This work presents a new chiral composite composed of copper wires braided with Kevlar and nylon to form
conductive coils integrated among structural fiber. To create a fabric, these braids were woven with plain Kevlar
fiber. This yielded a composite with all coils possessing the same handedness, producing a chiral material. The
electromagnetic response of this fabric was first simulated using a finite element full-wave simulation. For the
electromagnetic measurement, the sample was placed between two lens-horn antennas connected to a Vector
Network Analyzer. The frequency response of the sample was scanned between 5.5 and 8GHz. The measured
scattering parameters were then compared to those of the simulated model. The measured parameters agreed well
with the simulation results, showing a considerable chirality within the measured frequency band. The new
composite combines the strength and durability of traditional composites with an electromagnetic design to create a
Previous studies into the possibility of a plasmonic medium of a coiled conductor array in air have shown promise.
This work serves to evaluate the possibility of creating a mechanically-tunable composite filter at low frequencies.
Copper springs were created with varying starting pitches using a coil winder. These springs were then embedded
into a flexible host polymer. The mechanical and electromagnetic properties of each spring design were predicted
and tested. Two horn antennas were used to characterize the overall electromagnetic (EM) properties of the
composite. The pitch of each spring was increased mechanically through application of force to the entire polymermetal
composite at equal intervals, with an EM test completed at each step. Using an Agilent 8510C Vector
Network Analyzer (VNA), the frequency spectrum within the microwave range was scanned. Relative amplitude
and phase measurements were taken at equal frequency and pitch steps. With no polymer surrounding the springs,
plasmon turn-on frequencies were observed to span the microwave bands as the pitch of the springs were increased.
Similar results are expected with the springs embedded in a polymeric matrix. These results suggest a method of
creating a mechanically-tunable composite filter for use at low frequencies.
Materials that exhibit negative refraction demonstrate physical phenomena that may be used for novel applications. This
work serves to evaluate the possibility of hyperbolic focusing due to an indefinite anisotropic permittivity tensor. Two
single-loop antennas were used to approximately achieve a transverse magnetic (TM) point source and detector. Using
an Agilent 8510C Vector Network Analyzer (VNA), the frequency spectrum was scanned between 7 and 9 GHz.
Relative gain or loss measurements were taken at equal spatial steps around the center of the sample. A scanning robot
allowed for the automatic scanning of the space behind the sample in the x, y, and z directions, to establish the focusing
patterns, and to compare the signal amplitudes in the presence and absence of the sample. The robot was controlled using
LabVIEW, which also collected the data from the VNA and passed it to Matlab for processing. A soft focusing spot was
observed when the antennas were placed in a symmetric configuration with respect to the sample. These results suggest a
method of focusing electromagnetic waves using negative refraction in indefinite materials.