JP2005257285A - Automatic measuring system of disturbance waves - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an easy method for detecting a broadband for obtaining optimum VBW, necessary for easy measurement of disturbance waves using a spectrum analyzer in developing an information processor. <P>SOLUTION: Video band widths of the spectrum analyzer 2 are set to a first value and a second value by a VBW switching means 3-2 and peak values of the same frequency are compared by a comparison means 3-8. When the absolute value of the difference exceeds a predetermined value, the wave of that frequency discriminated as being broadband. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention regulates the International Special Committee on Radio Interference (CISPR) in order to measure jamming radio waves that interfere with other devices due to undesired leaked radio waves generated from information processing devices. It is related with the optimal display filter value setting apparatus in the jamming wave automatic measurement apparatus which can detect easily that it passed.

  Information processing devices such as personal computers and printers are obliged to comply with the regulations of each country in order to suppress leaked radio waves. It has been broken.

  For this reason, based on the international standard regulated by the CISPR, a QP value (Quasi-Peak, quasi-peak value) is measured at 10 to 30 points with an electric field strength measuring device called a test receiver at all frequencies of 30 MHz to 1 GHz. It is. The QP value is a value close to the average value between the intermediate values of the peak mode and the average mode, and the QP value can be obtained by measuring with the electric field strength measuring instrument.

When measuring this jamming wave, specifically, rotate the turntable on which the measurement target device (EUT: Equipment Under Test) is mounted 360 degrees, and change the antenna height to 1 to 4 meters to the maximum value. Measure. At this time, if the turntable is rotated 360 degrees, it takes 30 seconds to 60 seconds, and the lifting and lowering of the antenna takes 20 seconds to 30 seconds. (For example, refer nonpatent literature 1.)
Akira Bando, “Fundamental Noise Countermeasures” [online], April 1998, published by TDK Corporation, THE HOTLINE Vol. 27 (see page 20, Tips-1) [searched on January 22, 2004], Internet <URL: http://www.tdk.co.jp/tjbcd01/bcd27-30.pdf Formal QP measurement Then, for each frequency to be measured, these are repeated to find and fix the maximum radio wave radiation angle and height, and the maximum value observation for 15 seconds specified in CISPR is performed, so it takes several hours to measure the QP value. There is a problem. In addition, at the time of device development, in order to achieve the effect of countermeasures for suppressing jamming radio waves, countermeasure measures are often measured several tens of times, and measuring the QP value with a test receiver every time is time consuming and impractical.

  For this reason, simple measurement is often performed in a short time using the peak (peak value) measurement function of a spectrum analyzer (hereinafter referred to as a spectrum analyzer). When the countermeasure measurement is repeated several tens of times in this peak measurement and reaches a passing level, only a frequency that is likely to cause a problem (for example, CPU drive frequency) is officially measured by a test receiver.

  As described above, the peak measurement using the spectrum analyzer has an advantage that it can be easily measured in a short time. For that purpose, the spectrum measurement of the spectrum analyzer is close to the QP value measurement measured by an electric field strength measuring device called a test receiver. It is necessary to obtain results.

  In conventional interference signal measurement by a spectrum analyzer, the spectrum filter for the spectrum analyzer screen (VBW: Video Band Width) is set to a small value such as 10 KHz or 3 KHz as a filter enhancement inside the spectrum analyzer in order to remove static noise and the like of antenna elevation. It was. The input filter (RBW: Resolution Band Width) of the spectrum analyzer is set to 120 KHz or 100 KHz which is the same as the QP bandwidth of the CISPR standard.

  By the way, there are narrowband and broadband as types of jamming. In recent personal computers, the CPU drive pulse frequency is fast, for example, 1 GHz or more, but this frequency is not fixed but is gradually decreased to a certain time, for example, -1%, and is increased to 1 GHz again. A spread spectrum clock (SSC) system that repeats at a cycle of 10 KHz is used. If the drive frequency is fixed, even if the leak is weak, even if the same state continues for a long time, the adverse effect will occur.By changing the frequency, this adverse effect will be dispersed and no actual harm will occur. By doing. The jamming radio wave based on this frequency spreading method is called broadband, and the jamming radio wave when the driving frequency is fixed is called a narrow band.

  In the narrow band, even if the value of VBW is changed, there is almost no influence on the spectrum measurement of the spectrum analyzer, and in the conventional information processing apparatus, there is no particular problem because the narrow band radiation is mainly used.

  However, in recent information processing devices, the number of devices that use the frequency spread method has increased, and circuits using this frequency spread method have broadband with a frequency that fluctuates at a constant rate every fixed time with respect to the basic frequency. Will be emitted. However, in broadband, if the value of VBW is small, peak measurement is performed with a value that is several dB smaller than the QP value measured by the test receiver. Conversely, if the value of VBW is too large, the peak value is measured several dB higher than the QP value.

  In the development stage of information processing equipment, in order to suppress the output of jamming radio waves, dozens of preventive measures and measurement of the jamming radio waves are often performed for the place where jamming radio waves are estimated to be generated. In order to make an approximate measurement, peak measurement is often performed using a spectrum analyzer, but this peak measurement result should be close to the QP value measurement result by the test receiver.

  However, in reality, many information processing equipment developers do not know such VBW problems, rely on the spectrum analyzer's peak measurement values, proceed with countermeasures against jamming, and determine that the countermeasures are complete and formally test them. When we measured the QP value at the receiver, it was often the case that it was a development delay such as recognizing that it was not acceptable for the first time at that time and taking measures again.

  Conversely, when VBW is set to a large value such as 300 KHz and the spectrum analyzer peak measurement is performed, a value that is larger than the QP value measured by the test receiver is measured, and it is judged that it was originally rejected even if it passed. There is also a problem that, after taking unnecessary and excessive measures, there is a problem of increasing the cost of the apparatus, and it is noticed for the first time after measuring the QP value of the test receiver.

  That is, redoing occurs even if the value of VBW is too large or small.

  A procedure for starting countermeasures against jamming of a conventional information processing apparatus will be described with reference to FIG.

  S1. First, various measures are taken so that the interference radio wave is not output to the information processing apparatus under development. It takes several minutes to several hours to take this measure.

  S2. As a simple measurement, measure the peak of the jamming wave with a spectrum analyzer and measure whether it is within the regulation range. It can be done in about 30 minutes.

  S3. If this measurement result exceeds the regulation value, that is, if it fails, the process returns to S1 and further measures are taken for the information processing apparatus under development. However, if it passes within the regulation value, the process proceeds to the next step S4.

  S4. If the test passes in S3, the test receiver is used to rotate the turntable 360 degrees, and perform an official QP measurement such as changing the antenna height by 1 to 4 meters. This measurement takes several hours.

  S5. And what passed the determination by formal QP value measurement in this S4 is completion of countermeasures. However, those that fail are returned to S1. That is, when the official QP value measurement result by the test receiver is different from the peak measurement result by the spectrum analyzer, the test is performed again.

  It may be possible to set the VBW value based on past experience as a measure to prevent this re-execution. However, since what KHz is appropriate as the VBW value differs depending on the device, the spectrum measurement of the spectrum analyzer matches the QP value. Regardless of whether or not to do so, simply setting the VBW value from past experience does not always solve the problem.

  The spectrum analyzer also has a function of the QP mode, and means for measuring all frequencies in the spectrum analyzer QP mode can be considered, but this requires more time than the QP measurement of the test receiver and is not practical.

  In order to solve the above-described problems, the present invention is configured as follows (1) to (4).

  (1) An interference radio wave automatic measuring apparatus including a spectrum analyzer that measures a peak value for each frequency of a received radio wave and a field intensity measuring device that measures a quasi-peak value of the received radio wave. Provided is a screen display filter whose width can be variably set, VBW switching means for controlling the video bandwidth, and peak value reading means for indicating the number of peak values read by the spectrum analyzer and holding the read value QP value reading means for holding the quasi-peak value measured by the electric field strength measuring device, frequency switching means for switching the frequency for scanning the measurement range of the spectrum analyzer, and the quasi-peak measured by the electric field strength measuring device. Compare the peak value with the peak value measured by the spectrum analyzer, or the peak value before and after controlling the video bandwidth A controller having comparison means for comparison is provided, and the video bandwidth of the spectrum analyzer is set to the first value and the second value by the VBW switching means, and the peak value of the same frequency at that time is set by the comparison means. In comparison, when the absolute value of the difference is equal to or greater than a predetermined value, radio waves of this frequency are determined as broadband.

  (2) In the interference radio wave automatic measuring device described in (1) above, a quasi-peak value is measured by an electric field intensity measuring device at one frequency determined to be broadband and held by the QP value reading means. The video bandwidth value of the spectrum analyzer is changed to a plurality of predetermined values by the VBW switching means, the peak values are measured and held by the peak value reading means, and the spectrum is measured by the comparing means. The peak value closest to the quasi-peak value in the spectrum analyzer is obtained by comparing each peak value measured by the analyzer with the quasi-peak value and determining the video bandwidth value with the smallest absolute value of the difference. It is characterized by obtaining the video bandwidth from which the value is obtained.

  (3) In the automatic interference wave measuring device described in (2) above, only the broadband frequency obtained in claim 1 is fixed to the turntable on which the information processing device to be measured is mounted, and the device to be measured A quasi-peak value is measured by the electric field strength measuring device while fixing the height of an antenna that receives jamming radio waves generated from an information processing device.

  (4) In the automatic interference radio wave measuring apparatus described in (2) above, a quasi-peak value is measured by an electric field strength measuring device at one frequency determined to be broadband and held by the QP value reading means. The video bandwidth value of the spectrum analyzer is changed to a plurality of predetermined values by the VBW switching means, the peak values are measured and held by the peak value reading means, and the spectrum is measured by the comparing means. The peak value closest to the quasi-peak value in the spectrum analyzer is obtained by comparing each peak value measured by the analyzer with the quasi-peak value and determining the video bandwidth value with the smallest absolute value of the difference. The video bandwidth from which the value is obtained is set to the spectrum analyzer as the optimal video bandwidth, and all frequencies defined as the measurement range are set. And performing measurement of jamming against.

  The present invention has the following effects (1) to (4).

  (1) Even if the video bandwidth is set to a different value for the narrow band, it is hardly affected. Therefore, it is necessary to detect the broadband and perform peak measurement in the spectrum analyzer. It is necessary to remove it. The present invention can extract broadband frequencies very easily.

  (2) According to the present invention, since it is possible to easily obtain a video bandwidth closest to the quasi-peak value, it is possible to obtain an accurate line-of-sight outlook at the stage of peak value measurement by a spectrum analyzer.

  (3) For only the broadband frequency obtained in (1) above, the turntable is fixed and the antenna height is fixed, and the quasi-peak mode measurement is performed with the electric field strength measuring device under certain conditions. The quasi-peak value required before measurement can be easily obtained.

  (4) Since the optimum video bandwidth value obtained in (2) above is set in the spectrum analyzer and the peak value is measured in the entire frequency range, the value is almost the same as the quasi-peak value obtained by the field strength measuring device. Therefore, it is possible to prevent the wrong judgment from being made in the spectrum analyzer.

  In interfering radio wave measurement using a spectrum analyzer, a broadband frequency is first detected by obtaining a difference between peak values by changing a video bandwidth value of a display filter. At this broadband frequency, the turntable and the antenna height are fixed and the quasi-peak value is measured by an electric field strength measuring device called a test receiver (hereinafter referred to as a test receiver). Next, using the spectrum analyzer again, change the video bandwidth to measure the peak value, compare each peak value with the quasi-peak value, and obtain the peak value closest to this quasi-peak value. The video bandwidth is obtained, this video bandwidth is set in the display filter, and the peak values of all frequencies in the jamming measurement range are measured.

  In this way, the peak value is measured by setting the optimal video bandwidth for which the peak value closest to the quasi-peak value measured by the field strength measuring instrument is obtained in the display filter and measuring the peak value. Since the peak value can be almost the same as the peak value, a peak value by a spectrum analyzer very close to the quasi-peak value can be obtained in a short time, and determination errors can be substantially prevented.

  An embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 illustrates an embodiment of the present invention (FIG. 2), FIG. 3 illustrates an embodiment of the present invention (part 2), and FIG. 4 illustrates a video bandwidth (VBW). FIG. 5 is an explanatory diagram of the difference between the peak value of the spectrum analyzer and the quasi-peak value (QP value) of the test receiver when changed, FIG. 5 is an explanatory diagram of the peak value measurement status by the spectrum analyzer, and the QP value measurement status by the test receiver, FIG. These are explanatory drawings of the state of interference wave measurement in the development of an information processing apparatus using the present invention.

  In the figure, 1 is an electric field strength measuring device, 2 is a spectrum analyzer, 3 is a controller, 4 is a turntable controller, 5 is an antenna lifting platform controller, 10 is an antenna lifting platform, 11 is an antenna, 12 is a coaxial cable, 13 is a wooden desk, 14 is a turntable and 15 is a device under test.

  The test receiver 1 measures a QP value, which is a quasi-peak value, based on an international standard that defines the intensity of jamming waves generated from an information processing device by CISPR.

  The spectrum analyzer 2 can measure the peak value of the intensity of the jamming wave generated from the information processing apparatus in a shorter time than the measurement by the test receiver 1. The spectrum analyzer 2-0 and the input filter (RBW) : Resolution Band Width) 2-1 and display filter (VBW: Video Band Width) 2-2. When the disturbing radio wave is measured, the peak value is continuously displayed on the display unit 2-0 as shown in FIGS. 5A and 5B described later. The input filter 2-1 is set to 120 KHz or 100 LHz, which is the same as the QP bandwidth defined by CISPR. This setting is performed by the RBW switching unit 3-3 of the controller 3.

  Further, the spectrum analyzer 2 has an automatic peak search means for automatically detecting the peak value of the measured and displayed data. The auto peak search means sequentially extracts M (for example, M = 8) from the largest peak values measured by the spectrum analyzer 2 and is not shown.

  The display filter 2-2 is for noise removal. When VBW is set to a small frequency value, the peak value measured by the spectrum analyzer 2 is measured several dB smaller than the quasi-peak value measured by the test receiver 1, and conversely If it is too large, it is measured several dB higher than the quasi-peak value, and an optimum VBW setting corresponding to the device under test 15 is required. This VBW setting switching is performed by the RBW switching means 3-3.

  The controller 3 controls the interference wave generated from the device under test 15 for the broadband detection in the present invention, the control for the VBW detection optimum for the device under test, the control for measuring the electric field strength by the spectrum analyzer, etc. In addition, it controls whether or not the device under test has cleared CISPR regulations using a test receiver, and includes antenna control means 3-0, turntable control means 3-1, VBW switching means 3-2. RBW switching means 3-3, Peak value reading means 3-4, broadband extraction means 3-5, QP value reading means 3-6, frequency switching means 3-7, comparison means 3-8, and the like.

  Here, the antenna control means 3-0 controls the vertical movement of the antenna lift 10 and changes the height of the antenna 11 for measuring interference radio waves attached thereto by 1 to 4 meters.

  The turntable control means 3-1 controls the device under test 15 such as a personal computer or a printer placed on the wooden desk 13 on the turntable 14 by rotating the turntable 14 360 degrees.

  The VBW switching means 3-2 controls the switching of the video bandwidth value VBW of the display filter 2-2 of the spectrum analyzer 2 to any one of 1 kHz, 3 kHz, 10 kHz, 30 kHz, 100 kHz, and 300 kHz as shown in FIG. It is. In this embodiment, the VBW value to be changed is 1 KHz to 300 KHz, which is determined by the span width of the spectrum analyzer 2 and the sweep time. The VBW value changes logarithmically like 300 Hz, 1 KHz, 3 KHz, 10 KHz, 30 KHz, 100 KHz, 300 KHz, etc., and an intermediate value cannot be set.

  The lower limit is a VBW value of 1 KHz or 3 KHz that makes the sweep time less than 500 msec when the spanner screen is enlarged to make it easy to see, that is, about 10 MHz. is there. If it is less than this, the sweep time will be delayed, and the effect of the short-term preliminary measurement will be reduced.

  The upper limit is the minimum value of the QP detection bunt width of 120 KHz or more, that is, 300 KHz defined by the CISPR standard. Since it is clear that a value larger than this is measured to be larger than the QP value, it is changed in the range of 1 KHz to 300 KHz.

  The RBW switching unit 3-3 sets the value of the input filter 2-1 of the spectrum analyzer 2 to 120 KHz or 100 KHz which is the same as the QP bandwidth of the CISPR standard.

  The Peak value reading means 3-4 instructs the automatic peak search means of the spectrum analyzer 2 to read the number of peaks to be read, and reads and controls the value measured by the spectrum analyzer 2 at this peak value.

  The broadband extraction means 3-5 detects whether or not the peak value of the spectrum analyzer 2 at a certain frequency has changed by a predetermined value or more by changing the VBW value of the spectrum analyzer 2 from 10 KHz to 30 KHz, for example, and the frequency is narrow band. For example, if there is a difference of 2 dBμv or more, it is identified as broadband.

  The QP value reading means 3-6 reads the quasi-peak value measured by the test receiver 1 in accordance with an instruction from the controller 3, and temporarily holds it.

  For example, when the spectrum switching unit 3-7 scans and displays a peak value in the range of 30 MHz to 1 GHz, for example, in the spectrum analyzer 2, the frequency range is too wide to output and display this at a time. The instructed control signal is output.

  The comparison means 3-8 obtains the difference between the peak values measured by the spectrum analyzer 2, or obtains the difference between the quasi-peak value obtained by the electric field strength measuring instrument 1 and the peak value measured by the spectrum analyzer 2.

  The antenna lifting platform 10 changes the height of the antenna 11 by moving up and down in the range of, for example, 1 to 4 meters.

  The antenna 11 receives the jamming radio wave output from the device under test 15. The radio wave received by the antenna 11 is transmitted to the electric field strength measuring device 1, the spectrum analyzer 2, etc. by the coaxial cable 12.

  The wooden desk 13 has a device under test 15 mounted thereon, and the turntable 14 controls the rotation thereof by 360 degrees.

  The device under test 15 is an information processing device such as a personal computer or a printer under development, for example, and it is tested whether or not the radiated interference is within the CISPR regulations.

  The antenna lift 10, the antenna 11, the wooden desk 13, the turntable 14, the device under test 15, etc. are arranged in an anechoic chamber 16.

  The operation of the present invention will be described based on the flow shown in FIGS.

  S1. First, when the measurement of the interference radio wave intensity output from the device under test 15 by the spectrum analyzer 2 is started, the turntable 14 and the antenna lifting platform 10 are arranged in the anechoic chamber 16 shown in FIG. A device under test 15 such as a personal computer or a printer is placed on the table 14, and an antenna 11 is mounted on the antenna lift 10 so as to be able to move up and down by 1 to 4 meters, and measurement of the interference radio wave intensity is started.

  S2. At the start of measurement, the antenna 10 is fixed so that the antenna height does not move up and down and the turntable 14 does not rotate. As a result, it is possible to measure the interference wave by the spectrum analyzer 2 without taking time.

  S3. All frequencies in the measurement range of 30 MHz to 1 GHz are displayed on the display screen which is the display means 2-0 of the spectrum analyzer 2. As a result, waveforms as shown in FIGS. 5A and 5B are displayed. FIGS. 5A and 5B are in a state where VBW is set to 10 KHz and 30 KHz. Since VBW is not set in the first measurement, it is not the same as FIGS. 5A and 5B. However, such a waveform corresponding to the frequency-received radio wave intensity is displayed.

  S4. Next, control for broadband extraction is performed. The broadband extraction unit 3-5 controls the RBW switching unit 3-3, and the control signal from the RBW switching unit 3-3 causes the input filter 2-1 of the spectrum analyzer 2 to be 120 KHz which is the same as the QP bandwidth of the CISPR standard. Alternatively, one value of 100 KHz, for example, 100 KHz is set.

  S5. Then, a plurality of m points (for example, m = 3 points) of peak values greater than a predetermined value are extracted by auto-peak search means (not shown) provided in the spectrum analyzer 2, and the frequency is held in spectrum analyzer 2. Thereby, for example, 240 MHz, 285 MHz, and 400 MHz are extracted.

  S6. Then, the display filter VBW of the spectrum analyzer 2 is set to 10 KHz.

  S7. The broadband extraction unit 3-5 first instructs the Peak value reading unit 3-4 to read the peak value of the first point at m = 1. As a result, the spectrum analyzer 2 measures the peak value PKV1 of the 240 MHz interference radio wave when the VBW is 10 KHz. The Peak value reading means 3-4 receives the 240 MHz peak value PKV1-1 from the spectrum analyzer 2 with m = 1. It substitutes for holding part 3-5-0 of broadband extraction means 3-5.

  S8. The broadband extraction unit 3-5 sets VBW to 30 KHz.

  S9. The Peak value reading means 3-4 receives from the spectrum analyzer 2 the reading value of the peak value PKV1-2 of 240 MHz jamming radio waves, which is the first point of m = 1 when VBW is 30 KHz, and the broadband extraction means 3-5 Assigned to the holding unit 3-5-0.

  S10. The broadband extraction means 3-5 calculates the difference between the peak value PKV1-1 at the first point when the VBW is 10 KHz and the peak value PKV1-2 at the first point when the VBW is 30 KHz, and the absolute value of the difference It is determined whether or not the value Abs is greater than 2 dB. If it is larger than 2 dB, the process proceeds to the next step S11. However, if it is not larger than 2 dB, the processing after S6 is performed on the frequency of the next point (m = m + 1), in this example, 285 MHz where m = 1 + 1.

  S11. If the difference between the peak value when VBW is 10 KHz and the peak value when 30 KHz is 2 dB or more in S10, broadband extraction means 3-5 determines that the frequency at this point is broadband. At this frequency, an optimum VBW is searched as described later. In the example of FIGS. 5A and 5B, 240 MHz and 285 MHz indicate a narrow band, and 400 MHz indicates a broadband.

  S12. QP mode measurement is performed using the test receiver 1 for the frequency FB determined to be broadband in S6 to S11. For this reason, the broadband extraction unit 3-5 instructs the test receiver 1 to perform QP mode measurement on the frequency FB determined to be the broadband. In this measurement, the turntable 14 does not rotate, the antenna height is fixed, and only the frequency FB is measured in the QP mode. The QP measurement value QPV is transmitted to the QP value reading unit 3-6 and held in the holding unit 3-6-0. As a result, for example, as shown in FIG. 4, a QP measurement value 29 dB is measured and held.

  S13. Next, control for obtaining an optimum VBW when measuring the spectrum analyzer 2 in the peak mode will be described.

  S14. As initial value settings, for example, variables VBV = 0 and QPD = 99 are set in the memory of the controller 3 (not shown). Here, the final value of VBV indicates the optimum VBW value, and QPD indicates the difference between the QP value and the peak value. These settings are performed under the control of the broadband extraction means 3-5.

  S15. Next, VBW of the spectrum analyzer 2 is set to 10 KHz.

  S16. Then, the peak value reading unit 3-4 performs reading control of the peak value of the spectrum analyzer 2 having the broadband frequency, and the peak value PKV is held by the holding unit 3-5-0 of the broadband extracting unit 3-5. As a result, the Peak value 24 dB shown in FIG. 4 is read and held.

  S17. Then, it is recognized whether or not the absolute value Abs of the difference between the read value = 24 and the QPV = 29 measured in S12 is smaller than the QPD set in S14. If it is larger, the process proceeds to S20 described later.

  S18. If it is smaller than QPD, the absolute value Abs (peak reading value−QPV) obtained in S17 is entered as QPD which is the difference between the QP value and the peak value. As a result, Abs (24-29) = 5 is entered as the QPD.

  S19. Then, enter 10 as VBV. That is, the VBW value that minimizes the difference from the QP value is entered.

  S20. Next, the VBW of the spectrum analyzer 2 is set to 30 KHz.

  S21. Then, the peak value of the spectrum analyzer 2 having the same broadband frequency as in S16 is read, and the peak value PKV is held by the holding unit 3-5-0. As a result, the Peak value 28 dB shown in FIG. 4 is read and held.

  S22. Then, it is recognized whether or not the absolute value Abs of the difference between the read value = 28 and the QPV = 29 is smaller than the QPD set in S18. If not smaller, the process proceeds to S25 described later. In this case, since the read value is 28, the QPV is 29, and the QPD is 5, the process proceeds to the next S23.

  S23. When the absolute value is smaller than the QPD in S22, the absolute value Abs (28-29) = 1 obtained in S22 is obtained as a new QPV as the QPD that is the difference between the QP value and the peak value, and the holding unit Held at 3-8-0.

  S24. Then, 30 is entered as VBV. That is, the VBW value with the smallest difference from the QP value is entered.

  S25. Next, the VBW of the spectrum analyzer 2 is set to 100 KHz.

  S26. Then, the peak value of the spectrum analyzer 2 having the same broadband frequency as that of S16 and S21 is read, and the peak value PKV is held by the holding unit 3-5-0. As a result, the Peak value 32 dB shown in FIG. 4 is read and held.

  S27. Then, it is recognized whether or not the absolute value Abs of the difference between the read value = 32 and the QPV = 29 is smaller than the QPD set in S23. If not smaller, the process proceeds to S30 described later. In this case, since the read value is 32, the QPV is 29, and the QPD is 1, the process proceeds to S30 described later.

  S28. If the absolute value is smaller than the QPD in S27, the absolute value Abs (reading value−QPV) obtained in S27 is entered as a new QPD.

  S29. Then, 100 set in S25 is entered as VBV.

  S30. However, since the difference between the read value and the QPV is not smaller than the QPD set in S23 in S27, the value of VBV = 30 entered in S24 is read and set to VBW.

  S31. It can be determined that the VBV obtained in this way is the VBW value that can obtain the closest value to the QP value measured by the test receiver 1 when measuring the peak value of the spectrum analyzer 2. The QP value measured by the test receiver 1 is set to VBW, the rotation of the turntable 14 is controlled, and the measurement based on the normal interference regulation that controls the height of the antenna 11 up and down by 1 to 4 meters is started. The same level of interference measurement can be performed.

  In FIGS. 2 and 3, for the sake of simplicity of explanation, the case where VBW is set to 10 KHz, 30 KHz, and 100 KHz to obtain the optimum VBW has been described. However, the present invention is not limited to this, and FIG. As shown in FIG. 4, even when VBW is set to 1 KHz to 300 KHz, it can be similarly implemented.

  As shown in FIG. 4, the developed information processing apparatus has conventionally measured the interference radio wave intensity with a spectrum analyzer at VBW = 10 KHz, so that the peak value margin with respect to the regulation limit value of 30 dB is 6 dB. There was a false level with a passing level.

  However, according to the present invention, the peak value is measured while changing the VBW of the spectrum analyzer, and the VBW that obtains the peak value closest to the QP value is found. As shown in FIG. 4, for example, when the VBW is 30 KHz, the closest to the QP value. Since this is set in the spectrum analyzer and the peak value is measured, a value close to the QP value measurement can be obtained by the peak value measurement. For example, in the case of the apparatus shown in FIG. 4, when VBW is 30 KHz, the margin is only 1 dB and it is close to the QP value.

  In this description, an example in which VBW = 30 KHz is optimal has been described. However, some devices other than 30 KHz are optimal (close to QP), and the present invention is not limited to this.

  As shown in FIG. 5C, in the QP measurement, the center of the circle indicates the measured value, and the straight line described below the circle indicates the frequency position.

  In FIG. 5, a straight line having a difference at 230 MHz indicates the limit of the interference radio wave intensity. 230 MHz indicates the upper frequency limit of TV commercial broadcasting (12 channels, VHF). It shows that the limit changes from 30 dBμV to 37 dBμV.

  An efficient measurement operation of jamming radio waves using the above-described broadband extraction method and the method for obtaining the optimum VBW will be described with reference to FIG.

  S100. First, various measures are taken so that the interference radio wave is not output to the information processing apparatus under development.

  S101. 2 and 3, the broadband is extracted, the VBW from which the peak value closest to the QP value is obtained is obtained, and this is set in the spectrum analyzer.

  S102. The peak value is measured with the spectrum analyzer set by the VBW.

  S103. A pass / fail prediction is made by the spectrum analyzer measurement in S102, and if it fails, the process returns to S100 to take measures against the apparatus.

  S104. For those with a prospect of passing, a QP measurement is officially performed based on the CISPR standard using a field strength measuring device called a test receiver.

  S105. Then, a formal determination is made, and if it passes, the measurement of the interference radio wave is completed.

  In the conventional measurement, there is a case where the prospect of passing in S3 shown in FIG. 7 is rejected in the case of formal determination in S5, and there are many examples in which countermeasures are required for the apparatus. .

  However, according to the present invention, the VBW setting of the spectrum analyzer can be performed so that the QP value and the peak value coincide with each other, so that the formal measurement is passed almost once and the redo is almost unnecessary.

  According to the present invention, the optimal VBW close to the QP measurement can be set in the spectrum analyzer, and the prospect of pass / fail can be efficiently and accurately performed, so that the information processing apparatus can be developed in a short time.

It is one Example of this invention. It is operation | movement explanatory drawing (the 1) of the Example of this invention. It is operation | movement explanatory drawing (the 2) of the Example of this invention. It is explanatory drawing of the difference of the peak value of a spectrum analyzer when a video bandwidth (VBW) is changed, and the quasi-peak value (QP value) of an electric field strength measuring device. It is explanatory drawing of the peak value measurement state by a spectrum analyzer, and the QP value measurement state by an electric field strength measuring device. It is an interference electric wave measurement state explanatory view in information processor development using the present invention. It is explanatory drawing of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric field strength measuring device 2 Spectrum analyzer 3 Controller 4 Turntable controller 5 Antenna lifting platform controller 10 Antenna lifting platform 11 Antenna 12 Coaxial cable 13 Wooden desk 14 Turntable 15 Device under test 16 Anechoic chamber

Claims (4)

In a spectrum analyzer that measures the peak value for each frequency of the received radio wave, and an automatic interference wave measuring device that includes an electric field strength measuring device that measures the quasi-peak value of the received radio wave,
The spectrum analyzer is provided with a screen display filter that can variably set the video bandwidth,
VBW switching means for controlling the video bandwidth;
The peak value reading means for indicating the number of peak values read by the spectrum analyzer and holding the read value;
QP value reading means for holding the quasi-peak value measured by the electric field strength measuring device;
Frequency switching means for switching the frequency for scanning the measurement range of the spectrum analyzer;
A controller having comparison means for comparing the quasi-peak value measured by the electric field strength measuring instrument with the peak value measured by the spectrum analyzer or comparing the peak value before and after controlling the video bandwidth is provided. ,
The video bandwidth of the spectrum analyzer is set to the first value and the second value by the VBW switching means, the peak values of the same frequency at that time are compared by the comparing means, and the absolute value of the difference is previously determined. An interference radio wave automatic measuring device characterized by discriminating radio waves of this frequency as broadband when it exceeds a predetermined value. In the automatic interference wave measuring device according to claim 1,
A quasi-peak value is measured by an electric field strength measuring device at one frequency determined to be broadband and held by the QP value reading means,
The peak value is measured by changing the video bandwidth value of the spectrum analyzer to a plurality of predetermined values by the VBW switching means, and these are held by the peak value reading means,
By comparing each peak value measured by the spectrum analyzer by the comparing means with the quasi-peak value, and obtaining a video bandwidth value having the smallest absolute value of the difference, the spectrum analyzer uses the quasi-peak value. An apparatus for automatically measuring jamming radio waves, which obtains a video bandwidth that provides a peak value closest to the peak price. In the automatic interference wave measuring device according to claim 2,
Only the broadband frequency obtained in claim 1 is
Measure the quasi-peak value with the field strength measuring instrument with the turntable on which the information processing device to be measured is mounted fixed and the height of the antenna that receives the jamming waves generated from the information processing device to be measured fixed An interference radio wave automatic measuring device characterized by that. In the automatic interference wave measuring device according to claim 2,
A quasi-peak value is measured by an electric field strength measuring device at one frequency determined to be broadband and held by the QP value reading means,
The peak value is measured by changing the video bandwidth value of the spectrum analyzer to a plurality of predetermined values by the VBW switching means, and these are held by the peak value reading means,
By comparing each peak value measured by the spectrum analyzer by the comparing means with the quasi-peak value, and obtaining a video bandwidth value having the smallest absolute value of the difference, the spectrum analyzer uses the quasi-peak value. The video bandwidth that provides the peak value closest to the peak value is set as the optimum video bandwidth in the spectrum analyzer, and the interference radio waves are measured for all frequencies defined as the measurement range. Automatic interference measurement device.

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