The V2O5-MoO3 mixtures offer a whole range of materials where properties can be adjusted by simple modification of experimental parameters, which may be utilized for manufacturing metamaterials with on-demand properties. The V2O5-MoO3 system contains an intermediate phase V9Mo6O40, with a small fraction of V4+ instead of V5+. Consequently, this system should rather be considered as pseudobinary. The V4+ content depends on the oxygen partial pressure in the atmosphere. Thus, by changing the oxygen partial pressure one can tailor the electric properties of the system, and by changing the supercooling, the morphologic structure of crystallized bodies as well. For better understanding of this system differential thermal analysis and thermodynamic modeling was performed. Fibers of eutectic composition between V9Mo6O40 and MoO3 were grown by the micro-pulling-down technique. X-ray diffraction confirmed the existence of the V9Mo6O40 intermediate phase.

We have built and tested electrically small (∼γ/10) resonant patch antennas as proposed in recent literature [1, 2]. The metamaterial array loading the antennas formed a rough cylinder axially enclosed by a patch antenna and a ground plane. The fill ratio, or ratio of the metamaterial array's radius to the patch radius, was less than one. Given a particular negative permeability metamaterial (copper spiral rings printed on circuit board in this case), the fill ratio dictates the lower of two resonant frequencies of the antenna. The higher frequency resonance is characteristic of the patch.

We observed that each of the antennas radiated at two resonant frequencies, as predicted. The lower frequency resonance disappeared when the metamaterial was removed. We built two versions of this antenna, one (Design I) with a lower resonant frequency of 756 MHz and higher resonant frequency of 3.3 GHz, and a second antenna (Design II) with a lower resonant frequency of 385 MHz and higher resonant frequency of 1.8 GHz. Because we were interested in reducing the size of patch antennas, we focused on the lower frequency resonances in this work. The antennas' return loss was measured at -23 dB and -28 dB, the gains were -11 dBi and -13 dBi, and the return loss was less than -10 dB over bandwidths of 4.7% and 1.8% for the lower frequency resonances of Design I and Design II, respectively.

We also predicted the trend of increasing resonant frequency with decreased metamaterial fill ratio. We varied the fill ratio was by changing the patch size while maintaining the same metamaterial array. As predicted, resonant frequency increased with increasing patch size, an opposite trend to what one would expect without the loading metamaterial. Altering the patch size allows simple tuning during the assembly and test process.

The effect of the external magnetic field on the dispersion of the effective permittivity in arrays of parallel CoFe-based amorphous wires is demonstrated by measuring S-parameters in free space in the frequency band of 0.9-17 GHz. The magnetic field is applied along the wires sensitively changing their magnetization and high frequency impedance. Based on the measurements of magneto-impedance in a single wire and transmission/reflection spectra of composites in free space, we show the correlation between magneto-impedance and the field dependence of the effective permittivity.

A novel, first-principle theoretical approach and synergetic computational methods designed to predict electronic and magnetic transport properties of strongly spatially inhomogeneous systems, including small quantum dots and wires (QDs and QWs, respectively), and molecules, have been developed recently. This approach is based on a many-body quantum theoretical formalism - a projection operator method due to Zubarev and Tserkovnikov (ZT) - formulated in terms of the equilibrium, two-time temperature Green functions (or TTGFs). There are several significant advantages of this approach, as compared to traditional non-equilibrium two-time thermodynamic and field-theoretical Green's function (NGF) methods that are currently used to study electronic and magnetic transport properties of strongly spatially inhomogeneous systems. In particular, the TTGFs are directly related to experimentally assessable microscopic charge, spin and microcurrent densities.

In the work reported here the TTGF-based approach has been used to derive a fundamental, yet tractable expression for the space-time Fourier transform of the tensor of quasi-local refraction indices (TRI) from the first principles. The TTGFs necessary to predict TRI can be calculated using quantum statistical mechanical means, modeling and simulations, and experimental data. Applications of the theoretical predictions for TRI open new prospects in materials design. In particular, the derived theoretical expression for TRI can be used to guide experimental synthesis of structured materials and systems with both direction- and position-dependent indices of refraction in desirable frequency ranges.

In this work, scattered electric and magnetic fields of all-dielectric metamaterials were derived using a commercial RF finite-element partial differential equations solver. We present the implementation of rod-type composites consisting of a mixture of two components: the first one, which is called guest, is made of Ba1-xSrxTiO3 (0 ≤ x ≤ 1) and the second one, the host, made of SiO2. Analysis includes both the scattering effect, well described by the MIE theory, and dielectric inhomogeneous structure properties, determined using the MAXWELL-GARNETT approximation.

We perform large-scale finite-difference time-domain (FDTD) simulations with the aid of efficient parallel-computing algorithms for designing optical and acoustic metamaterials, where either electromagnetic or elastic constants in the materials are artificially modulated via nano/micro-structuring.

For optical metamaterials, effects of nanostructure on dielectric properties are taken into account by introducing the Drude-Lorentz model and a hybrid quantum-mechanical/classical FDTD method for optical dispersion of simple metal particles. Using these computational methods, we assess the materials dependence of light-confinement efficiency in the recently proposed novel structure that combines dielectrics and metamaterials periodically.

In the acoustic case, we perform the parallel FDTD simulations of elastic-wave propagations in 2D phononic crystals. The negative refraction of acoustic wave is shown to occur via a negative effective mass appeared in their phonon band-structures. We demonstrate that the focal intensity by the lens effect and its energy-transfer efficiency can be optimized by adapting the filling fraction of the crystal.

Negative refractive index materials tuned at n = -1 are believed to realize perfect lensing of real and evanescent modes. Metamaterials are the natural candidates to realize negative refractive index by the inversion of the effective dielectric permittiviy and magnetic permeability. The effect of the density on the tuning in the proximity of n = -1 is studied in order to find viable solutions to the issue of discretization of the lattice which correspondingly produces steps in the electromagnetic parameters of metamaterials. We study the microwave frequency negative refractive index of a metamaterial as a function of the density of the lattice period. The negative refractive index is realized by means of a waveguide filled with a split ring resonator lattice, exploited below the cut off frequency of the waveguide. We discuss the pass-band behaviour and the collective effects on the negative refractive index.

We have developed miniaturized electromagnetic bandgap (EBG) structures on Si having a stopband that covers the 2.4 GHz band. By combining thin film dielectrics with inductance-enhanced EBG structures, the unit cell size can be reduced to 1 mm × 1 mm or less. Like the EBG structures embedded in conventional printed circuit boards, the stopbands can be designed using the transmission-line theory. The developed EBG structures can be integrated into Si interposers to suppress power noise.

The Boeing Company has developed a unique nanotechnology for antireflective coatings that can perform at near grazing angles (∼80°), in the long wave infrared (LWIR). This technology has been validated through mathematical modeling and the fabrication and testing of small scale components. The coatings were designed to perform best at 10 micron wavelengths, and moderately well over the 8 to 12 micron region. The technology is based upon a circuit analog sheet (capacitive) buried within a dielectric, to produce a reflection that adds out of phase with respect to the face sheet reflection. Since the TE component of the reflection is highest near grazing, the sheet is designed to primarily affect that polarization (low impedance) while leaving the TM wave unaffected (high impedance).

When desired, in order to improve the TM transmission as well as TE, two layers are used at different depths. This dual-layer approach has also been modeled (in closed form), fabricated and tested. Also, explored in this paper, are the impacts of a design that works well azimuthally at grazing angles.

Until recently, the above solution was limited to RF frequencies, but with advances in fabrication it has become possible to fabricate very small nanostructures that operate in LWIR using traditional thin-film vacuum deposition techniques. It is envisioned that eventually such a concept could be used in the visual regime via self assembly.