Abstracts - Dipartimento di Elettronica Applicata

Meta 2010 & FEM 2010 – Rome, 13-15 December 2010
Double negative metamaterials based on
ferromagnetic microwire: a numerical study
G. Conte (1) , G. Finocchio (1) , A. Faba (2)(3) , A. Prattella (1) , B. Azzerboni (1) , E.
Cardelli (2)(3)
(1) University of Messina, Department of Matter Physics and Electronic
Engineering - Messina, Italy
(2) University of Perugia, Polo Scientifico e Didattico di Terni,
Terni, Italy
(3) University of Perugia, Department of Industrial Engineering
Perugia, Italy
The double negative (DNG) properties of metamaterials based on array of
ferromagnetic thin wires in the RF spectrum have recently been highlighted
[1,2]. This fact is interesting due the possibility to control the DNG with a
magnetic field applied to the wires (control of the ferromagnetic resonance
frequency).
This work consists of a systematic study of the electric properties of a periodic
array of this kind of media in order to determine how it is influenced the DNG
effect. The negative electric permittivity can be tuned by acting on the
geometric parameters a and r as suggested by Pendry et al [3].
The FTDT method was employed to analyze 1D and 2D array with size of 3x1
and 3x2 in waveguide environment (8÷12 GHz - WR-90 waveguide). The
wires composed by CoSiB have a radius of 2 μm. The performance of the
samples are expressed in terms of scattering parameters S11 and S21 and
normal absorbed power (Pabs=1-|S11| 2 -|S21| 2 ) and calculated for three values of
dc magnetic field (parallel to the wires). For both arrays, the performances are
enhanced when the a (distance between the wires) is increased up to a critical
value (about 5 mm). For larger value the scattering phenomenon is not
negligible. Our computations show the DNG effect is visible only when the
radius of the wire is comparable with the skin length. We also see that the
transmission of the signal in the DNG region roughly decrease in the double
layer case, in the case with a third layer the DNG effects became almost
negligible.
References
[1] J. Carbonell, et al, “Double negative metamaterials based on ferromagnetic microwires,”
Phys. Rev. B 81, 024401, 2010.
[2] H. García-Miquel, J. Carbonell, V. E. Boria and J. Sánchez-Dehesa, “Experimental
evidence of left handed transmission through arrays of ferromagnetic microwires,” Appl-
Phys. Lett. 94, 054103, 2009
[3] J. B. Pendry, J. A. Holden, J. D. Robbins, and J. W. Stewart, “Low frequency plasmons in
thin-wire structures,” J. Phys. Condensed Matter, vol. 10, pp. 4785–4809, 1998
[4] N. Engheta and R. W. Ziolkowski, “Metamaterials. Physics and Engineering
Explorations,” Wiley Inter-Science, IEEE Press, Piscataway, NJ, 2006
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