Electromagnetic stirrer, electromagnetic measuring system, assembly method and associated measuring method

Abstract

Electromagnetic stirrer, electromagnetic measuring system, assembly method and associated measuring method This electromagnetic stirrer (26) comprises: - a mat (40); and - at least one blade (42A to 42C) having a surface reflecting radio waves and / or microwaves, the blade (42A to 42C) having at least two non-coplanar regions. The mat (40) has a blade attachment zone (44), the blade (42A to 42C) being attached to the blade attachment zone (44). At least a portion of the mat (40) and / or of the or each blade (42A to 42C) is inflatable. Figure for abstract: figure 1

Description

Title of the invention: Electromagnetic stirrer, electromagnetic measuring system, mounting method and associated measuring method

[0001] The present invention relates to an electromagnetic stirrer, comprising:

[0002] - a matt;

[0003] - at least one blade having a surface reflecting radio and / or micro waves wave, the blade having at least two non-coplanar regions;

[0004] the mast having a blade attachment area, the blade being attached to the blade attachment area.

[0005] Such a mixer is intended in particular to be mounted in a reverberation chamber, during tests of exposure of equipment to electromagnetic fields.

[0006] Such tests are intended to measure the electromagnetic field transmitted to equipment on a platform, in particular equipment on an aircraft, a satellite, a land or naval vehicle. The equipment is, for example, a computer bay housed in a hold of the platform.

[0007] Alternatively, the tests are intended to verify the proper functioning of equipment on a platform in the presence of a high-intensity electromagnetic field.

[0008] In particular, the mixer is suitable for being rotated around an axis of rotation between successive measurements of the electromagnetic field received in the vicinity of the equipment or in it, from an electromagnetic field emitted in the reverberation chamber.

[0009] The equipment present in an aircraft must be protected from external electromagnetic fields to which the aircraft is subjected. In this respect, the penetration of the electromagnetic field into the aircraft, in the vicinity of the equipment it contains, must be measured precisely during the qualification and certification of an aircraft. Indeed, it is important that this equipment, in particular electronic equipment, is well protected against external electromagnetic fields so as not to cause disturbances during operation.

[0010] To carry out these tests, a known method consists of placing the aircraft outside, for example on a tarmac, and mounting antennas outside the aircraft which make it possible to illuminate the aircraft according to different incidences, polarizations and at different frequencies.

[0011] The penetration of the electromagnetic field into the holds containing the equipment is measured by receivers placed in the aircraft.

[0012] Such a method is tedious to implement, and requires favorable weather conditions.

[0013] An alternative method is to measure the effect of the electromagnetic field in a reverberant environment using high intensity radiated field (HIRF) type testing. In this type of testing, the platform containing the equipment to be tested is placed in a reverberation chamber having walls reflecting the electromagnetic field. The transmitter and the mixer are also placed in the chamber. Measurements of the electromagnetic field received in the platform in the vicinity of the equipment are carried out at different angular values of the mixer around a vertical axis, which changes the boundary conditions of the reverberation chamber and therefore shifts the spatial distribution of the resonance modes within the chamber.

[0014] A known mixer comprises a central metal mast, and metal blades permanently fixed on the central mast. The blades are angularly offset from each other, and often comprise at least two non-coplanar surfaces.

[0015] Such a mixer is not entirely satisfactory. Indeed, to be effective, such a mixer must have a height close to the smallest dimension of the reverberation chamber.

[0016] For large volume chambers, which can contain for example a complete aircraft, the mixer is bulky, heavy and difficult to dismantle. It is difficult to transport and the tests must therefore always be carried out in the same chamber, by bringing the aircraft into this chamber, which can be expensive.

[0017] Furthermore, such a brewer requires a large amount of space for storage. Furthermore, its dimensions and shape are fixed when the brewer is designed, so that a particular brewer is only really suitable for a given chamber.

[0018] Such a brewer is also generally quite fragile, which requires specific means and skills to handle and repair it. It has often aggressive metal edges which can create risks of injury when handling it.

[0019] An aim of the invention is to provide a particularly effective electromagnetic stirrer for enabling measurements in a reverberation chamber by generating a homogeneous and isotropic electromagnetic field, the electromagnetic stirrer being simple to handle and modular.

[0020] To this end, the invention relates to an electromagnetic stirrer of the aforementioned type, characterized in that at least part of the mast and / or of the or each blade is inflatable.

[0021] The electromagnetic stirrer according to the invention may comprise one or more of the following characteristics, taken in isolation or in any technically possible combination:

[0022] - the or each blade is inflatable;

[0023] - it includes a removable fixing system for the or each blade on the area of blade attachment;

[0024] - the fastening system comprises a zipper;

[0025] - the or each blade has a lateral edge, the or each blade being fixed along its lateral edge on the blade attachment area;

[0026] - it comprises a plurality of inflatable blades having different dimensions, the blade attachment area being suitable for interchangeably accommodating several blades of the plurality of inflatable blades, each blade being suitable for being mounted as a replacement for another blade on the blade attachment area;

[0027] - the inflatable blade has at least one region having a C-shaped section, for example example a single region having a C-shaped section, or a plurality of regions having a C-shaped section arranged adjacent to each other;

[0028] - the inflatable blade comprises an inflatable frame and at least one layer reflecting the electromagnetic radio and / or microwave waves carried by the inflatable frame;

[0029] - the frame comprises at least two inflatable peripheral uprights and at least an inflatable crosspiece connecting the inflatable peripheral uprights together;

[0030] - the mast is inflatable;

[0031] - the mast is cylindrical with a vertical axis, the blade attachment zone extending along of a mast generator;

[0032] - it comprises a rotating plate, the mast carrying the or each blade being suitable for being mounted on the turntable to be rotated around a vertical axis by the turntable.

[0033] The invention also relates to an electromagnetic measuring and / or testing system comprising:

[0034] - a reverberation chamber;

[0035] - a transmitter of radio and / or microwave electromagnetic waves intended to be placed in the reverberation chamber;

[0036] - possibly an electromagnetic wave receiver intended to be placed at the proximity of equipment placed in the reverberation chamber; and

[0037] -an electromagnetic mixer as defined above, intended to be placed in the reverberation chamber.

[0038] The invention also relates to a method of mounting an electromagnetic stirrer, comprising the following steps:

[0039] - provision of a mast and at least one blade having a reflective surface radio waves and / or microwaves, the blade having at least two non-coplanar regions;

[0040] the mast having a blade attachment zone, the blade being attached to the blade attachment zone, at least a portion of the mast and / or of the or each blade being inflatable;

[0041] the inflatable part of the mast and / or of the or each blade being initially deflated, the method comprising a step of inflating the inflatable part of the mast and / or of the or each blade.

[0042] The mounting method according to the invention may comprise the following characteristic:

[0043] the mast and / or the or each blade is inflatable, the providing step comprising providing the mast and / or the or each blade in a deflated and disassembled configuration, the method comprising assembling the or each blade on the mast before inflation, and inflating the mast and / or the or each blade after assembly.

[0044] The invention also relates to a method for measuring and / or testing electromagnetically comprising the following steps:

[0045] - provision of a reverberation chamber:

[0046] - implementation of a method for mounting an electromagnetic stirrer and arrangement of the electromagnetic mixer in the reverberation chamber;

[0047] - arrangement of an emitter in the reflecting chamber, and;

[0048] - emission by the transmitter of radio and / or microwave electromagnetic waves in the reverberation chamber;

[0049] - installation of a receiver in the reverberation chamber in the vicinity of equipment to be tested in the reverberation chamber and measurements of the electromagnetic field received by the receiver, or / and

[0050] testing of equipment in operation in the reverberation chamber;

[0051] the method comprising a step of rotating the electromagnetic stirrer around an axis of rotation between two successive measurements of the electromagnetic field received by the receiver or between two successive tests of the equipment in operation.

[0052] The invention will be better understood on reading the following description, given solely by way of example, and made with reference to the appended drawings, in which:

[0053] - [Fig.l] [Fig.l] is a schematic view of a first measuring system or / and of electromagnetic test according to the invention, comprising an inflatable electromagnetic stirrer arranged in a reverberation chamber;

[0054] - [Fig.2] [Fig.2] is a schematic view of the inflatable parts of the brewer including the mast and a blade;

[0055] - [Fig.3] [Fig.3] is a schematic side view of sections of different blades which can be mounted interchangeably on the brewer's mast of [Fig.2];

[0056] - [Fig.4] [Fig.4] is a curve illustrating the standard deviation on the values of the three components of the electromagnetic field in the reverberation chamber after a complete rotation of the mixer in the chamber.

[0057] [Fig. 1] illustrates a first electromagnetic measurement and / or testing system 10, intended to generate an electromagnetic field and to measure the electromagnetic field received by a piece of equipment 12 arranged within a platform 14 is illustrated in [Fig. 1] and / or to test the operating performance of the piece of equipment 12 in the presence of the received electromagnetic field (in particular when the emitted electromagnetic field has a high intensity, in particular between a few V / m and a few kV / m, for example 100 V / m, “High Intensity Radiated Field” or HIRF).

[0058] The measuring system 10 is intended in particular to test the protection of the equipment 12 provided by the platform 14 with respect to the received electromagnetic field, and / or the performance of the equipment 12 and more generally of the platform 14 in operation when the platform 14 including its equipment 12 is subjected to this electromagnetic field.

[0059] In a particular case, the measuring system 10 is intended to measure the transfer function of the electromagnetic field as a function of the frequency through the walls of the platform 14, and possibly through electromagnetic protection barriers provided within the platform 14, in particular in a hold of the platform 14.

[0060] The equipment 12 is for example a computer, a sensor, a computer bay or any on-board aeronautical equipment, arranged in the platform 14. The platform 14 is in particular an aircraft, in particular a civil or military aircraft, in particular an airplane or a drone.

[0061] With reference to [Fig.l], the measuring system 10 comprises a reverberation chamber 20 inside which the measurements are carried out.

[0062] The measuring system 10 also comprises an electromagnetic field transmitter 22 arranged in the reverberation chamber 20, outside the platform 14 and at least one electromagnetic field receiver 24 arranged in the vicinity or in the equipment 12, within the platform 14.

[0063] The measuring system 10 further comprises an electromagnetic stirrer 26 according to the invention, arranged in the reverberation chamber 20, the electromagnetic stirrer 26 being at least partially inflatable.

[0064] The mixer 26 is intended to be pivoted around a vertical axis A-A' between two electromagnetic field measurements to modify the boundary conditions of the reverberation chamber 20, and homogenize the average of the electromagnetic field and its maximum value at all points of the reverberation chamber 20 and rotate the electromagnetic field according to all polarizations.

[0065] The reverberation chamber 20 defines an interior volume 28 capable of containing the platform 14 receiving the equipment 12.

[0066] The interior volume 28 is for example greater than 1 m3 and in particular between 2 m3 and 10000 m3, in particular between 1000 m3 and 5000 m3 for example 3000 m3.

[0067] The reverberation chamber 20 is for example a fixed chamber arranged within a building, in particular a hangar, delimited by reflective surfaces 30.

[0068] Alternatively, the reverberant chamber 20 is a removable chamber, preferably inflatable. In this case, it comprises inflatable pillars and beams connecting the pillars, the pillars and beams supporting reflective surfaces 30 delimiting the interior volume 28.

[0069] The reflective surfaces 30 are capable of reflecting the electromagnetic field at least partially in the range of wavelengths of emission of this electromagnetic field by the transmitter 22 which will be specified below.

[0070] The reflective surfaces 30 are for example metallic surfaces, in particular formed by a metallic layer arranged on a deformable support, in particular a film, for example made of plastic or a fabric. The reflective surfaces 30 are attached to the pillars and beams of the reverberation chamber 20. By deformable, it is meant in particular that the support can be folded by hand by a user.

[0071] The transmitter 22 comprises at least one antenna capable of emitting an electromagnetic field at a frequency in the radio wave and / or microwave domain.

[0072] The frequency of the emitted electromagnetic field is for example between 10 kHz and 40 GHz, preferably between 100 MHz and 18 GHz for the example presented. Such a frequency range covers a large part of the electromagnetic fields to which an aircraft is subjected when it is moving on the ground or in flight.

[0073] Each receiver 24 is suitable for being arranged in the vicinity of or in the equipment 12 within the platform 14 to measure the electromagnetic field experienced by the equipment 12.

[0074] Each receiver 24 is for example arranged in a hold of the platform 14.

[0075] When the platform 14 is an aircraft, the hold is in particular a technical hold containing the electrical equipment and the computers of the aircraft. The technical hold is for example provided with electromagnetic protection barriers.

[0076] The receiver 24 is capable of measuring the intensity, frequency and / or phase of the electromagnetic field received through the platform 14 in the vicinity or in the equipment 12 to allow the calculation of a transfer function between the field emitted by the transmitter 22 and the field received by the receiver 24.

[0077] As indicated previously, the electromagnetic stirrer 26 is capable of allowing, by successive rotations around its axis A-A', the creation of a homogeneous and isotropic electromagnetic field at all points of the interior volume 28 of the reverberation chamber 20.

[0078] The electromagnetic stirrer 26 is here at least partially inflatable. In this example, it comprises an inflatable mast 40, at least one inflatable blade 42A to 42E, mounted in a removable and interchangeable manner on at least one fixing zone 44 of the mast and a system 46 for removable fixing of each blade 42A to 42E on the fixing zone of the mast 44.

[0079] Alternatively, the mast 40 is not inflatable, only the blades 42A to 42E are inflatable.

[0080] The electromagnetic stirrer 26 further comprises a system 48 for driving in rotation around the vertical axis A-A' the inflatable parts of the electromagnetic stirrer 26, these inflatable parts comprising the mast 40 and the or each blade 42A to 42C carried by the mast 40.

[0081] In the example shown in [Fig.l], the inflatable parts of the electromagnetic stirrer 26 are shown in an inflated and assembled configuration, the inflatable mast 40 being assembled on the rotation drive system 48.

[0082] The inflatable parts of the electromagnetic stirrer 26 are capable of passing into a deflated and disassembled configuration, in which the inflatable parts of the electromagnetic stirrer 26, here including the mast 40 and each blade 42A to 42B, are deflated and folded, thus occupying a minimal volume.

[0083] Thus, the electromagnetic stirrer 26 further advantageously comprises a bag 50 intended to receive the inflatable parts of the electromagnetic stirrer 26 in their deflated configuration. The volume occupied by the inflatable parts of the electromagnetic stirrer 26 in their deflated configuration is less than 1 m3, allowing them to be easily transported in the bag 50.

[0084] With reference to [Fig.2], the mast 40 is here formed from a cylindrical pillar 52 with vertical axis A-A'.

[0085] The pillar 52 defines several fixing zones 44 spaced angularly around the axis A-A', each fixing zone 44 extending substantially along a separate generatrix of the cylindrical pillar 52.

[0086] In the inflated configuration, the height of the pillar 52 is for example greater than 50 cm, and in particular between 1 m and 10 m. The diameter of the pillar is for example greater than 10 cm, and is in particular between 20 cm and 1 meter.

[0087] The pillar 52 is advantageously formed from at least one inflatable bladder having a sealed wall. The interior volume of the pillar 52 is capable of being inflated to a pressure greater than atmospheric pressure, for example by an air compressor 54.

[0088] In the example shown in Figures 1 and 3, the inflatable mixer 26 comprises a plurality of inflatable blades 42A to 42E, suitable for being mounted on a fixing zone 44 of the inflatable mast 40, in an interchangeable manner.

[0089] The blades 42A to 42E have different geometries, in particular different heights, and / or different curvatures.

[0090] Each blade 42A to 42E is non-planar. It thus has at least two non-coplanar regions.

[0091] In the example shown in Figures 1 to 3, each blade 42A to 42E has the shape of a section of cylinder cut along a plane parallel to the axis B-B' of the cylinder.

[0092] Each blade 42A to 42E thus has at least one region 60 of C-shaped section, taken perpendicular to the axis of the cylinder.

[0093] At least one blade 42A has two regions 60 of C-shaped section adjacent to each other, here mounted on each other by a common edge.

[0094] In the example shown in [Fig.3], the lengths L of the blades 42A to 42E taken horizontally between their apexes 62, and their free edges 64A, 64B are substantially equal. The length of each blade 42A to 42E is for example between 1 m and 3 m, for example equal to 2 m.

[0095] The width 1 of each blade 42A to 42E (see [Fig.2]), taken along the axis B-B' of the cylinder, is for example between 0.2 m and 5 m, for example equal to 3 m.

[0096] The height H of each blade 42A to 42E, taken vertically between the free edges 64A, 64B depends on the radius of curvature of the C-shaped section of each blade 42A to 42E. The radius of curvature of the C-shaped section is for example greater than 0.5 m, and is in particular between 2 m and 10 m, in particular between 2 m and 6 m.

[0097] In this example, as illustrated in [Fig.2], each blade 42B comprises an inflatable frame 70, and at least one reflective surface 72 carried by the inflatable frame 70.

[0098] The inflatable frame 70 comprises at least one inflatable bladder, preferably a plurality of inflatable bladders, delimiting lateral uprights 74A, 74B, and at least one crosspiece 76A, 76B. The uprights 74A, 74B and the crosspieces 76A, 76B define the periphery of the blade 42B and a central space.

[0099] The inflatable frame 70 further advantageously comprises at least one auxiliary crosspiece 78A, 78B, preferably a plurality of auxiliary crosspieces 78A, 78B connecting the uprights 74A, 74B through the central space.

[0100] The or each bladder is formed by a sealed pocket, suitable for being inflated to a pressure greater than atmospheric pressure, for example by the air compressor 54.

[0101] The reflecting surface 72 is capable of reflecting the electromagnetic field at least partially in the range of wavelengths of emission of this electromagnetic field by the transmitter 22. Thus, the reflecting surface 72 is capable of reflecting at least partially the radio and / or microwave electromagnetic waves emitted by the transmitter 22, or reflected by the platform 14 and / or by the equipment 12.

[0102] The reflective surface 72 is for example a metallic surface, in particular formed by a metallic layer arranged on a deformable support, in particular a film, for example made of plastic or a fabric. The reflective surface 72 is attached to the inflatable frame 70.

[0103] Preferably, the reflective surface 72 completely covers at least one main face of the blade 42B between the uprights 74A, 74B and the crosspieces 76A, 76B, here the rear main face. Advantageously, at least one other reflective surface 72 covers a front main face of the blade 42B.

[0104] In this example, each crosspiece 76A, 76B has a C shape. At least one crosspiece 76A, 76B laterally defines a complementary zone 78 for attachment to the mast, intended to be assembled in a removable manner on the attachment zone 44 of the mast 40.

[0105] The complementary fixing zone 78 being substantially vertical, it extends correspondingly to the fixing zone 44, ensuring pseudo-coplanarity between the zones 44 and 78 during fixing by the removable fixing system 46.

[0106] Thus, the blade 42B can be mounted vertically on the mast 40, the C-shaped section opening horizontally.

[0107] The removable fastening system 46 is for example formed by a zipper (commonly referred to as a “zip”). It notably comprises a Zipper® system comprising a first track 80 secured to the fastening zone 44, a second track 82 secured to the complementary fastening zone 78, and a member 84 for assembling the tracks 80, 82.

[0108] The assembly member 84 is permanently engaged on one of the tracks 80, 82. It is capable of engaging at one end of the other track 82, 80, to reversibly assemble the tracks 80, 82 onto each other by moving the assembly member 84 along the tracks 80, 82.

[0109] The rotation drive system 48 is visible for example in [Fig.l]. It comprises a rotating plate 90, and possibly a motor 92.

[0110] The motor 92 is capable of driving the rotating plate 90 in rotation around the vertical axis A-A' in increments, in particular in increments of between 1° and 30°, then to stop once the increment has been made to allow electromagnetic field measurements to be carried out at each receiver 24.

[0111] It is suitable for driving in joint rotation the inflatable parts of the electromagnetic stirrer 26 including the mast 40, and the blades 42A to 42C carried by the mast 40 over an angular displacement of at least 360° around the axis A-A'.

[0112] A method of mounting and installing the electromagnetic stirrer 26 will now be described.

[0113] Initially, the reverberation chamber 20 is already present, for example, within a building. Alternatively, the reverberation chamber 20 is mounted, for example by inflating the pillars and beams, causing the deployment of the intermediate reflective surfaces 30.

[0114] The electromagnetic stirrer 26 is then brought into the interior volume 28. Its inflatable parts are initially deflated and folded to be contained for example in the bag 50.

[0115] Advantageously, the rotation drive system 48 is placed on the floor of the chamber 20.

[0116] The mast 40 and a set of blades 42A to 42C are removed from the bag 50.

[0117] Preferably, a portion of the blades 42A to 42C among all the blades 42A to 42E available in the set of blades 42A to 42E are selected to be mounted on the mast 40, depending in particular on the dimensions of the reverberation chamber 20.

[0118] Preferably, the selected blades 42A to 42C are pre-assembled on the mast 40, when the mast 40 and the blades 42A to 42C are in their deflated configuration.

[0119] For this purpose, the complementary fixing zone 78 of each blade 42A to 42C is brought into the vicinity of a respective fixing zone 44 of the mast 40, and the tracks 80, 82 are joined to each other, by displacement of the assembly member 84.

[0120] The fixing of the blades 42A to 42C in the deflated configuration facilitates the positioning and assembly of the track 80 on the complementary track 82 and compensates for the pseudocoplanarity between the fixing zone 44 and the complementary fixing zone 78.

[0121] Then, the bladders of the mast 40 and of the inflatable frame 70 of each blade 42A to 42C are inflated. The mast 40 is erected, and the blades 42A to 42C are deployed radially away from the mast 40. The mast 40 and each blade 42A, 42B extend vertically. Each blade 42A to 42B opens horizontally opposite a respective angular sector around the axis A-A'.

[0122] The mast 40 is assembled by its lower end on the rotating plate 90. The electromagnetic stirrer 26 is then ready for use.

[0123] The platform 14 receiving the equipment is introduced into the interior volume 28 as well as the transmitter 22, before, during or after the assembly of the electromagnetic mixer 26.

[0124] The or each receiver 24 is placed in the vicinity of or in the equipment 12 within the platform 14.

[0125] To carry out the measurements, the electromagnetic stirrer 26 is successively pivoted in increments around its axis A-A', by successive rotations of the rotating plate 90.

[0126] Between each rotation of the electromagnetic stirrer 26, the transmitter 22 is activated to emit electromagnetic waves at a plurality of given frequencies in the aforementioned frequency range.

[0127] Each receiver 24 measures the intensity, frequency and / or phase of the electromagnetic waves received in the vicinity or in each equipment 12 for each angular orientation of the electromagnetic mixer 26, and for each transmission frequency.

[0128] As indicated above, over one revolution of the electromagnetic stirrer 26, the maximum value and the average value of the electromagnetic field are identical at all points of the reverberation chamber 20 and the electromagnetic field has rotated according to all polarizations.

[0129] The isotropy of the electromagnetic field can be verified by calculating the standard deviation of the components Ex, EY and Ez of the electromagnetic field at several points of the reverberation chamber 20, this standard deviation being less than 3dB for the horizontal part, as visible in [Fig.4].

[0130] The electromagnetic mixer 26 according to the invention therefore makes it possible to carry out measurement campaigns quickly and efficiently, whatever the weather conditions, by producing a very homogeneous electromagnetic field within the reverberation chamber 20.

[0131] The inflatable parts of the electromagnetic stirrer 26 are then deflated and stored, for example, in its bag 50, with a view to being transported to another site to carry out another measurement campaign.

[0132] Furthermore, if one of the blades 42A, 42B, 42C needs to be changed, it can be easily removed from the mast 40, by disengaging the complementary track 82 from the track 80 by moving the assembly member 84, then by assembling another blade, for example the blade 42D, in place of the blade 42C. This allows for great modularity in the dimensions and structure of the electromagnetic stirrer 26, depending on the extent of the volume 28 to be stirred.

[0133] The electromagnetic stirrer 26, at least partially inflatable, according to the invention is therefore very simple to use and takes up little space to store. It is robust and not very fragile. It is also low cost and very light, for example less than 15 kg.

[0134] Its assembly and disassembly is very quick, in less than an hour, in particular around fifteen minutes.

[0135] It has blades 42A to 42D with an original shape, which produce effective mixing of the electromagnetic field, avoiding cuts or injuries to operators.

[0136] The presence of a metallic layer on the blades 42A to 42E and on the mast 40 ensures effective reflection of electromagnetic waves throughout the radio and microwave range.

[0137] It is furthermore not necessary to ensure electrical continuity between the mast 40 and each blade 42A to 42E of the electromagnetic stirrer 26 to guarantee its proper operation.

[0138] The electromagnetic stirrer 26 is scalable, the shape of the blades 42A to 42E being able to be easily changed by manufacturing blades of different shapes, for example elliptical or circular, using other bladders, then by assembling these blades to the inflatable mast 40.

[0139] Such an electromagnetic stirrer 26 can therefore easily be used to certify and / or recertify aircraft in various locations. The electromagnetic stirrer 26 can be used for military or civil aircraft, or for electromagnetic tests to be carried out on other equipment 12, possibly present in other platforms, in particular satellites, naval platforms or terrestrial platforms such as automobiles.

Claims

Claims

1. Electromagnetic stirrer (26), comprising: - a mat (40); - at least one blade (42A to 42E) having a surface (72) reflecting radio waves and / or microwaves, in which the or each blade (42A to 42E) having a surface (72) reflecting radio waves and / or microwaves has at least two non-coplanar regions; the mat (40) having a blade attachment zone (44), the or each blade (42A to 42E) having a surface (72) reflecting radio waves and / or microwaves being fixed on the blade attachment zone (44); characterized in that at least a part of the mat (40) and / or of the or each blade (42A to 42E) having a surface (72) reflecting radio waves and / or microwaves is inflatable, in that the or each blade having a surface (72) reflecting radio waves and / or microwaves has the shape of a section of cylinder cut along a plane parallel to the axis of the cylinder.

2. Electromagnetic stirrer (26) according to claim 1, in which the or each blade (42A to 42E) having a surface (72) reflecting radio waves and / or microwaves is inflatable.

3. Electromagnetic stirrer (26) according to claim 2, comprising a system (46) for removable attachment of the or each blade (42A to 42E) having a surface (72) reflecting radio waves and / or microwaves on the blade attachment zone (44).

4. An electromagnetic stirrer (26) according to claim 3, wherein the fastening system (46) comprises a zipper.

5. An electromagnetic stirrer (26) according to any one of claims 2 to 4, wherein the or each blade (42A to 42E) having a surface (72) reflecting radio waves and / or microwaves has a lateral edge, the or each blade (42A to 42E) having a surface (72) reflecting radio waves and / or microwaves being fixed along its lateral edge to the blade fixing zone (44).

6. An electromagnetic stirrer (26) according to any one of claims 2 to 5, comprising a plurality of inflatable blades (42A to 42E) having a surface (72) reflecting waves radio and / or microwave, having different dimensions, the blade attachment zone (44) being suitable for interchangeably accommodating several blades (42A to 42E) of the plurality of inflatable blades (42A to 42E), each blade (42A to 42E) having a surface (72) reflecting the radio and / or microwave waves being suitable for being mounted as a replacement for another blade (42A to 42E) having a surface (72) reflecting the radio and / or microwave waves on the blade attachment zone (44).

7. An electromagnetic stirrer (26) according to any one of claims 2 to 6, wherein the or each inflatable blade (42A to 42E) having a surface (72) reflecting radio waves and / or microwaves has at least one region (60) having a C-shaped section, for example a single region having a C-shaped section (60), or a plurality of regions having a C-shaped section (60) arranged adjacent to each other.

8. Electromagnetic stirrer (26) according to any one of claims 2 to 7, in which the or each inflatable blade (42A to 42E) having a surface (72) reflecting radio waves and / or microwaves comprises an inflatable frame (70) and at least one layer reflecting radio and / or microwave electromagnetic waves carried by the inflatable frame (70).

9. Electromagnetic stirrer (26) according to claim 8, in which the frame (70) comprises at least two inflatable peripheral uprights (74A, 7AB) and at least one inflatable crosspiece (76A, 76B) connecting the inflatable peripheral uprights (74A, 74B) together.

10. An electromagnetic stirrer (26) according to any preceding claim, wherein the mat (40) is inflatable.

11. Electromagnetic stirrer (26) according to claim 10, in which the mast (40) is cylindrical with a vertical axis (A-A'), the blade attachment zone (44) extending along a generatrix of the mast (40).

12. Electromagnetic stirrer (26) according to any one of the preceding claims, comprising a rotating plate (90), the mast (40) carrying the or each blade (42A to 42E) having a surface (72) reflecting radio waves and / or microwaves being suitable for being mounted on the rotating plate (90) to be driven in rotation around a vertical axis (A-A') by the rotating plate (90).

13. Electromagnetic measuring and / or testing system (10) comprising: - a reverberation chamber (20); - a transmitter (22) of radio and / or microwave electromagnetic waves intended to be placed in the reverberation chamber (20); - possibly an electromagnetic wave receiver (24) intended to be placed in the vicinity of equipment (12) placed in the reverberation chamber (20); and - an electromagnetic mixer (26) according to any one of the preceding claims, intended to be placed in the reverberation chamber (20).

14. Method of mounting an electromagnetic stirrer (26), comprising the following steps: - providing a mast (40) and at least one blade (42A to 42E) having a surface (72) reflecting radio waves and / or microwaves, in which the or each blade (42A to 42E) having a surface (72) reflecting radio waves and / or microwaves has at least two non-coplanar regions; the mast (40) having a blade attachment zone (44), the or each blade (42A to 42E) having a surface (72) reflecting radio waves and / or microwaves being fixed to the blade attachment zone (44), at least a part of the mast (40) and / or of the or each blade (42A to 42E) being inflatable; the inflatable part of the mat (40) and / or of the or each blade (42A to 42E) having a surface (72) reflecting radio waves and / or microwaves being initially deflated, the method comprising a step of inflating the inflatable part of the mat (40) and / or of the or each blade (42A to 42E), in which the or each blade having a surface (72) reflecting radio waves and / or microwaves has the shape of a section of cylinder cut along a plane parallel to the axis of the cylinder.

15. A method according to claim 14, wherein the mat (40) and / or the or each blade (42A to 42E) having a surface (72) reflecting radio waves and / or microwaves is inflatable, the providing step comprising providing the mat (40) and / or the or each blade (42A to 42E) having a surface (72) reflecting radio waves and / or microwaves in a deflated and disassembled configuration, the method comprising assembling the or each blade (42A to 42E) having a surface (72) reflecting radio waves and / or microwaves in a deflated and disassembled configuration. microwave on the mat (40) before inflation, and inflation of the mat (40) and / or of the or each blade (42A to 42E) having a surface (72) reflecting radio waves and / or microwaves after assembly.

16. Electromagnetic measuring and / or testing method, comprising the following steps: - providing a reverberation chamber (20): - implementing a method for mounting an electromagnetic stirrer (26) according to claim 14 or 15, and arranging the electromagnetic stirrer (26) in the reverberation chamber (20); - arranging a transmitter (22) in the reflecting chamber, and; - emitting radio and / or microwave electromagnetic waves by the transmitter (22) into the reverberation chamber (20); - placing a receiver (24) in the reverberation chamber (20) in the vicinity of equipment (12) to be tested in the reverberation chamber (20) and measuring the electromagnetic field received by the receiver (24) and / or testing equipment (12) in operation in the reverberation chamber (20);the method comprising a step of rotating the electromagnetic stirrer (26) around an axis of rotation (A-A') between two successive measurements of the electromagnetic field received by the receiver (24) or between two successive tests of the equipment (12) in operation.;

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