JPH10332754A - Proximity electromagnetic field probe, electromagnetic field measuring device using it, and method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent emitted noise from being transmitted to a measuring cable and a handle part by supporting an antenna receiving emitted electromagnetic wave from an object to be measured with the handle part connected to the measuring cable at an optional angle. SOLUTION: A connector 12 connected to the end part of a coaxial (measuring) cable 10 is formed with posts 14a, 14b on the end part, and their end parts are respectively formed with ring-like supporting parts 16a, 16b. An antenna 18 receiving emitted electromagnetic wave of an object to be measured is formed so that the circumference of a copper wire except both end parts is coated with insulating material 22, terminals 20a, 20b for connecting to the supporting parts 16a, 16b are formed on both end parts, and conductive grease is spread on the contact faces so as to prevent contact from being defective. The antenna 8 is rotated against the supporting parts 16a, 16b, and the shapes of the supporting parts 16a, 16b and the terminals 20a, 20b are set so as to obtain fixed frictional force to be fixed at an optional angle. Hereby, because the angle of the antenna 8 can be optionally set, emitted noise can be prevented from being transmitted to the coaxial cable 10 and the connector 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a proximity electromagnetic field probe for measuring electromagnetic waves radiated from an object to be measured, an electromagnetic field measurement apparatus and an electromagnetic field measurement method using the same.

[0002]

2. Description of the Related Art In recent years, the problem of radiation noise generated from electronic equipment has been emphasized from the viewpoint of EMC (ElectroMagnetic Compatibility). Internationally, CISPR (Comite International Special des Per
Regulations for radiation noise have been proposed by turbations (radio-electriques), and regulations on radiation noise are being promoted while individual regulations are being established in each country. In Japan, voluntary regulations include VCCI
(Voluntary Control Council for Interference by inf
Regulations on radiation noise have been proposed by the Voluntary Control Council for Radio Interference such as ormation technology equipment and information processing equipment.

[0003] In the development of electronic equipment products by manufacturers, when locating the source of radiated noise, measurement is generally performed using a probe for proximity electromagnetic field evaluation, and the electronic equipment conforms to the radiated noise regulation standard. When evaluating whether or not the measurement is performed, the measurement is performed using the prescribed formal measuring device and measuring method. A conventional probe for evaluating a near electromagnetic field will be described with reference to FIGS. FIG. 14 is a top view and a side view showing a conventional probe. 15 and 16 are cross-sectional views showing a measurement method using a conventional probe.

[0004] As shown in FIG.
In No. 9, the loop antenna 118 was formed at the end of the handle 112, and the loop antenna 118 was formed substantially parallel to the handle 112. Specimen 12 using probe 119
When measuring the radiation noise of the electronic component 132a on the antenna 8, as shown in FIG. 15A, the antenna 118 is brought close to the electronic component 132a, and the noise level is reduced by a spectrum analyzer or the like connected via a measurement cable. Can be measured.

[0005]

However, in the conventional probe 119, as shown in FIG.
8 is formed with the concave portion 130,
The antenna 118 could not be brought close to the electronic component 132b. For this reason, the electronic component 132a and the electronic component 132b could not be measured under the same conditions.

Further, as shown in FIG. 16, an electronic component 1 that generates strong radiation noise below the handle 112 or the measurement cable.
When there is 32c, the radiation noise from the electronic component 132c may be transmitted to the handle 112 or the measurement cable. This sometimes makes it difficult to identify the source of the radiation noise. An object of the present invention is to provide a proximity electromagnetic field probe in which radiation noise is hardly transmitted to a handle portion and a measurement cable, and an electromagnetic field measurement device and an electromagnetic field measurement method using the proximity electromagnetic field probe.

[0007]

The object of the present invention is to provide a handle connected to a measuring cable and an antenna supported at an arbitrary angle with respect to the handle and receiving an electromagnetic wave radiated from an object to be measured. This is achieved by a proximity electromagnetic field probe characterized by having: As a result, the angle of the antenna of the proximity electromagnetic field probe can be set arbitrarily, so that the electromagnetic wave radiated from the object to be measured can be selectively selected without being affected by the electromagnetic wave radiated from the electronic component that is not the measurement target. Can be measured.

In the above-mentioned proximity electromagnetic field probe, it is preferable that a scale is attached to the handle or the antenna so that the angle at which the antenna is supported can be visually checked. In the above-mentioned proximity electromagnetic field probe, it is desirable that the antenna is a loop antenna.

In the above-described proximity electromagnetic field probe, two support portions are formed opposite to each other at the end of the handle portion, and the antenna has a plurality of turns and is formed on a straight line passing through the center of gravity. Preferably, two terminals are formed, and the two terminals are respectively coupled to the two supports. In the above-described proximity electromagnetic field probe, it is preferable that the antenna is a rod-shaped antenna.

In the above-mentioned proximity electromagnetic field probe, it is preferable that a conductive grease is applied to a connection portion between the antenna and the handle. Further, the above object is achieved by an electromagnetic field measuring apparatus characterized in that an electromagnetic wave radiated from an object to be measured is measured using the above-mentioned proximity electromagnetic field probe. As a result, the angle of the antenna of the proximity electromagnetic field probe can be set arbitrarily, so that the electromagnetic wave radiated from the object to be measured can be selectively selected without being affected by the electromagnetic wave radiated from the electronic component that is not the measurement target. Can be measured.

Further, the object is to set the angle of the antenna with respect to the handle to a desired angle in accordance with the shape of the specimen by using the above-mentioned proximity electromagnetic field probe, and to set the electromagnetic wave radiated from the object to be measured. Is measured by an electromagnetic field measurement method characterized by measuring As a result, the angle of the antenna of the proximity electromagnetic field probe can be set arbitrarily, so that the electromagnetic wave radiated from the object to be measured can be selectively selected without being affected by the electromagnetic wave radiated from the electronic component that is not the measurement target. Can be measured.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] A proximity electromagnetic field probe according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3 are perspective views of the proximity electromagnetic field probe according to the present embodiment. As shown in FIG. 1, a connector 12 is connected to an end of the coaxial cable 10.

At the end of the connector 12, support columns 14a, 1
4b is formed. It is desirable to use a strong material for the columns 14a and 14b so as to support the antenna 18. At the ends of the columns 14a and 14b,
Ring-shaped support portions 16a and 16b are formed respectively. The columns 14a, 14b and the supporting portions 16a, 16
Each connection method with b may be a connection by soldering or a connection by welding. The support 16
The shapes of the a and 16b are not limited to the ring shape as shown in FIG. 1, but may be a ring shape with a cut in a part, but a good electrical connection with the terminals 20a and 20b of the antenna 18 is possible. It is desirable that the antenna 18 be shaped so that connection can be obtained and the antenna 18 can rotate smoothly.

An antenna 18 bent in a ring shape is connected to the support portions 16a and 16b. Antenna 18
Is formed by covering a copper wire with a coating 22 which is an insulator. The two ends of the antenna 18 are covered with a coating 2.
2 are not formed, and terminals 20a and 20b for connecting to the support portions 16a and 16b are formed. Terminal 20
It is desirable that conductive grease for preventing poor contact be applied to contact surfaces between the support members 16a and 16b and the support portions 16a and 16b.

The antenna 18 rotates with respect to the supporting portions 16a and 16b, and can be fixed at an arbitrary angle.
It is desirable that the shapes of the support portions 16a and 16b and the terminals 20a and 20b are appropriately set so as to obtain a desired frictional force. In this manner, the connector 12, the columns 14a, 1
The proximity electromagnetic field probe 19 according to the present embodiment, which includes the antenna 4 and the support portions 16a and 16b, and the antenna 18, is configured.

Further, as shown in FIG.
The cover 24 may be formed at the end of the zero. Support portions 16a and 16b are connected to the conductors 10a and 10b of the coaxial cable 10 by soldering or the like, respectively. An antenna 18 is coupled to the support portions 16a and 16b. The ends of the coaxial cable 10, the support portions 16a, 16b,
Further, both ends of the antenna 18 are fixed so as to be sandwiched between the covers 24a and 24b.

As shown in FIG. 3, a scale indicating the angle of the antenna 18 with respect to the cover 24 may be provided on the cover 24. A circular member 21 is provided near the terminal 20 a of the antenna 18. The circular member 21 is provided with a mark 26a indicating the reference of the position of the antenna 18. On the other hand, the cover 24 is provided with a scale 26b around the joint with the circular member 21 to indicate the angle of the antenna 18 with respect to the cover 24. Thereby, the cover 24
, The angle of the antenna 18 with respect to.

Next, a measuring method using the proximity electromagnetic field probe according to the present embodiment will be described. First, a measurement method in the case where electronic components to be measured are formed on the planar region of the specimen and in the recess, respectively, will be described with reference to FIG. FIG. 4 is a cross-sectional view illustrating a measuring method using the proximity electromagnetic field probe according to the present embodiment.

The specimen 28 has a plane area as shown in FIG. 4A and an area in which a recess 30 is formed as shown in FIG. 4B. For example, an electronic component 32a is provided on a plane area of the test piece 28, and an electronic component 32b is provided in the concave portion 30 of the test piece 28, for example. In the measurement, it is desirable that the distance between the electronic component 32a and the antenna 18 and the distance between the electronic component 32b and the antenna 18 be the same. Therefore, when measuring the electronic component 32b in the concave portion 30, the proximity electromagnetic field probe 19 or the measurement cable 10
It is desirable to appropriately set the angle of the antenna 18 with respect to the connector 12 so as not to hit the connector 8. Here, the angle is set to, for example, 45 degrees according to the shape of the concave portion 30.

As described above, in the proximity electromagnetic field probe 19 according to the present embodiment, the angle of the antenna 18 with respect to the connector 12 can be set arbitrarily.
Even when b is formed in the concave portion 30, the measurement can be performed without any problem. Next, taking a case where the electronic components are formed adjacent to each other as an example, a measurement method and a measurement result using the proximity electromagnetic field probe according to the present embodiment will be described with reference to FIGS.
This will be described with reference to FIG. 5 to 10 are a top view and a side view showing the measurement method using the proximity electromagnetic field probe according to the present embodiment, and a graph showing the measurement results.

As shown in FIG. 5 to FIG.
An electronic component 34a and an electronic component 34b are formed adjacent to each other. The measurement object is the electronic component 34a. The angle of the antenna 18 with respect to the connector 12 is 0 degree, 45 degrees.
And 90 degrees, and for each setting, the connector 1 is placed on a straight line connecting the electronic component 34a and the electronic component 34b.
2, the electronic component 34a and the electronic component 34b
Connector 12 on a straight line substantially perpendicular to the straight line
Was measured, and a total of six types of measurement results were obtained.

First, as shown in FIG. 5, the angle of the antenna 18 with respect to the connector 12 is set to 0 degree, and the electronic components 34a
The measurement was performed such that the connector 12 was positioned on a straight line connecting the electronic component 34b and the electronic component 34b. Next, as shown in FIG. 6, the angle of the antenna 18 with respect to the connector 12 is set to 0 degree, and the connector 12 is positioned on a straight line substantially perpendicular to a straight line connecting the electronic components 34a and 34b. It was measured.

Next, as shown in FIG. 7, the angle of the antenna 18 with respect to the
The measurement was performed such that the connector 12 was positioned on a straight line connecting the electronic component 34a and the electronic component 34b. Next, as shown in FIG.
The measurement was performed such that the angle of the antenna 18 with respect to the connector 12 was 45 degrees, and the connector 12 was positioned on a straight line substantially perpendicular to a straight line connecting the electronic components 34a and 34b.

Next, as shown in FIG. 9, the angle of the antenna 18 with respect to the connector 12 is set to 90 degrees,
The measurement was performed such that the connector 12 was positioned on a straight line connecting the electronic component 34a and the electronic component 34b. Next, as shown in FIG. 10, the angle of the antenna 18 with respect to the connector 12 is set to 90 degrees, and the connector 12 is positioned on a straight line substantially perpendicular to a straight line connecting the electronic components 34a and 34b. It was measured.

As a result of measurement under these conditions, the peak values indicated by the spectrum analyzer are 43.171, respectively.
dBμV, 35.296 dBμV, 40.671 dBμ
V, 37.062 dBμV, 37.234 dBμV, 3
7.359 dBμV. Comparing the measurement results shown in FIGS. 5 and 6, there is a difference of 7.875 dB. In the measurement method shown in FIG.
Is close to the electronic component 34b, the electronic component 34b
The measurement value is high because the electromagnetic wave radiated from is transmitted to the connector 12 or the coaxial cable 10. On the other hand, in the measurement method shown in FIG. 6, the measured value is low because the connector 12 and the coaxial cable 10 are close to the ground pattern on the specimen 28. Therefore, the connector 12
The measurement method of setting the angle of the antenna 18 to 0 degree with respect to the electronic component 34b formed on the specimen 28 is likely to be affected by the ground pattern and is considered to be undesirable.

When comparing the measurement results shown in FIGS. 7 and 8, there is a difference of 3.609 dB. When the angle of the antenna 18 with respect to the connector 12 is 0 degree, the difference between the measurement results is 7.875 dB, but when the angle is 45 degrees, the difference between the measurement results is reduced to 3.609 dB. It is considered that this is because the distance between the connector 12 and the coaxial cable 10 and the test piece 28 was increased, and the influence of the electronic component 34b and the ground pattern was reduced. Therefore,
A measurement method in which the angle of the antenna 18 with respect to the connector 12 is set to 45 degrees is considered to be a more preferable measurement method than a measurement method in which the angle is set to 0 degrees.

When the measurement results shown in FIGS. 9 and 10 are compared, the difference is only 0.125 dB. Connector 12
When the angle of the antenna 18 with respect to the angle was 45 degrees, the difference in the measurement results was 3.609 dB, but when the angle was 90 degrees, the difference in the measurement results decreased to 0.125 dB. This is because the connector 12 and the coaxial cable 10 and the specimen 28
It is probable that the distance between them was longer than in the case of the measuring methods shown in FIGS. 7 and 8, and was hardly affected by the electronic component 34b and the ground pattern. Therefore, the measurement method in which the angle of the antenna 18 with respect to the connector 12 is set to 90 degrees is considered to be a more preferable measurement method than the measurement method in which the angle is set to 45 degrees.

The shape of the specimen is not limited to the shapes shown in FIGS. 5 to 10, and it is not always desirable to set the angle of the antenna 18 with respect to the connector 12 to 90 degrees. Therefore, it is desirable that the angle of the antenna 18 with respect to the connector 12 be appropriately set in accordance with the shape of the specimen. In addition, the angle of the antenna 18 with respect to the connector 12 is not limited to being always set to be constant, and may be appropriately set for each electronic component to be measured depending on the shape of the specimen.

As described above, according to the present embodiment, the angle of the antenna of the proximity electromagnetic field probe can be set arbitrarily, so that the antenna is not affected by electromagnetic waves radiated from electronic components that are not the object of measurement. Electromagnetic waves emitted from the measurement object can be selectively measured. [Second Embodiment] A proximity electromagnetic field probe according to a second embodiment of the present invention will be described with reference to FIG. FIG. 11 is a perspective view showing the proximity electromagnetic field probe according to the present embodiment.
The same components as those of the proximity electromagnetic field probe according to the first embodiment shown in FIGS. 1 to 10 are denoted by the same reference numerals, and description thereof will be omitted or simplified.

The proximity electromagnetic field probe 19 according to the present embodiment
The main feature of the first embodiment is that the number of turns of the antenna 18 is increased in order to improve the sensitivity of the antenna 18. Since the number of windings is plural and the antenna 18 is heavy, the supporting portion 1
It is difficult to keep the angle of the antenna 18 constant by the respective frictional forces between the terminals 6a and 16b and the terminals 20a and 20b. For this reason, the terminals 20a and 20b are formed so as to be located on a straight line passing through the center of gravity of the antenna 18, so that the antenna 1
8 is prevented from rotating with respect to the connector 12.

Further, as shown in FIG.
May be provided with the cover 36 and the cover 24. By providing the cover 24, the heavy antenna 18 covered with the cover 36 can be supported. As shown in FIG. 13, a scale indicating the angle of the antenna 18 with respect to the cover 24 may be provided on the cover 24. The circular member 21 bonded to the terminal 20a is fitted in a circular concave portion 25 provided in the cover 24. The cover 24 around the circular member 21 is fitted with the cover 24.
Is provided with a scale 26b indicating the angle of the antenna 18 with respect to. Thereby, the antenna 1 with respect to the cover 24
An angle of 8 can be seen.

As described above, according to the present embodiment, even if the antenna has a large number of turns, the angle of the antenna can be set arbitrarily, so that the antenna is affected by electromagnetic waves radiated from electronic components that are not the object of measurement. Without this, it is possible to selectively measure the electromagnetic waves radiated from the device under test. Further, since the number of windings of the antenna is large, it is possible to provide a proximity electromagnetic field probe with high sensitivity.

[Modified Embodiment] The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the first and second
In the embodiment, since the antenna only needs to be able to receive the electromagnetic wave, the shape is not limited to the loop shape, and may be, for example, a rod shape.

In the first and second embodiments, only the magnetic field component may be detected by electrostatically shielding the antenna. In addition, in the first and second embodiments, the position at which the scale is provided is not limited to the cover, and may be, for example, a circular member.

[0035]

As described above, according to the present invention, since the angle of the antenna can be set arbitrarily, the proximity electromagnetic field probe, which makes it difficult for the radiation noise to be transmitted to the handle and the measuring cable, and the proximity electromagnetic field probe An electromagnetic field measuring apparatus and an electromagnetic field measuring method using the same can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a proximity electromagnetic field probe according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a modification of the proximity electromagnetic field probe according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing another modification of the proximity electromagnetic field probe according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a measuring method using the proximity electromagnetic field probe according to the first embodiment of the present invention.

5A and 5B are a top view and a side view showing a measurement method using the proximity electromagnetic field probe according to the first embodiment of the present invention, and a graph (part 1) showing the measurement results.

6A and 6B are a top view and a side view showing a measurement method using the proximity electromagnetic field probe according to the first embodiment of the present invention, and a graph (part 2) showing the measurement result.

FIGS. 7A and 7B are a top view and a side view showing a measurement method using the proximity electromagnetic field probe according to the first embodiment of the present invention, and a graph (part 3) showing the measurement results.

8A and 8B are a top view and a side view showing a measurement method using the proximity electromagnetic field probe according to the first embodiment of the present invention, and a graph (part 4) showing the measurement results.

FIGS. 9A and 9B are a top view and a side view showing a measurement method using the proximity electromagnetic field probe according to the first embodiment of the present invention, and a graph (part 5) showing the measurement results.

10A and 10B are a top view and a side view showing a measurement method using the proximity electromagnetic field probe according to the first embodiment of the present invention, and a graph (part 6) showing the measurement result.

FIG. 11 is a perspective view showing a proximity electromagnetic field probe according to a second embodiment of the present invention.

FIG. 12 is a perspective view showing a modification of the proximity electromagnetic field probe according to the second embodiment of the present invention.

FIG. 13 is a perspective view showing another modification of the proximity electromagnetic field probe according to the second embodiment of the present invention.

FIG. 14 is a top view and a side view showing a conventional probe.

FIG. 15 is a cross-sectional view showing a measurement method using a conventional probe.

FIG. 16 is a cross-sectional view showing a measurement method using a conventional probe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Coaxial cable 10a, 10b ... Lead wire 12 ... Connector 14a, 14b ... Post 16a, 16b ... Support part 18 ... Antenna 19 ... Proximity electromagnetic field probe 20a, 20b ... Terminal 21 ... Circular member 22 ... Coating 24, 24a, 24b ... Cover 25 ... concave portion 26a ... mark 26b ... scale 28 ... sample 30 ... concave portion 32a, 32b ... electronic component 34a, 34b ... electronic component 36 ... cover 112 ... pattern portion 128 ... sample 132a, 132b, 132c ... electronic component 134a, 134b: electronic component 130: recess

Claims (8)

[Claims] 1. A proximity electromagnetic device comprising: a handle connected to a measurement cable; and an antenna supported at an arbitrary angle with respect to the handle and receiving an electromagnetic wave radiated from an object to be measured. Field probe. 2. The proximity electromagnetic field probe according to claim 1, wherein a scale is attached to the handle or the antenna so that an angle at which the antenna is supported can be visually checked. Electromagnetic field probe. 3. The proximity electromagnetic field probe according to claim 1, wherein the antenna is a loop antenna. 4. The proximity electromagnetic field probe according to claim 3, wherein two support portions are formed opposite to each other at an end of the handle portion, and the antenna has a plurality of turns and passes through a center of gravity. A proximity electromagnetic field probe, wherein two terminals are formed on a straight line, and the two terminals are respectively coupled to the two support portions. 5. The proximity electromagnetic field probe according to claim 1, wherein the antenna is a rod-shaped antenna. 6. The proximity electromagnetic field probe according to claim 1, wherein a conductive grease is applied to a connection between the antenna and the handle. Electromagnetic field probe. 7. An electromagnetic field measuring apparatus for measuring an electromagnetic wave radiated from an object to be measured using the proximity electromagnetic field probe according to any one of claims 1 to 6. 8. The antenna according to claim 1, wherein an angle of the antenna with respect to the handle is set to a desired angle in accordance with a shape of a specimen. An electromagnetic field measurement method characterized by measuring an electromagnetic wave radiated from an object.