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.

Far-End Crosstalk Mitigation for Microstrip Lines in High-Speed PCBs

Abstract: With improvement in the speed and frequency of electronic circuits, far-end crosstalk (FEXT) problem in printed-circuit board (PCB) neighboring routes becomes one of most critical factors affecting signal quality. In this paper, the FEXT can be mitigated significantly by inserting rectangular-shape resonators (RSR) structures in the coupled microstrip transmission lines where defected microstrip structures (DMS) are etched on the lines. The frequency domain simulation of HFSS shows that the S 41 of this proposed structure is decreased more than 16dB around 3.2GHz, compared with the traditional signal routing. The time domain simulation of ADS shows that the peak of FEXT voltage of this structure is improved to 89% compared to the traditional signal routing. It has been successfully demonstrated by simulation and comparison with all previous techniques that, this novel technique gives the best optimum low values for the peak voltage of FEXT. Thus, there is a great potential in DDR5, where the requirement of the high density wiring design is even severe.

On-Chip Voltage Regulator Module (VRM) Effect on Power/Ground Noise and Jitter At High-Speed Output Buffer

Abstract: On-chip voltage regulator module (VRM) for the reduction of power/ground noise on power distribution network (PDN) and jitter minimization at high-speed output buffer is introduced. The basic topology and optimized operation for on-chip VRM is analyzed. A PDN with on-chip VRM shows reduced power/ground noise through removing additional effects coming from package/PCB PDN. Also, when on-chip VRM is implemented on PDN of high-speed output buffers, jitter at output signal is lower. Improvements on PDN and jitter through on-chip VRM are shown and validated with SPICE simulation with 110nm CMOS technology library.

A Planar Low-Profile Meander Antenna (PLMA) Design for Wireless Terminal Achieving Between Intrasystem EMC and Isolation in Multiantenna Systems

Abstract: In this paper, a meander line 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 intrasystem electromagnetic compatibility issues, which usually result in receiver desensitization in wireless radios, can be significantly reduced. The antenna has good radiation performance in the vertical polarization with a low physical profile, compared to the existing antenna designs for typical wireless terminals. The antenna has efficiency similar to the monopole antenna with much less reference/ground plane dependence, which is important for high sensitivity radio design. Further, the mutual coupling (i.e., isolation) between the two such antennas is studied and the envelope correlation coefficient between the two such antennas when they are placed in one system is found to be low, which is important for better throughput for a multiple input and multiple output system. Both simulation and measurement results demonstrate the proposed design.

Parallel Plate Impedance and Equivalent Inductance Extraction Considering Proximity Effect by a Modal Approach

Abstract: A modal approach for parallel plate impedance and equivalent inductance extraction for power integrity analysis including ball grid arrays (BGAs) between two parallel plates is presented. Since the BGAs are placed close to each other, the current flowing through each ball is not uniformly distributed due to the proximity effect. In this paper, a modal-based cavity method is proposed to count for this proximity effect. Analytical solutions for both the parallel plate impedance and the equivalent inductances associated with the BGAs are derived from the modal-based cavity method. The proposed method is validated by finite element method simulations and the application of the proposed method for power distribution network design is demonstrated.

Radiation Physics and Design Guidelines of High-Speed Connectors

Abstract: High-speed connectors contribute to system-level electromagnetic interference (EMI). Radiation from antenna-mode current and transmission-line (TL)-mode current is briefly reviewed with a backplane connector and an optical cage connector. The radiation from the high-speed connector with TL-mode current is analyzed in detail. The possible radiation mechanisms are analyzed respectively through Green's function method, steepest descent method, and electromagnetic compatibility studio method of moment. Design guidelines of high-speed connectors for EMI mitigation are proposed based on the analysis of radiation physics.

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.