JPH06324098A - Electromagnetic-interference-wave measuring instrument - Google Patents

Abstract

PURPOSE:To provide the electromagnetic-interference-wave measuring instrument, which can automatically record the electromagnetic-interference wave having the frequency component exceeding the preset level in an arbitrarily set frequency band and can estimate and specify the transmitting sources. CONSTITUTION:The waveform of a level exceeding the distribution of the frequency spectrum, which can be preset based on the fluctuation level of ordinary frequency-spectrum distribution, is detected by using a level judging part. At this time, the data, which are measured with a frequency-spectrum measuring part 8, are stored in a memory-means part 10 together with the detected time information with a control part 9. Thus, the comparison with the generated time of the electromagnetic interference can be performed. The specification of the frequency component of the electromagnetic wave and the estimation and specification of the generating source of the electromagnetic-interference wave can be carried out. Furthermore, the frequency-spectrum measuring part 8 and the control part 9 thereof are made to form a unitary body. A temporary memory part is provided in the frequency-spectrum measuring part 8. Thus, the measurement is made efficient.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring instrument for detecting a frequency spectrum at a time point when a waveform exceeding the normally observed frequency spectrum distribution intensity is input in a preset frequency range, and it is an obstacle to an electronic device. The present invention relates to an electromagnetic interference wave measuring instrument that can be used for measurement of an electromagnetic interference wave that is a cause.

[0002]

2. Description of the Related Art In recent years, electromagnetic pulses caused by a natural phenomenon such as lightning, radio waves from amateur radio, CB radio, radio broadcasting and the like have been a cause of malfunction such as malfunction of electronic devices.
This kind of problem is spurred by the decline in the resistance of electronic devices to electromagnetic interference caused by higher speeds and lower power consumption of semiconductor devices, and the deterioration of the electromagnetic environment due to the significant increase in electronic devices that cause electromagnetic interference. I am putting on. However, an electromagnetic interference wave that causes a failure of an electronic device is generated by various mechanisms, and its temporal distribution and intensity are also uncertain, and reproducibility is often poor. Furthermore, electromagnetic interference waves are often transient, and it is difficult to identify the cause of the interference.

When an electromagnetic interference occurs in an area where there are a plurality of wireless transmission facilities, it is necessary to investigate whether the cause of the interference is an electromagnetic wave from a nearby transmitting station or another electromagnetic wave. There is. For such a purpose, fluctuations in the electric field strength were monitored in advance on the frequency axis for mobile radio stations, etc. that may have passed the radio transmission broadcasting station or its vicinity, which can be assumed to have caused a problem, and actually occurred. One of the methods of estimating the cause of failure is to compare it with the time of occurrence of electromagnetic interference.
In other words, by monitoring the time of occurrence of an actual fault and the fluctuation range of the electric field strength at that time on the frequency axis, it is possible to estimate and identify the frequency component of the electromagnetic wave that caused the fault and the transmission source. It will be possible.

For the purpose of detecting an electromagnetic interference wave which may cause an electromagnetic interference, there is a conventional method of using a spectrum analyzer. In this case, a method of constantly setting the spectrum analyzer to the measurement state and transferring the measurement data to the external memory regardless of the occurrence of a failure in the electronic device can be considered. A conventional example of this method is shown in FIG. In FIG. 8, 1 is a receiving antenna,
Reference numeral 2 is a spectrum analyzer, 3 is a control device, 4 is a radiating antenna, and 5 is an electronic device having an output terminal for a fault detection signal. Here, consider a situation in which an electromagnetic wave having a waveform of a certain level or higher is measured by the spectrum analyzer 2 when an electromagnetic wave whose amplitude component or the like fluctuates irregularly with time is emitted from the radiation antenna 4. The spectrum analyzer 2 is constantly in the measurement state and transfers the measurement data to the control device 3. When a failure occurs in the electronic device 5, a failure detection signal is output to the control device 3, and it becomes possible to compare the occurrence of electromagnetic interference with the waveform fluctuation.

[0005]

However, the conventional electromagnetic interference wave measuring technique having the configuration of FIG. 8 has the following problems. Under the setting of FIG. 8, if it is intended to detect the presence or absence of a waveform of the frequency spectrum of the electromagnetic wave radiated from the radiating antenna 4 that is always higher than the radiating level, on the frequency axis in the spectrum analyzer 2. It is necessary to transfer the measurement data to the control device 3 and to determine the level of the emission radar each time the sweep is performed once. At that time, while transferring the measurement data from the spectrum analyzer 2 to the control device 3, the inside of the control device 3 determines the level of the measurement data (comparison with the array information recorded as the reference level) for several tens of meters or more. Spectrum analyzer 2
In addition, it takes several seconds or more between the series of processes until the remeasurement start command is completed. During that time, the spectrum analyzer 2 becomes incapable of measurement, and there is a problem that it cannot be said to be necessarily efficient for the measurement for the purpose of continuously monitoring the electromagnetic environment for a long time. In addition, the process of determining the level of the target frequency spectrum must be performed on a program in the control device 3, and a part of the program is changed every time when the frequency range for trigger or the trigger level is changed. There was a problem that functional inconvenience such as the need to rewrite occurred.

As described above, according to the above conventional technique,
In the electromagnetic environment where a steady or quasi-stationary waveform is radiated irregularly, the measurement unit and the processing unit of the measurement data are used for the purpose of monitoring the frequency spectrum fluctuation status and the occurrence of the frequency spectrum over a long period of time. It is important that they are integrated in order to reduce the processing time. In addition, if the program in the external control device connected to the measuring device performs the processing to detect the presence or absence of the frequency spectrum that exceeds the arbitrary setting level in the arbitrary frequency range, the frequency range for triggering and the trigger Whenever you change levels,
It causes inconvenience such as rewriting a part of the program.

Therefore, it is possible to continuously sweep the frequency spectrum and automatically process the accumulation of the measurement data regarding the frequency spectrum which exceeds the normal fluctuation level or exceeds the normal fluctuation level by a preset ratio. The development of vessels was desired.

The present invention has been made to solve the above-mentioned problems, and its purpose is to automatically record an electromagnetic interference wave having a frequency component higher than a set level in an arbitrarily designated frequency band and to generate its source. An object of the present invention is to provide an electromagnetic interference wave measuring device capable of estimating and identifying

[0009]

In order to achieve the above-mentioned object, an electromagnetic interference measuring instrument according to the present invention comprises a measuring section for extracting a frequency spectrum of an arbitrary frequency band from a time waveform sent from an input section, Temporary storage unit of the frequency spectrum swept in the measurement unit, determination of whether or not a frequency spectrum equal to or more than the trigger frequency spectrum distribution determined from the frequency spectrum average distribution after a plurality of sweeps in the measurement unit is input to the measurement unit A frequency spectrum determination unit configured by a frequency level determination unit,
Based on a control unit for controlling the frequency spectrum measuring unit and a control signal from the control unit, the time waveform input to the input unit and sent thereto satisfies the condition of being equal to or higher than the level of the trigger frequency spectrum distribution. And a storage unit that stores the frequency spectrum transferred from the temporary storage unit of the frequency spectrum measurement unit together with the detection time information.

[0010]

According to the present invention, in the preset frequency band, the frequency level determination unit determines a waveform having a level exceeding the settable trigger frequency spectrum distribution from the fluctuation level of the normal frequency spectrum in which no electromagnetic interference problem occurs. By detecting and storing the detection time information together with the measurement data of the frequency spectrum measurement unit in the storage means by the control unit, the frequency component above the level of the trigger frequency spectrum distribution set in any specified frequency band is detected. In addition to enabling automatic storage of the electromagnetic waves that it possesses along with detection time information, it also enables comparison with the time of occurrence of electromagnetic interference, identifying the frequency components of the electromagnetic interference that caused the interference, and estimating the source of the electromagnetic interference. Allows identification. In addition, the frequency spectrum measurement unit and its control unit are integrated,
Moreover, by providing the frequency spectrum measuring unit with a temporary storage unit, the processing time is shortened and the measurement efficiency is improved.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the structure of an electromagnetic interference wave measuring instrument according to the first embodiment of the present invention. In FIG. 1, 6 is an electromagnetic interference wave measuring device, 7 is an input part of the electromagnetic interference wave measuring device 6, 8 is a frequency spectrum measuring part of the electromagnetic interference wave measuring device 6, 9 is a control part of the electromagnetic interference wave measuring device 6, Reference numeral 10 is a storage unit of the electromagnetic interference wave measuring device 6, and 11 is an electromagnetic interference wave measuring device 6.
Fault detection receivers, 12-1, 12-2 are modems, 13
Is a remote control device for the electromagnetic interference wave measuring device 6.

First, a time waveform such as an electromagnetic interference wave propagating in space is continuously sent from the input section 7 to the measuring section 8.
At this time, the frequency spectrum measuring unit 8 has a function of extracting the frequency spectrum, and has a frequency spectrum distribution level measured in advance or a frequency spectrum distribution (trigger that exceeds an arbitrary set ratio from the normal frequency spectrum distribution level). If the electric field strength is higher than the frequency spectrum distribution level for use,
The measurement data is transferred to the storage unit 10 based on the control command from the control unit 9, and is accumulated together with the detection time. When the trigger judgment frequency range includes an electric field strength equal to or higher than the trigger frequency spectrum distribution level, the sweep is repeated a predetermined number of times and the maximum value of the frequency spectrum is held for a certain period of time. Can be set to be transferred from the frequency spectrum measuring unit 8 to the storage unit 10.

The control unit 9 has a function of controlling the frequency spectrum measuring unit 8 and, when the failure detection receiving unit 11 receives the failure detection signal, recording the time together with the storage unit 10. It is also possible to set the frequency spectrum measurement unit 8 to output a measurement start command when a failure detection signal is received. The storage unit 10 can be a non-volatile memory such as an FDD, a hard disk, or a magneto-optical disk.

Further, by using the modems 12-1 and 12-2, a control command from the remote control device 13 interrupts the electromagnetic interference wave measuring device 6 via the telephone line,
It is possible to change the sweep frequency range, measurement voltage level, trigger judgment frequency range, and transfer and delete measurement data.

Thus, it becomes possible to measure the fluctuation status of the frequency spectrum of the detected time waveform while comparing it with the presence or absence of the occurrence of the fault detection signal.

FIG. 2 is a diagram for explaining the measuring method of the frequency spectrum measuring unit 8 of this embodiment. In FIG. 2, the horizontal width is the frequency axis, the vertical axis is the sensitivity or reception level of the frequency spectrum, and fo to fn are the frequency measuring units 8.
Indicates the frequency band measured in.

In the following, it is assumed that electromagnetic waves due to CB radio or the like are suddenly and strongly radiated. When a communication device or the like malfunctions, it is an effective method to determine the cause of the failure by measuring the level fluctuation of the electromagnetic wave that can cause the failure on the frequency axis and comparing it with the occurrence of the failure. Here, the frequency spectrum average distribution level (solid line) at the time when the problem of electromagnetic interference does not occur is measured and stored in advance,
A frequency spectrum distribution of a level exceeding x% from the fluctuation level of the solid line is set as a trigger frequency spectrum distribution level (dotted line).

Under this setting, the frequency bands fo to fn
When a frequency spectrum with an intensity equal to or higher than the trigger frequency spectrum distribution level is captured, it means that a waveform of a level that is not normally observed is input in this band range. Further, if an electromagnetic interference occurs under this set condition and the measured waveform is not stored in the storage means unit 10, it means that an electromagnetic wave having a frequency component other than fo to fn is the cause. Moreover, the value of the trigger level of the frequency spectrum can be arbitrarily changed by changing the value of x. Furthermore, it is possible to use a method in which the activation is performed by changing the level only in the designated frequency range.

By using the method shown here, it is possible to observe the fluctuation of the frequency spectrum in an arbitrary frequency range, and there is an advantage that it leads to the investigation of the transmission source of the electromagnetic wave causing the electromagnetic interference. To be

FIG. 3 is a block diagram showing a basic circuit configuration example of the frequency spectrum measuring unit 8 of the present invention. In FIG. 3, as elements constituting the frequency spectrum measuring unit 14, 14 is an attenuator, 15 is a low-pass filter, 16 is a first mixer, 17 is a first local oscillator, 18 is a first intermediate frequency amplifier, 19 Is a sweep oscillator, 20 is a second mixer, 21 is a second mixer
A local oscillator, 22 is a second intermediate frequency amplifier, 23 is a horizontal axis amplifier, 24 is a logarithmic amplifier, 25 is a detector, 26 is a video amplifier, 27 is a CRT, 28 is a frequency controller of the sweep oscillator 19, and 29 is A measurement unit, 30 is a spectrum temporary storage unit, 31 is a level determination unit, 32 is a frequency spectrum average level storage unit, and 33 is a detected waveform trigger processing unit.
The input unit 7 shown in FIG. 1 is the attenuator 14, and the control unit 9 is the measurement unit 29, the spectrum temporary storage unit 30, and the level determination unit 31.
, Respectively.

The sweep oscillator 19 generates a sawtooth voltage waveform, and this voltage causes the first local oscillator 17 and the second local oscillator 17 to generate a voltage waveform.
The oscillation frequency of the station oscillator 21 is swept, this voltage is applied from the horizontal axis amplifier 23 to the horizontal polarization plate of the CRT 27, and the horizontal axis is swept in proportion to the frequency. The frequency range to be swept is set by the frequency control unit 28 by setting the target frequency of the sweep oscillator 19. Input section 7
The waveform input to the attenuator 14 from the low-pass filter 15
Then, the output from the sweep oscillator 19 is added via the first local oscillator 17 for each target frequency in the first mixer 16. Then, it is amplified by the first intermediate frequency 18, and the output of the second local oscillator 21 is mixed by the second mixer 20,
Second intermediate frequency amplifier 22, logarithmic amplifier 24, detector 2
The output voltage after 5 is applied to the CRT 27 from the spectrum temporary storage unit 30 and the video amplifier 26. At this time, in the measuring unit 29, it is possible to take out the frequency spectrum average distribution under a normal electromagnetic environment by repeating the sweeping any number of times in a state where no electromagnetic interference has occurred, and the measured frequency can be obtained. It is possible to temporarily store the spectrum information in the frequency spectrum average level storage unit 32. In the above configuration, the frequency spectrum measuring unit 8 includes the CRT 27, the measuring unit 29,
The detection waveform trigger processing unit 33 is roughly classified.

The processing method of the detected waveform trigger processing unit 33 for determining the trigger condition of the waveform detected by the measuring unit 29 will be described below.

In FIG. 3, the frequency control unit 28 measures an arbitrary frequency region, and the measurement data is repeatedly output to the spectrum temporary storage unit 30. The level determination unit 31 uses the frequency spectrum average level storage unit 3 within the set frequency range.
When the measured data having a value larger than the value (x%) arbitrarily set with respect to the frequency spectrum level stored in 2 is output to the spectrum temporary storage unit 30, the control signal of the control unit 9 is set. Based on this, it has a function of transferring the measurement data to the storage unit 10. As a result, when the frequency component of the time waveform to the input unit 7 includes the electric field strength having a level higher than an arbitrary ratio from the normal frequency spectrum distribution level in the frequency range designated in advance, It becomes possible to detect it. There is also a method of setting the data to be transferred to the storage unit 10 regardless of the level of the measurement data held in the spectrum temporary storage unit 30.

By taking the circuit configuration as described above,
The advantage is that the fluctuation level of the waveform can be automatically monitored on the specified frequency axis.

FIG. 4 is a block diagram showing a configuration example of an electromagnetic interference wave measuring device according to the second embodiment of the present invention. In FIG. 4, 34 is a frequency spectrum average level correction value storage unit, and the other elements from 7 to 31 are the same as those in the first embodiment of FIG. In the present embodiment, a frequency spectrum average level correction value storage unit 34 is connected instead of the frequency spectrum average level storage unit 32 of FIG.

In the embodiment shown in FIG. 4, the frequency spectrum distribution in the fixed state detected by the measuring unit 29 is not temporarily stored as it is for trigger measurement but is temporarily stored as a correction value. As a correction method, envelope detection of the detected frequency spectrum average level, spline complementation, or the like can be used. Also according to this embodiment, the same operation as that of the first embodiment can be performed and the same effect can be obtained.

FIG. 5 is a diagram showing an application example of the electromagnetic interference wave measuring device of the present invention. In FIG. 5, 1 is a receiving antenna, 4
-1, 4-2, 4-3 are radiating antennas of broadcasting stations A, B, C, 5 is an electronic device having a failure detection signal output section, 6
Is an electromagnetic interference wave measuring device of the present invention, and 35 is a radiation antenna of the mobile radio station D.

Hereinafter, a plurality of radio wave transmitting stations (broadcasting transmitting stations A,
Assume a measurement aimed at investigating the electromagnetic environment in an area where B, C) are mixed. When the electronic device 5 fails irregularly, it is an effective method to observe the frequency level fluctuation for each frequency band of the CB radio that may pass through the transmitting station near the electronic device installation location or the vicinity. ,
Here, the trigger level is set and monitored for each frequency of the mobile radio stations D passing through the broadcast transmitting stations A, B, C and the vicinity.

The electromagnetic interference wave propagating in the space is continuously sent to the frequency spectrum measuring section 8 of the electromagnetic interference wave measuring instrument 6 via the receiving antenna 1, and the frequency component is taken out.
Now, the antennas 4-of the mobile radio station D that may pass through the broadcasting stations A, B, C to be detected and the vicinity 4-
The frequencies of the electromagnetic waves radiated from 1, 4-2, 4-3, and 35 are fA, fB, fC, and fD, respectively, and the frequency points normally detected by the receiving antenna 1 are always present (electromagnetic interference does not occur). Electric field level (at time point) EA, EB, EC,
Let ED.

At this time, the normal frequency fluctuation level (solid line)
6 shows an example (dotted line) of the electromagnetic environment detected at the time when the electromagnetic interference occurs in the electronic device 5 with the trigger frequency spectrum distribution level set to 10% above the constant fluctuation level. Is. From FIG. 6, it is possible to estimate that the electric field strength at the point of the frequency fD fluctuates greatly at the time when the failure occurs in the electronic device 5, and the electromagnetic interference that occurred is due to the mobile radio station D. I was able to verify that.

FIG. 7 is a block diagram showing a basic configuration example of an electromagnetic interference wave measuring instrument showing a third embodiment of the present invention. Figure 7
In FIG. 7, 7'is an input unit, 36 is a time waveform measuring unit, and the other elements 7 to 10 are the same as those in the first embodiment.

In the present embodiment, when a waveform having a level higher than a preset level is input from the input unit 7'to the time waveform measuring unit 36, the time waveform measuring unit is stored in the storage unit 10 based on the control signal of the control unit 9. The detection data of 36 is set to be accumulated, which has the effect that not only the frequency component of the electromagnetic interference wave but also the time waveform can be stored, and the cause of the electromagnetic interference can be further clarified. .

[0034]

As described above, the electromagnetic interference wave measuring instrument according to the present invention can detect an electromagnetic wave having a frequency component equal to or higher than the set trigger frequency spectrum distribution level within an arbitrarily designated frequency band. Since it has a function of automatically storing it together with the detection time, it is possible to estimate / identify the frequency characteristics (electric field strength, etc.) of the electromagnetic wave and the transmission source that cause the interference by comparing with the occurrence of the electromagnetic interference. Further, it is possible to measure the time variation of the electric field strength in the frequency domain regardless of the occurrence of electromagnetic interference, and it is possible to obtain the effect that it can be applied to the investigation of the electromagnetic environment. Furthermore, since the invention of claim 2 has the function of storing the time waveform in addition to the above, it is possible to obtain the effect of further facilitating the estimation and identification of the transmission source that has caused the electromagnetic interference.

The measurement of the electromagnetic environment using the electromagnetic interference wave measuring device of the present invention leads to the elucidation of the cause of failure of the electronic device due to the electromagnetic interference wave and the establishment of countermeasure technology against the electromagnetic interference, and the effect thereof is extremely high. large.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an electromagnetic interference wave measuring device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a measuring method of a frequency spectrum measuring unit according to the first embodiment.

FIG. 3 is a block diagram showing a basic circuit configuration example of a frequency spectrum measuring unit of the electromagnetic interference wave measuring device according to the first embodiment.

FIG. 4 is a block diagram showing a basic circuit configuration example of a frequency spectrum measuring unit of an electromagnetic interference wave measuring instrument according to a second embodiment of the present invention.

FIG. 5 is a diagram showing an application example of the electromagnetic interference wave measuring device of the present invention.

6 is a diagram showing an example of a detected waveform obtained under the setting of FIG.

FIG. 7 is a block diagram showing a basic configuration example of an electromagnetic interference wave measuring device according to a third embodiment of the present invention.

FIG. 8 is a diagram showing a conventional example of measuring an electromagnetic interference wave by combining a conventional spectrum analyzer and a control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Receiving antenna 4-1, 4-2, 4-3 ... Radiating antenna 5 ... Electronic device which has a failure detection signal output part 6 ... Electromagnetic interference wave measuring device 7 ... Input part of electromagnetic interference wave measuring device 8 ... Electromagnetic Frequency spectrum measuring unit 9 of the electromagnetic interference wave measuring device 9 ... Control unit of the electromagnetic interference wave measuring device 6 ... Storage means unit 11 of the electromagnetic interference wave measuring device 11 ... Failure detection receiving unit 12-1 of the electromagnetic interference wave measuring device 6 12-2 ... Modem 13 ... Remote control device for electromagnetic interference wave measuring instrument 14 ... Attenuator 15 ... Low-pass filter 16 ... First mixer 17 ... First local oscillator 18 ... First intermediate frequency amplifier 19 ... Sweep transmission 20. Second mixer 21 ... Second local oscillator 22 ... Second intermediate frequency amplifier 23 ... Horizontal axis amplifier 24 ... Logarithmic amplifier 25 ... Wave detector 26 ... Video amplifier 27 ... CRT 28 ... Frequency control unit 29 ... Measuring unit 30 ... Temporary spectrum憶部 31 ... level determining unit 32 ... frequency spectrum average level storage unit 33 ... detected waveform trigger processor 34 ... frequency spectrum average level correction value storage unit 35 ... radiating antenna 36 ... time waveform measurement unit of the mobile radio station

Claims (2)

[Claims] 1. A measuring unit for extracting a frequency spectrum of an arbitrary frequency band from a time waveform sent from an input unit,
A temporary storage unit for the frequency spectrum swept in the measurement unit, whether or not a frequency spectrum of a trigger frequency spectrum distribution determined from the frequency spectrum average distribution after a plurality of sweeps in the measurement unit is input to the measurement unit A frequency spectrum measurement unit configured by a frequency level determination unit that performs determination, a control unit that controls the frequency spectrum measurement unit, and a signal that is input to the input unit and transmitted based on a control signal from the control unit. A storage unit that stores the frequency spectrum transferred from the temporary storage unit of the frequency spectrum measurement unit together with detection time information when it is determined that the incoming time waveform satisfies the level of the trigger frequency spectrum distribution or higher. An electromagnetic interference wave measuring instrument comprising: 2. The electromagnetic interference wave measuring device according to claim 1, further comprising: a time waveform measuring unit that detects a time waveform when a waveform having a level set to an arbitrary level or higher is input, and is based on a control signal from the control unit. An electromagnetic interference wave measuring instrument characterized by storing the detected time waveform in a storage means.