Hi sky_of_bj, What's the location of this DECAP? How do you set the two ports to get S21, at two ends of the power net? Thanks, Guobing 2010/7/26, steve weir <weirsi@xxxxxxxxxx>: > Yes, inductance is of an entire loop. For convenience of analysis the > loop is often broken into components. The effective inductance of the > capacitor to the PDN is the loop that includes the interconnect to the > rest of the PDN, ( or at least where you are measuring ), and the > physical capacitor structure. This presentation from my web site > explains the physics. > http://www.ipblox.com/pubs/SVCEMC_Feb_2006/stack_up_vias_pdn_public.pdf > The chart on page 23 should help you. > > Steve. > AAA????? wrote: >> Hi All, >> a power net on hdi board ,I find that the 100nf capacitor 's(only one >> capacitor) resonance frequecy (the capacitor package is 0201)is 38Mhz(test >> S21 by VNA), rather higher than its normal resonance frequecy 18Mhz(if not >> consider the parasitic inductor on the pcb borad). >> >> Does the pcb board impact the capacitor and the esl of the capacitor >> become smaller? >> >> >> Can anybody help me in solving this? >> >> Regards, >> sky_of_bj >> >> >> >> _________________________________________________________________ >> Ò»ÕÅÕÕƬµÄ×԰סª¡ªWindows LiveÕÕƬµÄ¿É°®ÊÓƵ½éÉÜ >> http://windowslivesky.spaces.live.com/blog/cns!5892B6048E2498BD!889.entry >> >> ------------------------------------------------------------------ >> 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 technical documents are available at: >> http://www.si-list.net >> >> List archives are viewable at: >> //www.freelists.org/archives/si-list >> >> Old (prior to June 6, 2001) list archives are viewable at: >> http://www.qsl.net/wb6tpu >> >> >> >> > > > -- > Steve Weir > IPBLOX, LLC > 150 N. Center St. #211 > Reno, NV 89501 > www.ipblox.com > > (775) 299-4236 Business > (866) 675-4630 Toll-free > (707) 780-1951 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 technical documents are available at: > http://www.si-list.net > > List archives are viewable at: > //www.freelists.org/archives/si-list > > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > > > -- Thanks, - Robin (Han, Guobing) TEL: 86-21-61094805 MSN: han_guobing@xxxxxxxxxxx ------------------------------------------------------------------ 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 technical documents are available at: http://www.si-list.net List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu