GB2249842A - Measuring settling characteristics of devices - Google Patents
Measuring settling characteristics of devices Download PDFInfo
- Publication number
- GB2249842A GB2249842A GB9121846A GB9121846A GB2249842A GB 2249842 A GB2249842 A GB 2249842A GB 9121846 A GB9121846 A GB 9121846A GB 9121846 A GB9121846 A GB 9121846A GB 2249842 A GB2249842 A GB 2249842A
- Authority
- GB
- United Kingdom
- Prior art keywords
- fourier transform
- data
- measured
- measuring
- measured data
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
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
Landscapes
- Physics & Mathematics (AREA)
- Mathematical Physics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Resistance Or Impedance (AREA)
- Testing Electric Properties And Detecting Electric Faults (AREA)
Abstract
A method for measuring a settling characteristic of a device (101) comprises measuring (106) an output signal (103) of the DUT (101) and digitizing (107) to obtain measured data; determining an amplitude (Ad) and a do offset (Od) of the measured data; effecting (108) a Fourier transform to obtain a first set of transform data; measuring a flat top reference step pulse signal whose amplitude (Ar) and do offset (Or) are equal to those of the measured data and effecting a Fourier transform; determining a transfer function of the measuring system on the basis of a Fourier transform of an ideal step pulse signal and the Fourier transform of the reference measured data; determining a second set of measured signal transform data using the first set of transform data and the transfer function of the measuring system; and subjecting the second set of transform data to inverse Fourier transformation and on the basis thereof determining the settling characteristic of the DUT. <IMAGE>
Description
2 24 9') 42 METHOD AND APPARATUS FOR MEASURING A SETTLING CHARACTERISTIC
Field of the Invention
The present invention relates to methods and apparatuses for measuring a settling characteristic with high accuracy.
Backcrround of the Invention An important requirement in evaluating dynamic characteristics of a device under test (DUT), such as an amplifier or the like, is the evaluation of an output- settling characteristic, such a settling time of the DUT. Much effort has hitherto been exerted, in connection with systems for accurately measuring an output-settling characteristic of a DUT, in attempting to eliminate adverse effects of the measuring system, including a sampler of the measuring system, on the measurement accuracy.
In Japanese Patent Application No. 140614/1987, a reference step pulse having at least one flat wave height level is applied to a measuring system and a transfer function of the measuring system is determined by using reference measured data thereby obtained. The DUT is then electrically connected to the measuring system and a settling characteristic of the DUT is determined by using the transfer function and measured data obtained from the DUT.
That is, if a Fourier transform of data x(t) obtained by sampling a reference step pulse is represented I, 488048/HPF183 - 2 - PATENT by X(s), a Fourier transform of an ideal step pulse signal is represented by A(s) and the transfer function of the measuring system is represented by G(s), the following formula holds:
G(s) = X(s) / A(s).
In addition, if data y(t) is obtained by sampling an output signal b(t) of the DUT and the Fourier transform of samples y(t) is represented by Y(s), the Fourier transform of b(t) is given by the formula:
B(s) = Y(s) / G(s) Accordingly, B(s) may also be obtained from the f ormula:
B (s) = Y (s) x A (s) / X (s) and if this data (i.e., the right hand side) is subjected to an inverse Fourier transform to determine b(t), it is possible to measure a settling characteristic of the DUT.
This method of measuring a settling characteristic is effective in a case where the measuring system is linear. However, in a case where the measuring system is nonlinear, measurement errors occur depending on the amplitude, the magnitude of an offset, polarity, and so on, of the measured signal y(t).
Accordingly, a primary object of the present invention is to provide a method and apparatus for measuring a settling characteristic with high accuracy.
SummaKy of the Invention The present invention encompasses methods and apparatuses for measuring a settling characteristic of a device under test (DUT). A method in accordance with the present invention comprises the steps of measuring an output signal of the DUT and digitizing the same so as to obtain measured data; determining at least one of an amplitude and a dc offset of the said measured data; effecting a Fourier transform of the measured data to obtain a first set of measured signal Fourier transform data; measuring a reference step pulse signal whose 1 488048/HPF183 - 3 PATENT is amplitude and dc offset are equal to those of the measured data and whose at least one wave height is flat so as to obtain reference measured data, and effecting a Fourier transform of the said reference measured data; determining a transfer function of the measuring system on the basis of both a Fourier transform of an ideal step pulse signal and the Fourier transform of the reference measured data; determining a second set of measured signal Fourier transform data on the basis of both the first set of measured signal Fourier transform data and the transfer function of the measuring system; and subjecting the second set of measured signal Fourier transform data to inverse Fourier transformation and on the basis thereof determining a settling characteristic of the DUT.
In one embodiment of the present invention the first set of measured signal Fourier transform data and the Fourier transform of the reference measured data are effected with respect to those portions of the measured signal and the reference step pulse signal with the same polarity.
In accordance with a preferred embodiment of the present invention, an output of a DUT is first connected to a measuring system and measured data y(t) is obtained by sampling an output signal b(t) of the DUT, an amplitude and a dc offset of the measured data are determined, and a Fourier transform of the measured data is effected.
A reference step pulse signal having at least one flat wave height level and having an amplitude and offset set to be identical with the amplitude and offset of the output signal of the DUT is then applied to the measuring system.
A transfer function of the measuring system (G(s)) is then determined on the basis of both a Fourier transform (X(s)) of the reference measured data and a Fourier transform (A(s)) of an ideal step pulse signal.
Finally a Fourier transform (B(s)) of the output signal of the DUT is determined on the basis of both the 488048/HPF183 - 4 - PATENT transfer function (G(s)) and the Fourier transform of the measured data (Y(s)). The Fourier transform (B(s)) thus obtained is subjected to inverse Fourier transformation so as to obtain a settling characteristic of the device under 5 test.
As a result, it is possible to eliminate measurement errors due to the amplitude of the signal to be measured and the magnitude of an offset thereof, so that the settling characteristic can be measured with high accuracy. Moreover, measurement errors due to a difference in polarity can be eliminated by performing the Fourier transform of the measured data and the Fourier transform of the reference measured data on those portions of the measured signal and the reference step pulse signal having 15 the same polarity.
A measuring system in accordance with the present invention comprises means for carrying out each of the foregoing steps.
Brief Description of the Drawinqs
Figure 1 is a block diagram of a preferred embodiment of an apparatus for measuring a settling characteristic in accordance with the present invention.
Figure 2 is a diagram illustrating a measuring operation in the apparatus shown in Figure 1.
Figure 3 is an explanatory diagram illustrating a frequency data interpolation operation.
Detailed Description of a Preferred Embodiment
Figure 1 illustrates an apparatus for measuring a settling characteristic in accordance with the present invention.
A relay 103 is first set in a closed (on) state, and a DUT 101 is connected to a measuring system 110 comprising a transmission line 105, a sampler 106 (preferably a HP94805-61062 sampler, available from Hewlett-Packard Company (HP)), a digitizer 107 (preferably -1 J 488048/HPF183 PATENT a HP94802-61062 digitizer, available from HP) and an arithmetic unit 108. By conducting a measurement, an amplitude Ad and a dc offset Od (see Fig. 2) of an output from the DUT 101 are determined on the basis of the measured data.
A Fourier transform of the measured data is then determined by the arithmetic unit 108.
Next, a relay 104 is turned on (i.e., closed), relay 103 is turned off (opened) and a reference step pulse signal that has at least one wave height level that is flat is output by a flat pulse generator (FPG) 102 (preferably a HP94815-61080 FPG, available from HP) and measured by the measuring system 110. At this juncture, it is necessary for an amplitude Ar and an offset or of the reference step pulse to be set equal to the Ad and Od of the measured signal, respectively.
A Fourier transform is then effected by the arithmetic unit 108 on the basis of the reference measured data obtained.
Next, a transfer function of the measuring system is determined on the basis of the Fourier transform of the reference measured data and the Fourier transform of an ideal step pulse signal.
Finally, Fourier transform data is determined on the basis of the transfer function of the measuring system and the Fourier transform of the measured data (the data from the DUT), and that Fourier transform is subjected to inverse Fourier transformation so as to obtain an output settling characteristic of the DUT.
In this case, if a Fourier transform of a Tl portion of the reference step pulse (see Fig. 2) is used in determining a settling characteristic following a rise of the signal to be measured, and a Fourier transform of a Tf portion of the reference step pulse is used in determining a settling characteristic following a fall of the signal to be measured, it is possible to eliminate a measurement error due to a difference in polarity. It should be noted 488048/HPF183 - 6 - PATENT that the wave height level of the portion of the reference step pulse which is used for the Fourier transform must be flat.
In a case where the period of the output signal y(t) of the DUT differs from the period of the output signal of the FPG, there will be a difference between the frequency components of the transfer function of the measuring system G(f) and the frequency components of the Fourier transform Y(f) of the measured data. In this case, it would suffice if the period of the output signal of the FPG were made to conform with that of the output signal of the DUT. As an alternative, as shown in Figure 3, it would also suffice if an interpolation were conducted through a proportional calculation with respect to the frequency components in either one of the frequency domains, so as to determine the magnitude of the frequency components at a frequencies corresponding to the frequencies of the frequency components in the other domain.
In Figure 3, frequencies F1, F2, F3,... of the frequency components of transfer function G(f) differ from the frequencies of frequency components fl, f2, f3,... of the Fourier transform Y(f) of the measured data. Accordingly, if values gl, g2, g3 of G(f) at frequencies corresponding to fl, f2, f3,... are determined by an interpolation calculation with respect to adjacent ones of the frequency components, it is possible to conduct the calculation of B(f) = Y(f) / G(f).
many modifications and variations of the preferred embodiment just described are within the true scope of the present invention. The following claims are intended to encompass all such embodiments.
d 488048/HPFIS3
Claims (3)
1. A method for measuring a settling characteristic of a device under test (DUT) with a 5 measuring system, comprising the steps of:
(a) measuring an output signal of the DUT and digitizing the same so as to obtain measured data; (b) determining at least one of an amplitude and a dc offset of the said measured data; (c) effecting a Fourier transform of the measured data to obtain a first set of measured signal Fourier transform data; (d) measuring a reference step pulse signal whose amplitude and dc offset are equal to those of the measured data and whose at least one wave height is flat so as to obtain reference measured data, and effecting a Fourier transform of the said reference measured data; (e) determining a transfer function of the measuring system on the basis of both a Fourier transform of an ideal step pulse signal and the Fourier transform of the reference measured data; (f) determining a second set of measured signal Fourier transform data on the basis of both the first set of measured signal Fourier transform data and the transfer function of the measuring system; and (g) subjecting the second set of measured signal Fourier transform data to inverse Fourier transformation and on the basis thereof determining a settling characteristic of the DUT.
PATENT
2. A method for measuring a settling characteristic as recited in claim 1, wherein the first set of measured signal Fourier transform data and the Fourier transform of thb reference 'measured data are effected with respect to those portions of the measured signal and the reference step pulse signal with the same polarity.
488048/HPF183 - 8 - PATENT
3. A measuring system for measuring a settling characteristic of a device under test (DUT), comprising:
(a) means for measuring an output signal of the DUT and digitizing the same so as to obtain measured data; (b) means for determining at least one of an amplitude and a dc offset of the said measured data; (c) means for effecting a Fourier transform of the measured data to obtain a first set of measured signal Fourier transform data; (d) means for measuring a reference step pulse signal whose amplitude and dc offset are equal to those of the measured data and whose at least one wave height is flat so as to obtain reference measured data, and means for effecting a Fourier transform of the said reference measured data; (e) means for determining a transfer function of the measuring system on the basis of both a Fourier transform of an ideal step pulse signal and the Fourier transform of the reference measured data; (f) means for determining a second set of measured signal Fourier transform data on the basis of both the first set of measured signal Fourier transform data and the transfer function of the measuring system; and (g) means for subjecting the second set of measured signal Fourier transform data to inverse Fourier transformation and on the basis thereof determining a settling characteristic of the DUT.
1 I- X i i
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2295095A JP3045759B2 (en) | 1990-10-31 | 1990-10-31 | Settling characteristics measurement method |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB9121846D0 GB9121846D0 (en) | 1991-11-27 |
| GB2249842A true GB2249842A (en) | 1992-05-20 |
| GB2249842B GB2249842B (en) | 1994-12-14 |
Family
ID=17816240
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9121846A Expired - Fee Related GB2249842B (en) | 1990-10-31 | 1991-10-15 | Method and apparatus for measuring a settling characteristic |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP3045759B2 (en) |
| DE (1) | DE4133619C2 (en) |
| GB (1) | GB2249842B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4229770A1 (en) * | 1992-09-05 | 1994-03-10 | Asea Brown Boveri | Measuring transient repetitive voltage of circuit using current injection - feeding current pulse to comparison resistance for calibration and measuring voltage drop, feeding pulse into circuit, measuring voltage drop and integrating to determine time delay, slope and peak amplitude |
| US5656932A (en) * | 1994-01-12 | 1997-08-12 | Advantest Corporation | Non-contact type wave signal observation apparatus |
| JP4071044B2 (en) * | 2002-02-08 | 2008-04-02 | 株式会社ダイヘン | Impedance matching device output end characteristic analysis method, impedance matching device, and impedance matching device output end characteristic analysis system |
| JP4088499B2 (en) * | 2002-08-28 | 2008-05-21 | 株式会社ダイヘン | Impedance matching device output end characteristic analysis method, impedance matching device, and impedance matching device output end characteristic analysis system |
| US7215266B2 (en) * | 2004-05-21 | 2007-05-08 | Wionics Research | Hybrid DC offset cancellation scheme for wireless receiver |
| JP7261024B2 (en) * | 2019-02-01 | 2023-04-19 | 一般財団法人電力中央研究所 | Evaluating Comparison Function for Transformer Windings |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62140614A (en) * | 1985-12-16 | 1987-06-24 | Matsushita Electric Ind Co Ltd | Deodorizing and dust-collecting filter for cleaning air |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3338193C2 (en) * | 1983-10-20 | 1987-05-14 | Institut für Rundfunktechnik GmbH, 8000 München | Circuit arrangement for measuring the quantization noise or the empty channel noise or the total distortion of a digital audio device |
| JP2537052B2 (en) * | 1987-06-04 | 1996-09-25 | 日本ヒューレット・パッカード株式会社 | Settling characteristics measurement method |
| DE3931934C2 (en) * | 1988-10-03 | 1994-11-10 | Olympus Optical Co | Image input / output device |
-
1990
- 1990-10-31 JP JP2295095A patent/JP3045759B2/en not_active Expired - Fee Related
-
1991
- 1991-10-10 DE DE19914133619 patent/DE4133619C2/en not_active Expired - Fee Related
- 1991-10-15 GB GB9121846A patent/GB2249842B/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62140614A (en) * | 1985-12-16 | 1987-06-24 | Matsushita Electric Ind Co Ltd | Deodorizing and dust-collecting filter for cleaning air |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2249842B (en) | 1994-12-14 |
| DE4133619A1 (en) | 1992-05-07 |
| DE4133619C2 (en) | 1997-03-27 |
| JPH04168371A (en) | 1992-06-16 |
| GB9121846D0 (en) | 1991-11-27 |
| JP3045759B2 (en) | 2000-05-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6230106B1 (en) | Method of characterizing a device under test | |
| Engen | A (historical) review of the six-port measurement technique | |
| US8519719B2 (en) | System for complex impedance measurement | |
| EP0035391A2 (en) | Multi frequency eddy current test apparatus and method | |
| US5591913A (en) | Apparatus and method for ultrasonic spectroscopy testing of materials | |
| JPS62189057A (en) | Method for compensating eddy current by magnetic field gradient | |
| KR940701568A (en) | Method and apparatus for testing hardening | |
| US4686457A (en) | Method for measuring a signal's frequency components | |
| Greening et al. | Comparison of shear wave velocity measurements in different materials using time and frequency domain techniques | |
| Schoukens et al. | A sinewave fitting procedure for characterizing data acquisition channels in the presence of time base distortion and time jitter | |
| GB2249842A (en) | Measuring settling characteristics of devices | |
| US5051916A (en) | Stimulus signal generation method to maximize dynamic range in frequency response function calculations | |
| Borkowski | LIDFT-the DFT linear interpolation method | |
| Layer | Theoretical principles for establishing a hierarchy of dynamic accuracy with the integral-square-error as an example | |
| US3634755A (en) | System to measure the frequency domain response of a radar component | |
| JP2006523848A (en) | Single sweep measurement of multiple optical properties | |
| GB2026803A (en) | Defining the maximum and minimum points of a varying electrical signal | |
| DE69105439D1 (en) | Method and device for measuring the integrity of a consignment. | |
| Van der Auweraer et al. | Accurate modal analysis measurements with programmed sine wave excitation | |
| US6343513B1 (en) | Non-destructive evaluation method and apparatus for measuring acoustic material nonlinearity | |
| JPS6394170A (en) | Measuring method for setting characteristics | |
| US4359682A (en) | Method and apparatus for testing the output reflection coefficient of an automatic level controlled source | |
| Riad et al. | Application of the homomorphic deconvolution for the separation of TDR signals occurring in overlapping time windows | |
| Rex et al. | Correlation, Signal Averaging, and Probability Analysis | |
| JP3052754B2 (en) | Semiconductor test equipment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732E | Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20071015 |