Recent advances in satellite remote sensing at near-millimeter and sub-millimeter wavelengths (~100-3000 GHz) require accurate complex permittivity for ice and liquid water at these frequencies for different temperatures, especially for cold atmospheric conditions. This paper summarizes the existing experimental permittivity data in the literature, and provides an updated empirical ice permitti...

In transmission-reflection method, the microstrip transmission line coated with an organic polymer as an overlay is used to estimate the permittivity of the polymer film. Scattering parameter response of the microstrip line varies as the permittivity of the overlay or its thickness changes. The permittivity is estimated by minimizing the difference between the theoretical (computed from the ana...

Silicon carbide (SiC) is widely used to improve the non-linear conductivity of resistive field grading composite. In this paper, SiC nanoparticles are modified into core-shell with silica (SiO2) coating on surface and characterised by transmission electron microscopy X-ray diffraction, respectively. The 7 wt% [email protected]2/epoxy nanocomposite then prepared, pure epoxy SiC/epoxy prepared as...

The increasing use of computer-based software packages for designing RF/microwave circuits requires very accurate data about dielectric properties of materials used in the design. This paper presents results of precise measurements of relative permittivity and loss tangent of alumina substrates and Fodel dielectric 6050 used in thick-film photoimageable technology for fabricating microwave doub...

Thermal ionization of alkali species emitted from thermally decomposing vegetative matter into the combustion zone of a fire makes the zone a weakly ionized gaseous medium. Collision between the medium electrons and neutral flame particles is a dominant form of particle interaction and incident microwave energy absorption process. Electromagnetic wave absorption properties of vegetation fire ha...

We assess the influence of a radius and relative permittivity an isotropic dielectric sphere on electric field homogeneity. The homogenous is generated using two thin toroidal electrodes, charged by equal charges opposite signs. Poisson equation solved method separation variables. Increase in its radius, produces more distortions

(1) and c is the speed of light in vacuum. Estimate the time-average power P (i.e., the radiation) that escapes from the end of the cable using vector (or scalar) Huygens-Kirchhoff diffraction theory for the case that the cable is excited with a TEM wave with λ b. Compare the cases of a coaxial cable by itself, and one with its outer conductor attached to a ground plane such that the radiation ...

The goal of this paper is to use polymer-based materials (instead of hard ceramics) in fabrication of dielectric resonator antennas at millimeter-wave frequencies. The soft nature of polymers facilitates machining of antennas, while the low permittivity of polymers naturally enhances the bandwidth. More importantly, advantageous properties (e.g., flexibility and photosensitivity) of some polyme...

BACKGROUND Despite the high incidence of breast cancer worldwide, methods for early non-invasive diagnosis and sensitive and specific prognostic evaluation remain difficult. In this study, we investigated microwave parameters as a potential non-invasive approach to detect breast cancer. METHODS Samples of freshly excised breast tissues (n = 509) from 98 patients were identified as normal, ben...

Anion affinities, gammaX-, for the aerial interface of aqueous (Br- + NO3- + I- + SCN- + BF4- + ClO4-) solutions are determined by electrospray ionization mass spectrometry. The composition of the ions ejected from the surface of fissioning nanodroplets shows that gammaX- increase (decrease) exponentially with anionic radii, aX-(dehydration free energies, dGX-), and selectively respond to the p...