In this work, two electromagnetic models are used for the characterization of a planar structure including a flat, thick copper conductor. Indeed the first model is consisted by modeling two metal ribbons without bulkiness, placed one above the other at a distance of h2 equal to the thickness of the thick conductor. This approach has been implemented and tested by the iterative method. The resu...

The complex permittivity of target has a crucial influence on its microwave radiation characteristics. In the quantitative research of microwave remote sensing, the study of the dielectric properties of vegetation to establish the relationship between its specific physical parameters and complex permittivity is the basic work in this field. In this study, corn leaves samples of different types ...

An adjustable resonance cavity was developed to measure the complex permittivity of dielectric materials. The cavity has an inner diameter of 16.400 cm and an inner height of 2.54 cm. The aluminum stationary wall holder was positioned about 10.8 cm above the top of the cavity. It was fixed into place by three 1.27-cm-diam linear shafts. By suspending from the wall holder, the movable wall moved...

759 Soil water content (θ, m3 m−3) is a basic hydrologic parameter that affects groundwater recharge, surface water fl ow, transpiration, and carbon fi xation. Electronic monitoring of θ facilitates the study of those processes by providing detailed temporal data. Most instruments currently in use measure soil dielectric permittivity, directly or indirectly, and then calculate θ with an equatio...

The pull-in voltage instability associated with a simple MEMS device, consisting of a thin dielectric elastic membrane supported above a rigid conducting ground plate, is analyzed. The upper surface of the membrane is coated with a thin conducting film. In a certain asymptotic limit representing a thin device, the mathematical model consists of a nonlinear partial differential equation for the ...

We report enhancement of the dielectric permittivity of poly(vinylidene fluoride) (PVDF) generated by depositing magnetic iron oxide (Fe3O4) nanoparticles on the surface of barium titanate (BT) to fabricate BT-Fe3O4/PVDF composites. This process introduced an external magnetic field and the influences of external magnetic field on dielectric properties of composites were investigated systematic...

An analytical model of a composite dielectric presented in this paper is the extension of Maxwell Garnett formulation. It takes into account the simultaneous statistical (Gaussian) distribution of conductivity and aspect ratio of inclusions. The inclusions are randomly oriented elongated conducting spheroids at concentrations below the percolation threshold. The formulation presented herein is ...

Poly(2-nonyl-2-oxazoline)80-stat-poly(2-dec-91-enyl-2-oxazoline)20 and poly(2-dec-91-enyl2-oxazoline)100 can be synthesized from the cationic ring-opening polymerization of monomers that can be derived from fatty acids from renewable resources. These (co)poly(2-oxazoline)s can be crosslinked with diand trifunctional mercapto compounds using the UV-induced thiol-ene reaction. The complex permitt...

The paper deals with the problem of reconstruction of microstructural information from known effective complex permittivity of a composite material. A numerical method for recovering geometric information from measurements of frequency dependent effective complex permittivity is developed based on Stieltjes analytic representation of the effective permittivity tensor of a two-component mixture....

The paper discusses characteristics of a new modeling-based technique for determining dielectric properties of materials. Complex permittivity is found with an optimization algorithm designed to match complex S-parameters obtained from measurements and from 3D FDTD simulation. The method is developed on a two-port (waveguide-type) fixture and deals with complex reflection and transmission chara...