Pete, Ozgur, et. al, That's the right formula, but the trick is in actually knowing what the loss tangent is. Vendor data for standard formulations (FR40X, GTEK, Rogers, etc.)can be quite divergent from TDR derived permittivity (then up scaling the permittivty to the frequency of operation), and fitting the loss tangent to the dielectric portion of the total measured loss - Vout/Vin (dB). Anyone know of any good texts or literature sources on the subject? Ken -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of Ozgur Misman Sent: Thursday, November 01, 2001 9:38 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: Loss tangent and Dielectric conductance Actually formula do exist, I must have missed the capacitance in tmy previous E-mail let me rewrite it as Gd=2*pi*f *tand*C (capacitance) C=Er*Co Co= Eo A/d Mick is right in saying that the dielectric loss is a property of the material and conductance depends on the circuit as well. That link is in the capacitance term. The formula is derived assuming a resistance in parallel with capaciatance.and conductance is defined as 1/resistance. Hope this clarifies Ozgur Misman ---------------------- Forwarded by Ozgur Misman/CHAZ/AAWW on 11/01/2001 09:34 AM --------------------------- 11/01/2001 08:51 AM Ozgur Misman - Chandler - 5080 Sr Engineer 01 We've Just Begun To: plaflamm@xxxxxxxx cc: si-list@xxxxxxxxxxxxx Subject: Re: [SI-LIST] Loss tangent and Dielectric conductance (Document link: Ozgur Misman) Hi Peter, I think the for mula is : Gd (conductance)=2*pi*frequency*tand(loss tangent)* Eo (permittivity of the free space;8.854e-12f/m)* dielectric constant;Er Ozgur Misman Amkor Technology Peter LaFlamme <plaflamm@xxxxxxxx>@freelists.org on 11/01/2001 06:45:13 AM Please respond to plaflamm@xxxxxxxx Sent by: si-list-bounce@xxxxxxxxxxxxx To: si-list <si-list@xxxxxxxxxxxxx> cc: Subject: [SI-LIST] Loss tangent and Dielectric conductance Hi SI Folks, I would like to know the relationship between Loss Tangent and Dielectric loss. In other words, If I know the "loss tangent" at a given frequency for a particular dielectric what is the formula to convert this into the Dielectric conductance(Gd) ? Thanks, Peter -- Peter LaFlamme Applied Micro Circuits Corp. Staff System Applications Engineer 200 Minuteman Rd, 3rd Floor Andover, MA 01810 978-247-8470 phone 978-623-0055 Fax ------------------------------------------------------------------ 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 ------------------------------------------------------------------ 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