Electromagnetic shielding performance of carbon foams

The electromagnetic shielding performance of carbon foams is measured using the nested reverberation chamber method in the frequency band 1-4 GHz, which is the frequency range of most cellular phones and microwave ovens. Good values of shielding effectiveness are obtained even with a small thickness of carbon foam. The results are used to assess the correct electrical conductivity values for the investigated materials using a multiple reflection model to compute the material transmission coefficient. The potential applications of such materials are in the lightweight microwave shielding structures that are partially transparent to optical frequencies. (C) 2012 Elsevier Ltd. All rights reserved.