A compact planar cylindrical resonant RF sensor for the characterization of dielectric samples. Issue 13 (2nd September 2019)

• Record Type: Journal Article
• Authors: Varshney, Prashant Kumar; Akhtar, M. Jaleel
• Is Part Of: Journal of electromagnetic waves and applications. Volume 33:Issue 13(2019)
• Page Start: 1700
• Page End: 1717
• Publication Date: 2019-09-02
• Subjects: Characterization -- cylindrical resonator -- dielectric constant -- microwave sensor -- permittivity measurement -- perturbation method -- planar; Electromagnetic waves -- Periodicals; Electromagnetic devices -- Periodicals; 621.3
• DOI: 10.1080/09205071.2019.1630325
• Languages: English
• ISSNs: 0920-5071

Abstract

ABSTRACT: A conventional cavity-based planar cylindrical resonant sensor for the RF characterization of dielectric materials is proposed in this work. The designed planar cylindrical sensor is about 22% more compact providing 25% higher sensitivity as compared to its rectangular counterpart working at the same frequency. The proposed sensor is designed for the fundamental TM010 mode at 1.5 GHz resonant frequency and is excited using the coaxial probe instead of conventional microstrip feeding, which aids in obtaining further compactness. The sensor is designed on low-cost FR4 substrate and experimentally validated using various dielectric samples like Teflon, polyethylene, PVC and plexiglass yielding a good match between the retrieved dielectric constants and data available in the literature. For characterization of dielectrics, a slot is drilled at the center of the sensor having the maximum electric field for inserting the test sample and later optimized for higher sensitivity. For determining the loss tangent in terms of the transmission coefficient at the resonant frequency, a numerical model is derived using the curve fitting technique.