FR2801983A1 - Support for radiation detecting aerial includes three adjustable perpendicular arms made of non-magnetic material such as wood - Google Patents

Abstract

The structure provides full adjustment of the aerial position without perturbing the magnetic fields in the vicinity. The support for an aerial (10) for measuring the susceptibility or the radiation from electronic equipment (18) includes a first fixed arm (11) forming the X-axis of the structure. A second arm (12) forms the Y-axis which lies perpendicular to the first and able to move w.r.t. the first axis. A third arm (13) is carried by the second arm and is mobile w.r.t. this second arm. On its remote end this third arm carries the support (14) for the aerial (16). The support arms are made from a non-magnetic material, such as wood, to enable the aerial to be placed in any chosen position w.r.t. the three co-ordinate axes (X, Y, Z). Each arm may have a graduation (Rx, Ry, Rz) for measurement of the position of the aerial support.

Description

The present invention relates to an antenna support device. More particularly, the device according to the invention makes it possible to carry out measurements of electromagnetic susceptibility and I or of radiated emissions, on an electronic device in operation.

In the automotive field, more and more electronic devices are used in the vehicle. It may be internal vehicle devices such as an injection or ignition computer, a car radio, etc.

but also devices temporarily present in this vehicle such as a mobile phone, video games etc ...

The proximity of all these devices can adversely affect the proper functioning of one or the other, or even in certain cases, create critical conditions in the driving of the vehicle, for example, alterations of the motor control signals, brake or air (airbag).

As a result, the electromagnetic radiation emitted by each of these devices is controlled. To do this, the electronic device is placed in an anechoic chamber in which no disturbing electromagnetic field prevails.

The electronic device to be tested is then put into operation and measurements of the radiation emitted by this device are carried out. These measurements are made using specific antennas positioned at predetermined points relative to the device to be tested.

These measurements must be made in exactly the same way for all the devices to be tested.

Until now, these measurements are made by placing the electronic devices to be tested on a table and moving around them one (or more) specific antennas. These antennas are held in place during the measurement, using tripods. Unfortunately very often, the stability of a tripod is not very rigorous (especially when wearing a poorly balanced antenna). As a result, the tripod often falls off and, furthermore, the repeatability of the measurements leaves something to be desired because the position of the antenna is not precisely determined. Moreover, the time of setting up the antennas on their tripods and too important and the positioning of the tripod (with its antenna) relative to the device to be tested is difficult to achieve.

The object of the present invention is to provide an antenna support device for performing susceptibility and radiation tests emitted by electronic devices not having the disadvantages mentioned above. Namely, one seeks in particular to obtain a good repeatability "measurements and a good accuracy of the position of the antenna with respect to the device tested.

For this purpose, the present invention relates to an antenna support device for measuring susceptibilities and I or emissions radiated by electronic equipment, said device being characterized in that it comprises: a first fixed arm embodying an axis; abscissa, - a second arm materializing an ordinate axis, perpendicular to the first arm, the second arm being movable relative to the first and a third arm carried by the second arm and movable relative thereto, third arm being perpendicular to the first and second arms carrying at its end remote from these arms a support means for an antenna, all of these arms and support being made of a-magnetic material and being adapted to place the antenna in a predetermined position marked with respect to the three axes.

Thanks to such a support device, the antenna can be placed at a determined point in space with respect to the device to be tested. The support according to the invention makes it possible, in fact, to accurately locate the position of the antenna (along three perpendicular axes). This makes it possible to repeat the same type of measurement with several different antennas very quickly (it is indeed enough to change the antenna without moving the support).

Advantageously, the entire support device is made of a-magnetic material (eg wood) so as not to create disturbing fields at the time of the test.

Advantageously, the height adjustment of the antennas is performed directly by the height of the antenna foot introduced into the support.

Other objects, features and advantages of the present invention will become apparent from the following description, by way of non-limiting example, with reference to the accompanying drawings in which - <B> Figure 1 </ B> illustrates schematic the displacement of each support device arm according to the invention and - <B> Figure 2 </ B> is schematic perspective view of an antenna support according to the invention.

According to the embodiment shown in Figures 1 and 2, the support device 10 according to the invention comprises - a first arm 11 embodying an abscissa axis X, - a second arm 12 embodying an ordinate axis Y, and - a third arm 13 embodying an axis of height Z.

Each of these arms is perpendicular to the other two, so that a three-dimensional orthogonal reference is made.

The second arm is movable relative to the first and slides along the latter opposite a graduated mark Rx.

The third arm is movable relative to the second and slides along it facing a graduated mark Ry.

The third arm 13 carries a recess 14 at its end remote from the second arm. This recess 14 is adapted to receive the foot 15 of an antenna 16 and constitutes a support means for this antenna.

The height adjustment of the antenna is carried out by blocking the foot 15 of the antenna at the desired height, in the recess 14 by means of a pin 17. This pin 17 is inserted into a hole pierced in the arm 13 and positions the antenna 16 according to a predetermined number of heights. In the example shown, there are three possibilities of height Rz for the antenna. Of course, this number may be different if necessary.

In addition, it is possible to have a set of antennas having feet of different heights in order to perform all the necessary measurements. Advantageously, this plurality of antennas can be arranged on a removable carriage provided with appropriate support means.

The use of the device according to the invention is simple. A test electronic device 18 is placed on a test table 19 fixed with respect to the first arm 11. This device is put into operation. Radiation measurements emitted by the device 18 are made by moving the antenna 16 in the vicinity of the device.

The details of the measurements made will not be described here, they are known and standardized procedures. These procedures require performing, on the same device to be tested 18, several measurement series with different antennas (transceiver) using test devices 20 simulating the vehicle. These antennas must be rigorously placed at the same points relative to the device to be tested, whether in transmission or reception. During these tests, the radiation emitted by the cable harness connecting the device to be tested and the simulation devices 20 of the vehicle is measured.

The device according to the invention makes it possible to very quickly place any antenna at a given point with respect to the test device. The repeatability of measurements and their accuracy is thus ensured with great speed. It will be noted that the markers Rx Ry and Rz are graduated markers.

Note that in the example shown the entire device is made of wood. This makes it possible not to disturb the measurements made. Indeed, this material has a low reflection, it insulates and has a low electrical permittivity. However, the device according to the invention could equally well be made of plastic or any other a-magnetic material.

It should be noted that one of the advantages of the present invention lies in the time saving achieved by using the antenna support according to the invention compared to what was necessary before. Thus, measurements made with the device according to the present invention are more accurate, faster and repeatable.

Of course, the present invention is not limited to the embodiment described above and encompasses any variant within the reach of ordinary skill in the art. Thus, the arm 13 may also include a sliding element carrying the foot of an antenna. This sliding element being adapted to be moved along the arm 13 opposite a graduated mark Rz.

Claims (6)

<B> <U> CLAIMS </ U> </ B> Antenna support device (10) for the measurement of susceptibilities and I or emissions radiated by electronic equipment (18), said device being characterized in that it comprises - a fixed first arm (11) materializing an abscissa axis (X), a second arm (12) embodying an ordinate axis (Y), perpendicular to the first arm, the second arm movable relative to the first (11) and a third arm (13). ) carried by the second arm and movable relative thereto, the third arm being perpendicular to the first and second arms and carrying at its end remote from these arms a support means (14) for an antenna (16), the all of these arms (11, 12, 13) and support (14) being made of a magnetic material and being adapted to place the antenna (16) in a predetermined position marked with respect to the three axes (X, Y, Z) . 2. Device according to claim 1, characterized in that each arm (11, 12, 13) carries a graduation (Rx, Ry, Rz). 3. Device according to claim 1 or 2, characterized in that it further comprises a test table (19) secured to the first arm (1) and fixed in space, this table being adapted to support a device electronic test (18). 4. Device according to any one of the preceding claims, characterized in that the support (14) is adapted to receive an antenna (16) of predetermined height. 5. Device according to any one of the preceding claims characterized in that it further comprises a movable carriage adapted to support a plurality of antennas (16) of predetermined distinct heights. 6. Device according to any one of the preceding claims characterized in that it is made of wood.