JPH08146063A - Apparatus and method for measuring electromagnetic noise - Google Patents

Abstract

PURPOSE: To measure noise from an object to be measured without requiring much time. CONSTITUTION: An antenna 3 for vertical polarization and an antenna 4 for horizontal polarization are mounted to the same traveling stand 5c, and a turntable 2b is rotated by one turn to measure the turntable angle where the values measured at each antenna by a measuring instrument 6a for vertical direction and a measuring instrument 6b for horizontal direction indicate the maximum values. Then, the turntable 2b is fixed at an angle where the measuring instrument 6a for vertical direction indicates the maximum value and the traveling stand 5c is moved up and down to obtain the maximum value of noise due to vertical polarization. Also, the turntable 2b is fixed at an angle where the measuring instrument 6b for horizontal direction indicates the maximum value and the traveling stand 5c is moved up and down to obtain the maximum value of noise due to horizontal polarization.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic noise measuring device for measuring a radiated electromagnetic field of a telecommunication device and the like and a measuring method thereof.

[0002]

2. Description of the Related Art Electric equipment may generate noise from the electric equipment, and if the noise occurs, it adversely affects a telecommunication device. Therefore, it is necessary to prevent the noise generated from the electric equipment from leaking to the outside as much as possible. For this purpose, it is necessary to investigate where and how much noise the electric equipment generates. Conventionally, this is measured separately for vertical polarization and horizontal polarization. In the case of horizontal polarization, the antenna is installed horizontally and fixed at a height of about 1 m, the turntable on which the DUT is placed is rotated once, and the turntable is fixed at the rotation angle at which the maximum value is detected. After that, the antenna is raised and fixed at the height where the maximum value is detected, and the noise at that time is measured. For vertically polarized waves, set the antenna vertically and measure in the same procedure as for horizontally polarized waves.

[0003]

However, in such a conventional method, it is necessary to measure for each vertical polarization or horizontal polarization, and it is necessary to measure over the entire necessary frequency range. Each time it was changed, it was necessary to measure vertically polarized waves and horizontally polarized waves, and each time it was necessary to change the antenna installation and rotate the turntable, which took a very long time. . There is also a problem that noise that changes with time during the measurement time cannot be accurately measured.

The present invention has been made in view of such a situation, and makes it possible to measure noise in a short time.

[0005]

In order to achieve such an object, the invention of claim 1 provides a turntable for rotating an object to be measured on a horizontal plane, a horizontal polarization antenna and a vertical polarization antenna. Mounting A movable table that moves up and down, a vertical polarization measuring instrument that measures the signal captured by the vertical polarization antenna, and a horizontal polarization measuring instrument that measures the signal captured by the horizontal polarization antenna It is equipped with. According to the invention of claim 2, when the electromagnetic noise is measured by the invention of claim 1, the electromagnetic noise measured by the measuring instrument for vertical polarization and the electromagnetic noise measured by the measuring instrument for horizontal polarization are rotated by rotating the turntable. Determine the rotation angle that indicates the maximum value for each, set the turntable to the angle that indicates the maximum value measured by the vertical polarization measuring instrument, and then move the moving table up and down to measure the vertical polarization measuring instrument. Find the height that shows the maximum value, and use the measured value as the maximum value of the electromagnetic noise of vertical polarization, set the turntable to the angle that shows the maximum value measured by the horizontal polarization measuring instrument, and then move the platform. Is moved up and down to obtain the height at which the horizontal polarization measuring instrument shows the maximum value, and the measured value at that time is taken as the maximum electromagnetic noise of the horizontal polarization. According to the invention of claim 3, in the invention of claim 2, the measurement is carried out after the measured value becomes stable. According to a fourth aspect of the present invention, in the second or third aspect of the invention, the influence of mounting the horizontally polarized antenna and the vertically polarized antenna on the same movable table is corrected.

[0006]

[Operation] The noise due to the vertically polarized antenna and the horizontally polarized antenna is continuously measured without attaching and detaching the antenna, and the noise due to the vertically polarized wave and the horizontally polarized wave is maximized by one turntable turn. The turntable angle indicating the value is measured. In addition, a vertical noise level change is also required by vertically moving the vertically polarized antenna and the horizontally polarized antenna. Further, the turntable is fixed at an angle showing the maximum value for each of the vertically polarized wave and the horizontally polarized wave, and the maximum noise value is obtained by changing the antenna height.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a view showing an embodiment of the present invention, in which an object to be measured 1 is mounted on an object mounting base 2c mounted on a turntable 2b which rotates parallel to the upper surface of a ground plane 2a. At this time, the mounting position of the DUT 1 is set to be near the center position of the turntable 2b. In addition, the antenna mount 5a is located on the upper surface of the ground plane 2a at a predetermined distance from the turntable 2b.
Is provided, and the pole 5b is vertically attached thereto.

A movable table 5c is attached so that it can move up and down along the pole 5b. The arm 5d is attached to, for example, the upper end of the moving table 5c, the vertically polarized antenna 3 is attached to the tip of the arm 5d, and the arm 5e is attached to the lower end of the moving table 5c.
Is attached, and the antenna 4 for horizontal polarization is attached to the tip of the arm 5e.

Turntable 2b and antenna mount 5a
Is controlled by the CPU 8, and control according to an instruction input from the keyboard 9, that is, the turntable 2b is rotationally controlled when necessary. The antenna mounting base 5a is configured so that the moving base 5c is moved up and down.

The vertical polarization antenna 3 is connected to the vertical polarization measuring instrument 6a, the horizontal polarization antenna 4 is connected to the horizontal polarization measuring instrument 6b, and the measurement result is passed through the interface circuit 7. It is supplied to the CPU 8.

In the apparatus constructed as described above, when the keyboard 9 is operated with the movable table 5c fixed at an appropriate position to instruct the turntable 2b on which the DUT 1 is placed to rotate once, the CPU 8 Supplies the instruction to the turntable 2b, so that the turntable 2b rotates. As a result, the DUT 1 rotates, and the relative position of the electromagnetic noise source and the antenna changes. Therefore, CPU8
Takes in the signals output from the vertical polarization measuring instrument 6a and the horizontal polarization measuring instrument 6b, and stores the angles of the turntable 2b at which the respective signal levels become maximum.

Next, for example, the turntable 2b is fixed at an angle at which the maximum electromagnetic noise in the horizontal polarization is measured, and the movable table 5c is moved up and down to measure the horizontal polarization measured by the horizontal polarization measuring instrument 6b. The height at which the electromagnetic noise is maximized is detected, and the moving table 5c is fixed there. And CPU
Reference numeral 8 stands by for a few seconds for the purpose of noise stabilization, and when the noise becomes stable, the output of the horizontal polarization measuring instrument 6b is captured.

Next, the turntable 2b is fixed at the angle at which the maximum electromagnetic noise in the vertically polarized wave is measured, the movable table 5c is moved up and down, and the vertically polarized electromagnetic wave measured by the vertically polarized wave measuring device 6a is measured. The height at which the noise is maximized is detected, and the movable table 5c is fixed there. Then, the CPU 8 waits for a few seconds to stabilize the noise, and when the noise becomes stable, captures the output of the horizontal polarization measuring instrument 6b.

By repeating the above procedure for the target frequency, the electromagnetic noise in the required frequency band can be measured for each of the vertical polarization component and the horizontal polarization component. In this case, since the vertically polarized antenna 3 and the horizontally polarized antenna 4 are attached to the same movable table 5c, mutual influences occur between the antennas. However, this influence is measured in advance and correction is performed. The effect can be virtually eliminated.

A problem with the conventional method is that it requires man-hours for attaching and detaching the antennas for vertical polarization and horizontal polarization, and that the antenna height is changed for each polarization. The noise was measured by rotating the turntable 2b according to its height. Since the measurement is performed every time the frequency changes, the number of steps for attaching and detaching the antenna and the number of steps for rotating the turntable and measuring the noise are enormous. In addition, each time the measurement was performed, it waited for a few seconds until the noise was stabilized, and then the measurement was performed, so that the cumulative value of the waiting time was very large. However, in the measurement by the apparatus of FIG. 1, it is not necessary to attach and detach the antenna at least, and the turntable 2b can be rotated only a few times, and quick measurement can be performed.

[0016]

As described above, according to the present invention, a vertically polarized antenna and a horizontally polarized antenna are attached to one movable table so that they can be moved up and down, and a turntable on which an object to be measured is placed is provided. Since the result measured by rotating is taken in, it is not necessary to install and remove the antenna, and the turntable rotates the horizontal polarization antenna up and down when measuring the rotation angle to obtain the maximum noise. At this time, the vertical polarization antenna needs to be moved up and down 3 times, and the waiting time for noise to stabilize is 3 times. Therefore, the measurement time is much shorter than the conventional method. As a result, even if the noise level changes with time, the measurement time is not as long as in the conventional one, so unless the level changes within the measurement time, An effect that can be measured in probability.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

[Explanation of symbols]

1 ... Object to be measured, 2a ... Ground plane, 2b ... Turntable, 2c ... Mounting base, 3 ... Vertical polarization antenna, 4
… Horizontally polarized antenna, 5a… Antenna mount, 5b…
Pole, 5c ... moving base, 5d and 5e ... arm, 6a
... horizontal polarization measuring instrument, 6b ... vertical polarization measuring instrument, 7 ... interface, 8 ... CPU, 9 ... keyboard.

Claims (4)

[Claims] 1. A turntable for rotating an object to be measured on a horizontal plane, a movable table on which an antenna for horizontal polarization and an antenna for vertical polarization are attached, and which is movable up and down, and captured by the antenna for vertical polarization. An electromagnetic noise measuring device comprising: a vertical polarization measuring instrument for measuring a signal; and a horizontal polarization measuring instrument for measuring a signal captured by the horizontal polarization antenna. 2. The electromagnetic noise measuring method for measuring electromagnetic noise by the apparatus according to claim 1, wherein the turntable is rotated and the electromagnetic noise measured by the vertical polarization measuring instrument and the horizontal polarization measuring instrument are measured. The rotation angle indicating the maximum value of each electromagnetic noise is obtained, the turntable is set to the angle indicating the maximum value measured by the vertical polarization measuring instrument, and then the movable table is moved up and down to measure the vertical polarization. The height of the instrument shows the maximum noise value and the measured value at that time is the electromagnetic noise maximum value of vertical polarization, and the turntable is set to the angle showing the maximum value measured by the vertical polarization measurement instrument. After that, the mobile table is moved up and down to obtain a height at which the horizontal polarization measuring instrument shows the maximum noise value, and the measured value at that time is set as the maximum electromagnetic noise of the horizontal polarization. Iz measurement method. 3. The electromagnetic noise measuring method according to claim 2, wherein the measurement is performed after the measured value becomes stable. 4. The electromagnetic noise measuring method according to claim 2, wherein the influence of mounting the horizontally polarized antenna and the vertically polarized antenna on the same movable table is corrected.