One hundred million volts, more or less. That is the potential that is developed as roiling masses of air and water and ice molecules furiously swap electrons during a thunderstorm. Charge separation, caused by the friction in the air, related to the mechanism of static built up by rubbing balloon on cat, fills the atmosphere with pockets of ions–positive and negative. As the voltages build, the normally-insulating air molecules stress and disassociate and filaments of current crackle across the sky, releasing mega-joules of energy in each stroke. The supersonic expansion of the ionized air along the stroke path, boiled to a plasma, cracks in a sonic boom, rolling across the sky as thunder.
Equivalent Transmission-Line Model for Vias Connected to Striplines in Multilayer Print Circuit Boards
Each year the IEEE Electromagnetic Compatibility Society sponsors a Best Student Paper competition as part of the IEEE International Symposium on EMC. The contest is administered by the Educational and Student Activities Committee (ESAC) of the Society. For the 2010 Symposium 33 student papers were submitted, the largest number in recent memory. An ESAC panel reviewed and ranked the submissions based on technical contribution, accuracy, and clarity. It always proves to be a challenge to select a single winner from the many fine papers covering many diverse aspects of EMC that are received. The paper selected for 2010 use modal decomposition to derive a transmission line model for printed circuit board vias that can be implemented in circuit simulators. The new model has a significantly faster computation time than that of a full-wave simulator while giving results that are in good agreement. The practical benefit is an improved facility for of the design and optimization of high speed digital circuit boards for both signal integrity and EMC compliance.
The electronics industry is terribly confused by the term Class 0. Particularly when it comes to electrostatic discharge (ESD) device sensitivity and how the term applies to factory controls designed to mitigate ESD. The confusion manifests itself through the many companies and engineers seeking direction on how to “become qualified to handle Class 0 devices.” They are seeking this information because their equally confused customers have imposed requirements on them to meet this mythical level of performance. Not only is Class 0 as a factory level of performance a contrived ideal, it is not a realistic or useful goal. Our purpose here is to explain reality and what is necessary for understanding device ESD sensitivity and establishing control.
The photovoltaic (PV) industry has experienced incredibly fast transformation after year 2000 as a result of extraordinary technology breakthroughs, from the material level up to large-scale module manufacturing.
With the PV industry expected to grow consistently in the coming years, two main questions are capturing the attention among market operators:
- What constitutes a “good quality” module?
- How “reliable” will it be in the field?