WO2003016927A1 - Procede et dispositif pour determiner la courbe spectrale de signaux electromagnetiques a l'interieur d'une gamme de frequences - Google Patents

Procede et dispositif pour determiner la courbe spectrale de signaux electromagnetiques a l'interieur d'une gamme de frequences Download PDF

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Publication number
WO2003016927A1
WO2003016927A1 PCT/DE2002/002609 DE0202609W WO03016927A1 WO 2003016927 A1 WO2003016927 A1 WO 2003016927A1 DE 0202609 W DE0202609 W DE 0202609W WO 03016927 A1 WO03016927 A1 WO 03016927A1
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WIPO (PCT)
Prior art keywords
frequency
signal
frequency range
spectral
course
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Application number
PCT/DE2002/002609
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German (de)
English (en)
Inventor
Jean-Claude Nickel
Original Assignee
Siemens Aktiengesellschaft
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Publication date
Application filed by Siemens Aktiengesellschaft filed Critical Siemens Aktiengesellschaft
Publication of WO2003016927A1 publication Critical patent/WO2003016927A1/fr

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R23/00—Arrangements for measuring frequencies; Arrangements for analysing frequency spectra
    • G01R23/16—Spectrum analysis; Fourier analysis
    • G01R23/165—Spectrum analysis; Fourier analysis using filters

Definitions

  • the invention relates to a method and a device for determining the spectral profile of electromagnetic signals within a predetermined frequency range.
  • Electromagnetic signals are analyzed when measuring the emission of electromagnetic interference (EMC).
  • EMC electromagnetic interference
  • devices are examined with regard to their EMC by analyzing the electromagnetic signals generated and emitted by the device.
  • the emitted electromagnetic waves are referred to as interference signals.
  • the spectral intensity or the spectrum of the interference signals is determined, i. H. the intensity of the interference signals as a function of frequency.
  • a specified frequency range e.g. B. between 20 MHz and 1 GHz.
  • EMC measurements are usually carried out using an antenna that receives the electromagnetic waves emitted by the device.
  • the output signal of the antenna is fed to a test receiver.
  • a measurement receiver enables the spectrum of the interference signals to be measured in small frequency steps in accordance with associated small frequency intervals of typically 10 kHz.
  • the exact functioning of a measurement receiver is described below in connection with FIG. 1.
  • the width of the frequency intervals is called the intermediate frequency or IF bandwidth of the test receiver. It represents the measurement bandwidth, i.e. the frequency range that is recorded by the measurement receiver at a specified point in time. Each frequency interval must be measured for a certain time.
  • the duration T of an EMC measurement thus results from
  • T T mess * (f max -f min) / frequency step size
  • T mess denotes the period of time with which a single frequency interval is measured
  • f max the upper limit of the frequency range to be measured
  • f mm the lower limit of the frequency range to be measured
  • the frequency step size m is usually selected equal to half the IF bandwidth, d. H.
  • Frequency step size ZF-BB / 2
  • Typical values for T mess are 1 to 100 ms.
  • Typical values for the IF bandwidth are 9 kHz and 120 kHz.
  • the total measuring time is approximately one hour. If three devices are measured in two operating states each and in both the horizontal and vertical polarization direction (together 12 measurements) and additionally a zero measurement (checking the measuring station for external disturbances) is carried out (a total of 13 measurements), whereby both the peak value and If the mean value is measured in the frequency interval, the result is 37h 45 'for the measurement.
  • the object of the invention is to further improve the known method.
  • the predetermined frequency range is divided into a plurality of frequency intervals.
  • the specified frequency range may range from 20 MHz to 1 GHz. It is divided into frequency intervals of 1 MHz, for example.
  • the electromagnetic signal is filtered with regard to the frequencies falling in the frequency interval.
  • a commercially available measuring receiver can be used, for example, whose IF bandwidth can determine the width of the frequency interval at 1 MHz.
  • the time course of the filtered signal is scanned, for example with a conventional single-shot storage oscilloscope.
  • the sampled temporal course is transformed into the frequency space in order to obtain the spectral course of the electromagnetic radiation of the device within the frequency interval. For this purpose, z. B.
  • the individual frequency intervals can be successively z. B. with the help of a commercially available measuring receiver.
  • the spectral course of the individual frequency intervals is brought together in order to obtain the spectral course within the entire predetermined frequency range.
  • the EMC measurement is therefore carried out in rough steps with a large measurement bandwidth, for example 1 MHz.
  • the frequency range is further subdivided using Fast Fourier Transformation (FFT). This means that several frequency points are measured practically simultaneously, which drastically reduces the measuring time.
  • FFT Fast Fourier Transformation
  • the three devices mentioned by way of example at the beginning are measured in two states and both in horizontal and vertical polarization direction (altogether 12 measurements) and additionally a zero measurement is carried out (ms total 13 measurements), both the peak value and the mean value being determined, instead of 37h 45 'for the measurement from 20 MHz to 1 GHz with the method according to the invention, there is only a measurement time of about 2 hours.
  • EMC measurements are drastically shortened compared to the conventional method.
  • the measuring time for an EMC measurement can theoretically be reduced by two orders of magnitude with the method according to the invention if, for example, B. with an IF bandwidth of 1 MHz instead of 10 kHz.
  • the method according to the invention enables an extensive analysis of the measurement signal.
  • the temporal course of a disturbance signal and the temporal change in a spectrum can be displayed in a three-dimensional representation.
  • a commercially available measurement receiver can be used to transform the recorded electromagnetic signal to a predetermined frequency, for example to a usual intermediate frequency of 10.7 MHz. Then, according to the sampling theorem (see below), a sampling rate of approximately 25 MS / s is sufficient.
  • the sampling rate can be reduced even further, namely to two to three times the bandwidth of the respective frequency interval, whereby the signal can still be clearly reconstructed (see below).
  • a sampling rate of 2.5 MS / s is sufficient.
  • the associated data rate at one byte per measuring point is 2.5 Mbytes per second, which is easy to use.
  • the method according to the invention makes it possible for the spectral course to be recorded within a predetermined frequency interval for a plurality of time intervals which are contiguously adjacent to one another. If, for example, a single-shot storage oscilloscope with a storage depth of 120,000 measuring points is used, a time interval of
  • FIG. 1 shows the schematic structure of a measurement receiver in the form of a block diagram and further components of the measurement structure; and FIG. 2 shows some schematic representations to explain the sampling theorem or some schematic representations of signals reconstructed from a sampling.
  • Fig. 1 shows the basic structure for recording and evaluating the data of an EMC measurement.
  • An antenna for recording the interference signals is connected to the input of a test receiver.
  • the test receiver has high-frequency (HF) attenuation, which attenuates peak voltages.
  • the signals are then subjected to a preselection in the form of a bandpass filter. After the preselection, signals that are too weak can optionally be amplified in a preamplifier. Then the signals are mixed in a mixer with the sig- mixed a frequency tunable local oscillator.
  • HF high-frequency
  • the frequencies fl +/- f2, fl +/- 2 * f2, 2 * fl +/- f2, etc. are obtained at the output of the mixer a frequency fl of approximately 100 MHz at the input mixed with a frequency f2 of the local oscillator of approximately 89.3 MHz, after the mixer there is, among other things, a component at a frequency of fl - f2, that is to say at approximately 10.7 MHz , This component can be selected in a bandpass filter, the intermediate frequency filter (IF filter).
  • IF filter the intermediate frequency filter
  • the input signal was transformed from 100 MHz to 10.7 MHz.
  • the signal on the filtered intermediate frequency is amplified and sent to the outside via an intermediate frequency output (IF output).
  • IF output intermediate frequency output
  • a commercially available measuring receiver generally also has a display device for the signals detected at the intermediate frequency.
  • the signals on the intermediate frequency are first attenuated, then evaluated with a suitable detector, then logarithmic and displayed on a screen. However, these components are not used. The device is only used up to the IF output.
  • the IF output signal is sampled with a single-shot storage oscilloscope.
  • the oscilloscope does not perform averaging or summation, so the signal is recorded without any distortion.
  • Fig. 2A the level p of various reconstructed signals is plotted against the frequency f.
  • the sampling rate is designated with fab.
  • the spectrum of the sought signal 10 that is to say the level strength as a function of the frequency or the spectral profile, extends from the frequency 0 to approximately half the sampling rate fab.
  • the sought signal 10 is reconstructed from the sampled values recorded with the frequency fab, a large number of other possible solutions for the reconstructed signal result in addition to the signal 10 itself.
  • These are symmetrically mirrored around the sampling rate fab (12, 14), around twice the sampling rate 2 * fab (16, 18), around three times the sampling rate 3 * fab (not shown), etc.
  • FIG. 2B illustrates the case in which the signal to be reconstructed contains frequencies that are higher than half the sampling rate fab, or the case in which the sampling rate is not more than twice as high as the highest frequency present in the signal. There is then an overlap 20 between the signal 10 to be reconstructed and its reflection 12 at the sampling rate fab. For the frequencies in the overlap region 20 it can no longer be clearly determined whether they belong to the reconstructed signal 10 or to its reflection 12. A clear reconstruction of the signal is no longer possible.
  • FIG. 2C illustrates the case in which a narrow-band high-frequency signal 22 is sampled at a frequency fab which is approximately four times as low as the high-frequency signal 22.
  • the reconstruction results in addition to the sought-after signal 22 in such a case - gave 24 of the searched signal, shifted by a multiple of the sampling rate n * fab, as well as the same reconstructed levels at corresponding negative frequencies. Due to the Narrow band of the high-frequency signal 22 there is no overlap between the various possible reconstructions of the signal. The signal can thus be clearly reconstructed in all details, provided its essential carrier frequency is known.
  • the prerequisite is to limit the bandwidth of the signal to be reconstructed to a maximum of half the sampling rate and to choose a suitable ratio between the IF frequency and the sampling rate.
  • the IF bandwidth is 1 MHz in the preferred exemplary embodiment, a sampling rate of 2.5 MHz is therefore sufficient for the reconstruction of the signal.
  • the oscilloscope therefore taps the IF output at a sampling rate of 2.5 MHz.
  • the IF bandwidth must then be limited to a maximum of 1 MHz.
  • the data captured by the storage oscilloscope are e.g. For example, supplied to a computer via an IEC bus and evaluated by it. The data is processed further and the results are displayed on the computer.
  • the signal measured in the time domain is transformed into the frequency domain using Fourier transformation. This transformation can be carried out particularly quickly if the number of values to be transformed is 2 m, e.g. B. 256, 512, 1024, 2048, etc., amounts. Then the so-called Fast-Fou ⁇ er transformation algorithm (FFT) can be used.
  • FFT Fast-Fou ⁇ er transformation algorithm
  • 2 ⁇ n points are extracted from the measuring points read out by the oscilloscope and transformed into the frequency range by means of FFT.
  • several frequency curves are formed at a time period that is contiguous.
  • the components around 700 kHz +/- 500 kHz are extracted from the reconstructed spectra.
  • This corresponds to a bandwidth of 1 MHz, ie exactly the IF bandwidth in the preferred exemplary embodiment.
  • the IF bandwidth corresponds to e.g. B. twice the step size when scanning the entire frequency range of the interference signal.
  • Other step sizes are also conceivable, but IF bandwidth and sampling rate must always be coordinated.
  • a step size that exactly corresponds to the IF bandwidth can be used. should be selected because possible measurement errors due to the frequency response of the IF filter can be eliminated by calculation.
  • the achievable frequency resolution results from the sampling rate divided by the number of points that are used for the FFT. At a sampling rate of 2.5 MHz and 2048
  • Points for the FFT result in a very good frequency resolution of around 1 kHz. A frequency resolution of 1 kHz would lead to an unacceptably long measurement duration with conventional methods.
  • a suitable choice of the number of points used for the FFT and a suitable choice of a mathematical filter function to compensate for distortions can be realized.
  • the invention can generally be used to analyze electromagnetic signals, that is, not only signals emitted by devices that are picked up by an antenna, but z. B. disturbances on supply or signal lines can be analyzed with the aid of the invention.

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  • Physics & Mathematics (AREA)
  • Mathematical Physics (AREA)
  • General Physics & Mathematics (AREA)
  • Monitoring And Testing Of Transmission In General (AREA)

Abstract

Selon l'invention, la mesure d'un rayonnement, en ce qui concerne la compatibilité électromagnétique, est exécutée, selon des étapes grossières, avec une grande largeur de bande de mesure de 1 MHz. Le signal faisant l'objet de la mesure en ce qui concerne la compatibilité électromagnétique est filtré par ladite largeur de bande de mesure. Le signal filtré est ensuite échantillonné temporellement. L'autre subdivision de la gamme de fréquences se fait à l'aide d'une transformée de Fourier rapide. Ainsi, plusieurs points de fréquence sont mesurés pratiquement simultanément, ce qui réduit nettement le temps de mesure.
PCT/DE2002/002609 2001-07-26 2002-07-17 Procede et dispositif pour determiner la courbe spectrale de signaux electromagnetiques a l'interieur d'une gamme de frequences WO2003016927A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE10136626.4 2001-07-26
DE2001136626 DE10136626A1 (de) 2001-07-26 2001-07-26 Verfahren und Vorrichtung zum Bestimmen des spektralen Verlaufs von elektromagnetischen Signalen innerhalb eines vorgegebenen Frequenzbereichs

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WO2003016927A1 true WO2003016927A1 (fr) 2003-02-27

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Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10315372B4 (de) * 2003-04-03 2005-03-31 Technische Universität München Verfahren und Vorrichtung zum Bereitstellen eines Messsignals und Vorrichtung zur Erfassung einer elektromagnetischen Störung
DE102006062995B3 (de) 2006-02-06 2023-06-07 GAUSS INSTRUMENTS International GmbH Verfahren und Anordnung zur Messung von Störemissionen in Realzeit
DE102006005595B8 (de) * 2006-02-06 2015-03-12 GAUSS INSTRUMENTS Vertriebs GmbH Vorrichtung und Verfahren zur Messung von Störemissionen in Echtzeit
CN103323668B (zh) * 2013-06-18 2015-06-24 北京空间飞行器总体设计部 航天器电源控制器母线电磁兼容性传导发射频域测试方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4665494A (en) * 1982-12-17 1987-05-12 Victor Company Of Japan, Limited Spectrum display device for audio signals
EP0244071A1 (fr) * 1986-04-23 1987-11-04 Stc Plc Récepteur pour l'analyse spectrale de fréquences radio
US4896102A (en) * 1988-06-13 1990-01-23 Scientific-Atlanta, Inc. Spectrum analyzer
US5629703A (en) * 1995-08-09 1997-05-13 Tektronix, Inc. Method for reducing harmonic distortion in an analog-to-digital converter system
WO1998059252A1 (fr) * 1997-06-25 1998-12-30 Ifr Limited Analyseur de spectre

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2237649B (en) * 1989-09-08 1994-02-09 Gale P Michael Weighted channelized receiver
DE4123983C2 (de) * 1990-09-11 1997-09-18 Head Acoustics Gmbh Iteratives Verfahren zur hochauflösenden Spektralanalyse und Extrapolation von Signalen
FR2695730B1 (fr) * 1992-09-08 1995-11-17 Aerometrics Inc Methode et appareil pour traiter un signal numerique ameliore utilisant une transformee de fourier.

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4665494A (en) * 1982-12-17 1987-05-12 Victor Company Of Japan, Limited Spectrum display device for audio signals
EP0244071A1 (fr) * 1986-04-23 1987-11-04 Stc Plc Récepteur pour l'analyse spectrale de fréquences radio
US4896102A (en) * 1988-06-13 1990-01-23 Scientific-Atlanta, Inc. Spectrum analyzer
US5629703A (en) * 1995-08-09 1997-05-13 Tektronix, Inc. Method for reducing harmonic distortion in an analog-to-digital converter system
WO1998059252A1 (fr) * 1997-06-25 1998-12-30 Ifr Limited Analyseur de spectre

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