Experimental verification of metamaterial based subwavelength microwave absorbers
Author
Alici, K. B.
Bilotti, F.
Vegni, L.
Özbay, Ekmel
Date
2010-10-29Source Title
Journal of Applied Physics
Print ISSN
0021-8979
Publisher
American Institute of Physics
Volume
108
Issue
8
Pages
083113-1 - 083113-6
Language
English
Type
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Abstract
We designed, implemented, and experimentally characterized electrically thin microwave absorbers by using the metamaterial concept. The absorbers consist of (i) a metal back plate and an artificial magnetic material layer; (ii) metamaterial back plate and a resistive sheet layer. We investigated absorber performance in terms of absorbance, fractional bandwidth, and electrical thickness, all of which depend on the dimensions of the metamaterial unit cell and the distance between the back plate and metamaterial layer. As a proof of concept, we demonstrated a λ/4.7 thick absorber of type I, with a 99.8% absorption peak along with a 8% fractional bandwidth. We have shown that as the electrical size of the metamaterial unit cell decreases, the absorber electrical thickness can further be reduced. We investigated this concept by using two different magnetic metamaterial inclusions: the split-ring resonator (SRR) and multiple SSR (MSRR). We have also demonstrated experimentally a λ/4.7 and a λ/4.2 thick absorbers of type II, based on SRR and MSRR magnetic metamaterial back plates, respectively. The absorption peak of the SRR layout is 97.4%, while for the MSRR one the absorption peak is 98.4%. The 10 dB bandwidths were 9.9% and 9.6% for the SRR and MSRR cases, respectively.
Keywords
AbsorbancesAbsorption peaks
Artificial magnetic materials
Electrical thickness
Experimental verification
Fractional bandwidths
Magnetic metamaterials
Microwave absorbers
Proof of concept
Resistive sheets
Splitring resonators
Sub-wavelength
Type II
Unit cells
Bandwidth
Magnetic materials
Metamaterials
Plate metal
Ring gages
Sheet metal
Absorption