We propose an improved method to retrieve the effective constitutive parameters (permittivity and permeability) of a slab of metamaterial from the measurement of S parameters. Improvements over existing methods include the determination of the first boundary and the thickness of the effective slab, the selection of the correct sign of effective impedance, and a mathematical method to choose the...

We present a ground penetrating radar (GPR) system, which uses an antenna array for in situ measurements of the thickness and dielectric permittivity of an asphalt pavement layer. We calibrated the antenna array by considering the antenna phase center and the antenna offset. The results of the laboratory measurements demonstrate that the proposed calibration method can greatly improve the accur...

In this work, an approach for the reconstruction of both geometrical and dielectric properties of multiple defects inside a known host medium is analyzed. In particular, the GAbased integrated strategy is applied starting from the knowledge of the scattered field in an external measurement domain in order to determine positions, sizes and dielectric permittivities of the defects, as well as the...

Techniques for rapid design of dielectric materials with appropriate permittivity for many important technological applications are urgently needed. It is found that functional structure blocks (FSBs) are helpful in rational design of inorganic dielectrics with expected permittivity. To achieve this, coordination polyhedra are parameterized as FSBs and a simple empirical model to evaluate permi...

A technique of determination of complex permittivity and permeability of ferrimagnetic nanopowders using S-parameter measurements in rectangular waveguide and results of its study are presented in this paper. The permittivity and permeability of the ferrimagnetic nanopowders are determined by the novel technique in which magnitudes of S-parameters are used only. Use of the technique allows to s...

We investigate the effect of metal permittivity on resonant transmission of metamaterials by terahertz time-domain spectroscopy. Our experimental results on double split-ring resonators made from different metals confirm the recent numerical simulations [Phys. Rev. E 65, 036622 (2002)] that metamaterials exhibit permittivity-dependent resonant properties. In the terahertz regime, the measured i...

In this paper a method is presented for determining the complex permittivity and permeability of linear materials in the frequency domain by a single time-domain measurement; typically, the frequency band extends from VHF through X band. The technique described involves placing an unknown sample in a microwave TEM-mode fixture and exciting the sample with a subnanosecond baseband pulse. The fix...

isolated carbon nanotubes (cnts), cnt films and cnt-polymer nanocomposites are a new generation of materials with outstanding mechanical, thermal, electrical and electromagnetic properties. the main objective of this article is to provide a comprehensive review on the investigations performed in the field of characterizing electrical and electromagnetic properties of isolated cnts and cnt-reinf...