JPH05133989A - Electromagnetic resistance testing device - Google Patents

Abstract

PURPOSE:To enable a measurer to monitor a screen without movement at the time of testing the radiation filed resistance of a specimen which requires evaluation on a TV screen, CRT, etc. CONSTITUTION:The title device is constituted of a height-adjustable specimen fixing stage 2 for fixing a specimen, arm 3 extended in the horizontal direction from the center of the stage 2, and electromagnetic wave radiating antenna 4 fitted to the arm 3 directly or through an antenna support 5 extended in the vertical direction. The antenna 4 is fitted to the arm 3 or support 5 by means of an antenna fitting section 7. Since the arm 3 makes 360 deg. revolution in the horizontal direction around the center of the stage 2, the antenna 4 also makes a revolution at an angle of 360 deg. along the circumference of a circle with a radius equal to the distance between the center of the stage 2 and antenna 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a test apparatus for evaluating electromagnetic resistance of electronic equipment such as information equipment and communication equipment and equipment.

[0002]

2. Description of the Related Art As a method for testing electromagnetic resistance, a method of applying an interfering wave current or an interfering wave voltage to a power supply line or a communication line (for example, IE
C 801-4), a method in which a sharp charging probe is directly applied to the specimen to cause electrostatic discharge (for example, IEC
801-2), a method of irradiating a specimen with a radiation electromagnetic field (for example, MIL STD 461) and the like.

Of these, the method of irradiating a radiation electromagnetic field is
As shown in FIG. 6, an antenna 42 for electric field emission is installed at a position several meters away from the test piece 41 to generate a strong electromagnetic field, which is irradiated to the test piece 41 to cause abnormal operation of the test piece 41. Test whether a malfunction occurs.

Since it is necessary to irradiate electromagnetic waves from various directions for measurement, the test piece 41 is usually installed on the turntable 43, the antenna 42 is fixed, and the test piece is rotated 360 °. (“Improvement of uniformity of electromagnetic field distribution in radiated immunity test”, IEICE 2nd class workshop, EMC of electronic equipment and its countermeasure workshop, 1990, 11)
Month).

[0005]

By the way, the television, C
The screen disorder is one of the evaluation items of the electromagnetic immunity such as RT. However, in the above-described evaluation device, the orientation of the screen of the sample 41 changes according to the rotation of the turntable, so that the measurer constantly moves. I needed to monitor the screen.

Further, since the radiation electromagnetic field resistance test is performed by radiating a strong electromagnetic field, it is usually performed in a space that is electromagnetically shielded from the outside, such as a shield room or a radio wave semi-anechoic room.

At this time, the measurer who evaluates the screen has to stay in the above space and is therefore exposed to the strong electromagnetic field generated by the antenna, which is dangerous. Furthermore, in this test, the strength of the electromagnetic field applied to the specimen must be uniform over the entire specimen.

However, in a conventional test in a semi-anechoic chamber in which the floor surface is a ground plane such as a metal or wire mesh surface, the test piece 31 is directly fed from the antenna 32 as shown in FIG.
There is a drawback in that the electromagnetic field strength varies greatly in the height direction and the front-back direction of the test piece due to the interference between the direct wave 34 radiated to the ground and the indirect wave 35 reflected by the ground plane 33 which is the floor surface.

An object of the present invention is to provide an electromagnetic immunity test device capable of monitoring a screen without moving a measurer in a radiated electromagnetic field immunity test of a specimen requiring screen evaluation of a television, a CRT, etc. An object of the present invention is to provide an electromagnetic immunity test device in which fluctuations in the electromagnetic field intensity with which a test piece is irradiated are small even in a test in a place where a ground plane is a floor surface such as a sound room.

[0010]

In order to achieve the above object, in the electromagnetic resistance test apparatus of the present invention, there is provided an electromagnetic resistance test apparatus having a sample fixing base, an arm and an antenna, wherein the sample fixing The table is for mounting a sample, and the arm can rotate 360 ° in the horizontal direction about the axis of the fixed table. The antenna is directly attached to the arm or indirectly through the antenna column. Installed,
The test piece is irradiated with electromagnetic waves from all directions on a plane by rotating integrally with the arm.

Further, the arm and the antenna or the antenna column has a slide mechanism on the arm which is movable in the radial direction with the antenna or the antenna column centered on a fixed base, and the rotation radius of the antenna is It is variable.

Further, the antenna column has a slide mechanism for moving the antenna vertically, and the height of the antenna from the floor is variable.

Further, the arm is composed of a flat surface having a constant shape and area and extending in the horizontal direction, and a radio wave is formed on a surface of the flat surface facing the line connecting the fixed base and the antenna. The absorber is attached.

[0014]

Since the electromagnetic immunity testing device of the present invention has a structure in which the antenna for generating an electromagnetic field is rotated at a fixed distance around the sample, the sample is fixed in all directions on a plane. The specimen can be irradiated with electromagnetic waves. Therefore, when a TV, CRT, etc. is used as the sample, the orientation of the screen is always the same, and it is possible to evaluate the screen using a specific small window provided in a shielded room or an anechoic room. Is. As a result, the screen evaluation measurer can be evaluated while being outside the measurement room, and is not exposed to a strong electromagnetic field.

Further, if the structure of the arm connecting the table on which the sample is placed and the antenna for electromagnetic field emission is made a flat surface having a certain area and shape with a horizontal spread, and the electromagnetic wave absorber is mounted on the flat surface. Since the ground plane that causes indirect waves can be covered with the electromagnetic wave absorber described above, the electromagnetic waves applied to the test piece are only direct waves, eliminating the non-uniformity of electromagnetic field strength caused by interference with indirect waves. To be done.

The flat surface and the area for mounting the electromagnetic wave absorber should be as large as possible, and at least the first Fresnel zone of the straight line connecting the sample fixing base and the antenna (for example, Modern Electromagnetic Engineering, p219, Amemiya, Ohmsha) , Tokyo, January 1985).

[0017]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a diagram showing an electromagnetic resistance test apparatus 1 for a radiated electromagnetic wave according to a first embodiment of the present invention. The test apparatus 1 is attached to the sample fixing base 2 on which the sample is placed, the arm 3 extending horizontally with the fixing base 2 as a center, directly on the arm 3, or via an antenna support 5 extending vertically. The electromagnetic wave radiation antenna 4 is provided.

The arm 3 and the antenna 4 or the antenna column 5 and the antenna 4 are attached via an antenna attaching portion 7. Since the arm 3 rotates 360 ° in the horizontal direction around the fixed base 2, the antenna 4 has a radius of 3 mm from the center of the fixed base 2 to the antenna 4.
Rotate 60 °.

Since the directivity of the antenna 4 is set to face the center of rotation, the radiated electromagnetic field is always radiated to the sample regardless of its position on the circumference.

The height of the fixed base 2 is variable, and the height at which the specimen is installed can be changed. The antenna is selected in consideration of measurement conditions such as measurement frequency band and directivity.

The antenna support column 5 and the arm 3 are provided with a mechanism 6 capable of sliding the antenna support column 5 on the arm 3 in the horizontal direction along the lengthwise direction, whereby the turning radius of the antenna 4 can be made variable. .. Further, the height of the antenna 4 can be made variable by providing a vertical sliding mechanism 8 on the antenna mounting portion 7 and the antenna support column 5.

Between the arm 3 and the floor surface, one or more casters 9 or bearings oriented in the circumferential direction are provided to smooth the rotation of the arm 3 and at the same time.
It prevents the bending of.

The arm 3 does not necessarily have to be on the floor side, and as shown in the sectional view of FIG. The strut 5 may be suspended from the upper end of the arm 3 extending horizontally from the upper end of the antenna 3, and the antenna 4 may be hung down. As shown in the sectional view of FIG. The arm 3 that rotates around the shaft 12 provided in the above may be horizontally attached.

In any case, a polymer material which has little influence on the electromagnetic field is used for the construction of the device.

FIG. 4 is a diagram showing an electromagnetic immunity test device 21 according to a second embodiment of the present invention. Main test equipment 21
Is a specimen holder 22 for holding the specimen, and the holder 22.
Is composed of a plate-shaped arm 23 extending horizontally with respect to the center, and an electromagnetic wave radiation antenna 24 attached directly to the plate-shaped arm 23 or via an antenna support 25.

The plate-like arm 23 is rotatable about the sample base 22 by 360 ° and has an elliptical shape including a first Fresnel zone formed by a line connecting the antenna 24 and the base 22. A broadband electromagnetic wave absorber 26 is attached to the upper plane of the plate-like arm 23 to radiate an electromagnetic wave arm 23.
Also, reflection on the floor surface 27 of the measurement room can be suppressed.

[0027]

According to the electromagnetic resistance test apparatus of the present invention, in a resistance evaluation test against a radiated electromagnetic field such as a television and a CRT, the screen evaluation measurer can monitor the screen without moving. In addition to shortening the measurement time, it is possible to monitor from the outside of the measurement room, so that the measurer is not exposed to a strong electromagnetic field, and a safe electromagnetic resistance test can be performed.

Further, according to the electromagnetic immunity test apparatus of the present invention, the influence of the reflected wave on the floor can be removed even in a measurement place where the floor is composed of a ground plane such as a semi-anechoic chamber. In addition, the strength of the electromagnetic field in the space where the test piece is installed becomes uniform, which has the effect of enabling an accurate electromagnetic resistance test.

[Brief description of drawings]

FIG. 1 is a diagram showing a basic form of a radiation electromagnetic immunity test apparatus according to the present invention.

FIG. 2 is a sectional view showing a radiation electromagnetic immunity test apparatus according to the present invention.

FIG. 3 is a sectional view showing another embodiment of the radiated electromagnetic immunity test apparatus according to the present invention.

FIG. 4 is a diagram showing an example of an electromagnetic immunity test apparatus having a structure for making the irradiation electromagnetic field strength uniform according to the present invention.

FIG. 5 is a principle view showing that the irradiation electromagnetic field strength becomes non-uniform in the electromagnetic resistance test.

FIG. 6 is a diagram showing a radiated electromagnetic immunity test apparatus according to the prior art.

[Explanation of symbols]

 1 Electromagnetic Immunity Test Device 2 Specimen Fixture Base 3 Arm 4 Electromagnetic Wave Emission Antenna 5 Antenna Prop 6 Antenna Prop Slide Mechanism 7 Antenna Mounting Part 8 Antenna Sliding Mechanism 9 Caster 11 Post 12 Axis 13 Measurement Room Ceiling 21 Electromagnetic Resistance Test Device 22 Providing Specimen fixing base 23 Plate-like arm 24 Electromagnetic radiation antenna 25 Antenna support 26 Electromagnetic wave absorber 27 Measurement room floor

Claims (4)

[Claims] 1. An electromagnetic immunity test device having a specimen fixing base, an arm, and an antenna, wherein the specimen fixing base is for mounting a specimen, and the arm is an axial center of the fixing base. 360 around the center
° It is rotatable, and the antenna is attached directly to the arm or indirectly through the antenna support, and rotates integrally with the arm to irradiate the sample with electromagnetic waves from all directions on the plane. Electromagnetic immunity test equipment. 2. The arm and the antenna or the antenna column has a slide mechanism on the arm, which is movable in the radial direction around the fixed base of the antenna or the antenna column, and has a rotation radius of the antenna. The electromagnetic immunity test apparatus according to claim 1, wherein the electromagnetic resistance test apparatus is variable. 3. The antenna column has a slide mechanism for moving the antenna vertically, and the height of the antenna from the floor is variable. 2. The electromagnetic resistance test apparatus according to 2. 4. The arm is formed of a flat surface having a constant shape and area and extending in the horizontal direction, and on the surface of the flat surface facing the line connecting the fixed base and the antenna,
A radio wave absorber is attached to the radio wave absorber.
Electromagnetic immunity test device according to.