0.05-3 GHz VNA characterization of soil dielectric properties based on the multiline TRL calibration

• Published in: Measurement science & technology Vol. 28; no. 2; pp. 24007 - 24013
• Main Authors: Lewandowski, Arkadiusz, Szyp owska, Agnieszka, Kafarski, Marcin, Wilczek, Andrzej, Barmuta, Pawe, Skierucha, Wojciech
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.02.2017
• Subjects: multiline through-reflect-line calibration; soil relative dielectric permittivity; vector network analyzer
• ISSN: 0957-0233; 1361-6501; 1361-6501
• DOI: 10.1088/1361-6501/28/2/024007

We present a methodology for characterization of soil relative dielectric permittivity in the frequency range 0.05-3 GHz. Soil samples are placed in a measurement cell constructed out of a EIA 1-5/8" coaxial transmission line, and then measured with a calibrated vector-network-analyzer. From these measurements the relative dielectric permittivity is obtained by use of a modified Boughriet algorithm. In order to calibrate the vector-network-analyzer directly at the EIA 1-5/8" coaxial-transmission-line measurement planes, we use the multiline through-reflect-line method. This method, while providing superior vector-network-analyzer calibration accuracy, is also easy to implement since it uses only transmission lines with known lengths and a single unknown highly-reflective termination. The implemented calibration method was compared to a simplified approach that uses the standard SOLT calibration in Type-N reference planes, and then accounts for the Type-N/EIA 1-5/8" adapters by removing their electrical delay. Experimental results for teflon and soil samples with different moisture content and salinity confirmed the validity of our approach.