Noise measurement program, noise measurement method, and noise measurement device

Abstract

To reduce the number of measurement times in near electromagnetic field measurement of a circuit board.SOLUTION: A noise measurement program allows a computer to execute acquisition of time-series data for showing electromagnetic field strength from a measured circuit that is measured during measurement time having a time interval of at least one wavelength of a reference signal in synchronization with a trigger detected based on a signal waveform of a reference signal inputted to a measured circuit that performs switching operation following a reference signal in each of multiple measurement points set near the measured circuit, and extraction of time-series data in a designated section that is designated by time width shorter than time width of measurement time from acquired time-series data, calculation of electromagnetic field strength and phase components at a designated frequency that is designated regarding each of multiple measurement points on the basis of time-series data in a designated section, and output of a plane vector corresponding to electromagnetic field strength and phase components regarding multiple measurement points under a condition of a designated section and a designated frequency.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a noise measurement program, a noise measurement method, and a noise measurement device.

Background Art

[0002] Conventionally, in order to evaluate noise in a circuit board built in an electronic device, a technique related to near-field electromagnetic field measurement for measuring a near-field electromagnetic field distribution indicating the intensity distribution of an electric field / magnetic field generated from the board is known. Near-field electromagnetic field measurement can obtain the distribution of near-field electromagnetic field intensity at each of a plurality of measurement points by scanning a measurement probe in the vicinity of the circuit board to be measured. Further, by rotating the probe at each of the plurality of measurement points and measuring the magnetic field intensity at a plurality of angles, the maximum value of the magnetic flux at each of the plurality of measurement points can be obtained, so that the current direction in the board to be measured can be estimated.

[0003] However, since the near-field electromagnetic field distribution changes according to measurement conditions such as the section and frequency extracted from the time waveform of the electric field / magnetic field intensity, it is necessary to perform near-field electromagnetic field measurement for each measurement condition. Further, in order to estimate the current direction, it is necessary to perform near-field electromagnetic field measurement for each of a plurality of angles for each measurement condition. Under such circumstances, when performing multiple measurements, there is a risk of deterioration in repeatability and reproducibility due to, for example, human error or the rotation accuracy of the probe.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem to be solved by the present invention is to reduce the number of measurements in the measurement of the electromagnetic field in the vicinity of a circuit board.

Means for Solving the Problem

[0006] In order to solve the above-described problems and achieve the object, a noise measurement program according to one aspect of the present invention causes a computer to acquire time-series data and output a plane vector. The time-series data indicates the electromagnetic field strength from the circuit under measurement measured at each of a plurality of measurement points set in the vicinity of the circuit under measurement. The circuit under measurement switches according to a reference signal. The time-series data is measured in synchronization with a trigger detected based on the signal waveform of the reference signal input to the circuit under measurement. The time-series data is measured with a measurement time having a time width of one wavelength or more of the reference signal. Outputting the plane vector includes extracting time-series data of a specified section specified with a time width shorter than the time width of the measurement time from the acquired time-series data. Outputting the plane vector includes calculating the electromagnetic field strength and the phase component at a specified frequency specified for each of the plurality of measurement points based on the time-series data of the specified section. The plane vector corresponds to the electromagnetic field strength and the phase component for the plurality of measurement points under the conditions of the specified section and the specified frequency. Calculating the electromagnetic field strength and phase components at a specified frequency for each of the plurality of measurement points based on the time-series data of the specified interval includes calculating a power spectrum from the time-series data of the specified interval by fast Fourier transform, and respectively obtaining the electromagnetic field strength and the phase components at the specified frequency from the calculated power spectrum for each of the plurality of measurement points.

Effect of the Invention

[0007] According to the present invention, the number of measurements in the measurement of the electromagnetic field in the vicinity of a circuit board can be reduced.

Brief Description of the Drawings

[0008]

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DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, each embodiment of the noise measurement program, noise measurement method, and noise measurement apparatus according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited by these embodiments.

[0010] FIG. 1 is a block diagram showing an example of the configuration of a noise measurement apparatus 1 according to an embodiment. FIG. 2 is a schematic diagram showing an example of a DCDC power supply board as a circuit board 2 to be measured according to the embodiment.

[0011] The noise measurement apparatus 1 according to the embodiment is an apparatus that measures the electromagnetic field strength distribution and the current vector indicating the direction of the current generated in the circuit to be measured provided on the circuit board 2 to be measured during the switching operation. Further, the noise measurement apparatus 1 according to the embodiment is an apparatus that outputs a map showing the electromagnetic field strength distribution and / or current distribution in a specified section including an arbitrary timing such as the rising edge or falling edge of the reference waveform of the circuit board 2 to be measured, and at a specified frequency, without performing re-measurement. The noise measurement apparatus 1 is configured to convert the electromagnetic field strength data in a section with an arbitrary time width into electromagnetic field strength distribution data on the frequency axis using fast Fourier transform (FFT), and output a map showing the electromagnetic field strength distribution and / or current distribution corresponding to an arbitrary section and frequency.

[0012] The circuit board 2 to be measured according to the embodiment mounts a circuit to be measured that performs a switching operation according to a reference signal such as a clock signal. As shown in FIG. 2, the circuit board 2 to be measured has an output-side power terminal 21, an output-side ground terminal 22, an input-side power terminal 23, an input-side ground terminal 24, a coil 25, a diode 26, and a control IC 27. As an example, the circuit board 2 to be measured is a power supply circuit having a power conversion circuit that converts power using a power semiconductor device, and a drive circuit that supplies a driving voltage to the power semiconductor device. The circuit board 2 to be measured is, for example, a DCDC power supply board. Hereinafter, the circuit to be measured provided on the circuit board 2 to be measured may also be referred to as the circuit board 2 to be measured.

[0013] As shown in FIG. 1, the noise measurement device 1 according to the embodiment includes a measurement control device 11, a drive control device 12, a drive device 13, a measurement probe 14, an amplifier 15, an oscilloscope 16, a reference probe 17, a storage device 18, and a display control device 19.

[0014] The measurement control device 11 is a device that controls the measurement of the electromagnetic field strength distribution in the noise measurement device 1. The measurement control device 11 functions as the noise measurement device 1 according to the embodiment by executing a program (application program) for realizing the measurement process according to the embodiment. As the measurement control device 11, for example, an information processing device such as a smartphone, a personal computer (PC), or a tablet PC can be appropriately used.

[0015] As shown in FIG. 1, the measurement control device 11 has functions as a measurement condition setting unit 111 and a data combining unit 112.

[0016] The measurement condition setting unit 111 operates the drive device 13 by the drive control device 12 and moves the measurement probe 14 within the measurement scanning range of the noise measurement device 1. Specifically, the measurement condition setting unit 111 transmits a signal S1 to the drive control device 12. Here, the signal S1 includes, for example, coordinate indication information indicating the coordinates of each of a plurality of measurement points and information indicating the rotation angle of the measurement probe 14 at each measurement point. The coordinates of each of the plurality of measurement points are set based on, for example, the scanning range and the measurement resolution. As an example, the measurement condition setting unit 111 instructs the drive control device 12 of the scanning conditions based on the specified movement conditions such as the measurement resolution and the scanning range.

[0017] In addition, the measurement condition setting unit 111 transmits a signal S7 for setting the measurement conditions to the oscilloscope 16. Here, the measurement conditions include a threshold value for trigger detection and a time length for detecting the waveform. Specifically, the measurement condition setting unit 111 sets a measurement time having a time width of one wavelength or more of the reference waveform using the trigger acquired at the rising and falling timings of the reference waveform by the trigger detection unit 161.

[0018] The data combining unit 112 receives, from the drive control device 12, a signal S2 indicating the situation of the current location coordinates, that is, the measurement coordinates which are the current position of the measurement probe 14. Further, the data combining unit 112 receives, from the oscilloscope 16, a signal S8 indicating the waveform data of the electromagnetic field waveform synchronized with the trigger, which is obtained by the waveform acquisition unit 162 of the oscilloscope 16. The data combining unit 112 combines and correlates the information indicated by these two signals S2 and S8, and transmits a signal S9 indicating the electromagnetic field waveform of each coordinate to the database 181 in the storage device 18.

[0019] The drive control device 12 controls the operation of the drive device 13 according to the signal S1 transmitted from the measurement condition setting unit 111. Specifically, the drive control device 12 transmits a signal S3 for controlling the operation of the drive device 13 to the drive device 13. The drive device 13 moves the measurement probe 14 on the circuit board 2 to be measured according to the signal S3 from the drive control device 12, and designates the position and angle of the measurement probe 14. As the drive device 13, for example, a four-axis scanner that moves and rotates the measurement probe 14 in the XYZ-axis directions can be used. The circuit board 2 to be measured is installed on the stage of the four-axis scanner. Note that the drive device 13 is configured to be rotatable, for example, such that the direction of the loop provided at the tip of the measurement probe 14 follows at least two directions orthogonal to each other, but is not limited thereto. The drive device 13 may be configured to be replaceable, for example, such that the direction of the loop provided at the tip of the measurement probe 14 follows at least two directions orthogonal to each other.

[0020] The measurement probe 14 is an electromagnetic field probe that measures the electromagnetic field strength generated in the circuit board 2 to be measured. The measurement probe 14 supplies a signal S4 corresponding to the measured electromagnetic field strength to the amplifier 15. The measurement probe 14 is provided, for example, at the tip of the driving device 13, that is, on the side of the circuit board 2 to be measured. When a loop probe for magnetic field measurement is used as the measurement probe 14, the noise measurement device 1 according to the embodiment can obtain a plurality of magnetic field strength distributions and current distributions corresponding to a plurality of measurement conditions from the measurement data obtained by measuring the magnetic field strength distribution once, without remeasurement. Here, the measurement of the magnetic field strength distribution once includes the measurement of the magnetic field strength distribution in each of two mutually perpendicular directions such as the X-axis and the Y-axis.

[0021] Note that the measurement probe 14 is not limited to a magnetic field probe using a loop probe, and a directional electric field probe can also be used. Since a general electric field probe has no directivity, it is not possible to measure vectors on the X-axis and Y-axis respectively as in the noise measurement process according to the present embodiment. However, by using a photoelectric field sensor with uniaxial directivity, the electric field strength and the electric flux vector can be calculated based on the same process as the noise measurement process according to the present embodiment. Therefore, according to the technology according to the present embodiment, a map showing the electric field strength distribution and / or the electric flux vector can also be displayed. In this case, the noise measurement device 1 according to the embodiment can obtain a plurality of electric field strength distributions corresponding to a plurality of measurement conditions from the measurement data obtained by measuring the electric field strength distribution once, without remeasurement. Here, the measurement of the electric field strength distribution once includes the measurement of the electric field strength distribution in each of two mutually perpendicular directions such as the X-axis and the Y-axis.

[0022] The amplifier 15 is a signal amplifier that amplifies the signal S4 corresponding to the electromagnetic field strength from the measurement probe 14. The amplifier 15 supplies a signal S5 indicating the amplified electromagnetic field waveform to the channel ch2 of the oscilloscope 16.

[0023] As shown in FIG. 1, the oscilloscope 16 has functions as a trigger detection unit 161 and a waveform acquisition unit 162.

[0024] The oscilloscope 16 has two channels ch1 and ch2. The signal S6 from the reference probe 17 is input to the channel ch1. The input signal S6 is detected as a trigger waveform by the trigger detection unit 161. The signal S5 from the measurement probe 14 amplified by the amplifier 15 is input to the channel ch2. The input signal S5 is detected as an electromagnetic field waveform by the waveform acquisition unit 162.

[0025] The trigger detection unit 161 detects a trigger based on the signal waveform of a reference signal such as a clock signal from the circuit board 2 to be measured, that is, the reference waveform. Specifically, the trigger detection unit 161 acquires a trigger at the rising and / or falling timing of the signal S6 corresponding to the reference waveform of the circuit board 2 to be measured measured by the reference probe 17. The acquired trigger waveform serves as a trigger for synchronizing the waveform detected by the waveform acquisition unit 162. When the circuit board 2 to be measured is the above-mentioned power supply circuit, the trigger detection unit 161 detects a trigger along with the switching operation of the power semiconductor device based on the voltage waveform of the voltage measured at the output end on the power semiconductor side of the drive circuit. Here, the output end on the power semiconductor side of the drive circuit is the switching part in the control IC 27.

[0026] The waveform acquisition unit 162 synchronizes with the trigger acquired by the trigger detection unit 161 and uses the measurement time set by the measurement condition setting unit 111 to acquire the electromagnetic field intensity at each angle from the measurement probe 14 at each of a plurality of measurement points within the measurement scanning range. In other words, the waveform acquisition unit 162 measures the time-series data indicating the electromagnetic field intensity from the circuit board 2 to be measured at the measurement time at each of a plurality of measurement points set in the vicinity of the circuit board 2 to be measured, synchronizing with the trigger detected by the trigger detection unit 161. Further, the waveform acquisition unit 162 sequentially outputs a signal S8 indicating the measurement result, that is, the time-series data of the electromagnetic field waveform synchronized with the trigger, to the measurement control device 11.

[0027] The reference probe 17 is a voltage probe that is electrically connected to the circuit board 2 under measurement and measures a reference signal for controlling the switching operation of the circuit board 2 under measurement. The reference probe 17 supplies a signal S6 corresponding to the measured reference signal to channel ch1 of the oscilloscope 16. When the circuit board 2 under measurement is the above-described power supply circuit, the reference probe 17 is electrically connected to the output end on the power semiconductor side of the drive circuit. In the example shown in FIG. 2, the reference probe 17 is electrically connected to the input end side of the coil 25.

[0028] Note that a current probe can also be used as the reference probe 17. Further, if the installation position is fixed and the reference waveform can be acquired, a non-contact electric field probe or magnetic field probe can also be used. In this case, the reference probe 17 does not have to be electrically connected to the circuit board 2 under measurement.

[0029] Note that in the noise measurement device 1 according to the embodiment, as shown in FIG. 1, the combination of the oscilloscope 16 that realizes the trigger detection unit 161 and the reference probe 17 may be expressed as the trigger detection unit 20.

[0030] Note that the noise measurement device 1 according to the embodiment can also be expressed as having the function as the measurement unit 10 as shown in FIG. 1. Here, as shown in FIG. 1, the measurement unit 10 includes the measurement condition setting unit 111 of the measurement control device 11, the data combining unit 112 of the measurement control device 11, and the waveform acquisition unit 162 of the oscilloscope 16. That is, the measurement unit 10 measures time-series data indicating the electromagnetic field intensity from the circuit board 2 under measurement at a set measurement time in synchronization with the trigger while moving the measurement probe 14 to each of a plurality of measurement points by the drive device 13. Here, the measurement unit 10 is an example of an acquisition unit.

[0031] Note that the combination of the measurement control device 11 that realizes the measurement unit 10, the drive control device 12, the drive device 13, the measurement probe 14, the amplifier 15, and the oscilloscope 16 that realizes the measurement unit 10 may be expressed as the measurement unit.

[0032] The storage device 18 stores a database 181. In the database 181, data in which the measurement position and the time series of the electromagnetic field strength are associated at a plurality of measurement points (data indicated by the signal S9) output from the data combining unit 112 is stored. As the storage device 18, various storage media such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), and a Flash memory can be used.

[0033] The display control device 19 is a device that controls the display of the electromagnetic field strength distribution in the noise measurement device 1. The display control device 19 functions as the noise measurement device 1 according to the embodiment by executing a program (application program) for realizing the display process according to the embodiment. As the display control device 19, for example, information processing devices such as a smartphone, a personal computer (PC), and a tablet PC can be appropriately used.

[0034] As shown in FIG. 1, the display control device 19 has functions as a display condition setting unit 191, an arithmetic unit 192, and a display unit 193.

[0035] The display condition setting unit 191 sets conditions for a specified section and a specified frequency, for example, in response to a user input. Here, the specified section is a section having a time width shorter than the time width of the measurement time. Further, the display condition setting unit 191 can reset at least one of the conditions of the specified section and the specified frequency, for example, at the time after the map display of the electromagnetic field strength distribution. The display condition setting unit 191 is an example of a condition setting unit.

[0036] Based on the time series data of the electromagnetic field strength at each of a plurality of angles at each of a plurality of measurement points stored in the database 181 of the storage device 18, the arithmetic unit 192 outputs the electromagnetic field strength distribution and the current distribution regarding the plurality of measurement points under the conditions of the specified section and the specified frequency set by the display condition setting unit 191.

[0037] Specifically, the calculation unit 192 acquires a signal S10 indicating the time-series data of the electromagnetic field strength of each of a plurality of measurement points from the storage device 18. Therefore, the calculation unit 192 can also be expressed as an example of an acquisition unit. The calculation unit 192 extracts the time-series data of a specified section from the time-series data of the electromagnetic field strength of each of the plurality of measurement points measured by the measurement unit 10. The calculation unit 192 calculates the power spectrum and the phase component by fast Fourier transform from the time-series data of the specified section. The calculation unit 192 acquires the electromagnetic field strength component and the current vector at a specified frequency from the power spectrum and the phase component calculated for each of the plurality of measurement points. The calculation unit 192 outputs the electromagnetic field strength and / or the current vector for the plurality of measurement points under the conditions of the specified section and the specified frequency to the display unit 193.

[0038] Further, when the conditions of the specified section and the specified frequency are reset by the display condition setting unit 191, the calculation unit 192 re-outputs the electromagnetic field strength and the current vector for the plurality of measurement points under the conditions of the reset specified section and the specified frequency.

[0039] Based on the electromagnetic field strength and / or the current vector for the plurality of measurement points under the conditions of the specified section and the specified frequency output by the calculation unit 192, the display unit 193 plots the electromagnetic field strength and / or the current vector according to the position of each of the plurality of measurement points, and generates image data for displaying a map showing the electromagnetic field strength distribution and / or the current distribution. The display unit 193 displays an image showing the map on a display or the like based on the generated image data. The display unit 193 superimposes and displays an image showing the arrangement of the components of the circuit board 2 to be measured on the image showing the map.

[0040] Note that the display control device 19 that realizes the calculation unit 192 may be expressed as a calculation unit. Similarly, the combination of the display control device 19 that realizes the display unit 193, the display I / F 106 described later, and the display 107 described later may be expressed as a display unit.

[0041] Hereinafter, with reference to FIGS. 3 to 27, an example of the operation of the noise measurement device 1 according to the present embodiment will be described. Here, as an example, for a DCDC power supply board as the circuit board 2 to be measured with a size of 64 mm × 40 mm that switches at 750 kHz, the magnetic field distribution measurement at a specified frequency of 100 MHz is performed for (32, 20) points within a range of 2 mm pitch.

[0042] FIG. 3 is a flowchart showing an example of the measurement process according to the embodiment. FIG. 4 is a diagram showing an example of a reference trigger waveform obtained when the DCDC power supply board as the circuit board 2 to be measured is measured by the reference probe 17 in the noise measurement device 1 according to the embodiment. FIG. 5 is a diagram showing an example of a magnetic field intensity waveform at a specified coordinate obtained when the DCDC power supply board as the circuit board 2 to be measured is measured by the measurement probe 14 with the reference probe 17 triggering in the noise measurement device 1 according to the embodiment. In the graphs shown in FIGS. 4 and 5, the vertical axis represents intensity (Level) [V], and the horizontal axis represents time (Time) [μsec]. FIGS. 6 and 7 are diagrams for explaining the acquisition of the voltage waveform of the near magnetic field in the noise measurement process according to the embodiment, respectively.

[0043] The process in FIG. 3 starts with the circuit board 2 to be measured being installed on the stage of the four-axis scanner as the driving device 13 and operating. Also, the reference probe 17 is electrically connected to, for example, the input end side of the coil 25, and it is assumed that the clock waveform of the clock signal can be measured as the reference waveform. Also, it is assumed that the initial position (0, 0) and the end position (32, 20) of the measurement scan range are set. Also, it is assumed that the voltage waveform of the near magnetic field is measured for each of the two angles in the X direction and the Y direction.

[0044] The trigger detection unit 161 acquires a reference waveform (S101) and sets a measurement time of one cycle or more of the reference waveform under the conditions instructed by the measurement condition setting unit 111 (S102). Specifically, the trigger detection unit 161 takes a trigger at the rising or falling timing of the clock signal by channel ch1 of the oscilloscope 16, and sets the measurement time to a time including one cycle or more of the clock waveform as the reference waveform shown in FIG. 4.

[0045] The measurement condition setting unit 111 instructs the drive device 13 to move the measurement probe 14 to the initial position (0, 0) of the designated coordinates on the circuit board 2 to be measured (S103). Further, the measurement condition setting unit 111 sets trigger conditions such as a threshold value for the trigger detection unit 161 of the oscilloscope 16, and sets the measurement time and the like for the waveform acquisition unit 162. In channel ch2 of the oscilloscope 16, the voltage waveform from the measurement probe 14 is held by the trigger set by the trigger detection unit 161, and the time series of the voltage waveform of the near electromagnetic field at the measurement time as shown in FIG. 5 is acquired (S104). The waveform acquisition unit 162 transmits the acquired time series data of the near electromagnetic field to the data combining unit 112. At this time, the data combining unit 112 acquires the current position coordinates from the drive control device 12. Thereby, the time series data can be made into data of a file name (0, 0.csv) associated with the coordinates of the measurement location by the data combining unit 112. The data combining unit 112 stores the time series data indicating the electromagnetic field waveforms of each coordinate in the designated folder of the database 181 of the storage device 18 (S105).

[0046] When the full-range measurement is not completed (S106: No), the measurement control device 11 issues a command to release the hold of the voltage waveform to the oscilloscope 16 (S107), and issues a command to move the measurement probe 14 to the next specified coordinates (e.g., 1, 0) to the drive control device 12 (S103). Also at the next coordinates, the voltage waveform is acquired as described above (S104), and the acquired time-series data of the near electromagnetic field is stored in the specified folder of the database 181 with, for example, the file name (1, 0.csv) (S105). The same process is executed. Similarly, after measuring up to the end coordinates of the X coordinate such as (2, 0), (3, 0), (4, 0) … (32, 0), the Y coordinate is moved, the X coordinate is returned to the initial position, and measurements are performed at each measurement point of (0, 1), (1, 1) … (32, 1). Similarly, up to the end coordinates of the Y coordinate (32, 20), the voltage waveform is repeatedly acquired as (0, 20), (1, 20) … (32, 20), and scanning of all the set ranges on the circuit board 2 to be measured is executed.

[0047] After the data storage at the end position (32, 20.csv) is completed and waveforms of all the set ranges are acquired (S106: Yes), it is displayed that the measurement has been completed without problems, and the process of FIG. 3 for measuring the magnetic flux φ ends.

[0048] In the process of FIG. 3, the processes of S103 to S107 are executed for each of the X direction and the Y direction. For example, as shown in FIG. 6, in the measurement of the magnetic flux φx in the X direction, it is assumed that the loop of the measurement probe 14 is rotated by an angle of 90° with respect to the front. At this time, the voltage waveform Vx obtained by time-differentiating the magnetic flux φx in the left-right direction with respect to the front, that is, the X direction, is acquired and stored. Similarly, in the measurement of the magnetic flux φy in the Y direction, it is assumed that the loop of the measurement probe 14 is rotated by an angle of 0° with respect to the front, as shown in FIG. 7, for example. At this time, the voltage waveform Vy obtained by time-differentiating the magnetic flux φy in the front-rear direction with respect to the front, that is, the Y direction, is acquired and stored. Therefore, in the process of S106, in response to the completion of the measurement of the magnetic flux φ in each of the two directions of the X direction and the Y direction, it is displayed that the measurement has been completed without problems, and the process of FIG. 3 for measuring the magnetic flux φ ends.

[0049] Note that the processes of S103 to S107 may be executed not only in the X direction and the Y direction, but also for each of two mutually perpendicular directions other than the X direction and the Y direction.

[0050] Note that in this embodiment, the case where the measurement probe 14 is rotated by the driving device 13, or the measurement probe 14 is replaced and the attachment angle to the driving device 13 is changed, and the electromagnetic field intensity is measured in synchronization with the trigger for each of two mutually perpendicular directions is illustrated, but it is not limited thereto. The measurement probe 14 may be configured as a probe array in which a plurality of probes are arranged. In the measurement probe 14, the plurality of probes may be arranged in one dimension or two dimensions. Also, in the measurement probe 14, the directions of the loops of the plurality of probes may be in one direction or in two mutually perpendicular directions. When the directions of the loops of the plurality of probes are in one direction, the measurement probe 14 may be rotated by the driving device 13, or the measurement probe 14 may be replaced and the attachment angle to the driving device 13 may be changed. Also, when the directions of the loops of the plurality of probes are in two mutually perpendicular directions, the movement by the driving device 13 may be controlled according to the direction of the loop of each probe. In these cases, the measurement unit 10 may measure time-series data indicating the electromagnetic field intensity from the circuit board 2 to be measured at the set measurement time in synchronization with the trigger at each of the plurality of measurement points by switching each of the plurality of probes at the positions corresponding to each of the plurality of measurement points in synchronization with the detected trigger.

[0051] FIG. 8 is a flowchart showing an example of the display process according to the embodiment. The flow of FIG. 8 is executed after the measurement of the magnetic fluxes φ in the X direction and the Y direction is completed according to the flow of FIG. 3.

[0052] The calculation unit 192 designates a folder in the database 181 in which measurement results associated with the coordinates of each of a plurality of measurement positions are stored (S201). In the folder in the database 181, measurement data associated with each of the plurality of measurement coordinates is stored. Therefore, the calculation unit 192 can read out the measurement data of the magnetic fluxes φx and φy in the X direction and the Y direction of the designated coordinates from the database 181 by designating the coordinates.

[0053] The display condition setting unit 191 sets a designated section and a designated frequency, for example, in response to a user input (S202). Specifically, the display condition setting unit 191 sets the start time and the end time of the time period for which extraction is desired as the designated section based on the reference waveform acquired by the reference probe 17. In the example shown in FIG. 4, section A (0 μsec to 0.1 μsec) and section B (0.6 μsec to 0.7 μsec) are set as the designated sections to be extracted. Also, the display condition setting unit 191 sets the frequency of the magnetic field distribution for which extraction is desired, such as 100 MHz, as the designated frequency.

[0054] After setting the designated section and the designated frequency, the calculation unit 192 sequentially calls the measurement data of the magnetic field strength waveforms in the X direction and the Y direction respectively associated with the coordinates from the initial position data (0,0.csv) (S203). The calculation unit 192 extracts the voltage waveform of the designated section from each of the called waveform data (S204). FIG. 9 is a diagram showing an example of the magnetic field strength waveform from which section A in FIG. 5 has been extracted. FIG. 10 is a diagram showing an example of the magnetic field strength waveform from which section B in FIG. 5 has been extracted. In the graphs shown in FIGS. 9 and 10, the vertical axis indicates the intensity (Level) [V], and the horizontal axis indicates the time (Time) [μsec]. For example, when section A is the designated section, the calculation unit 192 extracts the waveform data of section A as shown in FIG. 9 from the waveform data shown in FIG. 5. For example, when section B is the designated section, the calculation unit 192 extracts the waveform data of section B as shown in FIG. 10 from the waveform data shown in FIG. 5.

[0055] The calculation unit 192 performs FFT conversion on the voltage waveform of the extracted specified section, and extracts the intensity component and phase component of the specified frequency (S205). Specifically, the calculation unit 192 performs FFT conversion on the voltage waveform of the extracted specified section, and generates information indicating the power spectrum (magnetic field spectrum) and the phase component on the frequency axis. In other words, the calculation unit 192 converts the voltage waveform of the extracted specified section into information indicating the power spectrum (magnetic field spectrum) and the phase component on the frequency axis. Then, the calculation unit 192 extracts the intensity D corresponding to the specified frequency from the magnetic field spectrum as a numerical value of power [mW] (or [μW]) converted from [dBm]. In addition, the calculation unit 192 extracts the phase θ as a numerical value in [°] from the information indicating the phase component on the frequency axis.

[0056] FIG. 11 is a diagram showing an example of a magnetic field spectrum obtained by performing FFT processing on the magnetic field intensity waveform related to section A in FIG. 9. FIG. 12 is a diagram showing an example of a magnetic field spectrum obtained by performing FFT processing on the magnetic field intensity waveform related to section B in FIG. 10. In the graphs shown in FIGS. 11 and 12, the vertical axis indicates the intensity [dBm], and the horizontal axis indicates the frequency [MHz]. For example, when section A is the specified section, the calculation unit 192 generates the magnetic field spectrum shown in FIG. 11 from the voltage waveform on the time axis shown in FIG. 9. For example, when section B is the specified section, the calculation unit 192 generates the magnetic field spectrum shown in FIG. 12 from the voltage waveform on the time axis shown in FIG. 10.

[0057] FIG. 13 is a diagram showing an example of the phase component of the magnetic field obtained by performing FFT processing on the magnetic field intensity waveform related to section A in FIG. 9. FIG. 14 is a diagram showing an example of the phase component of the magnetic field obtained by performing FFT processing on the magnetic field intensity waveform related to section B in FIG. 10. In the graphs shown in FIGS. 13 and 14, the vertical axis indicates the phase [deg.], and the horizontal axis indicates the frequency [MHz]. For example, when section A is the specified section, the calculation unit 192 converts the voltage waveform on the time axis shown in FIG. 9 into the phase information on the frequency axis shown in FIG. 13. For example, when section B is the specified section, the calculation unit 192 converts the voltage waveform on the time axis shown in FIG. 10 into the phase information on the frequency axis shown in FIG. 14.

[0058] For each of the X-axis and the Y-axis, the calculation unit 192 calculates the magnetic field strength distribution from the intensity components of the extracted specified frequency (S206). The calculation of the magnetic field strength distribution will be described later with reference to Equation (7).

[0059] For each of the X-axis and the Y-axis, the calculation unit 192 calculates vectors in each direction from the extracted intensity components and phase components (S207). FIG. 15 is a diagram showing an example of the result of calculation using the cosine function for the phase component of the magnetic field related to section A in FIG. 13. FIG. 16 is a diagram showing an example of the result of calculation using the cosine function for the phase component of the magnetic field related to section B in FIG. 14. In the graphs shown in FIGS. 15 and 16, the vertical axis represents the value of cosθ of the phase [-], and the horizontal axis represents the frequency [MHz]. Specifically, the calculation unit 192 converts the phase θ extracted from the phase information on the frequency axis related to section A shown in FIG. 13 to a value from -1 to +1 using the cosine function as shown in FIG. 15. Further, the calculation unit 192 converts the phase θ extracted from the phase information on the frequency axis related to section B shown in FIG. 14 to a value from -1 to +1 using the cosine function as shown in FIG. 16.

[0060] Here, assuming that the value of the phase θ extracted from the phase information on the frequency axis converted using the cosine function is the coefficient k, the direction of the arrow of the vector on each of the X-axis and Y-axis corresponds to the sign of the coefficient k. When displaying the vector, it is only necessary to be able to determine the direction of the arrow of the vector. For this reason, based on the calculation results shown in FIGS. 15 and 16 respectively, the arithmetic unit 192 sets the value of the coefficient k corresponding to each frequency to “+1” or “-1”. FIG. 17 is a diagram showing an example of the coefficient k calculated from the calculation result related to the section A in FIG. 15. FIG. 18 is a diagram showing an example of the coefficient k calculated from the calculation result related to the section B in FIG. 16. In the graphs shown in FIGS. 17 and 18, the vertical axis represents the value of the coefficient k [-], and the horizontal axis represents the frequency [MHz]. Specifically, as shown in FIGS. 17 and 18, when the value of cosθ is less than 0 and not less than -1, the arithmetic unit 192 sets all the coefficients k to “-1”. On the other hand, when cosθ is not less than 0 and not more than 1, the arithmetic unit 192 sets all the coefficients k to “+1” as shown in FIGS. 17 and 18. Incidentally, when the value of cosθ is 0, the coefficient k may be set to “-1”.

[0061] The arithmetic unit 192 extracts the coefficient k corresponding to the section and the specified frequency (100 MHz in this embodiment) from FIG. 17 or FIG. 18, and multiplies it by the intensity D of the specified frequency extracted in the process of S205 to calculate kD. As a result, the measurement results become vectors of the magnetic fluxes φx and φy having directivity. Therefore, the arithmetic unit 192 can calculate a vector of +Dx(m, n) or -Dx(m, n) at the target coordinates (m, n) from the measurement result in the X direction. Similarly, the arithmetic unit 192 can calculate a vector of +Dy(m, n) or -Dy(m, n) at the target coordinates (m, n) from the measurement result in the Y direction.

[0062] In this embodiment, an example is given where the direction of the arrow of the vector on each of the X-axis and Y-axis is determined according to the value of the phase θ extracted from the phase information of the frequency axis converted using the cosine function, that is, according to the sign of the coefficient k. However, the present invention is not limited to this. The direction of the arrow of the vector on each of the X-axis and Y-axis may be determined according to whether a predetermined duty ratio is satisfied with respect to the phase θ extracted from the phase information of the frequency axis, for example.

[0063] Thereafter, the calculation unit 192 synthesizes the vectors in each direction calculated in the process of S207 to calculate magnetic flux vectors φx and φy (S208). FIG. 19 is a diagram for explaining a method of calculating the magnetic flux vectors φx and φy of the target coordinates (m, n). As shown in FIG. 19, the calculation unit 192 calculates the magnetic flux vector φx of the magnetic flux X component at the target coordinates (m, n) by the following equation (1). Similarly, as shown in FIG. 19, the calculation unit 192 calculates the magnetic flux vector φy of the magnetic flux Y component at the target coordinates (m, n) by the following equation (2). In this way, the two magnetic flux vectors φx and φy are vectors having magnitudes corresponding to the intensity D and directions corresponding to the phase θ, respectively. However, the coefficient kx and the coefficient ky are “+1” or “−1”, respectively. The magnetic flux vector φxy in the X-Y plane of the target coordinates (m, n) in this case is represented by equation (3). Here, the magnetic flux vector φxy in the X-Y plane is an example of a plane vector.

[0064]

Equation

[0065] Further, the arithmetic unit 192 calculates current vectors Ix and Iy from the orthogonal components of the magnetic flux vectors φx and φy calculated in the process of S208 (S209). FIG. 20 is a diagram for explaining a method of calculating the current vectors Ix and Iy at target coordinates (m, n). By calculating the orthogonal components for each of the magnetic flux vectors φx and φy, it becomes possible to indicate the flow of current. As shown in FIG. 20, the arithmetic unit 192 calculates the current vector Ix in the X direction at the target coordinates (m, n) by the following equation (4). Similarly, as shown in FIG. 20, the arithmetic unit 192 calculates the current vector Iy in the Y direction at the target coordinates (m, n) by the following equation (5). However, the coefficient kx and the coefficient ky are “+1” or “-1”, respectively. The current vector Ixy in the X-Y plane of the target coordinates (m, n) in this case is represented by equation (6). Here, the current vector Ixy in the X-Y plane is an example of a plane vector.

[0066]

Number

[0067] Thereafter, based on the current vector Ixy and / or the intensity Dxy calculated for the target coordinates (m, n), the display unit 193 displays or updates a map showing the current distribution and / or the magnetic field intensity distribution (S210). The display of the map showing the current distribution and / or the magnetic field intensity distribution will be described later.

[0068] When the display of the entire range is not completed (S211: No), the above-described processes of S203 to S210 are executed for the electromagnetic field measurement data of the next target coordinates. Note that the above-described processes of S203 to S210 are executed in the order of (0,0), (1,0), (2,0), (3,0), (4,0)…(32,0)…(0,1), (1,1)…(32,1)…(0,20), (1,20)…(32,20) up to the data (32, 20.csv) at the end position, in the same manner as during measurement. Note that the processing order is not limited to this and can be arbitrarily set.

[0069] On the other hand, when the display of the entire range is completed (S211: Yes), the process of FIG. 8 ends.

[0070] Here, a map showing the current distribution that can be displayed in S210 of the flow of FIG. 8 will be described. FIG. 21 is a diagram showing an example of a map of the current distribution at 100 MHz in section A, which is displayed in the display process according to the embodiment. FIG. 22 is a diagram showing an example of a map of the current distribution at 100 MHz in section B, which is displayed in the display process according to the embodiment. When the display of the entire range is completed, that is, when the display for the last target coordinate among the (32, 20) points is performed, a display screen including the maps of the current distribution as shown in FIGS. 21 and 22 respectively is displayed. In the map of the current distribution, the current vector Ixy calculated for each coordinate position is shown at each coordinate position.

[0071] Note that in the display screen, as shown in FIGS. 21 and 22 respectively, the arrangement of each element on the circuit board 2 to be measured as shown in FIG. 2, for example, may be superimposed and displayed on the map.

[0072] Note that the display including the maps as shown in FIGS. 21 and 22 may be sequentially displayed for the data at each position as described above, or may be collectively displayed after the mapping of the entire range is completed.

[0073] Here, a map showing the magnetic field strength distribution that can be displayed in S210 of the flow of FIG. 8 will be described. FIG. 23 is a diagram showing an example of a map of the magnetic field strength distribution at 100 MHz in section A, which is displayed in the display process according to the embodiment. FIG. 24 is a diagram showing an example of a map of the magnetic field strength distribution at 100 MHz in section B, which is displayed in the display process according to the embodiment. When the display unit 193 displays a map showing the magnetic field strength distribution, for the frequency spectrum, the intensity D corresponding to the specified frequency is used as a numerical value. The calculation unit 192 calculates the intensity Dxy in the X - Y plane of the target coordinate (m, n) using the following formula (7) based on the intensity Dx(m, n) obtained from the measurement result in the X direction and the intensity Dy(m, n) obtained from the measurement result in the Y direction.

[0074]

Number

[0075] Further, the calculation unit 192 converts the unit of Dxy(m,n) calculated by the formula (7) from the linear notation values of [mW] or [μW] to [dBm], and then outputs it as the intensity of the coordinates (m,n). Then, the display unit 193 maps the intensities of the converted respective coordinates (m,n) and displays a display screen including a map showing the magnetic field intensity distribution. In the map showing the magnetic field intensity distribution, the intensities of each coordinate are displayed in a color scheme associated with the intensity. As an example, when the intensity is strong, a warm color scheme such as red is used; when the intensity is medium, a yellow or green color scheme is used; when the intensity is weak, a cool color scheme such as blue or dark blue is used, so that the user can intuitively grasp the intensity distribution. Note that this color scheme according to the intensity can be reset again after all the intensities in the map showing the magnetic field intensity distribution are displayed. In addition, in the said display screen, the maximum value and the minimum value in the map may be displayed as numerical values on the side of the map showing the magnetic field intensity distribution as a reference when resetting the color scheme.

[0076] Here, a map showing the current vector or magnetic flux vector that can be displayed in S210 of the flow in FIG. 8 and the magnetic field strength distribution will be described. Here, the map showing the current vector can be treated as the current distribution itself. Also, the map showing the magnetic flux vector can be treated as a display directly related to the current distribution from the viewpoint that the magnetic flux vector is generated orthogonally from the current. FIG. 25 is a diagram showing an example of a map obtained by synthesizing the magnetic field strength distribution and the current distribution at 100 MHz in section A, which is displayed in the display process according to the embodiment. FIG. 26 is a diagram showing an example of a map obtained by synthesizing the magnetic field strength distribution and the current distribution at 100 MHz in section B, which is displayed in the display process according to the embodiment. As shown in FIGS. 25 and 26, the display unit 193 may display the magnetic field strength distribution and the current distribution on the same map. Alternatively, from the viewpoint of ensuring readability, etc., as shown in FIGS. 21 to 24, the display unit 193 may display the magnetic field strength distribution and the current distribution on different maps. The display unit 193 can change the distribution to be displayed on the map, for example, in response to a user's input operation.

[0077] Here, as shown in FIGS. 21, 22, 25, and 26, the current distribution based on the voltage waveform extracted in the specified section of section A is different from the current distribution based on the voltage waveform extracted in the specified section of section B. Also, as shown in FIGS. 23 to 26, the magnetic field strength distribution based on the voltage waveform extracted in the specified section of section A is different from the magnetic field strength distribution based on the voltage waveform extracted in the specified section of section B. These indicate that section A shows the section at the rising edge of the switching signal, section B is the section at the falling edge of the switching signal, and the results of the magnetic field strength distribution and the current distribution in different specified sections of the same specified frequency are obtained. That is, according to the noise measurement device 1 according to the embodiment, a plurality of results can be displayed according to conditions from a single measurement data.

[0078] In this way, the noise measurement process according to this embodiment can output the near electromagnetic field distribution and current distribution generated from the measured circuit board 2 that operates with switching, under the conditions of a plurality of specified intervals and specified frequencies, without re-measurement. Also, since the near electromagnetic field measurement results under a plurality of conditions can be obtained, it is possible to determine the noise generation time points during the switching operation, such as at the rising edge or falling edge, without re-measurement.

[0079] Conventionally, in the measurement of the near electromagnetic field of a circuit board, it has been difficult to measure in synchronization with the rising or falling of the switching frequency of the circuit board. On the other hand, the noise measurement process according to this embodiment measures the electromagnetic field intensity with a measurement time having a time width of one wavelength or more of the reference signal, in synchronization with the trigger detected based on the signal waveform of the reference signal for the switching operation input to the measured circuit board 2. Therefore, in the near electromagnetic field measurement of the measured circuit board 2 for identifying the noise source and grasping the conduction state, the number of measurements can be reduced. The reduction in the number of measurements contributes to suppressing the decrease in repeatability and reproducibility due to human error or the like.

[0080] Also, in the noise measurement process according to this embodiment, since a current vector indicating the current direction can be output without re-measurement, the flow of noise can be easily grasped. Furthermore, even if only the intensity of the magnetic flux is vectorially displayed, it can only represent the range from 0° to 90°. However, in the noise measurement process according to this embodiment, by giving a sign component to the magnetic flux intensity of each of the X component and the Y component, vector display for 360°, that is, for all directions with respect to the X-Y plane is possible. By obtaining the vector display of the in-plane current direction, more detailed identification of the noise source and grasping of the conduction state are realized.

[0081] Here, the hardware configurations of the respective devices (measurement control device 11, oscilloscope 16, storage device 18, and display control device 19) of the noise measurement device 1 according to each of the above-described embodiments will be described. FIG. 27 is a block diagram showing an example of the hardware configuration of each device of the noise measurement device 1 according to the embodiment. The measurement control device 11, the oscilloscope 16, the storage device 18, and the display control device 19 are realized, for example, by an information processing device 100 having a hardware configuration as shown in FIG. 27.

[0082] The information processing device 100 has, for example, a hardware configuration similar to that of a normal computer. That is, the information processing device 100 includes a processor 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, a storage device 104, and a network interface (I / F) 105. The processor 101, the ROM 102, the RAM 103, the storage device 104, and the network I / F 105 are communicably connected via a bus.

[0083] The processor 101 controls the overall operation of each device. As the processor 101, for example, a CPU (Central Processing Unit) is used, but other processors such as a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), and an FPGA (Field Programmable Gate Array) may be used.

[0084] The processor 101 loads the program stored in the storage device 104 into the RAM 103 and executes it to realize the functions as each part illustrated in FIG. 1. In the ROM 102, a start program for loading the operating system startup program from the storage device 104 into the RAM 103 and the like are stored.

[0085] As the memory device 104, various memory media such as HDD, SSD, and Flash memory can be used. The memory device 104 stores parameters such as an operating system, application programs, data, and thresholds used in each process.

[0086] The network I / F 105 is an interface circuit for communicating with the outside. The network I / F 105 includes a communication circuit for wireless communication or a communication circuit for wired communication corresponding to various communication standards such as BLE (Bluetooth (registered trademark) Low Energy), Wi-Fi (registered trademark), Sub-1GHz, IEEE802.15.4, and LTE Cat-1 of each device.

[0087] The measurement control device 11, the oscilloscope 16, and the display control device 19 further include an input / output I / F 108 and an input device 109. The input device 109 is communicably connected to the processor 101, the ROM 102, the RAM 103, the memory device 104, and the network I / F 105 via the input / output I / F 108. The input / output I / F 108 outputs the information acquired by the input device 109 to the bus according to the control of the processor 101. As the input / output I / F 108, a general-purpose I / F such as USB, GP-IB, Ethernet (registered trademark), or a bus of a unique I / F for machine control can be appropriately used. The input device 109 of the measurement control device 11 is a measurement system including the above-described drive control device 12, drive device 13, measurement probe 14, amplifier 15, oscilloscope 16, and reference probe 17. In addition, the input device 109 of the measurement control device 11, the oscilloscope 16, and the display control device 19 includes an operation unit that receives user operations. As the operation unit, various input devices such as a keyboard, a mouse, a touch panel, buttons, levers, and switches can be appropriately used.

[0088] The display control device 19 further includes a display I / F 106 and a display 107. The display I / F 106 is communicably connected via a bus to the processor 101, the ROM 102, the RAM 103, the storage device 104, the network I / F 105, and the input / output I / F 108. The display I / F 106 supplies an image signal to the display 107 under the control of the processor 101. The display 107 is a display device such as a liquid crystal display or an organic EL display that displays information (display screens 510, 520) according to the supplied image signal.

[0089] Note that at least two of the measurement control device 11, the oscilloscope 16, the storage device 18, and the display control device 19 according to the embodiment may be configured as one device. In other words, the noise measurement device 1 according to the embodiment may be configured by one device or may be configured as a noise measurement system including a plurality of devices.

[0090] Note that the measurement control device 11, the oscilloscope 16, the storage device 18, and the display control device 19 according to the embodiment may be respectively connected to a network such as the Internet and may be connected to each other via the network.

[0091] The program executed by the information processing device 100 according to the embodiment is provided by being recorded on a computer-readable recording medium such as a CD-ROM, a flexible disk (FD), a CD-R, a DVD, a Flash memory, etc. in an installable format or an executable format file.

[0092] Alternatively, the program executed by the information processing apparatus 100 according to the embodiment may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. Alternatively, the program executed by the information processing apparatus 100 according to the embodiment may be configured to be provided or distributed via a network such as the Internet. Alternatively, the program according to the embodiment may be configured to be provided by being pre - incorporated into a ROM 102 or the like.

[0093] Note that the program for causing the information processing apparatus 100 to function as the measurement control apparatus 11 has a module configuration including a measurement condition setting unit 111 and a data combining unit 112. Also, the program for causing the information processing apparatus 100 to function as the oscilloscope 16 has a module configuration including a trigger detection unit 161 and a waveform acquisition unit 162. Also, the program for causing the information processing apparatus 100 to function as the display control apparatus 19 has a module configuration including a display condition setting unit 191, an arithmetic unit 192, and a display unit 193. These programs are an example of the noise measurement program according to the embodiment.

[0094] As actual hardware, the information processing apparatus 100 causes the processor 101 to read and execute a program from a storage medium such as the storage device 104, whereby each module is loaded onto the main storage device (RAM 103). Thereby, the processor 101 of the measurement control apparatus 11 functions as the measurement condition setting unit 111 and the data combining unit 112. Also, the processor 101 of the oscilloscope 16 functions as the trigger detection unit 161 and the waveform acquisition unit 162. Also, the processor 101 of the display control apparatus 19 functions as the display condition setting unit 191, the arithmetic unit 192, and the display unit 193. Note that part or all of the functional configuration of the information processing apparatus 100 may be realized by hardware.

[0095] According to at least one of the embodiments described above, the number of measurements in the measurement of the near - electromagnetic field of the circuit board can be reduced.

[0096] Although some embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

Explanation of Reference Numerals

[0097] 1 Noise measurement device 10 Measurement unit 100 Information processing device 101 Processor 102 ROM 103 RAM 104 Storage device 105 Network I / F 108 Input / output I / F 109 Input device 106 Display I / F 107 Display 11 Measurement control device 111 Measurement condition setting unit 112 Data combining unit 12 Drive control device 13 Driving device 14 Measurement probe 15 Amplifier 16 Oscilloscope 161 Trigger detection unit 162 Waveform acquisition unit 17 Reference probe 18 Storage device 181 Database 19 Display control device 191 Display condition setting unit (condition setting unit) 192 Arithmetic unit 193 Display unit 2 Circuit board under test

Claims

1. At each of a plurality of measurement points set in the vicinity of the circuit under test, in synchronization with a trigger detected based on the signal waveform of the reference signal input to the circuit under test that switches according to the reference signal, acquiring time-series data indicating the electromagnetic field intensity from the circuit under test measured with a measurement time having a time width of one wavelength or more of the reference signal; extracting time-series data of a specified section specified with a time width shorter than the time width of the measurement time from the acquired time-series data, calculating the electromagnetic field intensity and phase component at a specified frequency specified for each of the plurality of measurement points based on the time-series data of the specified section, and outputting a plane vector corresponding to the electromagnetic field intensity and the phase component for the plurality of measurement points under the conditions of the specified section and the specified frequency; causing a computer to execute; Calculating the electromagnetic field intensity and phase component at a specified frequency specified for each of the plurality of measurement points based on the time-series data of the specified section includes calculating a power spectrum by fast Fourier transform from the time-series data of the specified section, and respectively obtaining the electromagnetic field intensity and the phase component at the specified frequency from the calculated power spectrum for each of the plurality of measurement points. Noise measurement program.

2. The noise measurement program according to claim 1, including calculating the electromagnetic field intensity and the phase component at the specified frequency that are calculated in two directions orthogonal to each other, and calculating the plane vector based on two magnetic flux vectors having a magnitude corresponding to the electromagnetic field intensity and a direction corresponding to the phase component.

3. The noise measurement program according to claim 2, including calculating a current vector based on the orthogonal components of each of the two magnetic flux vectors.

4. The noise measurement program according to claim 2 or claim 3, wherein the directions of the two magnetic flux vectors are determined according to a value obtained by applying a cosine function to the phase component or the duty ratio of the phase component.

5. The noise measurement program according to any one of claims 1 to 4, including outputting a plane vector for the plurality of measurement points under the reset conditions based on the time-series data of each of the plurality of measurement points when at least one of the conditions of the specified section and the specified frequency is reset.

6. In each of the plurality of measurement points, synchronously with the detected trigger, measuring time-series data indicating the electromagnetic field strength from the circuit under measurement at a measurement time having a time width of one wavelength or more of the reference signal for each of two mutually orthogonal directions. The noise measurement program according to any one of claims 1 to 5.

7. Including measuring time-series data for each of the plurality of measurement points by switching each of the plurality of probes at positions corresponding to each of the plurality of measurement points synchronously with the detected trigger. The noise measurement program according to any one of claims 1 to 5.

8. At each of a plurality of measurement points set in the vicinity of the circuit under measurement, synchronously with a trigger detected based on the signal waveform of the reference signal input to the circuit under measurement that switches according to the reference signal, obtaining time-series data indicating the electromagnetic field strength from the circuit under measurement measured at a measurement time having a time width of one wavelength or more of the reference signal; extracting time-series data of a specified section specified by a time width shorter than the time width of the measurement time from the obtained time-series data, calculating the electromagnetic field strength and phase component at a specified frequency specified for each of the plurality of measurement points based on the time-series data of the specified section, and outputting a plane vector corresponding to the electromagnetic field strength and the phase component for the plurality of measurement points under the conditions of the specified section and the specified frequency; including calculating the electromagnetic field strength and phase component at a specified frequency specified for each of the plurality of measurement points based on the time-series data of the specified section includes calculating a power spectrum by fast Fourier transform from the time-series data of the specified section, and respectively obtaining the electromagnetic field strength and the phase component at the specified frequency from the calculated power spectrum for each of the plurality of measurement points. Noise measurement method.

9. An acquisition unit that, at each of a plurality of measurement points set in the vicinity of the circuit under measurement, synchronously with a trigger detected based on the signal waveform of the reference signal input to the circuit under measurement that switches according to the reference signal, obtains time-series data indicating the electromagnetic field strength from the circuit under measurement measured at a measurement time having a time width of one wavelength or more of the reference signal; From the obtained time-series data, extract time-series data of a specified section specified by a time width shorter than the time width of the measurement time, calculate the electromagnetic field strength and phase components at a specified frequency specified for each of the plurality of measurement points based on the time-series data of the specified section, and output a plane vector corresponding to the electromagnetic field strength and the phase components for the plurality of measurement points under the conditions of the specified section and the specified frequency. An arithmetic unit Comprising Calculating the electromagnetic field strength and phase components at a specified frequency specified for each of the plurality of measurement points based on the time-series data of the specified section includes calculating a power spectrum from the time-series data of the specified section by fast Fourier transform, and obtaining the electromagnetic field strength and the phase components at the specified frequency from the calculated power spectrum for each of the plurality of measurement points, respectively. Noise measuring device.

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