Design and Evaluation of Radiated Emission Metamaterial Absorbers

In this paper, mitigation of unwanted radiated electromagnetic emissions from a high-speed system enclosure using metamaterial-based absorbers is investigated. First, the performance of an earlier introduced frequency selective metamaterial absorber is thoroughly evaluated via full-wave simulations and compared with that of a commercial thin microwave absorber. An experimental in-lab test set-up is developed to validate simulation results confirming that a stronger mitigation of radiated emissions is delivered by the proposed absorber. The measured radiated emission patterns closely follow simulated results and confirm better than 5 dB reduction in emissions when the proposed absorber is included in the enclosure box. Simulations with simultaneous excitation of multiple radiation sources inside the box prove the effectiveness of the developed absorber in realistic operational conditions that could include array effects for unintentional radiation sources. A second absorber design is introduced in this paper with improved thermal conductivity while providing emission reduction better than 4.6 dB.