JPH06258366A - Electromagnetic interference wave measuring device - Google Patents

Abstract

PURPOSE:To enable easy identification of electromagnetic interference wave, in an electromagnetic interference wave measuring device, by automatically processing detection and accumulation of electromagnetic wave of arbitrary frequency range and setting level. CONSTITUTION:At a frequency spectral measuring part 8, a measuring part 29 and a spectral temporary storage part 30 sweep the preset frequency band for taking out frequency spectral, and a level decision part 31 detects the spectral waveform of the level, equal to the arbitrary set trigger level or above, in the trigger decision frequency range set arbitrary. Then, the measured data of time detected waveform is, together with detection time information, accumulated in a non-volatile memory part 10, so that detection time of measured data and occurrence time of electromagnetic fault may be compared with each other, for facilitating specification of frequency component of electromagnetic interference wave that caused obstruction trouble and assumption/specification of an originator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring device for detecting a frequency spectrum at the time of input of a waveform having an intensity which is arbitrarily set within a preset frequency range, and causes a trouble of an electronic device. The present invention relates to an electromagnetic interference wave measuring device used for measuring electromagnetic interference waves.

[0002]

2. Description of the Related Art In recent years, electromagnetic pulses caused by lightning discharge, electrostatic discharge, TV broadcast waves, amateur radio, CB radio,
Radio waves caused by radio broadcasting and the like cause troubles 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 electromagnetic interference frequently 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 electromagnetic waves from a nearby transmitting station or completely other electromagnetic waves. There is. For such a purpose, for the mobile radio station that may have passed through the radio transmission broadcasting station or its vicinity, which can be considered to be a problem, the fluctuation of the electric field strength is monitored in advance on each frequency axis, and the actual One of the methods of estimating the cause of a failure is to compare it with the time of occurrence of the electromagnetic interference that has occurred. 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 electromagnetic interference waves that may cause electromagnetic interference, there has been a 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. This method will be described below with reference to FIG. 7.

In FIG. 7, 1 is a receiving antenna, 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. When a failure occurs in the electronic device 5, a failure detection signal is output to the control device 3,
It is possible to compare the occurrence of electromagnetic interference with the waveform fluctuation.

[0006]

However, the method of measuring an electromagnetic interference wave according to the conventional configuration of FIG. 7 has the following problems. Under the above settings, when 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 radiation level, the spectrum analyzer 2 moves along the frequency axis. It is necessary to transfer the measurement data to the control device 3 for each sweep to determine the level of the emission radar. At that time, while the measurement data is transferred from the spectrum analyzer 2 to the control device 3, the control device 3 determines the level of the measurement data for several tens of milliseconds or more, and the spectrum analyzer 2
In addition, several hundreds of milliseconds or more are required between the series of processes until the remeasurement start instruction is completed. Meanwhile, the spectrum analyzer 2 cannot be measured. Therefore, there is a problem that the measurement is not always efficient 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.

From the above, in the environment where a steady or quasi-stationary waveform is radiated irregularly, it is necessary to measure the frequency spectrum fluctuations over a long period of time, and to monitor the occurrence or non-occurrence of the frequency spectrum. It is important to reduce the processing time by integrating the unit and the measurement data processing unit. In addition, if the program in the external device connected to the measuring device performs the processing to detect the presence or absence of the frequency spectrum above the set level in the arbitrary frequency range, the frequency range for triggering and the trigger Whenever you change the level, you have to rewrite a part of the program every time. Therefore, a measuring device capable of continuously sweeping the frequency spectrum and automatically processing the accumulation of measurement data when electromagnetic waves such as CB radio or broadcast wave whose frequency can be predicted in advance exceed a certain level. Development was desired.

The present invention has been made to solve the above problems, and an object thereof is to automatically process a process of detecting and accumulating an electromagnetic wave of an arbitrary set level in an arbitrary frequency range, thereby causing a failure. An object of the present invention is to provide an electromagnetic interference wave measuring device that facilitates the identification of the electromagnetic interference wave that has caused the generation.

[0009]

In order to achieve the above object, in an electromagnetic interference wave measuring apparatus of the present invention, a measuring section for extracting a frequency spectrum of an arbitrary frequency band from a time waveform sent from an input section, A temporary storage unit of the frequency spectrum swept by the measuring unit, and whether the frequency spectrum of the trigger determination frequency range arbitrarily specified between the frequency bands on the temporary storage unit is equal to or higher than an arbitrarily set trigger level. Based on a control signal from the frequency spectrum measurement unit, a frequency spectrum measurement unit configured to determine the frequency level determination unit, the frequency spectrum measurement unit, and the control unit, the time waveform input to the input unit. If the condition equal to or higher than the trigger level set in the frequency range for trigger determination of the frequency level determination unit is satisfied, It has a configuration which includes storage means for storing the frequency spectrum to be transferred from the spectrum measuring section with detection time information of the frequency spectrum, the.

[0010]

In the electromagnetic interference wave measuring device of the present invention, in the frequency spectrum measuring section, the measuring section and the temporary storage section sweep the preset frequency band to extract the frequency spectrum, and the frequency range for trigger determination is set arbitrarily. The frequency determination unit detects a spectrum waveform equal to or higher than the trigger level in. Then, by accumulating the measurement data of the detected waveform together with the detection time information,
By making it possible to compare the detection time of the measurement data with the occurrence time of the electromagnetic interference, it is possible to identify the frequency component of the electromagnetic interference wave that is the cause of the interference and to estimate and identify the source of the electromagnetic wave.

[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 arrangement of an electromagnetic interference wave measuring apparatus 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, 10
Is a non-volatile memory unit of the electromagnetic interference wave measuring device 6, 11 is a failure detection receiving unit of the electromagnetic interference wave measuring device 6, 12-1, 12
Reference numeral -2 is a modem, and 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 when the electric field strength equal to or higher than the trigger level is included in the preset trigger determination frequency range, the measured data is controlled. Part 9
Is transferred to the non-volatile memory unit 10 on the basis of the control command from and is stored together with the detection time. If the electric field strength equal to or higher than the trigger level is included in the frequency range for trigger determination, sweeping is repeated a preset number of times, the maximum value of the frequency spectrum is held for a certain period of time, and then the measurement data is measured. It is also possible to set the transfer from the unit 8 to the non-volatile memory unit 10.

The control unit 9 has a function of controlling the frequency spectrum measuring unit 8 and recording the time when the fault detection signal is received by the fault detection receiving unit 11 in the non-volatile memory 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.

Further, by using the modems 12-1 and 12-2 to connect the control unit 9 and the remote control device 13 with a telephone line, an optical fiber, radio or the like, the remote control device 13 is connected.
It is possible to change the settings of the sweep frequency range, measurement voltage level, trigger judgment frequency range, trigger level, and transfer and delete the measurement data by interrupting the control command from the electromagnetic interference wave measuring device 6 or manually. Become.

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 the present invention. In FIG. 2, the horizontal axis is the frequency axis, the vertical axis is the sensitivity or reception level of the frequency spectrum, and f0 to fn are the frequency measurement unit 8
Indicates the frequency band measured in.

In the following, it is assumed that electromagnetic waves from the CB radio or the like that fall within the frequency bands f1 to f2 are rapidly and strongly radiated. When a communication device malfunctions, it is effective to pick up some radio waves that can cause a failure and measure the level fluctuation for each frequency band to compare with the occurrence of the failure. Is the way. Here, when the constant fluctuation level of the frequency spectrum in the frequency bands f1 to f2 is Ea, a value Et above that value is set as the trigger level. Under this setting, when a frequency spectrum having an intensity of Et or higher is captured in the frequency bands f1 to f2, it means that a waveform of a level that is not normally observed is input to this band range. If an electromagnetic interference occurs under these set conditions and the measured waveform is not stored in the non-volatile memory 10, it means that the electromagnetic wave has a frequency component other than f1 to f2.

The value of the trigger level Et of the frequency spectrum can be arbitrarily changed according to the situation, and also with respect to the frequency range for triggering, for example, a plurality of trigger levels Et'are simultaneously set in the frequency range of f3 to f4. A method is also possible. 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.

FIG. 3 is a block diagram showing a basic circuit configuration example of the frequency spectrum measuring section 8 in the first embodiment of FIG. 1 of the present invention. In FIG. 3, 7 to 11 are the portions described in FIG. 1, and as the components of the frequency spectrum measuring unit 14, 14 is an attenuator, 15 is a low-pass filter, 16 is a first mixer, and 17 is A first local oscillator, 18 is a first intermediate frequency amplifier, 19 is a swept oscillator, 20 is a second mixer, 21 is a second local oscillator, 22 is a second intermediate frequency amplifier, 23 is a horizontal axis amplifier, 24 Is a logarithmic amplifier, 25 is a detector, 25 is a video amplifier, 27 is a CRT, 28 is a frequency control unit of the sweep oscillator 19, 29 is a measurement unit, 30 is a spectrum temporary storage unit, and 31 is a level determination unit.

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 local 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 determined by the frequency control unit 28 by the sweep oscillator 19
Set the target frequency of. The waveform input from the input unit 7 to the attenuator 14 passes through the low-pass filter 15, and the output from the sweep oscillator 19 passes through the first local oscillator 17 for each frequency of interest in the first mixer 16. Added. Then, it is amplified by the first intermediate frequency amplifier 18, and the second mixer 2
At 0, the output of the second local oscillator 21 is mixed, and the output voltage that has passed through the second intermediate frequency amplifier 22, the logarithmic amplifier 27, and the detector 25 is applied to the CRT 27 from the spectrum temporary storage unit 30 and the video amplifier 26. In the above configuration, the frequency spectrum measuring unit 8 is roughly divided into a CRT 27, a measuring unit 29, a spectrum temporary storage unit 30, and a level determining unit 31. Hereinafter, the processing methods of the spectrum temporary storage unit 30 and the level determination unit 31 will be described.

In FIG. 3, the frequency control unit 28 measures an arbitrary frequency region and repeatedly outputs the measurement data to the temporary storage unit 30. The level determination unit 31 has a function of transferring the measurement data to the non-volatile memory 10 when the measurement data of the set level or higher is output to the temporary storage unit 30 within the set frequency range. As a result, when the frequency component of the time waveform to the input unit 7 includes the electric field intensity of the set level or more in the frequency range designated in advance, it is possible to detect it.
There is also a method of setting the data to be transferred to the nonvolatile memory 10 regardless of the level of the measurement data held in the temporary storage unit 30.

By taking the above circuit configuration,
The advantage that the level fluctuation of the spectrum in a specific or unspecific frequency range can be automatically monitored occurs.

FIG. 4 is a block diagram of a second embodiment showing another structure of the electromagnetic interference wave measuring apparatus of the present invention. In FIG. 4, 6 is an electromagnetic interference wave measuring device, 7 is an input part of the electromagnetic interference wave measuring device 6, 8 is an electromagnetic interference wave measuring device, 6 is a frequency spectrum measuring part, and 9 is a control part of the electromagnetic interference wave measuring device 6. 10 is a non-volatile memory unit of the electromagnetic interference wave measuring device 6,
Reference numeral 11 is a failure detection receiving unit of the electromagnetic interference wave measuring device 6, and 32 is a time waveform measuring unit.

The present embodiment has a function of starting the activation of the frequency spectrum measuring unit 8 triggered by the input of a time waveform of an arbitrarily set level or more from the input unit 7 in the first embodiment of FIG. Time waveform measuring unit 32 included
Is connected to the frequency spectrum measuring unit 8 and the control unit 9.

In the present embodiment, the frequency spectrum measuring section 8 sets the time waveform input from the input section 7 to the time waveform measuring section 32 to an arbitrary frequency range on condition that the time waveform exceeds a preset trigger level. It is assumed that the setting has the function of starting the measurement. By starting the measurement in the frequency domain with the fluctuation level of the input time waveform, it is possible to easily compare the detected time waveform with the fluctuation in the frequency domain.

FIG. 5 is a diagram showing an application example of the electromagnetic interference wave measuring apparatus 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, 33 is a mobile radio station D
Is.

Hereinafter, a plurality of electromagnetic transmitting stations (broadcast transmitting station 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 effective to observe the frequency level variation for each frequency band of the CB radio that may pass through the electromagnetic transmitting station near the place where the electronic device 5 is installed and the vicinity. 33, which passes through the radiating antennas 4-1, 4-2 and 4-3 of the broadcasting stations A, B and C and the vicinity thereof.
The trigger level is set for each frequency of the mobile radio station D and monitored.

The electromagnetic interference wave propagating in the space is continuously sent to the frequency spectrum measuring section of the electromagnetic interference wave measuring device 6 via the receiving antenna 1, and the frequency component is taken out.
Now, the frequencies of the broadcast transmitting stations A, B, C to be detected and the 33 mobile radio stations D that may pass in the vicinity are set to fA, fB, fC, fD, respectively, and are normally detected by the receiving antenna 1 now. The electric field level at each frequency point (at the time when no electromagnetic interference occurs) is EA, EB, EC, ED
And

At this time, the respective frequencies fA, fB, f
For C and fD, FIG. 6 shows a measurement example of the electromagnetic environment detected at the time when the electromagnetic interference occurs in the electronic device 5 with the trigger level always set to 10% above the fluctuation level. In FIG. 6, the horizontal axis represents frequency and the vertical axis represents the reception level of the electric field of the frequency spectrum. As shown in FIG. 6, the electric field strength at the frequency fD greatly fluctuates from the constant electric field level ED and the constant electric field levels EA, EB, ED at the other frequencies fA, fB, fC are obtained at the time when the electronic device 5 fails. It was verified that it was higher, and it was possible to verify that it was possible to estimate that the electromagnetic interference that occurred was due to the mobile radio station D.

[0031]

As described above, according to the present invention, an electromagnetic wave having a frequency component equal to or higher than an arbitrarily set trigger level is detected in an arbitrarily set frequency range for trigger determination within an arbitrarily designated frequency band. In this case, since it has a function to automatically record the detection time information together with the measurement data, by comparing it with the occurrence of electromagnetic interference, it is possible to estimate and identify the frequency characteristics of the electromagnetic wave that caused the interference and the transmission source. . In addition, 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 apply the present invention to the investigation of the electromagnetic environment.

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

[Brief description of drawings]

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

FIG. 2 is an explanatory diagram showing a measuring method of the frequency measuring unit 8 of the first embodiment.

FIG. 3 is a block diagram showing a configuration example of a basic circuit of a frequency spectrum measuring unit used in the first embodiment.

FIG. 4 is a block diagram showing a configuration of a second exemplary 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.

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

FIG. 7 is an explanatory diagram showing a conventional technique 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 8 ... Frequency spectrum measuring part 9 ... Control part 10 ... Non-volatile memory part 11 ... Fault detection receiving part 12-1, 12-2 ... Modem 13 ... Remote control device 14 ... Attenuator 15 ... Low-pass filter 16 ... First mixer 17 ... First local oscillator 18 ... 1st intermediate frequency amplifier 19 ... Sweeping oscillator 20 ... 2nd mixer 21 ... 2nd local oscillator 22 ... 2nd intermediate frequency amplifier 23 ... Horizontal axis amplifier 24 ... Logarithmic amplifier 25 ... Detector 26 ... Video amplifier 27 ... CRT 28 ... Frequency control unit 29 ... Measuring unit 30 ... Temporary spectrum storage unit 31 ... Level determination unit 32 ... Time waveform measuring unit

Claims (4)

[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 of the frequency spectrum swept by the measuring unit, and whether the frequency spectrum of the trigger determination frequency range arbitrarily specified between the frequency bands on the temporary storage unit is equal to or higher than an arbitrarily set trigger level. A frequency spectrum measurement unit configured by a frequency level determination unit that makes a determination, a control unit that controls the frequency spectrum measurement unit, and a time waveform input to the input unit based on a control signal from the control unit. A memory for storing the frequency spectrum transferred from the frequency spectrum measurement unit together with detection time information of the frequency spectrum when the condition of the trigger level set in the frequency range for trigger determination of the frequency level determination unit or higher is satisfied. An electromagnetic interference wave measuring device comprising: 2. The electromagnetic interference wave measuring device according to claim 1, wherein the control section manually or manually transmits a control command signal transmitted by wire or wirelessly using a telephone line or an optical fiber. Sweep frequency range of measurement part, measurement voltage level, frequency range for trigger judgment,
An electromagnetic interference wave measuring device characterized in that it is possible to change one or more settings among trigger levels. 3. The electromagnetic interference wave measuring device according to claim 1 or 2, wherein the frequency spectrum measuring unit can start activation by using an electric signal from an external device as a trigger. Measuring device. 4. The electromagnetic interference wave measuring device according to claim 1 or 2, wherein the time waveform has a function of starting the activation of the frequency spectrum measuring unit when a time waveform having an arbitrarily set level or higher is input. An electromagnetic interference wave measuring device comprising a measuring unit.