Results 251 to 260 of about 25,320 (296)

Modeling and Measurement of Complex Permittivity of Soils in UHF

IEEE Geoscience and Remote Sensing Letters, 2020
The complex permittivity of different types of soils in the ultrahigh frequency (UHF) is studied in this letter. A new model, whose inputs are the low-frequency conductivity and the volumetric water content, is proposed to estimate the complex permittivity of soils in UHF.
John J. Pantoja, Sergio Gutierrez, Edwin Pineda, David Martinez, Christoph Baer, Félix Vega   +5 more
openaire   +1 more source

Relative complex permittivity and its dependence on frequency

World Journal of Engineering, 2017
Purpose This paper aims to give a brief overview of dielectric properties, relative complex permittivity and its dependence on frequency. The significance of different approaches to complex permittivity is also discussed.
Georgios Giannoukos, Mart Min, Toomas Rang   +2 more
exaly   +2 more sources

The theories of complex permittivity

Journal of Physics C: Solid State Physics, 1972
It is shown that the spectral density used by Scaife (1971) in his theory of complex permittivity is closely related to the autocorrelation function used by other authors and that both Scaife's equation and the equation in terms of autocorrelation functions follow immediately from the superposition principle.
openaire   +1 more source

Measurement of complex permittivity and complex permeability of materials

12th International Conference on Microwaves and Radar. MIKON-98. Conference Proceedings (IEEE Cat. No.98EX195), 2002
The time domain measurement of complex permittivity and complex permeability in the 8 to 18 GHz frequency band is considered. Some methods for determination of permittivity and permeability are presented.
H. Alenkowicz, B. Levitas
openaire   +1 more source

The complex permittivity of human tissue at microwave frequencies

Physics in Medicine and Biology, 1982
The complex permittivity, and hence the emissivity, of the body, and the attenuation coefficient of skin were determined from simple measurements made on living human tissue over the frequency range 8 to 18 GHz.
G L, Hey-Shipton, P A, Matthews, J, McStay   +2 more
openaire   +2 more sources

A spectrometer for the measurement of complex permittivity

Journal of Physics E: Scientific Instruments, 1972
The spectrometer uses an unbalanced AC bridge and records the real or imaginary component of permittivity on a chart recorder over the frequency range from about 1 Hz to 1 MHz. The measured sensitivity extends to values of loss tangent of about 10-3 although the ultimate sensitivity is expected to be higher.
I R Edmonds, M J A Smith
openaire   +1 more source

A modified calibration method for complex permittivity measurement

Review of Scientific Instruments, 2013
This work proposes a calibration method to determine the complex permittivity of materials based on the cavity-perturbation method. The method can characterize a sample with relative large in volume or high in dielectric constant, which significantly broadens the scope of the conventional perturbation method.
Hsein-Win, Chao, Tsun-Hsu, Chang
openaire   +2 more sources

Measurement of Complex Permittivity and Permeability

1970
Abstract : The program was conducted to derive a better technique for the measurement of the permeability and permittivity of lossy ferrites at microwave frequencies at temperatures up to 1000F. Although the classical method of waveguide measurement techniques was used, a careful analysis of the sources of errors was undertaken and a computer aided ...
Eva M. Thomas, Abdelnour S. Thomas
openaire   +1 more source

Six-port Complex Permittivity Measurements

2006 European Microwave Conference, 2006
This paper describes a new method of measuring the complex relative permittivity epsiv* of high-loss and low-loss materials up to the L-band in the microwave range, based on the six-port technique. The novel feature of this method is the determination of epsiv* directly from the intersection of three circles in the complex epsiv*-plane.
A.L. de Souza Rolim, A.J. Belfort de Oliveira, M.T. de Melo   +2 more
openaire   +1 more source

Waveguide Probes for Complex Permittivity Measurement

2008 14th Conference on Microwave Techniques, 2008
Paper deals with the complex permittivity measurement of biological tissues. Application of a waveguide probe for this measurement is shown. A non-destructive and non-invasive method based on reflection coefficient measurement attaching the material under test is used.
Radim Zajicek, Tomas Smejkal, Ladislav Oppl, Jan Vrba   +3 more
openaire   +1 more source