Jun Fan

Bio: Jun Fan is an academic researcher from Missouri University of Science and Technology. The author has contributed to research in topics: Equivalent circuit & Printed circuit board. The author has an hindex of 36, co-authored 482 publications receiving 5641 citations. Previous affiliations of Jun Fan include Ulsan National Institute of Science and Technology & University of Missouri.

Differential integrated crosstalk noise (ICN) reduction among multiple differential BGA and Via pairs by using design of experiments (DoE) method

Abstract: The integrated crosstalk noise (ICN) has been wildly used as an alternative to the insertion crosstalk ratio (ICR) for channel crosstalk evaluation in the IEEE 802.3ba standard. In this work, a differential ICN analysis is performed for several configurations of package-to-PCB transitions. Using the design of experiment (DoE) statistical method, differential ICN is quickly estimated for various input factors such as pin mapping, physical dimensions, and level of shielding. Optimization guide line is proposed to maintain the tradeoff among the differential ICN, design space, and manufacturing cost.

On the possibility to detect and visualize electromagnetic coupling paths

Abstract: Out of the source - coupling path - victim concept, the coupling path is the most difficult to identify. This paper discusses several possible methods to detect and visualize electromagnetic coupling paths in EMC problems. The authors do not have a ready-made solution and hope this paper could inspire others to join us in the search of methods for the detection and visualization of coupling paths.

Hybrid method used to model via transitions

Abstract: A hybrid approach to solve via impedance and model via transitions is presented in the paper. The method is a combination of via-plane capacitance extraction and the impedance matrices calculation of parallel plane pair. A new formulation of the integral equation method for axially symmetric geometry is used for the capacitance extraction. The method is validated with other model results.

3D Modeling and Circuit Model Extraction of Vias in Multilayer Printed Circuit Boards

Abstract: The analysis of vias in multilayered geometries helps to improve the modeling of PCB’s and engineer a good solution from a signal integrity point of view [1-5]. The modeling of such elements is usually performed with full wave simulation tools. Although this is not an optimum approach for circuit analysis, it provides the insight needed for PCB layout. The extraction of circuit models to use in a SPICE tool avoids time consuming 3D simulations and simplifies the board design. Several methods can be employed to extract equivalent circuits from S-parameters, each of which is characterized by a trade-off between accuracy and complexity. Moreover, the need of an accurate model mainly depends upon the frequency range of interest, in fact, the wider the range is, the more complexity is needed in the equivalent circuit in order to reproduce the initial S-parameter data, which can be considered as the reference to estimate the accuracy of the model itself.

Validation of equivalent circuits extracted from S-parameter data for eye-pattern evaluation

Abstract: S-parameter circuit model extraction is usually characterized by a trade off between accuracy and complexity. Trading one feature for another may or may not affect the goodness of the reconstructed S-parameter data, which are obtained from frequency domain simulations of the models extracted. However, the ultimate test for the validity of these equivalent circuit representations should be left to eye-diagram simulations, which provide useful insights, from an SI point of view, about the degradation of the signal, as it travels through the system. Physics based simplification procedures can be used to tune the models and achieve less complexity, whereas the comparisons of the eye-diagrams may help to quantify the goodness of all these circuits extracted. In fact, the most accurate model is not necessary the best to be used.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

IEEE Transactions on Microwave Theory and Techniques and Antennas and Propagation Announce a Joint Special Issue on Ultra-Wideband (UWB) Technology

Abstract: Before the emergence of ultra-wideband (UWB) radios, widely used wireless communications were based on sinusoidal carriers, and impulse technologies were employed only in specific applications (e.g. radar). In 2002, the Federal Communication Commission (FCC) allowed unlicensed operation between 3.1–10.6 GHz for UWB communication, using a wideband signal format with a low EIRP level (−41.3dBm/MHz). UWB communication systems then emerged as an alternative to narrowband systems and significant effort in this area has been invested at the regulatory, commercial, and research levels.