JPH08122379A - Cell for measuring minute electromagnetic wave and generating strong electromagnetic wave - Google Patents

Abstract

PURPOSE: To provide a cell for measuring minute electromagnetic waves and generating strong electromagnetic waves which uniforms the electromagnetic field distribution and shows a frequency characteristic in a wide band. CONSTITUTION: Central conductor wires 8 taken out from a central conductor 6 of a coaxial tube 3 are arranged horizontally in a group via equal distances. Groups of outer conductor wires 9 taken out from an outside conductor 7 of the coaxial tube 3 are arranged in parallel to the group 8 above and below the group 8. Terminals of the groups 8 and 9 are connected each other via resistors 16, and electromagnetic wave absorbers 4 constituting walls are disposed at both sides and a terminal end of the cell. The cell for measuring minute electromagnetic waves and generating strong electromagnetic waves is thus constituted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a cell used for measuring minute electromagnetic waves (signals or noises) in electronic devices and other mobile wireless communication devices, and for irradiating electronic devices with strong electromagnetic waves (strong electric field immunity test). Regarding

[0002]

2. Description of the Related Art Generally, an open field test site as shown in FIG. 14 or an electromagnetic wave anechoic cell as shown in FIG. 15 is used as a means for measuring electromagnetic wave noise generated from electronic equipment and electromagnetic wave signals from mobile radio communication equipment. in use.

In the open field test site shown in FIG. 14, the EUT 21 is placed in the field and the EUT support base 2 is used.
2, the antenna pole 23 is erected at a position apart from the DUT 21, and the antenna 24 is slidably mounted on the antenna pole 23 in the vertical direction. Take the configuration that is connected.

When the radiated electromagnetic noise is evaluated, the electromagnetic wave radiated from the DUT 21 is used as the antenna 2
4 to measure whether or not the electromagnetic wave is below a specified value, and in the case of performing a strong electric field irradiation test, a strong electric field is radiated from the antenna 24 to the EUT 21, An abnormal state, such as malfunction of the EUT 21, is measured.

Further, the electromagnetic anechoic cell shown in FIG. 15 comprises a cell 28 surrounded by an iron plate 27 for shielding an external wave, and carbon is mixed with urethane foam rubber on its inner peripheral wall and ceiling. A large number of wedge-shaped electromagnetic wave absorbers 29 are provided, and the sample holder support 22, the antenna pole 23, the antenna 24, and the sample holder 21 are installed in the cell 28 in the same manner as described above, and the same test is performed. I have to.

As a further advance, T shown in FIG.
The EM cell and the GT shown in FIG.
There is an EM cell. In the TEM cell shown in FIG. 16, the element connected to the high frequency generator 30 is basically a coaxial transmission line, and a flat center conductor plate 32 horizontally arranged in a substantially rectangular cell 31. , The outer conductor plates 33 are arranged in parallel on the upper and lower sides and side faces thereof with a space therebetween, and generate an electromagnetic field between the central conductor plate 32 and the outer conductor plate 33. It is configured to be positioned between the outer conductor plates 33 and used for measurement. A load 35 is connected between the ends of the central conductor plate 32 and the outer conductor plate 33.

This TEM cell is for measuring the test piece 21 by generating a uniform electromagnetic field between the central conductor plate 32 and the outer conductor plate 33, and there is no leakage of electromagnetic waves to the outside.
A relatively stable test can be performed.

However, in the TEM cell, the shape of the cell is almost rectangular, and the upper limit frequency that can be used is lowered due to the abnormal reflection of electromagnetic waves at the internal taper corners, so the GTEM cell shown in FIG. Was developed by this GT
The EM cell is configured so that the shape of the cell 36 does not have a tapered corner portion. That is, it is composed of a flat central conductor plate 37 horizontally arranged in the cell 36, and flat outer conductor plates 38 arranged vertically above and below the flat central conductor plate 37. Similarly, the measurement is performed by arranging it between the central conductor plate 37 and the lower outer conductor plate 38. In the figure, 39 is a high frequency generator, 4
Reference numeral 0 is an electromagnetic wave absorber made of urethane rubber.

[0009]

By the way, since the open test site shown in FIG. 14 cannot be tested in the urban area due to the high level of external environmental electromagnetic noise, it is basically installed outdoors. Therefore, it is inconvenient and the test may not be possible due to weather conditions such as rainfall, snowfall, and strong wind. In addition, the level of the radiated electromagnetic noise of the test device 21 changes due to changes in the outside air temperature, changes in temperature, etc., making it difficult to obtain reproducibility of measurement results. On the other hand, there is a case where a structure such as a measurement hut is installed, but this causes reflection of electromagnetic waves radiated from the DUT 21, which causes a problem of deterioration in characteristics. In particular, a strong electric field irradiation test cannot be performed because it causes electromagnetic interference to the other.

Next, since the electromagnetic wave anechoic cell shown in FIG. 15 has a shield cell structure, the above-mentioned drawbacks are compensated, but there are the following problems. That is, the length of the electromagnetic wave absorber 29 needs to be half the wavelength of the electromagnetic wave to be absorbed, and the radiated electromagnetic wave has a frequency of 30 MHz to 1 GHz.
Then, the electromagnetic wave absorber 29 should be at least 5 m long.

Further, since the floor surface is a total reflection surface of electromagnetic waves, a height pattern is generated, and the effective dimension of the anechoic cell must be 5 m or more. Under these conditions, the outer shell has a length of 19 m, a width of 16 m, and a height of 10 m or more, which is very large and requires a large equipment cost. Further, in the strong electric field irradiation test, since the floor is a total reflection surface of electromagnetic waves, the electric field is disturbed, and therefore the strong electric field irradiation test cannot be performed.

Next, the TEM cell shown in FIG. 16 was developed to solve these problems. Since it constitutes a coaxial transmission line, it is a relatively small cell and a stable test can be performed. However, since the inner wall of the cell is an iron plate that is a shield member, there is reflection of electromagnetic waves, there is disturbance of electromagnetic waves due to the tapered corners inside the cell, and the central conductor plate 32 and the outer conductor plate 33 from the coaxial tube base portion. Since there is a rapid spread, there is an input / output impedance unmatching, and the usable upper limit frequency (cutoff frequency) decreases (the usable frequency for the test equipment 1 m ³ is:
(DC to 150 MHz), there is a limit to the type of EUT 21. In particular, recent mobile wireless communication devices and the like require a test with a used frequency that greatly exceeds 1 GHz, but there is a big problem that this cannot be supported.

In the GTM cell shown in FIG. 17, the operating frequency (cutoff frequency) is extended by eliminating the taper corner in the cell, but the outer conductor plate 38 extends at an angle with respect to the central conductor plate 37. Therefore, the electric field perpendicular to the TEM wave transmission direction has an oblique electric field distribution, and the electromagnetic field inside the cell becomes nonuniform. Therefore, there is a problem in measurement and test stability and reproducibility.

As described above, minute electromagnetic waves (signals or noises) in conventional electronic devices or mobile wireless communication devices
In order to perform the measurement and the irradiation test of strong electromagnetic waves to electronic equipment (strong electric field immunity test), the performance of each measurement and test equipment should be adjusted according to the required measurement or test contents for various EUTs. Had to be used properly, and there were limits to the frequency used for measurement and testing, cost, and efficiency.

In consideration of the above-mentioned conventional problems, the present invention has a uniform electromagnetic field distribution regardless of the size of the cell shape,
Moreover, it is an object of the present invention to provide a cell whose usable frequency extends up to several GHz and which enables measurement and testing of various electronic devices and mobile wireless communication devices.

[0016]

In order to achieve the above-mentioned object, a cell for measuring minute electromagnetic waves and a strong electromagnetic wave according to the present invention comprises:
Equipped with a coaxial tube for connecting a high-frequency generator to test a device such as a malfunction by irradiating a strong electromagnetic wave to a measuring device for minute electromagnetic waves generated from electronic devices or electronic devices,
A central conductor wire group is led out from the central conductor of this coaxial tube and is arranged horizontally, and an outer conductor wire group is led out from the outer conductor of the coaxial tube, and is placed above and below the central conductor wire. It is divided and arranged so that its main part is parallel to the center conductor wire group, and also serves as load and input / output impedance matching between each end of the center conductor wire group and each end of the outer conductor wire group. The resistance groups are connected to each other, and the electromagnetic wave absorbers are arranged so as to form walls on both side portions and terminal portions of these wire groups.

[0017]

In the above structure, the EUT is positioned between the central conductor wire group and the lower outer wire group, and in the measurement of minute electromagnetic waves, the minute electromagnetic wave generated by the EUT is used for the central conductor wire group and the outer conductor wire group. Pick it up with and measure it with a measuring instrument.

Further, in the strong electromagnetic wave irradiation test of the EUT, a high-frequency current is caused to flow from the high-frequency generator to the central conductor wire and the outer conductor wire, an electromagnetic field is generated between them, and this is irradiated to the EUT. . In this irradiation, the operating frequency is increased and at what frequency the EUT malfunctions, for example, is tested.

In this test, the distribution of the electromagnetic field between the central conductor wire group and the outer conductor wire group is uniform. That is, the cell has no taper corner portion and the electromagnetic wave absorbers are arranged on both sides and the end portion of the cell, so that there is almost no reflection of the electromagnetic wave, and thereby the operating frequency can be greatly extended. Furthermore, the outer conductor wire group is arranged at a relatively narrow interval, and this functions as a shield member, and electromagnetic waves do not leak from the inside of the cell or foreign electromagnetic waves do not enter the cell, and a good test can be performed. Become.

[0020]

EXAMPLE A cell for measuring a minute electromagnetic wave and generating a strong electromagnetic wave according to an embodiment of the present invention will be described below.

In FIG. 1, reference numeral 1 denotes a cell, a coaxial tube 3 having an N-type connector 2 is attached to one wall, side surfaces except upper and lower sides, and an electromagnetic wave absorber 4 made of a ferrite plate on a terminal surface. It is arranged. An aluminum plate 5 having a thickness of 1 mm is provided as a shield material on the outer side of the electromagnetic wave absorber 4. As shown in FIG. 2, the coaxial tube 3 has an annular center conductor 6 and an outer conductor 7, is machined from brass, and the support inside the coaxial tube 3 is made from Teflon. The ends of a plurality of center conductor wires 8 are coupled to the center conductor 6 of the coaxial waveguide 3,
Moreover, the outer conductor 7 of the coaxial waveguide 3 is coupled with and guided to the outer conductor 7 of the central conductor wire 8 twice as many as the outer conductor wires 9 (see FIG. 3). The wire connecting portions of the central conductor 6 and the outer conductor 7 are provided with connecting grooves 10 and 11 as appropriate. The center conductor wire 8 and the outer conductor wire 9 are made of copper wire having a diameter of 2 mm.

FIGS. 3 and 4 are views showing the lead-out base portions of the central conductor wire 8 and the outer conductor wire 9 as viewed from the side and the rear side. Each central conductor wire group 8 has a diameter in order from the cylindrical arrangement of the base to the tip. It reaches the insulating support member 12 arranged on one plane while flattening, in which a plurality of groups of conductor wires 8 are laterally equally spaced on one horizontal plane, and in the present embodiment, the upper limit of the used frequency, for example, a wavelength of 3 GHz. 1/10 or less, that is, 2 cm. In addition, each outer conductor wire group 9 is first divided into upper and lower parts, and reaches the insulating support member 13 which is horizontally arranged with a required space above and below the insulating support member 12, and the outer conductor wire group 9 is arranged here. The groups 9 are evenly spaced laterally on the same plane,
That is, they are positioned at an interval of 2 cm and individually above and below each central conductor wire 8 group.

FIG. 5 is a view of the inside of the cell 1 as seen from above, and FIG. 6 is a view of the inside of the cell 1 as seen from the side. Here, the group of central conductor wires 8 is fixed laterally at equal intervals by the insulating support member 12 while reaching the insulating support member 14 at the end while maintaining the horizontal. Similarly, the insulating support member 1
The group of conductor wires 9 outside 3 is horizontally extended at equal intervals in the lateral direction and parallel to the center conductor wire 8, and reaches the insulating support member 15 at the end to fix the end. In FIG. 5, the outer conductor wires 9 and the central conductor wires 8 are vertically overlapped with each other, so that the central conductor wires 8 are not shown. Further, since the insulating support members 12 to 15 do not disturb the input / output impedance, a low dielectric constant, high insulating material is used.

As shown in FIGS. 6 and 7, between the ends of the center conductor wires 8 and the ends of the outer conductor wires 9 corresponding to the upper and lower sides of the center conductor wires 8 are connected to the coaxial tube 3 as a load. A resistor 16 for matching input / output impedance with a measuring instrument, a high frequency generator, etc. is connected. Each resistance value of the resistance group 16 is gradually decreased as it approaches the lateral side of the cell, and the resistance value 16 in the central portion is reduced.
Is the highest, and is 50Ω as a whole in this embodiment.

In the above structure, first, measurement of minute electromagnetic waves (signal or noise) of electronic equipment will be described. The test piece 17 to be measured is set between the central conductor wire group 8 arranged horizontally in the cell 1 and the outer conductor wire group 9 arranged below it, and the test piece 17 is operated. . A signal or noise generated from the operating EUT 17 is picked up by the central conductor wire group 8 and the lower outer conductor wire group 9 and connected to the N-type connector 2 of the coaxial tube 3 (not shown). Measured at. In this measurement,
Only the outer conductor wire 9 group is provided above and below the cell 1, but the signals, noises, external signals, etc.
It is shielded by the group and does not affect the measurements in cell 1.

Next, a strong electromagnetic wave irradiation test will be described. Similarly to the above, the test device 17 is set between the central conductor wires 8 arranged horizontally in the cell 1 and the outer conductor wires 9 below the central conductor wires 8 to generate a high frequency in the N-type connector 2 of the coaxial tube 3. A high-frequency current is passed from the central conductor wire group 8 to the outer conductor wire group 9 by connecting a container (not shown).

In this case, both the central conductor wire 8 group and the outer conductor wire 9 group connected to the coaxial waveguide 3 move from the cylindrical array to the parallel lines with uniform inclination and bulge, so that impedance mismatching occurs. Since the characteristic impedance is constant and the conductor edge is not formed, a transmission line that does not reflect electromagnetic waves up to a high frequency band is formed.

As shown in FIG. 8, an electric field A is generated from the central conductor wire 8 group toward the outer conductor wire 9 group, and a magnetic field B orthogonal to the electric field A is generated. The major feature is that the magnetic field B is the electromagnetic wave absorber 4 on the side of the cell 1.
Since the magnetic field is not disturbed, the EUT is uniformly irradiated with electromagnetic waves.

It should be noted here that the magnetic field lines of the magnetic field B are actually the electromagnetic wave absorber 4 as shown by the broken line in FIG.
A deflection phenomenon occurs in the part that hits. This causes turbulence of electromagnetic waves and is a major cause of suppressing the extension of the used frequency. In the present embodiment, of the load 16 shown in FIG. 7 and the resistance 16 group which is the impedance matching element,
The closer to the electromagnetic wave absorber 4 on the side of the cell 1, the smaller the resistance value is. Therefore, the closer to the electromagnetic wave absorber 4 of the central conductor wire 8 group and the outer conductor wire 9 group, the larger the current is disturbed. As shown in FIG. 8, the magnetic field B becomes stronger toward the end thereof, that is, the deflection of the magnetic field lines of the magnetic field B is corrected, the disturbance of electromagnetic waves is prevented, and the upper limit of the operating frequency is extended to about several GHz, It can be more effective in conducting an electromagnetic wave irradiation test.

FIG. 9 is a SWR characteristic showing the result,
The degree of reflection is as low as about 3 GHz. Of course, the central conductor wire group 8 and the outer conductor wire group 9 are in a parallel relationship, and since the electromagnetic waves are evenly applied to the test device 17, the stability and reproducibility of the test are good. . In addition, the cell 1 has the outer conductor wires 9 arranged on the upper and lower surfaces thereof and is not provided with a shield plate. However, the distance between the groups of the outer conductor wires 9 is set to 1/10 or less of the wavelength of the upper limit frequency of the used frequency, and therefore 2 cm in this embodiment.
Therefore, even if the upper limit of the used frequency is 3 GHz,
The 3 GHz radio wave is captured by the group of outer conductor wires 9 and does not leak to the outside, and it is not necessary to additionally attach a shield plate. As described above, in the micro electromagnetic wave measurement cell and the strong electromagnetic wave generation cell of this embodiment, the distribution of the electromagnetic field is uniform regardless of the size of the shape, and the operating frequency extends up to several GHz. As a facility for measurement and strong electromagnetic wave irradiation test, improve performance and reduce measurement and test costs.

FIG. 10 shows the structure of the essential parts of another embodiment of the present invention. The feature of this embodiment is that the arrangement of the outer conductor wire 9 group with respect to the central conductor wire 8 group in the cell is changed.

As described above, in the case where the electromagnetic wave absorbers 4 are arranged on both sides of the cell, there is a disadvantage that the magnetic field line ends of the magnetic field are deflected, and it is necessary to correct this. Therefore, in this embodiment, among the outer conductor wires 9 corresponding to the central conductor wires 8 arranged, the closer to the electromagnetic wave absorbers 4 on both sides, the smaller the distance from the corresponding center conductor wire 8 is. is there.

The magnetic field B generated by this structure becomes a stronger magnetic field at the magnetic field end, and has the same effect as that of individually changing the resistance value of the group of resistors 16 described above. FIG. 11 shows another embodiment of the present invention, which is configured as a test facility in a production factory, for example. The feature of the present embodiment is that a conveyor 18 made of a non-magnetic material that penetrates the inside of the cell 1 having the configuration of the above-described embodiment is provided, and the tester 17 is placed on the conveyor 18 It is automatically conveyed to the inside of 1 and the minute electromagnetic wave is measured or the strong electromagnetic wave irradiation test is performed. Therefore, the electronic device can be efficiently measured and tested by connecting to the production line. A guide cylinder 19 made of a magnetic material is provided at the entrance and exit of the conveyor 18 in the cell 1 to prevent electromagnetic waves from entering and to suppress reflection of internal electromagnetic waves.

In the cell 1 in each of the above-described embodiments, the distance between the horizontally arranged central conductor wire 8 group and the upper and lower outer conductor wire 9 groups is 1 at the upper portion and 2 at the lower portion as shown in FIG. It may be a ratio. That is, sample 17
The height of the entire cell can be reduced by making only the portion where is located a large interval, and for example, 0.3 m above and 0.6 below.
m, and the overall height can be reduced to 0.9 m.

Although the shield plate is not required above and below the cell 1, the shield plate 20 may be provided outside the upper and lower outer conductor wire groups 9 as shown in FIG. It is possible to more completely block the leakage of electromagnetic waves and the intrusion of external noise.

[0036]

As is clear from the description of the above embodiment,
The micro electromagnetic wave measurement and strong electromagnetic wave generation cell of the present invention is
A central conductor wire group that is derived from the coaxial tube and is disposed horizontally, and an outer wire group that is also derived from the coaxial tube and that is disposed above and below the central conductor wire group in parallel with the central conductor wire group, and Since it is composed of a resistance group for load and impedance matching connected between each central conductor wire and each outer conductor wire and an electromagnetic wave absorber arranged on both sides of the cell, a uniform electromagnetic field can be generated and its frequency used. The upper limit can be greatly extended. Moreover, a part of the shield structure can be omitted and the whole can be downsized, and minute electromagnetic wave measurement and strong electromagnetic wave irradiation test of electronic devices, mobile wireless communication devices, etc. can be accurately and effectively performed. Its value is great.

[Brief description of drawings]

FIG. 1 is a perspective view showing a state in which a member for measuring a minute electromagnetic wave and a cell for generating a strong electromagnetic wave according to an embodiment of the present invention is mounted.

FIG. 2 is a cross-sectional view of a coaxial tube part in the same cell.

FIG. 3 is a sectional side view showing a conductor wire group led out from the coaxial tube portion.

FIG. 4 is a rear view showing a coaxial wire and a conductor wire group led out in the same manner.

FIG. 5 is a plan sectional view of a cell in which a conductor wire group (outer conductor wire group) is arranged.

FIG. 6 is a vertical sectional view of a cell in which a conductor wire group is arranged.

FIG. 7 is a plan view showing an end face of the cell.

FIG. 8 is a layout explanatory diagram of a conductor wire group of the same.

FIG. 9 is a SWR characteristic diagram of the same cell.

FIG. 10 is a layout explanatory view of a conductor wire group according to another embodiment of the present invention.

FIG. 11 is a sectional view of a cell of another embodiment of the present invention.

FIG. 12 is a sectional view of a cell of another embodiment of the present invention.

FIG. 13 is a perspective view of a cell according to another embodiment of the present invention.

[Figure 14] Configuration diagram of conventional open-site measurement and test equipment

FIG. 15 is a sectional view of a conventional electromagnetic anechoic cell.

FIG. 16 is a partially cutaway perspective view of a conventional TEM cell.

FIG. 17 is a partially cutaway perspective view of a conventional GTEM cell.

[Explanation of symbols]

 1 Cell 2 N-type Connector 3 Coaxial Tube 4 Electromagnetic Wave Absorber 8 Center Conductor Wire 9 Outer Conductor Wire 16 Resistance 17 Test Device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04B 7/26 H05K 9/00 M

Claims (9)

[Claims] 1. A coaxial tube for connecting a measuring device or a high frequency generator, and a horizontal conductor which is led out from a central conductor of the coaxial tube,
And a central conductor wire group arranged at equal intervals, and an outer conductor wire group led out from the outer conductor of the coaxial waveguide, in which the central conductor wire group and the main part are arranged in parallel above and below the central conductor wire group. A resistor group connected between the upper and lower corresponding ends of the center conductor wire group and the outer conductor wire group, and a wall provided by arranging both sides and end portions of the center conductor wire group and the outer conductor wire group. Cell for measuring minute electromagnetic wave and generating strong electromagnetic wave, which is composed of eggplant electromagnetic wave absorber. 2. The small electromagnetic wave measurement and the strong electromagnetic wave measurement according to claim 1, wherein the resistance group connected between the ends of the central conductor wire group and the outer conductor wire group has a smaller resistance value as the resistance group is closer to both sides of the cell. Electromagnetic cell. 3. The cell for minute electromagnetic wave measurement and strong electromagnetic wave generation according to claim 1, wherein the outer conductor wire group has a smaller distance between the outer conductor wire group and the central conductor wire facing each other as the outer conductor wires are closer to both sides of the cell. 4. The micro electromagnetic wave measurement and strong electromagnetic wave generation cell according to claim 1, wherein the outer conductor wire group has an interval between adjacent outer wire wires set to 1/10 or less of the wavelength of the upper limit operating frequency. 5. The center conductor wire group and the outer conductor wire group derived from the center conductor and the outer conductor of the coaxial waveguide,
The micro electromagnetic wave measurement and strong electromagnetic wave generation cell according to claim 1, wherein the derived base portion is gradually moved from a cylindrical arrangement in cross section to a flat arrangement. 6. The micro electromagnetic wave measuring and strong electromagnetic wave generating cell according to claim 1, wherein the electromagnetic wave absorber is formed of a ferrite plate. 7. A cell for measuring minute electromagnetic waves and generating a strong electromagnetic wave, comprising a shield plate arranged outside the outer conductor group in the cell according to claim 1. 8. A cell for measuring small electromagnetic waves and generating a strong electromagnetic wave, which is provided with a conveyor for transporting a sample device made of a non-magnetic material that passes between the central conductor wire group and the lower conductor wire group in the cell according to claim 1. . 9. The ratio of the interval of the upper outer conductor wire group to the central conductor wire group and the interval of the lower outer conductor wire group to the central conductor wire group are set to a ratio of 1: 2.
Alternatively, the cell for measuring minute electromagnetic waves and generating strong electromagnetic waves according to 8.