Contents
An exact solution of the discontinuity problem of a circular cylindrical dielectric post centered in a rectangular waveguide is presented. The waveguide is divided in three regions where the field is expressed in cylindrical waves or in waveguide modes. By point matching, a system of linear equations determining the reflection and transmission coefficients is found. — The structure of our interest includes a liquid column surrounded by a cylindrical glass tube. For this case, curves have been made showing the relationship between the coefficients of reflection and transmission and the permittivity of the rod. Such curves are used for measuring the dielectric properties of liquids.
Übersicht
Für das Problem einer durch einen dielektrischen Stab in einem rechteckigen Wellenleiter verursachten Diskontinuität wird eine exakte Feldlösung angegeben. Der Wellenleiter wird dabei in drei Bereiche eingeteilt, in denen das Feld in Form von Zylinderwellen oder Wellenleitermoden ausgedrückt wird. — Durch punktförmige Anpassung wird ein System linearer Gleichungen gefunden, aus dem sich Reflexions- und Transmissionskoeffizienten bestimmen lassen. — Als Anwendungsbeispiel wird eine Flüssigkeitssäule in einem zylindrischen Glasrohr untersucht. Für diesen Fall werden Diagramme angegeben, aus denen die Beziehungen zwischen den Transmissions- und Reflexionsfaktoren zu den dielektrischen Konstanten der Probe entnommen werden können. — Solche Kurven werden zur Messung der dielektrischen Eigenschaften von Flüssigkeiten benutzt.
Similar content being viewed by others
References
Marcuwitz, N.: Waveguide Handbook. New York: McGraw-Hill 1951
Lewin, L.: Advanced theory of waveguides. London: Iliffe 1951
Franklin, R. N.; Bryant, G. H.: Cylindrical capacitive Obstacles in a Waveguide. Proc. IEE. 110 (1963) 1709–1719
Bryant, G. H.; Franklin, R. N.: Scattering from a Bounded Plasma. Proc. Phys. Soc. 81 (1963) 531–543 and 790
Bryant, G. H.; Franklin, R. N.; Potok, M. H. N.: The Equivalent circuit of a plasma. IEEE. Trans. Microwave Theory Tech. 12 (1964) 469–470
Suzuki, M.: Dielectric elements in a rectangular waveguide. (in Japanese). J. Inst. Electr. Commun. Eng. Japan. 38 (1955) 22
Nielsen, E. D.: Scattering by a cylindrical post of complex permittivity in a waveguide. IEEE Trans. Microwave Theory Tech. 17 (1969) 148–153
Lewin, L.: On the inadequacy of discrete mode-matching techniques in some waveguide discontinuity problems. IEEE Trans. Microwave Theory Tech. 18 (1970) 364–372
Roberts, S.; Hippel von, A. R.: A new method for measuring dielectric constant and loss in the range of centimeter waves. J. Appl. Phys. 17 (1946)
Surber, W. H.; Crouch, G. E.: Dielectric measurement methods for solids at microwave frequencies. J. Appl. Phys. 19 (1948) 1130–1139
Hippel von, A. R. (ed.) Dielectric materials and applications. Cambridge Massachusetts: M.I.T. press 1966
Stogryn, A.: Equations for calculating the dielectric constant of saline water. IEEE Trans. Microwave Theory Tech. 19 (1971) 733–736
Cook, H. F.: A comparison of the dielectric behaviour of pure water and human blood at microwave frequencies. Brit. J. Appl. Phys. 3 (1952) 249–255
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Gotsis, N., Vafiadis, E.E. & Sahalos, J.N. The discontinuity problem of a cylindrical dielectric post in a waveguide and its application on the dielectric constant measurements of liquids. Archiv f. Elektrotechnik 68, 249–257 (1985). https://doi.org/10.1007/BF01845936
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01845936