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322 Biomimetics: Biologically Inspired Technologies

E
H
k

Figure 12.11 Original SRR design with wave vector k, electric E, and magnetic H fields indicated for effective
negative permeability.

Figure 12.12, and called the construction folded-doubled-resonator (FDR). Measurements, using
a focused beam EM characterization system, Figure 12.13, revealed that indeed the composite
had a negative m over a frequency range of about 8.5 to 9.5 GHz. Following this, a new design was
conceived, numerically simulated, and constructed that had a more pronounced negative m.This
construction is shown in Figure 12.14, and the measured results are given in Figure 12.15. As is
discussed in the next section, combining the negative « and m, it is possible to construct a composite
panel with negative index of refraction.

Figure 12.12 FDR design produces the required resonance with a thickness that lends itself to inclusion into an
actual composite panel of reasonable thickness.

Sample

Port 1 Port 2

Figure 12.13 (See color insert following page 302) (Left) Schematic and (right) photo of Focused Beam
system for EM characterization from 5 to 40 GHz at UCSD’s CEAM.