scholarly journals A Dual-Perforation Electromagnetic Bandgap Structure for Parallel-Plate Noise Suppression in Thin and Low-Cost Printed Circuit Boards

Electronics ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 719
Author(s):  
Myunghoi Kim
Keyword(s):  
Cell Size ◽  
Parallel Plate ◽  
Printed Circuit Boards ◽  
Noise Suppression ◽  
Low Cost ◽  
Unit Cell ◽  
Circuit Boards ◽  
Electromagnetic Bandgap ◽  
Unit Cell Size ◽  
Full Wave

In this study, we propose and analyze a dual-perforation (DP) technique to improve an electromagnetic bandgap (EBG) structure in thin and low-cost printed circuit boards (PCBs). The proposed DP–EBG structure includes a power plane with a square aperture and a patch with an L-shape slot that overcomes efficiently the problems resulting from the low-inductance and the characteristic impedance of the EBG structure developed for parallel-plate noise suppression in thin PCBs. The effects of the proposed dual-perforation technique on the stopband characteristics and unit cell size are analyzed using an analytical dispersion method and full-wave simulations. The closed-form expressions for the main design parameters of the proposed DP–EBG structure are extracted as a design guide. It is verified based on full-wave simulations and measurements that the DP technique is a cost-effective method that can be used to achieve a size reduction and a stopband extension of the EBG structure in thin PCBs. For the same unit cell size and low cut-off frequency, the DP–EBG structure increases the stopband bandwidth by up to 473% compared to an inductance-enhanced EBG structure. In addition, the unit cell size is substantially reduced by up to 94.2% compared to the metallo–dielectric EBG structure. The proposed DP–EBG technique achieves the wideband suppression of parallel plate noise and miniaturization of the EBG structure in thin and low-cost PCBs.

Miniaturization of Electromagnetic Bandgap Structures with Thin Film Dielectrics for Si Interposer Applications

2009 ◽  
Vol 1223 ◽  
Author(s):  
Koichi Takemura ◽  
Noriaki Ando ◽  
Hiroshi Toyao ◽  
Takashi Manako ◽  
Tsuneo Tsukagoshi
Keyword(s):  
Thin Film ◽  
Printed Circuit Boards ◽  
Circuit Boards ◽  
Electromagnetic Bandgap ◽  
Transmission Line Theory ◽  
Printed Circuit ◽  
Unit Cell Size ◽  
Line Theory ◽  
Power Noise ◽  
Thin Film Dielectrics

ABSTRACTWe have developed miniaturized electromagnetic bandgap (EBG) structures on Si having a stopband that covers the 2.4 GHz band. By combining thin film dielectrics with inductance-enhanced EBG structures, the unit cell size can be reduced to 1 mm × 1 mm or less. Like the EBG structures embedded in conventional printed circuit boards, the stopbands can be designed using the transmission-line theory. The developed EBG structures can be integrated into Si interposers to suppress power noise.

scholarly journals On the Suppression Band and Bandgap of Planar Electromagnetic Bandgap Structures

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Baharak Mohajer-Iravani ◽  
Omar M. Ramahi
Keyword(s):  
Printed Circuit Boards ◽  
Signal Integrity ◽  
Three Dimensional ◽  
Design Guidelines ◽  
Switching Noise ◽  
Circuit Boards ◽  
Electromagnetic Bandgap ◽  
Full Wave ◽  
Viable Solution ◽  
Simulation Based

Electromagnetic bandgap structures are considered a viable solution for the problem of switching noise in printed circuit boards and packages. Less attention, however, has been given to whether or not the introduction of EBGs affects the EMI potential of the circuit to couple unwanted energy to neighboring layers or interconnects. In this paper, we show that the bandgap of EBG structures, as generated using the Brillouin diagram, does not necessarily correspond to the suppression bandwidth typically generated usingS-parameters. We show that the reactive near fields radiating from openings within the EBG layers can be substantial and are present in the entire frequency band including propagating and nonpropagating mode regions. These fields decay fast with distance; however, they can couple significant energy to adjacent layers and to signal lines. The findings are validated using full-wave three-dimensional numerical simulation. Based on this work, design guidelines for EBG structures can be drawn to insure not only suppression of switching noise but also minimization of EMI and insuring signal integrity.

scholarly journals Unit-Cell-Based Domain Decomposition Method for Efficient Simulation of a Truncated Electromagnetic Bandgap Structure in High-Speed PCBs

Electronics ◽  
2018 ◽  
Vol 7 (9) ◽  
pp. 201 ◽  
Author(s):  
Myunghoi Kim
Keyword(s):  
Domain Decomposition ◽  
Decomposition Method ◽  
High Speed ◽  
Printed Circuit Boards ◽  
Domain Decomposition Method ◽  
Unit Cell ◽  
Electromagnetic Bandgap ◽  
Wave Simulation ◽  
Full Wave ◽  
Impedance Parameter

In this paper, we present a unit-cell-based domain decomposition method (UC-DDM) for rapid and accurate simulation of predicting the parallel plate noise (PPN) suppression of a truncated electromagnetic bandgap (EBG) structure in high-speed printed circuit boards (PCBs). The proposed UC-DDM divides the analysis domain of the truncated EBG structure into UCs as sub-domains. Solving a sub-domain is based on a novel UC model, yielding an analytical expression for the impedance parameter (Z-parameter) of the UC. The novel UC model is derived using a spatial decomposition technique, which results in the modal decomposition of quasi-transverse electromagnetic (TEM) and transverse magnetic (TM) modes. In addition, we analytically derive a impedance-parameter recombination method (ZRM) to obtain the analytical solution of a finite EBG array from the sub-domain results. The proposed UC-DDM is verified through comparison with full-wave simulation results for various EBG arrays. Comparison between the UC-DDM and a full-wave simulation of a truncated EBG structure reveals that a substantial improvement in computation time with high accuracy is achieved. It is demonstrated that the simulation time of the proposed method is only 0.1% of that of a full-wave simulation without accuracy degradation.

scholarly journals Fabrication and Compressive Behavior of a Micro-Lattice Composite by High Resolution DLP Stereolithography

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 785
Author(s):  
Chow Shing Shin ◽  
Yu Chia Chang
Keyword(s):  
High Resolution ◽  
Lattice Structure ◽  
Low Cost ◽  
Hierarchical Structures ◽  
Dip Coating ◽  
Unit Cell ◽  
Digital Light Processing ◽  
Unit Cell Size ◽  
Wide Range ◽  
And Performance

Lattice structures are superior to stochastic foams in mechanical properties and are finding increasing applications. Their properties can be tailored in a wide range through adjusting the design and dimensions of the unit cell, changing the constituent materials as well as forming into hierarchical structures. In order to achieve more levels of hierarchy, the dimensions of the fundamental lattice have to be small enough. Although lattice size of several microns can be fabricated using the two-photon polymerization technique, sophisticated and costly equipment is required. To balance cost and performance, a low-cost high resolution micro-stereolithographic system has been developed in this work based on a commercial digital light processing (DLP) projector. Unit cell lengths as small as 100 μm have been successfully fabricated. Decreasing the unit cell size from 150 to 100 μm increased the compressive stiffness by 26%. Different pretreatments to facilitate the electroless plating of nickel on the lattice structure have been attempted. A pretreatment of dip coating in a graphene suspension is the most successful and increased the strength and stiffness by 5.3 and 3.6 times, respectively. Even a very light and incomplete nickel plating in the interior has increase the structural stiffness and strength by more than twofold.

Determination of Optimal Unit-Cell Size of Homogeneous Conformal Unit-Cell Lattice Structure Using Solid Shape Matching

2016 ◽  
Author(s):  
Mahmoud A. Alzahrani ◽  
Seung-Kyum Choi
Keyword(s):  
Cell Size ◽  
Solid Body ◽  
Strain Energy ◽  
Lattice Structure ◽  
Weight Ratio ◽  
Unit Cell ◽  
Optimal Size ◽  
Lattice Structures ◽  
Unit Cell Size ◽  
Unit Cells

With rapid developments and advances in additive manufacturing technology, lattice structures have gained considerable attention. Lattice structures are capable of providing parts with a high strength to weight ratio. Most work done to reduce computational complexity is concerned with determining the optimal size of each strut within the lattice unit-cells but not with the size of the unit-cell itself. The objective of this paper is to develop a method to determine the optimal unit-cell size for homogenous periodic and conformal lattice structures based on the strain energy of a given structure. The method utilizes solid body finite element analysis (FEA) of a solid counter-part with a similar shape as the desired lattice structure. The displacement vector of the lattice structure is then matched to the solid body FEA displacement results to predict the structure’s strain energy. This process significantly reduces the computational costs of determining the optimal size of the unit cell since it eliminates FEA on the actual lattice structure. Furthermore, the method can provide the measurement of relative performances from different types of unit-cells. The developed examples clearly demonstrate how we can determine the optimal size of the unit-cell based on the strain energy. Moreover, the computational cost efficacy is also clearly demonstrated through comparison with the FEA and the proposed method.

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