- Volume 11 Issue 4
The application of time-domain methods in emission measurement instruments allows for a reduction in scan time by several orders of magnitude and for new evaluation methods to be realized such as the real-time spectrogram to characterize transient emissions. In this paper two novel systems for time-domain EMI measurements above 1 GHz are presented. The first system combines ultra-fast analog-to-digital-conversion and real-time digital signal processing on a field-programmable-gate-array (FPGA) with ultra-broadband multi-stage down-conversion to enable measurements in the range from 10 Hz to 26 GHz with high sensitivity and full-compliance with the requirements of CISPR 16-1-1. The required IF bandwidths were added to allow for measurements according to MIL-461F and DO-160F. The second system realizes a system of time-interleaved analog-to-digital converters (ADCs) and has an upper bandwidth limit of 4 GHz. With the implementation of an automatic mismatch calibration, the system fulfills CISPR 16-1-1 dynamic range requirements. Measurements of the radiated emissions of electronic consumer devices and household appliances like the non-stationary emissions of a microwave oven are presented. A measurement of a personal computer's conducted emissions on a power supply line according to DO-160F is given.
Electromagnetic Compatibility;Electromagnetic Interference;Time-Domain Measurements
- C. R. Barhydt, "Radio noise meter and its application," General Electric Rev., vol. 36. pp. 201-205, 1933.
- C. Keller, K. Feser, "A new method of emission measurement," 2002 IEEE International Symposium on Electromagnetic Compatibility, Minneapolis, USA, pp. 599-604, 2002.
- F. Krug, P. Russer, "Ultra-Fast broadband EMI Measurement in time-domain using FFT and Periodigram," 2002 IEEE International Symposium on Electromagnetical Compatibility, Minneapolis, USA, pp. 587-582, 2002.
- S. Braun, T. Donauer, and P. Russer, "A real-time time-domain EMI measurement system for full-compliance measurements according to CISPR 16-1-1," IEEE Transactions on Electromagnetic Compatibility, vol. 50 no. 2, pp. 259-267, May 2008. https://doi.org/10.1109/TEMC.2008.918980
- C. Hoffmann, P. Russer, "A real-time low-noise ultra- broadband time-domain EMI measurement system up to 18 GHz," IEEE Transactions on Electromagnetic Compatibility, vol. 53, 2011.
- MIL-STD-461F: "Requirements for the control of electromagnetic interference characteristics of subsystems and equipment," Department of Defense Interface Standard, 2010.
- DO-160F: "Environmental conditions and test procedure for airborne equipment," RTCA, Incorporated, 2007.
- CISPR 16-1-1, Ed. 3.1 Am. 1, "Specification for radio disturbance and immunity measuring apparatus and methods Part 1-1: Radio disturbance and immunity measuring apparatus - Measuring apparatus," International Electrotechnical Commission, 2010.
- H. H. Slim, P. Russer, "Digital automatic calibration method for a time-interleaved ADCs system used in time-domain EMI measurement receiver," IEEE Symposium on Electromagnetic Compatibility 2011, Long Beach, USA, pp. 476-479, 2011.
- J. Allen, "Short term spectral analysis, synthesis, and modification by discrete fourier transform," IEEE Transactions on Acoustics, Speech and Signal Processing, vol. 25, pp. 235-238, 1977. https://doi.org/10.1109/TASSP.1977.1162950
- W. B. Davenport, D. L. Root, An Introduction to the Theory of Random Signals and Noise, John Wiley & Son, 1987.
- W. C. Black, D. A. Hodges, "Time interleaved converter arrays," IEEE Journal of Solid-State Circuits, vol. 15, no. 6, pp. 1022-1029, Dec. 1980. https://doi.org/10.1109/JSSC.1980.1051512
- N. Kurosawa, H. Kobayashi, K. Maruyama, H. Sugawara, and K. Kobayashi, "Explicit analysis of channel mismatch effects in time-interleaved ADC systems," IEEE Transactions on Circuits and Systems I: Fundamental Theory and Applications, vol. 48, no. 3, pp. 261-271, Mar. 2001. https://doi.org/10.1109/81.915383