IEEE EMC Society

Two New Distinguished Lecturers for 2009


Sergiu Radu has been at Sun Microsystems for over ten years, and has increased EMC design commonality across Sun’s product lines by writing and maintaining the company’s EMC design best practices documents, through presentations and seminars. He has increased the awareness about EMC issues in new areas for Sun, such as chips and packages and has obtained patents for some of the new solutions used. He was involved in the first research at Sun on board stitching, on heatsink grounding, on the effect of coating on the EMI performance of the chassis, on the effect of internal compartmentalization of the chassis, on the generalized use of a unified grounding structure (as opposed to the I/O grounding islands), and many other initiatives, all these being now standard design practices at Sun and in the industry.
With a strong background in both electromagnetics and circuits, and with a solid experience in research, he was involved not only in the EMC design of a very large number of Sun projects (60+ products, 250+ boards), but he was also actively involved in the IEEE EMC Society through publications, in collaborative research with universities and in internal research leading to patents, publications, internal reports and better solutions for Sun’s products.

Sergiu’s presentation topics include:
1. Engineering Aspects of Electromagnetic Shielding
All electronic equipment uses some type of shielding, and from a theoretical point of view, electromagnetic shielding is among the difficult areas of EMC. The lecture introduces basic shielding concepts, insisting on their practical limitations, and presents the typical engineering problems associated with shielding. Among the aspects discussed are the materials used for shielding, chassis resonances, shielding integrity problems (seams, joints, apertures, perf patterns), aperture coupling and a shield’s grounding.

2. An Overview of Chip Level EMC Problems
The CPUs and the VLSI chips are the primary sources of electromagnetic noise in all electronic equipment. Reducing the electromagnetic noise at the source level is usually the best and the most economical solution. The lecture presents typical interference mechanisms associated with CPU/VLSI, as well as mitigation methods at die-level and package level. Among the aspects discussed are some power distribution issues, on-die decoupling, package capacitors, routing aspects, the impact of back-bias and forward-bias, and the impact of die-shrinks on the EMI performance of the VLSI chips.
3. Engineering Aspects of PCB Level EMC Design
PCB design is a complex cooperation between electrical, mechanical, thermal, SI, PI and EMC design. In a practical design, the EMC design engineer has to make trade-offs and understand the relative impact of different design choices. The lecture is an overview of the typical PCB design aspects and their role for EMC performance. Among the aspects discussed are placement, stack-up, routing, decoupling, and grounding aspects. The design of the I/O ports, in order to pass the emissions and immunity tests, is also discussed in greater detail.

Ji Chen worked in Motorola’s wireless handset division before joining the University of Houston in 2001. During the past 15 years, he has mainly worked on the modeling, simulation, and most recently, the measurement of electromagnetic field interaction with human subjects for various applications.

Ji’s presentation topics include:
1. EMC/EMI Issues in Biomedical Engineering
For this topic he will discuss the interactions between electromagnetic devices and biomedical systems. In particular, he will discuss electromagnetic devices such as walk-through metal detectors and the MRI RF coil in human subjects and implanted devices.
2. EMC/EMI in Wireless Communications
SAR and board-level electromagnetic modeling will be discussed in this presentation.
3. Developing Nano-scale Structures for EMC/EMI
In this presentation, he will discuss the modeling and development of micro-leveled periodic structures for EMC applications.