| Volumes Volume 6 Contents of Current Session |
www.adv-radio-sci.net/6/9/2008/
doi:10.5194/ars-6-9-2008
© Author(s) 2008. This work is distributed
under the Creative Commons Attribution 3.0 License.
Compact mode-matched excitation structures for radar distance measurements in overmoded circular waveguides
1Inst. für Hochfrequenztechnik und Funksysteme, Leibniz Universität Hannover, Appelstraße 9A, 30167 Hannover, Germany
2Lehrstuhl für Integrierte Systeme, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum, Germany
3Institut für Hochfrequenztechnik, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum, Germany
Abstract. This contribution deals with guided radar level measurements of liquid materials in large metal tubes, so-called stilling wells, bypass or still pipes. In the RF domain these tubes function as overmoded circular waveguides and mode-matched excitation structures like waveguide tapers are needed to avoid higher order waveguide modes. Especially for high-precision radar measurements the multimode propagation effects need to be minimized to achieve submillimeter accuracy. Therefore, a still pipe simulator is introduced with the purpose to fundamentally analyze the modal effects. Furthermore, a generalized design criterion is derived for the spurious mode suppression of compact circular waveguide transitions under the constraint of specified accuracy levels. According to the obtained results, a promising waveguide taper concept will finally be presented.
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Citation: Armbrecht, G., Denicke, E., Rolfes, I., Pohl, N., Musch, T., and Schiek, B.: Compact mode-matched excitation structures for radar distance measurements in overmoded circular waveguides, Adv. Radio Sci., 6, 9-17, doi:10.5194/ars-6-9-2008, 2008. Bibtex EndNote Reference Manager XML
