Time filter

Source Type

Zurich, Switzerland

Sroka J.,EMC Testcenter Zurich | Sroka J.,Warsaw University of Technology
IEEE Transactions on Electromagnetic Compatibility | Year: 2011

Conducted radio disturbances at a power port of the equipment under test (EUT) are sensed with the artificial mains network (AMN) and transmitted via the 50-Ω coaxial system to the measurement receiver. The voltage division factor F of the two-port network between the EUT port of the AMN and the receiver input is defined by neglecting a mismatching. As a matter of course, the mismatch correction factor δM appears. It depends on all components of the path, including the AMN. This fact is ignored in Comité International Spécial des Perturbations Radioélectriques 16-4-2 document. Due to the reflection at the receiver input, whose only the extreme is usually available in the technical specification, the mismatch correction factor cannot be determined. Its estimate is built-in into the measurement uncertainty budget. Two approaches for the estimation of the mismatch correction factor by the divided and the integrated measurement path are derived. The estimations are illustrated with numerical calculations by Monte Carlo method. The distinction of the mismatch correction factor by conducted disturbances from radiated disturbances, as well as recommendation of the approach with the integrated path, constitute the essence of the paper. © 2011 IEEE.

Radiated disturbances by EMC testing are sensed with an antenna and transmitted via the 50Ω coaxial path to the receiver. The recalculation factor between the receiver signal and the measurand is defined with neglecting mismatching. As a matter of course the mismatch error appears. It is not determined but estimated and built-in into the measurement uncertainty budget. Formulas for the mismatch error by the junction antenna-receiver and with the inserted path are derived. Two approaches to estimation of the mismatch error in the bands C and D in the frequency range from 30MHz to 1GHz: the first recommended in the document CISPR 16-4-2 and the second with the Monte Carlo method are presented and illustrated with the numerical calculations. Evidently the first approach is to pessimistic and gives vastly overestimated error.

Baran J.,Czestochowa University of Technology | Sroka J.,EMC Testcenter Zurich | Sroka J.,Warsaw University of Technology
Proceedings of EMC Europe 2011 York - 10th International Symposium on Electromagnetic Compatibility | Year: 2011

Simulation of the human-metal electrostatic discharge alters slightly from one to another standard. In consequence setups with different frequency bandwidth are required for calibration of the ESD simulators. The rule of thumb valid for the trapezoidal sequence of pulses (reciprocal of the product of π and rise time) for determining the bandwidth gives the underestimated result. The authors propose another sophisticated rule of thumb. It is crossing point of the power spectral densities (PSD) of the theoretical pulses with noise level of the measurement path. According to this rule, bandwidth required in the IEC standard is wide enough but it is to narrow in the ANSI standard and in consequence in the MIL-STD. Electrostatic discharge (ESD), Frequency domain analysis, Power Spectral Density (PSD). © 2011 EMC Europe.

Baran J.,Czestochowa University of Technology | Sroka J.,EMC Testcenter Zurich | Sroka J.,Warsaw University of Technology
IEEJ Transactions on Fundamentals and Materials | Year: 2012

The paper concerns calibration of generators for simulation of the Human-Metal Electrostatic Discharge (ESD) according to the IEC 61000-4-2 standard. It is shown that analysis of the ESD pulse in the frequency domain can be an indication if omitting the frequency considerations in calibration of ESD guns is acceptable. The calibration setup consists of a target (current converter), attenuator, coaxial cable and a wideband, single shot oscilloscope. It is much easier to use only a low frequency model of such a measurement path setup than consider a high frequency model. If, however, a high frequency treatment is indispensable, then a frequency dependent transfer impedance of the measurement path and approximation of the oscilloscope frequency response with an infinite impulse response discrete time filter are adequate tools. Comparison of power spectral densities (PSD) of theoretical pulses, measured pulses as well as the measurement path noise gives a good criterion for specifying minimal bandwidth of a setup required for reliable calibration of a given ESD gun. This paper is a resume of previous papers of the authors, in which these issues were presented in details. © 2012 The Institute of Electrical Engineers of Japan.

Baran J.,Czestochowa University of Technology | Sroka J.,EMC Testcenter Zurich | Sroka J.,Warsaw University of Technology
IEEE Transactions on Electromagnetic Compatibility | Year: 2010

The paper deals with analysis of how limited bandwidth of a setup for verification of electrostatic discharge (ESD) generators affects reliability of testing. It is investigated how suppression of a high-frequency part of an ESD pulse spectrum distorts the pulse waveform and affects its standardized time domain metrics: the rise time and the peak value. Restriction of a pulse spectrum is achieved by low-pass filtering with a defined passband. The filtering models high-frequency attenuation of a measurement path, in particular that of an oscilloscope. The analysis is conducted for theoretical ESD pulses, specified by the IEC Standard, as well as for series of real noisy pulses recorded on setups with wideband 6 and 12 GHz oscilloscopes. Discrepancies of rise times and peak currents of filtered pulses with respect to an original input pulse are calculated as measures of distortion due to constraint of a pulse spectrum. It is shown that above 3 GHz, the setup circuit noise is the main factor contributing to measurement uncertainty of the metrics. © 2010 IEEE.

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