Program, information processing method, and information processing apparatus

Abstract

To provide a program capable of accurately estimating a distribution of electromagnetic field intensity of a radiation disturbance wave on a virtual surface enclosing a sample while suppressing an increase of time to be required in a radiation disturbance wave test on the radiation disturbance wave having a frequency included in a wider frequency band.SOLUTION: A program allows a computer to perform a first calculation step of calculating an upper limit value of a measurement interval of a radiation disturbance wave of an antenna based on positions of a plurality of electromagnetic wave sources corresponding to the sample to radiate the radiation disturbance wave and also relative position relationship between the antenna for measuring the radiation disturbance wave and the sample.SELECTED DRAWING: Figure 12

Description

[Technical Field]

[0001] This disclosure relates to a program, an information processing method, and an information processing apparatus. [Background technology]

[0002] Research and development are being conducted on techniques used to perform radiation interference testing. Here, radiation interference testing is a test that verifies whether the electric field strength of the electromagnetic waves radiated as radiation interference from a test specimen is below the permissible value of internationally established standards. The test specimen is the object to which radiation interference testing is performed. The test specimen is also an object that contains an electromagnetic wave source that radiates radiation interference. For example, the test specimen is an electronic device. When the test specimen is an electronic device, radiation interference testing is often performed before the electronic device is shipped to the market. This is because radiation interference emitted from the electronic device can affect other electronic devices in the surrounding area, for example, causing malfunctions in those other electronic devices.

[0003] In radiation interference testing, the distribution of the target electric field strength on a predetermined measurement surface is estimated as the target electric field strength distribution. The measurement surface is a hypothetical surface surrounding the test specimen. After the target electric field strength distribution is estimated, the radiation interference test identifies the position where the target electric field strength is maximum, based on the estimated target electric field strength distribution, as the maximum electric field strength position. After the maximum electric field strength position is identified, the radiation interference test measures the target electric field strength at the identified maximum electric field strength position for a predetermined time. Then, after the target electric field strength has been measured at the maximum electric field strength position for the predetermined time, the radiation interference test verifies whether the peak value, integral value, average value, etc., of the target electric field strength measured at the maximum electric field strength position for the predetermined time are below the permissible values ​​of internationally established standards.

[0004] In radiation interference testing, multiple measurement points are set on the measurement surface to estimate the target electric field strength distribution. Each of these measurement points is designated as a measurement location, and the target electric field strength is measured at each location. The target electric field strength distribution is then estimated based on the electric field strengths measured at each location. The accuracy of the estimated target electric field strength distribution is expressed by the degree of agreement between the location of the maximum electric field strength in the estimated distribution and the actual location of the maximum electric field strength in the actual distribution. Therefore, high estimation accuracy of the target electric field strength distribution indicates high accuracy in identifying the location of the maximum electric field strength.

[0005] Thus, in radiation interference testing, the target electric field strength is measured at each measurement location. Therefore, in radiation interference testing, the accuracy of estimating the target electric field strength distribution increases with the number of measurement points set on the measurement surface. However, the time required to estimate the target electric field strength distribution increases with the number of measurement points set on the measurement surface.

[0006] For example, in radiation interference testing for information and communication equipment in the frequency band (i.e., 30MHz to 40GHz), the shape of the measurement surface is cylindrical. In this radiation interference test, multiple measurement points are set on the measurement surface at 1cm intervals vertically on the cylindrical surface, with a height of 1m to 4m from the reference plane. Furthermore, in this radiation interference test, multiple measurement points are set on the measurement surface at 1° intervals circumferentially on the cylindrical surface, with an azimuth angle of 0° to 360° around the central axis of the cylindrical surface. As a result, the number of measurement points set on the measurement surface in this radiation interference test reaches approximately 140,000. Consequently, even if, for example, one minute of measurement is taken at each measurement point, this radiation interference test would take more than 140,000 minutes (approximately 97 days).

[0007] Furthermore, in radiation interference testing, it is necessary to broaden the frequency bandwidth of the electromagnetic waves measured as radiation interference in order to improve the accuracy of estimating the electric field strength distribution of the target. For this reason, radiation interference testing measures the spectrum of the electromagnetic waves by using a spectrum analyzer, such as a superheterodyne spectrum analyzer or an FFT (Fast Fourier Transform) spectrum analyzer. However, it is known that the time required for radiation interference testing increases as the frequency bandwidth of the electromagnetic waves widens.

[0008] Thus, in radiation interference testing, if the goal is to achieve high accuracy in estimating the electric field strength distribution of the target field, the time required for radiation interference testing can become longer.

[0009] Herein, in order to suppress the increase in the time required for such radiation interference tests, there is a known radiation interference measuring device that has an electromagnetic wave measurement point calculation device that calculates multiple measurement positions on the measurement surface based on the sampling theorem, and performs radiation interference tests based on the multiple measurement positions calculated by the electromagnetic wave measurement point calculation device (see Patent Documents 1 and 2). [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Japanese Patent Publication No. 2017-181104 [Patent Document 2] Japanese Patent Publication No. 2020-159905 [Overview of the project] [Problems that the invention aims to solve]

[0011] The radiation interference measuring device described in Patent Documents 1 and 2, given a measurement position Y1, calculates the measurement interval as the distance from measurement position Y1 to the next measurement position Y2 based on the sampling theorem. Then, the radiation interference measuring device calculates measurement position Y2 based on the calculated measurement interval and measurement position Y1. The radiation interference measuring device performs this calculation of measurement positions one by one sequentially for each measurement position, and based on the calculated multiple measurement positions, it identifies the arrangement of multiple measurement positions on the measurement surface, that is, the arrangement of multiple measurement points set on the measurement surface. As a result, the radiation interference measuring device can accurately estimate the electric field strength distribution of the target without unnecessarily increasing the number of measurement points to be set.

[0012] However, with the radiation interference measurement devices described in Patent Documents 1 and 2, the measurement accuracy of the target electric field strength distribution may deteriorate as the distance between the test specimen and the measurement point approaches the wavelength of the radiation interference. In other words, with these radiation interference measurement devices, the measurement accuracy may deteriorate as the frequency of the radiation interference decreases. This is because the radiation interference measurement device increases the measurement interval based on the sampling theorem as the frequency of the radiation interference decreases. Furthermore, Patent Documents 1 and 2 do not show the relationship between the distance between the test specimen and the measurement point, the wavelength of the radiation interference, and the measurement accuracy. This is undesirable because it may lead to measuring the target electric field strength distribution using a measurement interval shorter than the one calculated by the radiation interference measurement device in order to suppress the deterioration of the measurement accuracy. In such cases, the user of the radiation interference measurement device will unnecessarily increase the measurement time of the target electric field strength distribution.

[0013] This disclosure has been made in consideration of these circumstances, and aims to provide a program, an information processing method, and an information processing device that can accurately estimate the distribution of electromagnetic field strength of radiated interference waves on a virtual surface surrounding a test specimen, while suppressing the increase in the time required for radiated interference wave testing for radiated interference waves having frequencies included in a wider frequency band. [Means for solving the problem]

[0014] One aspect of this disclosure is a program that causes a computer to perform a first calculation step of causing the computer to calculate an upper limit value for the measurement interval of the radiated interference waves by an antenna, based on the positions of a plurality of electromagnetic wave sources corresponding to a test specimen that radiates radiated interference waves and the relative positional relationship between an antenna that measures the radiated interference waves and the test specimen.

[0015] Furthermore, one aspect of this disclosure is an information processing method having a first calculation step of calculating an upper limit value for the measurement interval of the radiated interference waves by the antenna, based on the positions of a plurality of electromagnetic wave sources corresponding to a test specimen that radiates radiated interference waves and the relative positional relationship between the antenna that measures the radiated interference waves and the test specimen.

[0016] Furthermore, one aspect of the present disclosure is an information processing device comprising a first calculation unit that calculates an upper limit value for the measurement interval of the radiated interference waves by the antenna, based on the positions of a plurality of electromagnetic wave sources corresponding to a test specimen that radiates radiated interference waves, and the relative positional relationship between the antenna that measures the radiated interference waves and the test specimen. [Effects of the Invention]

[0017] According to this disclosure, it is possible to accurately estimate the distribution of electromagnetic field intensity of radiated interference waves on a virtual surface surrounding the test specimen, while suppressing the increase in the time required for radiated interference wave testing for radiated interference waves with frequencies included in a wider frequency band. [Brief explanation of the drawing]

[0018] [Figure 1] This figure shows an example of the configuration of a radiation interference measurement device 100 according to an embodiment. [Figure 2] This is an illustrative diagram showing an example of how multiple measurement points are set on a measurement surface. [Figure 3]This figure shows an example of the positional relationship between the test specimen 1 and the antenna 2 in an anechoic chamber where the radiation interference measurement device 100 is installed. [Figure 4] This figure shows an example of the functional configuration of computer 7. [Figure 5] This figure shows an example of the hardware configuration of computer 7. [Figure 6] This figure shows an example of the flow of the measurement point placement identification process performed by the radiation interference measurement device 100. [Figure 7] This figure shows an example of the flow of the position identification process in step S140, as shown in Figure 6. [Figure 8] This figure shows an example of the positional relationship between two electromagnetic wave sources located within the electromagnetic wave source region and an observation point positioned on the circumference of the measurement circle. [Figure 9] This figure shows an example of spatial frequency spectra corresponding to each of the multiple measured target electric field strength distributions estimated by the target estimation method, when the frequency of the radiated interference wave coincides with a certain frequency. [Figure 10] This figure shows an example of the relationship between the measurement interval of radiated interference waves and the frequency of the radiated interference waves, corresponding to the maximum spatial frequency of each radiated interference wave frequency. [Figure 11] Figure 10 shows an example of how the spatial frequency spectrum value changes in response to a change in the analysis ratio when the value on the horizontal axis of the graph shown is 0.001. [Figure 12] This figure shows an example of the process flow for the radiation interference measurement device 100 to calculate the upper limit of the measurement interval for radiation interference. [Figure 13] This figure shows an example of the process flow in which the radiation interference measurement device 100 estimates the target electric field strength distribution using the upper limit of the measurement interval for radiation interference. [Figure 14] This figure compares the measured electric field strength distribution estimated by the flowchart shown in Figure 13 based on certain measurement conditions with the actual measured electric field strength distribution estimated by simulations based on those measurement conditions and electromagnetism. [Modes for carrying out the invention]

[0019] <Embodiment> The embodiments of this disclosure will be described below with reference to the drawings.

[0020] <Configuration of Radiation Interference Measurement Device> The configuration of the radiation interference measuring device 100 according to this embodiment will be described below with reference to Figure 1. Figure 1 is a diagram showing an example of the configuration of the radiation interference measuring device 100 according to this embodiment.

[0021] The radiated interference measurement device 100 is a device for performing radiated interference tests. Radiated interference tests are tests that measure radiated interference emitted from a test specimen in accordance with EMC (ElectroMagnetic Compatibility) standards. For this reason, the test conditions and test methods for radiated interference tests are internationally defined. Furthermore, a radiated interference test is a test in which at least one of the electric field strength and magnetic field strength of the radiated interference is measured as a measurement of radiated interference. Below, as an example, we will describe the case in which a radiated interference test is a test in which the electric field strength of the radiated interference is measured. Also, for the sake of explanation below, the electric field strength of the radiated interference measured by the radiated interference measurement device 100 in a radiated interference test will be referred to as the measured electric field strength.

[0022] Here, the test specimen is an object containing an electromagnetic wave source that emits radiated interference waves. The test specimen is also the object subject to the radiated interference wave test (i.e., the subject of the radiated interference wave test). Furthermore, radiated interference waves are electromagnetic waves within a predetermined frequency band emitted from the test specimen. Below, as an example, we will describe the case where such a test specimen is Test Specimen 1 shown in Figure 1. In this case, the radiated interference wave measuring device 100 performs a radiated interference wave test to measure the radiated interference waves emitted from Test Specimen 1. Therefore, for the sake of explanation, the radiated interference waves emitted from Test Specimen 1 will be simply referred to as radiated interference waves. Also, in this example, Test Specimen 1 is a notebook PC (Personal Computer). Note that Test Specimen 1 may be replaced with other electronic devices, communication equipment, etc., that emit electromagnetic waves.

[0023] The radiation interference measurement device 100 is placed in an anechoic chamber equipped with a metal floor surface forming a ground plane. A radio wave absorber may or may not be installed on the ground plane. The radio wave absorber is a material that absorbs radiation interference, and is made using, for example, magnetic materials or carbon. Furthermore, a radio wave absorber may or may not be attached to the inner walls of the anechoic chamber, excluding the metal floor surface. The following describes, as an example, a case where no radio wave absorber is installed on the ground plane. Also, the following describes, as an example, a case where no radio wave absorber is attached to the wall surface.

[0024] Furthermore, the radiation interference measuring device 100 includes an antenna 2, an antenna mast 3, a turntable 4, a receiver 5, a controller 6, and a computer 7. The radiation interference measuring device 100 may also include other devices, equipment, or components in addition to the antenna 2, antenna mast 3, turntable 4, receiver 5, controller 6, and computer 7. In addition, the computer 7 in the radiation interference measuring device 100 may be integrated with either the receiver 5 or the controller 6, or both.

[0025] Antenna 2 can be any antenna capable of detecting the electric field strength of electromagnetic waves. In the example shown in Figure 1, antenna 2 is a hybrid antenna supported by an antenna mast 3. Antenna 2 outputs an electrical signal indicating a voltage corresponding to the detected electric field strength to a receiver 5, which will be described later. In this embodiment, as an example, the position of antenna 2 is described in which the position of the tip of antenna 2 is represented. However, the position of antenna 2 may be represented by another position corresponding to antenna 2, such as a reference point for antenna calibration, instead of the position of the tip.

[0026] The antenna mast 3 can be any antenna mast that is capable of moving the antenna 2 along a desired direction in response to control by the controller 6, which will be described later. In the example shown in Figure 1, the antenna mast 3 is an antenna mast that is capable of moving the antenna 2 along the vertical direction. This allows the radiation interference measurement device 100 to move the relative position of the antenna 2 with respect to the test specimen 1 along the vertical direction.

[0027] Because it is supported by such an antenna mast 3, in this embodiment, the position of the antenna 2 changes along the vertical direction by the antenna mast 3, but does not change along directions other than the vertical direction. For this reason, in this embodiment, the position of the antenna 2 is represented by the position of the tip of the antenna 2 in the vertical direction, that is, the height of the tip of the antenna 2 from the metal floor surface in the anechoic chamber. Here, in this embodiment, the vertical direction is two directions parallel to the direction of gravity. If the metal floor surface of the anechoic chamber is perpendicular to the direction of gravity, then the vertical direction can also be rephrased as two directions perpendicular to the metal floor surface. More specifically, in this embodiment, the upward direction is the direction opposite to the direction of gravity, of the two directions parallel to the direction of gravity. Also, in this embodiment, the downward direction is the direction that coincides with the direction of gravity, of the two directions parallel to the direction of gravity.

[0028] The turntable 4 is a table that includes a platform on which the test specimen 1 is placed during radiation interference testing. The turntable 4 can be any object that can rotate the test specimen 1 placed on the platform around a predetermined axis of rotation in response to control by the controller 6, which will be described later. This allows the radiation interference measuring device 100 to rotate the position of the antenna 2 relative to the test specimen 1 around the axis of rotation of the turntable 4. Here, the rotation of the position of the antenna 2 relative to the test specimen 1 means, in other words, that the position of the antenna rotates relative to the azimuth angle around the axis of rotation of the turntable 4. In this embodiment, as an example, the case in which the axis of rotation of the turntable 4 is an axis parallel to the vertical direction will be described, as shown in Figure 1. However, the axis of rotation of the turntable 4 may be an axis not parallel to the vertical direction.

[0029] Receiver 5 is connected to computer 7 via wired or wireless connection for communication. Receiver 5 receives electrical signals output from antenna 2. Receiver 5 outputs the received electrical signals to computer 7.

[0030] Controller 6 is a control device that controls the translation of the antenna 2 by the antenna mast 3 and the rotation of the test specimen 1 by the turntable 4. Controller 6 is connected to the antenna mast 3 and the turntable 4 via wire, for example, to enable communication. Controller 6 may control at least one of the antenna mast 3 and the turntable 4 in response to a request from the computer 7, or it may control at least one of the antenna mast 3 and the turntable 4 based on an operation received from the user. The following describes the case in which Controller 6 controls both the antenna mast 3 and the turntable 4 in response to a request from the computer 7.

[0031] Computer 7 is, for example, a notebook PC. However, Computer 7 may be replaced with other information processing devices such as a desktop PC or a tablet PC.

[0032] Computer 7 controls the controller 6 and receiver 5 to perform radiated interference testing. More specifically, computer 7 sets two or more measurement points on a predetermined measurement surface. The measurement surface is a virtual surface surrounding the test specimen 1. Each of the two or more measurement points is a virtual point set at each of two or more measurement positions on the measurement surface where the target electric field strength is measured. In other words, each of the two or more measurement points is a virtual point that represents each of the measurement positions on the measurement surface. That is, the position of a certain measurement point set on the measurement surface is the measurement position that the measurement point indicates. After setting two or more measurement points on the measurement surface, computer 7 controls the controller 6 to sequentially match the position of antenna 2 with the position of each of the two or more measurement points set on the predetermined measurement surface. Each time the position of antenna 2 is matched with the measurement position indicated by each of the two or more measurement points set on the measurement surface, computer 7 controls receiver 5 to acquire the electrical signal output from receiver 5. This electrical signal corresponds to the electric field strength detected by antenna 2 at the measurement position where antenna 2 is located. Furthermore, when computer 7 acquires an electrical signal from receiver 5, it calculates the electric field strength corresponding to the acquired electrical signal as the target electric field strength. For example, computer 7 calculates the target electric field strength corresponding to the acquired electrical signal based on information relating the magnitude of the electrical signal to the magnitude of the electric field strength. In a radiated interference test, computer 7 calculates the target electric field strength at the measurement positions indicated by each of the two or more measurement points set on the measurement surface through this process. In this embodiment, measuring the target electric field strength means that computer 7 calculates the target electric field strength based on the electrical signal acquired from receiver 5 in this way. That is, in a radiated interference test, computer 7 measures the target electric field strength at the measurement positions indicated by each of the two or more measurement points set on the measurement surface through this process.

[0033] In a radiated interference test, after measuring the target electric field strength at each of the two or more measurement points set on the measurement surface, the computer 7 estimates the distribution of the target electric field strength on the measurement surface as the target electric field strength distribution, based on the target electric field strength measured at each measurement position. The method for estimating the target electric field strength distribution may be a known method such as applying a low-pass filter, or it may be a method to be developed in the future. The target electric field strength distribution is a distribution that shows the position where the target electric field strength is maximum as the first estimated maximum electric field strength position. Therefore, the estimation accuracy of the target electric field strength distribution estimated by the computer 7 is expressed by the degree of agreement between the first estimated maximum electric field strength position shown by the estimated target electric field strength distribution and the actual maximum electric field strength position shown by the actual target electric field strength distribution. Therefore, the high estimation accuracy of the target electric field strength distribution indicates the high accuracy of identifying the first estimated maximum electric field strength position.

[0034] In the radiated interference test, after estimating the target electric field strength distribution, the computer 7 identifies the first estimated maximum electric field strength location based on the estimated target electric field strength distribution.

[0035] In the radiation interference test, after identifying the first estimated maximum electric field strength location, the computer 7 aligns the identified first maximum electric field strength location with the position of antenna 2 and measures the target electric field strength for a predetermined time. The computer 7 then determines whether the peak value, integral value, average value, etc., of the target electric field strength measured for the predetermined time are below the permissible values ​​of internationally established standards. In this way, the radiation interference measuring device 100 performs the radiation interference test. The computer 7 may be configured to display information indicating the determination result on a display unit that is not illustrated (for example, a display), or it may be configured to output the information indicating the result to another device.

[0036] Furthermore, before conducting such radiation interference tests, the computer 7 identifies the arrangement of two or more measurement points to be used in the radiation interference test, that is, the arrangement of two or more measurement positions on the measurement surface, as described below.

[0037] Before conducting radiation interference tests, computer 7 receives tolerance information indicating permissible values ​​in response to user input. Here, this tolerance indicates the acceptable magnitude of deviation from the second estimated maximum electric field strength position. The tolerance may be expressed in units of distance, for example, or in decibels. Below, as an example, the case where the tolerance is expressed in decibels will be explained. The second estimated maximum electric field strength position is the position estimated by a predetermined estimation method as the actual maximum electric field strength position mentioned above. The predetermined estimation method is, for example, theoretical calculation based on electromagnetism, numerical simulation, or measurement experiment conducted in advance, but is not limited to these. The second estimated maximum electric field strength position may be considered as a type of theoretical value for the position where the measured electric field strength is maximum.

[0038] Furthermore, before conducting the radiation interference test, the computer 7 receives measurement condition information in response to the user's input. Here, the measurement condition information is information indicating the measurement conditions for measuring radiation interference in the radiation interference test. For example, the measurement condition information includes information that includes test specimen information about the test specimen 1, measurement space information about the measurement space where radiation interference is measured, and radiation interference information about the radiation interference, as information indicating the measurement conditions. Note that the measurement condition information may also include other information in addition to this information.

[0039] The specimen information includes information that indicates the size of the specimen 1, such as the distance from the rotation axis of the turntable 4 to the part of the specimen 1 placed on the turntable 4 in the radial direction, with the radius being the distance from the rotation axis of the turntable 4 to the part of the specimen 1 that is farthest from the rotation axis of the turntable 4, the height of a cylindrical region with the rotation axis of the turntable 4 as its central axis, and the radius of said cylindrical region. In this embodiment, the radial direction of the turntable 4 is parallel to the horizontal direction. The horizontal direction is perpendicular to the direction of gravity. For the sake of explanation, this region will be referred to as the electromagnetic wave source region below. The specimen information may also include other information about the specimen 1. Furthermore, the radial direction of the turntable 4 may be parallel to a direction different from the horizontal direction. Also, the shape of the electromagnetic wave source region may be other shapes such as a rectangular parallelepiped instead of a cylindrical shape.

[0040] The measurement space information includes, for example, measurement range information that indicates the range within which the tip of antenna 2 can be moved vertically, as information related to the measurement space. The measurement space information may also include other information related to the measurement space.

[0041] Radiated interference information includes, for example, wavelength information indicating the wavelength of the radiated interference, information indicating the frequency of the radiated interference, and so on. The radiated interference information may also include other information related to the radiated interference.

[0042] Furthermore, before conducting the radiation interference test, the computer 7 sets the measurement surface according to the operation received from the user, as described above. In this embodiment, as an example, we will describe the case where the measurement surface is a virtual cylindrical surface that has the central axis of the electromagnetic wave source region as its central axis and encompasses the entire electromagnetic wave source region. For this reason, the measurement surface is a surface that represents the set of points (i.e., positions in which the tip of the antenna 2 can be positioned) that the tip of the antenna 2 can be positioned by the rotation of the turntable 4, the vertical movement of the tip of the antenna 2, etc. Note that if the radiation interference measuring device 100 is equipped with a mechanism that allows the position of the tip of the antenna 2 to be moved in the horizontal direction, the measurement surface may be a virtual surface of another shape in which the tip of the antenna 2 can be positioned.

[0043] After receiving tolerance value information and measurement condition information, and setting the measurement surface, the computer 7 identifies the arrangement of two or more measurement points to be set on the set measurement surface, that is, the arrangement of two or more measurement positions, based on the tolerance value indicated by the received tolerance value information and the received measurement condition information. Here, this arrangement is determined by the measurement interval of the radiated interference. More specifically, the computer 7 calculates the measurement interval of the radiated interference based on the tolerance value and the measurement condition information, and identifies the arrangement based on the calculated measurement interval of the radiated interference. Here, the measurement interval of the radiated interference is the interval between adjacent measurement points among the two or more measurement points. In other words, the measurement interval of the radiated interference is the interval between adjacent measurement positions among the two or more measurement positions. The computer 7 identifies this arrangement by executing a measurement point arrangement identification process. The measurement point arrangement identification process is a process in which the computer 7 identifies the arrangement of two or more measurement points based on the measurement condition information received, the tolerance value information, and the sampling theorem. Furthermore, the measurement point placement determination process may also refer to the process of determining the placement of two or more measurement points based on the measurement condition information received by the computer 7 and the sampling theorem. Also, the measurement point placement determination process may be any process that includes a process capable of calculating the measurement interval of radiated interference waves based on the sampling theorem. Below, as an example, we will describe a case where the measurement point placement determination process includes the first, second, and third processes described below.

[0044] The first process involves identifying the arrangement of two or more measurement points based on the value of a measurement interval adjustment parameter, which adjusts the measurement interval of radiated interference waves, and the measurement condition information received by the computer 7. The measurement interval adjustment parameter is a parameter whose value is decreased each time the third process, described later, is executed. Details of the measurement interval adjustment parameter will be described later.

[0045] Here, the method by which the computer 7 identifies the arrangement of two or more measurement points in the first process may be any method.

[0046] For example, computer 7 identifies the arrangement of two or more measurement points in the first process by the method described below. This method is one of several known methods by which computer 7 can identify the arrangement of two or more measurement points.

[0047] First, the computer 7 sets up multiple virtual points on a pre-defined measurement surface, and calculates the position of each of these virtual points on the measurement surface based on the set virtual points, the measurement condition information received in advance, and the value of the measurement interval adjustment parameter mentioned above. For the sake of explanation, in the following, each of the multiple virtual points on the measurement surface will be simply referred to as a virtual point.

[0048] Here, there are multiple methods for the computer 7 to calculate the position of each of the multiple virtual points. In this embodiment, as an example, we will describe a method in which the computer 7 calculates the position of each of the multiple virtual points by setting up multiple parallel virtual lines that extend in a predetermined direction along the measurement surface, and for each of the set multiple virtual lines, the computer 7 calculates the position of each of the multiple virtual points that are lined up on the virtual line. In this embodiment, as an example, we will describe a case where the predetermined direction is parallel to the vertical direction. In this embodiment, as an example, we will describe a case where the multiple virtual lines are arranged at equal intervals on the measurement surface. That is, in this embodiment, as an example, we will describe a case where the multiple virtual lines are parallel to the central axis of the cylindrical measurement surface and are arranged at equal intervals in the circumferential direction of the cylinder on the cylindrical measurement surface. Note that the method for the computer 7 to calculate the position of each of the multiple virtual points may be other methods. In addition, the predetermined direction may be parallel to other directions such as the horizontal direction or the circumferential direction of the measurement surface (i.e., the azimuth direction mentioned above) instead of the vertical direction. In addition, some or all of the multiple virtual lines do not have to be arranged at equal intervals on the measurement surface.

[0049] For the sake of simplicity, the following explanation will use the example of the computer 7 calculating the position of multiple virtual points by describing the process of calculating the position of multiple virtual points arranged on one of multiple virtual lines. Therefore, the single virtual line will be referred to as the "target line" below. Also, for the sake of convenience, each of the multiple virtual points arranged on the target line will be referred to as a "target point". Furthermore, the positions of the multiple target points can be represented by their height in the vertical direction, unless the specimen 1 rotates. Therefore, for the sake of convenience, the height of each of the multiple target points in the vertical direction will be referred to as the position of each of the multiple target points. The principle by which the computer 7 calculates the position of each of the multiple target points based on the value of the measurement interval adjustment parameter will be described later.

[0050] After calculating the position of each of the multiple target points, the computer 7 identifies the positions of each of the two or more measurement points to be set on the target line, that is, the measurement positions indicated by each of the two or more measurement points set on the target line, based on the calculated positions of each of the multiple target points, as the arrangement of the two or more measurement points to be set on the target line. Furthermore, each time the computer 7 selects each of the multiple virtual lines that are parallel to each other and extend in a predetermined direction along the measurement surface as the target line, it identifies the positions of each of the two or more measurement points to be set on the target line in this manner. In this way, the computer 7 can identify the arrangement of all measurement points that indicate the positions where radiated interference waves are measured. For the sake of explanation below, each of the two or more measurement points set on the target line will be referred to as a target measurement point.

[0051] The first process is to identify the arrangement of two or more measurement points using the method described above.

[0052] The second process, if the arrangement of two or more measurement points is determined by the first process, involves estimating the distribution of the target electric field strength on the measurement surface based on the arrangement of the two or more measurement points determined by the first process, and calculating the first estimated maximum electric field strength position based on the estimated distribution of the target electric field strength. The first estimated maximum electric field strength position can be considered as a type of experimental value for the maximum electric field strength position. In other words, the aforementioned tolerance value can be rephrased as a value indicating the acceptable magnitude of the deviation between the first estimated maximum electric field strength position and the second estimated maximum electric field strength position.

[0053] The third process is to reduce the value of the measurement interval adjustment parameter and execute the first process again if the difference between the first estimated maximum electric field strength position calculated in the second process and the second estimated maximum electric field strength position exceeds the tolerance value indicated by the tolerance value information received by the computer 7.

[0054] Here, the intervals between adjacent target points among the aforementioned multiple target points are associated with a measurement interval adjustment parameter. That is, the intervals between adjacent target points among the multiple target points change according to the value of the measurement interval adjustment parameter. In other words, the function that represents the intervals between adjacent target points among the multiple target points includes the measurement interval adjustment parameter. Therefore, in the third process, the computer 7 can reduce the intervals between adjacent target points among the multiple target points by reducing the value of the measurement interval adjustment parameter. And as the intervals between adjacent target points among the multiple target points become smaller, the intervals between adjacent target measurement points among the two or more target measurement points identified by the computer 7 in the first process also become smaller. That is, in the third process, the computer 7 can reduce the intervals between adjacent target measurement points among the two or more target measurement points identified by the computer 7 by reducing the value of the measurement interval adjustment parameter. Then, in the third process, if the difference between the first estimated maximum electric field strength position and the second estimated maximum electric field strength position calculated in the second process is less than or equal to the tolerance value indicated by the tolerance value information received by the computer 7, the computer 7 identifies the positions of each of the two or more target measurement points identified in the first process as an arrangement of two or more target measurement points. This also prevents the computer 7 from making the spacing between adjacent target measurement points too small. As a result, the computer 7 can accurately estimate the target electric field strength distribution while suppressing an increase in the time required for radiation interference testing.

[0055] As described above, in the measurement point placement identification process, the computer 7 executes the first to third processes, repeatedly identifying the placement of two or more measurement points while decreasing the value of the measurement interval adjustment parameter until the difference between the first estimated maximum electric field strength position and the second estimated maximum electric field strength position becomes less than or equal to the tolerance value indicated by the tolerance value information received by the computer 7. For this reason, the value given as the initial value of the measurement interval adjustment parameter is the maximum value that the measurement interval adjustment parameter can take. The maximum value that the measurement interval adjustment parameter can take will be described later. In this way, the value of the measurement interval adjustment parameter decreases by a predetermined value each time the third process is performed. Consequently, the more times the third process is performed, the shorter the distance between measurement points in the placement of two or more measurement points identified by the first and second processes becomes.

[0056] However, the arrangement of two or more measurement points identified by this measurement point arrangement identification process can worsen the measurement accuracy of the target electric field strength distribution as the distance between the test specimen 1 and the measurement points (i.e., the distance between the test specimen 1 and antenna 2) approaches the wavelength of the radiated interference wave. In other words, the lower the frequency of the radiated interference wave, the worse the measurement accuracy can become. This is because, as the frequency of the radiated interference wave decreases, the measurement point arrangement identification process increases the distance between two adjacent measurement points among the two or more measurement points, i.e., the measurement interval for the radiated interference wave, based on the sampling theorem. Furthermore, the relationship between the distance between the test specimen 1 and the measurement points, the wavelength of the radiated interference wave, and the measurement accuracy has never been clearly demonstrated. This is undesirable because it could lead to using a shorter interval than the one calculated by the measurement point arrangement identification process as the measurement interval for the radiated interference wave in order to suppress the deterioration of measurement accuracy. In such cases, the user of the radiation interference measurement device 100 will unnecessarily increase the measurement time for the target electric field strength distribution.

[0057] Therefore, the computer 7 calculates an upper limit for the measurement interval of radiated interference waves by the antenna 2, based on the positions of multiple electromagnetic wave sources corresponding to the test specimen 1 that emits radiated interference waves, and the relative positional relationship between the antenna 2 that measures the radiated interference waves and the test specimen 1. As a result, the computer 7 can select the calculated upper limit as the measurement interval for radiated interference waves in the low-frequency band, and select the measurement interval for radiated interference waves calculated by the measurement point placement determination process as the measurement interval for radiated interference waves actually used in the radiated interference wave measurement test in the high-frequency band. More specifically, if the maximum value of the measurement interval for radiated interference waves calculated by the measurement point placement determination process exceeds the calculated upper limit, the computer 7 can select the calculated upper limit as the measurement interval for radiated interference waves. If the maximum value of the measurement interval for radiated interference waves calculated by the measurement point placement determination process is less than or equal to the calculated upper limit, the computer 7 can select the measurement interval for radiated interference waves calculated by the measurement point placement determination process. As a result, when the frequency of the radiated interference is low, computer 7 can suppress the unnecessary increase in the measurement interval of the radiated interference based on the sampling theorem. In other words, computer 7 can accurately estimate the measured electric field strength distribution while suppressing the increase in the time required for radiated interference testing for radiated interference with frequencies included in a wider frequency band.

[0058] After selecting the measurement interval for radiated interference in this manner, the computer 7 sets measurement points at the positions of two or more measurement points identified based on the selected measurement interval for radiated interference. The measurement surface is associated with the test specimen 1 so as to rotate together with the test specimen 1, which rotates on the turntable 4. Therefore, the relative position of each measurement point set on the measurement surface with respect to the test specimen 1 does not change even when the test specimen 1 rotates.

[0059] The following section will provide a detailed explanation of the functional and hardware configuration of computer 7, as well as the process by which computer 7 identifies the positions of two or more measurement points.

[0060] Figure 2 is an illustrative diagram showing an example of how multiple measurement points are set on a measurement surface. The surface 17 shown in Figure 2 is an example of a hypothetical surface. Each of the multiple "○"s shown in Figure 2 represents an example of one of the multiple measurement points set on the hypothetical surface, without overlap. The multiple measurement points included in the range 18 shown in Figure 2 represent an example of multiple target measurement points.

[0061] <Positional relationship between the test specimen and the antenna in an anechoic chamber where radiation interference measurement equipment is installed> The positional relationship between the test specimen 1 and the antenna 2 in the anechoic chamber where the radiation interference measurement device 100 is installed will be explained below with reference to Figure 3. Figure 3 is a diagram showing an example of the positional relationship between the test specimen 1 and the antenna 2 in the anechoic chamber where the radiation interference measurement device 100 is installed. Note that this positional relationship is also the positional relationship between the test specimen 1 and each of several target points set on a certain target line. In the following explanation, in order to simplify the explanation, the shape of the test specimen 1 will be described as cylindrical, as shown in Figure 3. In this embodiment, the height refers to the length in the direction perpendicular to the metal floor surface of the anechoic chamber, that is, in the direction of gravity.

[0062] In the example shown in Figure 3, the position of a certain target point MP coincides with the position of antenna 2. In this example, the range in which the computer 7 moves the position of antenna 2 vertically during the radiation interference test is a height range of 1m to 4m. For the sake of explanation, below, the lower limit of the height within the range in which the computer 7 moves the position of antenna 2 vertically during the radiation interference test will be referred to as the lower measurement limit position. Also, for the sake of explanation, below, the upper limit of the height within this range will be referred to as the upper measurement limit position. In this example, the lower measurement limit position is 1m. Also, in this example, the upper measurement limit position is 4m. The aforementioned measurement range is the range from this lower measurement limit position to the upper measurement limit position. In other words, the measurement range is the range in which the antenna mast 3 moves the position of antenna 2 along the target line during the radiation interference test.

[0063] As mentioned above, the arrangement of two or more target measurement points is determined based on the position of each of the multiple target points. More specifically, some or all of the multiple target points are identified as two or more target measurement points. That is, if all of the multiple target points are identified as two or more target measurement points, the arrangement of the multiple target points will coincide with the arrangement of two or more target measurement points. For these reasons, the target point MP shown in Figure 3 is one of the candidate target measurement points.

[0064] Furthermore, as shown in Figure 3, for the sake of explanation below, the shortest distance from the tip of antenna 2 to test specimen 1 in the horizontal direction (parallel to the metal floor surface of the anechoic chamber) will be denoted as d min This is shown by [the formula shown]. Also, for the sake of explanation below, the longest distance in the horizontal direction from the tip of antenna 2 to the test specimen 1 will be [the formula shown]. max This is shown by [the formula]. Also, for the sake of explanation below, the height of the bottom surface of specimen 1 will be given as h min This is shown by [the formula]. Also, for the sake of explanation below, the height of the top surface of specimen 1 will be given as h max This is shown by [the following]. And, for the sake of explanation, the height of the position of antenna 2 will be h rx This is shown by [the method].

[0065] <Functional Configuration of Computer 7> The following describes the functional configuration of computer 7 with reference to Figure 4. Figure 4 is a diagram showing an example of the functional configuration of computer 7. In addition to the configuration of computer 7, Figure 4 also shows the antenna 2, antenna mast 3, turntable 4, receiver 5, and controller 6.

[0066] Computer 7 comprises a control unit 8 and an arithmetic processing unit 9. Computer 7 may also have other functional configurations.

[0067] The control unit 8 controls the entire computer 7. Furthermore, for example, the control unit 8 controls a controller 6 that is communicatively connected to the computer 7. Also, for example, it controls a receiver 5 that is communicatively connected to the computer 7.

[0068] The arithmetic processing unit 9 performs various calculations in the radiation interference test conducted by the radiation interference measurement device 100. For example, the arithmetic processing unit 9 calculates the target electric field strength based on the electrical signal acquired from the receiver 5. Also, for example, the arithmetic processing unit 9 calculates the position of each of the multiple target points.

[0069] <Hardware configuration of Computer 7> The hardware configuration of computer 7 will be described below with reference to Figure 5. Figure 5 is a diagram showing an example of the hardware configuration of computer 7.

[0070] Computer 7 comprises a main control unit 10, an input device 11, an output device 12, a storage device 13, and a bus 14 connecting these to each other. Computer 7 may also be configured to include other hardware in addition to these.

[0071] The main control unit 10 has a CPU (Central Processing Unit) and RAM (Random Access Memory). The main control unit 10 executes various programs stored in the storage device 13 and realizes the various functional configurations of the computer 7, including the aforementioned control unit 8 and arithmetic processing unit 9.

[0072] The input device 11 is a device that receives input from the user, such as a keyboard, mouse, or touchpad. The input device 11 may also be integrated with the output device 12 to form a touch panel.

[0073] The output device 12 is a device that displays various types of information output by the computer 7. For example, the output device 12 includes a display unit (e.g., a display) of the computer 7 (not shown).

[0074] The storage device 13 is a device that stores various types of information, various images, various programs executed by the main control unit 10, etc. The storage device 13 may be, for example, a hard disk drive, an optical disk drive, or a flash memory device. The storage device 13 includes a recording medium 15 on which various types of information are written. The storage device 13 writes (records) various types of information to the recording medium 15 in response to a request from the main control unit 10. The storage device 13 also reads various types of information from the recording medium 15 in response to a request from the main control unit 10 and outputs the read information to the main control unit 10. For example, the recording medium 15 contains programs that implement the control unit 8 and the arithmetic processing unit 9, respectively.

[0075] <Calculation principle for the position of each of multiple target points> The following explains the principle for calculating the position of each of the multiple target points. Note that the principle for calculating the position of each of the multiple target points is based on the sampling theorem.

[0076] First, the radiated interference emitted from the test object 1 is not emitted from only one point of the substance constituting the test object 1. Therefore, in the following description, it is assumed that the test object 1 is a collection of P point-shaped electromagnetic wave sources that emit electromagnetic waves as radiated interference. Further, in the following description, it is assumed that electromagnetic waves of the same frequency and the same wavelength are emitted from the P electromagnetic wave sources as radiated interference. P may be any integer as long as it is an integer of 2 or greater. Let r be the distance from the p-th electromagnetic wave source among the P electromagnetic wave sources to the position of a certain hypothetical point (e.g., a target point, a target measurement point, etc.) p , where p is an integer between 1 and P. Further, in the following description, for convenience of explanation, the hypothetical point is referred to as an observation point.

[0077] The electric field intensity generated by the radiated interference emitted from the p-th electromagnetic wave source at a position separated by a distance r p from the electromagnetic wave source can be represented by a plane wave as shown in the following formula (1).

[0078] [Mathematical expression]

[0079] Here, each of a p and b p shown in formula (1) is a parameter corresponding to the radiated interference emitted from the p-th electromagnetic wave source at a distance r pThis coefficient represents the amplitude of the plane wave that produces the electric field strength at a distance, and is a real number. Also, i in equation (1) is the imaginary unit. Also, k in equation (1) represents the wavenumber of the radiated interference wave emitted from each of the P electromagnetic wave sources. The wavenumber of the radiated interference wave is the number of times that one wavelength of the radiated interference wave is contained within a unit length, when one wavelength of the radiated interference wave is counted as one wave. The wavenumber of the radiated interference wave is also the value obtained by dividing 2π by the wavelength of the radiated interference wave. Since the electric field strength can be expressed as in equation (1), the electric field strength produced at the observation point by the radiated interference waves emitted from each of the P electromagnetic wave sources is expressed by the superposition of the plane waves shown in equation (1) above, as shown in equation (2) below.

[0080]

number

[0081] Therefore, the square of the electric field strength generated at the observation point by the radiated interference waves emitted from each of the P electromagnetic wave sources is calculated as shown in equation (3) below.

[0082]

number

[0083] Here, the r shown in equation (3) q This represents the distance from the q-th electromagnetic wave source out of the P electromagnetic wave sources to the observation point. q is an integer from 1 to P, and may be the same integer as p or a different integer from p. As can be seen from the right-hand side of the bottom row of equation (3), the square of the electric field strength produced at the observation point by the radiated interference waves emitted from each of the P electromagnetic wave sources is (r p -r q This is the sum of sinusoidal waves oscillating with respect to ). From this, it can be seen that the distribution of electric field strength of radiated interference waves emitted from P electromagnetic sources can be perfectly reproduced by satisfying the conditions shown in equation (4) below, based on the sampling theorem.

[0084]

number

[0085] Here, λ shown in equation (4) is the wavelength of the electromagnetic wave emitted as radiated interference wave from each electromagnetic wave source. Also, Δ(r) shown in equation (4) p -r q ) is (r p -r q This shows the infinitesimal change in ). The condition obtained as equation (4) in this way can be rephrased as a condition that must be satisfied for the interval between two adjacent target points among multiple target points, by the method described below.

[0086] The height of the p-th electromagnetic wave source is h p This is shown by the distance from the electromagnetic wave source to the observation point in the horizontal direction, which is d. p As shown by, the distance r p The position h of the observation point rx Using this, it can be expressed as equation (5) below by the Pythagorean theorem.

[0087]

number

[0088] Also, the height of the q-th electromagnetic wave source is h q This is shown by the distance from the electromagnetic wave source to the observation point in the horizontal direction, which is d. q As shown by, the distance r q The position h of the observation point rx Using this, it can be expressed as follows by the Pythagorean theorem: (6).

[0089]

number

[0090] Furthermore, if the frequency range of the radiated interference waves emitted from each of the P electromagnetic wave sources is 30 MHz to 1000 MHz, the radiated interference wave test is stipulated to be performed on the metal floor surface of the anechoic chamber. Therefore, in this case, the height h p and height h q Considering the mirror image principle, it can take either a positive or negative value. Also, as an example, the height h is used below. p However, height h q Assume the height is lower than [this value].

[0091] Here, the Δ(r shown in equation (4) above) p -r q ) can be calculated based on equations (5) and (6) as shown in equations (7) and (8) below.

[0092]

number

[0093] Here, in equation (7), the expression obtained by calculating the partial derivative shown in equation (7) is K. h It is defined as follows. For the sake of explanation, K h This will be explained as a correction factor. Correction factor K h The specific expression is shown in equation (8) below.

[0094]

number

[0095] Based on equation (8) and equation (4) above, the condition obtained as equation (4) is the interval Δh between two adjacent target points among multiple target points. rx The conditions that must be satisfied can be rewritten as shown in equation (9) below.

[0096]

number

[0097] Here, the correction coefficient K shown in equation (8) above. h From a geometrical requirement, the following conditions must be met by equations (10) to (13).

[0098]

number

[0099]

number

[0100]

number

[0101]

number

[0102] Based on the conditions in equations (10) to (13) above and the dimensions of the test specimen 1 (in this example, the dimensions of the cylindrical test specimen 1 shown in Figure 3), if the radio wave absorber is installed on the ground plane, the correction coefficient K h The absolute value of K is the largest. hmax The following equation (14) is obtained as a condition for this to occur. Furthermore, based on the conditions in equations (10) to (13) above and the dimensions of the test specimen 1 (in this example, the dimensions of the cylindrical test specimen 1 shown in Figure 3), if no radio wave absorber is installed on the ground plane, then the h in equation (14) min -h max The expression becomes as follows when replaced with this.

[0103]

number

[0104] In this way, one target point is designated as the first target point, another target point adjacent to the first target point is designated as the second target point, and the distance from the first target point to the second target point, that is, the distance between the first target point and the second target point, is given by the K shown in equation (9) above. h K shown in equation (14) hmax It can be calculated as the maximum value obtained by substituting the given value. As a result, the computer 7 can calculate the position of the second target point by adding the calculated interval to the position of the first target point.

[0105] Here, computer 7 uses equation (15), which is an extension of equation (9) above, to calculate the distance between the first target point and the second target point.

[0106]

number

[0107] The S shown in equation (15) is the measurement interval adjustment parameter mentioned above. As shown in equation (15), S is a parameter that is multiplied by the wavelength λ of the radiated interference wave. Therefore, the measurement interval adjustment parameter S can also be rephrased as a parameter that virtually adjusts the wavelength λ of the radiated interference wave. Here, the right-hand side of equation (15) should coincide with the right-hand side of equation (9) above when the measurement interval adjustment parameter S takes its maximum value. This is because equation (9) above satisfies the sampling theorem. Therefore, the initial value of the measurement interval adjustment parameter S shown in equation (15) is 0.50. Of course, if λ is replaced with (λ / 2) in equation (15), the initial value of the measurement interval adjustment parameter becomes 1.00. Computer 7 decreases the value of the measurement interval adjustment parameter S each time the third process is executed. As a result, Computer 7 calculates Δh by equation (15). rxThis can be reduced each time the third process is executed. In other words, the computer 7 can shorten the distance between the first target point and the second target point by reducing the measurement interval adjustment parameter S. That is, the measurement interval adjustment parameter S is an arbitrary parameter added by hand so as to reduce the distance between the first target point and the second target point, within the range that satisfies the conditions of equation (9) above.

[0108] Here, the position of the observation point (i.e., the position of antenna 2) h rx This can be understood as the position of each of the multiple target points. Therefore, the position of the nth target point among the multiple target points is h rx,n This is shown by h rx,n Using equations (14) and (15) above, the position of each of the multiple target points can be calculated by the sequential equation shown in equation (16) below. Note that n is an integer of 1 or more.

[0109]

number

[0110] The h shown in equation (16) rx_min This indicates the position of the lowest point among multiple target points in the vertical direction. rx_min This may be given manually, coincide with the lower limit of measurement, or be determined by other means.

[0111] Here, a radiation interference measuring device different from the radiation interference measuring device 100 (for example, a conventional radiation interference measuring device) uses equations (9), (14), and (16) to calculate the position of each of the multiple target points, and identifies the positions of two or more target measurement points based on the calculated positions of the multiple target points. Then, the radiation interference measuring device estimates the target electric field strength distribution based on the two or more identified target measurement points. However, the radiation interference measuring device may not be able to completely reproduce the target electric field strength distribution due to the filtering process performed when calculating the positions of each of the multiple target points and the extrapolation process at the edges of the multiple measurement points.

[0112] The radiation interference measurement device 100 can solve these problems using equations (14) to (16) above. That is, by using equations (14) to (16) above, the radiation interference measurement device 100 can reproduce the target electric field strength distribution with the estimation accuracy indicated by the pre-accepted tolerance value, i.e., the accuracy desired by the user. In other words, the radiation interference measurement device 100 can reproduce the target electric field strength distribution with the accuracy desired by the user, without reproducing the target electric field strength distribution with a higher accuracy than desired by the user, i.e., with excessive accuracy. As a result, the radiation interference measurement device 100 can accurately estimate the target electric field strength distribution while suppressing an increase in the time required for radiation interference testing. The measurement point placement identification process performed by the radiation interference measurement device 100 will be described below. Specifically, the measurement point arrangement identification process involves the radiation interference measurement device 100 calculating the position of each of the multiple target points for each of the multiple straight lines selected as target lines using the above equations (14) to (16), and then identifying the measurement positions indicated by each of the two or more target measurement points as an arrangement of two or more target measurement points based on the calculated positions. In other words, the measurement point arrangement identification process is the process by which the radiation interference measurement device 100 identifies the arrangement of two or more measurement points.

[0113] <Measurement point location identification process performed by radiation interference measurement device> The following describes the measurement point placement identification process performed by the radiation interference measurement device 100, with reference to Figure 6. Figure 6 is a diagram showing an example of the flow of the measurement point placement identification process performed by the radiation interference measurement device 100. In the following, as an example, we will describe a case where the computer 7 receives an operation to start the measurement point placement identification process at a timing prior to the processing of step S110 shown in Figure 6. That is, in the following, as an example, we will describe a case where the computer 7 sets the measurement surface at that timing. Furthermore, in the following, as an example, we will describe a case where the computer 7 receives tolerance value information indicating the tolerance value desired by the user at that timing, and the tolerance value information received by the computer 7 is stored in the recording medium 15 of the storage device 13. Furthermore, in the following, as an example, we will describe a case where the computer 7 receives measurement condition information at that timing, and the measurement condition information received by the computer 7 is stored in the recording medium 15 of the storage device 13. The measurement condition information includes the above d min d max h min h max The specimen information includes information indicating the upper limit of measurement, the lower limit of measurement, and h rx_min The measurement spatial information that shows and the radiated interference wave information that includes wavelength information that shows the above λ are included at least. Here, h rx_min This refers to the position of the lowest target point among multiple target points, as desired by the user. Furthermore, as an example, the following describes the case in which, at that timing, the computer 7 receives the aforementioned second estimated maximum electric field strength position, and the second estimated maximum electric field strength position information indicating the second estimated maximum electric field strength position received by the computer 7 is stored in the recording medium 15 of the storage device 13.

[0114] After the computer 7 receives the command to start the measurement point placement identification process, the arithmetic processing unit 9 reads out the allowable value information that has been previously stored in the recording medium 15 of the storage device 13 from the storage device 13 (step S110).

[0115] Next, the arithmetic processing unit 9 reads the measurement condition information, which has been previously stored in the recording medium 15 of the storage device 13, from the storage device 13 (step S120).

[0116] Next, the arithmetic processing unit 9 initializes the measurement interval adjustment parameter S (step S130). Specifically, in step S130, the arithmetic processing unit 9 generates a variable to store the value of the measurement interval adjustment parameter S and initializes the value of the generated variable to its initial value. As mentioned above, the initial value of the measurement interval adjustment parameter S is 0.50. That is, in step S130, the arithmetic processing unit 9 stores 0.50 in the variable. For the sake of explanation, this variable will be referred to as the stored variable below. In the flowchart shown in Figure 6, the processes in steps S110, S120, and S130 may be performed in different orders or in parallel.

[0117] Next, the arithmetic processing unit 9 performs a position determination process based on the measurement condition information read in step S120 and the values ​​stored in the storage variables (step S140). The position determination process uses the measurement condition information read in step S120, the values ​​stored in the storage variables, and the above-mentioned equations (14) to (16) to calculate the position of each of the multiple target points for each of the multiple virtual straight lines set on the measurement surface, and then determines the position of each of the two or more target measurement points for each of the straight lines based on the positions calculated for each of the straight lines. Details of the position determination process will be described later. In other words, the position determination process is the process of determining the arrangement of two or more measurement points set on the measurement surface.

[0118] Next, the arithmetic processing unit 9 estimates the electric field strength distribution to be measured based on the arrangement of two or more measurement points identified in step S140. Then, the arithmetic processing unit 9 calculates the first estimated maximum electric field strength position based on the estimated electric field strength distribution to be measured (step S150). Here, the method for estimating the electric field strength distribution to be measured based on the arrangement identified in step S140 may be a known method or a method to be developed in the future. Similarly, the method for calculating the first estimated maximum electric field strength position based on the estimated electric field strength distribution to be measured may be a known method or a method to be developed in the future.

[0119] Next, the arithmetic processing unit 9 determines whether a predetermined determination condition is met based on the first estimated maximum electric field strength position calculated in step S150 (step S160). Here, the predetermined determination condition is that the difference between the second estimated maximum electric field strength position indicated by the second estimated maximum electric field strength position information stored in advance on the recording medium 15 and the first estimated maximum electric field strength position (i.e., the difference between the first estimated maximum electric field strength position and the second estimated maximum electric field strength position is the difference between the first estimated maximum electric field strength position and the second estimated maximum electric field strength position) is less than or equal to the allowable value information read in step S110. That is, in step S160, the arithmetic processing unit 9 calculates the difference as a value expressed in decibels, and if the calculated value is less than or equal to the allowable value, it determines that the predetermined determination condition is met. On the other hand, if the calculated value exceeds the allowable value, the arithmetic processing unit 9 determines that the predetermined determination condition is not met.

[0120] If the arithmetic processing unit 9 determines that the predetermined judgment conditions are not met (step S160-NO), it subtracts a predetermined value from the value of the measurement interval adjustment parameter stored in the storage variable and stores this value in the storage variable as the new value of the measurement interval adjustment parameter. In other words, in this case, the arithmetic processing unit 9 reduces the measurement interval adjustment parameter (step S170). After the processing in step S170 is performed, the arithmetic processing unit 9 transitions to step S140 and performs the position identification process again based on the measurement condition information read in step S120 and the value stored in the storage variable. Here, the predetermined value is, for example, 0.05. Note that the predetermined value may be a value smaller than 0.05 or a value larger than 0.05.

[0121] On the other hand, if the arithmetic processing unit 9 determines that a predetermined determination condition is met (step S160-YES), it generates arrangement information indicating the arrangement of two or more measurement points identified by the last executed step S140, and stores the generated arrangement information in the recording medium 15 of the storage device 13 (step S180). After the process of step S180 is performed, the arithmetic processing unit 9 terminates the process shown in the flowchart in Figure 6.

[0122] Through the measurement point arrangement identification process described above, the computer 7 identifies the arrangement of two or more measurement points that indicate the locations where radiated interference waves will be measured, based on the tolerance values ​​indicated by the received tolerance value information and the received measurement condition information. More specifically, the computer 7 identifies the arrangement of two or more measurement points based on the value of a measurement interval adjustment parameter S which adjusts the distance between measurement points in the arrangement of two or more measurement points and the received measurement condition information. This is done in the following steps: a first process (i.e., the process in step S140) which identifies the arrangement of two or more measurement points based on the value of a measurement interval adjustment parameter S which adjusts the distance between measurement points in the arrangement of two or more measurement points and the received measurement condition information; a second process (i.e., the process in step S150) which, if the arrangement of two or more measurement points is identified by the first process, calculates a first estimated maximum electric field strength position where the intensity of the radiated interference is estimated to be maximum, based on the arrangement of two or more measurement points identified by the first process; and a third process (i.e., the process executed in the order of steps S160, S170, and S140) which, if the difference between the first estimated maximum electric field strength position and the second estimated maximum electric field strength position calculated by the second process exceeds the allowable value, reduces the value of the measurement interval adjustment parameter S and executes the first process.

[0123] <Location determination process performed by radiation interference measurement device> The position identification process of step S140 shown in Figure 6 will now be explained with reference to Figure 7. Figure 7 is a diagram showing an example of the flow of the position identification process of step S140 shown in Figure 6. The computer 7 identifies the arrangement of two or more measurement points by performing the processes of steps S210 to S270 for each of the multiple virtual straight lines set on the measurement surface.

[0124] The arithmetic processing unit 9 generates n as a variable indicating the order of each of the multiple target points. Then, the arithmetic processing unit 9 initializes the generated value of n to its initial value. Below, as an example, the case where the initial value is 1 will be explained. Note that the initial value may be an integer of 2 or greater, or an integer of 0 or less, instead of 1. After initializing the value of n, the arithmetic processing unit 9 selects integers of 1 or greater (i.e., integers greater than or equal to the initial value) in order from 1 (i.e., in order from the initial value) as the value of n, and repeats the processing in steps S220 to S260 for each selected value of n (step S210).

[0125] After the value of n is selected in step S210, the arithmetic processing unit 9 generates a target point corresponding to the currently selected value of n as one of several target points. Hereafter, for the sake of explanation, the target point corresponding to the value of n will be referred to as the first target point. Also, for the sake of explanation, the target point corresponding to the value of (n+1) will be referred to as the second target point. However, at this stage, the arithmetic processing unit 9 does not yet generate the second target point. After generating the first target point, the arithmetic processing unit 9 uses the information contained in the measurement condition information read in step S120 shown in Figure 6 to determine d min d max h min h max Based on each of these, the position of the first target point, the above equation (14), and the sampling theorem, K hmax This is calculated as a correction coefficient corresponding to the first target point (step S220). Here, for the sake of explanation, the position of the first target point in the case of n=1 is h rx,0 This is shown by [the following]. Also, for the sake of explanation below, the position of the first target point in the case of n≧2 will be h rx,n-1 This is shown by [the calculation unit]. Note that when performing the first step S220, the calculation unit 9 performs h based on the measurement condition information read in step S120 shown in Figure 6. rx,0 The position h of the lowest point among multiple target points in the vertical direction. rx_minInitialize to this state. Also, when performing the m-th step S220, the arithmetic processing unit 9 identifies the position of the second target point calculated in the (m-1)th step S240 as the position of the first target point in the m-th step S220. m is an integer greater than or equal to 2.

[0126] For example, when n=1, the arithmetic processing unit 9, in the process of step S220, sets a correction coefficient corresponding to the first target point, K hmax (h rx_min ) is calculated. In this case, the arithmetic processing unit 9 calculates the h indicated by the information included in the measurement condition information in the processing of step S220. min h max d min d max Each of and h rx_min h rx Based on equation (14) after substituting, K hmax (h rx_min ) is calculated as a correction coefficient corresponding to the first target point. Also, for example, if n≧2, the arithmetic processing unit 9 calculates K as a correction coefficient corresponding to the first target point in the process of step S220. hmax (h rx,n-1 ) is calculated. In this case, the arithmetic processing unit 9 calculates the h indicated by the information included in the measurement condition information in the processing of step S220. min h max d min d max Each of and h rx,n-1 h rx Based on equation (14) after substituting, K hmax (h rx,n ) is calculated as a correction coefficient corresponding to the first target point.

[0127] After the processing in step S220 is completed, the arithmetic processing unit 9 uses the measurement condition information read in step S120 shown in Figure 6 and the K calculated as a correction coefficient in step S220. hmax, based on the above formula (15) and the value stored in the current storage variable (i.e., the current value of the measurement interval adjustment parameter S), calculate the interval from the first target point to the second target point as the first interval corresponding to the first target point (step S230). For example, when n=1, the arithmetic processing unit 9, in the process of step S230, obtains Δh as the first interval corresponding to the first target point rx (h rx_min ) is calculated. In this case, in the process of step S230, the arithmetic processing unit 9 calculates K as a correction coefficient corresponding to the first target point based on the value stored in the storage variable hmax (h rx_min ), Δh is obtained as the first interval corresponding to the first target point rx (h rx_min ) is calculated. Further, for example, when n≧2, the arithmetic processing unit 9, in the process of step S230, obtains Δh as the first interval corresponding to the first target point rx (h rx,n-1 ) is calculated. In this case, in the process of step S230, the arithmetic processing unit 9 calculates K as a correction coefficient corresponding to the first target point based on the value stored in the storage variable hmax (h rx,n-1 ), Δh is obtained as the first interval corresponding to the first target point rx (h rx,n-1 ) is calculated.

[0128] Next, the arithmetic processing unit 9 calculates the position of the second target point based on the first interval calculated in step S230 (step S240). For example, when n=1, in step S240, the arithmetic processing unit 9 obtains Δh calculated as the first interval corresponding to the first target point based on the above formula (16) rx (h rx_min ) to h rx_min , the h obtained by addition rx,1 is calculated as the position of the second target point. Further, for example, when N≧2, in step S240, the arithmetic processing unit 9 obtains Δh calculated as the first interval corresponding to the first target point based on the above formula (16) rx (h rx,n-1 ) to h rx,n-1 , the h obtained by addition rx,nThis is calculated as the position of the second target point.

[0129] Next, the arithmetic processing unit 9 determines whether a predetermined termination condition is met (step S250). In this example, the predetermined termination condition is that the position of the second target point calculated in step S240 is outside the measurement range. In this case, in step S250, the arithmetic processing unit 9 determines whether the position of the second target point calculated in step S240 is outside the measurement range based on the measurement condition information read in step S120 shown in Figure 6. Note that the predetermined termination condition may be other conditions.

[0130] If the arithmetic processing unit 9 determines that the predetermined termination condition is not met (step S250-NO), it proceeds to step S210 and selects the next value of n.

[0131] On the other hand, if the arithmetic processing unit 9 determines that a predetermined termination condition has been met (step S250-YES), that is, if it determines that the position of the second target point calculated in step S240 is outside the measurement range, it deletes that position (step S260). Then, the arithmetic processing unit 9 terminates the repeated processing of steps S210 to S260 and proceeds to step S270.

[0132] Through the repeated processing of steps S210 to S260, the arithmetic processing unit 9 calculates the position of each target point for the same number of times that the processing of steps S220 to S260 has been repeated. This allows the computer 7 to prevent an unnecessary increase in the number of target points, and as a result, it can suppress an increase in the number of target measurement points. In other words, the computer 7 can suppress an increase in the time required for radiation interference testing.

[0133] After the processing in step S260 is completed, the calculation processing unit 9 identifies the positions of two or more target measurement points based on the positions of the multiple target points calculated up to that point (step S270). In other words, the calculation processing unit 9 identifies the arrangement of two or more target measurement points through the processing in step S270. Now, the processing in step S270 will be explained.

[0134] For example, the arithmetic processing unit 9 identifies all of the positions of each of the multiple target points calculated to date as the positions of two or more target measurement points. Alternatively, the arithmetic processing unit 9 may identify some of the positions of each of the multiple target points calculated to date as the positions of two or more target measurement points, and may also identify the positions of target points that have not been identified as target measurement points among the positions of the multiple target points calculated to date as the positions of interpolation points. Here, an interpolation point is a virtual point that indicates the position where the electric field strength is estimated by applying a low-pass filter or the like when estimating the distribution of the electric field strength of radiated interference waves. Furthermore, an interpolation point is a virtual point located between two adjacent target measurement points among the multiple target measurement points. When the arithmetic processing unit 9 sets an interpolation point between two or more target measurement points, the method by which the arithmetic processing unit 9 identifies the position of the interpolation point to be located between two or more target measurement points may be a known method or a method to be developed in the future.

[0135] In step S270, the arithmetic processing unit 9 may, after identifying the positions of two or more target measurement points as an arrangement of two or more target measurement points, set interpolation points between the identified two or more target measurement points, or it may, not, set interpolation points between the identified two or more target measurement points.

[0136] After the processing in step S270 is completed, the arithmetic processing unit 9 completes the processing shown in the flowchart in Figure 7, that is, the position determination process in step S140.

[0137] In this way, the computer 7 calculates the position of each of the multiple target points and identifies the positions of two or more target measurement points based on the calculated positions of each of the multiple target points.

[0138] <Method for calculating the upper limit of the measurement interval for radiation interference> The following describes how to calculate the upper limit of the measurement interval for radiated interference waves. Hereinafter, for the sake of simplicity, the method for calculating the upper limit of the measurement interval for radiated interference waves in the circumferential direction of the measurement surface will be described.Note that the method for calculating the upper limit of the measurement interval for radiated interference waves in the circumferential direction of the measurement surface can be applied as a method for calculating the upper limit of the measurement interval for radiated interference waves in the vertical direction of the measurement surface by indicating the vertical position of the measurement surface using the zenith angle from the position on the upper surface of the turntable 4 through which the rotation axis of the turntable 4 passes, instead of the azimuth angle indicating the circumferential position of the measurement surface.

[0139] First, to explain how to calculate the upper limit of the measurement interval for radiated interference waves in the circumferential direction of the measurement surface, we will explain the formulas for the electric field strength and magnetic field strength generated by the minute current wave source Il, and the formulas for the electric field strength and magnetic field strength generated by the minute magnetic current wave source IS. Here, I represents the current, l represents the length of the minute current wave source, and S represents the area of ​​the minute magnetic current wave source. For the sake of explanation, in the following, the measurement interval for radiated interference waves in the circumferential direction of the measurement surface will be simply referred to as the measurement interval for radiated interference waves.

[0140] The equations for the electric field strength and magnetic field strength generated by a minute current wave source Il can be derived from electromagnetism as shown in equation (17) below. Similarly, the equations for the electric field strength and magnetic field strength generated by a minute magnetic current wave source IS can be derived from electromagnetism as shown in equation (18) below. Note that equation (17) represents the electric field strength and magnetic field strength generated by a minute current wave source Il that passes through the origin and flows parallel to the Z-axis direction in a three-dimensional polar coordinate system. Similarly, equation (18) represents the electric field strength and magnetic field strength generated by a minute magnetic current wave source IS that passes through the origin and flows parallel to the Z-axis direction in a three-dimensional polar coordinate system.

[0141]

number

[0142]

number

[0143] Here, in equation (17) above, E represents the electric field strength generated by the minute current wave source Il at an observation point at a distance r from the source Il. Also, in equation (17) above, H represents the magnetic field strength generated by the minute current wave source Il at an observation point at a distance r from the source Il. Also, in equation (18) above, E represents the electric field strength generated by the minute magnetic current wave source IS at an observation point at a distance r from the source IS. Also, in equation (18) above, H represents the magnetic field strength generated by the minute magnetic current wave source IS at an observation point at a distance r from the source IS. Therefore, in equations (17) and (18) above, r represents the distance from the origin to the observation point in the three-dimensional polar coordinate system. Also, in equations (17) and (18) above, φ represents the azimuth angle in the three-dimensional polar coordinate system. Also, in equations (17) and (18) above, θ represents the zenith angle in the three-dimensional polar coordinate system. Furthermore, in equations (17) and (18), j represents the imaginary unit. Also, in equations (17) and (18), k represents the wave number of the minute current wave source Il. Therefore, k represents the wave number of the radiated interference wave generated by the minute current wave source Il. Also, in equation (17), ε represents the permittivity. Also, in equation (18), μ represents the permeability.

[0144] The derivation of equations (17) and (18) above is described in detail in, for example, Chapter 2 (Fundamentals of Antennas) of Group 4 (Mobile / Wireless) - Part 2 (Antennas / Propagation) of the IEICE "Knowledge Forest" (http: / / www.ieice-hbkb.org / ), so further detailed explanation is omitted.

[0145] Here, for simplicity, let's consider the case where the height of the minute current wave source Il and the minute magnetic current wave source IS is the same as the observation point. In this case, the difference between the distance r between the minute current wave source Il and the minute magnetic current wave source IS and the observation point and the wavelength of the radiated interference wave increases as r increases. Then, in equations (17) and (18), the 1 / r term increases as the distance r increases. 2 The term, 1 / r 3The terms in each of these terms become larger. This indicates that as the distance r increases, changes in the electric field strength and magnetic field strength in response to changes in distance r become less likely. In other words, the sensitivity of the electric field strength and magnetic field strength to changes in distance r decreases as the distance r increases. On the other hand, the difference between distance r and the wavelength of the radiated interference wave decreases as the distance r decreases. And in equations (17) and (18), as the distance r decreases, 1 / r 2 The term becomes larger than the term 1 / r. Also, in equations (17) and (18), the shorter the distance r, the larger the 1 / r term becomes. 3 The term is 1 / r 2 The term becomes larger for . This indicates that the shorter the distance r, the more easily changes in electric field and magnetic field strength occur in response to changes in distance r between the minute current wave source Il and the electric field. In other words, the sensitivity of electric field and magnetic field strength to changes in distance r increases as the distance r decreases.

[0146] Thus, in equations (17) and (18), the sensitivity of the electric field strength and magnetic field strength to changes in distance r changes with the length of distance r. However, equation (3) above does not include a parameter that reflects this change in sensitivity of the electric field strength and magnetic field strength to changes in distance r. This is because the Fourier coefficient (a) included in equation (3) p a q +b q b p ), (a p b q -a q b p This is thought to be due to the fact that each of the following is treated as a simple constant. This is because the coefficients of the sine function and cosine function in equations (17) and (18) are the same as the coefficients of the sine function and cosine function in the bottom row of equation (3) (i.e., the Fourier coefficients (a p a q +b q b p ), (a p b q -a q b pThis is because each of the two functions corresponds to the same thing. In other words, treating the coefficients of the sine and cosine functions in the bottom row of equation (3) as constants becomes less justifiable as the distance r decreases. Note that the wavelength of radiated interference becomes shorter as the frequency of the radiated interference increases, and longer as the frequency of the radiated interference decreases. In other words, a higher frequency of radiated interference means that the distance r becomes longer relative to the wavelength of the radiated interference. Also, a lower frequency of radiated interference means that the distance r becomes shorter relative to the wavelength of the radiated interference. Therefore, treating the coefficients of the sine and cosine functions in the bottom row of equation (3) as constants becomes less justifiable as the distance r becomes shorter relative to the wavelength of the radiated interference, that is, as the frequency of the radiated interference decreases. So, let's assume that these coefficients are periodic functions with respect to the azimuth angle φ from the electromagnetic wave source (i.e., the small current wave source Il and the small magnetic current wave source IS) to the observation point. With this, these coefficients can be treated as a Fourier series. The following equation (19) is obtained by transforming equation (3) as a result of such treatment.

[0147]

number

[0148] In equation (19) above, A nl , A ml B nl B ml Each of these is a Fourier coefficient. Also, k in equation (19) nφ , k mφ Each of these is the spatial wavenumber for the azimuth angle φ in a three-dimensional polar coordinate system, and k φ =2πf φ That is the case. φis the spatial frequency for the azimuth angle φ. Looking at equation (19), we can see that even if we treat the coefficients of the sine and cosine functions in the bottom row of equation (3) as Fourier series, it is possible to express the square of the electric field strength as a sum of sine waves. Comparing equation (19) with equation (3), we can see that φ, which did not appear in equation (3), is present. nl , φ ml It can be seen that terms proportional to appear within the phase of the sine function in equation (19) and within the phase of the cosine function in equation (19).

[0149] Equation (19) is φ nl against k rn / k rφ If k is sufficiently large, it reduces to equation (3). This is because k rn / k rφ However, this corresponds to the ratio of the wavelength of the radiated interference wave to the measurement interval of the radiated interference wave, φ nl against k rn / k rφ This is because a larger value means that the frequency of the radiated interference wave increases, that is, the distance r becomes longer relative to the wavelength of the radiated interference wave. And this is because, with respect to the square of the electric field strength shown in equation (19), k n , k m This means that a bandwidth limitation is applied to the spatial frequency based on this. The arrangement shown in the flowchart in Figure 6 is generated as an arrangement that reflects this bandwidth limitation, based on the sampling theorem mentioned above. As a result, the radiation interference measuring device 100 can, in this case, perform radiation interference testing using the arrangement shown in the arrangement information generated by the flowchart in Figure 6, thereby suppressing a decrease in the estimation accuracy of the maximum electric field strength location in radiation interference testing while suppressing an increase in the time required for radiation interference testing. In other words, in this case, the measurement interval for radiation interference in the arrangement shown in the arrangement information generated by this process is a measurement interval that can guarantee high accuracy as an estimation accuracy of the maximum electric field strength location.

[0150] On the other hand, equation (19) is φnl against k rn / k rφ If φ is sufficiently small, nl , φ ml The term proportional to k can no longer be approximately ignored, and the result no longer reduces to equation (3). This is because k rn / k rφ However, this corresponds to the ratio of the wavelength of the radiated interference wave to the measurement interval of the radiated interference wave, φ nl against k rn / k rφ This is because a decrease in k means that the frequency of the radiated interference wave decreases, that is, the distance r becomes shorter relative to the wavelength of the radiated interference wave. As a result, the square of the electric field strength shown in equation (19) includes k nφ , k mφ A bandwidth limitation is applied to the spatial frequency based on this. That is, the radiated interference measuring device 100 operates under such bandwidth limitation. nφ , k mφ If we can obtain the maximum possible value, we can generate a configuration of two or more measurement points that reflects this bandwidth limitation. This is because the reciprocal of this maximum value corresponds to the maximum possible interval for measuring radiated interference waves in the azimuthal direction on the measurement surface, i.e., the upper limit of the measurement interval for radiated interference waves. In other words, the reciprocal of this maximum value can be converted to the maximum possible interval for measuring radiated interference waves in the azimuthal direction (i.e., the circumferential direction on the measurement surface), i.e., the upper limit of the measurement interval for radiated interference waves. In this conversion, finding this maximum value is equivalent to finding the maximum possible value of the spatial frequency for an azimuthal angle φ under the bandwidth limitation. For the sake of explanation, below we will refer to the spatial frequency for an azimuthal angle φ simply as spatial frequency, and the maximum possible value of the spatial frequency under the bandwidth limitation as the maximum spatial frequency.

[0151] The maximum spatial frequency can also be calculated using the sampling theorem. However, such calculations are extremely complex and can be difficult for anyone but an expert to handle. Therefore, this specification omits the explanation of calculations using the sampling theorem and instead describes a simpler method for calculating the maximum spatial frequency as an example. This method estimates the maximum spatial frequency using statistical analysis with the Monte Carlo method instead of the sampling theorem. In other words, this method estimates the upper limit of the measurement interval for radiated interference waves using statistical analysis with the Monte Carlo method instead of the sampling theorem. For the sake of explanation, this method will be referred to as the target estimation method below.

[0152] The target estimation method is φ nl k for rn / k rφ The maximum spatial frequency can be estimated regardless of the magnitude of . Therefore, whether the maximum spatial frequency estimated by the target estimation method is valid or not depends on φ nl against k rn / k rφ When the value is sufficiently small, this can be determined by comparing the measurement interval of radiated interference waves corresponding to the maximum spatial frequency estimated by the target estimation method with the maximum value of the measurement interval of radiated interference waves in that case, calculated by the flowchart shown in Figure 6.

[0153] In the target estimation method, first, the measured electric field strength distribution created by the two electromagnetic wave sources is estimated. This is because equation (19) above is calculated based on the two electromagnetic wave sources. Here, in the estimation of the measured electric field strength distribution in the target estimation method, the positions of the two electromagnetic wave sources are given randomly within the aforementioned electromagnetic wave source region. Then, in the target estimation method, the random assignment of the positions of the two electromagnetic wave sources is repeated a predetermined number of times, and each time the positions of the two electromagnetic wave sources are randomly assigned, the measured electric field strength distribution is estimated based on the given positions of the two electromagnetic wave sources. Furthermore, in the target estimation method, this predetermined number of estimations of the measured electric field strength distribution is repeated each time the frequency of the radiated interference waves generated from the two electromagnetic wave sources is changed. In the target estimation method, the maximum spatial frequency is estimated by statistical analysis based on the measured electric field strength distribution estimated for a predetermined number of times for each frequency of the radiated interference waves. In other words, the target estimation method estimates the upper limit of the measurement interval for radiated interference waves by performing a statistical analysis based on a predetermined number of measurement target electric field strength distributions estimated for each frequency of radiated interference waves.

[0154] More specifically, the target estimation method estimates the maximum spatial frequency, as described below. First, in the target estimation method, the measurement target electric field strength distribution created by two electromagnetic wave sources can be estimated using at least one of the above equations (17) and (18). However, in equation (17), the maximum order of distance r is 3. Also, in equation (17), 1 / r 3 The term is included only in the formula for electric field strength. Also, in equation (18), the maximum order of distance r is 3. Also, in equation (18), 1 / r 3The term is included only in the equation for magnetic field strength. Therefore, the estimation of the target electric field strength distribution created by two electromagnetic wave sources can be performed with sufficient accuracy by either estimating the electric field strength using equation (17) or estimating the magnetic field strength using equation (18). Accordingly, below, as an example, we will explain the case in the target estimation method where the estimation of the target electric field strength distribution created by two electromagnetic wave sources is performed by estimating the electric field strength using equation (17). Note that a typical electromagnetic wave source is a sum of minute electromagnetic wave sources. Therefore, it is considered justifiable to use minute electromagnetic wave sources as a model for a typical electromagnetic wave source.

[0155] Equation (17) includes the position, orientation, amplitude, phase, and wavenumber of the electromagnetic wave source as parameters indicating a minute electromagnetic wave source. Therefore, in the estimation of the target electric field strength distribution created by two electromagnetic wave sources in the target estimation method, when using the Monte Carlo method, the orientation, amplitude, and phase of the two electromagnetic wave sources are randomly assigned along with the positions of the two electromagnetic wave sources. As mentioned above, in the target estimation method, the wavenumber of the electromagnetic wave source, i.e., the frequency of the radiated interference wave, is given separately from the position, orientation, amplitude, and phase of the two electromagnetic wave sources. In other words, in the target estimation method, for each change in the wavenumber of the electromagnetic wave source, the estimation of the target electric field strength distribution is performed a predetermined number of times using the Monte Carlo method, where the position, orientation, amplitude, and phase of the two electromagnetic wave sources are randomly assigned. The predetermined number of times can be any number of times, as long as it is two or more. However, the more predetermined times there are, the higher the estimation accuracy of the maximum spatial frequency in the target estimation method.

[0156] In the following, as an example, we will describe the case where the random numbers used to randomly change the position, direction, amplitude, and phase of the two electromagnetic wave sources are uniformly distributed random numbers. Furthermore, the relative values ​​of the two electromagnetic wave sources are important for their amplitudes. For this reason, setting an upper limit for the random numbers is not important. Therefore, in the following, we will describe the case where the upper limit is 1 as an example. Also, the direction and phase of the electromagnetic wave sources are periodic. For this reason, the direction and phase of the electromagnetic wave sources are set with a limit of one rotation each. Furthermore, the target estimation method in this example estimates the maximum spatial frequency for a given azimuth angle φ. For this reason, in the target estimation method, the measurement surface may be treated as the circumference surrounding the two electromagnetic wave sources. This allows the computer 7 to reduce the computational load. Therefore, in the following, as an example, we will describe the case where the measurement surface is treated as the circumference surrounding the two electromagnetic wave sources. And, for the sake of explanation, in the following, a circle with such a circumference will be referred to as the measurement circle. The circumference of the measurement circle is, for example, the circumference of the circle formed by cutting the measurement surface along a horizontal plane.

[0157] Figure 8 shows an example of the positional relationship between two electromagnetic wave sources located within the electromagnetic wave source region and an observation point positioned on the circumference of the measurement circle. Figure 8 also shows an example of the electromagnetic wave source region as viewed in the direction of gravity. The hatched region R1 in Figure 8 represents an example of the electromagnetic wave source region. The circumference R2 shown in Figure 8 represents an example of the circumference of the measurement circle. The position S1 shown in Figure 8 represents an example of the position of one of the two electromagnetic wave sources. The position S2 shown in Figure 8 represents an example of the position of the other of the two electromagnetic wave sources. In other words, in the Monte Carlo method using equation (17), the position, orientation, amplitude, and phase of the two electromagnetic wave sources within region R1 are randomly changed for each estimation of the electric field strength. nl This indicates the distance from the electromagnetic wave source located at position S1 to the observation point. Also, as shown in Figure 8, r ml This indicates the distance from the electromagnetic wave source located at position S1 to the observation point.

[0158] In the target estimation method, multiple target electric field strength distributions are estimated using the Monte Carlo method with the parameters provided as described above. The electric field strength distributions estimated in this way can be transformed into spectra with respect to spatial frequency using a Fourier transform. For the sake of explanation, such spectra will be referred to as spatial frequency spectra below. Figure 9 shows an example of spatial frequency spectra corresponding to each of the multiple target electric field strength distributions estimated by the target estimation method when the frequency of the radiated interference wave coincides with a certain frequency. The vertical axis of the graph in Figure 9 shows the magnitude of the electric field strength for the DC (Direct Current) component in dB. The horizontal axis of the graph shows the spatial frequency normalized by 360° (i.e., 2π [rad]). The multiple curves plotted on the graph show examples of spatial frequency spectra corresponding to each of the multiple target electric field strength distributions estimated by the target estimation method in this case.

[0159] In the target estimation method, as shown in Figure 9, spatial frequencies are identified in all spatial frequency spectra where the magnitude of the electric field intensity matches a predetermined threshold. In the example shown in Figure 9, the predetermined threshold is -40 dB. Therefore, in this example, the spatial frequencies identified in this way are 12 spatial frequencies, from spatial frequency X1 to spatial frequency X12. That is, in the example shown in Figure 9, the predetermined number of times is 12. The predetermined threshold is determined as the maximum value of the magnitude of the electric field intensity of the radiated interference wave that is negligible in the radiated interference wave test. Therefore, there is arbitrariness in how the predetermined threshold is determined. That is, the predetermined threshold may be less than -40 dB or greater than -40 dB. Furthermore, the predetermined threshold may be determined through prior tests or other means to improve the accuracy of estimating the location of the maximum electric field intensity.

[0160] Subsequently, the estimation method calculates the center value μ and variance σ of the 12 spatial frequencies identified in this way. The center value μ may be the median of these 12 spatial frequencies, or it may be the average value of these 12 spatial frequencies. Then, the estimation method estimates the spatial frequency shifted by +3σ from the calculated center value μ as the maximum spatial frequency. This is to achieve a confidence interval of 99.9%.

[0161] The target estimation method estimates the maximum spatial frequency for each wavenumber of the radiated interference wave. Therefore, the target estimation method can generate a graph like the one shown in Figure 10. Figure 10 shows an example of the relationship between the measurement interval of the radiated interference wave and the frequency of the radiated interference wave, corresponding to the maximum spatial frequency for each frequency of the radiated interference wave. The vertical axis of the graph in Figure 10 represents the measurement interval of the radiated interference wave obtained according to the maximum spatial frequency estimated by the target estimation method, which is obtained by multiplying the reciprocal of the maximum spatial frequency estimated by the target estimation method by a safety factor of 4 / 5. Therefore, the value on the vertical axis approaches 0.1 as the maximum spatial frequency increases (i.e., the measurement interval of the radiated interference wave decreases), and approaches 1000 as the maximum spatial frequency decreases (i.e., the measurement interval of the radiated interference wave increases). The horizontal axis of the graph represents the value obtained by dividing the measurement distance, which is the distance from the rotation axis of the turntable 4 to the observation point, by the wavelength of the radiated interference wave, which is determined according to the frequency of the radiated interference wave. Therefore, the value on the horizontal axis approaches 0.001 as the frequency of the radiated interference wave decreases, and approaches 100 as the frequency of the radiated interference wave increases. For the sake of explanation, in the following, the value on the horizontal axis will be referred to as the frequency equivalent value. Note that the above safety factor may be less than 4 / 5 or greater than 4 / 5 instead of 4 / 5.

[0162] Furthermore, the curve F1 plotted in the graph shown in Figure 10 shows an example of the change in the maximum measurement interval of radiated interference, calculated by the flowchart shown in Figure 6, in response to a change in the frequency equivalent value. Note that the upper limit of curve F1 (i.e., the upper limit of the measurement interval of radiated interference) is 360° (indicated by 360 [deg] in Figure 10) because at least one measurement point must be set. Also, the curve F2 plotted in the same graph shows an example of the change in the maximum spatial frequency estimated by the target estimation method in response to a change in the frequency equivalent value. As shown in Figure 10, curve F2 asymptotically approaches curve F1 in the region where the frequency equivalent value is high (i.e., the region where the frequency of radiated interference is high). Here, the region where the frequency equivalent value is high is φ nl against k rn / k rφ This can be interpreted as a sufficiently small region. In this region, the asymptotic approach of curve F2 to curve F1 means that, when the frequency of radiated interference is high, the measurement interval of radiated interference corresponding to the maximum spatial frequency estimated by the target estimation method approaches the maximum value of the measurement interval of radiated interference in that case calculated by the flowchart shown in Figure 6. Thus, the estimation of the maximum spatial frequency by the target estimation method can be considered valid. However, in the region of low frequency equivalent values ​​(i.e., the region of low radiated interference frequencies), curve F2 deviates significantly from curve F1. This means that in the region of low frequency equivalent values, determining the measurement interval of radiated interference based on the maximum spatial frequency estimated by the target estimation method yields higher accuracy in estimating the location of the maximum electric field strength than the flowchart shown in Figure 6. In this graph, curve F1 is located below curve F2 overall. Therefore, the radiation interference measuring device 100 can accurately estimate the electric field strength distribution to be measured while suppressing the increase in the time required for radiation interference testing for radiation interference with frequencies included in a wider frequency band, by determining the measurement interval of radiation interference based on the frequency of radiation interference and curve F2.

[0163] However, determining the measurement interval for radiated interference based on the frequency of the radiated interference and curve F2 each time a radiated interference test is performed could increase the complexity of the process. This is because the shape of curve F2 is not a simple shape like a combination of two straight lines. Therefore, as will be explained below, the radiated interference measuring device 100 can indicate the upper limit of the measurement interval for radiated interference in the region of low frequency equivalent values ​​based on curve F2, and identify a curve F3 that coincides with curve F1 in the region of high frequency equivalent values. In other words, curve F3 is a curve that asymptotically approaches curve F2 in the region of high frequency equivalent values ​​and asymptotically approaches curve F1 in the region of low frequency equivalent values. An example of such a curve F3 is plotted in Figure 10.

[0164] For example, to identify curve F3, the radiation interference measuring device 100 identifies a region where curve F1 remains approximately unchanged and calculates the average value of the maximum spatial frequency on curve F1 within the identified region. When using curve F3 to determine the upper limit of the measurement interval for radiation interference, the average value of this value becomes the upper limit of the measurement interval for radiation interference. After calculating the average value of this value, the radiation interference measuring device 100 identifies a straight line horizontal to the horizontal axis passing through the calculated average value and identifies the intersection point between this straight line and curve F1. Then, the radiation interference measuring device 100 identifies the straight line connecting the portion of curve F2 that is higher frequency than the identified intersection point to this straight line as curve F3. Note that the method for identifying curve F3 may be other than this. Also, curve F3 may be manually determined by the user of the radiation interference measuring device 100, for example, based on a graph like the one shown in Figure 10.

[0165] By using the curve F3 identified in this way, the radiation interference measurement device 100 can select the upper limit of the radiation interference measurement interval shown by curve F3 as the measurement interval for radiation interference in the region of low frequency equivalent values, and select the measurement interval for radiation interference shown by curve F3, i.e., the measurement interval for radiation interference shown by curve F1, in the region of high frequency equivalent values. As a result, the radiation interference measurement device 100 can accurately estimate the target electric field strength distribution while suppressing an increase in the time required for radiation interference testing for radiation interference with frequencies included in a wider frequency band.

[0166] The curve F2 plotted in the graph shown in Figure 10 changes depending on the ratio of the measurement distance (horizontal distance from the rotation axis of the turntable 4 to the observation point) to the radius of the electromagnetic wave source region. For the sake of explanation, this ratio will be referred to as the analysis target ratio below. The curve F2 shown in Figure 10 is the curve obtained as a result of estimating the measured target electric field strength distribution using the target estimation method when the analysis target ratio is 2. Figure 11 shows an example of how the spatial frequency spectrum value changes in response to the change in the analysis target ratio when the value on the horizontal axis of the graph shown in Figure 10 is 0.001. The vertical axis of the graph shown in Figure 11 is the same as the vertical axis of the graph shown in Figure 10 and indicates the measurement interval of radiated interference waves. The horizontal axis of this graph indicates the analysis target ratio.

[0167] Here, the curve F4 plotted on the graph shown in Figure 11 shows an example of how the measurement interval of radiated interference, determined according to the maximum spatial frequency estimated by the target estimation method when the frequency equivalent value is 0.001, changes in response to changes in the analysis target ratio. Curve F4 shows that the measurement interval of radiated interference changes approximately linearly up to an analysis target ratio of 16. Furthermore, curve F4 shows that the measurement interval of radiated interference becomes approximately constant at 16 and above. Here, the measurement intervals of radiated interference indicated by points on the curve located below curve F4 as a whole in this graph are all measurement intervals that allow for accurate estimation of the maximum electric field strength location when the frequency equivalent value is 0.001. In addition, a frequency equivalent value of 0.001 is close to the lowest frequency of radiated interference that can be measured in the current stage of radiated interference testing. Therefore, by plotting a curve that asymptotically approaches curve F4 and is located below curve F4 overall on the graph, it is possible to generate correspondence information that associates the upper limit of the measurement interval for radiation interference with the analysis target ratio, while suppressing an increase in the time required for radiation interference testing and accurately estimating the target electric field strength distribution. The curve F5 shown in Figure 11 is an example of a curve that asymptotically approaches curve F4 and is located below curve F4 overall on the graph. By using such correspondence information, the radiation interference measuring device 100 can easily identify the upper limit of the measurement interval for radiation interference according to the analysis target ratio received. This is a simpler method than the method using curve F3 described above and is useful in radiation interference testing. Note that the radiation interference measuring device 100 may plot curve F5 on the graph, for example, according to an operation received from the user, or by various processing based on curve F4. The various processing steps may include, for example, plotting a curve that changes linearly within the range of analysis target ratio 1 to 16, and then shows a constant value, as curve F5. In this case, the slope of the linearly changing portion of curve F5 is, for example, the value obtained by multiplying the slope of curve F4 within the range of analysis target ratio 1 to 16 by a predetermined ratio, but it may be a value determined by another method instead.The predetermined percentage is, for example, 90%, but it may be a percentage smaller than 90%, or a percentage larger than 90%.

[0168] In the target estimation method described above, the Monte Carlo method was used. However, instead, for example, multiple different test specimens may be prepared, and the measurement target electric field strength distribution may be measured for each of the prepared specimens to calculate multiple spatial frequency spectra. Even in this case, the radiation interference measurement device 100 can identify curves such as curve F3 and curve F5 using the same method as described above, that is, using statistical analysis. As a result, the radiation interference measurement device 100 can calculate (identify) the upper limit of the measurement interval for radiation interference. In other words, even in this case, the radiation interference measurement device 100 can accurately estimate the measurement target electric field strength distribution while suppressing an increase in the time required for radiation interference testing for radiation interference with frequencies included in a wider frequency band.

[0169] <Process for calculating the upper limit of the measurement interval for radiation interference> The following describes the process by which the radiation interference measuring device 100 calculates the upper limit of the measurement interval for radiation interference, with reference to Figure 12. Figure 12 is a diagram showing an example of the process flow for the radiation interference measuring device 100 to calculate the upper limit of the measurement interval for radiation interference. As an example, the following describes a case in which the radiation interference measuring device 100 receives an operation to start the process of calculating the upper limit of the measurement interval for radiation interference at a timing prior to the processing of step S110 shown in Figure 12. Furthermore, as an example, the following describes a case in which, at that timing, analysis target ratio information indicating each of a predetermined number of different analysis target ratios is stored in the recording medium 15 of the storage device 13. The number of different analysis target ratios are, for example, individual integers included in the closed interval from 1 to 32, but other values ​​may be used instead. Furthermore, as an example, the following describes a case in which, at that timing, frequency information indicating each of a number of different frequencies is stored in the recording medium 15 of the storage device 13. Furthermore, as an example, the case in which the aforementioned measurement condition information is stored in the recording medium 15 of the storage device 13 at that timing will be described below.

[0170] The arithmetic processing unit 9 reads the analysis target ratio information previously stored in the recording medium 15 of the storage device 13 from the recording medium 15, and for each of the multiple analysis target ratios indicated by the read analysis target ratio information, it repeatedly performs the processing in steps S320 to S370 (step S310).

[0171] After the analysis target ratio is selected in step S310, the calculation processing unit 9 reads the measurement condition information previously stored in the recording medium 15 of the storage device 13 from the recording medium 15 (step S320).

[0172] Next, the arithmetic processing unit 9 reads frequency information previously stored in the recording medium 15 of the storage device 13 from the recording medium 15. Then, the arithmetic processing unit 9 identifies each of the multiple frequencies indicated by the read frequency information as a radiation interference wave frequency, and repeats the processing in steps S340 to S350 for each identified radiation interference wave frequency (step S330).

[0173] In step S330, after the frequency of the radiation interference wave is selected, the arithmetic processing unit 9 estimates the target electric field strength distribution a predetermined number of times using the measurement condition information read in step S320 and the Monte Carlo method in the target estimation method, thereby estimating that number of target electric field strength distributions (step S340). Subsequently, in step S340, the arithmetic processing unit 9 performs a Fourier transform on each of the estimated target electric field strength distributions and calculates that number of spatial frequency spectra. In addition, if the arithmetic processing unit 9 needs to identify, for example, the size of the electromagnetic wave source region, it will perform calculations and identification based on the measurement condition information.

[0174] Next, the arithmetic processing unit 9, based on a predetermined number of spatial frequency spectra calculated in step S340, identifies the maximum spatial frequency corresponding to the frequency of the radiation interference wave in step S330 using the target estimation method (step S350). After identifying the maximum spatial frequency in step S350, the arithmetic processing unit 9 transitions to step S330 and selects the next frequency. After transitioning to step S330, if there are no unselected frequencies in step S330, the arithmetic processing unit 9 terminates the repetition of steps S330 to S350 and transitions to step S360.

[0175] After completing the iterative processing from steps S330 to S350, the calculation processing unit 9 calculates an upper limit for the measurement interval of radiation interference waves based on the maximum spatial frequency identified for each of the multiple frequencies through the iterative processing using the target estimation method (step S360).

[0176] Next, the arithmetic processing unit 9 stores the upper limit information, which indicates the upper limit of the measurement interval for radiation interference calculated in step S360, in the recording medium 15 of the storage device 13, corresponding to the analysis target ratio selected in step S310 (step S370). After storing the upper limit information in step S370, the arithmetic processing unit 9 transitions to step S310 and selects the next analysis target ratio. After transitioning to step S310, if there are no analysis target ratios that have not been selected in step S310, the arithmetic processing unit 9 terminates the repetition of steps S310 to S370 and transitions to step S380.

[0177] After completing the iterative processing from steps S310 to S370, the arithmetic processing unit 9 generates the aforementioned correspondence information based on the multiple upper limit values ​​stored in the recording medium 15 of the storage device 13 during the iterative processing (step S380).

[0178] Next, the arithmetic processing unit 9 stores the correspondence information generated in step S380 into the recording medium 15 of the storage device 13 (step S390), and terminates the processing of the flowchart shown in Figure 12.

[0179] As described above, the radiation interference measurement device 100 calculates an upper limit for the measurement interval of radiation interference by the antenna 2 based on the target estimation method, the positions of multiple electromagnetic wave sources corresponding to the test specimen emitting radiation interference, and the relative positional relationship between the antenna 2 that measures radiation interference and the test specimen. This allows the radiation interference measurement device 100 to accurately estimate the electric field strength distribution of the measurement target while suppressing an increase in the time required for radiation interference testing for radiation interference with frequencies included in a wider frequency band. As a result, the radiation interference measurement device 100 can accurately estimate the location of the maximum electric field strength while suppressing an increase in the time required for radiation interference testing for radiation interference with frequencies included in a wider frequency band.

[0180] <Process for estimating the target electric field strength distribution using the upper limit of the measurement interval for radiation interference> The following describes the process by which the radiation interference measuring device 100 estimates the target electric field strength distribution using the upper limit of the measurement interval for radiation interference, with reference to Figure 13. Figure 13 is a diagram showing an example of the process flow for which the radiation interference measuring device 100 estimates the target electric field strength distribution using the upper limit of the measurement interval for radiation interference. As an example, the following describes the case where the radiation interference measuring device 100 receives an operation to start the process of estimating the target electric field strength distribution using the upper limit of the measurement interval for radiation interference at a timing prior to the processing of step S410 shown in Figure 13. Furthermore, as an example, the following describes the case where, at that timing, the processing of the flowchart shown in Figure 12 has been performed and the corresponding information is stored in the recording medium 15 of the storage device 13. Furthermore, as an example, the following describes the case where, at that timing, the measurement condition information is stored in the recording medium 15 of the storage device 13.

[0181] The arithmetic processing unit 9 reads the measurement condition information that has been pre-stored in the recording medium 15 of the storage device 13 from the recording medium 15 (step S410).

[0182] Next, the arithmetic processing unit 9 reads the corresponding information previously stored in the recording medium 15 of the storage device 13 from the recording medium 15 (step S420).

[0183] Next, the arithmetic processing unit 9 calculates the analysis target ratio based on the measurement condition information read in step S410. Then, based on the calculated analysis target ratio and the corresponding information read in step S420, the arithmetic processing unit 9 identifies the upper limit of the measurement interval for the radiated interference waves associated with the analysis target ratio (step S430).

[0184] Next, the arithmetic processing unit 9 calculates the arrangement of two or more measurement points according to the flowchart shown in Figure 6 (step S440). Note that since the arithmetic processing unit 9 has already read the measurement condition information in step S410, the processing in step S440 may omit the processing in step S120 in the flowchart.

[0185] Next, the arithmetic processing unit 9 determines whether the maximum value of the measurement interval for radiated interference waves in the arrangement calculated in step S440 exceeds the upper limit value identified in step S430 (step S450).

[0186] If the arithmetic processing unit 9 determines that the maximum measurement interval for radiated interference waves in the arrangement calculated in step S440 is less than or equal to the upper limit specified in step S430 (step S450-NO), it decides that arrangement to be the arrangement of two or more measurement points to be set on the measurement surface. Then, the arithmetic processing unit 9 controls the controller 6 and receiver 5 using the decided arrangement of two or more measurement points and measures the target electric field strength at the measurement positions indicated by each of the two or more measurement points indicated by the arrangement (i.e., actual measurement of the target electric field strength) (step S470). In step S470, the arithmetic processing unit 9 may be configured to calculate the target electric field strength at each measurement position by simulation based on electromagnetism.

[0187] Next, the arithmetic processing unit 9 obtains the distribution of the target electric field strength based on all the target electric field strengths measured in step S470 (step S480). In other words, in step S480, the arithmetic processing unit 9 estimates the distribution of the target electric field strength based on all the target electric field strengths measured in step S470.

[0188] Next, the arithmetic processing unit 9 interpolates the target electric field strength distribution acquired in step S480 (step S490). For example, in step S490, the arithmetic processing unit 9 interpolates the target electric field strength distribution using a low-pass filter. Also in step S490, the arithmetic processing unit 9 uses, for example, the reciprocal of the measurement interval of the radiated interference wave as the cutoff frequency of the low-pass filter. Note that the arithmetic processing unit 9 may be configured to interpolate the target electric field strength distribution by a method other than using a low-pass filter. Alternatively, the arithmetic processing unit 9 may omit the processing in step S490 and not interpolate the target electric field strength distribution.

[0189] Next, the arithmetic processing unit 9 generates measurement target electric field strength distribution information showing the interpolated measurement target electric field strength distribution in step S490, stores the generated measurement target electric field strength distribution information in the recording medium 15 of the storage device 13 (step S500), and terminates the processing of the flowchart shown in Figure 13.

[0190] On the other hand, if the arithmetic processing unit 9 determines that the maximum measurement interval for radiated interference in the arrangement calculated in step S440 exceeds the upper limit specified in step S430 (step S450-YES), it proceeds to step S470, adopts the upper limit as the measurement interval for radiated interference, and determines an arrangement of two or more measurement points corresponding to the adopted measurement interval for radiated interference as the arrangement of two or more measurement points to be set on the measurement surface. Then, the arithmetic processing unit 9 controls the controller 6 and receiver 5 using the determined arrangement of two or more measurement points and measures the target electric field strength at the measurement positions indicated by each of the two or more measurement points indicated by the arrangement (i.e., actual measurement of the target electric field strength). Note that, as described above, the arithmetic processing unit 9 may also be configured to calculate the target electric field strength at each measurement position by simulation based on electromagnetism in step S470.

[0191] As described above, if the maximum value of the measurement interval for radiated interference calculated in step S440 exceeds the upper limit value specified in step S430, the radiated interference measuring device 100 selects the upper limit value as the measurement interval to be used for the radiated interference test. If the maximum value of the measurement interval calculated in step S440 is less than or equal to the calculated upper limit value, the device selects the measurement interval calculated in step S440 as the measurement interval to be used for the radiated interference test. In other words, the radiated interference measuring device 100 can automatically switch the measurement interval for radiated interference without accepting any input from the user. As a result, the radiated interference measuring device 100 can accurately estimate the distribution of electromagnetic field strength of radiated interference on a virtual surface surrounding the test specimen, while suppressing an increase in the time required for radiated interference tests for radiated interference with frequencies included in a wider frequency band, and can also suppress an increase in the amount of work performed by the user in the radiated interference test.

[0192] Figure 14 is a diagram for comparing the measured target electric field strength distribution estimated by the flowchart shown in Figure 13 based on certain measurement conditions with the actual measured target electric field strength distribution estimated by simulations based on the same measurement conditions and electromagnetism. The frequency of the radiated interference wave under the measurement conditions is 100 kHz, which is an example of a frequency included in the low frequency range of the aforementioned radiated interference wave. The vertical axis of the graph shown in Figure 14 represents the electric field strength. The horizontal axis of the graph shows the circumferential position of the cylinder on the cylindrical measurement surface, expressed by the azimuth angle around the rotation axis of the turntable 4. Curve F6 plotted on the graph shows an example of the actual measured target electric field strength distribution estimated by simulations based on electromagnetism. The multiple points plotted on the graph represent multiple measured target electric field strengths measured by the flowchart shown in Figure 13 based on certain measurement conditions. As shown in Figure 13, these multiple points are located on curve F6. The measured target electric field strength distribution estimated by the said process based on these multiple measured target electric field strengths is shown by curve F7 in the graph. As shown in Figure 13, the measured electric field strength distribution shown by curve F6 and the measured electric field strength distribution shown by curve F7 largely overlap. More specifically, the position of the maximum electric field strength in the measured electric field strength distribution shown by curve F6 and the position of the maximum electric field strength in the measured electric field strength distribution shown by curve F7 coincide or nearly coincide. Therefore, the radiated interference wave measuring device 100 can accurately estimate the measured electric field strength distribution even in the low frequency region of radiated interference waves by estimating the measured electric field strength distribution through the processing of the flowchart shown in Figure 13. In other words, the radiated interference wave measuring device 100 can accurately estimate the measured electric field strength distribution while suppressing the increase in the time required for radiated interference wave testing for radiated interference waves with frequencies included in a wider frequency band.

[0193] <Other variations> When the computer 7 identifies the arrangement of two or more measurement points in the aforementioned azimuth direction rather than the vertical direction, it uses the following formula (20) in place of the above formula (15).

[0194] [Math.]]

[0195] Here, R in the above formula (20) max represents the radius of the upper and lower surfaces included in the specimen information as information indicating the size of the specimen 1. The upper and lower surfaces refer to the upper and lower surfaces of the smallest cylindrical region among virtual regions encompassing the entire specimen 1 placed on the turntable 4. This allows the computer 7 to specify the arrangement of two or more measurement points also in the azimuth direction, and as a result, it is possible to accurately estimate the electric field intensity distribution to be measured while suppressing an increase in the time required for the radiated emission test. Note that the arrangement is an arrangement in the azimuth direction around a rotation axis predetermined to be parallel to the direction of gravity (that is, the rotation axis of the turntable 4).

[0196] As described above, the radiated emission measurement apparatus 100 according to the embodiment calculates the upper limit value of the measurement interval of radiated emission by the antenna 2 based on the positions of a plurality of electromagnetic wave sources corresponding to a specimen that radiates radiated emission and the relative positional relationship between the antenna 2 that measures radiated emission and the specimen. Accordingly, the radiated emission measurement apparatus 100 can accurately estimate the electric field intensity distribution to be measured while suppressing an increase in the time required for a radiated emission test for radiated emission having frequencies included in a wider frequency band. Note that the matters described above may be combined in any manner.

[0197] <Supplementary Note> [1] In a computer, A first calculation step involves calculating an upper limit for the measurement interval of the radiated interference waves by the antenna, based on the positions of multiple electromagnetic wave sources corresponding to the test specimen radiating the radiated interference waves and the relative positional relationship between the antenna that measures the radiated interference waves and the test specimen. A program to execute. [2] The measurement interval refers to the distance between adjacent measurement positions among the multiple measurement positions where the radiated interference waves are measured by the antenna. The program described in [1]. [3] A second calculation step is performed to calculate the measurement interval based on the positions of the plurality of electromagnetic wave sources, the positional relationship, the wavelength of the radiated interference wave, and the sampling theorem. The program described in [1] or [2]. [4] If the maximum value of the measurement interval calculated in the second calculation step exceeds the upper limit value calculated in the first calculation step, the upper limit value is selected as the measurement interval to be used in the radiation interference test for measuring the radiation interference waves. If the maximum value of the measurement interval calculated in the second calculation step is less than or equal to the upper limit value calculated in the first calculation step, a selection step is executed to select the measurement interval calculated in the second calculation step as the measurement interval to be used in the radiation interference test. The program described in [3]. [5] The first calculation step involves calculating the upper limit based on statistical analysis. A program described in any one of the items [1] through [4]. [6] A third calculation step is performed to calculate the distribution of at least one of the distributions of the electric field strength of the radiated interference wave and the magnetic field strength of the radiated interference wave, based on the upper limit value calculated in the first calculation step. A program described in any one of the items [1] through [5]. [7] An acquisition step of obtaining at least one of the aforementioned distributions by simulation or actual measurement, An interpolation step of interpolating at least one of the distributions using a low-pass filter, The program described in [6] that causes the execution of the following. [8] A first calculation step in which, based on the positions of multiple electromagnetic wave sources corresponding to the test specimen emitting the radiated interference waves, and the relative positional relationship between the antenna that measures the radiated interference waves and the test specimen, the upper limit of the measurement interval for the radiated interference waves by the antenna is calculated. An information processing method having [9] The measurement interval refers to the distance between adjacent measurement positions among the multiple measurement positions where the radiated interference waves are measured by the antenna. The information processing method described in [8].

[10] The system includes a second calculation step for calculating the measurement interval based on the positions of the plurality of electromagnetic wave sources, the positional relationship, the wavelength of the radiated interference wave, and the sampling theorem. The information processing method described in [8] or [9].

[11] The system has a selection step in which, if the maximum value of the measurement interval calculated in the second calculation step exceeds the upper limit value calculated in the first calculation step, the system selects the upper limit value as the measurement interval to be used for the radiation interference test to measure the radiation interference waves, and if the maximum value of the measurement interval calculated in the second calculation step is less than or equal to the upper limit value calculated in the first calculation step, the system selects the measurement interval calculated in the second calculation step as the measurement interval to be used for the radiation interference test. The information processing method described in

[10] .

[12] The first calculation step involves calculating the upper limit based on statistical analysis. The information processing method described in any one of items [8] to

[11] .

[13] A third calculation step is to calculate the distribution of at least one of the distributions of the electric field strength of the radiated interference wave and the magnetic field strength of the radiated interference wave, based on the upper limit value calculated in the first calculation step. The information processing method described in any one of items [8] to

[12] .

[14] An acquisition step of obtaining at least one of the aforementioned distributions by simulation or actual measurement, An interpolation step of interpolating at least one of the distributions using a low-pass filter, The information processing method described in

[13] , having the following:

[15] Based on the positions of multiple electromagnetic wave sources corresponding to the specimen emitting the radiated interference waves, and the relative positional relationship between the antenna that measures the radiated interference waves and the specimen, the upper limit of the measurement interval for the radiated interference waves by the antenna is calculated. An information processing device equipped with the following features.

[16] The measurement interval refers to the distance between adjacent measurement positions among the multiple measurement positions where the radiated interference waves are measured by the antenna.

[15] The information processing device described above.

[17] The measurement interval is calculated based on the positions of the multiple electromagnetic wave sources, their relative positions, the wavelength of the radiated interference wave, and the sampling theorem. The information processing device described in

[15] or

[16] .

[18] If the calculated maximum value of the measurement interval exceeds the calculated upper limit, the upper limit is selected as the measurement interval used in the radiation interference test for measuring the radiation interference waves. If the calculated maximum value of the measurement interval is less than or equal to the calculated upper limit, the calculated measurement interval is selected as the measurement interval used in the radiation interference test.

[17] The information processing device described above.

[19] Based on the positions of the plurality of electromagnetic wave sources and the positional relationship, a plurality of measurement positions for measuring the radiated interference wave with the antenna are calculated such that the measurement interval satisfies the sampling theorem with respect to the wavelength of the radiated interference wave, The information processing apparatus according to any one of

[15] to

[18] .

[20] The upper limit value is calculated based on statistical analysis, The information processing apparatus according to any one of

[15] to

[19] .

[21] Based on the calculated upper limit value, at least one of a distribution of electric field intensity of the radiated interference wave and a distribution of magnetic field intensity of the radiated interference wave is calculated, The information processing apparatus according to any one of

[15] to

[20] .

[22] Acquiring the at least one distribution by simulation or actual measurement, and interpolating the at least one distribution by a low-pass filter, The information processing apparatus according to

[21] .

[0198] Hitherto, the embodiments of the present disclosure have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and alterations, substitutions, deletions, and the like may be made without departing from the gist of the present disclosure.

[0199] Furthermore, a program to realize the function of any component in the device described above (for example, the radiation interference measurement device 100, controller 6, computer 7, etc.) may be recorded on a computer-readable recording medium, and the program may be loaded into a computer system and executed. Here, "computer system" includes hardware such as the OS (Operating System) and peripheral devices. Furthermore, "computer-readable recording medium" refers to portable media such as flexible disks, magneto-optical disks, ROM (Read Only Memory), CD (Compact Disk)-ROM, and storage devices such as hard disks built into a computer system. In addition, "computer-readable recording medium" also includes volatile memory (RAM (Random Access Memory)) inside a computer system that acts as a server or client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line, which holds the program for a certain period of time.

[0200] Furthermore, the above program may be transmitted from a computer system that stores the program in a memory device or the like to another computer system via a transmission medium or by transmission waves within the transmission medium. Here, the "transmission medium" used to transmit the program refers to a medium that has the function of transmitting information, such as a network (communication network) like the Internet or a communication line (communication line) like a telephone line. Furthermore, the above program may be intended to implement only a portion of the functions described above. In addition, the above program may be a so-called differential file (differential program) that can implement the functions described above in combination with a program already recorded in the computer system. [Explanation of Symbols]

[0201] 1…Test specimen, 2…Antenna, 3…Antenna mast, 4…Turntable, 5…Receiver, 6…Controller, 7…Computer, 8…Control unit, 9…Calculation processing unit, 10…Main control unit, 11…Input device, 12…Output device, 13…Storage device, 14…Bus, 15…Recording medium, 100…Radiation interference measurement device

Claims

1. On the computer, A first calculation step involves calculating an upper limit value for the measurement interval, which is the spatial distance between adjacent measurement positions among a plurality of measurement positions where the antenna measures the radiated interference waves, based on the positions of a plurality of electromagnetic wave sources corresponding to the test specimen that radiates the radiated interference waves, and the relative positional relationship between the antenna that measures the radiated interference waves and the test specimen. A storage step in which the upper limit information indicating the upper limit calculated in the first calculation step is stored in a storage unit in association with the analysis target ratio according to the relative positional relationship between the antenna and the test specimen, An upper limit value identification step, which involves identifying the upper limit value of the measurement interval corresponding to the analysis target ratio based on the upper limit value information stored in the storage unit, A second calculation step involves calculating the measurement interval based on the positions of the plurality of electromagnetic wave sources, the positional relationship, the wavelength of the radiated interference wave, and the sampling theorem. A selection step in which, if the maximum value of the measurement interval calculated by the second calculation step exceeds the upper limit value specified by the upper limit value specification step, the upper limit value specified by the upper limit value specification step is selected as the measurement interval to be used for the radiation interference test, and if the maximum value of the measurement interval calculated by the second calculation step is less than or equal to the upper limit value specified by the upper limit value specification step, the measurement interval calculated by the second calculation step is selected as the measurement interval to be used for the radiation interference test. Make it run, The aforementioned analysis target ratio is the ratio of the measurement distance corresponding to the relative positional relationship between the antenna and the test specimen to the radius of the electromagnetic wave source region corresponding to the test specimen. The first calculation step is, Identify the multiple frequencies of the aforementioned radiated interference waves, For each of the aforementioned multiple frequencies, the measurement target electric field strength distribution is estimated a predetermined number of times based on the positions of two electromagnetic wave sources randomly assigned within the electromagnetic wave source region, using the measurement condition information including the positional relationship and the Monte Carlo method. Each of the estimated predetermined number of measured electric field strength distributions is subjected to a Fourier transform to calculate a predetermined number of spatial frequency spectra. Based on the calculated number of predetermined spatial frequency spectra, the maximum spatial frequency corresponding to each of the plurality of frequencies is identified. The upper limit is calculated based on the measurement interval obtained according to the maximum spatial frequency specified for each of the plurality of frequencies. program.

2. Based on the upper limit value calculated in the first calculation step, the electric field of the radiated interference wave A third method for calculating the distribution of at least one of the intensity distribution and the magnetic field intensity distribution of the radiated interference wave. Perform the calculation step. The program according to claim 1.

3. An acquisition step of obtaining at least one of the aforementioned distributions by simulation or actual measurement, An interpolation step of interpolating at least one of the distributions using a low-pass filter, The program according to claim 2 that causes the execution of the program.

4. A first calculation step involves calculating an upper limit value for the measurement interval of the radiated interference waves by the antenna, based on the positions of multiple electromagnetic wave sources corresponding to the test specimen radiating the radiated interference waves and the relative positional relationship between the antenna that measures the radiated interference waves and the test specimen. A storage step in which the upper limit information indicating the upper limit calculated in the first calculation step is stored in a storage unit in association with the analysis target ratio according to the relative positional relationship between the antenna and the test specimen, An upper limit value identification step, which involves identifying the upper limit value of the measurement interval corresponding to the analysis target ratio based on the upper limit value information stored in the storage unit, A second calculation step involves calculating the measurement interval based on the positions of the plurality of electromagnetic wave sources, the positional relationship, the wavelength of the radiated interference wave, and the sampling theorem. A selection step in which, if the maximum value of the measurement interval calculated by the second calculation step exceeds the upper limit value specified by the upper limit value specification step, the upper limit value specified by the upper limit value specification step is selected as the measurement interval to be used for the radiation interference test, and if the maximum value of the measurement interval calculated by the second calculation step is less than or equal to the upper limit value specified by the upper limit value specification step, the measurement interval calculated by the second calculation step is selected as the measurement interval to be used for the radiation interference test. It has, The aforementioned analysis target ratio is the ratio of the measurement distance corresponding to the relative positional relationship between the antenna and the test specimen to the radius of the electromagnetic wave source region corresponding to the test specimen. The first calculation step is, Identify the multiple frequencies of the aforementioned radiated interference waves, For each of the aforementioned multiple frequencies, the measurement target electric field strength distribution is estimated a predetermined number of times based on the positions of two electromagnetic wave sources randomly assigned within the electromagnetic wave source region, using the measurement condition information including the positional relationship and the Monte Carlo method. Each of the estimated predetermined number of measured electric field strength distributions is subjected to a Fourier transform to calculate a predetermined number of spatial frequency spectra. Based on the calculated number of predetermined spatial frequency spectra, the maximum spatial frequency corresponding to each of the plurality of frequencies is identified. The upper limit is calculated based on the measurement interval obtained according to the maximum spatial frequency specified for each of the plurality of frequencies. Information processing methods.

5. A third calculation step is to calculate the distribution of at least one of the distributions of the electric field strength of the radiated interference wave and the magnetic field strength of the radiated interference wave, based on the upper limit value calculated in the first calculation step. The information processing method according to claim 4.

6. An acquisition step of obtaining at least one of the aforementioned distributions by simulation or actual measurement, An interpolation step of interpolating at least one of the distributions using a low-pass filter, The information processing method according to claim 5, having the following characteristics.

7. A first calculation unit calculates an upper limit value for the measurement interval of the radiated interference waves by the antenna, based on the positions of multiple electromagnetic wave sources corresponding to the test specimen that radiates the radiated interference waves, and the relative positional relationship between the antenna that measures the radiated interference waves and the test specimen. A storage unit stores upper limit information indicating the upper limit calculated by the first calculation unit, in association with the analysis target ratio corresponding to the relative positional relationship between the antenna and the test specimen. An upper limit value identification unit that identifies the upper limit value of the measurement interval corresponding to the analysis target ratio based on the upper limit value information stored in the storage unit, A second calculation unit calculates the measurement interval based on the positions of the plurality of electromagnetic wave sources, the positional relationship, the wavelength of the radiated interference wave, and the sampling theorem. A selection unit that, if the maximum value of the measurement interval calculated by the second calculation unit exceeds the upper limit value specified by the upper limit value specification unit, causes the upper limit value specified by the upper limit value specification unit to be selected as the measurement interval to be used for the radiation interference wave test, and if the maximum value of the measurement interval calculated by the second calculation unit is less than or equal to the upper limit value specified by the upper limit value specification unit, causes the measurement interval calculated by the second calculation unit to be selected as the measurement interval to be used for the radiation interference wave test, Equipped with, The aforementioned analysis target ratio is the ratio of the measurement distance corresponding to the relative positional relationship between the antenna and the test specimen to the radius of the electromagnetic wave source region corresponding to the test specimen. The first calculation unit is, Identify the multiple frequencies of the aforementioned radiated interference waves, For each of the aforementioned multiple frequencies, the measurement target electric field strength distribution is estimated a predetermined number of times based on the positions of two electromagnetic wave sources randomly assigned within the electromagnetic wave source region, using the measurement condition information including the positional relationship and the Monte Carlo method. Each of the estimated predetermined number of measured electric field strength distributions is subjected to a Fourier transform to calculate a predetermined number of spatial frequency spectra. Based on the calculated number of predetermined spatial frequency spectra, the maximum spatial frequency corresponding to each of the plurality of frequencies is identified. The upper limit is calculated based on the measurement interval obtained according to the maximum spatial frequency specified for each of the plurality of frequencies. An information processing device equipped with the following features.

8. The second calculation unit calculates a plurality of measurement positions for measuring the radiated interference wave by the antenna, based on the positions of the plurality of electromagnetic wave sources and the positional relationship, such that the measurement interval satisfies the sampling theorem with respect to the wavelength of the radiated interference wave. The information processing apparatus according to claim 7.

9. The system includes a third calculation unit that calculates the distribution of at least one of the distributions of the electric field strength of the radiated interference wave and the distribution of the magnetic field strength of the radiated interference wave based on the calculated upper limit value. The information processing apparatus according to claim 7.

10. The interpolation unit includes obtaining at least one of the aforementioned distributions by simulation or measurement, and interpolating at least one of the aforementioned distributions using a low-pass filter. The information processing apparatus according to claim 9.

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