RE: [SI-LIST] : Effective Dielectric

Andrew Ingraham (Andrew.Ingraham@digital.com)
Tue, 24 Mar 1998 16:55:12 -0500

As you may have guessed from the big difference between replies, we
don't have a clear picture of your problem.

Do you have a signal trace sandwiched between the two dielectric layers,
which is then sandwiched between planes? This is similar to microstrip
or surface-layer etch.

Or are the two dielectric layers both to one side of the signal trace?

Either way, the exact answer depends on the dimensions.

Regards,
Andy

> I have a question regarding the effective dielectric of two layered
> materials (such as ceramics, etc.). For example, say I have two
materials
> with dielectric constants of 4 and 7. When a signal passes through
these
> two materials, what is the effective or total dielectric constant that
it
> sees. Any help on this matter is greatly appreciated.