WRT is working on the 112G rev of a 56-112G test system first using Bullseye2
(50GHz) and now working on the Bullseye 3 rev, 112G (67GHz) for eSilicon.
This connector family is robust (if you grab the coax breakout cable and twist
it hard in different off 90deg axis the S-parameter doesn’t change, for
example), is very good SI, and the Samtec support has been exceptional. The
support included assistance with measurement verification, application
assistance, and the Samtec signal integrity team worked as a 3rd 3D-EM team.
WRT uses 3 teams of 3D-EM optimization, where each team works independently.
Samtec represented one team and WRT had 2 internal teams. Some of the
results were included in a test fixture for 112G web presentation we did for SI
Journal (we can send URL). I can send a pdf of the slides for anyone
interested who is working in this space. To my knowledge, the results will
achieve a new level of SI through 70GHz for ultra-sensitive PAM-4 test
fixtures. The Bullseye HD and 1.85mm VLF style launch connector are the crux
elements in the design.
There has to be a paradigm shift in how connector companies, signal integrity
teams, and their end customers work together. It isn’t 1992 any longer where
the lawyers and top brass make life working together virtually impossible with
nonsensical IP protection and a barrage of barriers. Some of the connector
folks (this is not true for all connector folks) need to dramatically improve
their electrical characterization and 3D EM models. The connector folks are
powerful and dominate compliance committees so it is going to take stiff
competition for things to change. The antiquated applications engineering
model is stuck in the 10G space IMHO (remember when we thought 10G was blazing
fast!).
I would ask prospective vendor for HD interconnects:
1. What electrical characterization was done by your team? Then use IEEE
P370 metrics to evaluate SI.
2. Is that fixture available for us to borrow?
3. What time domain gating was done or fancy post processing?
4. What is connector repeatability channel-to-channel with TDR overlay, skew.
5. What is quality of the total interconnect using fast TDR (2psec) from
coaxial 1.85male connector- cable-HD interconnect.
6. If you twist the connector cable 90degrees off axis does the S-parameters
change (SMP connectors have a big problem with this). This performance is
critical.
7. How good is their 3D EM optimization support, reports, step and dxf file
support? Start with a return loss mask that has a clear S11 goal.
8. What is their model quality? Not convinced an encrypted HFSS model of
actual connector is the right model for these demanding SI apps.
9. Measure TDR of scores of channels and overlay impedance profiles for all
the measurements
10. How good is the mechanical interconnector, bulkhead housing and
associated integrity.
(Any additional inputs above? Please pm me.)
WRT will be presenting at the Penn State Signal Integrity Symposium April 12th
and will be discuss this topic and present more data. For now, maybe
spending the day fly fishing for steelhead on the Nahalem River will help shut
the switch off!
- Al Neves
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx <si-list-bounce@xxxxxxxxxxxxx> On Behalf Of
Hermann Ruckerbauer
Sent: Sunday, March 3, 2019 2:06 AM
To: si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] Re: PCB material extraction
Hello,
just one question on the Ardent compression mount connectors.
So far I knew only the Samtec Bulls eye that looks somehow similar, but I'm not
sure if it would fit the same usage model.
The second one seem to allow higher signal density, but I'm not sue if the
attachement is similar simple.
In case such connectors are needed, I anyhow need to check which one does the
job best..
Are there any more that would do the job for a characterization board ?
Hermann
--
Our next events:
Embedded World 2019: Visit us at Booth 158 in Hall 3
EKH - EyeKnowHow
Signal Quality - Made in Bavaria
Hermann Ruckerbauer
www.EyeKnowHow.de
Hermann.Ruckerbauer@xxxxxxxxxxxxx
Itzlinger Strasse 21a
94469 Deggendorf
Tel.: +49 (0)991 / 29 69 29 05
Mobile: +49 (0)176 / 787 787 77
Fax: +49 (0)3212 / 121 9008
Am 02.03.2019 um 17:57 schrieb Lyndell Asbenson:
Thanks very nice job. Yes the SMAs are problematic I like page 116
been there. The Quicklink looks interesting but the.
I was impressed over your collaboration, something engineers don't
come by easly. -Lyndell
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx
[mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Ching-Chao Huang
Sent: Saturday, March 2, 2019 8:12 AM
To: talented.libran@xxxxxxxxx; 'SI-LIST' <si-list@xxxxxxxxxxxxx>
Subject: [SI-LIST] Re: PCB material extraction
Hi Robert,
See this DesignCon 2019 tutorial on DK/DF extraction:
http://ataitec.com/docs/DK_DF_extraction_tutorial_DesignCon_2019.pdf
Regards,
Ching-Chao Huang
www.ataitec.com
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx
[mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of ;
talented.libran@xxxxxxxxx
Sent: Saturday, March 2, 2019 7:20 AM
To: SI-LIST
Subject: [SI-LIST] PCB material extraction
Hello everyone,
I was trying to model a manufactured rev of a pcb especially at the
2.92mm sma launch area. I took some cross-sections of our existing
test card along with x-ray scans to model accurately the via, antipad and
stackup details.
I see good correlation until certain portion of the model (2.92mm
connector and 8mil drill via in TDR plot). In a 3d field solver I
specify causal frequency dependent djordjevic-sarkar model. But I
cannot get a correlation from the pcb portion (trace breakout) of the design.
Are there any steps or data which could be extracted from existing pcb
to get accurate numbers for dk and df values? Please share your
comments. I have access to 26.5 GHZ VNA, 18ps trise TDR, PLTS software
in addition to 3D field solver. I'm trying to get frequency and time
domain correlation until 20GHZ where IL and RL cross.
Thanks
Robert
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List forum is accessible at:
http://tech.groups.yahoo.com/group/si-list
List archives are viewable at:
//www.freelists.org/archives/si-list
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List forum is accessible at:
http://tech.groups.yahoo.com/group/si-list
List archives are viewable at:
//www.freelists.org/archives/si-list
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List forum is accessible at:
http://tech.groups.yahoo.com/group/si-list
List archives are viewable at:
//www.freelists.org/archives/si-list
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
