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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: [email protected]
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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

REFERENCES

[1]Brumbi, D.: Measuring process and storage tank level with radar technology, in Record of the IEEE 1995 Int. Radar Conf., May 1995, 256–260.Google Scholar
[2]Armbrecht, G.; Denicke, E.; Rolfes, I.; Pohl, N.; Musch, T.; Schiek, B.: Compact mode-matched excitation structures for radar distance measurements in overmoded circular waveguides. Ad. Radio Sci., 6 (2008), 9–17. Available Online at http://www.adv-radio-sci.net/6/9/2008/Google Scholar
[3]Pohl, N.; Gerding, M.; Will, B.; Musch, T.; Hausner, J.; Schiek, B.: High precision radar distance measurements in overmoded circular waveguides. IEEE Trans. Microw. Theory Tech., 55 (6) (June 2007), 1374–1381.Google Scholar
[4]Armbrecht, G.; Denicke, E.; Pohl, N.; Musch, T.; Rolfes, I.: Obstacle based concept for compact mode-preserving waveguide transitions for highprecision radar level measurements, in 38th European Microwave Conf. EuMC 2008, October 2008, 472–475.CrossRefGoogle Scholar
[5]Denicke, E.; Armbrecht, G.; Rolfes, I.: A correlation-based method for precise radar distance measurements in dispersive waveguides, in 6th European Radar Conf. EuRAD 2009, September/October 2009, 302–305.Google Scholar
[6]Fernandez Casares, S.; Balle, S.; Menendez-Valdes, P.: Mode beating and spontaneous emission noise effects in a variable-waveguide model for the dynamics of gain-guided semiconductor laser arrays. IEEE J. Quantum Electron., 30 (11) (November 1994), 2449–2457.Google Scholar
[7]Marcuse, D.: Theory of Dielectric Optical Waveguides, 2nd ed., ser. Quantum Electronics – Principles and Applications, Academic Press Boston, 1991.Google Scholar
[8]Liu, M.; Shum, P.: Effects of intermodal dispersion on short pulse propagation in an active nonlinear two-core fiber coupler. IEEE Photon. Technol. Lett., 16 (4) (April 2004), 1080–1082.Google Scholar
[9]Skolnik, M.: Radar Handbook, McGraw-Hill New York, 2008.Google Scholar
[10]Roberts, M.J.: Signals and Systems: Analysis Using Transform Methods and MATLAB, McGraw-Hill New York, 2004.Google Scholar
[11]Tang, C.: Mode conversion in tapered waveguides at and near cutoff. IEEE Trans. Microw. Theory Tech., 14 (5) (1966), 233–239.Google Scholar