recent technological improvements have extended the application range of dielectric permittivity biomass measurements to on-line monitoring of physiological changes during bacterial fermentations. in an industrial fermentation of bacillus thuringiensis, it is important to verify the intactness of bacterial plasmid content in all steps of culture. changes in certain plasmid resident properties o...

An infinitely flanged coaxial line is analytically solved with the mode-matching technique and Green’s function to propose a precise yet fast-convergent scattering solution for complex permittivity measurement. Based on virtual current cancelation, we formulate the open half-space fields in terms of coaxial modes and related Green’s functions and thus obtain the simultaneous equations with rapi...

Techniques based on the perturbation of cavity resonators are commonly used to measure the permittivity and permeability of samples of dielectric and ferrite materials at microwave frequencies. They are also used to measure the local electric and magnetic field strengths in microwave structures including the shunt impedances of cavity resonators and the coupling impedances of slow-wave structur...

An accompanying numerical simulation for obtaining field patterns, resonant frequencies, and the Q factor is proposed to evaluate the experimental conditions of complex permittivity reconstruction by the perturbation method and thereby improve its accuracy and flexibility. This approach is illustrated by analyzing the measurement of dielectric constant and the loss tangent of wet movie film in ...

We consider a coefficient inverse problems for the Maxwell’ system in 3-D. The coefficient of interest is the dielectric permittivity function. Only backscattering single measurement data are used. The problem is formulated as an optimization problem. The key idea is to use the adaptive finite element method for the solution. Both analytical and numerical results are presented. Similar ideas fo...

The rectangular dielectric waveguide (RDWG) technique has been previously described for the determination of complex permittivity of a wide class of dielectric materials of various thicknesses and cross sections. This paper presents a unified RDWG technique for the determination of the dielectric constant of materials. Some measurement results are reported in the W -band frequencies to demonstr...

tiveness of TDR. However, the emergence of low-cost, high-frequency oscillators has led to an increased interThe capacitance (CAP) method and time domain reflectometry est in CAP techniques (e.g., Dean et al., 1987; Evett (TDR) are two popular electromagnetic techniques used to estimate soil water content. However, the frequency dependence of the real and Steiner, 1995; Paltineanu and Starr, 19...

A new configuration of dielectric-loaded resonator (DR), particularly versatile for the complex permittivity measurement substrates microwave circuits, even in presence back metal plates, is shown here. To test this technique a wide interval values permittivity, versatility 3-D printing exploited to print samples with different densities, thus artificially changing effective (1.7–3.1) real part...

Dielectric spectroscopy is useful for the characterization of colloidal dispersions. In the past, dielectric spectroscopy has been attempted using parallel metal electrodes to measure the permittivity and conductivity of colloids. However, it is difficult in practice to make these measurements in conductive solutions because large measurement errors can be caused by electrode polarization, whic...

Tomographic diffraction microscopy is a three-dimensional quantitative optical imaging technique in which the sample is numerically reconstructed from tens of holograms recorded under different angles of incidence. We show that combining the measurement of the amplitude, the phase, and the polarization of the field scattered by the sample with an approximate knowledge of the sample permittivity...