From: Andrew S. <wac...@go...> - 2013-01-23 21:50:45
|
On 20/01/13 17:10, 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 architecting SoC'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. |
From: Frans S. <fra...@gm...> - 2013-01-23 22:03:40
|
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 microstrip lange 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...> het volgende: > On 20/01/13 17:10, 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 architecting SoC'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... > https://lists.sourceforge.net/lists/listinfo/qucs-devel > |
From: mike b. <mbr...@ya...> - 2013-01-24 09:59:19
|
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... ________________________________ From: Frans Schreuder <fra...@gm...> To: Andrew Stevens <wac...@go...>; "quc...@li..." <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...> hetvolgende: > On 20/01/13 17:10, 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... > 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... https://lists.sourceforge.net/lists/listinfo/qucs-devel |
From: Chuck <cmc...@gm...> - 2013-01-24 14:07:11
|
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...> To: Frans Schreuder <fra...@gm...>,Andrew Stevens <wac...@go...>,"quc...@li..." <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... ________________________________ From: Frans Schreuder <fra...@gm...> To: Andrew Stevens <wac...@go...>; "quc...@li..." <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...> hetvolgende: > On 20/01/13 17:10, 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... > 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... 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... https://lists.sourceforge.net/lists/listinfo/qucs-devel |
From: mike b. <mbr...@ya...> - 2013-01-25 13:56:35
|
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... > > >________________________________ > From: Chuck <cmc...@gm...> >To: mbr...@ya...; fra...@gm...; wac...@go...; 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...> >To: Frans Schreuder <fra...@gm...>,Andrew Stevens <wac...@go...>,"quc...@li..." <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... > > >________________________________ >From: Frans Schreuder <fra...@gm...> >To: Andrew Stevens <wac...@go...>; "quc...@li..." <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...> >hetvolgende: > >> On 20/01/13 17:10, 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... >> 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... >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... >https://lists.sourceforge.net/lists/listinfo/qucs-devel > > > |
From: Chuck <cmc...@gm...> - 2013-01-25 16:02:55
|
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 >> >> > > > |
From: Andrew S. <wac...@go...> - 2013-01-24 19:20:26
|
Hi Richard, > The real step control is handled by modifying the delta variable in a do > loop inside the for loop (at the top of which swp->next() is called). If > a time step is rejected, the delta variable is modified and the do loop > run again (but without moving on to the next for loop iteration) and > swp->next() is not called. A scenario where the outer loop would iterate would be when an EXCEPTION_NO_CONVERGENCE 'exception' is raised by the corrector() call. In this case delta is reduced and error (though originally set) reset back to 0 and rejected incremented. (Lines trsolver.cpp:252-282) at which trsolver.cpp:228 triggers a loop continue causing the *next* time-step to be selected trsolver.cpp:220. The Issue probably isn't too noticeable since its associated with convergence problems a user would probably have other issues to worry about. However in a cosimulation context the sweep raster may be be being relied on. Skipping raster points would cause some surprises in the slaved digital simulation! cheers, Andrew |
From: Richard C. <s02...@sm...> - 2013-01-25 09:20:08
|
On 24/01/2013 19:20, Andrew Stevens wrote: > Hi Richard, > > > A scenario where the outer loop would iterate would be > when an EXCEPTION_NO_CONVERGENCE 'exception' is raised > by the corrector() call. In this case delta is reduced and error (though > originally set) > reset back to 0 and rejected incremented. > > (Lines trsolver.cpp:252-282) at which trsolver.cpp:228 triggers a loop > continue causing the > *next* time-step to be selected trsolver.cpp:220. I take it you mean the continue statement 'if (rejected) continue;' on trsolver.cpp:288 (rather than trsolver.cpp:228)? This continue statement (as far as I can see) actually returns us to the start of the inner do loop on trsolver.cpp:228. Therefore we do not pass trsolver.cpp:219 (the outer for loop line) and do not call line trsolver.cpp:220 (which is the line 'time = swp->next ();'). Richard -- The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336. |