Chand: I think it is more a matter of making sure that the bandwidth you are truly interested in is all that you are asking for with the fast frequency sweep. I would do the fast frquency sweep, and then double check key frequencies by running these key frequencies explicitly (i.e. no fast frequency sweep). Mike=20 -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of kundanchand chand Sent: Saturday, October 15, 2005 6:14 PM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: Problem with HFSS 9 Mike Thanks for the info. For fast sweep, what should be chosen as the solution frequency in the set up:=20 center frequency or maximum frequency of the range. Mike Heimlich <mike@xxxxxxxxxxx> wrote: Chand: So called "fast frequency sweeps" are approximation techniques which use data from within the underlying computational method to "predict" the response at other frequencies. So over the broader bandwidth simulation it is doing more interpolation for your 200MHz BW of interest. Also, if by "impedance" you have a significant I2R loss, you may not be getting accurate results if you do not use enough volume meshing in the metal. You may want to try one of the 3D planar methods, like closed-boundary method of moments (Sonnet or EMSight), which allows you to determine the upper bound of the error by halving the mesh size....see anyone of the papers by J. Rautio about this. -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of kundanchand chand Sent: Saturday, October 15, 2005 1:44 PM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Problem with HFSS 9 Hi everyone I am trying to get impedance plots for a power bus board using HFSS 9. I performed simulations on the same geometry using the following 2 frequency ranges: 1) start =3D 1 MHz, stop =3D 200 MHz, step =3D 1 MHz 2) start =3D 1 MHz, stop =3D 1 GHz, step =3D 1 MHz But the impedance plots (1 MHz - 200 MHz) are different for both cases.=20 Can anyone let me know the reason for that. I am using "fast" frequency sweep. Thanks --------------------------------- Yahoo! India Matrimony: Find your partner online. ------------------------------------------------------------------ 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org 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 Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu =09 --------------------------------- Yahoo! India Matrimony: Find your partner now. ------------------------------------------------------------------ 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org 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 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org 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