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Full-Wave Modeling of Microwave Planar Reflection Sensors for Material Moisture Testing

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Abstract

The main design aspects of two new, nearly complementary, planar reflection sensors for material moisture content measurement in the industrial environment are reported in this paper. The former is structured as a resonant microstrip ring interacting with the material under test (MUT) mainly through evanescent near fields, while the latter consists of a cavity-backed slot that couples to the MUT by radiative near fields. The sub-surface sensor-MUT interaction is numerically modeled in both cases by resorting to a full-wave electromagnetic (EM) approach based on the method of moments (MOM). If compared to the usual quasi-static approach, this method allows a more physical insight about the field-target coupling phenomena and a better accuracy in extracting the observable electrical parameters. A comparison between the two sensor types was made in order to address each sensor to its specific application field. In particular, the parametric sensitivity of both sensors to the most frequently recurring measuring artifacts was numerically analyzed. Finally, a prototype for each sensor type was constructed and experimentally tested in order to validate the results of the EM simulation.

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Authors and Affiliations

  1. Department of Electronics and Telecommunications, University of Florence, Italy

    G. Biffi Gentili & C. Riminesi

  2. Department of Electronics, Politecnico di Bari, Italy

    N. Sottani

Authors
  1. G. Biffi Gentili
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  2. C. Riminesi
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  3. N. Sottani
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Correspondence to G. Biffi Gentili.

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Biffi Gentili, G., Riminesi, C. & Sottani, N. Full-Wave Modeling of Microwave Planar Reflection Sensors for Material Moisture Testing. Subsurface Sensing Technologies and Applications 2, 453–470 (2001). https://doi.org/10.1023/A:1013277203441

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