This observation is physically consistent, since the crosstalk coupling
is usually higher when the traces are closer (tighter coupling) and are far from the ground plane (field lines spread out and are more likely to interfere with an adjacent circuit).
* Vertical Reference Plane Changes * Nets Crossing Gaps * Net Near Plane Edge * Filter Placement * ICs Over Split Planes * 10 Coupling * Edge Rate * Edge Rate to Period * Exposed Length * Metal Island * Edge Shield * Long Nets * Termination Check * Long Stub * Many Vias * Guard Trace * Diff Pair * Decoupling Cap Placement * Power/Ground Width * Impedance * Differential Impedance * Crosstalk Coupling
The design complexities introduced by higher routing densities and widespread usage of ICs with fast-edge rates make it quite challenging to exhaustively verify a PCB design's electrical performance.
Generally speaking, there are two kinds of unwanted emission: crosstalk coupling and radiative coupling.
The information of keystrokes leaking to the ground line network is caused by crosstalk coupling and radiative coupling.
8:30 to 9:00: Transient Analysis of Crosstalk Coupling
Between High-Speed Carbon Nanotube Interconnects
Alien crosstalk coupling
occurs with respect to both the near end and far end of the installed cabling system.
Topics to be studied include: antennas, the grounding myth, partial and incomplete inductance, intentional and unintentional signals, critical signals, common-mode and differential-mode emissions, crosstalk coupling
, multilevel/cascade crosstalk, guard traces vs.
BoardSim Crosstalk automatically searches entire boards and builds models for regions where crosstalk coupling
between traces can exceed user-defined limits.
FIGURE 11 shows an estimate of the crosstalk coupling
for single-ended traces as a function of separation for a typical set of PCB dimensions.
Alien crosstalk is the exact same phenomenon but the crosstalk coupling
now occurs between wire pairs in different, adjacent cabling links.
The information required to accurately predict the significance of certain types of ALSR crosstalk coupling
is not trivial.
The ITU-T model, presented in a recommendation G.993.5 , is based on the mathematical derivation of crosstalk couplings
between symmetrical pairs in a cable and it also uses pseudorandom values of phase characteristic.