From: Chuck <cmc...@gm...> - 2013-01-25 16:02:55
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When I get time, I'll take a look at it. It may be awhile. I just stared a new job in a different city, so I am in the process of getting relocated. Chuck On 1/25/2013 8:56 AM, mike brinson wrote: > Hello Chuck > > Thanks for your email. > > Stefan Jahn implemented the HB version which is currently coded in Qucs. > Stefan is no longer an active member of the Qucs development team. > The Qucs implementation is not complete and is rather unstable - One > problem is its convergence > algorithms are not adequate. The code is well documented by Stefan - > this explains its limitations. > Similarly most of the device models are not implemented for HB analysis. > > My interest is in the modelling - which I am looking at with a view to > improving in the near future. > > if you have the knowledge concerning implementation of HB would you > have a look at the Qucs code, > and if you can, help improve, and stabilise, the current code. > > Thanks for your interest. > > Mike > > > Mike Brinson > > mbr...@ya... > ------------------------------------------------------------------------ > *From:* Chuck <cmc...@gm...> > *To:* mike brinson <mbr...@ya...> > *Sent:* Friday, 25 January 2013, 0:24 > *Subject:* Re: [Qucs-devel] Bug/logic oddity in Transient solver loop > > The basic harmonic balance equation just solves the continuity > equation for charge. > Q, dQ/dV, I, dI/dV all must be continuous. That's the theory > anyway. I have not looked at the QUCS implementation. Who is lead > on the HB simulator? > > Chuck > > > On 1/24/2013 11:44 AM, mike brinson wrote: >> Hello Chuck >> >> I agree for HB we need good continuity in a function , its 1st order >> derivative and higher order >> derivatives. The new BSIM 6 model has just these properties, see >> >> http://www.mos-ak.org/india/presentations/Chauhan_BSIM6_MOS-AK_India12.pdf . >> >> Mike. >> Mike Brinson >> >> mbr...@ya... <mailto:mbr...@ya...> >> ------------------------------------------------------------------------ >> *From:* Chuck <cmc...@gm...> <mailto:cmc...@gm...> >> *To:* mbr...@ya... <mailto:mbr...@ya...>; >> fra...@gm... <mailto:fra...@gm...>; >> wac...@go... <mailto:wac...@go...>; >> quc...@li... >> <mailto:quc...@li...> >> *Sent:* Thursday, 24 January 2013, 14:06 >> *Subject:* Re: [Qucs-devel] Bug/logic oddity in Transient solver loop >> >> HB simulation needs comtimuity in the function & 1st deritive. Models >> need to be well behaved outside off expected ranges. >> >> >> -------- Original message -------- >> Subject: Re: [Qucs-devel] Bug/logic oddity in Transient solver loop >> From: mike brinson <mbr...@ya...> >> <mailto:mbr...@ya...> >> To: Frans Schreuder <fra...@gm...> >> <mailto:fra...@gm...>,Andrew Stevens >> <wac...@go...> >> <mailto:wac...@go...>,"quc...@li..." >> <mailto:quc...@li...> >> <quc...@li...> >> <mailto:quc...@li...> >> CC: >> >> >> Hello Frans and Andrew >> >> The basic Qucs semiconductor device models are similar to those found >> in SPICE. The EKV 2.6 MOS >> model I added around two to three years ago. The same comment >> applies to the MESFET models. All >> the existing models appear to work for DC, AC and TRAN simulation. >> Circuits with convergence problems >> will, of course, fail sometimes. However, one area where there are >> real problems is Harmonic Balance. If a >> model has discontinuities in its I/V or Q characteristics second >> order or higher derivatives HB simulation will >> fail and not complete. My plans at the moment are to add a number of >> new semiconductor device models, starting >> with the latest upgrades to the HICUM models. I have both BSIM 3 and >> BSIM 4 MOS models working with QucsStudio. These >> should port to Qucs without too many problems. However, please note >> the ADMS XML interface is different for >> QucsStudio and Qucs so this could take some time. Once BSIM 6 is >> released to the public domain I will also try and add this to Qucs. >> I am also thinking of adding some basic BJT and MOS models which >> work, hopefully without problems, with HB simulation. >> These should allow those interested in RF and microwave design the >> opportunity to apply HB simulation to a range of active circuits. >> Again, please note HB simulation will also require work as its not >> very stable at the moment. >> >> On the subject of models one area that needs work is the development >> of the microwave models for transient simulation. >> The existing microstrip models, for example, are AC linear models and >> do not operate correctly in the transient time domain. >> >> Lots to keep the new team occupied ! >> >> Best wishes. >> >> Mike >> >> >> Mike Brinson >> >> >> mbr...@ya... <mailto:mbr...@ya...> >> >> >> ________________________________ >> From: Frans Schreuder <fra...@gm...> >> <mailto:fra...@gm...> >> To: Andrew Stevens <wac...@go...> >> <mailto:wac...@go...>; "quc...@li..." >> <mailto:quc...@li...> >> <quc...@li...> >> <mailto:quc...@li...> >> Sent: Wednesday, 23 January 2013, 22:03 >> Subject: Re: [Qucs-devel] Bug/logic oddity in Transient solver loop >> >> Hi Andrew, >> >> That sounds busy! But in order to help you can also do small >> portions, you >> don't need to commit your whole life to it. Anyway if you say you don't >> feel like joining that is ok. >> I also just joined the team. All i know about the mosfet models is that >> some of them work better than others. Especially in transient simulations >> there are often problems. >> The simulator was mainly developed by Stefan Jahn (ela) but he is not >> active anymore. I know something about simulators but not enough to >> create >> completely new models. >> I have joined qucs mainly to get it back to life and back into the major >> linux repositories, for that to happen we needed a qt4 port which i >> made. I >> want to concentrate now on bug fixes and to get it at least as stable as >> the qt3 version, after that i want to learn something about the simulator >> as well. I have hardly touched the simulator (qucs-core) except for the >> microstriplange coupler model which was derived from the coupled >> microstrip lines. >> For the future we are also looking for people who can help improving the >> simulator backend. >> >> Frans >> Op 23 jan. 2013 22:50 schreef "Andrew Stevens" >> <wac...@go...> <mailto:wac...@go...> >> hetvolgende: >> >> > On 20/01/13 17:10, quc...@li... >> <mailto:quc...@li...> wrote: >> > > >> > > Hi Andrew, >> > > >> > > We are now building a new team to get Qucs back on the road, at least >> > > the activity has been boosted. >> > > A couple new people are working on it now (I am also new). >> > > I have to get a little more familiar with the way the simulator >> works, I >> > > have now concentrated on the Qt4 part. >> > > It seems like you know what you are talking about, why don't you >> join us? >> > > >> > > Frans >> > > >> > >> > Hi Frans, >> > >> > Sorry about the delay responding. I've been laid out with an evil cold >> > for a few days. >> > Joining the team sounds fun but with two young kids, a working partner >> > and non-trivial day job I'm not sure I can make any commitments about >> > any kind of sustained contributions. >> > >> > I'm afraid I know only enough about Newton-Raphson solver based circuit >> > simulation and numerical analysis to know that I don't know much at all >> > ;-). I'm a C++ EDA verification/synthesis tooling guy who ended up >> > doing some time architectingSoC's more or less 'by accident'. >> > >> > However, I would like to get a cosimulation interface up and running. >> > >> > Regards, >> > >> > Andrew >> > >> > >> > PS >> > Whats the state of the MOSFET Models in Qucs? Some quick tests with a >> > circuit using a MOSFET to switch a diode-clamped inductive load >> produced >> > some pretty weird behaviour. I can't yet rule out a oops in my >> circuit >> > - if I get a moment I'll try to cross-check both on SIMetrix - but it >> > looked damn strange. >> > >> > Trying the same MOSFET in a flyback converter model that produce >> > beautiful "classical" wave with ideal switches also behaved very >> > strangely with a MOSFET replacing the switch. >> > >> > >> > >> > >> ------------------------------------------------------------------------------ >> > Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, >> > MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current >> > with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft >> > MVPs and experts. ON SALE this month only -- learn more at: >> > http://p.sf.net/sfu/learnnow-d2d >> > _______________________________________________ >> > Qucs-devel mailing list >> > Quc...@li... >> <mailto:Quc...@li...> >> > https://lists.sourceforge.net/lists/listinfo/qucs-devel >> > >> ------------------------------------------------------------------------------ >> Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, >> MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current >> with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft >> MVPs and experts. ON SALE this month only -- learn more at: >> http://p.sf.net/sfu/learnnow-d2d >> _______________________________________________ >> Qucs-devel mailing list >> Quc...@li... >> <mailto:Quc...@li...> >> https://lists.sourceforge.net/lists/listinfo/qucs-devel >> ------------------------------------------------------------------------------ >> Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, >> MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current >> with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft >> MVPs and experts. ON SALE this month only -- learn more at: >> http://p.sf.net/sfu/learnnow-d2d >> _______________________________________________ >> Qucs-devel mailing list >> Quc...@li... >> <mailto:Quc...@li...> >> https://lists.sourceforge.net/lists/listinfo/qucs-devel >> >> > > > |