The choice of how big to make the subsections is entirely dependent on the
"electrical size" of the interconnect and can be directly related to the
risetime of the signals. The rule of thumb of 10 time samples per risetime
translates into something like a small fraction of a wavelength of a fifth
harmonic of the fundamental. Those of us with a background in fields know
this corresponds to a "electrically small" object in the frequency domain.
Measurements directly compared to theory shows this to be an excellent
approach. On the cautionary side, one does not want to over sample the
connector. More is not always better since the Green's functions describing
the connector may not converge well of the subsection length is too short.
The rule of thumb stated above works for most field simulators and has the
theoretical basis for being correct.
| NORTH EAST SYSTEMS ASSOCIATES, INC. |
| ------------------------------------- |
| "High Performance Engineering & Design" |
| Dr. Ed Sayre e-mail: firstname.lastname@example.org |
| NESA, Inc. http://www.nesa.com/ |
| 636 Great Road Tel +1.508.897-8787 |
| Stow, MA 01775 USA Fax +1.508.897-5359 |