JP2005241421A - Interference excluding capability testing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an interference excluding capability testing apparatus which can obtain uniform electromagnetic field distribution in a test plane even for an apparatus using a plurality of antennas and a plurality of electric power amplifiers. <P>SOLUTION: The interference excluding capability testing apparatus 1 comprises an RF anechoic chamber 7, a signal generator 10 generating a high-frequency signal, a plurality of radiation antennas 5, a plurality of electric power amplifiers 13, a plurality of output level adjusters 18, a turntable 3 for mounting an instrument to be tested 2 at one end of the RF anechoic chamber 7, a stand 6 for placing the radiation antennas 5 at the other end of the RF anechoic chamber 7, one or more level detectors 16 detecting an electromagnetic level in the test plane, and a controller 19. The controller 19 controls each output level adjuster 18 so that a detection level outputted by the level detector 16 becomes a predetermined value and radiates electromagnetic waves toward the instrument to be tested 2 from each corresponding radiation antenna 5 so that uniform electric field distribution is provided in the test plane. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a disturbance rejection capability test apparatus for testing a disturbance rejection capability (also referred to as immunity) of an electronic device.

In recent years, the sophistication and complexity of electronic equipment has led to the complication of the electromagnetic environment surrounding electronic equipment, and the malfunction of electronic equipment due to radiated disturbances has become a problem. In particular, malfunctions such as medical equipment and mass transit equipment are life-threatening and have become a social problem, and it is required to accurately grasp and improve the resistance (immunity characteristics) of electronic equipment to external disturbance waves.
An immunity test system for specimens such as electronic equipment is a radiated electromagnetic field test method in which specimens are placed in an anechoic chamber and electromagnetic waves are applied to the specimen from a biconical antenna or a log-periodic antenna fixed in the same anechoic chamber. There is also a TEM waveguide method using a TEM cell, a GTEM cell, or the like.
In immunity tests, the test equipment must be placed in a uniform electromagnetic field area, so a non-conductive alignment board with multiple alignment means in a given area. There is known a device in which the uniformity of the electromagnetic field in the area is maintained by attaching a probe for measuring the electromagnetic field level to the measurement point via the alignment means. (For example, refer to Patent Document 1).

JP-A-11-174101

However, in the proposed technique, electromagnetic waves are radiated to the EUT using a single amplifier / antenna, so even if the electric field strength of the test radio wave radiated from the antenna is relatively low, the product (test There is no problem if it can withstand enough depending on the usage status of the equipment), but for example, if it travels near a guidance radar device used for taking off and landing of an aircraft on a moving body such as an automobile equipped with the product, the electronic equipment mounted on the vehicle It has been found that problems such as the malfunctioning of the system may cause it to malfunction, and in some cases may result in a fatal failure that affects human life.

  Therefore, in order to solve this problem, we tried to increase the electric field strength of the test radio wave. However, the electric field strength of 600 V / m is required, and this is realized with a single amplifier / antenna as in the proposed technique. In this case, not only a high withstand voltage antenna is required, but also a high withstand voltage / high output power amplifying device is required, and the electromagnetic wave generator is physically enlarged, and the interference rejection capability test device is also large. There was a problem of becoming. In addition, there is a problem that the cost becomes high.

Therefore, the present application has been made to solve these problems, and the purpose of the present invention is to use a conventional low-withstand-voltage antenna or a low-withstand-voltage test apparatus, even if it is a disturbance exclusion capability test apparatus that can radiate radio waves with high electric field strength. An object of the present invention is to provide a disturbance exclusion capability test apparatus that can use a power amplifying apparatus with a withstand voltage and low output.
Another object of the present invention is to provide a disturbance rejection capability test device that can radiate radio waves with high electric field strength using multiple antennas and multiple power amplifiers, and can provide a uniform electromagnetic field distribution in the test plane. It is to provide an exclusion capability testing device.
Another object is to use a test plane that is capable of radiating high-field strength radio waves using multiple antennas and multiple power amplifiers without being affected by its strong electromagnetic waves. It is an object of the present invention to provide a disturbance exclusion capability test apparatus capable of obtaining a uniform electromagnetic field distribution.

In order to solve the above-mentioned problems, the invention of claim 1 is an interference immunity testing device, wherein an anechoic chamber, a signal generator for generating a high frequency signal, a plurality of radiating antennas, a plurality of power amplifying devices, , A plurality of output level adjusters, a turntable for placing the test equipment on one end of the anechoic chamber, a pedestal for installing the radiation antenna on the other end of the anechoic chamber, One or more level detectors for detecting the electromagnetic field level in the test plane, and a controller, the controller controls each output level adjuster so that the detection level output from the level detector becomes a predetermined value. It is configured to control and radiate an electromagnetic wave from each corresponding radiation antenna toward the EUT so as to have a uniform electric field distribution in the test plane.

According to a second aspect of the present invention, there is provided the interference rejection capability testing apparatus according to the first aspect, wherein the level detector converts a detector into an electric signal corresponding to an electromagnetic wave level, and converts the detected electric signal into an optical signal. The level detector and the control device are configured to be connected via an optical cable.

As described in detail above, according to the invention of claim 1, in the interference rejection capability testing apparatus, the radio wave anechoic chamber, the signal generator for generating a high frequency signal, the plurality of radiating antennas, and the plurality of power amplifying devices. A plurality of output level adjusters, a turntable for placing the test equipment on one end of the anechoic chamber, a pedestal for installing the radiation antenna on the other end of the anechoic chamber, , One or more level detectors for detecting the electromagnetic field level in the test plane, and a control device, each of the output level adjusters so that the detection level output from the level detector becomes a predetermined value. And configured to radiate electromagnetic waves from the corresponding radiating antennas toward the EUT so as to have a uniform electric field distribution in the test plane.
It is possible to provide a disturbance rejection capability testing apparatus that can use a conventional low withstand voltage antenna or a low withstand voltage / low output power amplification device, even if it is a disturbance rejection capability test apparatus that can radiate radio waves with high electric field strength. .
In addition, even if it is a disturbance exclusion capability test device that can radiate radio waves of high electric field strength using multiple antennas and multiple power amplifiers, it can perform a disturbance rejection capability test that can obtain a uniform electromagnetic field distribution on the test plane. An apparatus can be provided.

According to a second aspect of the present invention, in the interference rejection capability testing apparatus according to the first aspect, the level detector converts a detector into an electric signal corresponding to the electromagnetic wave level, and the detected electric signal is an optical signal. Because the level detector and the control device are configured to be connected via an optical cable.
Even if it is a disturbance exclusion capability test device that can radiate radio waves with high electric field strength using multiple antennas and multiple power amplifiers, it is not affected by its own strong electromagnetic waves, and is uniform in the test plane. It is possible to provide a disturbance exclusion capability test device capable of obtaining a distribution.

Hereinafter, an example of an embodiment embodying the present invention will be described in detail with reference to the drawings.

FIG. 1 is an explanatory diagram of a disturbance exclusion capability test apparatus to which the present invention is applied. FIG. 2 is a block diagram of the electromagnetic wave generator, and FIG. 3 is an explanatory diagram showing an installation example of the radiation antenna.
1 is an interference immunity testing device, and a radio wave absorber is attached to the entire surface of the anechoic chamber 7 and reflected by electromagnetic waves radiated into the anechoic chamber and the test equipment. The electromagnetic wave is absorbed by the radio wave absorber and converted into heat energy.
Inside the radio anechoic chamber 7, a turntable 3 is provided on one end side, and a test equipment 2 (also referred to as a specimen) is placed on the turntable 3. On the other end side, an antenna column 4 is provided via a gantry 6 so that the position of radiating radio waves can be changed. A plurality of radiation antennas 5 are installed on the antenna support 4.

Next, the electromagnetic wave generator 17 will be described in detail with reference to FIG. The electromagnetic wave generation device 17 includes a transmission device 15, a radiation antenna 5, a control device 19, and a level detector 16.
The transmitter 15 includes a signal generator 10, a distributor 11, a phase shifter 12, an output level adjuster 18, a power amplifier 13, and a circulator 14.
Reference numeral 10 denotes a signal generator. In this embodiment, an oscillator that sweeps 1 to 1.5 GHz is used.
Reference numeral 11 denotes a distributor for distributing a signal output from the signal generator 10.
12 (12-1 to 12-12) are phase shifters, and in order to obtain a uniform electric field distribution on the measured surface (also referred to as a test plane) of each radiation antenna, the phase of the electromagnetic wave radiated from each radiation antenna is measured. Is for adjusting the phase so that all are in phase on the surface to be measured. It is not necessary to adjust the length of the transmission line from the signal generator to the radiation antenna. Moreover, you may adjust the attachment position of a radiation antenna by moving back and forth with respect to the radiation direction of a radiation antenna.

Reference numeral 18 denotes an output level adjuster, and in order to obtain a uniform electric field in the test plane, level fluctuations caused by path length differences of propagation paths from the respective radiation antennas 5 (5-1 to 5-12) to the test plane and , It is provided to absorb variations in electrical characteristics (especially amplification factor) of equipment. In the present embodiment, an attenuator that attenuates a high-frequency signal is used. The attenuator is provided on the input side of the power amplifying device 13, but may be provided on the output side. Further, when the power amplifying device 13 has a function capable of adjusting its own amplification factor, the amplification factor may be adjusted.
Reference numeral 13 (13-1 to 13-12) denotes a power amplifier.

14 (14-1 to 14-12) is a circulator, and the electromagnetic wave radiated from the radiating antenna 5 is reflected by the metal part of the EUT and is received by the radiating antenna. This is to prevent the power amplifying apparatus 13 from malfunctioning or failing in advance. In this embodiment, no terminating resistor is used, but it may be connected as necessary. In this embodiment, a circulator is used, but an isolator may be used.
The control device 19 is for controlling the output level adjuster 18 so that the output level of the input level detector 16 (16 in this embodiment) becomes a predetermined value.

Next, the configuration of the level detector 16 will be described with reference to FIG. The level detector 16 includes a receiving antenna 20, a detector 21, and an electrical / optical converter 22, and an output signal of the level detector 16 is connected to the control device 19 via an optical fiber cable 24. In addition, the level detector 16 has a portion other than the receiving antenna 20 (specifically, the detector 21 and the electrical / optical converter 22) housed in an electromagnetic shield case to reduce the influence of electromagnetic waves, and is made compact. Yes. As a result, the interference rejection capability test can be performed without disturbing the uniform electromagnetic field on the test plane. In FIG. 5, the signal lines output from the control device 19 to the output level adjuster 18 are not shown.

Next, a method for installing the level detector 16 will be described. As shown in FIG. 4, the level detector 16 is set so that 16 points (4 rows and 4 columns) are equidistant from the test plane as measurement points (16-1 to 16-16) for level detection. It is. In the present embodiment, 16 pieces are used, but the number is not limited to this, and may be 15 pieces or less, or 17 pieces or more.
Reference numeral 30 denotes a support for holding the level detector 16 on the test plane, and a material with extremely low reflection and absorption of electromagnetic waves in order to efficiently radiate the electromagnetic waves radiated from the radiation antenna 5 to the EUT 2. Is used. In this embodiment, non-conductive plastic is used which has low reflection and loss of high frequency signals.

Next, the installation situation of the radiation antenna 5 in the present embodiment will be described. As shown in FIG. 3, antenna posts 4 a, 4 b, and 4 c are placed on the top of the gantry 6. Four radiating antennas 5 are installed on each of the columns, and a total of 12 (5-1 to 5-12) are used. In the present embodiment, the installation interval of the radiation antenna is set to 0.5 times or more the wavelength λ of the radiated electromagnetic wave. In addition, the gantry 6 can move freely on the floor surface of the anechoic chamber 7.

Next, the operation will be described. The sweep signal of 1 to 1.5 GHz generated by the signal generator 10 is distributed by the distributor 11 so as to have the same number as that of the radiating antenna 5, and the power is passed through each phase shifter 12 and the output level adjuster 18. Amplification is performed by an amplifying device 13 (in this embodiment, twelve 420W units are used). The amplified high-frequency signal is supplied to the radiating antenna 5 via the circulator 14 (in this embodiment, 12 Yagi / Uda type antennas having a gain of 8 dBi are used). The electromagnetic waves radiated from the radiating antennas (5-1 to 5-12) are synthesized in the space and generate a uniform electromagnetic field of 600V / m on the test plane of the turntable 3 on which the EUT 2 is placed. Let

At this time, the phase and amplitude are adjusted by the phase shifter 12 and the output level adjuster 18 already described in order to generate a uniform electromagnetic field on the test plane.
If it is necessary to change the test plane due to the size of the EUT 2 placed on the turntable 3 or the position of the test site, the gantry 6 on which the antenna support column is placed is operated. Thus, the radiation antenna 5 is moved so that electromagnetic waves can be radiated to the test plane.
In this embodiment, since the phase shifter 12 and the output level adjuster 18 are provided between the distributor 11 and the power amplifier 13, the withstand voltage of the phase shifter 12 and the output level adjuster 18 can be reduced. effective. However, when there is a margin in the withstand voltage, the present invention is not limited to this, and it may be provided anywhere on each distribution line of the distributor 11.

  Next, the operation of the control device 19 will be described. As described above, the output signals of the plurality of level detectors 16 are input to the control device 19 via the optical cable 24, and the output signals of the level detectors 16 are output so as to have predetermined values. The level adjuster 18 is controlled. In this case, the control amount is weighted by the propagation distance between each level detector 16 and each radiation antenna 5. Specifically, the weighting coefficient is increased as the propagation distance is shorter. With this configuration, a uniform electromagnetic field can be realized over the entire test plane.

Next, the required number of radiating antennas and how to obtain the antenna gain will be described.
First, according to the inventors, when the distance L between the EUT 2 and the radiating antenna is 1 m, a single antenna with a gain of 0 dB is used to achieve an electric field strength of 600 V / m on the test plane. It was found that about 30KW was required as the output of the machine. It was also found that the terminal voltage at this time was about 1200 V (50 ohms).

Therefore, in this embodiment, since 12 radiating antennas 5 are used in a stack, it was found that 2.8 KW can be adequately provided when they are combined in the same phase. In this case, the terminal voltage is about 370 V (50 ohms). Thus, by arranging the radiation antenna 5 on the stack and connecting the power amplification device 13 to each of them, the withstand voltage of the power amplification device 13 and the radiation antenna 5 can be lowered. Further, the withstand voltage can be further reduced by using a high gain antenna. For example, if an 8 dBi antenna is used, the power is 420 W and the withstand voltage is 150 V. If a 20 dBi antenna is used, the power is 28 W and the withstand voltage is 37 V.
Therefore, the type, required quantity, and antenna gain of the radiating antenna may be appropriately selected according to the test frequency and the size of the EUT 2 (in other words, the size of the test plane).
In the above description, the distance L between the EUT 2 and the radiating antenna is 1 m, but it may be appropriately selected within a range of 1 to 3 m. Increasing the distance L increases the transmission loss in space, so it is necessary to increase the transmission power or change the antenna gain to a larger one. If the test plane is to be widened, the gain of the radiating antenna must be set low.

It should be noted that the present invention is not limited to the above-described embodiment, and can be implemented by appropriately changing each part without departing from the spirit of the present invention, as exemplified below.
For example, in this embodiment, twelve radiation antennas and power amplifiers are used, but the number may be larger or smaller than this. Moreover, although 1-1.5 GHz was used as a test frequency in a present Example, it is not limited to this, If it is VHF band-SHF band, it can be used. In this case, an appropriate antenna (Yagi / Uda type antenna, helical antenna, electromagnetic horn) may be used according to the test frequency.

It is explanatory drawing of the disturbance exclusion capability test apparatus to which this invention is applied. It is a block diagram of an electromagnetic wave generator. It is explanatory drawing which shows the example of installation of a radiation antenna. It is explanatory drawing which shows the example of arrangement | positioning of a level detector. It is a block diagram of a level detector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Interference exclusion capability test apparatus, 2 ... Test equipment, 3 ... Turntable, 4 ... Antenna support | pillar, 5 ... Radiation antenna, 6 ... Mount, 7 ... Anechoic chamber, 10 ... Signal generator, 11 ... Divider , 12 ... phase shifter, 13 ... power amplifier, 14 ... circulator, 15 ... transmitter, 16 ... level detector, 17 ... electromagnetic wave generator, 18 ... output level adjuster, 19 ... control device, 20 ... receiving antenna , 21 ... detector, 22 ... electrical / optical converter, 24 ... optical cable, 30 ... support.

Claims (2)

In the interference exclusion capability test equipment,
An anechoic chamber,
A signal generator for generating high-frequency signals;
Multiple radiating antennas,
A plurality of power amplifiers;
Multiple output level adjusters;
A turntable for mounting the EUT on one end of the anechoic chamber;
A stand for installing the radiation antenna at the other end of the anechoic chamber;
One or more level detectors for detecting the electromagnetic field level in the test plane;
A control unit;
And the control device controls each output level adjuster so that the detection level output from the level detector becomes a predetermined value, and each of the corresponding level adjusters so as to obtain a uniform electric field distribution in the test plane. An interference exclusion capability testing apparatus that radiates electromagnetic waves from a radiation antenna toward the EUT.
The level detector is a detector that converts an electric signal corresponding to the level of electromagnetic waves;
2. The electric / optical converter for converting the detected electric signal into an optical signal, and the level detector and the control device are connected via an optical cable. The interference exclusion capability test device described.

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