PIER B
 
Progress In Electromagnetics Research B
ISSN: 1937-6472
Home | Search | Notification | Authors | Submission | PIERS Home | EM Academy
Home > Vol. 29 > pp. 175-190

A PROPOSED METHOD FOR QUANTIFYING UNCERTAINTY IN RF IMMUNITY TESTING DUE TO EUT PRESENCE

By E. Paez, C. Tremola, and M. A. Azpurua

Full Article PDF (550 KB)

Abstract:
Throughout the performance of a RF immunity test according IEC 61000-4-3 there are several factors that should be taken into account to ensure the quality and to estimate the uncertainty associated to the results. One phenomenon that should be considered to calculate uncertainty is the disturbing effect produced by the EUT over the electric field generated within the calibrated uniform field area; nevertheless the mentioned effect is not easily quantifiable because the measuring process using additional antennas or field probes inside the semianechoic chamber could also alter the electric field distribution. An experimental method for quantifying the mentioned uncertainty contribution is presented. The method is based upon the fact that antenna-EUT coupling and reflection effects could be measured through changes in the input impedance of the field generation antenna. A validation procedure for the proposed method is also described. Hence, a relationship between the reflection coefficient at the antenna input port and the electric field strength is derived. The uncertainty contribution is calculated through the maximum relative change in the E-field intensity magnitude for the frequency range of 80-1000 MHz, considering the worst case for several EUT positions.

Citation:
E. Paez, C. Tremola, and M. A. Azpurua, "A Proposed Method for Quantifying Uncertainty in RF Immunity Testing Due to Eut Presence," Progress In Electromagnetics Research B, Vol. 29, 175-190, 2011.
doi:10.2528/PIERB11020802

References:
1. Williams, T., EMC for Product Designers, 4th Ed., 164-184, Newness, Oxford, 2007.
doi:10.1016/B978-075068170-4/50007-4

2. Williams, T. and S. Baker, "Uncertainties of immunity measurements," Main Report of the DTI-NMSPU Project R2.2b1, Schaffiner EMC Systems and Elmac Services, 2002.

3. González, J. and J. Romeu, "Measurement of radiation efficiency and quality factor of fractal antennas: The wheeler cap method," FractalComs, Information Society Technologies Programme, 2002.

4. Smith, G., "An analysis of the Wheeler method for measuring the radiating efficiency of antennas," IEEE Transactions on Antennas and Propagation, Vol. 25, No. 4, 552-556, 1977.
doi:10.1109/TAP.1977.1141615

5., The Expression of Uncertainty in EMC Testing, 1st Ed., UKAS Publication LAB 34, 2002.

6., EMC Measurement Uncertainty: A Handy Guide, Schaffner EMC Systems, 2002.

7. Balanis, C. A., Antenna Theory: Analysis and Design, 3rd Ed., John Wiley & Sons, 2005.

8. Betta, G., D. Capriglione, C. F. M. Carobbi, and M. D. Migliore, "Calibration of antenna for EMI measurements in compact semi-anechoic rooms," 16th IMEKO TC4 Symposium, 2008.

9. Trzaska, H., Electromagnetic Field Measurements in the Near Field, 66-68, Noble Publishing Corporation Atlanta, 2000, ISBN: 10884932-10-X.

10. IEC 61000-4-3, "Testing and measurement techniques --- Radiated, radio-frequency, electromagnetic field immunity test," Electromagnetic Compatibility (EMC), Part 4-3, Edition 3.2, Apr. 2010.

11. Przesmycki, R., L. Nowosielski, M. Wnuk, and R. Kubacki, "The expanded uncertainty for radio frequency immunity testing," PIERS Online, Vol. 6, No. 1, 81-85, 2010.
doi:10.2529/PIERS090907022607

12. Dalke, R. A., A numerical method for the analysis of coupling to thin wire structures, Symposium of Electromagnetic Compatibility, Lakewood, 1988.

13. Pozar, D., Microwave Engineering, 2nd Ed., 87-90, Hohn Wiley & Sons, Amherst, 1998.

14. Montrose, M. and E. Nakaguchi, Testing for EMC Compliance, Approaches and Techniques, 228-234, IEEE Press, Danvers, 2004.

15., "Uncertainties in the measurement of mobile radio equipment characteristics," ETSI Technical Report, Part 2, ETSI TR 100 028-2, V1.4.1, December 2001.


© Copyright 2010 EMW Publishing. All Rights Reserved