Hi, to maximize the physical memory usage, you can go to /maxwell/config/ directory, then open the file pref.ini with notepad or wordpad. In the file, add the following: DIRECT_SOLVER MemLimitSoft 131072 (max.=70% of your physical memory, in kilobytes) DIRECT_SOLVER MemLimitHard 131072( max.=120% of your physical memory, in kilobytes) Regards, Xin Xin Wu Ph.D student, University of Maryland, College Park Http://www.wam.umd.edu/~xwu >From: "Chandrasekhar Arun" <achandra@xxxxxxx> >Reply-To: achandra@xxxxxxx >To: <Dan_Swanson@xxxxxxxxxxxx>, ><mike_bihan@xxxxxxxxxxxx>,<si-list@xxxxxxxxxxxxx> >Subject: [SI-LIST] Re: HFSS solution issue >Date: Fri, 24 Jan 2003 11:45:57 +0100 > > >Hello Dan and all HFSS users, > Excellent comments from Dan and it really summarises what every HFSS = >new user needs to know reg. solving his/her model. A few points from my = >experience >1. My primary application with HFSS is solving chip-package = >interconnects and I use a delta-S of 0.005. This number is not = >sacrosanct, but when coverted to dB is -0.043 dB for insertion loss and = >-46 dB for return loss >IL=3D20log10(1-0.005) and RL=3D20log10(0.005) >The key is finding an optimum between solution accuracy and time. I = >expect my structures to have an insertion loss of about 1 dB at 5 GHz = >and it is Ok for me if my HFSS results are 1.043 or 0.957 dB. However if = >you are trying to extract the S-parameters of a low-loss short line, = >maybe this error is too high. However, already to achieve 0.005 eroor I = >have to live with about 25000 tetrahedra and this takes a few hours to = >simulate for 20 points and there is no way I can think of delta-S lower = >than 0.005! >2. If you are usinh HFSS at low frequencies, remembet to Solve Inside = >Metals ! >3. To compare your results with VNA measurements always de-embed and = >re-normalise with 50 ohms > >one question >does anyone know how you can manipulate the amount of memory used by = >HFSS while solving in the RAM and the disk? I have 1GB of RAM, still = >HFSS always swaps some data with the disk. I remember that the deafult = >is 70% RAm and 30% dis, but I do not see this always! >Regards > =20 >Arun Chandrasekhar >PhD Student: RF Packaging =09 >IMEC | MCP/MaRS Group =09 >Phone: +32 16 28 82 28 =09 >Fax: +32 16 28 10 97 =09 >Email: achandra@xxxxxxx <mailto:achandra@xxxxxxx> =09 >Seeds for Tomorrow's World <http://www.imec.be/> =09 > =20 >IMEC, Kapeldreef 75, 3001 Leuven, Belgium | Phone:+32 16 28 12 11 = >Fax:+32 16 22 94 00 | Website: www.imec.be <http://www.imec.be/>=20 > > > >This e-mail and/or its attachments may contain confidential information. = > It is intended solely for the intended addressee(s). >Any use of the information contained herein by other persons is = >prohibited. IMEC vzw does not accept any liability for the contents of = >this e-mail and/or its attachments.=20 > > >-----Original Message----- >From: Swanson, Dan [mailto:Dan_Swanson@xxxxxxxxxxxx] >Sent: Thursday, January 23, 2003 17:23 >To: 'mike_bihan@xxxxxxxxxxxx'; si-list@xxxxxxxxxxxxx >Subject: [SI-LIST] Re: HFSS solution issue > > > > >Bi, Han > >I think you are a little confused on how the solution setup goes. > >Adaptive Single Frequency can be run by itself or it >is the starting point for a Frequency Sweep. > >So you adapt the mesh at some frequency, typically the highest >freq you are interested in. Then you start the frequency sweep >using that adapted mesh. So the mesh is "overkill" for the low >freqs and just right for the high freqs. Knowing this, if you >are trying to cover many octaves in frequency, then maybe >several runs using different adapt freqs is more efficient. > >So in the setup menu you select both the Single Freq Adapt >and the Freq Sweep you want at the same time. The software then >does both. > >If you run a Discreet Sweep, results should be fine. A Fast Sweep >tries to derive the result from the minimum number of discreet=3D20 >freq solutions. Watch out for the both ends of the sweep range >and always check the results at least once with a discreet sweep. >If you ask for a very wide Fast Sweep range, the software often >suggests that you break it up into smaller segments. > >As to number of adapts, that is very tricky. Basically you need >to identify the key parameter in your analysis and figure out >what it takes to get there. For example, I do a lot of resonators. >So I look at convergence of resonant frequency as function of meshing >parameters. Remember this is very general purpose software, you always >know more about you particular problem than the developer or the =3D >software. >You have to use that knowledge to guide the software to the right >solution. > >Using the default settings, the starting mesh in HFSS is very coarse. >I typically set LAMBDA_REFINE_TARGET (system variable) to .02 or .033 >Refinement percentage to 40% (default is 20%). And maybe run 5 to 10 >adapts. I set Delta-S limit to 1e-6, Delta-S achieved is very problem >dependent and does not always imply absolute convergence. Of course >you are looking for a convergence curve that is a nice smooth =3D >parabolla. > >The geometrical resolution in your model will also affect convergence. >I tend to draw cylinders, etc kind of coarse, 8 or 12 sides to a =3D >cylinder. >I do this to speed things up. But sometimes if you make things too =3D >coarse >the convergence curve will oscillate, or you may converge to the wrong >final value. For example, look at impedance of a coax line as a =3D >function >of how many segments you use to define the cylinders. > >All this is in my new book, coming out in May 2003: > >http://www.artechhouse.com/default.asp?Frame=3D3DBook.asp&Book=3D3D1-5805= >3-3=3D >08-6&Cou >ntry=3D3DUS&Continent=3D3DNO&State=3D3DMA > > >Best regards, > > >Dan > >Dan Swanson EMAIL: d.swanson@xxxxxxxx >Forem USA PHONE: 978-834-4085 >37 South Hunt Road FAX: 978-388-7077 >Amesbury, MA 01913 > > > > -----Original Message----- > > From: Bi Han [mailto:mike_bihan@xxxxxxxxxxxx] > > Sent: Thursday, January 23, 2003 10:52 AM > > To: List` Si > > Subject: [SI-LIST] HFSS solution issue > >=3D20 > >=3D20 > >=3D20 > > hi, ansoft guies: > >=3D20 > > There is one simple question about HFSS. > >=3D20 > > Since Adaptive 'Single frequency' analysis will allow users=3D20 > > to setup 'Requested Passes', what number will be suitable? I used 7. > >=3D20 > > However, issues come up! > > The results,obtained by 'Single Frequency', differs greatly=3D20 > > from 'Sweep' analysis=3D20 > >=3D20 > > results? Because of the higher accuracy of 'Single frequency'=3D20 > > analysis, I prefer it than sweep one. (Actually,sweep results=3D20 > > is the Pass 1 results on Single Frequency analysis.) > >=3D20 > > Then, what value does 'sweep' analysis have, with so poor=3D20 > > accuracy, whose mesh will not be refined. In another way, in=3D20 > > which way should we treat the data from 'sweep analysis'? > >=3D20 > > Sincerely, > > Bi, Han > > Sjtu, EMLAB > >=3D20 > >=3D20 > >=3D20 > > --------------------------------- > > Do You Yahoo!? > > =3D >"=3DBF=3DEE=3DBF=3DEE=3DB8=3DDF=3DB9=3DF3=3DB5=3DE4=3DD1=3DC5=3DA3=3DAC=3D= >B5=3DE3=3DBB=3DF7=3DB2=3DCE=3DBC=3DD3=3DC6=3DFB=3D >=3DB3=3DB5=3DB5=3DF7=3DB2=3DE9!" > >=3D20 > > ------------------------------------------------------------------ > > To unsubscribe from si-list: > > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > >=3D20 > > or to administer your membership from a web page, go to: > > //www.freelists.org/webpage/si-list > >=3D20 > > For help: > > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > >=3D20 > > List archives are viewable at: =3D20 > > //www.freelists.org/archives/si-list > > or at our remote archives: > > http://groups.yahoo.com/group/si-list/messages=3D20 > > Old (prior to June 6, 2001) list archives are viewable at: > > http://www.qsl.net/wb6tpu > > =3D20 > >=3D20 >------------------------------------------------------------------ >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 > _________________________________________________________________ The new MSN 8: advanced junk mail protection and 2 months FREE* http://join.msn.com/?page=features/junkmail ------------------------------------------------------------------ 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