Radiated electromagnetic noise estimation apparatus and radiated electromagnetic noise estimation method

Abstract

A radiated electromagnetic noise estimation apparatus (3) has a configuration comprising: a first data acquisition unit (11) that, when a reference device is installed at a position separated from a first measurement device (1) by a first distance, acquires first data, which is data obtained by measuring radiated electromagnetic noise of the reference device using the first measurement device (1); and a second data acquisition unit (12) that, when the reference device is installed at a position separated from a second measurement device (2) by a second distance shorter than the first distance, acquires second data, which is data obtained by measuring radiated electromagnetic noise of the reference device using the second measurement device (2). The radiated electromagnetic noise estimation apparatus (3) further comprises: a third data acquisition unit (13) that, when an evaluated device, which is a device being evaluated, is installed at a position separated from the second measurement device (2) by the second distance, acquires third data, which is data obtained by measuring radiated electromagnetic noise of the evaluated device using the second measurement device (2); and a noise estimation unit (14) that, from the first data, the second data, and the third data, estimates radiated electromagnetic noise of the evaluated device when the evaluated device is installed at a position separated from the first measurement device (1) by the first distance.

Description

Radiation electromagnetic noise estimation device and radiation electromagnetic noise estimation method

[0001] The present disclosure relates to a radiated electromagnetic noise estimation device and a radiated electromagnetic noise estimation method.

[0002] There is a radiated electromagnetic noise estimation device that estimates the radiated electromagnetic noise of a device to be evaluated. For example, Patent Document 1 discloses an example of such a radiated electromagnetic noise estimation device. The device acquires the radiated electromagnetic noise of the device to be evaluated from a simplified measurement site having simpler equipment than a standard measurement site whose design standards for measuring radiated electromagnetic noise meet the international standard (CISPR22), and corrects the radiated electromagnetic noise using the radiated electromagnetic noise acquired from the standard measurement site. Note that CISPR22 was abolished in March 2017 and integrated into CISPR33.

[0003] Japanese Patent Application Laid-Open No. 2002-14126

[0004] In order to measure radiated electromagnetic noise, the device disclosed in Patent Document 1 requires the existence of a simplified measurement site with equipment that meets roughly the same design standards as the equipment at the standard measurement site, even if the equipment is simpler than that at the standard measurement site.The device disclosed in Patent Document 1 has the problem that, unless such a simplified measurement site exists, it cannot estimate the radiated electromagnetic noise of the equipment to be evaluated.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a radiated electromagnetic noise estimation device that can estimate the radiated electromagnetic noise of a device to be evaluated even without a simple measurement site.

[0006] A radiated electromagnetic noise estimation device according to the present disclosure includes a first data acquisition unit that acquires first data, which is data obtained by measuring radiated electromagnetic noise from a reference device using a first measuring device when the reference device is installed at a first distance from the first measuring device, a second data acquisition unit that acquires second data, which is data obtained by measuring radiated electromagnetic noise from the reference device using the second measuring device when the reference device is installed at a second distance that is shorter than the first distance from the second measuring device, a third data acquisition unit that acquires third data, which is data obtained by measuring radiated electromagnetic noise from the evaluation target device using the second measuring device when the evaluation target device is installed at the second distance from the second measuring device, and a noise estimation unit that estimates radiated electromagnetic noise from the evaluation target device when the evaluation target device is installed at the first distance from the first measuring device based on the first data, the second data, and the third data.

[0007] According to the present disclosure, it is possible to estimate the radiated electromagnetic noise of a device to be evaluated even without a simple measurement site.

[0008] 1 is an explanatory diagram showing a reference device Ref installed at a position a first distance away from a first measuring device. FIG. 2 is an explanatory diagram showing a reference device Ref or an evaluation target device EUT installed at a position a second distance away from a second measuring device. FIG. 3 is a configuration diagram showing a radiated electromagnetic noise estimation device 3 according to embodiment 1. FIG. 4 is a hardware configuration diagram showing the hardware of the radiated electromagnetic noise estimation device 3 according to embodiment 1. FIG. 5 is a hardware configuration diagram of a computer when the radiated electromagnetic noise estimation device 3 is realized by software, firmware, or the like. FIG. 6 is a flowchart showing a radiated electromagnetic noise estimation method, which is a processing procedure of the radiated electromagnetic noise estimation device 3. FIG. 7 is an explanatory diagram showing the relationship between the near field strength and frequency of radiated electromagnetic noise. FIG. 8 is an explanatory diagram showing the relationship between the far field strength and frequency of radiated electromagnetic noise. FIG. 9 is a configuration diagram showing a radiated electromagnetic noise estimation device 3 according to embodiment 2. FIG. 10 is a hardware configuration diagram showing the hardware of the radiated electromagnetic noise estimation device 3 according to embodiment 2. FIG. 11 is an explanatory diagram showing a first difference Xf, which is the difference between the peak value Ref_f of the first data and the noise test standard value TH. FIG. 12 is a configuration diagram showing a radiated electromagnetic noise estimation device 3 according to embodiment 3. 1 is a hardware configuration diagram showing the hardware of a radiated electromagnetic noise estimation device 3 according to a third embodiment. FIG. 2 is an explanatory diagram showing the relationship between the near field strength and frequency of radiated electromagnetic noise. FIG. 3 is a configuration diagram showing a radiated electromagnetic noise estimation device 3 according to a fourth embodiment. FIG. 4 is a hardware configuration diagram showing the hardware of a radiated electromagnetic noise estimation device 3 according to the fourth embodiment. FIG. 5 is an explanatory diagram showing a measurement position x0 corresponding to the peak value Ref_n of the second data and a measurement position x3 corresponding to the peak value EUT_n of the third data. FIG. 6 is an explanatory diagram showing the measurement position of radiated electromagnetic noise in the horizontal direction by a second measuring device 2. FIG. 7 is an explanatory diagram showing the relationship between ld / dn and the azimuth angle θ. FIG. 8 is an explanatory diagram showing the measurement position of radiated electromagnetic noise in the vertical direction by a second measuring device 2. FIG. 9 is an explanatory diagram showing the relationship between the positions where a reference device Ref and an evaluation target device EUT are installed and the near measurement element 2a of the second measuring device 2. FIG. 10 is an explanatory diagram showing the relationship between the near measurement distance dn and the measurement ranges hd_h, hd_l of radiated electromagnetic noise in the vertical direction.

[0009] In order to explain the present disclosure in more detail, embodiments of the present disclosure will be described below with reference to the accompanying drawings.

[0010] Embodiment 1. Figure 1 is an explanatory diagram showing a reference device Ref installed at a position separated by a first distance from a first measuring device. Figure 2 is an explanatory diagram showing a reference device Ref or an evaluation target device EUT installed at a position separated by a second distance from a second measuring device. As shown in Figure 1, the reference device Ref is installed on a turntable that can rotate 360 ​​degrees in an anechoic chamber. In Figure 1, only the antenna of the first measuring device 1 is shown as the first measuring device. The far measurement distance d shown in Figure 1 is a first distance, for example, 3 m or 10 m. In the example of Figure 1, the measurement height of the antenna of the first measuring device 1 is 1 to 4 m.

[0011] As shown in FIG. 2 , the reference device Ref or the device under evaluation EUT is placed on a table. In FIG. 2 , only the antenna of the second measuring device 2 is shown as the second measuring device. The proximity measurement distance dn shown in FIG. 2 is the second distance. The second distance is shorter than the first distance. The second distance is, for example, 2 m or less, which fully satisfies the far-field condition at a frequency of 30 MHz. The reference device Ref and the device under evaluation EUT are devices that may emit electromagnetic noise, such as a personal computer, television, microwave oven, or drill. Note that the reference device Ref and the device under evaluation EUT may be devices of the same type, or the reference device Ref may be a product of a certain device before modification, and the device under evaluation EUT may be a product of the device after modification that is expected to emit electromagnetic noise at the same level as the reference device Ref.

[0012] FIG. 3 is a configuration diagram showing a radiated electromagnetic noise estimation apparatus 3 according to embodiment 1. FIG. 4 is a hardware configuration diagram showing hardware of the radiated electromagnetic noise estimation apparatus 3 according to embodiment 1. In FIG. 3, a first measuring device 1 has a far-field measurement antenna 1a and measures the radiated electromagnetic noise of a reference device Ref when the reference device Ref is installed at a position a first distance away from the first measuring device 1. The reference device Ref is, for example, an device whose radiated electromagnetic noise characteristics at the first distance are sufficiently greater than the floor noise during measurement. The floor noise is, for example, environmental noise. The first measuring device 1 outputs first data indicating the measurement results of the radiated electromagnetic noise of the reference device Ref to the radiated electromagnetic noise estimation device 3.

[0013] The second measuring device 2 has a proximity measuring element 2a and measures the radiated electromagnetic noise of the reference device Ref or the radiated electromagnetic noise of the device EUT to be evaluated when either the reference device Ref or the device EUT to be evaluated is installed at a second distance from the second measuring device 2. The second measuring device 2 outputs, to the radiated electromagnetic noise estimation device 3, second data indicating the measurement results of the radiated electromagnetic noise of the reference device Ref and third data indicating the measurement results of the radiated electromagnetic noise of the device EUT to be evaluated.

[0014] The radiated electromagnetic noise estimation device 3 includes a first data acquisition unit 11, a second data acquisition unit 12, a third data acquisition unit 13, and a noise estimation unit 14. The first data acquisition unit 11 is realized, for example, by a first data acquisition circuit 21 shown in FIG. 4. The first data acquisition unit 11 acquires first data, which is data obtained by measuring the radiated electromagnetic noise of the reference device Ref by the first measuring device 1 when the reference device Ref is installed at a position separated by a first distance from the first measuring device 1. The first data acquisition unit 11 outputs the first data to the noise estimation unit 14.

[0015] The second data acquisition unit 12 is realized by, for example, the second data acquisition circuit 22 shown in Fig. 4. The second data acquisition unit 12 acquires second data, which is data obtained by measuring the radiated electromagnetic noise of the reference device Ref by the second measuring device 2 when the reference device Ref is installed at a position separated by a second distance from the second measuring device 2. The second data acquisition unit 12 outputs the second data to the noise estimation unit 14.

[0016] The third data acquisition unit 13 is realized by, for example, the third data acquisition circuit 23 shown in Fig. 4. The third data acquisition unit 13 acquires third data, which is data obtained by measuring radiated electromagnetic noise from the device under evaluation EUT by the second measuring instrument 2 when the device under evaluation EUT is installed at a second distance from the second measuring instrument 2. The third data acquisition unit 13 outputs the third data to the noise estimation unit 14. The measurements of radiated electromagnetic noise relating to the second data and the third data by the second measuring instrument 2 are measurements of the radiated electromagnetic noise at a position where the measurement frequency of the radiated electromagnetic noise satisfies the far-field condition.

[0017] The noise estimation unit 14 is realized by, for example, the noise estimation circuit 24 shown in Fig. 4. The noise estimation unit 14 acquires first data from the first data acquisition unit 11, acquires second data from the second data acquisition unit 12, and acquires third data from the third data acquisition unit 13. From the first data, the second data, and the third data, the noise estimation unit 14 estimates the radiated electromagnetic noise of the evaluation target device EUT when the evaluation target device EUT is installed at a position separated by a first distance from the first measuring instrument 1.

[0018] 3, it is assumed that each of the first data acquisition unit 11, the second data acquisition unit 12, the third data acquisition unit 13, and the noise estimation unit 14, which are components of the radiated electromagnetic noise estimation device 3, is realized by dedicated hardware such as that shown in FIG. 4. That is, it is assumed that the radiated electromagnetic noise estimation device 3 is realized by a first data acquisition circuit 21, a second data acquisition circuit 22, a third data acquisition circuit 23, and a noise estimation circuit 24. Each of the first data acquisition circuit 21, the second data acquisition circuit 22, the third data acquisition circuit 23, and the noise estimation circuit 24 may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof.

[0019] The components of the radiated electromagnetic noise estimation device 3 are not limited to those realized by dedicated hardware, and the radiated electromagnetic noise estimation device 3 may be realized by software, firmware, or a combination of software and firmware. Software or firmware is stored as a program in the memory of a computer. The computer refers to hardware that executes a program, and includes, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, a processor, or a DSP (Digital Signal Processor).

[0020] 5 is a hardware configuration diagram of a computer when the radiated electromagnetic noise estimation device 3 is realized by software, firmware, etc. When the radiated electromagnetic noise estimation device 3 is realized by software, firmware, etc., a program for causing the computer to execute the respective processing procedures of the first data acquisition unit 11, the second data acquisition unit 12, the third data acquisition unit 13, and the noise estimation unit 14 is stored in a memory 31. A processor 32 of the computer then executes the program stored in the memory 31.

[0021] 4 shows an example in which each of the components of the radiated electromagnetic noise estimation device 3 is realized by dedicated hardware, while Fig. 5 shows an example in which the radiated electromagnetic noise estimation device 3 is realized by software, firmware, etc. However, this is merely an example, and some of the components in the radiated electromagnetic noise estimation device 3 may be realized by dedicated hardware, and the remaining components may be realized by software, firmware, etc.

[0022] Next, the operation of the radiated electromagnetic noise estimation device 3 shown in FIG. 3 will be described. FIG. 6 is a flowchart showing a radiated electromagnetic noise estimation method, which is a processing procedure of the radiated electromagnetic noise estimation device 3. First, the reference device Ref is placed on a turntable, as shown in FIG. 1. At this time, the distance between the reference device Ref and the far-field measurement antenna 1a of the first measuring device 1 is a first distance (far-field measurement distance). The first measuring device 1 measures the radiated electromagnetic noise of the reference device Ref when the reference device Ref is placed on the turntable. The first measuring device 1 outputs first data indicating the measurement result of the radiated electromagnetic noise of the reference device Ref to the radiated electromagnetic noise estimation device 3. The first data acquisition unit 11 acquires the first data from the first measuring device 1 (step ST1 in FIG. 6). The first data acquisition unit 11 outputs the first data to the noise estimation unit 14.

[0023] Next, the reference device Ref is placed on a table as shown in FIG. 2. At this time, the distance between the reference device Ref and the proximity measurement element 2a of the second measuring device 2 is a second distance (proximity measurement distance) shorter than the first distance. The second measuring device 2 measures the radiated electromagnetic noise of the reference device Ref when the reference device Ref is placed on the table. The second measuring device 2 outputs second data indicating the measurement results of the radiated electromagnetic noise of the reference device Ref to the radiated electromagnetic noise estimation device 3. The second data acquisition unit 12 acquires the second data from the second measuring device 2 (step ST2 in FIG. 6). The second data acquisition unit 12 outputs the second data to the noise estimation unit 14.

[0024] Next, the evaluation target device EUT is placed on a table as shown in FIG. 2 . At this time, the distance between the evaluation target device EUT and the proximity measurement element 2a of the second measuring device 2 is a second distance (proximity measurement distance). The second measuring device 2 measures the radiated electromagnetic noise of the evaluation target device EUT while the evaluation target device EUT is placed on the table. The second measuring device 2 outputs third data indicating the measurement results of the radiated electromagnetic noise of the evaluation target device EUT to the radiated electromagnetic noise estimation device 3. The third data acquisition unit 13 acquires the third data from the second measuring device 2 (step ST3 in FIG. 6 ). The third data acquisition unit 13 outputs the third data to the noise estimation unit 14.

[0025] 3 acquires the first data, the second data, and the third data in this order. However, the order in which these data are acquired may be any order, such as the second data, the third data, and the first data, or the third data, the first data, and the second data.

[0026] The noise estimation unit 14 acquires first data from the first data acquisition unit 11, acquires second data from the second data acquisition unit 12, and acquires third data from the third data acquisition unit 13. From the first data, second data, and third data, the noise estimation unit 14 estimates the radiated electromagnetic noise of the evaluation target device EUT when the evaluation target device EUT is installed at a position separated by a first distance from the first measuring instrument 1 (step ST4 in FIG. 6 ). The process of estimating radiated electromagnetic noise by the noise estimation unit 14 will be described in detail below.

[0027] First, as shown in FIG. 7, the noise estimation unit 14 identifies a peak value EUT_n of the third data, and calculates a frequency f corresponding to the peak value EUT_n. ＥＵＴ The process of specifying the peak value EUT_n and the frequency f ＥＵＴ Since the calculation processes for (a) and (b) are well-known techniques, detailed description thereof will be omitted. Fig. 7 is an explanatory diagram showing the relationship between the near field strength of radiated electromagnetic noise and frequency. In Fig. 7, the solid line indicates the near field strength of radiated electromagnetic noise as the radiated electromagnetic noise from the device under evaluation EUT when the device under evaluation EUT is installed at a position a second distance away from the second measuring device 2. The dashed line indicates the near field strength of radiated electromagnetic noise as the radiated electromagnetic noise from the reference device Ref when the reference device Ref is installed at a position a second distance away from the second measuring device 2.

[0028] Next, the noise estimation unit 14 calculates the frequency f as the peak value of the second data, as shown in FIG. ＥＵＴ The noise estimation unit 14 calculates the difference Xn between the peak value Ref_n and the peak value EUT_n as shown in the following equation (1): Xn [dB] = Ref_n [dBuV / m] - EUT_n [dBuV / m] (1)

[0029] Next, the noise estimation unit 14 calculates the frequency f as the peak value of the first data, as shown in FIG. ＥＵＴand identifies a peak value Ref_f at the same frequency as the reference device Ref. FIG. 8 is an explanatory diagram showing the relationship between the far field strength of the radiated electromagnetic noise and frequency. In FIG. 8, the dashed line indicates the far field strength of the radiated electromagnetic noise as the radiated electromagnetic noise of the reference device Ref when the reference device Ref is installed at a position a first distance away from the first measuring device 1. The noise estimation unit 14 uses the peak value Ref_f and the difference Xn as shown in the following equation (2) to estimate the radiated electromagnetic noise EUT_f of the device under evaluation EUT when the device under evaluation EUT is installed at a position a first distance away from the first measuring device 1. EUT_f [dBuV / m] = Ref_f [dBuV / m] - Xn [dB] (2) The estimation result of the radiated electromagnetic noise by the noise estimation unit 14 is displayed, for example, on a display device not shown.

[0030] In the first embodiment described above, the radiated electromagnetic noise estimation device 3 is configured to include a first data acquisition unit 11 that acquires first data, which is data obtained by measuring the radiated electromagnetic noise of the reference device by the first measuring device 1 when the reference device is installed at a first distance from the first measuring device 1, and a second data acquisition unit 12 that acquires second data, which is data obtained by measuring the radiated electromagnetic noise of the reference device by the second measuring device 2 when the reference device is installed at a second distance shorter than the first distance from the second measuring device 2. The radiated electromagnetic noise estimation device 3 also includes a third data acquisition unit 13 that acquires third data, which is data obtained by measuring the radiated electromagnetic noise of the evaluation target device by the second measuring device 2 when the evaluation target device is installed at the second distance from the second measuring device 2, and a noise estimation unit 14 that estimates the radiated electromagnetic noise of the evaluation target device when it is installed at the first distance from the first measuring device 1, from the first data, the second data, and the third data. Therefore, the radiated electromagnetic noise estimation device 3 can estimate the radiated electromagnetic noise of the device to be evaluated even without a simple measurement site.

[0031] 3, the noise estimation unit 14 estimates the radiated electromagnetic noise EUT_f of the evaluation target device EUT, assuming that the radiated electromagnetic noise is expressed in terms of electric field strength. However, this is merely an example, and the noise estimation unit 14 may also estimate the radiated electromagnetic noise EUT_f of the evaluation target device EUT, assuming that the radiated electromagnetic noise is expressed in terms of magnetic field strength.

[0032] In the radiated electromagnetic noise estimation device 3 shown in Fig. 3, the first measuring device 1 and the second measuring device 2 each measure the radiated electromagnetic noise of one reference device Ref. However, this is merely an example, and the first measuring device 1 and the second measuring device 2 may each measure the radiated electromagnetic noise of two or more reference devices Ref that have different peak frequencies. In this case, the noise estimation unit 14 selects the radiated electromagnetic noise of the reference device Ref having the frequency f from the two or more reference devices Ref. ＥＵＴ A reference instrument Ref having the same frequency band as the reference instrument Ref is selected, and the frequency f is used as the peak value of the second data for the selected reference instrument Ref. ＥＵＴ Furthermore, the noise estimation unit 14 specifies a peak value Ref_n at the same frequency as the frequency f as the peak value of the first data for the selected reference device Ref. ＥＵＴ The peak value Ref_f at the same frequency as

[0033] In the radiated electromagnetic noise estimation device 3 shown in FIG. 3, the noise estimation unit 14 estimates the frequency f ＥＵＴ The peak value Ref_n at the same frequency as ＥＵＴ However, this is merely an example, and the noise estimation unit 14 may specify a peak value Ref_f at the same frequency as the frequency f as the quasi-peak value of the second data. ＥＵＴ The quasi-peak value Ref_n at the same frequency as ＥＵＴ The quasi-peak value may be, for example, a Quasi Peak (QP) adopted in EMC (Electromagnetic Compatibility) test standards.

[0034] Second Embodiment In a second embodiment, a radiated electromagnetic noise estimation device 3 will be described that includes a necessity determining unit 15 that determines whether or not countermeasures against radiated electromagnetic noise from an equipment under evaluation EUT are necessary.

[0035] Fig. 9 is a configuration diagram showing a radiated electromagnetic noise estimation device 3 according to embodiment 2. In Fig. 9, the same reference numerals as in Fig. 3 indicate the same or corresponding parts, and detailed description thereof will be omitted. Fig. 10 is a hardware configuration diagram showing the hardware of the radiated electromagnetic noise estimation device 3 according to embodiment 2. In Fig. 10, the same reference numerals as in Fig. 4 indicate the same or corresponding parts, and detailed description thereof will be omitted.

[0036] The necessity determination unit 15 is realized, for example, by a necessity determination circuit 25 shown in FIG. 10 . The necessity determination unit 15 acquires first data from the first data acquisition unit 11, second data from the second data acquisition unit 12, and third data from the third data acquisition unit 13. Based on the first data and the noise test standard value TH, the necessity determination unit 15 determines whether or not measures are necessary to reduce the electromagnetic noise radiated from the evaluation target device EUT when the evaluation target device EUT is installed at a first distance from the first measuring instrument 1. The noise test standard value TH is a standard value adopted in EMC test standards. Specifically, the necessity determination unit 15 calculates a first difference Xf, which is the difference between the peak value Ref_f of the first data and the noise test standard value TH, and calculates a second difference Xn, which is the difference between the peak value Ref_n of the second data and the peak value EUT_n of the third data. The necessity determination unit 15 determines that a measure to deal with radiated electromagnetic noise is necessary if the sum of the first difference Xf and the second difference Xn is smaller than the threshold value Mf, and determines that a measure to deal with radiated electromagnetic noise is not necessary if the sum of the first difference Xf and the second difference Xn is equal to or greater than the threshold value Mf.

[0037] 9 assumes that each of the components of the radiated electromagnetic noise estimation device 3, namely, the first data acquisition unit 11, the second data acquisition unit 12, the third data acquisition unit 13, the noise estimation unit 14, and the necessity determination unit 15, is realized by dedicated hardware such as that shown in Fig. 10. That is, it assumes that the radiated electromagnetic noise estimation device 3 is realized by a first data acquisition circuit 21, a second data acquisition circuit 22, a third data acquisition circuit 23, a noise estimation circuit 24, and a necessity determination circuit 25. Each of the first data acquisition circuit 21, the second data acquisition circuit 22, the third data acquisition circuit 23, the noise estimation circuit 24, and the necessity determination circuit 25 may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof.

[0038] The components of the radiated electromagnetic noise estimation device 3 are not limited to those realized by dedicated hardware, and the radiated electromagnetic noise estimation device 3 may be realized by software, firmware, or a combination of software and firmware. When the radiated electromagnetic noise estimation device 3 is realized by software, firmware, or the like, a program for causing a computer to execute the respective processing procedures of the first data acquisition unit 11, the second data acquisition unit 12, the third data acquisition unit 13, the noise estimation unit 14, and the necessity determination unit 15 is stored in a memory 31 shown in Fig. 5. Then, a processor 32 shown in Fig. 5 executes the program stored in the memory 31.

[0039] 10 shows an example in which each of the components of the radiated electromagnetic noise estimation device 3 is realized by dedicated hardware, while Fig. 5 shows an example in which the radiated electromagnetic noise estimation device 3 is realized by software, firmware, etc. However, this is merely an example, and some of the components in the radiated electromagnetic noise estimation device 3 may be realized by dedicated hardware, and the remaining components may be realized by software, firmware, etc.

[0040] Next, the operation of the radiated electromagnetic noise estimation device 3 shown in FIG. 9 will be described. Since the radiated electromagnetic noise estimation device 3 is the same as the radiated electromagnetic noise estimation device 3 shown in FIG. 3 except for the necessity determination unit 15, only the operation of the necessity determination unit 15 will be described here. The necessity determination unit 15 acquires first data from the first data acquisition unit 11 and acquires the peak value Ref_f of the first data from the noise estimation unit 14. A noise test standard value TH is recorded in the internal memory of the necessity determination unit 15. However, this is merely an example, and the noise test standard value TH may be provided from outside the radiated electromagnetic noise estimation device 3. The necessity determination unit 15 calculates a first difference Xf, which is the difference between the peak value Ref_f of the first data and the noise test standard value TH, as shown in the following equation (3): 11 is an explanatory diagram showing the first difference Xf, which is the difference between the peak value Ref_f of the first data and the noise test standard value TH. Here, the necessity determination unit 15 acquires the peak value Ref_f of the first data from the noise estimation unit 14. However, this is merely an example, and the necessity determination unit 15 may also perform processing to identify the peak value Ref_f of the first data.

[0041] The necessity determination unit 15 obtains the second data from the second data obtaining unit 12 and the third data from the third data obtaining unit 13. The necessity determination unit 15 calculates a second difference, which is the difference Xn between the peak value Ref_n of the second data and the peak value EUT_n of the third data, as shown in the following equation (4): Xn [dB] = Ref_n [dBuV / m] - EUT_n [dBuV / m] (4) Here, the necessity determination unit 15 calculates the second difference Xn. However, this is merely an example, and the necessity determination unit 15 may obtain the difference Xn from the noise estimation unit 14.

[0042] The necessity determination unit 15 determines that a measure to deal with radiated electromagnetic noise is necessary if the sum of the first difference Xf and the second difference Xn is smaller than the threshold value Mf, as shown in the following equation (5): Mf [dB] > Xf [dB] + Xn [dB] (5) The necessity determination unit 15 determines that a measure to deal with radiated electromagnetic noise is not necessary if the sum of the first difference Xf and the second difference Xn is equal to or greater than the threshold value Mf. The determination result of the necessity determination unit 15 is displayed, for example, on a display device (not shown).

[0043] In the second embodiment described above, the radiated electromagnetic noise estimation device 3 is configured to include a necessity determination unit 15 that determines whether or not measures are necessary for the radiated electromagnetic noise of the evaluation target device based on the first data, the second data, the third data, and the noise test standard value when the evaluation target device is installed at a position separated by a first distance from the first measuring device 1. Therefore, the radiated electromagnetic noise estimation device 3 can estimate the radiated electromagnetic noise of the evaluation target device even without a simple measurement site, and can also inform the user whether or not measures are necessary for the radiated electromagnetic noise of the evaluation target device.

[0044] Third Embodiment In a third embodiment, a radiated electromagnetic noise estimation device 3 in which the necessity determining unit 16 corrects the second difference Xn will be described.

[0045] Fig. 12 is a configuration diagram showing a radiated electromagnetic noise estimation device 3 according to embodiment 3. In Fig. 12, the same reference numerals as in Fig. 3 and Fig. 9 indicate the same or corresponding parts, and detailed description thereof will be omitted. Fig. 13 is a hardware configuration diagram showing the hardware of the radiated electromagnetic noise estimation device 3 according to embodiment 3. In Fig. 13, the same reference numerals as in Fig. 4 and Fig. 10 indicate the same or corresponding parts, and detailed description thereof will be omitted.

[0046] The necessity determination unit 16 is realized by, for example, a necessity determination circuit 26 shown in FIG. 13. The necessity determination unit 16 determines a frequency f corresponding to the peak value Ref_n of the second data. Ｒｅｆ and the frequency f corresponding to the peak value EUT_n of the third data ＥＵＴ If different from the frequency f Ｒｅｆand the frequency f corresponding to the peak value EUT_n of the third data ＥＵＴ The second difference Xn is corrected based on the calculated value Ref_f. The necessity determination unit 16 calculates a first difference Xf, which is the difference between the peak value Ref_f of the first data and the noise test standard value TH, and determines that a measure to deal with radiated electromagnetic noise is necessary if the sum of the first difference Xf and the corrected second difference Xn' is smaller than the threshold value Mf. The necessity determination unit 16 determines that a measure to deal with radiated electromagnetic noise is not necessary if the sum of the first difference Xf and the corrected second difference Xn' is equal to or greater than the threshold value Mf.

[0047] 12 assumes that each of the components of the radiated electromagnetic noise estimation device 3, namely, the first data acquisition unit 11, the second data acquisition unit 12, the third data acquisition unit 13, the noise estimation unit 14, and the necessity determination unit 16, is realized by dedicated hardware such as that shown in Fig. 13. That is, it is assumed that the radiated electromagnetic noise estimation device 3 is realized by a first data acquisition circuit 21, a second data acquisition circuit 22, a third data acquisition circuit 23, a noise estimation circuit 24, and a necessity determination circuit 26. Each of the first data acquisition circuit 21, the second data acquisition circuit 22, the third data acquisition circuit 23, the noise estimation circuit 24, and the necessity determination circuit 26 may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof.

[0048] The components of the radiated electromagnetic noise estimation device 3 are not limited to those realized by dedicated hardware, and the radiated electromagnetic noise estimation device 3 may be realized by software, firmware, or a combination of software and firmware. When the radiated electromagnetic noise estimation device 3 is realized by software, firmware, or the like, a program for causing a computer to execute the respective processing procedures of the first data acquisition unit 11, the second data acquisition unit 12, the third data acquisition unit 13, the noise estimation unit 14, and the necessity determination unit 16 is stored in a memory 31 shown in Fig. 5. Then, a processor 32 shown in Fig. 5 executes the program stored in the memory 31.

[0049] 13 shows an example in which each of the components of the radiated electromagnetic noise estimation device 3 is realized by dedicated hardware, while Fig. 5 shows an example in which the radiated electromagnetic noise estimation device 3 is realized by software, firmware, etc. However, this is merely an example, and some of the components in the radiated electromagnetic noise estimation device 3 may be realized by dedicated hardware, and the remaining components may be realized by software, firmware, etc.

[0050] Next, the operation of the radiated electromagnetic noise estimation device 3 shown in FIG. 12 will be described. Since the radiated electromagnetic noise estimation device 3 is the same as the radiated electromagnetic noise estimation device 3 shown in FIG. 9 except for the necessity determination unit 16, only the operation of the necessity determination unit 16 will be described here. The necessity determination unit 16 acquires first data from the first data acquisition unit 11 and acquires the peak value Ref_f of the first data from the noise estimation unit 14. A noise test standard value TH is recorded in the internal memory of the necessity determination unit 16. However, this is merely an example, and the noise test standard value TH may be provided from outside the radiated electromagnetic noise estimation device 3. Similar to the necessity determination unit 15 shown in FIG. 9 , the necessity determination unit 16 calculates a first difference Xf, which is the difference between the peak value Ref_f of the first data and the noise test standard value TH, as shown in Equation (3).

[0051] The necessity determination unit 16 obtains the second data from the second data obtaining unit 12 and obtains the third data from the third data obtaining unit 13. Similar to the necessity determination unit 15 shown in FIG. 9 , the necessity determination unit 16 calculates a second difference, which is the difference Xn between the peak value Ref_n of the second data and the peak value EUT_n of the third data, as shown in Equation (4). Here, the necessity determination unit 16 calculates the second difference Xn. However, this is merely an example, and the necessity determination unit 16 may obtain the difference Xn from the noise estimation unit 14.

[0052] As shown in FIG. 14, the necessity determining unit 16 determines the frequency f corresponding to the peak value Ref_n of the second data. Ｒｅｆ and the frequency f corresponding to the peak value EUT_n of the third data ＥＵＴ When the frequency f is different from the frequency f, as shown in the following equation (6), Ｒｅｆand frequency f ＥＵＴ The second difference Xn is corrected based on the above. Xn' is the corrected second difference. Xn' [dB] = Xn [dB] - 20 × log (f Ｒｅｆ / f ＥＵＴ ) (6) Figure 14 is an explanatory diagram showing the relationship between the near field strength of radiated electromagnetic noise and frequency. In Figure 14, the solid line shows the radiated electromagnetic noise of the device under evaluation EUT when the device under evaluation EUT is installed at a position a second distance away from the second measuring device 2. The dashed line shows the radiated electromagnetic noise of the reference device Ref when the reference device Ref is installed at a position a second distance away from the second measuring device 2.

[0053] The necessity determination unit 16 determines that a measure to deal with radiated electromagnetic noise is necessary if the sum of the first difference Xf and the corrected second difference Xn' is smaller than the threshold value Mf, as shown in the following equation (7): Mf [dB] > Xf [dB] + Xn' [dB] (7) The necessity determination unit 16 determines that a measure to deal with radiated electromagnetic noise is not necessary if the sum of the first difference Xf and the corrected second difference Xn' is equal to or greater than the threshold value Mf. The determination result of the necessity determination unit 16 is displayed, for example, on a display device (not shown).

[0054] In the third embodiment described above, the necessity determination unit 16 corrects the second difference based on the frequency corresponding to the peak value of the second data and the frequency corresponding to the peak value of the third data when the frequency corresponding to the peak value of the second data differs. The necessity determination unit 16 determines that a measure to reduce radiated electromagnetic noise is necessary if the sum of the first difference and the corrected second difference is smaller than a threshold, and determines that a measure to reduce radiated electromagnetic noise is unnecessary if the sum of the first difference and the corrected second difference is equal to or greater than the threshold. Therefore, the radiated electromagnetic noise estimation device 3 can estimate the radiated electromagnetic noise of the device to be evaluated even without a simple measurement site. Furthermore, even when the frequency corresponding to the peak value of the second data differs from the frequency corresponding to the peak value of the third data, the radiated electromagnetic noise estimation device 3 can inform the user whether a measure to reduce radiated electromagnetic noise of the device to be evaluated is necessary.

[0055] In the radiated electromagnetic noise estimation device 3 shown in FIG. 12, the necessity determination unit 16 determines whether or not the frequency f Ｒｅｆ and frequency f ＥＵＴ However, this is merely an example, and the noise estimation unit 14 of the radiated electromagnetic noise estimation device 3 shown in FIG. Ｒｅｆ and the frequency f corresponding to the peak value EUT_n of the third data ＥＵＴ If they are different, the difference Xn may be corrected as shown in the following equation (6'). Xn' is the difference after correction. Xn' [dB] = Xn [dB] - 20 × log (f Ｒｅｆ / f ＥＵＴ ) (6') In this case, the noise estimation unit 14 estimates the radiated electromagnetic noise EUT_f of the device under evaluation EUT by substituting the corrected difference Xn' into equation (2) instead of the difference Xn.

[0056] Fourth Embodiment In a fourth embodiment, a radiated electromagnetic noise estimation device 3 in which the necessity determining unit 17 corrects the second difference Xn will be described.

[0057] Fig. 15 is a configuration diagram showing a radiated electromagnetic noise estimation device 3 according to embodiment 4. In Fig. 15, the same reference numerals as those in Figs. 3, 9, and 12 indicate the same or corresponding parts, and detailed descriptions thereof will be omitted. Fig. 16 is a hardware configuration diagram showing the hardware of the radiated electromagnetic noise estimation device 3 according to embodiment 4. In Fig. 16, the same reference numerals as those in Figs. 4, 10, and 13 indicate the same or corresponding parts, and detailed descriptions thereof will be omitted.

[0058] The necessity determiner 17 is realized by, for example, a necessity determination circuit 27 shown in FIG. 16 . When the measurement position corresponding to the peak value Ref_n of the second data and the measurement position corresponding to the peak value EUT_n of the third data are different, the necessity determiner 17 corrects the second difference Xn based on the measurement position corresponding to the peak value Ref_n of the second data and the measurement position corresponding to the peak value EUT_n of the third data. The necessity determiner 17 calculates a first difference Xf, which is the difference between the peak value Ref_f of the first data and the noise test standard value TH, and determines that a measure against radiated electromagnetic noise is necessary if the sum of the first difference Xf and the corrected second difference Xn″ is smaller than a threshold Mf. The necessity determiner 17 determines that a measure against radiated electromagnetic noise is not necessary if the sum of the first difference Xf and the corrected second difference Xn″ is equal to or greater than the threshold Mf.

[0059] 15 assumes that each of the components of the radiated electromagnetic noise estimation device 3, namely, the first data acquisition unit 11, the second data acquisition unit 12, the third data acquisition unit 13, the noise estimation unit 14, and the necessity determination unit 17, is realized by dedicated hardware such as that shown in Fig. 16. That is, it is assumed that the radiated electromagnetic noise estimation device 3 is realized by a first data acquisition circuit 21, a second data acquisition circuit 22, a third data acquisition circuit 23, a noise estimation circuit 24, and a necessity determination circuit 27. Each of the first data acquisition circuit 21, the second data acquisition circuit 22, the third data acquisition circuit 23, the noise estimation circuit 24, and the necessity determination circuit 27 may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof.

[0060] The components of the radiated electromagnetic noise estimation device 3 are not limited to those realized by dedicated hardware, and the radiated electromagnetic noise estimation device 3 may be realized by software, firmware, or a combination of software and firmware. When the radiated electromagnetic noise estimation device 3 is realized by software, firmware, or the like, a program for causing a computer to execute the respective processing procedures of the first data acquisition unit 11, the second data acquisition unit 12, the third data acquisition unit 13, the noise estimation unit 14, and the necessity determination unit 17 is stored in a memory 31 shown in Fig. 5. Then, a processor 32 shown in Fig. 5 executes the program stored in the memory 31.

[0061] 16 shows an example in which each of the components of the radiated electromagnetic noise estimation device 3 is realized by dedicated hardware, while Fig. 5 shows an example in which the radiated electromagnetic noise estimation device 3 is realized by software, firmware, etc. However, this is merely an example, and some of the components in the radiated electromagnetic noise estimation device 3 may be realized by dedicated hardware, and the remaining components may be realized by software, firmware, etc.

[0062] Next, the operation of the radiated electromagnetic noise estimation device 3 shown in FIG. 15 will be described. Since the radiated electromagnetic noise estimation device 3 is the same as the radiated electromagnetic noise estimation device 3 shown in FIG. 9 except for the necessity determination unit 17, only the operation of the necessity determination unit 17 will be described here. The necessity determination unit 17 acquires first data from the first data acquisition unit 11 and acquires the peak value Ref_f of the first data from the noise estimation unit 14. A noise test standard value TH is recorded in the internal memory of the necessity determination unit 17. However, this is merely an example, and the noise test standard value TH may be provided from outside the radiated electromagnetic noise estimation device 3. Similar to the necessity determination unit 15 shown in FIG. 9 , the necessity determination unit 17 calculates a first difference Xf, which is the difference between the peak value Ref_f of the first data and the noise test standard value TH, as shown in Equation (3).

[0063] The necessity determination unit 17 obtains the second data from the second data obtaining unit 12 and obtains the third data from the third data obtaining unit 13. Similar to the necessity determination unit 15 shown in FIG. 9 , the necessity determination unit 17 calculates a second difference, which is the difference Xn between the peak value Ref_n of the second data and the peak value EUT_n of the third data, as shown in Equation (4). Here, the necessity determination unit 17 calculates the second difference Xn. However, this is merely an example, and the necessity determination unit 17 may obtain the difference Xn from the noise estimation unit 14.

[0064] 17 is an explanatory diagram showing the measurement position corresponding to the peak value Ref_n of the second data and the measurement position corresponding to the peak value EUT_n of the third data. When the measurement position corresponding to the peak value Ref_n of the second data is, for example, x0 and the measurement position corresponding to the peak value EUT_n of the third data is, for example, x3, and these measurement positions are different, the necessity determiner 17 corrects the second difference Xn based on the measurement position x0 and the measurement position x3, as shown in the following equation (8). Xn" is the corrected second difference. Xn" [dB] = Xn [dB] - (Ag_Ref [dBi] - Ag_EUT [dBi]) (8) In equation (8), Ag_Ref is the antenna gain at the measurement position x0, and Ag_EUT is the antenna gain at the measurement position x3.

[0065] The necessity determination unit 17 determines that a measure to deal with radiated electromagnetic noise is necessary if the sum of the first difference Xf and the corrected second difference Xn" is smaller than the threshold value Mf, as shown in the following equation (9): Mf [dB] > Xf [dB] + Xn" [dB] (9) The necessity determination unit 17 determines that a measure to deal with radiated electromagnetic noise is not necessary if the sum of the first difference Xf and the corrected second difference Xn" is equal to or greater than the threshold value Mf. The determination result of the necessity determination unit 17 is displayed, for example, on a display device not shown.

[0066] In the above-described fourth embodiment, when the measurement position of the radiated electromagnetic noise corresponding to the peak value of the second data differs from the measurement position of the radiated electromagnetic noise corresponding to the peak value of the third data, the necessity determination unit 17 corrects the second difference based on the measurement position of the radiated electromagnetic noise corresponding to the peak value of the second data and the measurement position of the radiated electromagnetic noise corresponding to the peak value of the third data. The necessity determination unit 17 is configured to determine that a measure to deal with radiated electromagnetic noise is necessary if the sum of the first difference and the corrected second difference is smaller than a threshold, and to determine that a measure to deal with radiated electromagnetic noise is unnecessary if the sum of the first difference and the corrected second difference is equal to or greater than the threshold. Therefore, the radiated electromagnetic noise estimation device 3 can estimate the radiated electromagnetic noise of the evaluation target device even without a simple measurement site. Furthermore, it can notify the user whether a measure to deal with radiated electromagnetic noise of the evaluation target device is necessary even if the measurement position corresponding to the peak value of the second data differs from the measurement position corresponding to the peak value of the third data.

[0067] 15 , the necessity determination unit 17 corrects the second difference Xn based on the measurement position x0 and the measurement position x3. However, this is merely an example, and the noise estimation unit 14 of the radiated electromagnetic noise estimation device 3 shown in FIG. 3 may correct the difference Xn as shown in the following equation (8′) when the measurement position x0 corresponding to the peak value Ref_n of the second data and the measurement position x3 corresponding to the peak value EUT_n of the third data are different. Xn″ is the corrected difference. Xn″ [dB] = Xn [dB] - (Ag_Ref [dBi] - Ag_EUT [dBi]) (8′) In this case, the noise estimation unit 14 estimates the radiated electromagnetic noise EUT_f of the device to be evaluated EUT by substituting the corrected difference Xn″ into equation (2) instead of the difference Xn.

[0068] Embodiment 5. In embodiment 5, the range of horizontal radiated electromagnetic noise measured by the second measuring device 2 will be described. FIG. 18 is an explanatory diagram showing the measurement position of horizontal radiated electromagnetic noise by the second measuring device 2. In FIG. 18, ● indicates the measurement position of radiated electromagnetic noise by the second measuring device 2. This measurement position is a third distance away from the respective positions where the reference device Ref and the evaluation target device EUT are installed toward the second measuring device 2. The third distance is the proximity measurement distance dn. ld indicates the measurement range of radiated electromagnetic noise in a direction perpendicular to the direction from each of the reference device Ref and the evaluation target device EUT toward the second measuring device 2, and in a direction horizontal to the respective installation surfaces of the reference device Ref and the evaluation target device EUT. The measurement range ld of radiated electromagnetic noise in the horizontal direction is determined from the azimuth angle θ of radiated electromagnetic noise measurable by the second measuring device 2 and the proximity measurement distance dn, as shown in the following equation (10): θ [deg] = 2 × tan －１ (ld / 2dn) (10)

[0069] To measure radiated electromagnetic noise at an azimuth angle of 360 degrees according to the EMC test, it is necessary to rotate the device under evaluation (EUT) 360 / θ times to acquire data. Therefore, the azimuth angle θ is determined based on the number of times the radiated electromagnetic noise is actually measured, and the measurement range ld of the radiated electromagnetic noise is determined from the azimuth angle θ and the proximity measurement distance dn, as shown in equation (10). Figure 19 is an explanatory diagram showing the relationship between ld / dn and the azimuth angle θ.

[0070] FIG. 20 is an explanatory diagram showing the measurement position of radiated electromagnetic noise in the vertical direction by the second measuring device 2. FIG. 21 is an explanatory diagram showing the relationship between the installation positions of the reference device Ref and the device under evaluation EUT and the proximity measurement element 2a of the second measuring device 2. In FIGS. 20 and 21 , ● indicates the measurement position of radiated electromagnetic noise by the second measuring device 2. This measurement position is a third distance away from the installation positions of the reference device Ref and the device under evaluation EUT toward the second measuring device 2. The third distance is the proximity measurement distance dn. hd indicates the measurement range of radiated electromagnetic noise in a direction perpendicular to the direction from each of the reference device Ref and the device under evaluation EUT toward the second measuring device 2 and perpendicular to the installation surfaces of the reference device Ref and the device under evaluation EUT. The measurement range hd of radiated electromagnetic noise in the vertical direction is determined from the elevation angles φ1 and φ3 and the proximity measurement distance dn, as shown in the following equation (11). hd=hd_h+hd_l=dn×tan(φ1)+dn×tan(φ3) (11) FIG. 22 is an explanatory diagram showing the relationship between the proximity measurement distance dn and the measurement ranges hd_h and hd_l of radiated electromagnetic noise in the vertical direction.

[0071] In addition, the present disclosure allows for free combination of the respective embodiments, modification of any of the components of the respective embodiments, or omission of any of the components of the respective embodiments.

[0072] The present disclosure can estimate the radiated electromagnetic noise of an evaluation target device even without a simple measurement site, and can be used in a radiated electromagnetic noise estimation device and a radiated electromagnetic noise estimation method.

[0073] 1 First measuring device, 1a Far-field measurement antenna, 2 Second measuring device, 2a Proximity measurement element, 3 Radiation electromagnetic noise estimation device, 11 First data acquisition unit, 12 Second data acquisition unit, 13 Third data acquisition unit, 14 Noise estimation unit, 15, 16, 17 Necessity determination unit, 21 First data acquisition circuit, 22 Second data acquisition circuit, 23 Third data acquisition circuit, 24 Noise estimation circuit, 25, 26, 27 Necessity determination circuit, 31 Memory, 32 Processor.

Claims

1. A radiated electromagnetic noise estimation device comprising: a first data acquisition unit that acquires first data, which is data obtained by measuring the radiated electromagnetic noise of a reference device using a first measuring device when the reference device is installed at a first distance from the first measuring device; a second data acquisition unit that acquires second data, which is data obtained by measuring the radiated electromagnetic noise of the reference device using a second measuring device when the reference device is installed at a second distance that is shorter than the first distance from the second measuring device; a third data acquisition unit that acquires third data, which is data obtained by measuring the radiated electromagnetic noise of an evaluation target device using the second measuring device when the evaluation target device is installed at the second distance from the second measuring device; and a noise estimation unit that estimates the radiated electromagnetic noise of the evaluation target device when the evaluation target device is installed at the first distance from the first measuring device, from the first data, the second data, and the third data.

2. A radiated electromagnetic noise estimation device as described in claim 1, characterized in that it is equipped with a necessity determination unit that determines whether or not measures are necessary to deal with radiated electromagnetic noise from the evaluation target device when the evaluation target device is installed at a position separated by the first distance from the first measuring device, based on the first data, the second data, the third data, and noise test standard values.

3. The radiated electromagnetic noise estimation device according to claim 2, characterized in that the necessity determination unit calculates a first difference which is the difference between the peak value of the first data and the noise test standard value, and calculates a second difference which is the difference between the peak value of the second data and the peak value of the third data, and determines that measures against the radiated electromagnetic noise are necessary if the sum of the first difference and the second difference is smaller than a threshold value, and determines that measures against the radiated electromagnetic noise are not necessary if the sum of the first difference and the second difference is equal to or greater than the threshold value.

4. The radiated electromagnetic noise estimation device according to claim 3, characterized in that the necessity determination unit, when the frequency corresponding to the peak value of the second data and the frequency corresponding to the peak value of the third data are different, corrects the second difference based on the frequency corresponding to the peak value of the second data and the frequency corresponding to the peak value of the third data, determines that measures against the radiated electromagnetic noise are necessary if the sum of the first difference and the corrected second difference is smaller than a threshold value, and determines that measures against the radiated electromagnetic noise are not necessary if the sum of the first difference and the corrected second difference is equal to or greater than the threshold value.

5. The radiated electromagnetic noise estimation device according to claim 3, characterized in that the necessity determination unit, when the measurement position of the radiated electromagnetic noise corresponding to the peak value of the second data and the measurement position of the radiated electromagnetic noise corresponding to the peak value of the third data are different, corrects the second difference based on the measurement position of the radiated electromagnetic noise corresponding to the peak value of the second data and the measurement position of the radiated electromagnetic noise corresponding to the peak value of the third data, determines that measures against the radiated electromagnetic noise are necessary if the sum of the first difference and the corrected second difference is smaller than a threshold value, and determines that measures against the radiated electromagnetic noise are not necessary if the sum of the first difference and the corrected second difference is equal to or greater than the threshold value.

6. A radiated electromagnetic noise estimation device as described in any one of claims 1 to 5, characterized in that the noise estimation unit calculates the difference between the peak value of the second data and the peak value of the third data, and uses the peak value of the first data and this difference to estimate the radiated electromagnetic noise of the evaluation target device when the evaluation target device is installed at a position separated by the first distance from the first measuring instrument.

7. The radiated electromagnetic noise estimation device according to claim 6, characterized in that, when the frequency corresponding to the peak value of the second data and the frequency corresponding to the peak value of the third data are different, the noise estimation unit corrects the difference based on the frequency corresponding to the peak value of the second data and the frequency corresponding to the peak value of the third data, and uses the peak value of the first data and the corrected difference to estimate the radiated electromagnetic noise of the evaluation target device when the evaluation target device is installed at a position separated by the first distance from the first measuring instrument.

8. The radiated electromagnetic noise estimation device of claim 6, characterized in that, when the measurement position of the radiated electromagnetic noise corresponding to the peak value of the second data is different from the measurement position of the radiated electromagnetic noise corresponding to the peak value of the third data, the noise estimation unit corrects the difference based on the measurement position of the radiated electromagnetic noise corresponding to the peak value of the second data and the measurement position of the radiated electromagnetic noise corresponding to the peak value of the third data, and uses the peak value of the first data and the corrected difference to estimate the radiated electromagnetic noise of the evaluation target equipment when the evaluation target equipment is installed at a position separated by the first distance from the first measuring instrument.

9. A radiated electromagnetic noise estimation device as described in any one of claims 1 to 8, characterized in that at a position a third distance away from the positions where the reference equipment and the evaluation target equipment are installed toward the second measuring instrument, a measurement range of radiated electromagnetic noise in a direction perpendicular to the direction from the reference equipment and the evaluation target equipment toward the second measuring instrument and in a direction horizontal to the installation surfaces of the reference equipment and the evaluation target equipment is determined by the third distance, and the radiated electromagnetic noise within the measurement range is measured by the second measuring instrument.

10. A radiated electromagnetic noise estimation device as described in any one of claims 1 to 8, characterized in that at a position a third distance away from the positions where the reference equipment and the evaluation target equipment are installed toward the second measuring instrument, a measurement range of radiated electromagnetic noise in a direction perpendicular to the direction from each of the reference equipment and the evaluation target equipment toward the second measuring instrument and in a direction perpendicular to the installation surface of each of the reference equipment and the evaluation target equipment is determined by the third distance, and radiated electromagnetic noise within the measurement range is measured by the second measuring instrument.

11. A radiated electromagnetic noise estimation device as described in any one of claims 1 to 10, characterized in that the measurement of the radiated electromagnetic noise relating to each of the second data and the third data by the second measuring instrument is performed at a position where the measurement frequency of the radiated electromagnetic noise satisfies the far-field condition.

12. A radiated electromagnetic noise estimation method, in which a first data acquisition unit acquires first data, which is data obtained by measuring the radiated electromagnetic noise of a reference device using a first measuring device when the reference device is installed at a position separated by a first distance from the first measuring device; a second data acquisition unit acquires second data, which is data obtained by measuring the radiated electromagnetic noise of the reference device using a second measuring device when the reference device is installed at a second distance shorter than the first distance from the second measuring device; a third data acquisition unit acquires third data, which is data obtained by measuring the radiated electromagnetic noise of an evaluation target device using the second measuring device when the evaluation target device is installed at the second distance from the second measuring device; and a noise estimation unit estimates the radiated electromagnetic noise of the evaluation target device when it is installed at the first distance from the first measuring device, from the first data, the second data, and the third data.

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