Start Date

2016 12:00 AM

Description

A method for characterizing the dielectric properties of multilayer low-conductivity structures using an X-band (8 to 12 GHz) patch antenna sensor is developed. The dominant mode resonant frequency of the patch antenna depends on its own electrical and geometrical parameters and on the permittivity and geometry of a material-under-test. A forward model for calculating resonant frequency and quality factor of the patch is validated by comparing calculated values of resonant frequency and quality factor with values measured on a variety of materials with well-characterized dielectric properties in the X-band. Excellent agreement between calculated and measured values of sensor resonant frequency was obtained for the samples studied, e.g. Table 1, while moderate agreement was found between calculated and measured quality factor values, as it incurred the particular challenge of accurately quantifying multiple contributions to loss from the sensor structure itself. Further, a patch antenna sensor was designed according to constraints such as desirable dimensions and frequency of operation. From measured resonant frequency and quality factor, the dielectric properties of test-pieces were inferred with good accuracy in the case of the dielectric constant and with more uncertainty in the case of the loss factor, again due to unquantifiable loss contributions from the sensor itself.

Table 1. Calculated, measured and simulated resonant frequencies, fr, for a patch sensor designed to resonate within the X-band, for the patch sensor in contact with various samples with dielectric constant increasing from 3.00 (RO3003) to 9.80 (TMM10i). Errors are calculated based on differences between the modeled fr and that measured or that simulated by ANSYS HFSS (High Frequency Structural Simulator).

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

An X-Band Patch Antenna Sensor for Quantitative Dielectric Characterization of Stratified Low-Conductivity Media

A method for characterizing the dielectric properties of multilayer low-conductivity structures using an X-band (8 to 12 GHz) patch antenna sensor is developed. The dominant mode resonant frequency of the patch antenna depends on its own electrical and geometrical parameters and on the permittivity and geometry of a material-under-test. A forward model for calculating resonant frequency and quality factor of the patch is validated by comparing calculated values of resonant frequency and quality factor with values measured on a variety of materials with well-characterized dielectric properties in the X-band. Excellent agreement between calculated and measured values of sensor resonant frequency was obtained for the samples studied, e.g. Table 1, while moderate agreement was found between calculated and measured quality factor values, as it incurred the particular challenge of accurately quantifying multiple contributions to loss from the sensor structure itself. Further, a patch antenna sensor was designed according to constraints such as desirable dimensions and frequency of operation. From measured resonant frequency and quality factor, the dielectric properties of test-pieces were inferred with good accuracy in the case of the dielectric constant and with more uncertainty in the case of the loss factor, again due to unquantifiable loss contributions from the sensor itself.

Table 1. Calculated, measured and simulated resonant frequencies, fr, for a patch sensor designed to resonate within the X-band, for the patch sensor in contact with various samples with dielectric constant increasing from 3.00 (RO3003) to 9.80 (TMM10i). Errors are calculated based on differences between the modeled fr and that measured or that simulated by ANSYS HFSS (High Frequency Structural Simulator).