Hi, Ray: I think it is possible some off diagonal capacitances can be negative. However, if most of them are negative, I believe it must be from numerical error or incorrect extraction setup. In my experience, the capacitance between adjacent lines should never be negative. Regards, --------------------------------------------------------------------------- Jian-X. Zheng, Ph.D. Zeland Software, Inc., 48890 Milmont Dr. 105D, Fremont, CA 94538, U.S.A. Tel: 510-623-7162, Fax: 510-623-7135, Web: http://www.zeland.com --------------------------------------------------------------------------- -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of Ray Anderson Sent: Friday, August 31, 2001 10:08 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] non-negative off diagonal capacitive matrix elements ?? I've just extracted the RLGC matrices for 5 coupled striplines using Apsimtech RLGC. As expected, the diagonal elements of the capacitive matrix are positive capacitance values. All the off-diagonal elements are negative EXCEPT one. Is this correct. It has been a while since I've thought about this, but I was under the impression the capacitive off diag element were all negative. Anyone know for sure ?? The element in column 1 row 5 is the one I question: 3.1600e-15 -4.9360e-16 3.2540e-15 -2.0080e-17 -4.8990e-16 3.2540e-15 -1.3380e-18 -1.9820e-17 -4.8990e-16 3.2540e-15 3.1280e-20 -1.3380e-18 -2.0080e-17 -4.9360e-16 3.1600e-15 -Ray ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field 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 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