JP2020106355A - Radiated emission measuring device - Google Patents

Abstract

To suppress the occurrence of a case where noise is unmeasurable.SOLUTION: A radiated emission measuring device comprises: a height change unit for changing a height with reference to the emitter of an antenna; a determination unit which, when the height is changed, determines, in accordance with a measurement plan, whether or not to change the starting point of sampling time having been set during a sample cycle and having a certain length; a sampling time change unit which, when it is determined that the starting point of sampling time be changed, adjusts the length of an adjustment time and thereby changes the starting point of sampling time so that a remainder derived by dividing the change width of starting point of sampling time by the sampling cycle is a value other than zero and the remainder is less than or equal to the sampling time; and a measurement unit for measuring, for the duration of a sampling time the starting point of which is changed by the sampling time change unit, the electric field intensity in a prescribed frequency band at a measurement point at the height with reference to the emitter of the antenna having been changed by the height change unit.SELECTED DRAWING: Figure 1

Description

The present invention relates to a radiated emission measuring device.

An electronic device may radiate a radiation interference wave that is an electromagnetic wave affecting surrounding electronic devices and communication devices. For this reason, it is now necessary to perform a radiated emission test to confirm that the electric field strength of the radiated emission is less than or equal to the allowable value of the internationally specified standard before the electronic device is shipped to the market. ..

In the radiated emission test, the electric field strength is measured by the antenna while changing the height of the radiated emission source and the azimuth of the antenna with reference to the radiation source. Explore. Then, at the position where the electric field strength is maximum, the electric field strength of the radiated interference wave is measured for a certain period of time, and it is confirmed whether or not the measured value of the electric field strength is less than or equal to the allowable value of the internationally defined standard. ..

Further, in such a radiated emission test, since it is necessary to detect the maximum electric field strength position in a wide frequency band, a spectrum analyzer capable of measuring a spectrum in a wide frequency band is used. Examples of such a spectrum analyzer include a super-heterodyne type spectrum analyzer and an FFT (Fast Fourier Transform) type spectrum analyzer.

The super-heterodyne spectrum analyzer is a kind of swept spectrum analyzer, and measures the frequency spectrum of the radiated interference wave while sweeping the frequency of the radiated interference wave measured at each sampling time with a predetermined resolution bandwidth. Therefore, when a super-heterodyne spectrum analyzer is used, the sampling period becomes longer than the sampling time.

The FFT type spectrum analyzer acquires the frequency spectrum of the radiated interference wave by performing FFT processing on the waveform of the radiated interference wave measured at the sampling time. The FFT type spectrum analyzer does not measure the electric field strength of the radiated interference wave while performing the FFT process on the waveform of the radiated interference wave. For this reason, when the FFT type spectrum analyzer is used, the sampling period becomes longer than the sampling time.

When the radiated emission measurement is performed by the above-mentioned spectrum analyzer, the time required for the radiated emission test may increase due to the long sampling period. Therefore, in order to shorten the time required for the radiated emission test, shorten the sampling time for each frequency, measure the electric field strength at a long sampling time at the frequency where the electric field strength near the above-mentioned allowable value was measured, and perform this measurement. The electric field strength is measured for a certain time at the position where the maximum electric field strength is measured by. In addition, in order to further shorten the time required for the radiated emission test, the electric field strength at each frequency may be measured while continuously operating the spectrum analyzer. In addition, the radiated emissions test does not use triggers because multiple radiated emissions measurements are performed simultaneously.

However, in the above-described measurement method, when the timing at which the radiated emission occurs and the sampling time are different, and the period at which the radiated emission occurs and the sampling period are equal, the radiated emission is not measured even once. It may end up. In order to avoid such a situation, for example, Non-Patent Document 1 describes changing the time to start the sweep, but the length of the time to change the time to start the sweep and the timing to change the time. In some cases, radiated disturbances may never be measured. Although Non-Patent Document 1 describes that the sweep time is changed, the measurement method described in Patent Document 1 may become unusable due to a change in the sampling time. is there.

The measuring method disclosed in Patent Document 1 discloses a radiated emission measuring device including a first measuring device, a second measuring device, and a control device. The first measuring device measures the electric field intensity distribution by measuring the frequency spectrum of the electric field intensity received by the antenna at the plurality of measuring points set on the surface surrounding the radiation source for the first residence time. .. The second measuring device measures the electric field intensity of the predetermined frequency received by the antenna at the measurement point where the predetermined electric field intensity at the predetermined frequency is obtained in the electric field intensity distribution measured by the first measuring device. , And is measured in real time for each second residence time. Further, the control device determines whether or not the electric field strength distribution measured by the first measuring instrument is correctly measured based on the electric field strength measured by the second measuring instrument. The second residence time is set to the same value as the first residence time.

FY2008 Information and Communications Council Report Advisory Issue No.3, "International Radio Interference Special Committee (CISPR) Standards", "Technical Conditions for Radio Frequency Interference and Immunity Measurement", Part 2, Part 3 Radiation Interfering wave measurement method

JP, 2018-169200, A

Therefore, it is an object of the present invention to provide a radiated emission measuring device capable of suppressing the occurrence of a situation where noise is not measured.

One aspect of the present invention is a height changing unit that executes a height changing process of changing a height of an antenna that receives a radiation interference wave emitted from a radiation source with respect to the radiation source, and the radiation of the antenna. If the height with respect to the source is changed, it is set during the sampling period, and a judgment process is performed according to the measurement plan to determine whether to change the start time of the sampling time having a certain length. When it is determined to change the start time of the sampling time with the determination unit, the first time after the height changing process is executed from the time when the last sampling cycle before the height changing process is completed is completed. By adjusting the length of the adjustment time provided until the start of the sampling cycle of, the remainder obtained by dividing the change width of the start time of the sampling time by the sampling cycle becomes a value other than zero, and , A sampling time changing unit that executes a sampling time changing process that changes the starting time point of the sampling time so that the remainder is equal to or less than the sampling time period, and a sampling time period when the starting time point is changed by the sampling time changing unit. Meanwhile, a measurement process of measuring the electric field strength of a predetermined frequency band at a measurement point located on a surface surrounding the radiation source at a height with the radiation source of the antenna changed by the height changing unit as a reference, It is a radiated emission measuring device provided with the measuring part to perform.

Further, in one aspect of the present invention, the radiated emission measuring device performs the height changing process, the determining process, the sampling time changing process, and the measuring process. It further comprises a repeating unit that repeats the number of times that satisfies the expression (1).

ｎ ：回数
Ｔ_Ｖ：サンプリング時間の変更幅
Ｔ ：サンプリング周期
Ｔ_Ｓ：サンプリング時間

n: number of times T _V : change width of sampling time T: sampling period T _S : sampling time

One aspect of the present invention is a height changing unit that executes a height changing process of changing a height of an antenna that receives a radiation interference wave emitted from a radiation source with respect to the radiation source, and the radiation of the antenna. If the height with respect to the source is changed, it is set during the sampling period, and a judgment process is performed according to the measurement plan to determine whether to change the start time of the sampling time having a certain length. When it is determined to change the start time of the sampling time with the determination unit, the first time after the height changing process is executed from the time when the last sampling cycle before the height changing process is completed is completed. The value obtained by dividing the sampling time by the remainder obtained by dividing the change width at the start point of the sampling time by the sampling cycle by adjusting the length of the adjustment time provided until the sampling cycle starts. Is a value other than zero and a natural number, and a sampling time changing unit that executes a sampling time changing process that changes the starting time of the sampling time so that the change width of the starting time of the sampling time is equal to or greater than the sampling time. A position on a surface surrounding the radiation source at a height based on the radiation source of the antenna changed by the height changing unit during the sampling time when the start time is changed by the sampling time changing unit. A radiated emission measuring apparatus including: a measurement unit that executes a measurement process of measuring an electric field strength in a predetermined frequency band at a measurement point.

One aspect of the present invention is a height changing unit that executes a height changing process of changing a height of an antenna that receives a radiation interference wave emitted from a radiation source with respect to the radiation source, and the radiation of the antenna. If the height with respect to the source is changed, it is set during the sampling period, and a judgment process is performed according to the measurement plan to determine whether to change the start time of the sampling time having a certain length. When it is determined to change the start time of the sampling time with the determination unit, the first time after the height changing process is executed from the time when the last sampling cycle before the height changing process is completed is completed. By randomly changing the length of the adjustment time provided up to the start of the sampling period of, the sampling time is changed to randomly change the sampling time. A surface surrounding the radiation source at a height based on the radiation source of the antenna changed by the height changing unit during the sampling time in which the start time is changed by the changing unit and the sampling time changing unit. It is a radiated interference wave measuring device, comprising: a measurement unit that executes a measurement process of measuring an electric field strength of a predetermined frequency band at a measurement point located above.

Further, in one aspect of the present invention, the sampling time changing unit randomly changes the starting time of the sampling time under the condition that the changing width of the starting time of the sampling time is longer than the sampling time.

According to the present invention, it is possible to suppress the occurrence of a situation in which noise is not measured.

It is a figure which shows an example of a structure of the radiated emission measuring device which concerns on embodiment. It is a figure which shows an example of the measurement point located on the surface which surrounds the radiation source which concerns on embodiment. It is a figure for explaining an example of a sampling time pattern concerning an embodiment. It is a figure which shows an example of the hardware constitutions of the control part which concerns on embodiment. It is a flow chart which shows an example of processing which a radiated emission measuring device concerning an embodiment performs.

[Embodiment]
The configuration of the radiated emission measuring device according to the embodiment will be described with reference to FIGS. 1 to 4. FIG. 1 is a diagram showing an example of the configuration of a radiated emission measuring device according to an embodiment.

The radiated emission measuring device 1 shown in FIG. 1 is a device used in a radiated emission test for measuring a radiated emission emitted from a radiation source 100, which is a sample, according to the EMC standard, for example. This radiated emission test has internationally defined test conditions and test methods. The radiated emission measuring device 1 is arranged in an anechoic chamber having a metal floor surface forming a ground plane. An electromagnetic wave absorber is attached to the inner wall of the anechoic chamber except the metal floor surface. Further, the radiation source 100 is, for example, an electronic device that emits a radiation interference wave.

As shown in FIG. 1, the radiated emission measuring device 1 includes an antenna 11, an antenna mast 12, a turntable 13, a drive control unit 14, a control unit 20, and a measurement unit 30.

The antenna 11 receives a radiation interference wave in a predetermined frequency band at a measurement point located on the surface surrounding the radiation source 100. FIG. 2 is a diagram showing an example of measurement points located on the surface surrounding the radiation source according to the embodiment. This surface is, for example, a side surface of a cylinder whose central axis is perpendicular to the ground plane and which internally includes the radiation source 100 and the platform 200. As shown by white circles in FIG. 2, each measurement point is defined by a first axis along the circumferential direction of the circle of the bottom surface of the cylinder and a second axis that is an axis parallel to the central axis of the cylinder. It is arranged on the defined two-dimensional Cartesian coordinates. The first axis indicates the height of each measurement point with respect to the radiation source 100. The second axis indicates the azimuth angle of each measurement point with respect to the radiation source 100. Further, the measurement points shown in FIG. 2 are arranged at equal intervals in a direction parallel to the first axis and a direction parallel to the second axis. However, the measurement points shown in FIG. 2 may be arranged at arbitrary intervals in at least one of the direction parallel to the first axis and the direction parallel to the second axis.

The antenna mast 12 supports the antenna 11 in a vertically movable form and is arranged at a predetermined distance from the radiation source 100. The turntable 13 is a disc-shaped turntable provided on the ground plane and can rotate about an axis perpendicular to the ground plane. The radiation source 100 is placed on a table 200 placed on the turntable 13.

The drive control unit 14 includes a height changing unit 141 and an azimuth changing unit 142. The height changing unit 141 executes a height changing process for changing the height of the antenna 11 that receives the radiation interference wave radiated by the radiation source 100 with respect to the radiation source 100. Specifically, the height changing unit 141 drives the antenna mast 12 to move the antenna 11 up and down to fix the antenna 11 at a predetermined height. The azimuth changing unit 142 executes azimuth changing processing for changing the azimuth of the antenna 11 with respect to the radiation source 100. Specifically, the azimuth changing unit 142 drives the turntable 13 to rotate the radiation source 100 and the table 200 by 360 degrees after the height changing unit 141 fixes the antenna 11 at a predetermined height.

The control unit 20 includes a determination unit 201, a sampling time changing unit 202, and a repeating unit 203.

When the height of the antenna 11 with respect to the radiation source 100 is changed, the determination unit 201 is set during the sampling period and determines whether to change the start time of the sampling time having a certain length. The determination process for determining according to the measurement plan is executed.

Sampling is a process in which the radiated emission measuring device 1 measures the electric field strength of the radiated emission. The sampling period is the time from the start of one sampling to the start of the next sampling. Moreover, the sampling period has a fixed length. The sampling time is a time period in which sampling is performed in a predetermined frequency band in each sampling cycle, and has a fixed length.

The waiting time is composed of two times. The first time is from the state where the antenna 11 is aligned with the measurement point where the sampling is completed to the state where the antenna 11 is aligned with the measurement point where the next sampling is performed. It is time to drive the table 13. The second time is required for the waiting time until the vibration of the antenna 11 subsides after the driving of the antenna mast 12 or the turntable 13 is completed, and the operation of the hardware and software included in the radiated emission measuring apparatus 1. It's time.

The adjustment time is provided from the time when the last sampling cycle before the height changing process is completed to the time when the first sampling period after the height changing process is started. It's time. The adjustment time is the time whose length is adjusted by the sampling time changing unit 202 in order to determine the change width at the start point of the sampling time in the sampling time changing process executed by the sampling time changing unit 202. Zero if no processing is performed.

The measurement plan defines a height changing process involving a sampling time changing process executed by the sampling time changing unit 202 after the height changing process among the height changing processes executed by the height changing unit 141 multiple times. ing. For example, when the measurement of the electric field strength is executed in a predetermined frequency band for all the measurement points shown in FIG. 2, the height changing unit 141 executes the height changing process nine times. The measurement plan stipulates how many times of the height change processing of the nine times the sampling time change processing should be executed before the height change processing, for example, the height of the third time, the fifth time, and the eighth time. It stipulates that the sampling time changing process is executed after the changing process. In this case, the determination unit 201 determines to execute the sampling time changing process after the third, fifth, and eighth height changing processes.

The measurement plan may be input by the user before the electric field strength measurement is started or while the electric field strength measurement is being executed, or may be automatically generated by the radiated emission measuring apparatus 1. Good.

Further, the determination unit 201 determines whether or not there is a measurement point at which the measurement of the electric field strength is not executed. Specifically, the determination unit 201 determines whether or not there is a measurement point at which the height of the antenna 11 is changed to measure the electric field strength.

When it is determined that the start time of the sampling time is changed, the sampling time changing unit 202 determines whether to change the height change process after the last sampling period before the height change process is completed. By adjusting the length of the adjustment time provided until the start of the first sampling period, the remainder obtained by dividing the change width at the start of the sampling time by the sampling period becomes a value other than zero, and , Sampling time change processing for changing the start time of the sampling time so that the remainder is equal to or less than the sampling time is executed. This sampling time changing process is executed under the condition that the following expression (2) including the sampling period T, the sampling time T _S , and the change width T _V at the start point of the sampling time is satisfied.

FIG. 3 is a diagram for explaining an example of the sampling time pattern according to the embodiment. Specifically, FIG. 3A is a diagram showing an example of a case where the start time of the sampling time T _S coincides with the start time of the sampling period T. 3 (b) is a diagram showing an example of a case where the start point of the sampling time T _S is equal to the time of the lapse of time equal from the starting point to the sampling time T _S of the sampling period T. 3 (c) is a diagram showing an example of a case where the start point of the sampling time T _S is equal to the time of twice the time has elapsed sampling time T _S from the start of the sampling period T. Figure 3 (d) is a diagram showing an example of a case where the start point of the sampling time T _S is equal to the time of three times the time has elapsed sampling time T _S from the start of the sampling period T. In the example shown in FIG. 3, it is assumed that the sampling cycle T is equal to the noise generation cycle T _{N in} which noise to be measured is generated. However, the sampling period T and the noise generation period T _N may be different.

As an example of the sampling time changing process that satisfies the above equation (2), the case shown in FIG. 3A, the case shown in FIG. 3B, the case shown in FIG. In the order shown in (), there is a process of changing the sampling time T _S start time, that is, the sampling time pattern. In the case shown in FIG. 3A and the case shown in FIG. 3B, the sampling time T _S and the timing at which the noise N occurs do not overlap. Further, in the case shown in FIG. 3C, the sampling time T _S and the timing at which the noise N occurs are only slightly overlapped. On the other hand, in the case shown in FIG. 3D, the sampling time T _S and the timing at which the noise N occurs overlap.

When the sampling time pattern shown in FIG. 3A is changed to the sampling time pattern shown in FIG. 3B, the adjustment time is equal to the sampling time T _S plus an integral multiple of the sampling period T. Become. This also applies to the case where the sampling time pattern shown in FIG. 3B is changed to the sampling time pattern shown in FIG. Further, for example, when the sampling time pattern shown in FIG. 3A is changed to the sampling time pattern shown in FIG. 3C, the adjustment time is twice the sampling time T _{S and} is an integer of the sampling cycle T. It will be equal to the doubled time. This also applies to the case where the sampling time pattern shown in FIG. 3B is changed to the sampling time pattern shown in FIG. 3D.

The repeating unit 203 executes the height changing process, the determining process, the sampling time changing process, and the measuring process described later, so that the process is repeated n times the number of times satisfying the following formula (3). The interference wave measuring device 1 is controlled.

The measurement unit 30 is, for example, a superheterodyne type spectrum analyzer or an FFT type spectrum analyzer. The measuring unit 30 surrounds the radiation source 100 at a height based on the radiation source 100 of the antenna 11 changed by the height changing unit 141 during the sampling time whose start time is changed by the sampling time changing unit 202. A measurement process of measuring the electric field strength of a predetermined frequency band at the measurement point located above is executed. Then, the measuring unit 30 measures the electric field strength for a certain period of time at the measurement point where the maximum electric field strength is measured. It is confirmed whether or not the electric field strength at the measurement point is below the allowable value of the internationally defined standard. However, the measurement unit 30 performs sampling regardless of the positional relationship with the measurement point, and stores the data indicating the measured value of the electric field strength in the storage medium when the height and azimuth of the antenna 11 match the measurement point. Good.

FIG. 4 is a diagram illustrating an example of the hardware configuration of the control unit according to the embodiment. As shown in FIG. 4, the control unit 20 includes a main control unit 210, an input device 220, an output device 230, a storage device 240, and a bus 250.

The main control unit 210 includes a CPU (Central Processing Unit) and a RAM (Random Access Memory), controls transmission/reception of data among the input device 220, the output device 230, and the storage device 240, and outputs the output device 230, The operation of the storage device 240 is controlled.

The input device 220 is a device used for inputting data necessary for operating the radiated emission measuring device 1, for example, a keyboard, a mouse, or a touch panel.

The output device 230 is a device used for outputting information related to the operation of the radiated emission measuring device 1, for example, a display.

The storage device 240 is a device used to store data, for example, a hard disk device or an optical disk device. The storage device 240 also includes a storage medium 245, stores data in the storage medium 245, and reads data from the storage medium 245. The storage medium 245 is a storage medium used to store data, for example, a hard disk or an optical disc. In addition, the storage medium 245 may store a program that realizes each of the determination unit 201, the sampling time changing unit 202, and the repeating unit 203. In this case, the main control unit 210 realizes the functions of the determination unit 201, the sampling time changing unit 202, and the repeating unit 203 by reading and executing these programs.

The bus 250 connects the main controller 210, the input device 220, the output device 230, and the storage device 240 so that they can communicate with each other.

Next, an example of the operation of the radiated emission measuring device according to the embodiment will be described with reference to FIG. FIG. 5 is a flowchart showing an example of processing executed by the radiated emission measuring apparatus according to the embodiment.

In step S10, the radiated emission measuring device 1 receives an input of measurement conditions. The measurement conditions here include, for example, a frequency band for measuring electric field strength, a measurement range in the height direction with respect to the ground plane, an interval between measurement points in the height direction, a measurement range in the azimuth direction, and an azimuth direction. The measurement point interval, the sampling time, the detection method of the measurement unit 30, the frequency resolution bandwidth, and the above-described measurement plan.

In step S20, the drive control unit 14 changes the height of the antenna 11 to a height at which the electric field strength of the measurement point arranged at the lowest height can be measured, and the antenna 11 is arranged at the position with the smallest azimuth angle. The turntable 13 is rotated to an angle at which the electric field strength at the existing measurement point can be measured.

In step S30, the radiated emission measuring device 1 measures the electric field strength in a predetermined frequency band at each measurement point while rotating the turntable 13 while maintaining the height of the antenna 11 with respect to the radiation source 100. Execute.

In step S40, the drive control unit 14 changes the height of the antenna 11 with the radiation source 100 as a reference.

In step S50, the determination unit 201 determines whether to change the start time point of the sampling time in the sampling cycle. When the determination unit 201 determines to change the start time of the sampling time in the sampling cycle (step S50: YES), the process proceeds to step S60 and determines not to change the start time of the sampling time in the sampling cycle (step S50). (S50: NO), the process proceeds to step S70.

In step S60, the sampling time changing unit 202 executes a sampling time changing process for changing the starting point of the sampling time in the sampling cycle.

In step S70, the radiated emission measuring apparatus 1 measures the electric field strength in a predetermined frequency band at each measurement point while rotating the turntable 13 while maintaining the height of the antenna 11 relative to the radiation source 100. Execute.

In step S80, the determination unit 201 determines whether or not there is a measurement point at which the measurement of electric field strength is not executed. When the determination unit 201 determines that there is a measurement point at which the electric field strength measurement is not performed (step S80: YES), the process returns to step S40, and there is no measurement point at which the electric field strength measurement is not performed. If determined (step S80: NO), the process is ended.

Note that step S40 may be executed simultaneously with step S60. Moreover, step S40 may be performed between step S60 and step S70. In this case, when the determination unit 201 determines that the start time point of the sampling time in the sampling cycle is not changed (step S50: NO), the process proceeds to step S40 or step S70.

The radiated emission measuring device 1 according to the embodiment has been described above. When it is determined that the start time of the sampling time is changed according to the measurement plan, the radiated emission measuring device 1 samples the change width at the start time of the sampling time between the start and the end of the height change process. A sampling time changing process is executed to change the starting point of the sampling time so that the remainder divided by the cycle becomes a value other than zero and the remainder becomes equal to or less than the sampling time.

Therefore, the radiated interference wave measuring device 1 can improve the probability that the sampling time and the timing at which noise to be measured occurs overlap. That is, the radiated emission measuring apparatus 1 determines the sampling time and the timing at which noise occurs when the electric field strength is measured at all the measurement points shown in FIG. 3 without changing the start time of the sampling time. The sampling time and the timing at which noise is generated can be overlapped with the probability that the number of times when the starting point of the sampling time is changed is multiplied by the number of times when the start time of the sampling time is changed. For example, when the start time of the sampling time is changed three times, the probability that the two overlap will be shown in FIG. 3 with one of the sampling time patterns shown in FIGS. 3A to 3D. When the measurement of the electric field strength is performed at all the measurement points, the probability that the two overlap will be four times.

Therefore, the radiated emission measuring device 1 can suppress the occurrence of a situation in which noise is not measured. Further, since the radiated emission measuring device 1 keeps the length of the sampling time constant in the sampling time changing process, it is possible to suppress the occurrence of a situation in which the noise sampling time becomes long. Further, since the radiated emission measuring device 1 executes the sampling time changing process from the start to the end of the height changing process, the height of the antenna 11 is different from that of the radiation source 100. It is possible to efficiently measure the electric field strength at.

The radiated emission measuring apparatus 1 executes the height changing process, the determining process, the sampling time changing process, and the measuring process by repeating n times the number of times satisfying the above-described formula (3). Causes the entire sampling time to overlap the sampling time at least once. Therefore, the radiated interference wave measuring device 1 can surely overlap the sampling time and the timing at which noise to be measured occurs, and suppress the occurrence of a situation in which noise is not measured.

In the above-described embodiment, the height changing unit 141 drives the antenna mast 12 to change the height of the antenna 11 based on the height of the radiation source 100. However, the present invention is not limited to this. .. For example, the height changing unit 141 may change the height of the antenna 11 based on the height of the radiation source 100 by moving the turntable 13 up and down. Alternatively, the height changing unit 141 may change the height of the antenna 11 based on the height of the radiation source 100 by performing both the raising and lowering of the antenna mast 12 and the raising and lowering of the turntable 13.

In the above-described embodiment, the case where the sampling time changing unit 202 changes the start time point of the sampling time so as to satisfy the above-described formula (2) has been described as an example, but the present invention is not limited to this.

When the sampling time changing unit 202 determines that the starting time of the sampling time is changed, the sampling time changing unit 202 adjusts the length of the adjustment time described above to perform sampling with the remainder obtained by dividing the change width at the starting time of the sampling time by the sampling cycle. Sampling time change processing may be executed to change the start time of the sampling time so that the value obtained by dividing the time becomes a value other than zero and a natural number, and the change width of the start time of the sampling time is equal to or greater than the sampling time. .. This sampling time changing process is executed under the condition that the following expression (2) including the sampling period T, the sampling time T _S , and the change width T _V at the start point of the sampling time is satisfied.

As a result, the radiated emission measuring device 1 avoids the start time of the sampling time in the sampling cycle from being the same, and improves the probability that the sampling time and the timing at which noise to be measured occurs overlap. It is possible to suppress the occurrence of a situation where noise is not measured. Also in this case, since the radiated emission measuring device 1 keeps the sampling time length constant in the sampling time changing process, it is possible to suppress the occurrence of a long noise sampling time.

Alternatively, when the sampling time changing unit 202 determines that the starting time of the sampling time is changed, the sampling time changing unit 202 randomly changes the length of the adjustment time described above to randomly change the starting time of the sampling time. You may perform a time change process. As a result, the radiated interference wave measuring device 1 can improve the probability that the sampling time and the timing at which noise to be measured occurs overlap, and suppress the occurrence of a situation in which noise is not measured.

Further, in this case, it is preferable that the sampling time changing unit 202 randomly changes the starting time of the sampling time under the condition that the change width of the starting time of the sampling time is longer than the sampling time. That is, it is preferable that the sampling time changing unit 202 set the sampling time to a time that does not overlap with the time when the electric field strength was measured in the past in the sampling cycle. As a result, the radiated emission measuring device 1 can further improve the probability that the sampling time and the timing at which noise to be measured occurs overlap, and suppress the occurrence of a situation in which noise is not measured.

Further, a program for realizing each function of the drive control unit 14, the control unit 20, and the measurement unit 30 according to the above-described embodiment is recorded in a computer-readable recording medium, and the program recorded in this recording medium is stored in a computer. The processing may be performed by loading the system and executing it.

The computer system referred to here may include an operating system (OS) or hardware such as peripheral devices. The computer-readable recording medium is, for example, a writable nonvolatile memory such as a floppy disk, a magneto-optical disk, a ROM (Read Only Memory), a flash memory, a portable medium such as a DVD (Digital Versatile Disc), and the like. A storage device such as a hard disk built in a computer system, or a volatile memory inside a computer system that functions as a server or a client when the program is transmitted via a network or a communication line, and holds the program for a certain period of time. Also includes.

Further, the above-described program may be transmitted from a computer system that stores the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the transmission medium for transmitting the program refers to a medium having a function of transmitting information, such as a network such as the Internet or a communication line such as a telephone line.

Further, the above-mentioned program may be a program for realizing a part of the above-mentioned functions, or a program that can realize the above-mentioned functions in combination with a program already recorded in the computer system, that is, a so-called difference program. It may be. The above-described program is read and executed by a processor such as a CPU (Central Processing Unit) included in the computer, for example.

As described above, the embodiment of the present invention has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and various modifications, replacements or designs are possible without departing from the gist of the present invention. You can make changes. Further, the configurations described in the above-described embodiments may be combined.

DESCRIPTION OF SYMBOLS 1... Radiated emission measuring device, 11... Antenna, 12... Antenna mast, 13... Turntable, 14... Drive control part, 141... Height change part, 142... Direction change part, 20... Control part, 201... Judgment part , 202... Sampling time changing unit, 203... Repeating unit, 210... Main control unit, 220... Input device, 230... Output device, 240... Storage device, 245... Storage medium, 250... Bus, 30... Measuring unit, 100... Radiant source, 200...stand

Claims (5)

A height changing unit that executes a height changing process that changes the height of the antenna that receives the radiated interference wave radiated by the radiation source, with reference to the radiation source,
If the height of the antenna with respect to the radiation source is changed, it is set during the sampling period, and it is determined according to the measurement plan whether to change the start time of the sampling time having a fixed length. A determination unit that executes determination processing,
If it is determined to change the start time of the sampling time, the first sampling period after the height changing process is executed from the time when the last sampling period before the height changing process is completed is completed. By adjusting the length of the adjustment time provided up to the start time, the remainder obtained by dividing the change width at the start time of the sampling time by the sampling cycle becomes a value other than zero, and the remainder is A sampling time changing unit that executes a sampling time changing process that changes the starting time point of the sampling time so as to be equal to or less than the sampling time,
The antenna is positioned on the surface surrounding the radiation source at a height based on the radiation source of the antenna, which is changed by the height changing unit, during the sampling time when the start time is changed by the sampling time changing unit. A measurement unit that executes a measurement process to measure the electric field strength of a predetermined frequency band at the measurement point,
Radiated emission measuring device comprising. The height changing process is executed, the determining process is executed, the sampling time changing process is executed, and the process of executing the measuring process is further repeated a number of times satisfying the following formula (1).
The radiated emission measuring device according to claim 1.

n: number of times T _V : change width of sampling time T: sampling period T _S : sampling time A height changing unit that executes a height changing process that changes the height of the antenna that receives the radiated interference wave radiated by the radiation source, with reference to the radiation source,
If the height of the antenna with respect to the radiation source is changed, it is set during the sampling period, and it is determined according to the measurement plan whether to change the start time of the sampling time having a fixed length. A determination unit that executes determination processing,
If it is determined to change the start time of the sampling time, the first sampling period after the height changing process is executed from the time when the last sampling period before the height changing process is completed is completed. By adjusting the length of the adjustment time provided up to the start time, the value obtained by dividing the sampling time by the remainder obtained by dividing the change width at the start point of the sampling time by the sampling cycle is zero or a natural number. And a sampling time changing unit that executes a sampling time changing process for changing the starting time of the sampling time so that the change width of the starting time of the sampling time is equal to or more than the sampling time.
The antenna is positioned on the surface surrounding the radiation source at a height based on the radiation source of the antenna, which is changed by the height changing unit, during the sampling time when the start time is changed by the sampling time changing unit. A measurement unit that executes a measurement process to measure the electric field strength of a predetermined frequency band at the measurement point,
Radiated emission measuring device comprising. A height changing unit that executes a height changing process that changes the height of the antenna that receives the radiated interference wave radiated by the radiation source, with reference to the radiation source,
If the height of the antenna with respect to the radiation source is changed, it is set during the sampling period, and it is determined according to the measurement plan whether to change the start time of the sampling time having a fixed length. A determination unit that executes determination processing,
If it is determined to change the start time of the sampling time, the first sampling period after the height changing process is performed from the time when the last sampling period before the height changing process is completed is By randomly changing the length of the adjustment time provided up to the start time, a sampling time changing unit that executes a sampling time changing process that randomly changes the starting time of the sampling time,
The antenna is positioned on the surface surrounding the radiation source at a height based on the radiation source of the antenna, which is changed by the height changing unit, during the sampling time when the start time is changed by the sampling time changing unit. A measurement unit that executes a measurement process to measure the electric field strength of a predetermined frequency band at the measurement point,
Radiated emission measuring device comprising. The sampling time changing unit randomly changes the starting time of the sampling time under the condition that the changing width of the starting time of the sampling time is longer than the sampling time.
The radiated emission measuring device according to claim 4.

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