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.

Parametric study on the effect of asymmetry in multi-channel differential signaling

Abstract: The effects of geometric asymmetry on the electrical performance of multi-channel differential signaling in printed circuit boards are investigated in this paper. The asymmetry, which is the origin of noise coupled through mode conversion, is difficult to control in real channel structures, where a large number of vias and traces are populated. Supported by an efficient parametric simulation tool, this paper presents the effects of the asymmetry on mode conversion and differential mode crosstalk in real multi-channel structures. This extensive parametric study was used to define design guidelines to suppress this noise coupling by adding ground vias in strategic locations.

DC power bus modeling using a circuit extraction approach based on a mixed-potential integral equation formulation and an iterative equation solver

Abstract: DC power bus modeling in multilayer printed circuit boards (PCB) or multichip module (MCM) substrates is a critical issue in high-speed digital circuit design. This paper presents a quick and simple approach to perform circuit simulations for an equivalent circuit extracted from a first principles formulation for DC power bus structures. Comparisons between the modeling and measurements demonstrate the application of this approach in DC power bus designs.

De-embedding techniques for transmission lines: An application to measurements of on-chip coplanar traces

Abstract: In this paper, the de-embedding study presented in the work of Erickson et al. (2013) is extended from the simulation environment to the measurement environment; the three presented de-embedding methods are applied to measurements of on-chip coplanar traces for two different test ICs. Additionally, the Hybrid technique presented in work of Erickson et al. is reformulated so that only two measurement standards are required, as opposed to three. The results of de-embedding the measurement data are discussed, as well as challenges with making the measurements.

PCB Edge Shielding Effectiveness Evaluation and Design Guidelines

Abstract: Edge plating and via stitching connecting ground planes are two common edge treatments to suppress electromagnetic interference (EMI) from multilayer printed circuit boards (PCB). One critical parameter for stitching via is the spacing between vias. At higher frequencies, it is desirable to plate the edges of PCB, and a gap is required in the plating to accommodate the break-off tabs. In this paper, the shielding performance of these two scenarios are studied in both simulation and measurement. By sweeping the parameters of via pitch size and the length of each plated edge, the near-field shielding effectiveness (SE) of these different cases are compared. In general, the edge plating cases have much better shielding performance than the stitching via ones. Since edge plating implements the shielding on PCB walls, it leaves no interference with signals and moreover saves space for dropping GND stitching vias, with a trade-off of 5% more cost. Design guidelines for PCB edge treatments are provided in the end of the paper.

A planar low-profile meander antenna design for wireless terminal achieving low self-interference

Abstract: In this paper, a new internal antenna used for wireless terminal is proposed. The current of this antenna is mostly distributed on the antenna radiator itself, rather than on the main board of the wireless device. As a result, the chance of having self-interference issues, which usually result in receiver desensitization in wireless radios, can be significantly reduced. The antenna has better radiation performance in the vertical polarization with a low profile, and the average gain of this antenna is good as well. Both simulation and measurement results demonstrate the proposed design.

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.