Measured average absorption cross-sections of printed circuit boards from 2 to 20 GHz

TY - JOUR

T1 - Measured average absorption cross-sections of printed circuit boards from 2 to 20 GHz

AU - Flintoft, Ian David

AU - Parker, Sarah

AU - Bale, Simon Jonathan

AU - Marvin, Andy

AU - Dawson, John Frederick

AU - Robinson, Martin Paul

N1 - © 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. This is an author produced version of a paper published in IEEE Transactions on Electromagnetic Compatibility. Uploaded in accordance with the publisher's self-archiving policy.

PY - 2016/4

Y1 - 2016/4

N2 - The contents of an equipment enclosure, particularly printed circuit boards (PCBs), affect the enclosure’s shielding performance. At high frequencies this absorption can be quantified using the angle of arrival and polarization averaged absorption cross-section (ACS). However, there is no available data on the high-frequency absorption characteristics of modern PCBs. In this study we apply a reverberation chamber to the determination of the average ACS of a large number of printed circuit boards taken from contemporary information and communication technology (ICT) equipment to provide a unique and comprehensive data-set. The ACS was found to range from 4×10-4 –10-2 m2 from 2-20 GHz and different classes of PCB could be identified according to their surface characteristics. The "shadowing effect" of densely packed PCBs was also quantified for a subset of the PCBs. It was found that the ACS of a PCB in the stack was reduced by 20% - 40% compared to its value when isolated. By way of a review of the general power balance analysis of an electrically large populated equipment enclosure in an external environment we show how the acquired data will be useful for future qualification methodologies for ICT enclosures and PCBs.

AB - The contents of an equipment enclosure, particularly printed circuit boards (PCBs), affect the enclosure’s shielding performance. At high frequencies this absorption can be quantified using the angle of arrival and polarization averaged absorption cross-section (ACS). However, there is no available data on the high-frequency absorption characteristics of modern PCBs. In this study we apply a reverberation chamber to the determination of the average ACS of a large number of printed circuit boards taken from contemporary information and communication technology (ICT) equipment to provide a unique and comprehensive data-set. The ACS was found to range from 4×10-4 –10-2 m2 from 2-20 GHz and different classes of PCB could be identified according to their surface characteristics. The "shadowing effect" of densely packed PCBs was also quantified for a subset of the PCBs. It was found that the ACS of a PCB in the stack was reduced by 20% - 40% compared to its value when isolated. By way of a review of the general power balance analysis of an electrically large populated equipment enclosure in an external environment we show how the acquired data will be useful for future qualification methodologies for ICT enclosures and PCBs.

KW - shielding, printed circuit board, absorption cross-section, reverberation chamber, immunity, emissions, power balance

U2 - 10.1109/TEMC.2016.2515658

DO - 10.1109/TEMC.2016.2515658

M3 - Article

SN - 0018-9375

VL - 58

SP - 553

EP - 560

JO - IEEE Transactions on Electromagnetic Compatibility

JF - IEEE Transactions on Electromagnetic Compatibility

IS - 2

ER -