Development of Prototype Light-weight, Carbon Nanotube Based, Broad Band Electromagnetic Shielded Coaxial Cables

Bibliographic Details
Main Author: Davis, Kevin M.
Language:English
Published: University of Dayton / OhioLINK 2020
Subjects:
EMI
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=dayton1588866235370608
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spelling ndltd-OhioLink-oai-etd.ohiolink.edu-dayton15888662353706082021-08-03T07:14:50Z Development of Prototype Light-weight, Carbon Nanotube Based, Broad Band Electromagnetic Shielded Coaxial Cables Davis, Kevin M. Aerospace Materials Materials Science Electrical Engineering Electromagnetics Engineering Nanoscience Carbon Nanotubes Shielding effectiveness EMI electromagnetic shielding mode stir chamber bulk current injection prototype Modern spacecraft and aircraft are subjected to broad spectrum electromagnetic interference (EMI). A component of these aerospace vehicles that is susceptible to EMI are coaxial cables. Coaxial cables are shielded from EMI by integrating metallic shielding into the cable designs. This shielding can add significant weight to aerospace systems. Weight is a critical design parameter in aerospace systems. To minimize the weight of the shielded cables carbon based shielding material was incorporated into prototype RG-316 coaxial cables. Carbon nanotube (CNT) paper from Nanocomp Technologies and a carbon nanotube material from NanoSperse LLC were evaluated. Mechanical requirements and winding trial results led to the down selection of the Nanocomp material for incorporation into the prototype cables. The prototypes were evaluated for representative EMI environment in a mode stir chamber and bulk current injection to evaluate shielding effectiveness from 100 kHz to 18 GHz. The cables were fatigued using a custom test protocol that applied a tensileload and bending over a radius to approximately 80% of the ultimate tensile strength. This produced damage that resulted in degraded EMI shielding in the cables. The results indicate that the use of multilayered carbon nanotube shielding provided sufficient shielding from 300 MHz to 18 GHz. The weight of single and double wrapped CNT cables were reduced 51% and 47%, respectively, compared to a double layered copper shielded cable. One of the key outcomes was that the CNT shielded cables suffered little or no degradation in shielding effectiveness when mechanically fatigued, which was in stark contrast to metal shielded cables in most cases. The prototypes cables proved to have a technical readiness level (TRL) of 4 having been demonstrated in a representative environment. The prototype cables were successful but had two deficiencies: the EMI shielding effectiveness was insufficient at low frequencies (<300 MHz), and the manufacturing process for the connectors caused problems with the insertion loss and voltage standing wave ratio properties. Specifically, the resistance between the shield and the connector was three orders of magnitude higher than the metallic shield counterparts. The obvious cause of this resistance increase was related to a silver loaded epoxy used to bond the CNT shield to the connector. Increased performance below 300 MHz can be mitigated by further research into incorporating using magnetic lossy particles or more conductive particles into the CNT paper. The latter issue can be mitigated withan improved manufacturing process and further research on connector design. 2020-06-15 English text University of Dayton / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=dayton1588866235370608 http://rave.ohiolink.edu/etdc/view?acc_num=dayton1588866235370608 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic Aerospace Materials
Materials Science
Electrical Engineering
Electromagnetics
Engineering
Nanoscience
Carbon Nanotubes
Shielding effectiveness
EMI
electromagnetic shielding
mode stir chamber
bulk current injection
prototype

spellingShingle Aerospace Materials
Materials Science
Electrical Engineering
Electromagnetics
Engineering
Nanoscience
Carbon Nanotubes
Shielding effectiveness
EMI
electromagnetic shielding
mode stir chamber
bulk current injection
prototype

Davis, Kevin M.
Development of Prototype Light-weight, Carbon Nanotube Based, Broad Band Electromagnetic Shielded Coaxial Cables
author Davis, Kevin M.
author_facet Davis, Kevin M.
author_sort Davis, Kevin M.
title Development of Prototype Light-weight, Carbon Nanotube Based, Broad Band Electromagnetic Shielded Coaxial Cables
title_short Development of Prototype Light-weight, Carbon Nanotube Based, Broad Band Electromagnetic Shielded Coaxial Cables
title_full Development of Prototype Light-weight, Carbon Nanotube Based, Broad Band Electromagnetic Shielded Coaxial Cables
title_fullStr Development of Prototype Light-weight, Carbon Nanotube Based, Broad Band Electromagnetic Shielded Coaxial Cables
title_full_unstemmed Development of Prototype Light-weight, Carbon Nanotube Based, Broad Band Electromagnetic Shielded Coaxial Cables
title_sort development of prototype light-weight, carbon nanotube based, broad band electromagnetic shielded coaxial cables
publisher University of Dayton / OhioLINK
publishDate 2020
url http://rave.ohiolink.edu/etdc/view?acc_num=dayton1588866235370608
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