Bring a colleague Please Post Free Admission The Santa Clara Valley Chapter of the IEEE EMC Society is presenting on May 9th, at:
Silicon Graphic's Cafe Iris Building 5, 2025 Stierling Court Mountain View CA Dinner: 5:30-7:30pm Presentation: 7:30-9:00pm May IEEE EMC Chapter Meeting Presentation Presenters: Dr. Zorica Pantic-Tanner, Director, School of Engineering, San Francisco State University, Franz Gisin, EMC Manager, Nortel Networks Title: "Radiation from Edge Effects in Printed Circuit Boards (PCBs)" Details --------- Propagating electromagnetic fields are generated whenever charge is accelerated. The polarization, direction, and mode of these fields are dependent on the structure that contains the accelerated charge. In printed circuit boards (PCBs), they include radiation from unwanted parasitic modes associated with tangential (planar) structures such as traces routed on outside layers (microstrip), and traces routed between ground and power planes (striplines). Structures normal to the ground and power planes such as vias also generate surface waves in the dielectric strata directly adjacent to the outside ground/power planes, and radial TEM waves between internal ground and power planes. As these fields propagate outward, they encounter the edge of the PCB. The edge presents a boundary discontinuity, and a portion of the energy in the propagating fields is reflected back into the PCB structure, a portion radiates outward from the edges of the PCB, and, depending on the angle of incidence, a portion also propagates tangentially around the edge of the PCB, exciting natural resonant modes within the PCB that also contribute to the total radiated energy. Using analytical modeling tools such as the Finite Difference Time Domain (FDTD) method and Fast Fourier Transform (FFT) algorithms, one can isolate the time and frequency domain components each of these various propagating modes have on the total radiation from PCB edges, and evaluate the effectiveness of such popular edge radiation minimization techniques as adding a row of closely spaced vias that short together all the ground planes within a multi-layer PCB (fences), and pulling back the power planes from the edges. The presentation includes a brief theoretical analysis of each of the different kinds of propagating modes, the effect the PCB edge has on each mode, and how fences and pulled-back power planes affect the total radiation efficiency from the PCB edge. The presentation also includes several time-domain animations that enhance the physical understanding of how these propagating modes produce radiation along PCB edges. Dr. Zorica Pantic-Tanner is Director of the SFSU School of Engineering, and Director of the SFSU Center for Applied Electromagnetics, a research facility that provides resources for theoretical and experimental studies in applied electromagnetics. She received her B.S., M.S., and Ph.D. degrees in Electrical Engineering from the University of Nish in 1975, 1978, and 1982, respectively. After graduating she became an Assistant Professor and then Associate Professor in the Department of Electronic Engineering at the University of Nish. In 1984 she was awarded a Fulbright Scholarship for postdoctoral research in the area of Applied Electromagnetics with the Electromagnetics & Communications Lab of the University of Illinois at Urbana-Champaign. In 1989 she joined the School of Engineering at San Francisco State University. Dr. Pantic-Tanner's research and teaching interests are in the areas of Electromagnetic Field Theory, Applied Electromagnetics and Electromagnetic Compatibility (EMC). She has published over 50 conference and journal papers in these areas. Dr. Pantic-Tanner is Chair of the Santa Clara Valley Chapter of the IEEE EMC Society, a member of the IEEE EMC Society Education Committee, and Vice-Chair of the IEEE EMC Society Technical Committee TC-9 on Computational Electromagnetics. Under the IEEE EMC Society sponsorship, she has also developed and taught several EMC courses. Franz Gisin is EMC Manager at Nortel Networks. He received his B.S. degree in electrical engineering from the University of Idaho in 1972, and his M.S. degree in Applied Mathematics from the University of Santa Clara in 1986. Franz has been active in the EMC community for over 25 years, and has published numerous papers ranging from measurement uncertainties associated with 1/R extrapolation on OATS to mechanisms of common mode radiation from PCBs with attached cables. He is a past EMC Society Distinguished Lecturer and a past member of the EMC Society Board of Directors. Currently he is steering committee chair of the 2004 IEEE International Symposium on Electromagnetic Compatibility. He also teaches electromagnetics (on a part-time basis) at SFSU. ===== Best Regards Hans Mellberg EMC Consultant __________________________________________________ Do You Yahoo!? Send instant messages & get email alerts with Yahoo! Messenger. http://im.yahoo.com/ **** To unsubscribe from si-list or si-list-digest: send e-mail to [email protected]. In the BODY of message put: UNSUBSCRIBE si-list or UNSUBSCRIBE si-list-digest, for more help, put HELP. si-list archives are accessible at http://www.qsl.net/wb6tpu ****
