A device for measuring the electromagnetic radiation of a radiating object

Abstract

A device for measuring the electromagnetic radiation of a radiating object. The invention relates to a device for measuring the electromagnetic radiation of a radiating object (10), comprising a sealed box (20) for housing the radiating object (10), means (12) for moving the radiating object (10) in a longitudinal direction (L), a thermal film (14) housed in the sealed box (20), a camera (16) housed at a longitudinal end of the sealed box (20) and located opposite the radiating object (10) to be measured relative to the thermal film and designed to acquire an image of the thermal film, and means (18) for processing the image acquired by the thermal film (4) designed to provide a map of the electromagnetic field of the radiating object (10).

Description

[Technical field]

[0001] The present invention relates to a device for measuring the electromagnetic radiation of a radiating object (radiating object), such as an antenna, in particular at radio or microwave frequencies. [Background technology]

[0002] The electromagnetic emissions of emitting objects such as antennas, radiotelephones, microwave transceivers, microwave devices, inductive devices, etc. often need to be known.

[0003] To this end, document WO 2020 / 0351193 proposes a device for measuring the performance capabilities of a radiating object in at least two different frequency bands, which includes an outer housing forming an outer chamber with radio frequency reflecting walls, an inner chamber with radio frequency absorbing walls in which the radiating object to be tested is housed, a first arrangement of test antennas housed in the outer chamber for measuring in the first frequency band, and a second arrangement of test antennas arranged inside the inner chamber for measuring in the second frequency band.

[0004] The device thus enables the performance of a radiating object to be measured in a reflected radio frequency environment by a first arrangement of the test antenna, and the performance to be measured in an essentially anechoic radio frequency environment by a second arrangement of the test antenna.

[0005] This solution does not allow the electromagnetic radiation of the antenna radiating object to be characterized, it only allows the performance of the radiating object to be measured in a predetermined frequency band. Furthermore, this solution is complex to implement and requires the use of two sets of test antennas.

[0006] The inventors therefore set out to develop a simpler integrated device that allows a radiating object to be characterised and the radiation pattern to be reconstructed. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] WO2020 / 0351193 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention aims to provide a device for measuring, characterizing and visualizing the electromagnetic radiation of an emitting object.

[0009] The invention aims in particular to provide such a measuring device which allows the measurement, characterization and visualization of the radiation of an emitting object for different frequencies.

[0010] The invention particularly aims to provide a measuring device which does not require the use of complex components and which has a limited number of components.

[0011] The invention has in particular an object to provide a measuring device which can be used without significant problems by anyone, without any particular technical knowledge of the operation of antennas.

[0012] The present invention also aims, in at least one embodiment, to provide a handheld device for measuring and characterizing the electromagnetic emissions of an emitting object. [Means for solving the problem]

[0013] To this end, the present invention comprises: a sealed box, impermeable to electromagnetic radiation, extending in the longitudinal direction and provided with an opening intended to allow the radiating object to be measured to be placed in the box; - means for modulating the radiation of a radiating object, The present invention relates to a device for measuring the electromagnetic radiation of a radiating object comprising:

[0014] The device according to the invention is characterized in that - means for longitudinally moving the radiating object inside the enclosure between a position called the proximal position and a position called the distal position; a heat-sensitive film that is heat-sensitive to an electromagnetic field, that is housed in a sealed box and that extends in a plane perpendicular to the longitudinal direction near the proximal position; a camera housed in a longitudinal end of the sealed box, opposite the radiating object to be measured relative to the thermal film, and configured to acquire an image of the thermal film, the thermal film being positioned at a focal distance from the camera; - means for processing the images acquired by the camera, configured to provide a map of the electromagnetic field acquired by the thermal film; The present invention further comprises:

[0015] The device according to the invention thus allows the electromagnetic field of a radiating object to be measured and a map provided. In particular and according to the invention, a thermal film heats up in contact with the electromagnetic radiation of the radiating object. This heating is imaged by a camera and then detected and characterized by image processing means. The thermal film can be either sensitive to magnetic fields or to electric fields. The thermal film is placed at a focal distance from the camera.

[0016] The device according to the invention allows any type of radiating object that can be contained in a sealed box to be examined, i.e. eliminating the need to use anechoic or reverberation chambers of the prior art solutions. In particular, the device according to the invention allows an image of the field emitted by a radio frequency and / or microwave source to be obtained without any special precautions. Such a device can therefore be used in classrooms, design offices and generally in any room that is not specially designed for electromagnetic radiation.

[0017] Throughout the text and depending on the application, radio waves (or Hertzian waves) will be taken to refer to electromagnetic waves having frequencies in the range between 3 Hz and 300 MHz, and microwaves will be taken to refer to electromagnetic waves having frequencies in the range between 300 MHz and 300 GHz.

[0018] The device according to the invention is an integrated device that does not require any external equipment other than an energy source for powering the radiation source, the camera, the image processing means and the means for longitudinally moving the emitting object, which, according to an advantageous variant, is formed by a rechargeable battery housed in a compartment adjacent to the hermetic housing.

[0019] Furthermore, the device according to the invention has particular features that allow longitudinal movement (for example using motorized means) of the emitting object relative to the thermal film between a distal position away from the thermal film and a proximal position close to the thermal film, which allows the electromagnetic radiation of the emitting object to be measured in different planes located at different distances from the thermal film. The device according to the invention thus allows a 3D reconstruction of the near-field amplitude to be generated by image processing means.

[0020] Furthermore, and in the case of an antenna, amplitude measurements in two different planes allow the field phase to be algorithmically reconstructed at any point of the antenna's aperture, i.e. the radiation pattern of this antenna to be reconstructed.

[0021] According to an advantageous embodiment, the camera is equipped with an image capture sensor in the visible range, and the device further includes a monochromatic light source housed in the box and directed towards and illuminating the thermal film, the film being coated with a layer of fluorescent material.

[0022] According to this alternative embodiment, the device is equipped with a camera with a CCD or CMOS sensor in the visible range. This camera is provided with an optical filter adapted to the wavelength of the fluorescent light emitted by the thermal film covered with a fluorescent dye. Furthermore, a light source housed in the box illuminates the thermal film.

[0023] The fluorescent material must be a fluorescent dye that emits in the visible range (approximately 400 nm to 800 nm) and has a fluorescence intensity that depends on temperature. According to one embodiment, the material used is Rhodamine B, whose maximum fluorescence intensity is approximately 600 nm at ambient temperature when it receives light of wavelength 470 nm, and undergoes a significant decrease in this intensity (approximately 2% / °C) when its temperature increases. The difference between the wavelengths received by the excitation and fluorescence facilitates the measurement since it will allow the filtering of the camera such that the reflection on the film of the emission light is eliminated without losing the useful signal.

[0024] Of course, other materials that are both fluorescent and heat sensitive can be used without questioning the principles of this advantageous embodiment.

[0025] According to a second embodiment, the camera is a camera equipped with an infrared sensor.

[0026] In this case, the camera captures the heat generation directly on the thermal film.

[0027] Regardless of the type of camera used (infrared or visible), the thermal film used is either weakly conductive (for electric field measurements) or insulating and magnetically lossy (for magnetic field measurements), i.e., under the influence of the electromagnetic field of a radiating object, the film heats up (typically within the range of 0.01 to 10°C).

[0028] This heating is the cause of variations in the fluorescence intensity recorded directly by an infrared camera (for the infrared version) or additionally by a camera in the visible range (for the fluorescent version).

[0029] Advantageously, the measuring device further comprises a filter arranged between the radiating object to be measured and the thermal film, the filter being configured to filter components of the electromagnetic field to enable measurements of other components of the electromagnetic radiation of the radiating object to be measured.

[0030] That is, and according to this advantageous variant, a filter is inserted so as to be sandwiched between the radiating body and the thermal film. This filter takes the form of, for example, a second thin film of the conductive or absorbing grating type or of the type with a specific pattern. This filter allows only the components that are not filtered out to pass through to the thermal film. That is, for example, it is possible to perform cross-polarized measurements. In the case of circularly polarized light, the right / left character can also be obtained using a filter film with an appropriate pattern, in particular a polarization-selective surface (known by the acronym PSS).

[0031] According to an advantageous variant of the invention, the thermal film is removably attached to the inside of the sealed box.

[0032] This variation allows the type of film to be easily and quickly changed. In particular and according to the invention, the type of thermal film used determines the type of field (electric or magnetic) that can be measured. For electric field measurements, weakly conductive films are used. For magnetic field measurements, insulating and magnetic lossy films are used.

[0033] This removable assembly can be of any type: it can for example be a frame onto which the film is placed, this frame being received in guide rails on the mutually facing inner walls of the box.

[0034] According to a particular embodiment of the invention, the thermal film is an anisotropic film for determining the field direction and its spatial variation or its ellipticity as a function of the polarization of the field emitted by the object to be measured.

[0035] According to this advantageous variant, the anisotropic film comprises an array of patterns for determining the spatial variation of the amplitude and of the direction (for linearly polarized light) or even of the amplitude and of the ellipticity (for circularly polarized light) of the field emitted by the emitting object.

[0036] Such anisotropic films are films with specific patterns (parallel strips, stars with 3 or more branches) that allow the amplitude as well as the polarization of the electric field, including the ellipticity in the case of circular polarization, to be determined. Using such an array of patterns, it is also possible to determine the spatial distribution of these amplitudes and polarizations in a plane.

[0037] According to a variant of the invention, the means for modulating the radiation of the emitting object comprise a microcontroller, a synthesizer and a radio frequency or microwave amplifier housed in dedicated compartments.

[0038] This modification allows the radiating object to be powered and controlled.

[0039] According to another variant of the invention, the means for modulating the radiation of the emitting body comprises: a shutter screen disposed between the emitting object and the thermal film and configured to be capable of transitioning from a state, referred to as a transparent state, in which radiation from the emitting object can reach the thermal film, to a state, referred to as an opaque state, in which the screen prevents radiation from the emitting object from reaching the thermal film; - control electronics configured to control the shutter screen between an opaque state and a transparent state and vice versa.

[0040] This deformation allows the fields of non-cooperative objects to be measured. A shutter screen placed in front of the thermal film ensures a low-frequency modulation of the object by opening and closing at the abovementioned frequencies, ranging from a few tenths to a few Hz. The shuttering can be achieved by electrical or mechanical means. A mechanical shutter consists, for example, of two parallel gates, each obscuring 50% of the thermal film, one of which oscillates laterally over a distance equal to the gate step, allowing 50% opening (superimposed gates) or closing (gates offset by one step). The electrical shutter can be a liquid crystal or plasma film (intermittent actuation ensuring alternation of opaque / transparent).

[0041] Advantageously, the means for longitudinally moving the emitting body includes a rail along which the emitting body can slide and an electric motor for moving the emitting body on the rail.

[0042] Other means for moving the emitting body between the proximal and distal positions may be implemented without altering the subject matter and results of the present invention.

[0043] In addition to the means for longitudinally moving the radiating body, provision can also be made for the device to be provided with means for pivoting the radiating body on itself in order to modify the angular aperture of the field measurement.

[0044] Advantageously and according to the invention, the electromagnetic radiation-tight enclosure is formed by a box with an inner wall covered with a microwave absorber.

[0045] These absorbers are configured to prevent any reflection of the electromagnetic field and to attenuate the emission of the field towards the outside of the enclosure.

[0046] The invention also relates to a measuring device characterized in combination by all or some of the features mentioned above or below.

[0047] Further objects, features and advantages of the present invention will appear on reading the following description, given purely as a non-limiting example and made with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0048] [Figure 1] FIG. 2 is a schematic perspective view of a measuring device according to an embodiment of the present invention with an infrared camera, further including a cutout for viewing elements present in the measuring device. [Diagram 2] 2 is a schematic perspective view of the device of FIG. 1 with a radiating object moved over and relative to a thermal film; [Diagram 3] FIG. 2 is a schematic perspective view of a measuring device according to another embodiment of the present invention, comprising a visible range camera further including a cutout for viewing elements present in the measuring device, and a light source for emitting fluorescent light. [Figure 4] FIG. 4 is a schematic perspective view of the device of FIG. 3 with a radiating object moved over and relative to a thermal film. [Diagram 5] FIG. 13 is a schematic perspective view of a measuring device according to another embodiment of the present invention with an additional filter positioned between the emitting body and the thermal film, further including a cutout for viewing elements present in the measuring device. [Figure 6] FIG. 2 is a schematic perspective view of a measuring device according to an embodiment of the present invention showing the cover of the device in an open position, which further includes a cutout for viewing elements present on the measuring device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049] In the figures, for the sake of illustration and clarity, scale and proportion are not strictly adhered to. Throughout the following detailed description with reference to the figures, unless otherwise noted, the elements of the measuring device are described as arranged when the emitting object is contained in the sealed box of the measuring device. This configuration is particularly shown in FIG.

[0050] Furthermore, identical, similar or analogous elements are designated using the same reference symbols in all figures. Finally, the terms longitudinal, lateral and vertical are used in a non-limiting manner with reference to a plane having three sides L, T and V as shown in Figure 1. The longitudinal direction corresponds to the main direction of the measuring device along which the emitting object can move. The vertical direction is the direction predetermined by gravity. The lateral direction is the direction perpendicular to the longitudinal and vertical directions.

[0051] 1 and 2 show a device for measuring the electromagnetic radiation of a radiating object 10, such as an antenna, according to a first embodiment.

[0052] According to this embodiment, the device includes a sealed box 20 formed by a bottom box 20a and a cover 20b, shown in FIG. 6, hinged onto the bottom box 20a.

[0053] The emitting body 10 is mounted on sliding rails 12 which form means for moving the emitting body 10 in the longitudinal direction L.

[0054] The emitting body 10 is capable of moving in a longitudinal direction L between a position called a proximal position, shown diagrammatically in FIGS. 1 and 3, and a position called a distal position, shown diagrammatically in FIGS.

[0055] This movement may be obtained by motorized means (not shown), such as an electric motor, which drives the emitting body 10 along the rail 12 .

[0056] The measuring device also comprises means 13 for modulating the radiation of the emitting object. These means are housed, for example, in a specific compartment 15 arranged at a first longitudinal end of the sealed box 20.

[0057] The measuring device also includes a heat-sensitive film 14 which is heat-sensitive to the electromagnetic field, is housed in a sealed box 20 and extends transversely near the proximal position, ie in a plane perpendicular to the longitudinal direction.

[0058] The measuring device also includes a camera 16 housed in a second longitudinal end of the sealed box 20 opposite the emitting object 10 to be measured against the thermal film 14 .

[0059] Finally, the measurement device includes a computer 18 forming means for processing the images obtained by the camera 16. This computer 18 includes software routines configured to provide a map of the electromagnetic field picked up by the thermal film 14.

[0060] In the embodiment of Figures 1 and 2, camera 16 is an infrared camera configured to directly capture the heat generated by the thermal film.

[0061] In the embodiment of figures 3 and 4, the camera 16 is a visible range camera, which is configured to capture the fluorescent light emitted by the thermal film 14 covered with a fluorophore. For this purpose, the device further comprises a light source 17 for illuminating the thermal film 14. In this case, the camera 16 comprises an optical filter adapted to the wavelength of the fluorescent light emitted by the thermal film covered with a fluorophore. The material covering the thermal film can be, for example, rhodamine B, whose maximum fluorescence intensity is about 600 nm at ambient temperature when subjected to light with a wavelength of 470 nm.

[0062] Regardless of the embodiment, the principles of the present invention are based on the interaction of a field emitted by an emitting body 10 with a film 14 .

[0063] This thermal film 14 is either weakly conductive (for electric field measurements) or insulating and magnetically lossy (for magnetic field measurements). Thus, under the influence of an electric field, the film heats up (typically in the range of 0.01 to 10° C.). This heating is the cause of the fluctuations in the fluorescence intensity that are recorded directly by the infrared camera (for the embodiments of FIGS. 1 and 2) or further by the camera 16 (for the embodiments of FIGS. 3 and 4).

[0064] The radiation of the emitting body 10 is given by: According to JPEG2025515273000002.jpg1239, the film 14 (which is a thin film, i.e., of very limited thickness compared to the coating thickness and the wavelength, and the field and temperature are assumed to be constant within the thickness of the film) is heated in proportion to the absorbed power density, where e represents the thickness of the film 14 and h is the convection coefficient. The absorbed power density is calculated according to the following formula: JPEG2025515273000003.jpg1386, where f represents the frequency of the radiation, σ represents the conductivity of the film 14, ε″ represents its permittivity (imaginary component), and μ″ represents its permeability (imaginary component).

[0065] For electric field measurements, the measuring device is equipped with an "electrically lossy" film, i.e. a film with low permittivity, negligible permeability, but non-zero conductivity, i.e. only the first component of the above equation is taken into account, and the power is proportional to the square of the electric field.

[0066] For magnetic field measurements, the measuring device is equipped with a "magnetically lossy" film, i.e. a film with high permeability but negligible conductivity and permittivity, i.e. only the second component of the above equation is taken into account and the power is proportional to the square of the magnetic field.

[0067] That is, for the embodiment of Figures 1 and 2 (infrared camera), computer 18 includes software routines configured to reconstruct from the thermal images acquired by camera 16 a map of the field (electric or magnetic) amplitude in the plane of the film (Oxy) from the square root of the heating and using a proportionality coefficient k that depends only on the film. The software means calculates the amplitudes: -For films with electrical losses, JPEG2025515273000004.jpg952 - For films with magnetic losses, It is programmed to calculate JPEG2025515273000005.jpg953.

[0068] For the embodiment of figures 3 and 4 (visible and fluorescent cameras), the image processing means 18 are configured to reconstruct, from the optical image captured by the camera 16, a map of the amplitude of the field (electric or magnetic) in the plane of the film (Oxy) from the square root of the fluorescence intensity (signal received by the camera) and using the coefficient g. In general, fluorescence decreases with temperature, so that fluorescence in the field-free ("cold") state gives an intensity I0, which is therefore reduced by the electric field (due to the temperature variations of the film that it induces) to I fluo The processing means 18 may, for example, determine the amplitude: For films with electrical losses, JPEG2025515273000006.jpg1273For a film with magnetic loss, JPEG2025515273000007.jpg1273

[0069] As mentioned above, the thermal film 14 will depend on the type of measurement being performed. The film is preferably removably mounted in a sealed box 20 for easy installation / replacement depending on the type of measurement being performed.

[0070] For the measurement of the amplitude of the electric field (E) of a radiating object 10, a weakly conductive thin film 14 is used, consisting of an electrically insulating matrix and a composite material based on conductive particles. The conductive particulate filler must be adjusted so that the absorber has a "low" surface impedance (=resistivity / thickness), i.e. a surface impedance in the range of 500 to 3,000 Ω, and absorbs only a part of the electric field. This surface impedance is adjusted as a function of the particle concentration in the insulating matrix and the thickness of the absorber layer. Carbon-filled polyimide (Kapton) with a thickness of a few tens of microns is an example of a film that can be used.

[0071] For magnetic field measurements, composites based on electrically insulating matrices and magnetic particles are used. The density of the ferromagnetic particles must be kept low enough to limit their absorption and therefore their disturbance to the magnetic field to be measured. In practice, polymer matrix films containing iron particles (volume fraction 10 to 20%) can be used perfectly well. Neutral films (electrically and magnetically) on which a solution containing magnetic nanoparticles is deposited can also be envisaged, with concentrations and thicknesses adapted to the measurements.

[0072] The measuring device preferably also comprises a compartment 15 housing the means 12 for modulating (regulating) the radiation of the emitting object.

[0073] These modulation means depend on the type of emitting object whose radiation is to be measured.

[0074] In particular, the measuring device according to the invention can have a transient mode and a low frequency modulation mode.

[0075] In the context of fast transient phenomena (i.e. not involving complex thermal phenomena such as conduction and convection), direct recording of images allows electromagnetic interpretation and transcription of the fields.

[0076] For example, in the context of direct harmonic powering (CW) of the radiation source, which is the standard mode for antennas, a low frequency modulation of the radiation source (from a few tenths of Hz to a few Hz) makes it possible to eliminate the thermal phenomena mentioned above, namely conduction in the film and convection with the surrounding air, in conjunction with a filtering (synchronous detection) of the recorded image. This synchronous demodulation further makes it possible to improve the signal-to-noise ratio and the measurement dynamics. In practice, the thickness of the film is about 100 microns or less. For typical characteristics of Kapton (measurement of E) or even polymer matrix films (measurement of H), the thermal time constant τ of the film is a few seconds, given by the following formula: JPEG2025515273000008.jpg1230Here, C is the heat capacity (unit: J / kg / K) and ρ is the density (unit: kg / m 3 ), h is the convection coefficient (unit: W / m2 / K), and e is the film thickness (unit: m).

[0077] Convective equilibrium is reached in a few seconds (film is heated to 1-e -t / τ ) the temperature rises and stabilizes according to an exponential law of 100 Hz (LF modulation does not allow time for this), so the temperature rise is reduced and can be linearized (e.g. triangular for a rectangular "all or nothing" type modulation of the radiation source).

[0078] That is, the modulation system is arranged to apply a modulation time sequence of electromagnetic radiation to which the film is exposed. The synchronous detection system is arranged to filter the intensities captured in successive images of the plane of the film according to the modulation time sequence. This can be done during measurement or also after recording is completed, for example by means of a Fast Fourier Transform (FFT).

[0079] In the event that the radiation source cannot be controlled, a shutter (mechanical or electrical) placed in front of the sensor film, controlled to open and close, can reproduce the modulation ("all or nothing"), thus allowing measurements with synchronous detection and corresponding to the previous case. The mechanical shutter can be formed, for example, by two parallel gates, each obscuring 50% of the film, one of which oscillates laterally over a distance equal to the gate step to allow 50% opening (superimposed gates) or closing (gates offset by one step). The electrical shutter can be a liquid crystal or plasma film (intermittent actuation to ensure alternation of opaque / transparent).

[0080] The device according to the invention allows a radiating object 10 to move along a longitudinal rail 12 .

[0081] The device according to the invention therefore enables the electromagnetic radiation of the emitting object 10 to be measured in different planes located at different distances from the thermal film 14. The device according to the invention thus enables a 3D reconstruction of the near-field amplitude to be produced by the image processing means 18.

[0082] In particular, in the case of an antenna, amplitude measurements in two different planes make it possible to obtain the phase of the electric field at every point of the aperture of the antenna and therefore to reconstruct the radiation pattern of this antenna. For this purpose, the image processing means can use software means to implement a method known as "planar near-field / far-field phase retrieval".

[0083] 5 shows an alternative embodiment of the measuring device in which a filter 19 is placed between the radiating object 10 to be measured and the thermal film 14. This filter is configured to filter components of the electromagnetic field and thus allow the measurement of other components of the electromagnetic radiation of the radiating object to be measured. This filter 19 is formed, for example, by a thin film of the conductive or absorbing grating type or of the type with a particular pattern, in particular a polarization selective surface (PSS). It allows only the components that are not filtered out to pass beyond the thermal film 14.

Claims

1. A sealed box (20) having an opening that allows a radiating object (10) that does not transmit electromagnetic radiation, extends in the longitudinal direction (L), and is to be measured to be housed in the box (10), Means for modulating the radiation of a radiating object (13), A device for measuring electromagnetic radiation from a radiating object (10) including, Means (12) for moving the radiating object (10) inside the sealed box (20) in the longitudinal direction (L) between a position called the proximal position and a position called the distal position, A thermal film (14) that is heat-sensitive to an electromagnetic field, is housed in the sealed box (20), and extends in a plane perpendicular to the longitudinal direction near the proximal position, A camera (16) is housed at the longitudinal end of the sealed box (20), is located on the opposite side from the radiating object (10) which will be measured relative to the thermal film (14), and is configured to acquire an image of the thermal film, wherein the thermal film (14) is positioned at a focal distance from the camera (16), The means (18) for processing the image acquired by the camera (16) is configured to provide a map of the electromagnetic field of the radiating object (10) acquired by the thermal film (4), A device characterized by further including the following.

2. The camera (16) is equipped with a sensor for acquiring images in the visible region. The device further includes a monochromatic light source (17) directed to illuminate the thermal film (14), The aforementioned film is coated with a layer of fluorescent material. The device according to feature 1.

3. The device according to claim 1, characterized in that the camera (16) is a camera equipped with an infrared sensor.

4. The device according to claim 1, wherein the means (13) for modulating the radiation of the radiating object (10) includes a microcontroller, a synthesizer, and a radio frequency or microwave amplifier housed in a dedicated compartment (15).

5. The means (13) for modulating the radiation of the radiating object is A shutter screen disposed between the radiating object (10) and the thermal film (14), wherein the shutter screen is configured to transition from a state called a transparent state in which the radiation from the radiating object can reach the thermal film to a state called an opaque state in which the screen prevents the radiation from the radiating object from reaching the thermal film, A control electronic device configured to control the shutter screen between the opaque state and the transparent state and vice versa, including, The device according to feature 1.

6. The device according to claim 1, further comprising a filter (19) positioned between the radiating object (10) to be measured and the thermal film (14), wherein the filter (19) is configured to filter out components of the electromagnetic field, thereby enabling the measurement of other components of the electromagnetic radiation of the radiating object (10) to be measured.

7. The device according to claim 1, wherein the thermal film (14) is an anisotropic film including an array of patterns for determining the spatial variation of the amplitude and direction of the field (for linearly polarized light) or the spatial variation of the amplitude and ellipticity of the field (for circularly polarized light) emitted by the radiating object (10).

8. The device according to claim 1, characterized in that the thermal film (14) is detachably mounted inside the sealed box (20).

9. The device according to claim 1, wherein the means (12) for moving the radiating object (10) in the longitudinal direction (L) includes a rail along which the radiating object (10) can slide, and an electric motor for moving the object on the rail.

10. The device according to claim 1, characterized in that the sealed box (20) that does not allow electromagnetic radiation to pass through is formed by a box having an inner wall covered with a microwave absorber.

Images