Platform Interference in Wireless Systems

1. IntroductionDescribing the problemThe Radio ChannelPlatform emissions impact on a radio receiverPlatform to radio isolation requirementsPlatform RF snapshots3 meter measurementsPlatform RF as seen at the radio front endBroad-band measurements in the near fieldDesktop and notebook platformsSmall form factor platformsSystem components as noise sourcesPlatform RFI sources- Summing it upSection 2: Platform Signals2. The Structure of SignalsHarmonic variation with timeSignal AsymmetryVariation with duty cycleNon-repetitive signalsSpread spectrum clocksData sequences as signalsThe impact of equalizationPlatform display symbolsThe spectrum of complex symbol sequencesTime structure of symbolsComparison of PRBS, clock and symbol sequences3. Analysis of SymbolsOrdering finite symbol sets for RFIWireless performance in the presence of display symbolsMeasuring interference impactAnalysis of differential symbolsSignal structure jitter and the impact on EMI and RFISection 3: Measurement and Models4. Measurement MethodsMeasurement methods, near field scanningFields in dielectricsLocating system sources of interferenceNear field scans of clock ICsEnergy flow in the near field and the transition to the far fieldBroad-band measurements with a horn antennaMeasurements with the GTEM cellFar field measurements using anechoic chambersReverberation chambers5. ElectromagneticsElectromagnetic unitsMaxwell’s equations for the static conditionMaxwell’s equations for the time varying conditionThe electric scalar potentialThe magnetic scalar potentialRadiation mechanisms6. Analytical ModelsThe elementary electric dipoleThe field impedance of the electric dipoleThe extended dipole modelMeasured near fields over siliconBuilding a model of the radiation surface of multiple sourcesThe magnetic dipoleBuilding system models using PCI ExpressComparing model and measurement7. Connectors, cables and power planesPower Distribution Radiated EmissionsFurther investigations with various power topologiesChapter SummarySection 4: Mitigation Techniques8. Passive TechniquesIntroductionPassive MitigationShieldingAbsorbersLayout9. Active MitigationFrequency Planning Controlling Frequency ContentRadio ImprovementsAppendix A: Appendix to Chapter 2Appendix B: Appendix to Chapter 3References