Multifunctional composites with negative refractive index

Tuesday, October 3, 2006 - 11:00am - 11:50am
EE/CS 3-180
Sia Nemat-Nasser (University of California, San Diego)
We outline recent achievements in creating structural composite
materials with controlled electromagnetic properties, as an integral
part of a multifunctional material system. The electromagnetic
response is tailored by incorporating within the material small
amounts of suitably configured, periodically distributed, electric
conductors to produce distributed electric inductance and
capacitance. The small-scale response of the conductors can be
homogenized to give overall macroscopic EM material properties at
wavelengths that are orders of magnitude larger than the dimensions
of the periodicity of the structure. Periodic arrays of inductive
elements such as thin straight wires, loop-wires, coils, and other
conductive thin metallic structures can modify the effective electric
permittivity and the effective magnetic permeability of a composite
and make it negative. I will discuss the process of design, analysis,
manufacturing, and measurement of such composites. In particular, I
will review the UCSD's work on the design, production, and
experimental characterization of a 2.7 mm thick composite panels
having negative refractive index between 8.4 and 9.2 GHz. I will
also examine our work on a flat lens having a gradient variation of
negative index of refraction that can focus in the 10GHz range,
showing excellent agreement with full-wave simulations.
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