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Radar distance measurements in circular waveguides involving intermodal dispersion effects

Published online by Cambridge University Press:  25 June 2010

Eckhard Denicke ,
Gunnar Armbrecht  and
Ilona Rolfes
Eckhard Denicke*
Affiliation:
Institute of Radiofrequency and Microwave Engineering, Leibniz Universität Hannover, Appelstr. 9A, 30167 Hannover, Germany.
Gunnar Armbrecht
Affiliation:
Institute of Radiofrequency and Microwave Engineering, Leibniz Universität Hannover, Appelstr. 9A, 30167 Hannover, Germany.
Ilona Rolfes
Affiliation:
Institute of Radiofrequency and Microwave Engineering, Leibniz Universität Hannover, Appelstr. 9A, 30167 Hannover, Germany.
*
Corresponding author: E. Denicke Email: denicke@hft.uni-hannover.de
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Abstract

This contribution deals with guided radar distance measurements in the field of industrial tank level control. The aim is to achieve a submillimeter gauging accuracy even when conducting the measurement within a highly dispersive environment of large and thus overmoded circular waveguides. Normally, multimode propagation causes a decrease in measurement precision. Therefore, the effects of intermodal dispersion are fundamentally reviewed and, based on these results, a correlation-based signal processing method is presented. This method is able to exploit the otherwise parasitic dispersion effects to enhance the measurement precision even in constellation with a simple waveguide transition or antenna, respectively. Furthermore, considerations on the mode variety and its influence on the signal complexity as well as investigations on the technique's reliability and accuracy are presented. Measurement results in a frequency range of 8.5–10.5 GHz are provided for three different kinds of waveguide transitions proving the capability of the method.

Keywords

Radar distance measurementLevel measurementRadar signal processingCorrelationOvermoded circular waveguidesMultimode waveguidesIntermodal dispersion
Type
Original Article
Information
International Journal of Microwave and Wireless Technologies , Volume 2 , Special Issue 3-4: European Microwave Week 2009 , August 2010 , pp. 409 - 417
Copyright
Copyright © Cambridge University Press and the European Microwave Association 2010

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References

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