[SI-LIST] FW: Re: Question related to HFSS: Zpi, Zpv, Zvi difference

From: "Fasig, Jonathan L." <fasig.jonathan@xxxxxxxx>
To: si-list@xxxxxxxxxxxxx
Date: Wed, 12 Feb 2003 15:12:34 -0600
Hmmm.  I thought the si-list was an open forum for exchange of technical
information, not just an extension of somebody's license manager.  I was
really disappointed to see this thread get shut down before being addressed,
especially since I already paid my HFSS maintenance fee and called the Apps
Engineer (last week) and listened politely while he read me the brief text
on Characteristic Impedance from the online HFSS Technical Notes, which I
had already seen.  In addition, I found the cited reference (Bianco et al,
"Some considerations about the Frequency Dependency of the Characteristic
Impedance of Uniform Microstrips," IEEE Transactions on Microwave Theory and
Techniques, Vol.MTT-26 No.3, March 1978) to be particularly uninsightful
except for the observations that "it must be stressed that slightly
different definitions ... yield strongly different behaviors" and "the above
results show that particular care has to be taken both in computer
calculations and in interpretation of experimental data to avoid confusion."
This ambiguity is further highlighted by Getsinger ("Microstrip
Characteristic Impedance" IEEE Transactions on Microwave Theory and
Techniques, Vol.MTT-27, No.4, April 1979) who opens with "Bianco et al [1]
have recently defined microstrip characteristic impedance in five ways,
based on three definitions of voltage and one of current.  They find that
the different impedances do not have the same functional dependence on
frequency.  Since they do not discuss the merits of the differing
definitions, the reader may assume that all are equally valid
representations of microstrip characteristic impedance."  I was unable to
locate a copy of the second cited reference, Kuester et al,
"Frequency-Dependent Definitions of Microstrip Characteristic Impedance"
from the 1980 International URSI Symposium on Electromagnetic Waves, so I
don't know if it clarifies this mater or not.

So the question stands:  How does one decide which impedance definition to
use?  If anyone understands this then I'd invite them to discuss it, via the
si-list or direct, and I can send them my HFSS license file or whatever it
takes to show that nobody's support revenue is being undermined.  

Of course, all this would be unnecessary if the HFSS documentation explained
it clearly to begin with.

Sincerely,
Jonathan Fasig


-----Original Message-----
From: Grasso, Charles [mailto:Charles.Grasso@xxxxxxxxxxxx] 
Sent: Wednesday, February 12, 2003 12:00 PM
To: 'mike_bihan@xxxxxxxxxxxx'; List` Si
Subject: [SI-LIST] Re: Question related to HFSS: Zpi, Zpv, Zvi difference



Ok OK I'm gonna play the bad guy here.
I would encourage the folks on the SI-List
that use HFSS and (I assume) pay their
maintenance fees- NOT to answer this type
of technical question.

Let me explain why.
As a former Ansoft AE I have some insight
into the costs involved in technical software
support.=20

Ansoft - as do other EM Simulation companies
employ Apps Engineers to answers exactly
this kind of customer question. The companies
that pay their maintenance fees get access to =20
Apps Engineers and software upgrades. The=20
maintainence fees also help fund the support
function. So although its jolly tempting
to display one's  ability with a esoteric
EM tool - I suggest that this undermines=20
the support process and should not be=20
encouraged in this forum.

Best Regards
Charles Grasso
Senior Compliance Engineer
Echostar Communications Corp.
Tel:  303-706-5467
Fax: 303-799-6222
Cell: 303-204-2974
Email: charles.grasso@xxxxxxxxxxxx; =20
Email Alternate: chasgrasso@xxxxxxxx
=20


-----Original Message-----
From: Bi Han [mailto:mike_bihan@xxxxxxxxxxxx]=20
Sent: Wednesday, February 12, 2003 9:47 AM
To: List` Si
Subject: [SI-LIST] Question related to HFSS: Zpi, Zpv, Zvi difference



Can any people tell me the difference between the three kinds of=20
characteristic impedance:   Zpi, Zpv, Zvi.

Manual had given out the definition of these parameters.
Why I ask this question is that one HFSS simulation gives out very =
different

Zpi, Zpv, Zvi results. And Zpv is very close to 2D simulation result.

The case is a CPW line. The results is that Zpi=3D296 Zpv=3D77 = Zvi=3D155.
Why?

Thanks! I need youe xp very much indeed!



Bi,Hai         =20

SJTU, Emlab

=20

=20



---------------------------------
Do You Yahoo!?
"=D1=C5=BB=A2=BD=DA=C8=D5=B4=F3=D7=AA=C5=CC=BE=AA=CF=B2=B2=BB=B6=CF =
=BF=EC=C0=D6=BD=DA=C8=D5=BA=C3=C0=F1=C1=AC=C1=AC!"

------------------------------------------------------------------
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 archives are viewable at:    =20
                //www.freelists.org/archives/si-list
or at our remote archives:
                http://groups.yahoo.com/group/si-list/messages=20
Old (prior to June 6, 2001) list archives are viewable at:
                http://www.qsl.net/wb6tpu
 =20
------------------------------------------------------------------
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 archives are viewable at:     
                //www.freelists.org/archives/si-list
or at our remote archives:
                http://groups.yahoo.com/group/si-list/messages 
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 archives are viewable at:     
                //www.freelists.org/archives/si-list
or at our remote archives:
                http://groups.yahoo.com/group/si-list/messages 
Old (prior to June 6, 2001) list archives are viewable at:
                http://www.qsl.net/wb6tpu
Follow-Ups:
- [SI-LIST] Re: FW: Re: Question related to HFSS: Zpi, Zpv, Zvi difference
  - From: Richard A. Schumacher
[SI-LIST] FW: Re: Question related to HFSS: Zpi, Zpv, Zvi difference

Other related posts:
