147 research outputs found
Q-based design equations for resonant metamaterials and experimental validation
Practical design parameters of resonant metamaterials, such as loss tangent,
are derived in terms of the quality factor of the resonant effective medium
permeability or permittivity. Through electromagnetic simulations of loop-based
resonant particles, it is also shown that the of the effective medium
response is essentially equal to the of an individual resonant particle.
Thus, by measuring the of a single fabricated metamaterial particle, the
effective permeability or permittivity of a metamaterial can be calculated
simply and accurately without requiring complex simulations, fabrication, or
measurements. Experimental validation shows that the complex permeability
analytically estimated from the measured of a single fabricated
self-resonant loop agrees with the complex permeability extracted from
parameter measurements of a metamaterial slab to better than 20%. This
equivalence reduces the design of a metamaterial to meet a given loss
constraint to the simpler problem of the design of a resonant particle to meet
a specific constraint. This analysis also yields simple analytical
expressions for estimating the loss tangent of a planar loop magnetic
metamaterial due to ohmic losses. It is shown that
is a strong lower bound for magnetic loss tangents for frequencies not too far
from 1 GHz. The ohmic loss of the metamaterial varies inversely with the
electrical size of the metamaterial particle, indicating that there is a loss
penalty for reducing the particle size at a fixed frequency
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