Methoden zur Nahfeldmessung elektromagnetischer Störfeldaussendungen
Zusammenfassung der Projektergebnisse
Within this research project methods for the near-field measurement of electromagnetic interference radiated by electric and electronic devices and methods for the modeling of the propagation of radiated electromagnetic interference have been developed. Since the radiated electromagnetic interferences are stochastic fields, amplitude and phase amplitudes of the field components cannot be determined by measurement. Due to the missing phase information it is not possible to compute from the measured near-field distribution the resulting field distribution when the device under test is embedded in a certain environment. To solve this problem a method for computing the spectral energy density of stationary stochastic electromagnetic fields has been developed and, furthermore, a measurement instrumentation based upon this method has been developed and investigated experimentally. In the developed methodical framework the stochastic electromagnetic field is described by correlation dyadics characterizing the correlation spectra of the electric or magnetic field components at two points of space. Stationary stochastic electromagnetic fields with Gaussian probability distribution can be completely described by these correlation dyadics. To characterize the sources, the stochastic EM field is simultaneously scanned with two electric or magnetic field probes. This is performed with a computer controlled two-point scanning system for automatic recording of near-field data by two-point scanning, developed in this project. In a grid of sampling points above the device under test the field amplitudes are recorded with a digital sampling oscilloscope in pairs of grid points. From these records the autocorrelation functions for all field samples and the cross correlation functions for all pairs of field samples are computed. From these near-field auto- and cross correlation dyadics the spectral energy densities in the environment are computed. The methods also were extended for cyclostationary stochastic electromagnetic fields. The correlation dyadics describing the radiated stochastic electromagnetic field are related to the correlation dyadics of the excitation currents via Green’s functions. The Green’s functions method was applied for the analytic computation of the near-field and far-field of the radiated EMI of stochastic sources. On the basis of the Method of Moments (MoM), a scheme for numerical modeling of stochastic EM fields was established. Using MoM, the EM field problem is converted into a network problem based on correlation matrix methods for the analysis of linear noisy networks. The Correlation Transmission Line Matrix (CTLM) method for time-domain computation of the auto- and cross correlation functions (ACFs and CCFs) of stationary stochastic electromagnetic was developed. For a compact description of the sampled field data by correlation matrices the principal component analysis (PCA) for eigenvalue decomposition was introduced. We expect the development of near-field stochastic field measurement systems that will facilitate an accurate modeling of the EMI radiated into complex environments. Future research in further developing measurement methods and equipment as well as in developing analytical and numerical tools for the modeling stochastic electromagnetic fields is planned. Near-field scanners for stochastic electromagnetic fields together with CAD design software will have a high impact on the EMI-aware modeling of circuits and systems. Since EMI-aware CAD and computer-aided fabrication has the potential for reducing time-to-market and saving costs the application of EMI-aware CAD will be highly attractive. The research on methods for near-field measurement of radiated electromagnetic interference will be continued within the European research project NEMF21. In the European research project NEMF21 the companies CST GmbH, Darmstadt and IMST GmbH, Kamp-Lintfort, both are project partners. Both companies are interested to include algorithms for the modeling of stochastic EM fields in their CAD tools. This will guarantee a wide dissemination of the simulation tools in the microwave and EMC communities. This project has succeeded in further developing the disciplines of electromagnetic field theory, network theory and stochastic signal theory in close cooperation. The application of the network theory of noisy circuits to field theory yielded powerful methods for the analytic and numerical analysis of stochastic electromagnetic fields. The network theory of noisy electromagnetic fields is constitutive for a physics-based network theory of wireless communications to be investigated in the European research project NEMF21. Together with Prof. Dr. Andreas Thiede from the Institut für Höchstfrequenztechnik from the University of Paderborn we plan a research project based on further miniaturization of the sampling probes by using integrated electric dipole and magnetic loop probes together with active electronics in AlGaAs/GaAs-HEMT and SiGe:C-HBT technologies, as discussed in Article “Near-field measurement of stochastic electromagnetic fields”, in: IEEE Electromagnetic Compatibility Magazine, vol. 4, no. 3, pp. 79–85, Nov 2015.
Projektbezogene Publikationen (Auswahl)
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Imaging of sources of radiated electromagnetic interference.
Frequenz - Journal of RF-Engineering and Telecommunications, Vol. 65. 2011, Heft 9-10, pp. 261–265.
J. A. Russer, P. Russer
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Stochastic wave sensing with logarithmic periodic circular antenna Arrays. In: 2012 International Conference on Electromagnetics
in Advanced Applications (ICEAA), Sep. 2012, pp. 622 –625.
J. Russer, G. Scarpa, P. Lugli, P. Russer
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Neural networks-based DOA estimation of multiple stochastic narrow-band EM sources. In: 11th International Conference on Telecommunication in Modern Satellite, Cable and Broadcasting Services (TELSIKS), 2013, vol. 2. IEEE, October 16-19, 2013, pp. 526–529.
Z. Stankovic, N. Doncov, B. Milovanovic, J. Russer, I. Milovanovic, M. Agatonovic
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Real-time EM spectrum and EM interference measurement techniques. Microwave Conference (EuMC), 2013 European. IEEE, October 6-11 2013, pp. 1115–1118.
P. Russer, J. Russer, C. Hoffmann, H. H. Slim
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Efficient characterization of stochastic electromagnetic
fields using eigenvalue decomposition and principal component analysis method. XXXIth URSI General Assembly and Scientific Symposium (URSI GASS), August 17–23, 2014, pp. 1–4.
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T. Asenov, J. A. Russer, P. Russer
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Some remarks on the transmission line matrix (TLM) method and its application to transient EM fields and to EMC problems. In: Computational Electromagnetics—Retrospective and Outlook, I. Ahmed and Z. D. Chen, Eds. Heidelberg: Springer, 2014, pp. 29–56.
P. Russer, J. A. Russer
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Modeling of noisy EM field propagation using correlation
Information. IEEE Transactions on Microwave Theory and Techniques, Vol. 63. 2015, no. 1, pp. 76–89.
J. A. Russer, P. Russer
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Near-field measurement of stochastic electromagnetic fields. IEEE Electromagnetic Compatibility Magazine, Vol. 4. 2015, no. 3, pp. 79–85.
J. A. Russer, N. Uddin, A. S. Awny, A. Thiede, P. Russer
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Correlation transmission line matrix (CTLM) modeling of stochastic electromagnetic fields. In: Proceeding of: IEEE International Microwave Symposium, IMS, San Farncisco, CA, USA, May 22-27, 2016, pp. 1-4.
J. A. Russer, A. Cangellaris, P. Russer
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Multi-probe near-field measurement of stochastic noisy radiations: Perspectives for chip-package LNAprobe co-design. in Proceedings of the 46th European Microwave Conference, London, England, Oct 3-7, 2016, pp. 548-551.
S. Wane, D. Bajon, D. Lesenechal, J. A. Russer, D. Thomas, P. Russer
