Dave,

I interpersed some comment below.
I'm assuming RF freqs throughout ...

Dave Schaefer wrote:
>
> I'm looking for information regarding SPLIT GROUND PLANES.
>
> Experts on grounding, EMI, EMC are teaching that gaps in ground planes
> create serious problems.

This is not *entirely* true.

Gaps ***IN*** ground planes MAY or MAY NOT cause problems.
Case in point, there's a technique in EMI PCB design called "mouting".
I reccomend it as often as possible to REDUCE noise.  But, it has to
be done correctly or it will really screw things up.  On the other hand,
running controlled impedence traces across the gap in a ground plane
will cause the impedence to change at that point possibly causing
reflections *depending upon the frequency*.

Gaps ***BETWEEN*** ground planes also may or may not cause problems.
If you're referencing traces to one plane, then cross over
to another, your gap will cause a reflection, your impedence
for the trace will be okey, but the return path for the signal
is now on another power return.  Not good to do under certain
circumstances.

> Component manufacturers, however, continue to
> recommend placing gaps under components (such as A/D's and D/A's).

Not sure about this one.

> Can anyone:
>
> - point me in the direction of theoretical reference material

"Digital Design for Interference Specifications" by Kenneth Keenan.
This book really started it all with pcb design techniques for EMI.
Get the book from Dr. Keenan's own company The Keenan Corp.
Very highly reccomend.  The man is a genius out of his own time.

"Noise Reduction Techniques in Electronic Systems" by Henry Ott
for introductory EMI system level/design level stuff.
Highly reccomend.

"High-Speed Digital Design" by Howard Johnson and Martin Graham
but be sure to understand exactly what the reasons are for
doing what they reccomend.

> - relate their experiences / practices

I go design by design.  No overall practice fits all.

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