Spectral analyser measuring method

    公开(公告)号:DE19615651A1

    公开(公告)日:1996-10-24

    申请号:DE19615651

    申请日:1996-04-19

    Applicant: ADVANTEST CORP

    Abstract: The method involves converting the frequencies of an input signal using a super-imposed signal, detecting the converted output signal and sweeping through it to obtain an output signal based on frequency. Each of a number of measurement frequency ranges to be measured are swept at a low speed in sequence. Every non-measurement frequency range outside the measurement frequency range are swept at a speed higher than the low speed. The higher speed can be equal to the maximum sweep speed of the spectral analyser.

    5.
    发明专利
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    公开(公告)号:DE10015854C2

    公开(公告)日:2002-07-11

    申请号:DE10015854

    申请日:2000-03-30

    Applicant: ADVANTEST CORP

    Abstract: A power spectrum waveform is obtained by logarithmically amplifying a signal received by a frequency-sweep operation, detecting the amplified output of each frequency sweep, converting the detected output into a digital signal value in decibels, and converting this digital signal value into an antilogarithmic power value in watts for each display point within the width of the frequency sweep. Upon completion of the frequency sweep operation, the power values which have been converted into antilogarithmic values for each frequency sweep are averaged for each display point, the average power values are converted into logarithmic values, and the logarithmic values are displayed as a spectrum display.

    METHOD FOR MEASURING MUTUAL MODULATION STRAIN BY SPECTRUM ANALYZER

    公开(公告)号:JPH0980094A

    公开(公告)日:1997-03-28

    申请号:JP23166295

    申请日:1995-09-08

    Applicant: ADVANTEST CORP

    Abstract: PROBLEM TO BE SOLVED: To properly measure three-dimensional distortion of a low level. SOLUTION: The input attenuation is made 0dB (S2 ), thereby it is made large by step 10dB and the three-dimensional distortion level L3 at this time is measured (S3 ). Next, the quantity of the input attenuation is changed to δATT=1dB, a three-dimensional distortion level L3 ' and a fundamental wave level L1 are measured and at the time a change quantity of the three- dimensional distortion level δDis =L3 -L3 ' is found. If the δDis is not within δATT±ε, it will be returned to (S3 ), furthermore the attenuation of 10dB is increased, and the similar method is performed. If the δDis is within δATT±ε, the three-dimensional distortion L3 ' at this time is made input and L1 -L3 '=ΔL represents the level difference between the fundamental wave and the three- dimensional distortion.

    METHOD FOR AUTOMATICALLY SETTING PARAMETER OF SPECTRUM ANALYZER

    公开(公告)号:JPH0980092A

    公开(公告)日:1997-03-28

    申请号:JP23167895

    申请日:1995-09-08

    Applicant: ADVANTEST CORP

    Abstract: PROBLEM TO BE SOLVED: To automatically determine the pass band width(RBW) or the like of a spectrum analyzer by determining RBW of BPF on the basis of the frequency interval of a waveform to be displayed, the noise level or the like. SOLUTION: RBW of BPFs 19, 24 of a spectrum analyzer 15 is made a parameter, and RBW is determined from the frequency interval of the waveform to be displayed so as to satisfy the relation with the frequency interval of the waveform to be displayed and the noise level or the dynamic range of an input signal. In other words, a control part 31 reads the spectrum of the input signal from a buffer memory 29, detects a frequency with its maximum value and makes it a central frequency. The central frequency is stored in a parameter value storing part 36. When the central frequency is determined, the input signal is measured again so that the central frequency may be in the center of a display scope and stored in a buffer memory 29. A noise part to be measured is made an offset value, three times thereof a frequency span, and RBW of BPFs 19, 24 is determined.

    SPECTRUM ANALYZER AND ITS MEASUREMENT METHOD

    公开(公告)号:JP2000352569A

    公开(公告)日:2000-12-19

    申请号:JP2000071434

    申请日:2000-03-15

    Applicant: ADVANTEST CORP

    Abstract: PROBLEM TO BE SOLVED: To properly carry out the spectrum display of power even for an input signal with a large dynamic range by allowing the received signal to be subjected to logarithmic amplification, detection, and A/D conversion, and by performing antilogarithm conversion to the power value of the dimension of a watt for each display point in the width of frequency sweeping for obtaining an average power value. SOLUTION: An antilogarithm conversion part 31 converts a measurement value for the ith display point to the antilogarithm of the dimension of a watt by the nth sweeping. A digital value being converted by an A/D converter 17 is stored into a memory 18, and the digital value is converted by a dBm conversion part 32 for converting to the antilogarithm with dBm (decibel value) as a unit. An average value calculation part 34 adds the antilogarithm being converted by the antilogarithm conversion part 31 to the ith antilogarithm addition value up to the previous sweeping in an addition value memory 33, and at the same time divides the addition value of the antilogarithm up to nth time for obtaining an average value. A logarithm conversion part 35 calculates the logarithm of the average value for obtaining the display data of a display point (i), for storing into a logarithmic value memory 37, and at the same time for displaying at the display point (i) of a display 24.

    MEASURING METHOD BY SPECTRUM ANALYZER

    公开(公告)号:JPH0980100A

    公开(公告)日:1997-03-28

    申请号:JP23169195

    申请日:1995-09-08

    Applicant: ADVANTEST CORP

    Abstract: PROBLEM TO BE SOLVED: To simply show time progress of noise level change by displaying the spectrum waveform of an input signal on one half part of a display screen and displaying noise on the other half part in a time domain. SOLUTION: A carrier frequency is positioned in the center of the left half of a display screen, and frequencies upward and downward separated by an offset value fof from the carrier frequency on both ends, and each spectrum therebetween is displayed. In other words, a spectrum waveform (frequency region) is displayed. In addition, the level of noise of a frequency fN upward separated by the offset value fof from the carrier frequency is displayed in time domain on the right half part of the display screen. In spectrum display for the frequency region of the left half part, frequency sweep is performed at least between fc ±Fof in regard to an input signal, necessary parts are taken out from data taken in a backup memory and are displayed. Taken-in display of the data for the left part display and the other taken-in display of the data for the right part display are performed alternately.

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