FDTD analysis of dielectric properties measurements using open-ended coaxial probes

2002 ◽  
Author(s):  
S. Bringhurst ◽  
M.F. Iskander
Keyword(s):  
Dielectric Properties ◽  
Coaxial Probes

scholarly journals Towards Non-Invasive Diagnosis of Skin Cancer: Sensing Depth Investigation of Open-Ended Coaxial Probes

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1319
Author(s):  
Cemanur Aydinalp ◽  
Sulayman Joof ◽  
Tuba Yilmaz
Keyword(s):  
Dielectric Properties ◽  
Dielectric Property ◽  
Measurement Error ◽  
Skin Cancer ◽  
Rapid Change ◽  
Biological Tissues ◽  
Tissue Heterogeneity ◽  
Low Contrast ◽  
Practical Applications ◽  
Coaxial Probes

Dielectric properties of biological tissues are traditionally measured with open-ended coaxial probes. Despite being commercially available for laboratory use, the technique suffers from high measurement error. This prevents the practical applications of the open-ended coaxial probes. One such application is the utilization of the technique for skin cancer detection. To enable a diagnostic tool, there is a need to address the error sources. Among others, tissue heterogeneity is a major contributor to measurement error. The effect of tissue heterogeneity on measurement accuracy can be decreased by quantifying the probe sensing depth. To this end, this work (1) investigates the sensing depth of the 2.2 mm-diameter open-ended coaxial probe for skin mimicking material and (2) offers a simple experimental setup and protocol for sensing depth characterization of open-ended coaxial probes. The sensing depth characterized through simulation and experiments using two double-layered configurations composed to mimic the skin tissue heterogeneity. Three thresholds in percent increase of dielectric property measurements were chosen to determine the sensing depth. Based on the experiment results, it was concluded that the sensing depth was effected by the dielectric property contrast between the layers. That is, high contrast results in rapid change whereas low contrast results in a slower change in measured dielectric properties. It was also concluded that the sensing depth was independent of frequency between 0.5 to 6 GHz and was mostly determined by the material located immediately at the aperture of the probe.

Fdtd Simulations And Analysis Of Thin Sample Dielectric Properties Measurements Using Coaxial Probes

1996 ◽  
Vol 430 ◽  
Author(s):  
S. Bringhurst ◽  
M. F. Iskander ◽  
M. J White
Keyword(s):  
High Temperature ◽  
Dielectric Properties ◽  
Frequency Band ◽  
Protective Layer ◽  
Alumina Tube ◽  
Nickel Plating ◽  
Thin Sample ◽  
Coaxial Probes ◽  
Fdtd Simulations ◽  
Complete Frequency

AbstractA metallized ceramic probe has been designed for high temperature broadband dielectric properties measurements. The probe was fabricated out of an alumina tube and rod as the outer and inner conductors respectively. The alumina was metallized with a 3 mil layer of moly-manganese and then covered with a 0.5 mil protective layer of nickel plating. The probe has been used to make complex dielectric properties measurements over the complete frequency band from 500 MHz to 3 GHz, and for temperatures as high as 1000 °C.

FDTD Simulation of an Open-Ended Metallized Ceramic Probe for Broadband High-Temperature Dielectric Properties Measurements

1994 ◽  
Vol 347 ◽  
Author(s):  
Shane Bringhurst ◽  
Magdy F. Iskander ◽  
Paul Gartside
Keyword(s):  
High Temperature ◽  
Dielectric Properties ◽  
Microwave Sintering ◽  
Fdtd Method ◽  
Fdtd Simulation ◽  
Minimum Thickness ◽  
University Of Utah ◽  
Coaxial Probes ◽  
On Line ◽  
The University

ABSTRACTOpen-ended coaxial probes have been used in broadband dielectric properties measurements for several years. To aid in the ongoing numerical simulation and microwave sintering research at the University of Utah, we have found it necessary to make dielectric properties measurements up to temperatures as high as 1400 °C. The available cavity perturbation techniques were unsuitable in this application due to their relatively narrow band, and the available metal probes are also unsuitable due to the differential thermal expansions of the inner and outer conductors, which makes it difficult to carry out accurate and on-line calibration procedures for these probes.To help us achieve both broadband and high-temperature dielectric properties measurements, we have developed a new metallized ceramic coaxial probe. The detailed design of this probe is described and the metallization procedure is discussed.Also to optimize the design of the probe and in particular to increase the penetration of fields in samples under test and hence improve the probe sensitivity to variation in properties of a larger class of materials, and to determine the required minimum thickness of various samples to obtain accurate results, we modeled and simulated the probe performance using the Finite-Difference Time-Domain (FDTD) method. Results from the FDTD simulation are presented and some guidelines that may be used to optimize the design of the probe are discussed.

scholarly journals Towards Accurate Microwave Characterization of Tissues: Sensing Depth Analysis of Open-Ended Coaxial Probes with Ex Vivo Rat Breast and Skin Tissues

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 338
Author(s):  
Cemanur Aydinalp ◽  
Sulayman Joof ◽  
Tuba Yilmaz
Keyword(s):  
Dielectric Properties ◽  
Dielectric Property ◽  
Classification Accuracy ◽  
Ex Vivo ◽  
Error Source ◽  
Aperture Diameter ◽  
Depth Analysis ◽  
Coaxial Probes ◽  
Measurement Results ◽  
Destructive Measurement

Dielectric properties of biological materials are commonly characterized with open-ended coaxial probes due to the broadband and non-destructive measurement capabilities. Recently, potential diagnostics applications of the technique have been investigated. Although the technique can successfully classify the tissues with different dielectric properties, the classification accuracy can be improved for tissues with similar dielectric properties. Increase in classification accuracy can be achieved by addressing the error sources. One well-known error source contributing to low measurement accuracy is tissue heterogeneity. To mitigate this error source, there is a need define the probe sensing depth. Such knowledge can enable application-specific probe selection or design. The sensing depth can also be used as an input to the classification algorithms which can potentially improve the tissue classification accuracy. Towards this goal, this work investigates the sensing depth of a commercially available 2.2 mm aperture diameter probe with double-layered configurations using ex vivo rat breast and skin tissues. It was concluded that the dielectric property contrast between the heterogeneous tissue components has an effect on the sensing depth. Also, a membrane layer (between 0.4–0.8 mm thickness) on the rat wet skin tissue and breast tissue will potentially affect the dielectric property measurement results by 52% to 84%.

SYNTHESIS AND DIELECTRIC PROPERTIES OF LIQUID CRYSTALS CONTAINING TWO CYANO GROUPS

1979 ◽  
Vol 40 (C3) ◽  
pp. C3-37-C3-40
Author(s):  
L. A. KARAMYSHEVA ◽  
S. I. TORGOVA ◽  
E. I. KOVSHEV ◽  
M. I. BARNIK
Keyword(s):  
Liquid Crystals ◽  
Dielectric Properties ◽  
Cyano Groups

Investigation of Dielectric Properties of (1-x) Ni0.53Cu0.12Zn0.35Fe1.88O4 ferrite + (x) Gd0.2Ce0.8O3 for Multilayer Chip Inductors

2012 ◽  
Vol 03 (1) ◽  
pp. 71-73
Author(s):  
S. Bharadwaj ◽  
◽  
Suman Kumar Burnwal ◽  
T. Ramesh ◽  
S.R. Murthy ◽  
...  
Keyword(s):  
Dielectric Properties
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