I would contact some of the big laminate makers: http://www.isolalaminatesystems.com [1] http://www.parknelco.com/parknelco/ product.htm[2] http://www.rogers-corp.com http://www.ge.com/electromaterials[4] http://www.taconic-add.com/ Greg Beck VP Sales &Marketing Optimum Design Associates-PCB Layout &Engineering p 925.551.4155 x109 c 408.515.1070 www.optimumdesign.com[6] >Transmission line gurus and people who love dielectrics-- >I am trying to figure out the conductivity of a dielectric. >I have an equation that gives me: >tanD = 1/(2*pi*Freq*Er*rd) where rd is the resistivity of the dielectric >I assume that 1/rd is the conductivity of the dielectric. Is that an >erroneous assumption? >That gives me the equation: >conductivity of dielectric = 2*pi*Freq*Er*tanD >This second equation makes sense to me in that increasing your frequency >increases the dielectric conductivity, causing more "leakage" of your >transmitted energy. However, using this equation, that would indicate that >the conductivity of a dielectric with Er=4 and tanD=0.02 would have a >conductivity approaching that of copper at 100MHz. Now that does not make >sense. >Is there a such thing as non-frequency-dependent conductivity of a >dielectric? How would I obtain such a number? >Is there something else I am missing? >Any guidance would be greatly appreciated. Thanks. >--Pat >------------------------------------------------------------------ >To unsubscribe from si-list: >si-list-request@xxxxxxxxxxxxx[7] with 'unsubscribe' in the Subject field >or to administer your membership from a web page, go to: >//www.freelists.org/webpag e/si-list[8] >For help: >si-list-request@xxxxxxxxxxxxx[9] with 'help' in the Subject field >List archives are viewable at: >//www.freelists.org/archives/s i-list[10] >or at our remote archives: >http://groups.yahoo.com/group/si-li st/messages[11] >Old (prior to June 6, 2001) list archives are viewable at: >http://www.qsl.net/wb6tpu[12] > --- Links --- 1 http://www.isolalaminatesystems.com 2 http://www.parknelco.com/parknelco/product.htm 3 http://www.rogers-corp.com 4 http://www.ge.com/electromaterials 5 http://www.taconic-add.com/ 6 http://www.optimumdesign.com 7 mailto:si-list-request@xxxxxxxxxxxxx 8 //www.freelists.org/webpage/si-list 9 mailto:si-list-request@xxxxxxxxxxxxx 10 //www.freelists.org/archives/si-list 11 http://groups.yahoo.com/group/si-list/messages 12 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