F. de Paulis

A Simple and Efficient Design Procedure for Planar Electromagnetic Bandgap Structures on Printed Circuit Boards

In this paper, a simple synthesis procedure to design planar electromagnetic bandgap (EBG) structures is proposed. It is based on the consideration of the excess of inductance of a patterned plane with respect to a solid one. The planar EBG structure is sized from the bandgap starting and ending frequencies, and few others specifications employing a closed form formulation. The proposed method is also suitable for the design of embedded planar EBG. The procedure is validated by using measured and numerically computed results.

Compact Configuration for Common Mode Filter Design based on Planar Electromagnetic Bandgap Structures

A planar electromagnetic bandgap configuration of a compact common mode filter that is laid out on printed circuit board is studied. This filter is used to mitigate the common mode noise traveling on high-speed differential signal traces. These differential signal lines may be connected to I/O connectors and cables and small amounts of common mode noise can result in significant electromagnetic emissions. The filter is obtained by a very simple planar geometry based on the electromagnetic bandgap structures. A cavity made by a rectangular/square patch (together with a solid plane underneath) has a well known and predictable resonant behavior; the coupling between the differential pair routed on top of the patterned plane and the patch cavity, occurring when the traces cross the gap between adjacent patches, is used to reduce the energy associated with the propagation of the common mode noise. The properties of this filter are studied taking into account the layout of a real differential microstrip and the number of gap crossings. A compact configuration is proposed. Time domain simulations validate the suggested layout approach.

IR-DROP Analysis and Thermal Assessment of Planar Electromagnetic Bandgap Structures for Power Integrity Applications

This paper investigates the relationship among the high-frequency performances of a planar electromagnetic bandgap structure for power integrity applications and its static (dc) behavior. The IR-Drop and the thermal performances are accurately investigated through 3-D simulations. Measurements of the high-frequency electromagnetic properties and of the temperature variation are also performed for validating the models employed in the analysis.

Common mode filtering performances of planar EBG structures

This paper approaches the filtering behavior of Electromagnetic Bandgap (EBG) structures. The transfer function, in terms of S-parameters, of a single ended and a differential microstrip line referenced to an EBG plane are considered: the notches (causing signal attenuation) and flat regions (causing signal propagation) are related to the geometry and characteristics of the EBG structure and can be designed to filter out unwanted harmonic components of the signal. A different EBG-like structure is proposed and its performances analyzed.

Signal Integrity Analysis of Single-Ended and Differential Striplines in Presence of EBG Planar Structures

The present contribution performs a systematic analysis of the impact of planar (or 2-D) EBG structures on the signal transmission performances of single ended and differential striplines that have the patterned plane of the EBG structure as a current reference.

Design of a Common Mode Filter by Using Planar Electromagnetic Bandgap Structures

In this paper, an embedded electromagnetic bandgap structure is proposed for harmonic filtering of differential signals undesired common mode components. Rather than use lumped circuit components and likely causing some degradation to the intended high speed differential signal, the embedded planar common mode filter causes no degradation to the intended signal, and enhances the signal integrity and electromagnetic compatibility performance of the system. Single ended and differential traces are considered and the impact of the common mode filtering is measured in terms of mixed mode scattering parameters and eye diagram metrics. The systematic procedure to design such a structure is outlined, and its design robustness is also verified.

Bandwidth Enhancement Based on Optimized Via Location for Multiple Vias EBG Power/Ground Planes

The ground surface perturbation lattice (GSPL) structure is investigated to suppress power noise in the power distribution network of mixed signal circuits. In order to enhance the bandwidth of the noise suppression, the GSPL structure is implemented by using multiple vias in the mushroom-like electromagnetic bandgap structure. Under the concept of multiple vias, the lower and upper bound cutoff frequencies of the bandgap are influenced by the position of the vias. An optimum position for the vias is found to achieve maximum stopband bandwidth. In this paper, the stopband mechanism of GSPL structure is investigated and the corresponding equivalent circuit model is proposed to quickly predict the lower and upper bound cutoff frequencies. Suitable test boards are fabricated and measured to demonstrate the accuracy of the design concept. The result shows that there is a good consistency between simulated, modeled, and measured results.

From Maxwell Garnett to Debye Model for Electromagnetic Simulation of Composite Dielectrics—Part II: Random Cylindrical Inclusions

A semianalytical approach to obtain an equivalent Debye frequency dependence of effective permittivity for biphasic materials with random spherical inclusions from the well-known Maxwell Garnett (MG) mixing rule is proposed. Different combinations of frequency characteristics of mixture phases (host and inclusions) are considered: when at least one of the phases is frequency independent; lossy (with dc conductivity); or with a known single-term Debye frequency dependence. The equivalent Debye models approximate very well the frequency characteristics obtained directly from MG mixing rule. In some cases, there is an exact match between the two models, and a good approximation is achieved in the other cases and is quantified by the feature selective validation technique. The parameters of the derived equivalent Debye model can be employed in full-wave time-domain numerical electromagnetic codes and tools. This will allow for efficient wideband modeling of complex electromagnetic structures containing composite materials with effective dielectric parameters obtained through MG mixing rule.

Fundamental mechanisms of coupling between planar electromagnetic bandgap structures and interconnects in high-speed digital circuits. Part I - microstrip lines

The paper studies the signal integrity performances of a microstripline routed over a planar EBG structure. The fundamental mechanisms of the coupling between the signal transmitted along the trace and the resonant properties of the same structure are investigated.

Diagnosis of Multiple Wiring Faults Using Time-Domain Reflectometry and Teaching–Learning-Based Optimization

Abstract Time-domain reflectometry has proven to be one of the best methods for wiring network diagnosis, and it can easily be applied to the detection and localization of defects, while only requiring one access point to the wiring network. In this article, a novel approach combining the time-domain reflectometry response extracted from vector network analyzer measurements and the teaching–learning-based optimization technique is developed and applied to the diagnosis of wiring networks. The proposed approach consists of two steps. In the first step, propagation along the cables is modeled using the forward model. In the second step, teaching–learning-based optimization is used to solve the inverse problem to deduce physical information about the defects in the wiring network. The proposed approach has been successfully tested on several cases and for different configurations. Comparisons of the proposed time-domain reflectometry/teaching–learning-based optimization approach results with measurements reveal that this approach has a high potential and is very effective for wiring network diagnosis.