JP2020051920A - Radiated emissions measuring device - Google Patents

Abstract

To provide a radiated emissions measuring device with which it is possible to suppress the tendency of total measurement time of radiated emissions to become extended while suppressing a decrease in the accuracy of detecting a maximum electric field intensity position due to the overlooking of a long-period noise.SOLUTION: Provided is a radiated emissions measuring device for applying a median filter to the electric field intensity distribution formed on a plane enclosing the radiation source of radiated emissions and detecting a maximum electric field intensity position on the basis of the electric field intensity distribution after the application of the median filter. The radiated emissions measuring device includes a control device, the control device accepting a first permissible value with regard to first probability and the occurrence cycle of radiated emissions, calculating second probability as a second permissible value for the case where the first probability is the first permissible value, on the basis of a first formula that correlates second probability and the first probability, and the first permissible value, and calculating a sampling time for the case where the second probability is the second permissible value, on the basis of a second formula that correlates the sampling time, the second probability and the occurrence cycle, and the calculated second permissible value.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a radiated emission measuring device.

  2. Description of the Related Art Conventionally, a radiated emission test using a radiated emission measurement device for measuring a radiated emission is performed. A radiated disturbance is an electromagnetic wave radiated from a radiation source such as an electronic device. In the radiated disturbance test, the electric field strength of the radiated disturbance is measured at a maximum electric field strength position for a certain period of time. Then, in the radiated emission measurement test, it is confirmed whether or not the measured electric field strength is equal to or less than an allowable value of an internationally defined standard. Here, the maximum electric field intensity position is a position where the electric field intensity (electric field intensity) of the radiated disturbance wave to be measured is maximum.

  In such a radiated emission test, it is necessary to detect the maximum electric field intensity position for each frequency in the frequency band of 30 to 1000 MHz. For this reason, in the radiated emission measurement test, a spectrum analyzer capable of measuring a spectrum in a wide band is used.

  As an example of a spectrum analyzer capable of measuring a spectrum in a wide band, a general sweep type spectrum analyzer (for example, a spectrum analyzer of a superheterodyne system) is given. A general sweep type spectrum analyzer measures a frequency spectrum while sweeping a measurable frequency in a predetermined resolution bandwidth at every predetermined sampling time (or dwell time). Therefore, in the case where a radiated emission of a frequency other than the frequency occurs while sampling a certain frequency, the spectrum analyzer cannot capture the radiated emission.

  On the other hand, as an example of a spectrum analyzer capable of measuring a spectrum in a wide band, a spectrum analyzer of an FFT (Fast Fourier Transform) system can be given. The FFT spectrum analyzer does not perform sampling during the FFT processing. For this reason, the spectrum analyzer cannot capture the radiated disturbance generated during the FFT processing. Here, the FFT-type spectrum analyzer is a spectrum analyzer that acquires a time waveform of a sampling time, performs FFT processing on the acquired time waveform, and obtains a frequency spectrum.

  As described above, when the generation period of the radiated emission exceeds the sampling time of the spectrum analyzer, the capture rate of the radiated emission is less than 100%. Therefore, in this case, the electric field intensity distribution obtained by the measurement by the spectrum analyzer includes the measurement points at which the radiated interference waves can be captured and the measurement points at which the radiated interference waves cannot be captured. As a result, the maximum electric field intensity position cannot be correctly detected from the electric field intensity distribution measured by the spectrum analyzer, and a correct test result may not be obtained. That is, in the radiated emission test, when the electric field strength distribution is used, there is a possibility that a non-compliant product may be missed.

  In order to solve this problem, there has been proposed a method of improving the capture rate of long-period noise by performing long-period noise measurement a plurality of times (see Patent Document 1). Here, the long-period noise is a radiated disturbance wave whose generation period exceeds the sampling time.

JP 2017-181104 A

  However, in such a method, there is a problem that the total measurement time of the radiated disturbance becomes long because the measurement is performed a plurality of times. Here, the total measurement time of the radiated emission is the total measurement time for measuring the radiated emission in the radiated emission test.

  The present invention has been made in view of such circumstances, and the total measurement time of the radiated disturbance becomes longer while suppressing the decrease in the detection accuracy of the maximum electric field strength position due to the miss of the long-period noise. It is an object of the present invention to provide a radiated emission measuring device capable of suppressing noise.

  One aspect of the present invention is to apply a median filter to an electric field intensity distribution formed on a surface surrounding a radiation source of a radiated disturbance, and based on the electric field intensity distribution after applying the median filter, on the surface A radiated emission measuring device that detects a maximum electric field intensity position where the electric field intensity is maximum, comprising a control device, wherein the control device has spike noise remaining in the electric field intensity distribution after applying the median filter. A first expression for accepting a first permissible value for the first probability to be performed and a generation period of the radiated disturbance, and associating a second probability that a long-period noise is not measured with the first probability; Based on the permissible value, the second probability in the case where the first probability is the first permissible value is calculated as a second permissible value, and that of a plurality of measurement points set on the surface The second probability is calculated based on the second expression that associates the sampling time for measuring the radiated disturbance with the second probability and the generation period, and the calculated second allowable value. A radiated emission measuring device for calculating the sampling time in the case of

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that the total measurement time of a radiated disturbance becomes long, suppressing the fall of the detection precision of the maximum electric field intensity position by the oversight of a long period noise.

It is a figure showing an example of composition of radiated emission measuring device 1 concerning an embodiment. FIG. 4 is a diagram illustrating an example of a resolution bandwidth 300 of the measuring device 40 at a certain time T1. FIG. 7 is a diagram illustrating an example of a resolution bandwidth 300 of the measuring device 40 at a time T2 after the time T1. FIG. 9 is a diagram illustrating an example of a resolution bandwidth 300 of the measuring device 40 at a time T3 after the time T2. FIG. 2 is a diagram illustrating an example of a functional configuration of a control device 10 included in the radiated emission measuring device 1. FIG. 5 is a diagram illustrating a plurality of measurement points set on a surface surrounding a radiation source 50. It is a figure which shows an example of the flow of the process in which the radiated emission measuring device 1 detects the maximum electric field intensity position. It is a figure which shows an example of the electric field intensity distribution when the capture rate of a radiated interference wave is less than 100%. It is a figure which illustrates each of nine points contained in image P before applying a median filter. FIG. 10 is a diagram illustrating an example of a result obtained by applying a median filter to the spike noise illustrated in FIG. 9. It is a figure which shows the relative length of each of the moving time Tm1, the sampling time Ts1, and the processing time Td1 with respect to the generation period Tn of the radiated disturbance wave. It is a figure which shows the relative length of each of the movement time Tm2, the sampling time Ts2, and the processing time Td2 with respect to the generation period Tn.

<Embodiment>
Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Configuration of radiated emission measuring device>
First, the configuration of a radiated emission measuring device 1 according to the embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating an example of the configuration of the radiated emission measuring device 1 according to the embodiment.

  The radiated emission measuring device 1 includes a control device 10, an antenna elevating mechanism 21, a rotating mechanism 22, an antenna 30, and a measuring device 40. Note that the antenna elevating mechanism 21 and the rotating mechanism 22 are examples of a moving device.

  The radiated emission measuring device 1 is arranged, for example, inside an anechoic chamber. The anechoic chamber is a dark room having a metal floor surface and a wall surface to which a radio wave absorber is attached. The metal floor is a ground plane.

  The radiated emission measuring device 1 measures the radiated emission from the radiation source 50 in accordance with, for example, EMC (ElectroMagnetic Compatibility) standard, Syspl (CISPR) 16-2-3 standard, or the like. The radiation source 50 is an electronic device such as a computer and a mobile phone terminal. Note that the radiation source 50 may be another device that emits a radiated interference wave or another device that emits a radiated interference wave.

  More specifically, the radiated emission measuring device 1 emits radiated interference from the radiation source 50 while rotating the radiation source 50 by the rotation mechanism 22 in accordance with standards such as the EMC standard and the Sysple 16-2-3 standard. Perform wave measurements. Here, the radiated emission measuring device 1 changes the relative position between the antenna 30 and the radiation source 50 by the antenna elevating mechanism 21 and the rotating mechanism 22. Hereinafter, for convenience of description, changing the relative position between the antenna 30 and the radiation source 50 by the antenna elevating mechanism 21 and the rotating mechanism 22 will be described simply as moving the antenna 30.

  The antenna elevating mechanism 21 supports the antenna 30. The antenna elevating mechanism 21 is attached to the antenna mast M shown in FIG. The antenna mast M is a column that is arranged in a direction perpendicular to a surface on which the antenna mast M is installed. The surface on which the antenna mast M is installed is, for example, the floor of the above-described anechoic chamber. The surface on which the antenna mast M is installed may be another surface such as a wall surface of an anechoic chamber.

  The antenna lifting / lowering mechanism 21 raises / lowers (moves) the antenna 30 along the antenna mast M based on the control performed by the control device 10. That is, the antenna 30 moves up and down in a direction perpendicular to the floor of the anechoic chamber by driving the antenna elevating mechanism 21. Hereinafter, a case where the floor surface is a plane will be described as an example. Hereinafter, as an example, a case will be described in which the direction perpendicular to the floor coincides with the direction of gravity and the direction opposite to gravity. In the following, for convenience of description, the direction of gravity will be referred to as downward or downward, and the direction opposite to gravity will be referred to as upward or upward. Note that another positional relationship may be used as the positional relationship between the surface on which the antenna mast M is installed and the elevation direction of the antenna 30.

  The rotation mechanism 22 rotates an object disposed on the rotation mechanism 22 based on control performed by the control device 10. The rotation mechanism 22 is, for example, a rotary table. In the present embodiment, the table B shown in FIG. Then, on the table B, a radiation source 50 to be measured by the measuring device 40 is arranged. Note that the radiation source 50 may be configured to be disposed on the rotation mechanism 22 without passing through the table B.

  The rotation mechanism 22 rotates the table B and the radiation source 50 around a rotation axis AX along a direction (vertical direction) orthogonal to the floor of the anechoic chamber based on the control performed by the control device 10. The rotation mechanism 22 is preferably arranged such that the rotation axis AX and the antenna mast M are parallel (or substantially parallel). Hereinafter, as an example, a case will be described in which the rotation mechanism 22 is arranged so that the rotation axis AX and the antenna mast M are parallel (or substantially parallel).

  The measuring device 40 measures an electromagnetic wave (for example, the above-mentioned radiated interference wave) received by the antenna 30. More specifically, measuring instrument 40 measures the frequency spectrum of the electric field strength of the electromagnetic wave received by antenna 30. Thereby, measuring device 40 measures the electric field intensity distribution formed on the surface surrounding radiation source 50. The measuring device 40 outputs the measured frequency spectrum to the control device 10. More specifically, based on the control performed by control device 10, measuring device 40 performs sampling time set by control device 10 at each of a plurality of measurement points set on the surface surrounding radiation source 50. Only measure the frequency spectrum. For example, the measuring device 40 is a spectrum analyzer of a superheterodyne system. Hereinafter, for convenience of explanation, each of the plurality of measurement points set on the surface surrounding the radiation source 50 will be simply referred to as a measurement point.

  For example, as shown in FIGS. 2 to 4, the measuring device 40 sweeps (changes) the measurable frequency at a predetermined resolution bandwidth 300 at each sampling time calculated by the control device 10, and Measure the spectrum. FIG. 2 is a diagram illustrating an example of the resolution bandwidth 300 of the measuring device 40 at a certain time T1. FIG. 3 is a diagram illustrating an example of the resolution bandwidth 300 of the measuring device 40 at a time T2 after the time T1. FIG. 4 is a diagram illustrating an example of the resolution bandwidth 300 of the measuring device 40 at a time T3 after the time T2. In this case, the sampling time is a time obtained by dividing the sweep time by the number of sweep points.

  The measuring device 40 is not limited to a superheterodyne type spectrum analyzer, and may be, for example, an FFT type spectrum analyzer. In this case, the sampling time is the sampling time of the time waveform.

  The control device 10 controls the entire radiated emission measuring device 1. Here, a functional configuration of the control device 10 will be described with reference to FIG. FIG. 5 is a diagram illustrating an example of a functional configuration of the control device 10 included in the radiated emission measuring device 1.

  The control device 10 includes a main control unit 100, an input unit 110, an output unit 120, a communication unit 130, and a storage unit 140. These functional units provided in the control device 10 are communicably connected to each other via a bus.

  The input unit 110 is, for example, an input device such as a keyboard, a mouse, and a touchpad. For example, various information is input to the input unit 110 by an operation received from a user of the radiated emission measuring device 1. For example, various measurement conditions for the measurement of the radiated interference wave radiated from the radiation source 50 are input to the input unit 110. The measurement conditions will be described later.

  The output unit 120 is a display device including, for example, a liquid crystal display panel, an organic EL (ElectroLuminescence) display panel, and the like. The output unit 120 outputs information indicating a measurement result or the like of the radiated interference wave radiated from the radiation source 50. The output unit 120 may be configured to be connected to, for example, a collection device that collects various types of information via a network, and to output information indicating the measurement result and the like to the collection device.

  The communication unit 130 includes, for example, a digital input / output port such as a USB, an Ethernet (registered trademark) port, and the like. Here, the control device 10 communicates with each of the antenna elevating mechanism 21, the rotating mechanism 22, and the measuring device 40 via the communication unit 130.

  The main control unit 100 controls the entire control device 10. The main control unit 100 includes a drive control unit 101, an electric field strength analysis unit 102, and an arithmetic processing unit 103. These functional units included in the main control unit 100 are configured such that a processor such as a CPU (Central Processing Unit) executes various instructions (for example, a program, each command included in the program, and the like) stored in the storage unit 140. It is realized by doing. Part or all of the functional units are realized by hardware such as a large scale integration (LSI), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), and a graphics processing unit (GPU). And a configuration realized by cooperation of software and hardware.

  The drive control unit 101 drives at least one of the antenna elevating mechanism 21 and the rotating mechanism 22 to move the antenna 30. More specifically, the drive control unit 101 controls the rotation mechanism 22 based on the calculation result by the calculation processing unit 103, and rotates the rotation mechanism 22. Further, the drive control unit 101 controls the antenna rotation mechanism 23 to move the antenna 30 up or down.

  The drive control unit 101 is configured to be provided in a drive control device that is communicably connected to each of the control device 10, the antenna elevating mechanism 21, and the rotation mechanism 22 instead of the configuration provided in the control device 10. Is also good. In this case, the radiated emission measuring device 1 further includes the drive control device.

  The electric field strength analysis unit 102 analyzes the electric field strength of the radiated disturbance wave radiated from the radiation source 50 based on the frequency spectrum acquired from the measuring device 40. For example, the electric field intensity analysis unit 102 generates an electric field intensity distribution of the radiated disturbance based on the acquired frequency spectrum. The electric field intensity analysis unit 102 applies a median filter to the generated electric field intensity distribution, and removes at least a part of spike noise included in the electric field intensity distribution before applying the median filter. The spike noise will be described later. The electric field intensity analysis unit 102 detects the maximum electric field intensity position based on the electric field intensity distribution after applying the median filter. Here, the maximum electric field intensity position is a position on the surface surrounding the radiation source 50 where the electric field intensity becomes maximum.

  Arithmetic processing unit 103 receives, via input unit 110, a first allowable value for the first probability. Here, the first probability is a probability that after applying a median filter to the electric field intensity distribution generated by the electric field intensity analyzing unit 102, spike noise remains in the electric field intensity distribution. The first allowable value is the maximum value among the values allowed as the value of the first probability when the detection accuracy desired by the user matches the detection accuracy of the maximum electric field strength position.

  The arithmetic processing unit 103 calculates the sampling time Ts based on the received first allowable value. The sampling time Ts is a time for causing the measuring device 40 to measure the radiated disturbance at each of the plurality of measurement points.

  More specifically, the sampling time Ts is a time during which the measuring device 40 measures the radiated disturbance while the tip of the antenna 30 moves from the first measurement point to the second measurement point. That is, the sampling time Ts is a time equal to or shorter than the time during which the tip of the antenna 30 moves from the first measurement point to the second measurement point. Here, the first measurement point is a measurement point from which the measurement device 40 measures the radiated emission, among the plurality of measurement points. The second measurement point is a measurement point at which the tip of the antenna 30 matches immediately after the tip of the antenna 30 matches the first measurement point. For example, when the drive control unit 101 moves the antenna 30 so that the tip of the antenna 30 matches the measurement point T11, the measurement point T12, and the measurement point T13 in the order of the measurement point T11, the measurement point T12, and the measurement point T13, The measurement point T11 is the first first measurement point, and the measurement point T12 is the first second measurement point. In this case, the arithmetic processing unit 103 causes the measuring device 40 to start measuring the radiated interference wave until the sampling time Ts elapses after the tip of the antenna 30 matches the measurement point T11. The arithmetic processing unit 103 causes the measuring device 40 to terminate the measurement of the radiated emission after the sampling time Ts has elapsed since the tip of the antenna 30 coincided with the measurement point T11. In addition, the arithmetic processing unit 103 acquires the frequency spectrum of the radiated disturbance measured by the measuring device 40 from the measuring device 40 until the tip of the antenna 30 coincides with the measurement point T12. In this embodiment, the frequency spectrum acquired from the measuring device 40 at this time is referred to as a frequency spectrum measured at the measurement point T11. When the tip of the antenna 30 coincides with the measurement point T12, the measurement point T12 becomes the second first measurement point, and the measurement point T13 becomes the second second measurement point. The arithmetic processing unit 103 causes the measuring instrument 40 to measure the radiated emission at each of the plurality of measurement points while repeating the exchange of the first measurement point and the exchange of the second measurement point.

  The sampling time Ts calculated by the arithmetic processing unit 103 is a time determined according to the first allowable value. In other words, the sampling time Ts calculated by the arithmetic processing unit 103 is a time suitable for the detection accuracy desired by the user among the detection accuracy of the maximum electric field intensity position. A method of calculating the sampling time by the arithmetic processing unit 103 will be described later.

  The arithmetic processing unit 103 calculates the moving speed of the antenna 30 that receives the radiated disturbance based on the calculated sampling time Ts. The moving speed is a rotation speed (angular speed) at which the rotation mechanism 22 rotates the radiation source 50. The moving speed is an example of a calculation result by the calculation processing unit 103 described above.

  The storage unit 140 is a storage device. The storage unit 140 may be any device as long as it can store information. For example, the storage unit 140 is a hard disk device, an optical disk device, or the like. Further, the storage unit 140 records information on a computer-readable recording medium 141 in response to a request from the main control unit 100. The storage unit 140 reads information from the recording medium 141 in response to a request from the main control unit 100.

  The recording medium 141 is, for example, a hard disk, an optical disk, or the like. The recording medium 141 may be a recording medium on which various programs executed by the main control unit 100 are recorded.

<Multiple measurement points set on the surface surrounding the radiation source>
Hereinafter, a plurality of measurement points set on the surface surrounding the radiation source 50 will be described. FIG. 6 is a diagram illustrating a plurality of measurement points set on a surface surrounding the radiation source 50. In the embodiment, the surface surrounding the radiation source 50 is, as shown in FIG. 6, a circumferential surface of a cylindrical region having a predetermined radius r around the rotation axis AX of the rotation mechanism 22.

  As shown in FIG. 6, on the surface surrounding the radiation source 50, a plurality of measurement points are set at equal intervals along the vertical and circumferential directions on the surface. Each of the plurality of black circles shown in FIG. 6 is an example of such a plurality of measurement points. The measurement point MP shown in FIG. 6 is one of such a plurality of measurement points. In addition, some or all of the plurality of measurement points set on the surface surrounding the radiation source 50 are set so as to be arranged in a different arrangement from the equal intervals, instead of being configured to be arranged in an equal interval. A configuration may be used, or a configuration set so as to be arranged irregularly may be used.

  The plurality of measurement points as shown in FIG. 6 may be stored in the control device 10 as virtual points located on a plane surrounding the radiation source 50, and the measurement points among the positions on the plane may be measured. The configuration may be such that the control device 10 stores the position where the tip of the antenna 30 is located at the timing when the device 40 starts measuring the radiated disturbance.

  Here, the antenna 30 is supported by the antenna lifting / lowering mechanism 21 such that its tip is located at a position separated from the rotation axis AX of the rotation mechanism 22 by a predetermined radius r. In this case, the tip of the antenna 30 is located on a surface surrounding the radiation source 50. Thereby, the control device 10 can control at least one of the antenna elevating mechanism 21 and the rotating mechanism 22 and move the tip of the antenna 30 so as to coincide with each of the plurality of measurement points in a predetermined order.

<Process in which radiated emission measuring equipment detects maximum electric field strength position>
Hereinafter, a process in which the radiated emission measuring device 1 detects the maximum electric field intensity position will be described with reference to FIG. FIG. 7 is a diagram illustrating an example of a flow of a process in which the radiated emission measuring device 1 detects a maximum electric field intensity position. Hereinafter, as an example, a case will be described in which the height of the tip of antenna 30 matches the lower limit of the measurement height range at the timing before the processing of step S110 is performed. The measurement height range is a range in which the tip of the antenna 30 moves vertically.

  The drive control unit 101 receives the above-described measurement conditions via the input unit 110 (Step S110). The measurement conditions include at least the above-described first allowable value and the generation period Tn of the radiated interference wave. In the following, as an example, in addition to the first allowable value and the generation period Tn of the radiated emission, the measurement condition includes a frequency band for measuring the radiated emission, a measurement height range, and a plurality of values set within the measurement height range. The following describes a case where the measurement point interval, the measurement angle range, the interval between a plurality of measurement points set within the measurement angle range, the detection method, and the RBW (Resolution Band Width) are included. Here, the measurement angle range is a range of a rotation angle in which the rotation mechanism 22 can rotate the radiation source 50. Further, the generation period Tn of the radiated emission is the maximum period assumed by the user as the generation period of the radiated emission to be measured by the radiated emission measurement device 1.

  Next, the arithmetic processing unit 103 calculates a sampling time Ts suitable for the detection accuracy desired by the user among the detection accuracy of the maximum electric field intensity position based on the measurement conditions received by the drive control unit 101 in step S110. (Step S120). More specifically, in step S120, the arithmetic processing unit 103 calculates the sampling time Ts based on the first allowable value included in the measurement condition.

  Here, a method in which the arithmetic processing unit 103 calculates the sampling time Ts in step S120 will be described.

  If the capture rate of the radiated disturbance is less than 100%, the electric field intensity distribution includes a point at which the level of the electric field intensity becomes nonlinearly low (falls). The aforementioned spike noise refers to such a point. Therefore, in the following, this point will be described as spike noise. Here, that the level of the electric field strength decreases nonlinearly means that the rate of change of the level of the electric field strength is equal to or higher than a predetermined threshold. Since the definition of the spike noise is publicly known, further detailed description is omitted.

  FIG. 8 is a diagram illustrating an example of the electric field intensity distribution when the capture rate of the radiated disturbance is less than 100%. The horizontal axis of the graph shown in FIG. 8 indicates a circumferential position on the surface among the positions surrounding the radiation source 50. The position is represented by an azimuth angle from the rotation axis AX toward the position where the tip of the antenna 30 was located among the positions on the surface surrounding the radiation source 50. The vertical axis of the graph indicates the position in the height direction (that is, the vertical direction) among the positions on the surface surrounding the radiation source 50. The position is represented by the height at which the tip of the antenna 30 was located. Each grid point of the graph indicates a plurality of measurement points set on the surface. Further, rectangular points included in the graph indicate spike noise. As shown in FIG. 8, the spike noise is included in the electric field intensity distribution when the capture rate of the radiated interference is less than 100%.

  As a method for removing spike noise, a method using a median filter is known in the field of image processing. The median filter applied to a certain image P (not shown) has a value (for example, a first point value) to which the median filter is applied among a plurality of points (for example, points represented by pixels) included in the image P. A value of the first point (eg, the brightness value of the second point) and a value of a second point (one or more points correspond to the second point) adjacent to the first point among the plurality of points. This is a filter that calculates the median value of the first point and replaces the calculated median value with the value of the first point.

  FIG. 9 is a diagram illustrating each of the nine points included in the image P before the median filter is applied. In the example illustrated in FIG. 9, the nine points include one spike noise. FIG. 10 is a diagram illustrating an example of a result obtained by applying the median filter to the spike noise illustrated in FIG. The horizontal axis of the graph shown in FIGS. 9 and 10 indicates a position on the image P. The vertical axis of the graph indicates a value of a point on the image P (for example, a lightness value). A point P1 illustrated in FIG. 9 illustrates an example of a spike noise included in the image P. Point P4 shown in FIG. 10 shows an example of the result after applying the median filter to point P1 shown in FIG. Each of the points P2 and P3 shown in FIGS. 9 and 10 indicates a point around the point P1.

  As shown in FIGS. 9 and 10, when the median filter is applied to the point P1 shown in FIG. 9, the value of the point P1 is shown in FIG. 9 like the value of the point P4 shown in FIG. Is replaced by the median of the three points P1, P2 and P3. The median filter performs such replacement of the value of the point P1 with the median value for all the points included in the image P. Since the median filter is a known filter, further detailed description is omitted.

  Regarding the points included in the image P after applying the median filter, the value of the first point described above may be replaced with the same value as the value of the second point adjacent to the first point. Therefore, when the median filter is applied to the electric field intensity distribution instead of the image P, the electric field intensity distribution after applying the median filter may be a non-smooth distribution in which the level of the electric field intensity changes non-linearly. However, when the electric field intensity distribution is measured with sufficient resolution (for example, when the interval between the measurement points is set to about half a wavelength of the radiated interference wave), the electric field intensity distribution after applying the median filter further applies the smoothing filter. By doing so, a smooth distribution is obtained in which the level of the electric field intensity changes linearly. As described above, the electric field intensity distribution obtained as a smooth distribution by applying the median filter and the smoothing filter is substantially the same as the electric field intensity distribution obtained when the capture ratio of the radiated interference is 100%. Therefore, the radiated emission measuring apparatus 1 applies both the median filter and the smoothing filter to the electric field intensity distribution obtained when the capture rate of the radiated emission is less than 100%, thereby obtaining the radiated emission. An electric field intensity distribution substantially similar to the case where the wave capture rate approaches 100% can be generated.

  On the other hand, the occurrence of spike noise in the electric field intensity distribution is caused by the trapping rate of the radiated interference wave being less than 100%. More specifically, the generation of the spike noise is caused by the fact that the long-period noise whose generation cycle is longer than the sampling time set in the radiated emission measuring device 1 is not measured by the radiated emission measurement device 1. I have. This means that the probability that spike noise occurs in the electric field intensity distribution can be approximated by the probability that the long-period noise is not measured by the radiated emission measuring device 1. Therefore, in the following, the probability that spike noise will occur in the electric field strength distribution will be approximated by the probability that long-period noise will not be measured by the radiated emission measuring device 1. Here, when the probability that the long-period noise is not measured by the radiated emission measuring device 1 is indicated by X, and the total number of measurement points is indicated by Nm, N spike noises are generated in the electric field intensity distribution obtained by the measurement. The probability (ie, the probability that the long-period noise is not measured by the radiated emission measuring device 1) is expressed by the following equation (1) using a binomial distribution. Note that the probability X is an example of a second probability.

  When a one-dimensional median filter is applied to the electric field intensity distribution, each of the three points of the points included in the electric field intensity distribution, that is, a point to which the median filter is applied and two points adjacent to the point It is necessary to calculate the median of the levels. Therefore, if the plurality of spike noises included in the electric field intensity distribution are not adjacent to each other, the plurality of spike noises are removed from the electric field intensity distribution by the median filter. Here, the probability that N spike noises generated in the electric field intensity distribution are adjacent can be expressed by the following equation (2) by the permutation using Nm and N described above.

  The product of the above equations (1) and (2) is as shown in the following equation (3), where N spike noises are generated in the electric field intensity distribution and N spike noises are generated in the electric field intensity distribution. Represents the probability that the spike noises are adjacent to each other.

  Here, when spike noises generated in the electric field intensity distribution are adjacent to each other, even if a median filter is applied to the electric field intensity distribution, it is not possible to remove all spike noises from the electric field intensity distribution. From this, the above equation (3) represents the probability that N spike noises occur in the electric field intensity distribution and that the spike noise remains in the electric field intensity distribution after applying the median filter.

  Therefore, the probability P (X) that any one of 1 to Ns spike noises occur in the electric field intensity distribution and that the spike noise remains in the electric field intensity distribution after applying the median filter is as follows. Equation (4). Note that the probability P (X) is an example of the above-described first probability.

  Here, the probability X that long-period noise is not measured by the radiated emission measuring device 1 is calculated by the following equation (5) using the total number Nm of measurement points and the number Ns of spike noises generated in the electric field intensity distribution. Can be expressed as follows.

  When the probability P (X) is determined to be a certain value, the number Ns of spike noises generated in the electric field intensity distribution is calculated by numerical calculation based on the above equations (4) and (5). Then, the probability X is calculated based on the calculated number Ns and Expression (5). This means that, in this case, the probability X is uniquely determined by the above equations (4) and (5). The method of performing the numerical calculation may be various optimization methods, a Monte Carlo simulation, or another numerical calculation method.

  Here, the above-described first allowable value can be substituted for the probability P (X). When the first allowable value is substituted for the probability P (X), the probability X determined by the above equations (4) and (5) can be interpreted as the second allowable value. The second allowable value is the maximum value of the values allowed as the probability X when the detection accuracy desired by the user and the detection accuracy of the maximum electric field strength position match. In other words, the second allowable value is a probability that the long-period noise does not need to be measured by the radiated emission measuring device 1 in this case. That is, when the first allowable value desired by the user is given as the probability P (X), the probability X is calculated as the second allowable value by using the above equations (4) and (5). Note that an expression obtained by combining the above expressions (4) and (5) is an example of a first expression that associates the first probability with the second probability.

  On the other hand, the probability X can be expressed by the following equation (6) using the sampling time Ts and the above-described generation period Tn of the radiated interference wave.

  Here, the maximum value of the generation period Tn of the radiated disturbance to be measured is determined by the movement time Tm of the antenna 30 moving between the measurement points because the radiated disturbance is measured every time the antenna 30 moves between the measurement points. is there. That is, the movement time Tm is determined by the generation cycle Tn received by the control device 10 as a measurement condition. The moving time Tm is determined based on the sampling time Ts and various processes (for example, a process for generating a frequency spectrum, a process for generating a frequency spectrum, This is a value that is equal to or more than the sum of the processing time Td and the processing of outputting the spectrum to the control device 10). Note that the minimum value of the moving time Tm is the sampling time Ts when the processing time Td is 0.

  Here, the following equation (7) is an equation obtained by solving the above equation (6) for the sampling time Ts.

  When the probability X is the above-described second allowable value, the sampling time Ts is calculated by using the above equation (7) and the generation period Tn of the radiated disturbance wave included in the measurement condition received by the control device 10 in step S110. Can be calculated based on

  Here, for convenience of description, the sampling time Ts when the median filter is not applied to the electric field intensity distribution is hereinafter referred to as sampling time Ts1, and the sampling time Ts when the median filter is applied to the electric field intensity distribution is referred to as a sampling time. This will be described as Ts2. The sampling time Ts1 is, for example, a time determined by a user's trial and error. The sampling time Ts2 is the sampling time Ts calculated by the arithmetic processing unit 103 in step S120.

  The number of spike noises included in the electric field intensity distribution when the median filter is not applied to the electric field intensity distribution is larger than the number of spike noises included in the electric field intensity distribution when the median filter is applied to the electric field intensity distribution. For this reason, the probability X in this case becomes larger than the second allowable value according to the number of the spike noises in this case. This means that unless the sampling time Ts1 is longer than the sampling time Ts2, the detection accuracy of the maximum electric field intensity position will be worse than the detection accuracy desired by the user.

  Conventionally, even when the median filter is applied to the electric field intensity distribution, there is no method for knowing the sampling time of a suitable length, and therefore, the sampling time Ts1 has to be determined (optimized) by trial and error.

  On the other hand, in the method of calculating the sampling time Ts2 in step S120, the sampling time Ts2 is calculated by the user giving the first allowable value. For this reason, the radiated emission measuring device 1 can calculate the optimized sampling time Ts2 without performing a trial and error.

  According to the method as described above, in step S120, the arithmetic processing unit 103 calculates the first allowable value included in the measurement condition received by the drive control unit 101 in step S110, the above equation (4), and the above equation (4). 5), the probability X when the probability P (X) is the first allowable value is calculated as the second allowable value. Then, the arithmetic processing unit 103 calculates the probability X based on the calculated second allowable value, the above equation (7), and the generation cycle Tn included in the measurement condition received by the drive control unit 101 in step S110. The sampling time Ts in the case of the second allowable value is calculated as the sampling time Ts2.

  In the radiated emission measuring device 1, since the sampling time Ts2 can be shorter than the sampling time Ts1, the data amount measured by the measuring device 40 is reduced. As a result, the processing time Td of the measuring device 40 when the measuring device 40 performs measurement by the sampling time Ts1 can also be shortened.

  Here, for convenience of explanation, the processing time Td of the measuring device 40 when the measuring device 40 performs measurement using the sampling time Ts1 will be referred to as the processing time Td1. In the following, for convenience of description, the processing time Td of the measuring device 40 when the measuring device 40 performs measurement using the sampling time Ts2 will be referred to as the processing time Td2. In the following, for convenience of description, the moving time Tm obtained by adding Ts1 and Td1 will be referred to as the moving time Tm1. In the following, for convenience of description, the moving time Tm obtained by adding Ts2 and Td2 will be referred to as the moving time Tm2.

  FIG. 11 is a diagram illustrating the relative lengths of the moving time Tm1, the sampling time Ts1, and the processing time Td1 with respect to the generation cycle Tn of the radiated disturbance. FIG. 12 is a diagram illustrating the relative lengths of the movement time Tm2, the sampling time Ts2, and the processing time Td2 with respect to the generation cycle Tn.

  As shown in FIGS. 11 and 12, the radiated emission measuring device 1 can reduce the total measurement time of the radiated emission by using the sampling time Ts2 calculated by the arithmetic processing unit 103 in step S120. . Here, the total measurement time of the radiated emission is the total measurement time of the radiated emission measurement device 1 measuring the radiated emission. In addition, as shown in FIGS. 11 and 12, when the relationship between the sampling time Ts2 and the processing time Td2 is known in advance, the user can calculate the optimal movement time Tm2 of the antenna 30.

  After the processing of step S120 is performed, the arithmetic processing unit 103 calculates the moving speed of the antenna 30 described above (step S130). For example, the arithmetic processing unit 103 calculates the moving speed of the antenna 30 based on the measurement conditions received by the drive control unit 101 in step S110 and the sampling time Ts2 calculated in step S120. Here, in step S130, the arithmetic processing unit 103 calculates the movement time Tm2 of the antenna 30 based on the sampling time Ts2 and the processing time Td2. The arithmetic processing unit 103 calculates the moving speed of the antenna 30 by dividing the interval between a plurality of measurement points included in the measurement condition by the calculated moving time Tm2. The interval between the plurality of measurement points is an interval between the plurality of measurement points set within the measurement angle range.

  Next, the electric field strength analyzer 102 sets the detection method and the RBW included in the measurement conditions received in step S110 in the measuring device 40, and sets the sampling time Ts2 calculated in step S120 in the measuring device 40 ( Step S140).

  Next, the drive control unit 101 controls the rotation mechanism 22 based on the measurement conditions received in step S110, and rotates the rotation mechanism 22 until the rotation angle of the rotation mechanism 22 matches the start angle (step S150). Here, the rotation angle of the rotation mechanism 22 refers to an angle at which the radiation source 50 is rotated from a reference position by the rotation mechanism 22. The start angle is a lower limit value in the measurement angle range. Note that the measurement angle range is included in the measurement conditions received by the drive control unit 101 in step S110, as described above.

  Next, the electric field strength analysis unit 102 causes the measuring device 40 to start measuring the radiated interference wave and starts acquiring the frequency spectrum from the measuring device 40 (step S160). Here, the electric field strength analysis unit 102 compares the frequency spectrum acquired from the measuring device 40 with the current height of the antenna 30 and the rotation angle of the rotation mechanism 22 at the timing when the rotation mechanism 22 started to rotate immediately before. The information is stored in the storage unit 140 in association with each other. That is, the electric field strength analysis unit 102 stores the frequency spectrum in the storage unit 140 in association with the information indicating the measurement point at which the tip of the antenna 30 coincides immediately before.

  Next, the drive control unit 101 starts the rotation of the rotation mechanism 22 (Step S170). At this time, the drive control unit 101 matches the rotation speed of the rotation mechanism 22 with the movement speed of the antenna 30 calculated in step S130. Here, starting the rotation of the rotation mechanism 22 means starting the rotation of the radiation source 50 by the rotation mechanism 22. The rotation speed of the rotation mechanism 22 means the rotation speed of the radiation source 50 rotated by the rotation mechanism 22.

  Next, the electric field intensity analysis unit 102 waits until the sampling time Ts2 calculated in step S120 elapses from the timing immediately before the acquisition of the frequency spectrum from the measurement device 40, which started the acquisition (step S120). Step S180).

  When it is determined that the sampling time Ts2 has elapsed (step S180-YES), the electric field intensity analyzer 102 causes the measuring device 40 to end the measurement of the radiated disturbance and ends the acquisition of the frequency spectrum from the measuring device 40. (Step S190).

  Next, the drive control unit 101 determines whether or not the rotation angle of the rotation mechanism 22 matches the upper limit in the measurement angle range described above (step S200).

  When determining that the rotation angle of the rotation mechanism 22 does not match the upper limit value in the measurement angle range (step S200-NO), the drive control unit 101 waits until the tip of the antenna 30 matches the measurement point (step S200-NO). Step S210). The method of determining whether or not the tip of the antenna 30 matches the measurement point in step S210 may be any method, and a detailed description thereof will be omitted.

  When the drive control unit 101 determines that the tip of the antenna 30 coincides with the measurement point (step S210-YES), the electric field intensity analysis unit 102 causes the measurement device 40 to start measuring the radiated interference wave, and The acquisition of the frequency spectrum from is started (step S220). Here, the electric field strength analysis unit 102 compares the frequency spectrum acquired from the measuring device 40 with the current height of the antenna 30 and the rotation angle of the rotation mechanism 22 at the timing when the rotation mechanism 22 started to rotate immediately before. The information is stored in the storage unit 140 in association with each other. That is, the electric field strength analysis unit 102 stores the frequency spectrum in the storage unit 140 in association with the information indicating the measurement point at which the tip of the antenna 30 coincides immediately before. Then, the electric field strength analyzer 102 transitions to step S180, and the sampling time Ts2 calculated in step S120 has elapsed since the timing immediately before the acquisition of the frequency spectrum from the measuring instrument 40 was started. Wait again until you do.

  On the other hand, when determining that the rotation angle of the rotation mechanism 22 matches the upper limit value in the measurement angle range (step S200-YES), the drive control unit 101 determines that the current height of the tip of the antenna 30 is equal to the above-described measurement value. It is determined whether or not the value matches the upper limit of the high range (step S230).

  When the drive control unit 101 determines that the current height of the tip of the antenna 30 does not match the upper limit value of the measured height range (step S230-NO), the drive control unit 101 controls the antenna elevating mechanism 21 to The height of the tip is raised by an interval between a plurality of measurement points set within the measurement height range (step S240). Note that the measurement height range is included in the measurement conditions received in step S110. Then, after the process of step S240 is performed, the drive control unit 101 transitions to step S150, and rotates the rotation mechanism 22 again until the rotation angle of the rotation mechanism 22 matches the start angle.

  On the other hand, when the drive control unit 101 determines that the height of the tip of the antenna 30 matches the upper limit value of the measurement height range (step S230-YES), the electric field strength analysis unit 102 (That is, all frequency spectra stored in the storage unit 140), an electric field intensity distribution formed on the surface surrounding the radiation source 50 is generated (step S250). The method for generating the electric field intensity distribution in step S250 may be a known method or a method to be developed.

  Next, the electric field intensity analysis unit 102 applies a median filter to the electric field intensity distribution generated in step S250. Then, the electric field intensity analysis unit 102 applies the above-described smoothing filter to the electric field intensity distribution after applying the median filter (step S260). Thereby, the electric field intensity analysis unit 102 can remove at least a part of the spike noise included in the electric field intensity distribution. As a result, the radiated emission measuring device 1 can suppress a decrease in the detection accuracy of the maximum electric field strength position due to the overlook of the long-period noise.

  Next, the electric field intensity analysis unit 102 detects the aforementioned maximum electric field intensity position based on the electric field intensity analysis after applying the smoothing filter in step S260 (step S270), and ends the processing.

<Result of demonstration experiment>
Hereinafter, a verification experiment performed to verify the validity of the calculation of the sampling time Ts2 by the radiated emission measuring device 1 will be described.

  In the demonstration experiment, the horizontal distance between the transmission source and the antenna 30 was set to 3 m, the height of the transmission source was set to 1.5 m, and the maximum height of the radiation source at a distance of 3 m discussed in the international standard CISRP was set to 1.5 m. Analysis was performed by sweeping at a half wavelength from 1 m to 4 m. The analysis method used Fris's formula, and the analysis frequency was 1000 MHz. Furthermore, in the demonstration experiment, spike noise was randomly generated (with uniform distribution) on the electric field intensity distribution, analyzed 2000 times, and the electric field intensity calculated from the position where the maximum electric field intensity was obtained before and after applying the median filter. The deviation was calculated for each analysis.

  In the verification experiment, the above analysis procedure was performed while changing the probability of occurrence of spike noise, and the probability that the calculated deviation was 1 dB or more (hereinafter referred to as evaluation probability) was 99.73% (normal distribution was assumed). In this case, the probability of occurrence of spike noise and the probability of remaining spike noise were calculated.

  As a result of the analysis, in the demonstration experiment, the probability of occurrence of spike noise with an evaluation probability of 99.73% was 30%, and the probability of remaining spike noise was 20%.

  Here, based on the probability that the spike noise remains, a comparison is made between the condition that the evaluation probability before applying the median filter is 99.73% and the condition that the evaluation probability after applying the median filter is 99.73%. Was done.

  As conditions before the application of the median filter, if the conditions that the generation period Tn of the radiated interference wave is 100 ms, the sampling time Ts1 is 80 ms, the processing time Td1 is 0.25 × Ts1, and the moving time Tm is 100 ms are selected, the sampling time Ts1 becomes 70 ms, and the processing time Td1 was 17.5 m. Therefore, in the demonstration experiment, it was found that when the median filter was applied to the electric field intensity distribution, the moving time could be shortened by 12.5 ms and the speed could be increased by 12.5%.

  As described above, by using the radiated emission measuring device 1, the moving time of the antenna 30 can be reduced, and the measurement time of the radiated emission can be reduced.

<Other effects obtained by the radiated emission measuring device>
For example, when using a real-time spectrum analyzer or the like as the measuring device 40 to make the capture rate of the radiated interference wave close to 100%, it is necessary to make the sampling time Ts, the generation period Tn, and the movement time Tm substantially the same. However, depending on the specifications of the measuring instrument 40 and the specifications of the rotating mechanism 22, the setting resolution of the sampling time Ts and the moving time Tm may be insufficient. For example, when it is necessary to set the sampling time at 99.8 ms for a generation cycle of 100 ms, such setting cannot be performed if the setting resolution of the measuring instrument 40 is 1% or less. In this case, by using a method in which the radiated emission measuring device 1 calculates the sampling time, the capture rate of the radiated emission is brought close to 100% even when the setting resolution of the sampling time Ts and the moving time Tm is low. be able to. As a result, the sampling time can be reduced, and depending on the conditions, measurement can be performed even at the set resolution.

  As described above, the radiated emission measuring device (in the example described above, the radiated emission measuring device 1) according to the embodiment uses the radiation source of the radiated emission (the radiation source 50 in the example described above). Applying a median filter to the electric field intensity distribution formed on the surrounding surface, and detecting the maximum electric field intensity position where the electric field intensity becomes maximum on the surface based on the electric field intensity distribution after applying the median filter. A wave measuring apparatus, comprising a control device (in the example described above, the control device 10), wherein the control device has a first probability (in the above description) that a spike noise remains in the electric field intensity distribution after applying the median filter. In the example described, the first allowable value for the probability P (X)) and the generation period of the radiated disturbance (in the example described above, the generation period Tn of the radiated disturbance). And a first equation (in the example described above, equation (4) and equation (5) in which the second probability that the long-period noise is not measured (probability X in the example described above) is associated with the first probability. ) And the received first allowable value, a second probability in the case where the first probability is the first allowable value is calculated as a second allowable value, and a plurality of measurement points set on the surface are calculated. In each case, a sampling time (sampling time Ts in the example described above) for measuring the radiated disturbance is associated with a second probability and the generation cycle (in the example described above, equation (7)). Based on the calculated second allowable value, a sampling time (the sampling time Ts2 in the example described above) when the second probability is the second allowable value is calculated. Thereby, the radiated emission measuring device 1 can suppress an increase in the total measurement time of the radiated emission while suppressing a decrease in the detection accuracy of the maximum electric field intensity position due to a miss of the long-period noise. .

  The radiated emission measuring device uses a configuration in which the control device calculates the moving speed of the antenna (in the example described above, the antenna 30) that receives the radiated emission based on the calculated sampling time. You may.

  In the radiated emission measuring device, the first expression is represented by the above expressions (4) and (5), P (X) represents the first probability, and Ns represents the electric field intensity distribution. A configuration may be used in which the number of spike noises is included, Nm indicates the number of measurement points, and X indicates the second probability.

  In the radiated emission measuring apparatus, the second expression is represented by the above expression (7), Ts represents a sampling time, Tn represents a long-period noise generation period, and X represents a A configuration indicating two probabilities may be used.

  The radiated emission measuring device includes an antenna for receiving the radiated emission, a moving device for moving the antenna relatively to the radiation source (in the example described above, the antenna elevating mechanism 21 and the rotating mechanism 22). The control device controls the moving device based on the calculated sampling time, moves the antenna to each of the plurality of measurement points, measures the radiated disturbance, and measures the radiated disturbance (in the above description). In the example described, an electric field intensity distribution is generated based on the frequency spectrum measured by the measuring device 40), a median filter is applied to the generated electric field intensity distribution, and based on the electric field intensity distribution after applying the median filter. A configuration for detecting the position of the maximum electric field strength may be used.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and may be changed, replaced, deleted, or the like without departing from the gist of the present invention. May be done.

  Further, a program for realizing the function of an arbitrary component in the above-described device (for example, the control device 10) is recorded on a computer-readable recording medium, and the program is read and executed by a computer system. You may do so. Here, the “computer system” includes an OS (Operating System) and hardware such as peripheral devices. The “computer-readable recording medium” refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD (Compact Disk) -ROM, and a storage device such as a hard disk built in a computer system. . Further, the “computer-readable recording medium” refers to a volatile memory (RAM) inside a computer system that is a server or a client when a program is transmitted through a network such as the Internet or a communication line such as a telephone line. And those holding programs for a certain period of time.

Further, the above program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the "transmission medium" for transmitting a program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.
Further, the above program may be a program for realizing a part of the functions described above. Furthermore, the above-mentioned program may be a program that can realize the above-described functions in combination with a program already recorded in the computer system, that is, a so-called difference file (difference program).

REFERENCE SIGNS LIST 1 radiated emission measuring device, 10 control device, 21 antenna elevating mechanism, 22 rotating mechanism, 23 antenna rotating mechanism, 30 antenna, 40 measuring instrument, 50 radiation source, 100 main control unit DESCRIPTION OF SYMBOLS 101 ... drive control part, 102 ... electric field strength analysis part, 103 ... arithmetic processing part, 110 ... input part, 120 ... output part, 130 ... communication part, 140 ... storage part, 141 ... recording medium, 300 ... resolution bandwidth, M: Antenna mast

Claims (5)

Applying a median filter to the electric field intensity distribution formed on the surface surrounding the radiation source of the radiated interference wave, based on the electric field intensity distribution after applying the median filter, the electric field intensity is maximized on the surface A radiated emission measuring device that detects a maximum electric field intensity position,
Equipped with a control device,
The control device includes:
A first allowable value for a first probability that a spike noise remains in the electric field intensity distribution after applying the median filter, and a generation cycle of the radiated interference wave are received,
Based on a first expression that associates a second probability that a long-period noise is not measured with the first probability and the received first allowable value, the second probability in the case where the first probability is the first allowable value 2 Calculate the probability as a second tolerance,
Based on a sampling time for measuring the radiated disturbance at each of a plurality of measurement points set on the surface, a second expression that associates the second probability with the generation cycle, and the calculated second allowable value. Calculating the sampling time when the second probability is the second allowable value;
Radiated emission measuring device. The control device includes:
Based on the calculated sampling time, calculate the moving speed of the antenna that receives the radiated disturbance,
The radiated emission measuring device according to claim 1. The first equation is represented by the following equations (1) and (2),
P (X) indicates the first probability,
Ns indicates the number of the spike noises included in the electric field intensity distribution,
Nm indicates the number of the measurement points,
X represents the second probability,
The radiated emission measuring device according to claim 1. The second equation is represented by the following equation (3):
Ts indicates the sampling time,
Tn indicates a generation cycle of the long-period noise,
X represents the second probability,
The radiated emission measuring device according to any one of claims 1 to 3. An antenna for receiving the radiated disturbance;
A moving device for moving the antenna relative to the radiation source;
With
The control device includes:
Controlling the moving device based on the calculated sampling time, measuring the radiated disturbance by moving the antenna to each of the plurality of measurement points,
Based on the result of measuring the radiated disturbance, generate the electric field strength distribution,
Applying the median filter to the generated electric field intensity distribution,
Based on the electric field intensity distribution after applying the median filter, the maximum electric field intensity position is detected,
The radiated emission measuring device according to any one of claims 1 to 4.