JPH11133080A - Electromagnetic interference wave measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic interference wave measuring device that can specify the direction of the transmission source of electromagnetic waves that causes an electronic device to fail. SOLUTION: An external electromagnetic wave is received by antennas 1 and 2 with a delay time of t1, reception signals are A/D-converted by digitizers 3 and 4 and are stored at memories 5 and 6, respectively, external electromagnetic wave data read from the memory 5 are subjected to frequency analysis by a frequency analyzer 7, noise generation time is read from a clocking equipment 10 by a CPU 9 when it is judged that a preset, specific frequency component exceeds an allowable level and is received by comparison judging equipment 8, and the direction of the transmission source of external electromagnetic waves is specified as either of two directions based on the delay time difference between the reception signal of the antenna 1 being recorded and stored in the memory 5 and the reception signal of the antenna 2 being recorded and stored in the memory 6, thus specifying the transmission direction of noise that interferes with an electronic device and eliminating troubles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic interference wave measuring device for measuring an electromagnetic interference wave which causes a failure of an electronic device from an external electromagnetic wave.

[0002]

2. Description of the Related Art In recent electronic devices, the immunity to electromagnetic interference has been reduced due to the higher speed and lower power operation of semiconductor elements. Radio waves such as amateur radio, CB radio, and radio broadcasting exist, and these radio waves cause failures such as malfunctions of electronic devices. JP-A-6-32
Japanese Patent No. 4098 discloses that when an electromagnetic wave having a frequency component equal to or higher than a predetermined distribution level is detected in a designated frequency band, the detection time and the electromagnetic wave are automatically recorded and compared with the occurrence of electromagnetic interference. An electromagnetic interference wave measuring device for estimating a frequency characteristic and a generation source of an electromagnetic wave causing a disturbance is disclosed.

[0003]

SUMMARY OF THE INVENTION The aforementioned Japanese Patent Laid-Open No. 6-32 is disclosed.
The electromagnetic interference wave measuring device disclosed in Japanese Patent No. 4098 can know the frequency characteristics of an electromagnetic wave that causes a disturbance and estimate the source, but cannot know the direction of the source of the electromagnetic wave.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned current situation of measuring electromagnetic interference waves, and has as its object to specify the direction of the source of electromagnetic waves that may cause a failure in an electronic device. It is an object of the present invention to provide an electromagnetic interference wave measuring device.

[0005]

In order to achieve the above-mentioned object, the invention according to claim 1 is a first invention for receiving an external electromagnetic wave.
Antenna, first storage means for recording and storing the external electromagnetic wave received by the first antenna, and second storing means for receiving the external electromagnetic wave with a delay of a predetermined time from the first antenna.
Antenna, second storage means for recording and storing the external electromagnetic wave received by the second antenna, frequency analysis means for frequency-analyzing the external electromagnetic wave, and a predetermined frequency of the electromagnetic wave frequency-analyzed by the frequency analysis means. Determining means for determining whether the component has exceeded a preset allowable level;
When the determining means determines that the predetermined frequency component of the extraneous electromagnetic wave exceeds the allowable level, the first
And a calculating means for calculating the transmission direction of the external electromagnetic wave based on the time delay of the external electromagnetic wave stored in the second storing means.

According to another aspect of the present invention, a first antenna for receiving an external electromagnetic wave and a first storage for recording and storing the external electromagnetic wave received by the first antenna are provided. Means, a second antenna for receiving the external electromagnetic wave with a first predetermined time delay from the first antenna, and a second storage means for recording and storing the external electromagnetic wave received by the second antenna A third antenna for receiving the external electromagnetic wave with a delay of a second predetermined time relative to the second antenna, a third storage unit for recording and storing the external electromagnetic wave received by the third antenna, Frequency analyzing means for performing frequency analysis of an external electromagnetic wave, determining means for determining whether or not a predetermined frequency component of the electromagnetic wave whose frequency has been analyzed by the frequency analyzing means has exceeded a preset allowable level; and If it is determined that the predetermined frequency component of the extraneous electromagnetic wave has exceeded the allowable level, the extraneous energy stored in the first storage means, the second storage means, and the third storage means is determined. Calculating means for calculating the transmitting direction of the foreign electromagnetic wave based on the time delay of the electromagnetic wave.

[0007] Similarly, in order to achieve the above object, a third aspect of the present invention measures the time when the extraneous electromagnetic wave exceeds the allowable level with respect to the first or second aspect of the invention. It is characterized in that a timing means is provided.

[0008] Similarly, in order to achieve the above object, the invention according to claim 4 is different from the invention according to claim 1 in that a predetermined amount of the external electromagnetic wave is transmitted to the first antenna and the second antenna. A shielding means for shielding incident light from one direction is provided over the first antenna and the second antenna.

[0009] Similarly, in order to achieve the above object, the invention according to claim 5 is different from the invention according to claim 1 or 2 in that at least one of the first antenna and the second antenna, Alternatively, an electromagnetic wave absorber that absorbs an external electromagnetic wave is provided near at least one of the first antenna, the second antenna, and the third antenna.

[0010] Similarly, in order to achieve the above object, the invention according to claim 6 is different from the invention according to claim 1 or 2 in that the first antenna, the second antenna, and the third antenna are provided. Antenna correction means for correcting a phase variation due to the frequency of the antenna.

[0011] Similarly, in order to achieve the above object, according to a seventh aspect of the present invention, in accordance with the first or the second aspect of the present invention, the result of the arithmetic operation by the arithmetic means is stored as a spectrum pattern. Means are provided.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing the configuration of the present embodiment, FIG. 2 is a characteristic diagram showing the waveform of an external electromagnetic wave received in the present embodiment, and FIG. 3 is a diagram showing the calculation of the transmission direction of the external electromagnetic wave in the present embodiment. FIG.

In this embodiment, as shown in FIG. 1, an antenna 1 for receiving an external electromagnetic wave and an antenna 2 for receiving the external electromagnetic wave with a delay of a predetermined time t1 from the antenna 1 are provided. 1 is connected to a digitizer 3 for AD-converting a received signal, and the digitizer 3 is connected to a memory 5 for recording and storing an output signal of the digitizer 3. The antenna 2 is connected to a digitizer 4 for AD-converting a received signal, and the digitizer 4 is connected to a memory 6 for recording and storing an output signal of the digitizer 4.

The output terminals of the memories 5 and 6 are connected to a frequency analyzer 7 for frequency-analyzing the external electromagnetic wave data read from the memory 5 or the memory 6, and the frequency analyzer 7 is connected to the frequency-analyzed external electromagnetic wave data. Is connected to a comparison / determination unit 8 which determines whether or not the predetermined frequency component exceeds a predetermined allowable level. Further, in the present embodiment, a CPU 9 for controlling the entire operation is provided, and the CPU 9 includes a frequency analyzer 7 and a comparison / determination unit 8.
And a timer 10 for measuring the time.

The operation of the embodiment having such a configuration will be described. In the present embodiment, the antenna 1 shown in FIG.
An external electromagnetic wave having a waveform as shown in FIG. 2A is received, and the received signal is AD-converted by the digitizer 3 and then recorded and stored in the memory 5. On the other hand, as shown in FIG. This external electromagnetic wave is received by the antenna 2 with a delay of time t1 from the reception of the received signal, and the received signal is recorded and stored in the memory 6 after AD conversion by the digitizer 4.

In response to a command from the CPU 9, the memory 5
The external electromagnetic wave data read from the
The frequency of the external electromagnetic wave data subjected to the frequency analysis is determined by the comparison / determination unit 8 to determine whether or not a predetermined frequency component of the externally analyzed electromagnetic wave data exceeds a predetermined allowable level. If so, a noise detection signal is input from the comparison / determination unit 8 to the CPU 9.

Based on the detection signal, the CPU 9 captures the time of occurrence of noise from the timer 10 and calculates the time difference between the external electromagnetic wave data recorded and stored in the memory 5 and the external electromagnetic wave data recorded and stored in the memory 6. On the basis of,
The calculation of the direction of the source of the external electromagnetic wave which becomes noise is performed.

In this calculation by the CPU 9, as shown in FIG.
And a position corresponding to an intersection of a circle A2 having a radius r1 that is larger than the reference radius r0 by a distance corresponding to the delay time t1 with the antenna 2 as a center.
It is determined that 2, 13 exist. In this case, the reference radius r
Since 0 is not measured, the source of the external electromagnetic wave is calculated only in the direction, and is specified as the y1 direction or the y2 direction shown in FIG.

As described above, according to the present embodiment, a foreign electromagnetic wave is received by the antenna 1 and the antenna 2 with a delay of the delay time t1, and the received signal is frequency-analyzed by the frequency analyzer 7 and set in advance. When the comparison / determination unit 8 determines that the predetermined frequency component has been received beyond the prescribed allowable level, the CPU 9 causes the memory 5 to receive the predetermined frequency component.
The direction of the source of the external electromagnetic wave is specified in one of two directions based on the delay time difference between the reception signal of the antenna 1 stored in the memory 6 and the reception signal of the antenna 2 stored in the memory 6. Therefore, it is possible to specify the direction of the noise that causes a failure in the electronic device and remove the failure.

[Second Embodiment] A second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a block diagram showing a configuration of the present embodiment, FIG. 5 is an explanatory diagram showing a configuration of a main part of the present embodiment, and FIG. 6 is an explanatory diagram showing an electromagnetic wave shielding operation of the present embodiment.

In this embodiment, as shown in FIG. 4 and FIG. 5, the antenna 1 and the antenna 2 are moved in a predetermined direction from the first embodiment already described with reference to FIG. Electromagnetic wave shielding plate 11 for blocking the incidence of foreign electromagnetic waves
Are provided over the antenna 1 and the antenna 2. The configuration of the other parts of the present embodiment is the same as that of the first embodiment already described, and will not be described again.

The operation of this embodiment having such a configuration will be described. In the present embodiment, as shown in FIG. 6, an external electromagnetic wave from the transmission source 13 is incident on the antennas 1 and 2 with a delay difference of a predetermined time t1, and the digitizer is used in the same manner as in the first embodiment. The received signals that have been A / D converted in 3 and 4 are recorded and stored in the memory 5 and the memory 6, respectively.
Next, the external electromagnetic wave data read from the memory 5 is frequency-analyzed by the frequency analyzer 7 in accordance with a command from the CPU 9, and a predetermined frequency component of the frequency-analyzed external electromagnetic wave data is compared with the comparison / determination unit 8. Thus, a comparison is made as to whether or not the level exceeds a preset allowable level. If the level exceeds the allowable level, a noise detection signal is input from the comparison / determination unit 8 to the CPU 9.

The CPU 9 fetches the time of occurrence of noise from the timer 10 in response to the detection signal, and receives the external electromagnetic wave data recorded and stored in the memory 5 and the memory 6.
Is calculated based on the time difference from the external electromagnetic wave data recorded and stored in the memory. In this case, in this embodiment, in the calculation process, the transmission of FIG. The source 12 is set as a spoofed transmission source, and the direction y2 of the transmission source 13 of the external electromagnetic wave is uniquely calculated.

As described above, according to the present embodiment, an external electromagnetic wave whose incidence from one direction is prohibited is received by antennas 1 and 2 with a delay of delay time t1, and the received signal is subjected to frequency analysis. When the frequency is analyzed by the detector 7 and the comparison / determination unit 8 determines that the predetermined frequency component set in advance has been received beyond the specified allowable level, the CPU 9 records and stores the frequency component in the memory 5. The direction of the source of the external electromagnetic wave is specified in one direction based on the delay time difference between the received signal of the antenna 1 and the received signal of the antenna 2 recorded and stored in the memory 6, so that the electronic device may be damaged. It is possible to more accurately specify the direction of the noise to be given and to remove the obstacle.

Third Embodiment A third embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a block diagram showing the configuration of the present embodiment, and FIG. 8 is an explanatory diagram showing the operation of the present embodiment.

In this embodiment, as shown in FIGS. 7 and 8 (b), a radio wave absorber 17 for absorbing an external electromagnetic wave is provided near at least one of the antennas 1 and 2. The configuration of other parts of the present embodiment is as follows.
Since it is the same as that of the first embodiment already described, the description will not be repeated.

The operation of this embodiment having such a configuration will be described. Generally, when an electromagnetic wave is received by an antenna, as shown in FIG. 8A, if an electromagnetic wave reflector 19 is present to reflect the electromagnetic wave to the antenna 1, for example, the electromagnetic wave 20 from the electromagnetic wave source 13 is directly transmitted. In addition to those incident on the antenna 1, there are reflected electromagnetic waves 22 reflected and incident on the electromagnetic wave reflector 19. In the present embodiment, since the direction of the source 13 of the external electromagnetic wave is measured,
The presence of the reflected electromagnetic wave 22 in addition to the electromagnetic wave 20 directly incident on the antenna 1 has an adverse effect on the measurement of the direction of the source 13 of the external electromagnetic wave. On the other hand, in the present embodiment, as shown in FIG. 8B, the radio wave absorber 17 disposed near the antenna 1 absorbs the electromagnetic wave 20.
The reflected electromagnetic wave from the electromagnetic wave reflector 19 is prevented from entering the antenna 1.

The other operations of the present embodiment are the same as the operations of the first embodiment already described, and will not be described again.

As described above, according to the present embodiment, a foreign electromagnetic wave is received by the antennas 1 and 2 with a delay time t1, and the radio wave absorber 17 provided near at least one of the antennas 1 and 2 is provided. Thus, the reception is performed in a state where the electromagnetic wave reflected by the electromagnetic wave reflector 19 is prevented, the received signal is frequency-analyzed by the frequency analyzer 7, and the predetermined frequency component set in advance exceeds the specified allowable level. When the signal is received by the comparator / determiner 8, the CPU 9 delays the reception signal of the antenna 1 recorded and stored in the memory 5 from the reception signal of the antenna 2 recorded and stored in the memory 6 by the CPU 9. Since the direction of the source of the external electromagnetic wave is specified in one of the two directions based on the time difference, it is possible to specify the direction of transmission of the noise that may interfere with the electronic device accurately. It is possible to perform the removal of the fault.

[Fourth Embodiment] A fourth embodiment of the present invention will be described with reference to FIGS. FIG. 9 is a block diagram showing the configuration of the present embodiment, and FIG. 10 is a diagram for explaining the principle of calculation of the transmission direction of an external electromagnetic wave according to the present embodiment.

In this embodiment, as shown in FIG. 9, the external electromagnetic wave is delayed from the antenna 2 by a predetermined time t2 with respect to the first embodiment already described with reference to FIG. An antenna 14 for receiving the received signal is provided. The antenna 14 is connected to a digitizer 15 for AD-converting the received signal. The digitizer 15 is connected to a memory 16 for recording and storing an output signal of the digitizer 15. It is connected to the analyzer 7.

The configuration of the other parts of the present embodiment is the same as that of the first embodiment already described, and will not be described again.

The operation of this embodiment having such a configuration will be described. In this embodiment, a foreign electromagnetic wave is received by antenna 1, a foreign electromagnetic wave is received by antenna 2 with a delay of time t 1 from antenna 1, and a further delay by antenna 14 by time t 2 with antenna 14. And the external electromagnetic wave is received, and the antennas 1, 2, 14
Are received by digitizers 3, 4 and 15 respectively.
After the conversion, they are recorded and stored in the memories 5, 6, and 16, respectively.

Further, the memory 5 is controlled by a command from the CPU 9.
The external electromagnetic wave data read from the
The frequency of the external electromagnetic wave data subjected to the frequency analysis is determined by the comparison / determination unit 8 to determine whether or not a predetermined frequency component of the externally analyzed electromagnetic wave data exceeds a predetermined allowable level. If so, a noise detection signal is input from the comparison / determination unit 8 to the CPU 9.

The CPU 9 fetches the noise occurrence time from the timer 10 based on the detection signal, and
Based on the time difference between the external electromagnetic wave data recorded and stored in the storage unit 16, the direction of the source of the external electromagnetic wave which becomes noise is calculated.

In this calculation by the CPU 9, as shown in FIG.
1 and a circle A2 having a radius r1 that is larger than the reference radius r0 by a distance corresponding to the delay time t1 and centered on the antenna 2
It is determined that the source 12 of the external electromagnetic wave exists at a position corresponding to the intersection with the circle A having the radius r2 that is larger than the radius r1 by the distance corresponding to the delay time t2 with the antenna 14 as the center. In this case, since the reference radius r0 is not measured, only the direction of the source of the external electromagnetic wave is calculated. As shown in FIG. 10, the y3 direction shown in FIG. Specified as a direction.

As described above, according to the present embodiment, extraneous electromagnetic waves are transmitted through the antenna 1, the antenna 2, and the antenna 14,
Received with delays of t1 and t2, respectively.
The received signal is frequency-analyzed by the frequency analyzer 7, and when it is determined by the comparison / determination unit 8 that a predetermined frequency component set in advance exceeds a prescribed allowable level, the CPU 9 stores the received signal in the memory 5. Based on the delay time difference between the received signal of the antenna 1 recorded and stored in the memory 6, the received signal of the antenna 2 recorded and stored in the memory 6, and the received signal of the antenna 14 recorded and stored in the memory 16. Since the direction of the transmission source of the electronic device is specified in one direction, it is possible to accurately specify the transmission direction of the noise that causes a failure in the electronic device and remove the failure.

[Fifth Embodiment] A fifth embodiment of the present invention will be described with reference to FIG. FIG. 11 is a block diagram showing the configuration of the present embodiment.

In the present embodiment, as shown in FIG.
As compared with the first embodiment already described with reference to FIG. 1, an antenna coefficient corrector 23 for correcting a change in phase characteristics due to the frequency of the antennas 1 and 2 is connected to the CPU 9. .

The structure of the other parts of the present embodiment is the same as that of the first embodiment already described, and will not be described again.

The operation of this embodiment having such a configuration will be described. In the present embodiment, the external electromagnetic wave is transmitted through the antenna 1,
At 2, the light is incident with a delay difference of a predetermined time t1, and the first
In the same manner as in the first embodiment, the received signals subjected to AD conversion by the digitizers 3 and 4 are recorded and stored in the memories 5 and 6. Next, the external electromagnetic wave data read from the memory 5 is frequency-analyzed by the frequency analyzer 7 in accordance with a command from the CPU 9, and a predetermined component of the frequency-analyzed external electromagnetic wave data is determined by the comparator 8. A comparison is made to determine whether the level exceeds a preset allowable level. If the level exceeds the allowable level, a noise detection signal is input to the CPU 9 from the comparison / determination unit 8.

The CPU 9 fetches the noise occurrence time from the timer 10 based on the detection signal, and receives the external electromagnetic wave data recorded and stored in the memory 5 and the memory 6.
Calculates the direction of the source of the extraneous electromagnetic wave which is a noise based on the time difference from the extraneous electromagnetic wave data recorded and stored in the memory. In this case, in this embodiment, the data analyzed by the frequency analyzer 7 And antenna coefficient corrector 2
The direction of the source of the external electromagnetic wave is specified in one of the two directions while the variation of the phase characteristic due to the frequency of the antennas 1 and 2 is corrected by the inverse Fourier transform by multiplying by the antenna calibration coefficient from No. 3.

As described above, according to the present embodiment, a foreign electromagnetic wave is received by the antenna 1 and the antenna 2 with a delay of the delay time t1, and the received signal is frequency-analyzed by the frequency analyzer 7 and set in advance. When it is determined by the comparison / determination unit 8 that the predetermined frequency component has been received beyond the prescribed allowable level, the CPU 9 adds the data subjected to the frequency analysis by the frequency analyzer 7 to the data from the antenna coefficient corrector 23. The received signal of the antenna 1 stored in the memory 5 and the received signal stored in the memory 6 are multiplied by the antenna calibration coefficient, and the received signal of the antenna 1 stored in the memory 5 is corrected by the inverse Fourier transform in a state where the phase characteristic variation due to the frequency of the antennas 1 and 2 is corrected. Since the direction of the source of the external electromagnetic wave is specified in one of two directions based on the delay time difference from the received signal of the antenna 2, the The outbound noise harm, to identify with high accuracy without being affected by the frequency, it is possible to remove the fault.

[Sixth Embodiment] A sixth embodiment of the present invention will be described with reference to FIG. FIG. 12 is a block diagram showing the configuration of the present embodiment.

In the present embodiment, as shown in FIG.
In the configuration of the first embodiment, which has already been described with reference to FIG. 1, a spectrum pattern memory 24 for storing a spectrum pattern is connected to the frequency analyzer 7. The configuration of other parts of the present embodiment is as follows.
Since it is the same as that of the first embodiment already described, the description will not be repeated.

The operation of this embodiment having such a configuration will be described. In the present embodiment, an extraneous electromagnetic wave is incident on the antennas 1 and 2 with a delay difference of a predetermined time t1, and the received signals that have been AD-converted by the digitizers 3 and 4 respectively are similar to the first embodiment. Are stored in the memory 5 and the memory 6. Next, according to a command from the CPU 9,
The external electromagnetic wave data read from the memory 5 is frequency-analyzed by the frequency analyzer 7, and a predetermined frequency component of the frequency-analyzed external electromagnetic wave data is
The comparison / determination unit 8 determines whether or not the level exceeds a preset allowable level. If the level exceeds the allowable level, a noise detection signal is input from the comparison / determination unit 8 to the CPU 9.

The CPU 9 fetches the time of occurrence of noise from the timer 10 based on the detection signal, and receives the external electromagnetic wave data recorded and stored in the memory 5 and the memory 6.
Is calculated based on the time difference from the external electromagnetic wave data recorded and stored in the external electromagnetic wave data, and the direction of the external electromagnetic wave source as the noise is specified in one of two directions. In this case, in the present embodiment, the spectrum pattern analyzed by the frequency analyzer 7 is recorded and stored in the spectrum pattern memory 24.

As described above, according to the present embodiment, a foreign electromagnetic wave is received by the antenna 1 and the antenna 2 with a delay of the delay time t1, and the received signal is frequency-analyzed by the frequency analyzer 7 and set in advance. When the comparison / determination unit 8 determines that the predetermined frequency component has been received beyond the prescribed allowable level, the CPU 9 causes the memory 5 to receive the predetermined frequency component.
Based on the delay time difference between the reception signal of the antenna 1 recorded and stored in the memory 6 and the reception signal of the antenna 2 recorded and stored in the memory 6, the direction of the source of the external electromagnetic wave is determined by the CPU 9 in one of two directions. Since the spectrum pattern of the external electromagnetic wave is stored in the spectrum pattern memory 24 at the same time, the transmission direction of the noise that causes a failure in the electronic device is specified in two directions, and at the same time, the spectrum pattern is grasped, and The removal can be performed appropriately.

[0049]

According to the first aspect of the present invention, an external electromagnetic wave is received by the first antenna, and further received by the second antenna with a predetermined time delay from the first antenna. The extraneous electromagnetic wave received by the antenna is recorded and stored in the first storage means, and the extraneous electromagnetic wave received by the second antenna is recorded and stored in the second storage means. The extraneous electromagnetic wave is frequency-analyzed by the frequency analysis means, and is determined by the determination means. It is determined whether a predetermined frequency component of the frequency-analyzed electromagnetic wave has exceeded a preset allowable level. If it is determined that the predetermined frequency component has exceeded the allowable level, the first storage means And the transmission direction of the external electromagnetic wave is calculated based on the time delay of the external electromagnetic wave stored in the second storage means. It is possible to identify the direction to one of two directions.

According to the second aspect of the invention, the external electromagnetic wave is received by the first antenna, and the first electromagnetic wave is received by the second antenna.
Is received with a delay of a first predetermined time with respect to the antenna of the second antenna, and is received by the third antenna with a delay of a second predetermined time with respect to the second antenna, and the extraneous electromagnetic wave received by the first antenna is The external electromagnetic wave received by the second antenna is stored in the first storage means, the external electromagnetic wave received by the third antenna is stored in the third storage means, and the external electromagnetic wave is stored in the third storage means. The frequency analysis is performed by the means, the determination means determines whether or not the predetermined frequency component of the frequency-analyzed electromagnetic wave exceeds a preset allowable level, and when the predetermined frequency component is determined to have exceeded the allowable level, The transmitting direction of the external electromagnetic wave is calculated by the calculating unit based on the time delay of the external electromagnetic wave stored in the first storing unit, the second storing unit, and the third storing unit. In, it is possible to identify the direction of the source of external electromagnetic waves in one direction in all directions.

According to the third aspect of the present invention, in addition to the effect obtained by the first or second aspect of the present invention, the time at which an extraneous electromagnetic wave exceeding an allowable level is generated can be measured by the time measuring means. Will be possible.

According to the fourth aspect of the present invention, in addition to the effect obtained by the first aspect of the present invention, in addition to the effect obtained by the first antenna and the second antenna, the shielding means provided over the second antenna can reduce the external electromagnetic wave. Since incidence on the first antenna and the second antenna from one predetermined direction is shielded,
In the direction of the predetermined range, the direction of the source of the external electromagnetic wave can be specified in one direction.

According to the fifth aspect of the present invention, in addition to the effects obtained by the first or second aspect of the present invention, the first aspect
Since the electromagnetic wave absorber is provided near at least one of the first antenna and the second antenna, or at least one of the first antenna, the second antenna, and the third antenna, an adverse effect due to the reflection of the electromagnetic wave is provided. Can be prevented.

According to the sixth aspect of the present invention, in addition to the effects obtained by the first or second aspect of the present invention, the first antenna, the second antenna, and the third antenna are corrected by the antenna coefficient correcting means. The antenna coefficient for correcting the phase variation due to the frequency of the antenna is corrected and set, the frequency-analyzed data is multiplied by the antenna coefficient, and the extraneous electromagnetic wave in the time domain is calculated by the inverse Fourier transform. It is possible to specify the direction of the source of the external electromagnetic wave with high accuracy in consideration of the variation in the characteristics.

According to the seventh aspect of the present invention, in addition to the effects obtained by the first or second aspect of the present invention, the result calculated by the arithmetic means is stored as a spectrum pattern by the storage means. It is possible to accurately measure the spectrum pattern of the external electromagnetic wave.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a waveform of an external electromagnetic wave received in the embodiment.

FIG. 3 is a diagram illustrating the principle of calculation of the direction of emission of an external electromagnetic wave in the embodiment.

FIG. 4 is a block diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a configuration of a main part of the embodiment.

FIG. 6 is an explanatory diagram showing an electromagnetic wave shielding operation of the embodiment.

FIG. 7 is a block diagram showing a configuration of a third exemplary embodiment of the present invention.

FIG. 8 is an explanatory diagram showing an operation of the embodiment.

FIG. 9 is a block diagram showing a configuration of a fourth exemplary embodiment of the present invention.

FIG. 10 is a diagram illustrating the principle of calculation of the direction of transmission of an external electromagnetic wave according to the embodiment.

FIG. 11 is a block diagram showing a configuration of a fifth exemplary embodiment of the present invention.

FIG. 12 is a block diagram illustrating a configuration of a sixth exemplary embodiment of the present invention.

[Explanation of symbols]

 1, 2, 14 Antenna 3, 4, 15 Digitizer 5, 6, 16 Memory 7 Frequency analyzer 8 Comparison / determination unit 9 CPU 10 Timer 11 Electromagnetic wave shielding plate 12, 13 Source 17 Radio wave absorber 19 Electromagnetic wave reflector 20 Electromagnetic wave 22 reflected electromagnetic wave 23 antenna coefficient corrector 24 spectrum pattern memory

Claims (7)

[Claims] 1. A first antenna for receiving an external electromagnetic wave, a first storage unit for recording and storing the external electromagnetic wave received by the first antenna, and a method for storing the external electromagnetic wave for a predetermined time longer than the first antenna A second antenna that receives the delayed electromagnetic wave; a second storage unit that records and stores the external electromagnetic wave received by the second antenna; a frequency analyzing unit that analyzes the frequency of the external electromagnetic wave; Determining means for determining whether the analyzed predetermined frequency component of the electromagnetic wave has exceeded a preset allowable level; and the determining means determines that the predetermined frequency component of the foreign electromagnetic wave has exceeded the allowable level. Then, the first
And a calculating means for calculating a transmitting direction of the external electromagnetic wave based on a time delay of the external electromagnetic wave stored in the second storing means. 2. A first antenna for receiving an external electromagnetic wave, first storage means for recording and storing the external electromagnetic wave received by the first antenna, and a first storage means for storing the external electromagnetic wave at a first position higher than that of the first antenna. A second antenna for receiving the external electromagnetic wave received by the second antenna, recording and storing the external electromagnetic wave received by the second antenna; and a second predetermined unit for storing the external electromagnetic wave at a second predetermined distance from the second antenna. A third antenna that receives with a time delay, a third storage unit that records and stores the external electromagnetic wave received by the third antenna, a frequency analysis unit that performs frequency analysis on the external electromagnetic wave, and the frequency analysis unit Determining means for determining whether or not a predetermined frequency component of the frequency-analyzed electromagnetic wave exceeds a preset allowable level; If it is determined that exceeds the bell, the first
Storage means, and a calculation means for calculating the transmission direction of the foreign electromagnetic wave based on the time delay of the foreign electromagnetic wave stored in the second storage means and the third storage means. EMI measurement equipment. 3. The electromagnetic interference wave measuring apparatus according to claim 1, further comprising: a time measuring means for measuring a time when the external electromagnetic wave exceeds the allowable level. Electromagnetic interference wave measurement device. 4. The electromagnetic interference measuring apparatus according to claim 1, wherein shielding means for shielding the external electromagnetic wave from entering the first antenna and the second antenna from a predetermined direction is provided. An electromagnetic interference wave measuring device, which is disposed over the first antenna and the second antenna. 5. The electromagnetic interference wave measuring device according to claim 1, wherein at least one of the first antenna and the second antenna, or the first antenna and the second antenna. An electromagnetic interference wave measuring device, wherein an electromagnetic wave absorber that absorbs an external electromagnetic wave is disposed near at least one of the antenna and the third antenna. 6. The electromagnetic interference wave measuring apparatus according to claim 1, wherein the first antenna, the second antenna, and the third antenna.
An antenna coefficient correcting means for correcting a phase variation due to the frequency of the antenna. 7. The electromagnetic interference measuring apparatus according to claim 1, further comprising: a storage unit that stores a result calculated by the calculation unit as a spectrum pattern. Interference wave measurement device.