directi<strong>on</strong> and the lower directi<strong>on</strong>at the ground edge using the Finite-Difference Time-Domain(FDTD) method. From numerical results, it is shown that in the caseof a c<strong>on</strong>ducting wire c<strong>on</strong>nected to the upper directi<strong>on</strong>, the radiati<strong>on</strong>power is the largest. Moreover, for the positi<strong>on</strong> of a microstrip line,the radiati<strong>on</strong> power is the largest when the distance between themicrostrip line and the wire is small. Further, the experimentalresults of radiati<strong>on</strong> power show the validity of the numerical results.Radiated Emissi<strong>on</strong>s from Proximity Coupled OversizedHeat-SinksDheena Mo<strong>on</strong>gilan, AT&T Bell LaboratoriesRadiated emissi<strong>on</strong> characteristics of oversized heat sinks that have asurface area substantially larger than the top c<strong>on</strong>tact surface of the ICpackage are investigated. The heat sinks are found to radiate at higherlevels when coupled in proximity to the package than the frequenciesc<strong>on</strong>tained within the IC package. In this paper oversizedheat sinks are modeled as proximately coupled patch antennas with ashort-circuited Stub. Patch antenna characteristics such as inputimpedance that varies with the feed positi<strong>on</strong>s, and the patch res<strong>on</strong>ancefrequencies are applied in the analysis of the radiated emissi<strong>on</strong>scharacteristics of oversized heat sinks. Radiated emissi<strong>on</strong> measurmentsfrom a physical proximity coupled patch antenna model and ahighly integrated PCB with oversized heat sink are presented and theresults discussed.Modeling and Measurement of Mutual Coupling Resultingfrom Arbitrary 3-D Structures within Printed Circuit BoardDesignsLeigh Cornock; and Ian Dilworth, — University of EssexWe report measurements and modeling of mutual coupling resultingfrom closely spaced copper plated through holes <strong>on</strong> printed circuitboards (PCB), known as vias. When the magnetic flux generated bya primary system couples with the inductance of a sec<strong>on</strong>dary system,a ‘reflected impedance’ is induced in series with the primary inductance.Our investigati<strong>on</strong> includes practical measurements and <strong>electromagnetic</strong>(EM) modeling using the Transmissi<strong>on</strong> Line Matrix(TLM) code in order to establish the change in coupling and ‘reflectedimpedance’ as a functi<strong>on</strong> of distance between quasi res<strong>on</strong>ant structures.With significant numbers of coupled vias, possible couplingpermutati<strong>on</strong>s are large. We report models for 2, 3, and 4 via coupling,the results from which are extendable to arbitrary 3D structures.PRINTED CIRCUIT BOARD EMC IIPPW Noise Mitigati<strong>on</strong> in Multilayer PCBs by Means ofVirtual Island and/or Array of Shorting ViasAnt<strong>on</strong>io Ciccomancini, CST of AmericaThis paper describes the parallel-plate waveguide (PPW) noise mitigati<strong>on</strong>by means of shorting vias and/or virtual islands. The proposedmethod is already know in literature, nevertheless importantc<strong>on</strong>siderati<strong>on</strong>s are addressed here: 1) the same noise mitigati<strong>on</strong> levelcan be achieved by using <strong>on</strong>ly shorting vias or virtual island in combinati<strong>on</strong>with shorting vias, 2) the noise mitigati<strong>on</strong> is strictly relatedto the number of shorting vias, the positi<strong>on</strong> and the distance fromthe signal via, and 3) the PPW noise suppressi<strong>on</strong> is effective <strong>on</strong>ly ifan array of shorting vias is used. The mitigati<strong>on</strong> level is investigatedboth in the time domain and frequency domain. Different c<strong>on</strong>figurati<strong>on</strong>sare studied and the impact of the power plane withetched slots due to virtual islands <strong>on</strong> the signal quality is also analyzed(TDR and inserti<strong>on</strong> loss).Suppressi<strong>on</strong> Effect of Emissi<strong>on</strong>s from a Printed CircuitBoard Using a C<strong>on</strong>ducting PlateTeruo Tobana; Takayuki Sasamori; and Kohshi Abe, — Akita PrefecturalUniversityFor emissi<strong>on</strong>s caused by the comm<strong>on</strong>-mode current <strong>on</strong> a printedcircuit board (PCB), a suppressi<strong>on</strong> method based <strong>on</strong> the image theoryof placing a c<strong>on</strong>ducting plate under the PCB is presented. Inorder to evaluate the suppressi<strong>on</strong> effect by this method, the radiati<strong>on</strong>power from the PCB is calculated using the FDTD method.The numerical results show that by placing the c<strong>on</strong>ducting platenear the ground side of the PCB, the emissi<strong>on</strong>s from the comm<strong>on</strong>modecurrent are effectively suppressed. Especially, using the c<strong>on</strong>ductingplate with bent sides, it is possible to suppress the emissi<strong>on</strong>sby the small c<strong>on</strong>ducting plate. Moreover, the method ofbending the edges of the PCB is presented and it is shown that alarge suppressi<strong>on</strong> effect is obtained using this method. Further, theexperimental results of a maximum electric field intensity show thevalidity of the numerical results.©<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