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Microwave Tomography (MWT) is being developed as an accurate detection of hemorrhagic strokes using microwaves. A transmission line technique is used to measure the relative permittivity of blood as a function of frequency and is presented to provide insight on an appropriate operating frequency for MWT. A response calibration method is used on a coaxial sample holder to accurately measure the scattering...
Methods for determining the dielectric permittivity of rock samples at millimetre wave frequencies have been investigated. A quasi-optical approach using pellets of powdered samples was found to work well, avoiding the dimensional restrictions of small waveguides. The permittivity of volcanic rock and ash samples was measured, providing valuable data for MMW radar remote sensing of terrain and ash...
A simple non-destructive method for determination of dielectric properties of arbitrary wall in building is presented. The free space method is based on the measurements of reflection coefficients for different angles of incidence. The walls constructed of unknown materials are modeled as homogenous dielectric plate with smooth surface. The measurements are made for the frequency of 2.4 GHz so the...
In this paper, we present a novel ultra-fast system for continuously monitoring the electrical parameters of a microwave cavity resonator, which can be used to assess the complex dielectric constant of a time-variant material sample within the resonator. The resonator is excited near a selected resonance mode by a digitally generated multisine signal. A receiver system using a Fast Fourier Transform...
The propagation of electromagnetic waves in indoor environments is strongly influenced by reflectivity and transmissibility of building construction materials. This paper describes a free-space measurement technique for determining the complex dielectric constant and loss tangent of existing walls in building. The measurement setup was consisted of Vector Network Analyzer (VNA) and two horn antennas...
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