Multi-antenna radio frequency device including an energy harvesting antenna

Abstract

An electrical device (2) comprising a primary antenna (15) and at least one secondary antenna (16) having a resonant frequency different from that of the primary antenna, the electrical device (2) being arranged to be powered via the primary antenna by primary energy from primary electromagnetic waves emitted by an interrogating device (1) on a primary frequency band including the primary frequency, and to exchange data with said interrogating device via the primary antenna, the electrical device (2) also being arranged to receive via the secondary antenna additional electromagnetic waves present in its environment on a secondary frequency band including the secondary frequency, and to be powered by additional energy from the additional electromagnetic waves. (Figure from the summary: Fig. 2)

Description

Title of the invention: Multi-antenna radiofrequency device comprising an energy harvesting antenna

[0001] The invention relates to the field of remotely powered devices, and in particular devices integrated into aircraft.

[0002] BACKGROUND OF THE INVENTION

[0003] It is envisaged to integrate into an aircraft a system comprising an interrogator device and an electrical device, located at a certain distance from the interrogator device. The interrogator device and the electrical device each comprise at least one antenna, and are not connected by a wired connection. The electrical device integrates for example an RFID (for “Radio Frequency Identification”) type tag. In this case, the antenna in question is integrated into the RFID type tag.

[0004] The electrical device can also be integrated on or in equipment (electrical or not).

[0005] To interrogate the electrical device, the interrogating device emits electromagnetic waves via its antenna which are captured by the electrical device via its antenna. The electrical device is powered by the energy from these waves, and is thus “remotely powered” by the interrogating device. The interrogating device and the electrical device also exchange data via these antennas.

[0006] The system therefore uses either RFID or a communication and remote power supply technique similar to RFID.

[0007] Conventionally, when an RFID tag is interrogated, it transmits in return an identifier which is for example representative of the equipment to which it is attached. The identifier thus retransmitted in response characterizes for example the equipment in a unique way.

[0008] This technique is therefore particularly interesting for acquiring equipment identifiers, but also when the electrical device is integrated into electrical equipment which itself integrates or is connected to one or more sensors.

[0009] It is indeed sometimes very difficult to connect by cables a data concentrator (the interrogating device) and electrical equipment integrating a sensor or connected to a sensor, in particular when the electrical equipment is located on a moving part. It may also be, in such a case, that it is impossible to equip the electrical equipment with a power source such as a cell or a battery, for reasons of size or reasons related to the environment of the electrical equipment (high temperatures for example). The use of tele- food is then very interesting.

[0010] It is noted that the interrogator device can itself be integrated into the aircraft, or can be brought close to it by an operator on the ground.

[0011] One of the applications envisaged is a system which comprises interrogator devices located on the aircraft's engine masts, and electrical devices on the engine nacelles.

[0012] The main performance limitation in terms of range of this type of system is the limitation of the power of the interrogation signal generated by the interrogating device.

[0013] The power limitation results from standards specific to the field of telecommunications, but also from constraints specific to integration into an aircraft.

[0014] For example, the ETSI EN 302 208 standard limits the effective radiated power in the 865 MHz - 868 MHz band to 2W. In addition, aeronautical standards are very strict regarding radiofrequency energy emissions, to avoid disrupting the operation of other equipment.

[0015] The power limitation necessarily induces a limitation of the interrogation range.

[0016] However, the nacelles generally have dimensions that exceed the range capabilities of RFID systems when the power is limited to 2W. It is therefore necessary to multiply the on-board transmitting antennas, and to multiply the transmission points due to the distance. This significantly increases the weight and size of the system, which is prohibitive for many “RFID” type application projects on nacelles.

[0017] Furthermore, the environmental standards applicable to aviation, particularly civil aviation, require a contribution to be made to the fight against climate change. The Applicant takes into consideration the factors impacting all phases of design and development to obtain less energy-intensive, more environmentally friendly aeronautical components and products whose integration and use in civil aviation have moderate environmental impacts with the aim of improving the energy efficiency of aircraft.

[0018] Sustained research and development work thus focuses on new generations of aircraft engines, the lightening of aircraft, in particular through the materials used and lighter on-board equipment, the development of the use of electrical technologies to ensure propulsion, and, as essential complements to technological progress, aeronautical biofuels.

[0019] In this context, it is relevant to optimize the performance of the aforementioned electrical equipment by allowing better use of electrical power and an increase in the interrogation range.

[0020] Solutions have been considered in the prior art, in the field of RFID, to increase the interrogation range.

[0021] The multiple interrogation solution consists, when the RFID tag is too far from the antenna of the interrogating device to respond from the first interrogation, in interrogating the RFID tag several times, at very short time intervals. The circuit of the RFID tag thus retains a residual energy between two interrogations which is added to the energy received during each interrogation. After several interrogations, the tag has captured enough energy to respond to the request.

[0022] The time between interrogation repetitions must be compatible with the residual charge duration of the RFID tag circuit. The conservation of residual energy lasts for a very short time, so that the number of interrogations used to power the tag is limited.

[0023] This solution has the advantage of increasing the query range. However, the number of queries required reduces the possible refresh rate of the data.

[0024] The multiple interrogation solution, combined with the integration of one or more capacitors in the RFID tag circuit, makes it possible to accumulate energy at each interrogation, then to redistribute the accumulated energy to the circuit when the quantity of energy required for its operation is sufficient.

[0025] This solution has the advantages of increasing the interrogation range, and of less limiting the quantity of maximum interrogations which can be used to feed the tag.

[0026] However, again, the number of queries required reduces the possible refresh rate of the data.

[0027] SUBJECT OF THE INVENTION

[0028] The subject of the invention is:

[0029] - to increase the distance between an interrogating device and an electrical device, the electrical device being preferably positioned on board an aircraft, comprising for example an RFID tag and being at least partially powered by said interrogator device, or

[0030] - at an equivalent distance, to increase the data refresh rate emitted by the electrical device. Summary of the invention

[0031] With a view to achieving this aim, an electrical device is proposed comprising a primary antenna having a primary frequency as its resonant frequency, and at least one secondary antenna having a frequency as its resonant frequency. secondary different from the primary frequency, the electrical device being arranged to be powered via the primary antenna by a main energy from main electromagnetic waves emitted by an interrogator device on a primary frequency band comprising the primary frequency, to receive first data emitted by the interrogator device via the primary antenna, and to transmit second data to the interrogator device via the primary antenna, the electrical device also being arranged to pick up via the secondary antenna additional electromagnetic waves which are present in its environment on a secondary frequency band comprising the secondary frequency, and to be powered by additional energy from the additional electromagnetic waves.

[0032] The secondary antenna of the electrical device therefore allows it to recover additional energy from additional electromagnetic waves present in the environment of the electrical device.

[0033] These additional waves are not necessarily intended for the electrical device.

[0034] This additional energy constitutes an energy supplement which is added to the energy transmitted by the interrogating device, which the electrical device receives via its main antenna. The electrical device can therefore be positioned at a greater distance from the interrogating device or, at the same distance, can transmit data with a higher refresh rate.

[0035] We further propose an electrical device as previously described, comprising at least one RFID type tag, in which the primary antenna is integrated, the second data comprising at least one identifier of the electrical device and / or an identifier of a piece of equipment with which the electrical device is associated.

[0036] An electrical device as previously described is further proposed, the electrical device being arranged to be integrated into electrical equipment comprising a sensor or being connected to a sensor, the second data comprising measurements produced by said sensor.

[0037] An electrical device as previously described is further proposed, in which the primary frequency and the secondary frequency belong to the frequency band 860 MHz - 960 MHz.

[0038] We further propose an electrical device as previously described, further comprising at least one electrical card on which are mounted:

[0039] - a primary rectifier connected to the primary antenna;

[0040] - for each secondary antenna, a secondary rectifier connected to said antenna secondary;

[0041] - a voltage regulator connected to the primary rectifier and to each se- secondary, and arranged to produce a supply voltage for the electrical card;

[0042] - a demodulator connected to the primary antenna and arranged to produce a signal incoming digital containing the first data transmitted by the interrogating device;

[0043] - a processing component connected to the demodulator and arranged to acquire the incoming digital signal and to produce, intended for the interrogating device and in response to the first data, an outgoing digital signal comprising the second data;

[0044] - a retro-modulator connected to a load connected to the primary antenna and arranged to acquire the outgoing digital signal and to modulate the load so as to retro-modulate the main electromagnetic waves and thus transmit the outgoing digital signal to the interrogating device.

[0045] A system is further provided comprising an interrogator device and an electrical device as previously described.

[0046] There is further provided an aircraft comprising a system as previously described, and further comprising a reactor nacelle and a reactor mast, the interrogator device being positioned on the reactor mast and the electrical device on the nacelle.

[0047] An aircraft as previously described is further proposed, the electrical device being positioned on a thrust reverser of the nacelle.

[0048] A power supply method is further proposed, implemented in an electrical device as previously described, comprising the steps of:

[0049] - capture via the primary antenna the main electromagnetic waves emitted by the interrogating device, and powering the electrical device using the main energy from said main electromagnetic waves;

[0050] - capture additional electromagnetic waves via the secondary antenna, and also power the electrical device using additional energy from additional electromagnetic waves;

[0051] the additional electromagnetic waves not being intended for the electrical device.

[0052] A power supply method is further proposed, implemented in an electrical device as previously described, comprising the steps of:

[0053] - capture via the primary antenna the main electromagnetic waves emitted by the interrogating device, and powering the electrical device using the main energy from said main electromagnetic waves;

[0054] - capture additional electromagnetic waves via the secondary antenna, and also power the electrical device using additional energy from additional electromagnetic waves;

[0055] the additional electromagnetic waves being emitted by the inter- device rogator or other equipment, to the electrical device.

[0056] The invention will be better understood in light of the following description of a particular non-limiting embodiment of the invention. Brief description of the drawings

[0057] Reference will be made to the attached drawings, among which:

[0058] [Fig-1] [Fig.l] is a schematic side view showing an airplane wing (in section), a reactor mast, a nacelle, an interrogator device and an electrical device;

[0059] [Fig.2] [Fig.2] represents the interrogating device and the electrical device;

[0060] [Fig.3] [Fig.3] represents the electrical device and, in particular, the antenna primary and the two secondary antennas;

[0061] [Fig.4] [Fig.4] represents the electrical card within the electrical device and illustrates a first phase of an interrogation cycle;

[0062] [Fig.5] [Fig.5] is a figure similar to [Fig.4], and illustrates a second phase of the interrogation cycle;

[0063] [Fig.6] [Fig.6] is a figure similar to [Fig.4], and illustrates a third phase of the interrogation cycle;

[0064] [Fig.7] [Fig.7] is a figure similar to [Fig.4], and illustrates a fourth phase of the interrogation cycle;

[0065] [Fig.8] [Fig.8] is a figure similar to [Fig.4], and illustrates a fifth phase of the interrogation cycle;

[0066] [Fig.9] [Fig.9] is a figure similar to [Fig.4], and illustrates a sixth phase of the interrogation cycle. DETAILED DESCRIPTION OF THE INVENTION

[0067] With reference to [Fig.l], an aircraft incorporates an interrogator device 1 and an electrical device 2. The electrical device 2 here comprises at least one identification tag (here only one), such as an RFID (for “Radio Frequency Identification”) type tag. The RFID tag is preferably a passive type tag, supplied with electrical energy by the interrogator device 1 for its activation.

[0068] The interrogator device 1 is here positioned on the reactor mast 3 (also called “pylon”) which connects the wing 4 to a reactor. The electrical device 2 is positioned on the nacelle 5 of the reactor, and more precisely preferably on a flap 13 of a thrust reverser of the nacelle 5.

[0069] With reference to Figures 2 and 3, the interrogator device 1 comprises a processing unit 6, a communication module 7 and an antenna 8.

[0070] The communication module 7 comprises a transmission block 9 comprising a mo- dulator 10, and a reception block 11 comprising a demodulator 12.

[0071] The antenna 8 of the interrogator device 1 preferably has a resonant frequency which is included in the frequency band 860 MHz - 960 MHz, and which here more preferably belongs to the frequency band 865 MHz - 868 MHz. The resonant frequency of the antenna 8 is in this case equal to 866.5 MHz. The bandwidth at -3 dB of the antenna 8 is here between 851.5 MHz and 881.5 MHz.

[0072] The electrical device 2, for its part, comprises a primary antenna 15 having a primary frequency as its resonant frequency, and at least one secondary antenna 16 having a secondary frequency as its resonant frequency different from the primary frequency.

[0073] The primary antenna 15 is integrated into the RFID tag 14 of the electrical device 2.

[0074] The electrical device 2 comprises in this case a first secondary antenna 16a and a second secondary antenna 16b.

[0075] The primary antenna 15 has as its resonant frequency a primary frequency which is here preferably included in the frequency band 860 MHz - 960 MHz, and which here more preferably belongs to the frequency band 865 MHz - 868 MHz. The primary frequency is in this case equal to 866.5 MHz. The bandwidth at -3 dB of the primary antenna is here between 851.5 MHz and 881.5 MHz.

[0076] The first secondary antenna 16a has as its resonant frequency a first secondary frequency which is preferably higher than the primary frequency. The first secondary frequency is here included in the frequency band 860 MHz -960 MHz. The first secondary frequency is in this case equal to 896.5 MHz. The bandwidth at -3 dB of the first secondary antenna 16a is here between 881.5 MHz and 911.5 MHz.

[0077] The second secondary antenna 16b has as its resonant frequency a second secondary frequency which is preferably higher than the primary frequency and the first secondary frequency. The second secondary frequency is here included in the frequency band 860 MHz - 960 MHz. The second secondary frequency is in this case equal to 926.5 MHz. The bandwidth at -3 dB of the second secondary antenna 16b is here between 911.5 MHz and 941.5 MHz.

[0078] The electrical device 2 also comprises an electrical card 17 on which the primary antenna 15 is superimposed. The electrical card 17 is also integrated into the RFID tag 14.

[0079] Electrical components are mounted on the electrical board 17.

[0080] With reference to figures 4 to 9, these electrical components here comprise a primary rectifier 19 and, for each secondary antenna 16a, 16b, a secondary rectifier 20: we therefore have here a first secondary rectifier 20a and a second re- secondary trainer 20b.

[0081] The electrical components further comprise a voltage regulator 22, a demodulator 23, a modulator 24, a clock generator 25, a processing component 26 and a memory component 27. The voltage regulator 22 integrates for example a function for resetting the processing component 16 (this type of component is called Regulator / POR (for Power ON Reset)).

[0082] The modulator 24 is here a retro-modulator. The processing component 26 is here a baseband processor. The memory component 27 is here a memory bank.

[0083] The primary rectifier 19 is connected to the primary antenna 15 and to the input of the voltage regulator 22. The first secondary rectifier 20a is connected to the first secondary antenna 16a and to the input of the voltage regulator 22. The second secondary rectifier 20b is connected to the second secondary antenna 16b and to the input of the voltage regulator 22. The output of the voltage regulator 22 is connected to the clock generator 25 and to the processor 26. The input of the demodulator 23 is connected to the primary antenna 15. The output of the demodulator 23 is connected to the processor 26. The processor 26 is connected to the demodulator 23, to the retro-modulator 24, to the memory bank 27, to the clock generator 25 and to the voltage regulator 22. The retro-modulator 24 is connected to a load (not shown) which is itself connected to the primary antenna 15.

[0084] The interactions between the interrogator device 1 and the electrical device 2 during an interrogation cycle are described more precisely.

[0085] In Figures 4 to 9, the solid arrows represent the flow of energy, the solid arrows represent the flow of data, and the dotted arrows represent the flow of clock signals.

[0086] The interrogator device 1 produces an interrogation request to the electrical device 2. This interrogation request is included in a digital interrogation signal Sni (visible in [Fig.2]).

[0087] The transmission block 9 acquires the digital interrogation signal Sni, and generates and amplifies an electrical excitation signal Se (analog). The modulator 10 modulates the excitation signal Se with the digital interrogation signal Sni. The excitation signal Se thus contains first data comprising the request transmitted by the interrogator device 1. The electrical excitation signal Se is applied to the input of the antenna 8. The interrogator device 1 thus transmits, on a primary frequency band comprising the primary frequency, main electromagnetic waves carrying a main electromagnetic energy and the first data.

[0088] The electrical device 2 captures the main electromagnetic waves via its primary antenna 15.

[0089] The electrical device 2 further captures, thanks to its secondary antennas 16, additional electromagnetic waves which are present in its environment and which are not intended for it. These electromagnetic waves are for example produced by various electrical equipment (but not by the interrogating device 1). The secondary antennas 16 therefore allow for example the electrical device 2 to recover additional electrical energy which would be unused by the electrical device 2 without the presence of said secondary antennas 16.

[0090] The electrical device 2 therefore picks up additional electromagnetic waves via the first secondary antenna 16a on the first secondary frequency band comprising the first secondary frequency. The electrical device 2 picks up additional electromagnetic waves via the second secondary antenna 16b on the second secondary frequency band comprising the second secondary frequency.

[0091] With reference to [Fig.4], the primary antenna 15 therefore produces a primary voltage Vp, and a primary current Ip under the primary voltage Vp. The primary voltage Vp is applied to the input of the primary rectifier 19 and the demodulator 23.

[0092] The first secondary antenna 16a produces a first secondary voltage Vsl, and a first secondary current Isl under the first secondary voltage Vsl. The first secondary voltage Vsl is applied to the input of the first secondary rectifier 20a.

[0093] The second secondary antenna 16b produces a second secondary voltage Vs2, and a second secondary current Is2 under the second secondary voltage Vs2. The second secondary voltage Vs2 is applied to the input of the second secondary rectifier 20b.

[0094] The demodulator 23 demodulates the primary voltage Vp and thus generates an incoming digital signal Sne. The demodulator 23 transmits the incoming digital signal Sne to the processor 26.

[0095] The primary rectifier 19, the first secondary rectifier 20a and the second secondary rectifier 20b produce a rectified voltage Vr, and a rectified current Ir under the rectified voltage Vr. The rectified voltage Vr supplies the voltage regulator 22.

[0096] With reference to [Fig.5], the voltage regulator 22 generates a supply voltage Va for the electrical card 17, also continuous, and supply currents Ia under the voltage Va.

[0097] The supply voltage Va supplies the clock generator 25 and the processor 26.

[0098] With reference to [Fig.6], the clock generator 25 transmits a clock signal CLK to the processor 26.

[0099] The processor 26 acquires the incoming digital signal Sne, decodes it, and obtains the first data transmitted by the interrogating device 1. The processor 26 processes the interrogation request contained in the first data.

[0100] With reference to [Fig.7], the processor 27 interrogates the memory bank 27, and acquires second data which correspond to the request of the interrogating device 1. The second data here comprise at least one identifier of the equipment on which the electrical device 2 is positioned. The identifier(s) thus comprise for example a P / N (Part Nurnbef) or an S / N (Serial Nurnbef) of the thrust reverser comprising the flap 13.

[0101] With reference to [Fig.8], the processor 26 then remains on standby until the end of the interrogation and produces, intended for the interrogating device 1 and in response to the first data, an outgoing digital signal Sns comprising the second data. The processor 26 transmits the outgoing digital signal Sns to the retro-modulator 24.

[0102] With reference to [Fig.9], the retro-modulator 24 acquires the outgoing digital signal Sns and transforms it into a modulated signal Sm which is applied to the terminals of the load connected to the primary antenna 15. The retro-modulator 24 thus modulates said load so as to retro-modulate the main electromagnetic waves and thus transmit the outgoing digital signal Sns to the interrogator device 1.

[0103] The retro-modulation of the main electromagnetic waves, and therefore the impedance variations of the primary antenna 15, resulting from the modulated signal, are picked up by the reception block 11 of the interrogator device 1 via its antenna 8. The antenna 8 produces a response signal Sr (analog). The demodulator 12 of the reception block 11 in turn performs a demodulation of the response signal Sr and transmits a digital response signal Snr to the processing unit 6 of the interrogator device 1. The processing unit 6 thus acquires the second data corresponding to the interrogation request.

[0104] The secondary antennas 16 of the electrical device 2 therefore allow the capture of electromagnetic waves from secondary frequency bands, which are different from the primary frequency band used for the interrogation and response of the electrical device 2.

[0105] The electrical device 2 captures electromagnetic waves which are not directly intended for it, and therefore recovers lost energy.

[0106] The waves thus captured are converted into electrical energy by the secondary rectifiers 20.

[0107] This additional electrical energy supplies the circuit of the electrical device 2, and therefore reduces the quantity of energy needing to be supplied via the primary frequency band.

[0108] The additional energy, produced by the secondary antennas 16, therefore allows to increase the interrogation range of the electrical device 2 without increasing the transmission power of the interrogator device 1 on the primary frequency band. It is thus possible to increase the data refresh frequency limit at equal range in distances requiring multi-interrogation of equipment of conventional design.

[0109] The secondary frequency bands, and therefore the definition of the secondary antennas, are determined by an analysis of the frequencies present in the environment of the electrical device. They are selected to avoid any interference with other equipment present in the environment of the electrical device.

[0110] Of course, the invention is not limited to the embodiment described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0111] In the described embodiment, the additional electromagnetic waves are waves present in the environment of the electrical device and recovered by the electrical device, which are not emitted by the interrogating device and which are not intended for the electrical device. This is therefore a kind of energy harvesting.

[0112] However, the additional electromagnetic waves could be emitted by the interrogating device and intended for the electrical device. The interrogating device in this case also comprises one or more secondary antennas which transmit only energy.

[0113] The additional electromagnetic waves could also be intended for the electrical device but be emitted by equipment other than the interrogator device. For example, there could be dedicated equipment on the wing or on the reactor mast which emits additional electromagnetic waves at low power to a plurality of electrical equipment.

[0114] The performance of the system (range, refresh) is therefore increased by emitting, in parallel with the interrogation signal, one or more complementary power supply signals, without exceeding the standard signal power limits.

[0115] The application in which the invention is implemented could be different from that described here. The system comprising (at least) one interrogator device and (at least) one electrical device can be integrated into another part of the aircraft. The system could also be integrated into an application not belonging to the aeronautical field.

[0116] The interrogator device could be mobile equipment, brought close to the aircraft by an operator.

[0117] The frequencies used may be different from those described here. The higher the frequency, the greater the amount of radio energy that can be transported.

[0118] The frequency band 860 MHz - 960 MHz is used here, and contains both the primary frequency band and the secondary frequency bands. One or more other frequency bands could be used.

[0119] For example, the 3 GHz - 30 GHz frequency band could be used for the secondary antenna(s) (in energy recovery in particular).

[0120] The number and type of antennas may be different from those described herein. Each antenna will be particularly suited to the frequency band for which it is intended. The quantities defining each antenna may vary depending on the antenna type and technology: complex impedance, reactance, resistance, etc.

[0121] The electrical components cited are provided as examples, and could be different. For example, the processing component of the electrical board of the electrical device is not necessarily a baseband processor. It could be a microcontroller, an FPGA (for Field Programmable Gate Array), an ASIC (for Application Specified Integrated Circuit), etc.

[0122] It is possible to integrate one or more capacitors into the circuit of the electrical device to accumulate energy and redistribute it to the rest of the electrical device.

[0123] The electrical device does not necessarily incorporate an RFID type tag.

[0124] The electrical device can be associated with any type of equipment, be integrated into any type of equipment (and therefore be equipment itself).

[0125] It has been described here that the second data, transmitted by the electrical device to the interrogating device, comprises one or more identifiers of the equipment with which the electrical device is associated. The identifier(s) could be one or more identifiers of the electrical device itself.

[0126] The electrical device could be equipment comprising any one or more sensors, or being connected to any one or more sensors (temperature, pressure, vibration sensor(s), etc.). The electrical device could also be integrated into such equipment.

[0127] In this case, the second data may include measurements made by the sensor(s).

[0128] The second data may also include different data, for example equipment monitoring data, any messages (alarm for example), etc.

Claims

Claims

1. Electrical device (2) comprising a primary antenna (15) having a primary frequency as its resonant frequency, and at least one secondary antenna (16) having a secondary frequency different from the primary frequency as its resonant frequency, the electrical device (2) being arranged to be powered via the primary antenna by main energy from main electromagnetic waves emitted by an interrogator device (1) on a primary frequency band comprising the primary frequency, to receive first data emitted by the interrogator device via the primary antenna, and to transmit second data to the interrogator device via the primary antenna, the electrical device (2) also being arranged to pick up via the secondary antenna additional electromagnetic waves which are present in its environment on a secondary frequency band comprising the secondary frequency,and to be powered by additional energy from additional electromagnetic waves.,

2. Electrical device according to claim 1, comprising at least one RFID type tag, in which the primary antenna is integrated, the second data comprising at least one identifier of the electrical device and / or an identifier of equipment with which the electrical device is associated.

3. Electrical device according to one of claims 1 or 2, the electrical device being arranged to be integrated into electrical equipment comprising a sensor or being connected to a sensor, the second data comprising measurements produced by said sensor.

4. Electrical device according to one of the preceding claims, wherein the primary frequency and the secondary frequency belong to the frequency band 860 MHz - 960 MHz.

5. Electrical device according to one of the preceding claims, further comprising at least one electrical card (17) on which are mounted: - a primary rectifier (19) connected to the primary antenna (15); - for each secondary antenna (16), a secondary rectifier (20) connected to said secondary antenna; - a voltage regulator (22) connected to the primary rectifier (19) and to each secondary rectifier (20), and arranged to produce a voltage power supply (Va) of the electrical card; - a demodulator (23) connected to the primary antenna and arranged to produce an incoming digital signal (Sne) containing the first data transmitted by the interrogator device (1); - a processing component (26) connected to the demodulator and arranged to acquire the incoming digital signal and to produce, intended for the interrogator device and in response to the first data, an outgoing digital signal (Sns) comprising the second data; - a retro-modulator (24) connected to a load connected to the primary antenna (15) and arranged to acquire the outgoing digital signal and to modulate the load so as to retro-modulate the main electromagnetic waves and thus transmit the outgoing digital signal to the interrogator device.

6. System comprising an interrogator device (1) and an electrical device (2) according to one of the preceding claims.

7. An aircraft comprising a system according to claim 6, and further comprising a reactor nacelle (5) and a reactor mast (3), the interrogator device (1) being positioned on the reactor mast and the electrical device (2) on the nacelle.

8. Aircraft according to claim 7, the electrical device being positioned on a thrust reverser of the nacelle.

9. Power supply method, implemented in an electrical device according to one of claims 1 to 5, comprising the steps of: - capturing via the primary antenna the main electromagnetic waves emitted by the interrogator device, and powering the electrical device using the main energy from said main electromagnetic waves; - capturing via the secondary antenna the additional electromagnetic waves, and also powering the electrical device using the additional energy from the additional electromagnetic waves; the additional electromagnetic waves not being intended for the electrical device (2).

10. Power supply method, implemented in an electrical device according to one of claims 1 to 5, comprising the steps of: - capturing via the primary antenna the main electromagnetic waves emitted by the interrogator device, and powering the electrical device using the main energy from said main electromagnetic waves; - capture additional electromagnetic waves via the secondary antenna, and also power the electrical device using the additional energy from the additional electromagnetic waves; the additional electromagnetic waves being emitted by the interrogating device (1) or by other equipment, to the electrical device (2).

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