John, The formula on page 81 of High Speed Digital System Design is correct (with the 0.03(H/W) in the bottom of the ground resistance equation). If memory serves, the error in the example on page 89 was corrected in a later printing, however, I will double check. - Steve Hall -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of John Phillips Sent: Wednesday, February 25, 2004 2:29 AM To: si list Subject: [SI-LIST] Errata list for High-Speed Digital System Design: A Handbook of Interconnect Theory and Design Practices In the Stephen H. Hall et all book, on page 81 there are some formula=20 for the AC resistance of microstrip derived through conformal mapping,=20 in particular the formula for the ground resistance has terms for W/H on the top of the division and 0.03H/W on the bottom. However in the=20 example on page 89, the top term has become '1' when W/H=3D0.5 and the=20 bottom term 0.03H/W has become 0.03*0.5 when the term H/W =3D2. I do not have access to the source document (Foundations for Microwave=20 Engineering, Robert Collins) so I was wondering if anybody can confirm=20 which is the correct formula. Best Regards John Phillips --=20 John Phillips Signal Integrity Engineer Sun Microsystems Ltd Tel: +44 (0)1252 421120 Sparc House, Guillemont Park Fax: +44 (0)1252 421658 Minley Road, Blackwater, Surrey, GU17 9QC ------------------------------------------------------------------ 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.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 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