Accurate and Efficient Analysis of Planar Electromagnetic Band-Gap Structures for Power Bus Noise Mitigation in the GHZ Band

Abstract

Abstract-Noise reduction in PCB is a major concern in the present digital electronic systems with data rate beyond 10 Gbps. The noise, due to simultaneous switching noise, radiation from signal vias crossing the planes, etc. can propagate within parallel plane cavity at its resonant frequencies, thus allowing coupling between integrated circuits (ICs) far from each other. Electromagnetic band-gap (EBG) structures are largely employed as noise reduction technique. This paper presents a quick and efficient analytical approach for evaluating the EBG noise reduction performances in terms of band-gap limits. The study is based on the physics behavior of the planar EBG structures, focusing on its resonant properties. The resonant modes of the EBG cavity are affected by the additional inductance of the patterned plane respect to the case of the ideal solid plane cavity. The formulas provided, based on the quantification of such inductance, can be easily implemented and employed for a quick layout design of power planes in multilayer PCBs, as shown in a practical example of a partial EBG plane.

Impact of planar electromagnetic band-gap structures on IR-DROP and signal integrity in high speed printed circuit boards

“…The planar EBG technology, instead, can be used to overcome this problem, as an effective solution for noise mitigation in the GHz range. The planar EBG, based on a sequence of square patches connected by narrow bridges, can be designed according to the quick and efficient procedure described in [7]. The idea is to create a sort of EBG fence between the three areas, avoiding to place the EBG on the entire PCB surface of the second layer; this reduces signal integrity problems for microstrips interconnects referenced on the EBG.…”

“…Therefore the planar EBG structures can be effective to mitigate the noise propagation within power/ground planes [3]- [5]. The EBG can be efficiently designed following the quick analytical procedure shown in [6]- [7]. The idea is to create three areas divided by narrow EBG sections to reduce the noise propagation among the three ICs required by the electrical design.…”

“…The EBG geometry is typically designed either unconnected to the surrounding metallic area, or it covers the entire PCB surface [8]. A modified version firstly proposed in [7], is employed herein placing the EBG on small portion of the power layer to ensure the advantages of the mostly solid reference for high speed traces; the EBGs are also connected to the three solid plane portions by means of small bridges. This realize the DC connection on the entire plane, and thus allow to utilize a single DC/DC converter to supply the three ICs that require the same voltage level.…”

“…The limited space of Area 4 does not allow to achieve a band-gap able to cover also the first harmonic of the signal spectrum. A possible geometry that can fit the available Area 4 is synthesized employing the procedure in [6]- [7]. The proposed EBG geometry and modified layout is analyzed firstly in terms on reduction of noise propagation within the power plane cavity among the three IC locations.…”

Compact Ebg Structure for Alleviating Mutual Coupling Between Patch Antenna Array Elements

“…The recent advancement in the research on metamaterials and electromagnetic band gap materials is continuously stimulating new antenna applications and new technological solutions [1][2][3][4][5]. Microstrip antennas are very attractive from the perspective of designing compact and cost effective wireless communication systems.…”