JPH06242161A - Tem cell - Google Patents

Abstract

PURPOSE:To provide a TEM cell which has a small size, can be handled easily, and can be used for so far as a sufficiently high frequency. CONSTITUTION:On an input end side of an outer conductor 3, its both side faces and upper side face are formed into a tapered shape which extends from the position of a coaxial connector 2 connected to a high frequency signal source toward a TEM cell examination space part. On the terminal side, only both side parts of the outer conductor 3 are narrowed taperingly toward the connection part to a coaxial load 10 additionally so that a part, having the predetermined length in the examination space part has an approximately rectangular cross section. The cell is formed so that a taper part length from the examination space part. to the terminal end is shorter than the length of the taper part on the input end side, while a central conductor 4 is arranged in an inner space surrounded by the outer conductor 3 along the upper face part of the outer conductor 3 so that it dose not touch the outer conductor 3. In the examination space part, the central conductor 4 is arranged in the position which is close to the upper face part of the outer conductor 3 and makes the largest actual examination space between the lower face part and it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a TEM cell, and in particular, a TEM suitable for use in conducting noise resistance test, electric field strength calibration test, reception sensitivity test, electromagnetic radiation property test, etc. of electronic equipment. Regarding cells.

[0002]

2. Description of the Related Art As a prior art relating to a TEM cell, a TEM cell developed in the United States NBS (National Bureau of Standards) as a device for accurately generating an electric field of a known TEM wave for the purpose of electric field strength calibration ( Transvers Electromagnetic Cell) is known. This device is not only for the purpose of electric field strength calibration, but also for the ability to remove EMI in electronic devices, electronic components, receivers, etc.
That is, it is widely used for testing electromagnetic susceptibility or electromagnetic protection level and electromagnetic interference elimination capability.

FIG. 3 is a perspective view showing an example of the above-mentioned conventional TEM cell. In FIG. 3, 1 is a high frequency signal source, 2 is a coaxial connector, 3 is an outer conductor, 4 is a center conductor, 5 is a center conductor support rod, 6 is a sample housing door, 7 is an input / output and power source terminal, and 8 Is a sample, 9 is an insulating base for the sample, 10 is a coaxial load, and 11 is a TEM cell.

A prior art TEM cell 11 shown in FIG.
Is for generating a uniform electromagnetic field in the space formed by the outer conductor 3 and the central conductor 4, and has a test space portion having a substantially rectangular cross section surrounded by the conductor and both ends thereof having a quadrangular pyramid shape. The outer conductor 3 is formed by a taper portion formed so as to have a central conductor supporting rod 5 as an insulator and is insulated from the outer conductor 3 at the center of the inner space formed by the outer conductor 3. In this state, both ends thereof are formed by the central conductor 4 extending to the apex of the quadrangular pyramidal portion of the outer conductor 3. The high frequency signal source 1 and the coaxial load 10 are connected to both apexes of the TEM cell 11.

The high frequency signal source 1, the outer conductor 3 and the center conductor 4 are connected via a coaxial connector 2, in which case the outer conductor of the coaxial cable and the illustrated outer conductor 3 are connected to form a coaxial cable. Center conductor and illustrated center conductor 4
And are connected. Further, the coaxial load 10 connected to the other vertex is connected between the outer conductor 3 and the center conductor 4.

On the side surface of the test space formed by the outer conductor 3, the sample storage door 6, the input / output and power supply terminals 7 are provided.
The test sample 8 to be tested is provided in the test space formed between the test sample storage door 6 and the outer conductor 3 and the central conductor 4. It is set on the insulating base 9 for the sample. The DUT 8 receives input / output of necessary signals and supply of power through the input / output and power supply terminals 7 formed of through connectors.

In the prior art configured as described above, when a high frequency signal is applied from the high frequency signal source 1, this high frequency signal is uniformly distributed in the space defined by the outer conductor 3 and the central conductor 4 between them. An electromagnetic field is generated, propagates, and is absorbed by the coaxial load 10.

Therefore, the sample 8 set in the test space formed between the outer conductor 3 and the center conductor 4 is exposed to a uniform electromagnetic field having a predetermined arbitrary size. If the sample 8 is operated in this state, the above-described conventional technique can perform the above-described various tests on the sample 8.

Further, in the above-mentioned conventional technique, the high frequency signal source 1 is used.
To the intensity of the electromagnetic field generated from the DUT 8 by replacing
Electromagnetic radiation characteristics such as frequency distribution can be measured.

[0010]

In the above-mentioned prior art, there is reflection of a signal from the inner surface of the tapered portion of the outer conductor, resonance occurs in the test space, and this resonance promotes the growth of the multimode, and the test is performed. It is said that the uniformity of the electromagnetic field in the space is impaired, an electromagnetic field having a sufficiently high frequency cannot be uniformly generated in the test space, and the test of the sample 8 cannot be performed at a sufficiently high frequency. I have a problem.

Further, the above-mentioned prior art is extremely effective for use in a noise resistance characteristic test, an electric field strength calibration test, a sensitivity test, etc. of electronic equipment, but the center conductor 4 is formed by the outer conductor 3. Since it is located at the center of the internal space, the test space in which the sample 8 is set is only half of the space formed by the outer conductor 3 and the space utilization efficiency is low. Have Further, in the above-mentioned conventional technique, the coaxial load 10 serving as the connection end and the termination of the high frequency signal source 1 from the central portion of the outer conductor 3 for setting the sample 8 is used.
There is a problem that the taper portion formed toward the connection end of is long, which makes the device large.

That is, in the above-mentioned conventional technique, the device cannot be downsized even when the sample 8 is small, and when the sample 8 is large, the device itself becomes extremely large. There is a problem.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a TEM cell which is small in size, convenient in use, and can be used up to a sufficiently high frequency.

[0014]

According to the present invention, the object is to make the outer conductor have a substantially rectangular cross section at a position where a test space for setting a sample is formed, and both end surfaces of the outer conductor have a conical shape. Is formed with a tapered portion so that both side surfaces and the upper surface on the input end side have a conical shape, and the length of the tapered portion from the test space portion to the terminal end. Is formed so as to be shorter and asymmetrical than the length of the taper portion from the test space portion to the input end, and the center conductor is placed in the inner space surrounded by the outer conductor along the upper surface portion of the outer conductor, This is achieved by arranging the conductor so that it is not in contact with the conductor.

[0015]

In the present invention, since the outer conductor on the terminating side is tapered only on its side surface, the reflected wave from the inner surface of the tapered portion can be reduced as compared with the prior art. It is possible to prevent the occurrence of resonance in the space and the occurrence of multi-modes, and it is possible to use up to an extremely high frequency.

Further, according to the present invention, by providing the above-mentioned structure, the length from the input end to the terminal can be shortened, and further, the test space surrounded by the center conductor and the outer conductor can be enlarged. it can. The present invention makes it possible to perform a test on a larger sample as long as the device has the same size as that of the prior art, and also to test the sample of the same size as that of the conventional technology. If so, the entire device can be made compact.

Further, by appropriately providing the electromagnetic wave absorber on the inner surface of the outer conductor, it is possible to use even higher frequencies.

[0018]

An embodiment of a TEM cell according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a side view showing the construction of an embodiment of the present invention, and FIG. 2 is a plan view showing the construction of an embodiment of the present invention. In FIGS. 1 and 2, reference numeral 12 is a radio wave absorber, and other reference numerals are the same as those in FIG.

In the embodiment of the present invention shown in FIGS. 1 and 2, the outer conductor 3 and the center conductor 4 are connected to the high-frequency signal source 1, and the outer conductor 3 and the center conductor 4 are connected to the coaxial load 10. The configuration and the configuration of the peripheral portion including the sample storage door 6 provided on the side surface of the outer conductor are the same as those in the case of the conventional technique described with reference to FIG.

In the outer conductor 3 according to the embodiment of the present invention, on the input end side where the outer conductor 3 and the center conductor 4 are connected to the high frequency signal source 1, both side surfaces and the upper side surface of the outer conductor 3 have a high frequency. The test space portion is formed so as to spread from the position of the coaxial connector 2 connecting the signal source 1 toward the test space portion of the TEM cell 11 in a tapered shape, and the test space portion disposed substantially at the center of the TEM cell 11 has a predetermined size. The length portion is configured to have a substantially rectangular cross section.

Further, in the outer conductor 3, only the both side surfaces of the outer conductor 3 are connected to the coaxial load 10 in a tapered shape on the terminal side connected to the test space portion connecting the outer conductor 3 and the center conductor 4 to the coaxial load 10. It is configured to be narrowed toward the section. The length from the test space portion to the coaxial load 10 is smaller than the length from the coaxial connector 2 to the test space portion.

The center conductor 4 is arranged along the upper side surface of the outer conductor in the internal space formed by being surrounded by the outer conductor 3 having the above-described structure, and both ends thereof are respectively arranged in the high frequency signal source 1. And a coaxial load 10. As shown in FIG. 1, the central conductor 4 is located between the upper side surface of the outer conductor 3 and the lower outer conductor of the central conductor 4 at a position larger than the upper outer conductor. It is supported by the center conductor support rod 5 made of an insulator such as Teflon or Duracon.

The center conductor supporting rod 5 made of an insulator and provided between the upper surface of the outer conductor 3 and the lower surface of the outer conductor 3 supports the center conductor 4. Also, the outer conductor 3 and the center conductor 4
May be made of, for example, aluminum or copper.

According to such an embodiment of the present invention, a large test space can be formed by the lower part of the central conductor 4 and the lower surface and the side surface of the outer conductor 3, and an electromagnetic field is generated in this space. By setting the sample 8, the noise resistance characteristic test, the electric field strength calibration test, the sensitivity test of the sample 8, or the electromagnetic radiation characteristic test from the sample 8 can be performed.

In the above-described embodiment of the present invention, the cross sectional dimensions of the test space formed by the outer conductor 3 are 1800 mm wide × 2000 mm high, and the internal height of the test space is 11 mm.
When it was set to 00 mm, the electromagnetic field up to 1000 MHz could be uniformly distributed in the test space.

According to the embodiment of the present invention, the electromagnetic field strength distribution in the test space in which the sample 8 is set can be made uniform, and various reproducible and precise tests for the sample 8 are possible. It can be performed.

One embodiment of the present invention shown in FIGS. 1 and 2 is, at least, in order to make the above-mentioned electromagnetic field intensity distribution more uniform and to expand the usable frequency to a sufficiently high frequency. The electromagnetic wave absorber 12 is provided on the inner surface of the tapered portion of the outer conductor 3 formed on the terminal side. The radio wave absorber 12 is further appropriately arranged on other parts of the inner surface of the outer conductor 3, for example, the side surface of the test space portion, the bottom surface of the input end side taper portion, etc. to adjust the electrolytic strength distribution and to adjust the usable frequency. It can be adjusted to increase the upper limit or the like.

The electromagnetic wave absorber 12 is formed in a plate shape, a wave shape, or a pyramid shape, for example, by a ferrite type or carbon type electromagnetic wave absorber, and its size depends on the frequency of the input signal. It is selected appropriately.

The embodiment of the present invention is thus provided with the sample 8
It is possible to make the electromagnetic field strength distribution more uniform in the test space in which is set, and it is possible to perform various highly precise and precise tests for the sample 8.

Although the above-described embodiment of the present invention has been described as connecting the high-frequency signal source 1 to generate a high-frequency electromagnetic field in the test space, the present invention replaces the high-frequency signal source 1 with an interference. It can also be used to measure the electromagnetic radiation characteristics of the DUT placed in the test space by connecting a wave intensity measuring device, a spectrum analyzer, or the like.

According to the above-described embodiment of the present invention, the length from the input end to the end can be shortened, and the test space surrounded by the center conductor and the outer conductor can be increased. Further, according to one embodiment of the present invention, it is possible to test a larger test sample if the device has the same size as that of the prior art, and the test sample of the same size as that of the prior art is provided. If the product is to be tested, the entire device can be made compact.

Further, since the outer conductor on the terminal side is tapered only on its side surface, it is possible to reduce the reflected wave from the inner surface of the tapered portion as compared with the prior art. It is possible to prevent the occurrence of resonance and the occurrence of multi-modes and enable use up to an extremely high frequency.

[0034]

As described above, according to the present invention, it is possible to provide a TEM cell having a small size and a large effective space, and to perform a noise resistance characteristic test, an electric field strength calibration test, a sensitivity test, an electromagnetic radiation of an electronic device or the like. It is possible to perform characteristic tests and the like with high reproducibility and precision.

Further, the present invention is more effective when it is constructed in a large size for testing a large sample.

[Brief description of drawings]

FIG. 1 is a side view showing the configuration of an embodiment of the present invention.

FIG. 2 is a plan view showing the configuration of an embodiment of the present invention.

FIG. 3 is a perspective view showing a configuration of a TEM cell according to a conventional technique.

[Explanation of symbols]

 1 high-frequency signal source 2 coaxial connector 3 outer conductor 4 center conductor 5 center conductor support rod 6 sample housing door 7 input / output and power terminals 8 sample 9 sample insulator 10 coaxial load 11 TEM cell 12 radio wave Absorber

Claims (2)

[Claims] 1. A T including an outer conductor and a central conductor arranged in a space formed by the outer conductor.
In the EM cell, the outer conductor is formed into a substantially rectangular cross section at a position where a test space for setting a sample is formed, and both end surfaces of the outer conductor are formed with a tapered portion so as to have a conical shape. Both side surfaces on the end side and the upper surface are formed so as to have a conical shape, and the length of the taper portion from the test space portion to the terminal end is set to a taper from the test space portion to the input end. Formed to be shorter than the length of the part and asymmetrical,
A TEM cell, wherein the center conductor is arranged in an internal space surrounded by an outer conductor along an upper surface of the outer conductor so as not to contact the outer conductor. 2. The TEM cell according to claim 1, wherein an electromagnetic wave absorber is provided on the inner surface of the outer conductor forming the taper portion from the test space portion to the terminal end.