This page provides free access to publications, reports, data, and computer codes that I hope other researchers will find useful.  Please feel free to contact me if you have questions about any of the material you find here.

Background

My work in material characterization began around 2017, when I became interested in characterizing indoor propagation in the 24 GHz ISM band.  Given the availability of cheap automotive radar chipsets in this band, I was interested in seeing if the same band could be used for communications, possibly representing an alternative to existing 2.4 GHz and 5 GHz WLAN standards.  The main question was whether transmission losses would be modest enough to allow non-line-of-sight (NLOS) communications, similar to what is possible at the usual microwave bands.

One problem we ran into early in that research was the lack of published building material properties at 24 GHz, which we needed to compare our propagation measurements with ray-tracing predictions.  With the aid of a generous MRI grant from the NSF, we were able to acquire the equipment needed to do careful free-space complex permittivity measurements of common building materials (drywall, glass, brick, concrete, plywood, and oriented strand board) over the complete 4-40 GHz range.  We were particularly interested in understanding if there a significant difference in material properties when moving from the microwave to millimeter wave (mm-wave) regimes.

4-40 GHz Complex Permittivity Measurements

Publications

J. Wallace, R. Mehmood, and J. Abel, “4-40 GHz Complex Permittivity Measurements of Common Building Materials,” Technical Report,Nov., 2020. [pdf]

Data and Computer Codes

4-40 GHz Measurement data, November 2020.  [zip]

MATLAB Processing Scripts, November 2020.  [zip]

GPU Permittivity Fitting Code, November 2020.  [zip]