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.

Formulation and Network Model Reduction for Analysis of the Power Distribution Network in a Production-Level Multilayered Printed Circuit Board

Abstract: A methodology for modeling the power delivery network from the voltage regulator module to the pins of a high pin count integrated circuit on a printed circuit board (PCB) is presented. The proposed model is based on inductance extraction from first principle formulation of a cavity formed by parallel metal planes. Circuit reduction is used to practically realize the model for a production level, complex, multilayer PCBs. The lumped element model is compatible with SPICE-type simulators. The resulting model has a relatively simple circuit topology. The model is corroborated with microprobing measurements up to a few gigahertz. The model can be used for a wide range of geometry variations in a power integrity analysis, including complex power/ground stack up, various numbers of decoupling capacitors with arbitrary locations, numerous IC power pins and IC power/ground return via layouts, as well as hundreds of ground return vias.

An Efficient Hybrid Finite-Element Analysis of Multiple Vias Sharing the Same Anti-Pad in an Arbitrarily Shaped Parallel-Plate Pair

Abstract: A hybrid 3-D and equivalent 2-D finite-element method (FEM) is proposed for signal/power integrity analysis of multiple vias in a shared anti-pad in an arbitrarily shaped parallel-plate pair. The entire domain of the plate pair is decomposed into via-domains and plate domains by virtual interfaces. Complicated fields in via-domains, due to mode conversions from transverse electromagnetic modes in anti-pads or via-holes to parallel-plate modes, are described by a 3-D FEM while in plate domains, only the zeroth-order parallel-plate modes are assumed to exist a little far away from anti-pads. Triangular prism elements are utilized in both via-domains and plate domains. It is proven that the 3-D triangular prism element can be reduced to an equivalent 2-D triangle element by a novel edge numbering process and the boundary conditions along the interfaces of via-domains and plate domains can be automatically satisfied. The accuracy of the hybrid method has been validated by comparison with other numerical methods, and its flexibility, as well as efficiency, are also demonstrated.

Characterization of Via Structures in Multilayer Printed Circuit Boards With an Equivalent Transmission-Line Model

Abstract: Vias are typical discontinuities for high-speed signal transmission in printed circuit boards (PCBs). This paper proposes an equivalent multiconductor transmission-line model for via structures in multilayer PCBs. The proposed model is based on the physic-based circuit model, taking into account distributed effects. Various via structures with arbitrary via number, trace connections, and via stubs can be effectively handled in the equivalent transmission-line model, which is sufficiently accurate and fast to be integrated into circuit simulators for via and link-path analysis. With the proposed model, well-known transmission-line theories can be borrowed for via modeling and characterization for signal integrity in high-speed digital circuits. The proposed model is validated with both full-wave simulations and measurements for multilayer PCBs with different via structures.

Modeling multilayered PCB power-bus designs using an MPIE based circuit extraction technique

Abstract: A circuit extraction tool (CEMPIE) has been developed based on the mixed-potential integral equation (MPIE) using a quasi-static approximation. A power-bus in a multi-layered PCB consisting of a pair of dedicated ground and power planes is studied using this tool. The distributed behavior of a power-bus is represented by a collection of passive circuit elements, which is valid up to several gigahertz. The decoupling performance of a power-bus due to its layer spacing and the dielectric constant is evaluated for simple test geometries. The impact of the relative distance between the noise source and the potential receiver is also studied. Novel structures such as a power island were studied in both thin and thick boards, and the decoupling performance due to the locations and values of the decoupling capacitors were also investigated.

Quantifying EMI: A Methodology for Determining and Quantifying Radiation for Practical Design Guidelines

Abstract: Radiation is a vital mechanism affecting electromagnetic interference (EMI), noise control, and performance optimization in today's electronic designs. Due to tight electromagnetic compatibility standards, it becomes increasingly important to diagnosis the radiation hot spot in the radiation process before the mitigation is applied. In this paper, the characteristic mode analysis has been implemented together with the integral equation based numerical methods to identify the hot spots for EMI radiation. During this process, the current is split into radiating and nonradiating ones. The radiated power from each part of the structure can be quantified using the radiating current. Therefore, the radiation hot spot can be identified. Several numerical examples are applied to benchmark the proposed approach. This paper provides a guideline in discovering radiation related geometrical features, and designing methodologies for real geometries.

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.