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.

Decoupling capacitor power ground via layout analysis for multi-layered PCB PDNs

Abstract: A modeling methodology to calculate the decoupling capacitor interconnect inductance in a multi-layer PCB is proposed herein. The methodology is based on the resonant cavity model of parallel planes. The self-inductance and mutual inductance are extracted to understand the via configuration influence on the effectiveness of decoupling capacitors. A special layout of decoupling capacitor is proposed to increase the effectiveness of the decoupling capacitors by taking maximum advantage of the mutual inductance between interconnect vias with two decoupling capacitors placed in a pair, and two pairs of power and ground vias placed in alternating directions as close as possible. The number of decoupling capacitors needed can be reduced dramatically. Three PCB PDN designs are used to present the effectiveness of doublet layout in different design scenarios. Similar analysis is extended to 3-terminal decoupling capacitor layout design. The decoupling capacitor interconnect inductance of the five via layouts for 3-terminal capacitors is analyzed. The number of decoupling capacitors needed for a commercial product using the doublet layout and 3-terminal capacitor layout is compared to the design with an alternating decoupling capacitor layout to reflect the impact of the decap layout design on the PCB PDN performance.

Permeability and permittivity uncertainty effects in modeling absorbing coatings and ferrites on cables

Abstract: Sensitivity analysis of the performance of thin absorbing coatings and ferrite chokes on cables to the variation in dielectric and magnetic properties of materials is carried out. This variation corresponds to possible uncertainty in measuring complex permittivity and permeability of materials. The analysis in this paper is done numerically using the 2D-FEM code. The modeled parameters are input impedance and EMI radiation reduction when applying absorbing materials and ferrite chokes on the cables, represented as monopole antenna rods. The material parameters of absorbing materials and ferrites used in this study were measured using the standard 7-mm coaxial air line. Higher sensitivity of the modeled parameters to the uncertainty of measuring complex permeability of absorbing materials and ferrites, and lower to the uncertainty of measuring complex permittivity, even in the case of high-permittivity absorbing coatings, have been demonstrated.

The advantages of the RTS method in MIMO OTA measurements

Abstract: This paper proposed a radiated two-stage based method for the Multiple Input Multiple Output (MIMO) system evaluations. By using the proposed method, not only the final throughput values, but also the antenna patterns, the antennas' envelope correlation coefficient, the antennas' imbalance and the radiated sensitivity of the MIMO device can be obtained over the air. Moreover, through these parameters, the antenna performance and the radio frequency circuit performance can be investigated individually, which is significant for engineers to find out the imperfections and to improve the design qualities. All in all, this method is valuable for research and development for MIMO devices.

De-embedding techniques for transmission lines: An exploration, review, and proposal

Abstract: In this paper, two transmission line based de-embedding techniques are reviewed for application in 3D IC measurements. In particular, full-wave models of extremely small stripline geometries are investigated. The advantages and drawbacks of each method are discussed in reference to simulation results, and a new hybrid method is proposed.

Revised L –2 L Method for On-Chip De-Embedding

Abstract: An evaluation is presented on the L –2 L de-embedding method for on-chip transmission lines. The method is analyzed using measurement data from two chips. Results are presented in terms of scattering parameters, as is the standard for characterizing system interconnects. The various challenges associated with on-chip modeling and measurements are discussed. Furthermore, a revised version of the L –2 L method is presented, decreasing its sensitivity to measurement noise. All de-embedding results are compared back to “ideal” simulation models for validation or disproof.

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.