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Time-Domain Free-Field Measurements of the Relative Permittivity of Building Materials



Chriss A. Grosvenor, Robert Johnk, James R. Baker-Jarvis, Michael D. Janezic, Billy F. Riddle


Free-field measurements were made on several materials using dual-ridged guide antennas and 1 m x 1 m samples placed on an optical table loaded with absorber. The samples were polycarbonate, gypsum, plywood, a brick wall, and a concrete wall. This paper will discuss the use of time-gating to isolate a samples front and back surfaces to obtain the measured reflection and transmission coefficients. Theoretical reflection and transmission equations are generated from a plane wave model. Relative permittivity is obtained by varying the parameters in the Cole-Davidson equation until a best fit between the theoretical and measured reflection coefficients is obtained.
IEEE Transactions on Instrumentation and Measurement


Antennas, Cole-Davidson equation, digital signal-processing, free-space measurements, relative permittivity


Grosvenor, C. , Johnk, R. , Baker-Jarvis, J. , Janezic, M. and Riddle, B. (2009), Time-Domain Free-Field Measurements of the Relative Permittivity of Building Materials, IEEE Transactions on Instrumentation and Measurement, [online], (Accessed February 24, 2024)
Created June 10, 2009, Updated June 2, 2021