16th International Conference
on Microwave and High Frequency Heating

18-21 September 2017, Delft, The Netherlands
09:45   Dielectric properties measurement (1)
Chair: Jose Fayos-Fernandez
09:45
15 mins
EVALUATION OF THE DIELECTRIC PROPERTIES OF CATALYTIC CANDIDATES FOR METHANE CONVERSION UNDER MW-HEATING
Ignacio Julian, Gabriel Llorens-Vallés, Pedro Plaza-González, Beatriz García-Baños, José Luis Hueso, Reyes Mallada, Jesús Santamaría
Abstract: Evaluation of the dielectric properties of multiple MW-absorbing catalytic powders and monoliths selected as potential candidates for their use in the non-oxidative coupling of methane (MNOC) at high temperatures.
10:00
15 mins
SPLIT CAVITY DIELECTRIC MEASUREMENTS AT DIFFERENT HARMONICS
Felipe Penaranda-Foix, David Marqués-Villarroya, José M. Catalá-Civera
Abstract: This paper deals with the possibility of measuring at different resonant frequencies harmonics of TE0nd modes the permittivity of planar substrates with a split cavity setup. The analysis is performed by circuit method and makes the methods based on resonant cavities more powerful because the covered band is increased with more resonant frequencies.
10:15
15 mins
MEASUREMENT OF COMPLEX PERMITTIVITTY USING AZHIMUTAL MODES IN A SPLIT CAVITY
David Marqués-Villarroya, Felipe Penaranda-Foix, Beatriz García-Baños, Antoni J. Canós
Abstract: Dielectric characterization of materials is crucial to design any microwave power system or heating process. The split cylinder cavity is commonly used to obtain the dielectric constant and loss tangent of laminar materials because of its ease of manufacture and non-destructive testing. Usually, the modes employed in this type of cavity are TE0np [1], however, other modes with azimuthal variation can be used too, widening the range of characterization. For this purpose, a full-wave modeling of the cavity must be used [2], where the whole set of modes, TEmnp and TMmnp, are taken into account. In this work, we characterize the dielectric properties of some different materials in a broader bandwidth because of the use of azimuthal modes. The technical changes of the coupling for the excitation of the azimuthal modes are addressed, and the measurements of resonant frequencies and quality factors are provided, with which the dielectric constant and the loss tangent are indirectly obtained. For the first time, the dielectric constant and loss tangent have been characterized making use of azimuthal modes. With this improvement, we can enlarge notably the characterization bandwidth, as well as improve the accuracy of the computed dielectric properties.