I've done a fair amount of work in 3D EM with port boundaries, because I do a
lot of simulations involving probes. Most of the time the solvers do a decent
job if you follow the recommendations, but sometimes it is a real challenge
when the fields aren't going to be well behaved at the port location you want,
just like in real life. That's when you need to take real care, and use
deembedding. While the solvers have rudimentary port deembedding, I've stumped
them before when doing a simulation that had differential and common
propagation modes of mismatched impedance. In that case, I got around it by
building a "probe" into the simulation between the port and the DUT, and doing
a SOL(T) calibration on it in the simulator to find the S parameters of the
probe without the DUT. Then I deembedded the probe after doing the simulation
of the probe+DUT. This got around the inability of the solver to account for
even and odd mode impedance issues when deembedding the port.
Regards,
Josiah Bartlett
Tektronix
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On ;
Behalf Of Scott McMorrow
Sent: Monday, May 02, 2016 9:02 AM
To: Alfred P. Neves
Cc: si-list
Subject: [SI-LIST] Re: De-embedding
I don't know about "folks", but I don't. If someone has problems with port
boundaries, then they don't know how to set up solver or measurement
accurately. However, that is based upon years and years of previous
measurement de-embedding and solver correlation work.
Scott McMorrow
R&D Consultant
Teraspeed Consulting - A Division of Samtec
16 Stormy Brook Rd
Falmouth, ME 04105
(401) 284-1827 Business
http://www.teraspeed.com
On Mon, May 2, 2016 at 11:53 AM, Alfred P. Neves <al@xxxxxxxxxxxxxxxxx>
wrote:
Good one. So folks don’t have issues with port boundaries when using
the solver?
*Products for the Signal Integrity Practitioner*
*Alfred P. Neves*
Chief Technologist
Office: 503-679-2429
*www.wildrivertech.com* <http://www.wildrivertech.com/>
*2015 Best In Design&Test Finalist*
On May 2, 2016, at 8:05 AM, Scott McMorrow <scott@xxxxxxxxxxxxx> wrote:
De-embedding is for wimps.
I just press the button on my solver and wait for the answer to pop out.
scott
Scott McMorrow
R&D Consultant
Teraspeed Consulting - A Division of Samtec
16 Stormy Brook Rd
Falmouth, ME 04105
(401) 284-1827 Business
http://www.teraspeed.com
On Mon, May 2, 2016 at 11:01 AM, Alfred P. Neves
<al@xxxxxxxxxxxxxxxxx>
wrote:
I noticed something not too positive this AM, maybe it is spring
fever… One of the biggest and nastiest issues signal integrity and high speed
interconnects folks have to deal with is de-embedding issues. IMHO, the
GMS method of de-embedding, as developed by Simberian Inc, is a key
advance in SI technology.
There are only 32 views on Youtube for this video, really? Reasonable
cost solution, extracts the material properties, scalable reference plan, 2
easy measurements, causal, passive… and only 32 views? The presentation
presents theory and measurement-simulation results as well. A key issue
with de-embedding is a lot of folks blame the algorithm when their
S-parameters are less than stellar quality (they are junk). We also use
Simbeor to also test our S-parameters which directly compliments the method.
https://youtu.be/QTJDz1a0LPA ;<https://youtu.be/QTJDz1a0LPA>
- Al Neves
Products for the Signal Integrity Practitioner
Alfred P. Neves
Chief Technologist
Office: 503-679-2429
www.wildrivertech.com <http://www.wildrivertech.com/>
2015 Best In Design&Test Finalist
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