Passive wireless electronic component and associated reading system

Abstract

Passive wireless electronic component and associated reading system The invention relates to a passive wireless electronic component (2) comprising at least one antenna (14), the antenna or antennas having an associated antenna frequency, and comprising at least one resonant microelectromechanical component, having a resonant frequency and connected to a contact point of said antenna, forming an antenna-resonator assembly adapted to receive an incident electromagnetic signal (Si) comprising at least two frequencies and to emit a backscattered electromagnetic signal (Sr).This passive wireless electronic component (2) is such that the antenna or antennas (14) comprise at least two non-linear actuation resonant MEMS microelectromechanical components (16, 18), each of said MEMS components having a natural mechanical resonance frequency belonging to a range of resonance frequencies, the resonance frequency ranges associated with two distinct MEMS components being disjoint. Figure 1.

Description

Title of the invention: Passive wireless electronic component and associated reading system

[0001] The present invention relates to a passive wireless electronic component and an associated reading system.

[0002] The invention lies in the field of passive electronic components, and more particularly passive electronic sensors and resonators.

[0003] A passive wireless electronic component is a component that does not include a power source or a power rectifier. Such a component is also called a remotely powered component.

[0004] The sensors are, in a known manner, electronic or electromechanical components adapted to measure a physical quantity, for example temperature, pressure, humidity, etc.

[0005] Various types of remotely powered passive sensors have been developed, such sensors having the advantage of operating without an integrated power source, which makes them usable in difficult environments, for example in installations operating at high temperatures.

[0006] In the state of the art, several families of passive wireless sensors are distinguished, in particular LC resonant circuit sensors, acoustic wave sensors and electromagnetic transduction sensors.

[0007] LC resonant circuit sensors are based on a capacitive sensor connected in series or parallel with an inductive loop, forming a resonant circuit. The resonant frequency of the circuit is modified by the variation in capacitance of the sensor depending on the physical quantity to be measured. Such resonant circuit sensors have the disadvantage of a short reading distance, less than 10 cm.

[0008] Acoustic wave sensors comprise a surface acoustic wave or SAW (from the English "Surface Acoustic Wave") or bulk acoustic wave or BAW (from the English "Bulk Acoustic Wave") sensor, powered by an antenna, itself remotely powered. This type of sensor has losses due to the double conversion between acoustic wave and electromagnetic wave, but also to the propagation of the acoustic wave in particular.

[0009] Electromagnetic transduction sensors combine a sensor with an antenna, which powers the sensor, the electromagnetic signal emitted (or backscattered) by the antenna in response to an incident electromagnetic signal being used to determine a value of a measured physical quantity, the properties of the backscattered electromagnetic signal being modified depending on the sensor. Such sensors Electromagnetic transduction has the disadvantage of the sensitivity of the antenna to the external environment. For example, temperature can vary the permittivity of the substrate on which the antenna is printed, and modify the resonant frequency of the antenna, and consequently induce an inaccuracy in the measured value of the physical quantity considered.

[0010] Patent EP 2 478 636 B1, entitled “Wireless MEMS sensor and its reading method” describes an electronic component, typically a sensor, comprising an assembly formed by an antenna and a microelectromechanical system (MEMS) type resonator connected to the antenna, which makes it possible to read a physical quantity measured as a function of the resonance frequency of the MEMS resonator, by an intermodulation technique. The MEMS resonator is characterized by two parameters, respectively the mechanical quality factor, the mechanical resonance frequency, the antenna having an electrical resonance frequency, and at least one of these three parameters is sensitive to the physical quantity measured. The intermodulation voltage makes it possible to generate an oscillation of the MEMS resonator in response to incident electromagnetic energy at two different frequencies.Although more robust to environmental conditions than an antenna, such a MEMS resonator can nevertheless also be impacted by environmental conditions, and therefore provide an inaccurate measurement of physical quantity. Moreover, in this technology, the radiofrequency antenna is a single antenna adapted to the MEMS resonator, in other words the limitation of a single MEMS resonator per antenna is imposed, which induces a significant footprint when several sensors are required.

[0011] The invention aims to remedy the drawbacks of the state of the art by providing a passive electronic component of limited size and / or better precision for measuring a physical quantity.

[0012] To this end, the invention proposes, according to one aspect, a passive wireless electronic component comprising at least one antenna, the or each antenna having an associated antenna frequency, and comprising at least one resonant microelectromechanical component, having a resonance frequency and connected to a contact point of said antenna, forming an antenna-resonator assembly adapted to receive an incident electromagnetic signal comprising at least two frequencies and to emit a backscattered electromagnetic signal. This electronic component is such that the or each antenna comprises at least two resonant microelectromechanical, MEMS, components with non-linear actuation, each of said MEMS components having a specific mechanical resonance frequency belonging to a range of resonance frequencies, the ranges of resonance frequencies associated with two distinct MEMS components being disjoint.

[0013] Advantageously, the proposed passive wireless electronic component comprises at least two microelectromechanical, MEMS, components resonating on the same antenna, the resonant frequencies of the two resonant MEMS components belonging to disjoint ranges, which makes it possible to differentiate the responses of the resonant MEMS components to an incident electromagnetic signal comprising chosen frequencies.

[0014] The passive wireless electronic component according to the invention may also have one or more of the characteristics below, taken independently or in any technically conceivable combination:

[0015] It comprises a number N of antennas, N being greater than or equal to two, each antenna comprising at least two microelectromechanical components, MEMS, resonant with non-linear actuation, each antenna having its own antenna frequency, the antenna frequencies of two distinct antennas being different.

[0016] At least one of said at least two resonant MEMS components is a capacitive resonator.

[0017] At least one of said at least two resonant MEMS components is a resonant MEMS sensor whose resonant frequency varies as a function of a predetermined physical quantity.

[0018] The predetermined physical quantity is a physical quantity characteristic of an environment of the MEMS sensor resonating among temperature, air or gas pressure, humidity.

[0019] The passive wireless electronic component comprises a plurality of resonant MEMS sensors, each of said resonant MEMS sensors having a resonant frequency varying as a function of a distinct physical quantity, said passive electronic component being adapted to provide measurements of a plurality of distinct physical quantities.

[0020] The passive wireless electronic component comprises at least one pair of a first and a second resonant MEMS components, the first MEMS component being a resonant MEMS sensor whose resonant frequency varies as a function of a first physical quantity to be measured and as a function of at least one second physical quantity, the second MEMS component of said pair being a resonant MEMS sensor whose resonant frequency does not vary as a function of said first physical quantity, the resonant frequency of the second sensor varying as a function of said at least one second physical quantity.

[0021] Said at least two resonant MEMS components are connected in series or in parallel.

[0022] Said at least one antenna is produced in the form of a printed circuit on a substrate, and said MEMS components are produced on one or more chips in silicon, each MEMS component being connected to an antenna element by wire bridging.

[0023] Said antenna and said at least two resonant MEMS components are implanted on the same silicon substrate.

[0024] Each resonant MEMS component is formed by a membrane positioned between two electrodes, of circular shape and having an associated radius.

[0025] According to another aspect, the invention relates to a system for reading a passive wireless electronic component of the type briefly described above, the system comprising a said passive wireless electronic component and a device for transmitting and analyzing electromagnetic signals, configured to transmit said incident electromagnetic signal to the passive electronic component and to receive and analyze the backscattered electromagnetic signal.

[0026] This reading system has advantages similar to those of the passive wireless electronic component.

[0027] According to one embodiment, the transmission and analysis device comprises a module generating an electrical signal and an antenna for transmitting and reading an incident electromagnetic signal, the transmission and reading antenna also being adapted to receive the electromagnetic signal backscattered by the antenna of the passive electronic component, the transmission and analysis device further comprising a signal processing module, configured to analyze the frequency characteristics of the backscattered electromagnetic signal.

[0028] Other characteristics and advantages of the invention will emerge from the description given below, for information purposes only and in no way limiting, with reference to the appended figures, among which:

[0029] [Fig.l] [Fig.l] is a functional schematic illustration of a system comprising an electronic component according to one embodiment;

[0030] [Fig.2] [Fig.2] illustrates a first embodiment of an electronic component seen from below;

[0031] [Fig.3] [Fig.3] schematically represents in section the MEMS components in the first embodiment;

[0032] [Fig.4] [Fig.4] represents an electrical circuit equivalent to the electronic component in the first embodiment;

[0033] [Fig.5] [Fig.5] schematically illustrates the variation of the capacitance as a function of the pressure of a resonant membrane MEMS sensor;

[0034] [Fig.6] [Fig.6] illustrates operating graphs associated with the membrane resonant MEMS sensor;

[0035] [Fig.7] [Fig.7] represents a graph of variation of the power of the modulation of the backscattered signal received as a function of the resonance frequencies specific to the resonant MEMS components in the first embodiment of the electronic component;

[0036] [Fig.8] [Fig.8] illustrates a second embodiment of an electronic component;

[0037] [Fig.9] [Fig.9] schematically represents in section a part of [Fig.8] illustrating a MEMS component and its connection to an antenna element;

[0038] [Fig. 10] [Fig. 10] illustrates a third embodiment of an electronic component.

[0039] [Fig.l] schematically illustrates, by functional modules, a system 1 for reading a passive wireless electronic component according to one embodiment.

[0040] The system 1 comprises a passive wireless electronic component 2, several detailed embodiments of which will be described below, and a device 4 for transmitting and analyzing electromagnetic signals associated with the passive wireless electronic component.

[0041] The device 4 comprises a module 6 generating an electrical signal and a transmission and reading antenna 8.

[0042] According to a variant not shown, the device 4 comprises two separate antennas, a transmission antenna and a reading antenna.

[0043] The electrical signal is transformed into an incident electromagnetic signal Si, also called an incident electromagnetic wave, emitted by the transmission and reading antenna 8. The incident electromagnetic signal Si comprises at least two frequencies, as described in more detail below.

[0044] The transmitting and reading antenna 8 is also adapted to receive an electromagnetic signal Sr backscattered by the antenna 14 of the passive wireless electronic component 2.

[0045] The transmitting and reading antenna 8 is connected to a signal processing module 10, implementing several signal processing functionalities including an analysis of the frequency characteristics of the backscattered electromagnetic signal Sr.

[0046] The device 4 further comprises a calculation module 12, which uses the frequency characteristics obtained to provide a result, for example a value of a measured physical quantity or several values ​​of measured physical quantities.

[0047] Modules 6, 10, 12 are electronic modules.

[0048] For example, module 12 is a calculation processor or a microcontroller.

[0049] The passive electronic component 2 is a wireless component comprising at least one antenna 14, to which are connected at least two microelectromechanical components, hereinafter called MEMS, which are resonant components with non-linear actuation each having its own mechanical resonance frequency.

[0050] For example, the dimensions of the antenna 14 are millimetric, of the order of several millimeters in length and width or diameter depending on the antenna geometry. MEMS components have micrometric dimensions.

[0051] For the same antenna, the mechanical resonance frequency of one of the MEMS components is strictly different from the mechanical resonance frequency of another MEMS component positioned on said antenna.

[0052] In other words, each MEMS component of the same antenna has a specific mechanical resonance frequency, hereinafter called the specific resonance frequency, belonging to a range of resonance frequencies, the ranges of resonance frequencies associated with two distinct MEMS components being disjoint.

[0053] The resonance frequency range associated with a MEMS component is called a frequency range, [f_min, f_max], the natural resonance frequency fm belonging to the range [f_min, f_max].

[0054] Two respective resonant frequency ranges, [fl_min, fl_max] and [f2_min, f2_max], are said to be disjoint when the smallest upper frequency limit of one of the frequency ranges, for example fl_max, is strictly lower than the lower frequency limit, for example f2_min, of the other frequency range.

[0055] The antenna 14 is adapted to operate in reception in a frequency band called the antenna bandwidth, [Fa ± A ], where Fa is the electrical resonance frequency of the antenna, called the antenna frequency hereinafter.

[0056] For example, the antenna 14 is adapted to operate in a frequency band belonging to the frequency band between 300 MHz and 3 GHz, also called the UHF band.

[0057] A non-linearly actuated resonant component is understood to mean a component whose actuating force is proportional to an electrical parameter (for example, an actuating voltage), more particularly proportional to an electrical parameter squared. The component will then be actuated at the intermodulated frequencies of the electrical actuating signal. For example, if the electrical signal Se = A(COS27Tfl + A2cos27rf2, the actuation force will be proportional to 52 and therefore F? des.cos2æ( / + / J+ ^0cos2tt( / - / V

[0058] In the embodiment illustrated in [Fig.l], the passive wireless electronic component 2 comprises an antenna 14, to which a first non-linearly actuated resonant MEMS component 16 and a second non-linearly actuated resonant MEMS component 18 are connected.

[0059] In one embodiment, MEMS components 16 and 18 are placed on antenna 14, each being connected to antenna 14 at a contact point.

[0060] According to one embodiment, each of the resonant MEMS components 16, 18 is connected to the antenna 14 at the same contact point.

[0061] According to another embodiment, each of the resonant MEMS components 16, 18 is connected to the antenna 14 at a separate contact point.

[0062] The resonant MEMS components 16, 18 are connected in parallel or in series.

[0063] In one embodiment, the antenna is produced on a substrate in the form of a printed circuit, and each MEMS component is produced on a silicon chip, the MEMS components being connected to the antenna by means of wire bonding connections.

[0064] In an alternative embodiment, the antenna 14 and the connected MEMS components are produced on the same silicon substrate.

[0065] In the example of [Fig.2], the passive wireless electronic component 2 comprises an antenna 14.

[0066] In an alternative embodiment, the passive wireless electronic component 2 comprises a number N of antennas, N being greater than or equal to two, each comprising at least two microelectromechanical components, MEMS, resonant with non-linear actuation, each antenna having an antenna frequency which is specific to it and which is different from the antenna frequency of each of the N1 other antennas.

[0067] More generally, each antenna comprises a number P of resonant MEMS components with non-linear actuation, P being greater than or equal to 2.

[0068] In one embodiment, each of the MEMS components 16, 18 is a capacitive resonator.

[0069] In one embodiment, at least one of the resonant MEMS components is a resonant MEMS sensor whose mechanical resonant frequency varies as a function of a predetermined physical quantity, for example a capacitive MEMS sensor.

[0070] For example, the physical quantity is temperature, air or gas pressure, humidity.

[0071] In the reading system of a passive wireless electronic component 2, the incident electromagnetic signal Si comprises at least two close frequencies, respectively a first frequency fe and a second frequency fe+fm, these two frequencies being in the bandwidth of the antenna 14. By adjusting the second frequency relative to the first frequency, one or other of the resonant MEMS components 16, 18 of the antenna is put into resonance, this resonance modulating in amplitude the electromagnetic signal Sr backscattered by the antenna.

[0072] By studying, by scanning a set of frequencies fm, the spectral characteristics of the backscattered electromagnetic signal, it is determined for which second frequency fe+fm of the incident electromagnetic signal Si the amplitude of the modulation of the backscattered electromagnetic signal Sr varies the most. Thus, the device 4 detects the resonant frequency at which one of the resonant MEMS components of the antenna put into resonance.

[0073] The ranges of resonant frequencies of the MEMS components of the electronic component being disjoint, the reading makes it possible both to distinguish which resonant MEMS component of the antenna 14 is in resonance and to detect its resonant frequency.

[0074] When the resonant MEMS component is a resonant MEMS sensor, for example capacitive, whose mechanical resonance frequency varies with a given physical quantity, a value of the physical quantity considered is deduced therefrom by the calculation module 12.

[0075] Thus, advantageously, in one embodiment, the passive wireless electronic component 2 comprises a plurality of distinct capacitive MEMS sensors, the different sensors each having a mechanical resonance frequency varying with a distinct physical quantity. This makes it possible to measure a plurality of values ​​of distinct physical quantities, while limiting the size of the component 2.

[0076] A first embodiment of an electronic component 20 is described with reference to FIGS. 2 and 3.

[0077] [Fig. 2] represents a view, called a bottom view, of the component 20, this component comprising a planar antenna 14 comprising two nested radiating loops 22, 24, and a set 30 of MEMS components.

[0078] The antenna 14 is for example produced in the form of a conductive track printed on a substrate 15, for example by PCB manufacturing technology.

[0079] The assembly 30 comprises, in this example, two MEMS components 26, 28, which are for example capacitive MEMS sensors of the circular membrane type, connected in parallel and represented schematically in [Fig.3].

[0080] As illustrated in [Fig.3], each MEMS sensor 26, 28 is placed on a substrate 33 made of silicon, and is connected to the radiating loop 24 via conductive tracks 32, 34, and bridging wires 35 (wire bonding).

[0081] By way of non-limiting example, the assembly 30 is formed on a substrate 33, of parallelepiped shape, with a rectangular base of millimetric dimensions, for example 1.1 mm in width and 1.7 mm in length.

[0082] In this embodiment, each of the two MEMS sensors 26, 28 is composed of a circular silicon membrane, separated from a fixed electrode by a vacuum cavity of given thickness g0, preferably between 1 and 7 micrometers (qm), for example equal to 2.5qm.

[0083] In this example, the electronic component performs a pressure sensor functionality, the first MEMS sensor 26 being a sensor configured to measure pressure, the second MEMS sensor 28 being a reference sensor, allowing to refine the pressure measurement as a function of temperature. The two MEMS sensors 26, 28, simply called sensors 26, 28 hereinafter, form a pair consisting of a measurement sensor and a reference sensor.

[0084] The first sensor 26 is a capacitive pressure sensor, also sensitive to temperature.

[0085] The second sensor 28 of the embodiment of [Fig.2] is a so-called reference sensor, of the same type as the first sensor 26, but whose mechanical resonance frequency does not vary as a function of the pressure.

[0086] For example, in one embodiment, the membrane of this second sensor 28 is perforated, which makes it insensitive to pressure. The other characteristics of the second sensor, for example the surface of the membrane and the material from which the membrane is made, are identical to the characteristics of the first sensor.

[0087] An equivalent electrical circuit of the electronic component forming an antenna-sensor system of [Fig.2] is illustrated in [Fig.4].

[0088] The electrical operation of the antenna is considered equivalent to a series RCL circuit, the respective values ​​of resistance R, capacitance C and inductance L being dependent on the electromagnetic characteristics of the antenna.

[0089] The first sensor 26 has a capacitance Ci(P,T) which varies as a function of pressure and temperature, and the second sensor 28 has a capacitance C2(T) which varies as a function of temperature.

[0090] Figures 5 and 6 illustrate the operation of a MEMS membrane pressure sensor, for example the first sensor 26, for a given temperature T.

[0091] The operation of a membrane pressure sensor is illustrated schematically in [Fig.5], for a given temperature.

[0092] The membrane 23 is assimilated to a capacitive component of capacity Co formed between two electrodes 25 and 27 when the membrane 23 is at rest, the membrane 23 being placed on a cavity 38, empty or filled with air.

[0093] The external pressure (pressure of the sensor environment), shown diagrammatically by arrows 29 in [Fig.4], causes the membrane to deflect and modifies the capacitance C(P), where C(0)=C0, between the two electrodes 25 and 27.

[0094] Associated operating graphs, in an operating example, are illustrated in [Fig.6].

[0095] At a given temperature T, the resonance frequency of the first sensor 26 evolves as a function of the pressure, between 0 bar and 1 bar.

[0096] An example of evolution is illustrated in graph G1 of [Fig.6], in which the abscissa axis represents the pressure, with a variation between 0 bar and 1 bar, and the ordinate axis the resonance frequency of the membrane, between 1.810 MHz and 1.820 MHz.

[0097] Graph G2 of [Fig.6] illustrates the evolution of the capacity C(P) as a function of the time, the abscissa axis of graph G2 representing the time between 0 and 2.5 iis, the ordinate axis the capacitance C(P) in picoFarads. The evolution of the capacitance is sinusoidal in response to the incident electromagnetic signal Si.

[0098] The variation in capacitance results in a variation in the backscattered electromagnetic signal over time, making it possible to detect the resonance frequency of the sensor membrane.

[0099] In the embodiment of [Fig.2], the vibrations of the second sensor 28 are independent of pressure, but dependent on temperature.

[0100] The resonance frequency of the second sensor 28 is a reference resonance frequency fref dependent on the temperature T: [okh] f ïrUffo, J ref\ / J ■ J

[0102] Where T denotes the temperature, and fc is the resonant frequency of the first sensor 26, dependent on the pressure and the temperature. In other words, the resonant frequency of the second sensor is equal to the resonant frequency of the first sensor at a pressure equal to 0 bar and at the same temperature.

[0103] In an example application, the given temperature is the ambient temperature, for example To=20 °C. For example, the resonant frequency of the antenna is Fa =868 MHz.

[0104] For example, the first resonant frequency fc of the first sensor 26 varies in the resonant frequency range 1.81 to 1.82 MHz and the second resonant frequency of the second sensor 28 varies in the resonant frequency range 1.02 to 1.07 MHz.

[0105] In this example, the antenna-sensor system is designed so that at 868 MHz, and at a pressure equal to zero bar, the power of the backscattered electromagnetic signal sent by the antenna is maximum.

[0106] In one embodiment, the device 4 for transmitting and analyzing electromagnetic signals sends an electromagnetic signal Si of frequency 868 MHz, amplitude modulated with a modulation frequency fm varying in the frequency range [ / ,.(0, T)].

[0107] The frequency range pa + y ( ()_ py Fa + f (1, ] is included in the band antenna bandwidth.

[0108] For each of the sensors, the electrical force created in the capacitance is proportional to the voltage across the sensor terminals squared.

[0109] When the modulation frequency fm is equal to the mechanical resonance frequency of one of the sensors, the force generated is of the form:

[0110] Fe(t) =----—t + Msin{2jrfmt) - [YES]

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122] Where Co is the capacity at zero bar, g0 is the cavity thickness, w(r) is the deflection from a point r of the radius of the membrane due to the pressure, Vo is the tension at between the terminals of the electrical circuit equivalent to zero bar, and M is the modulation index of the signal S;. By varying the fm frequency on the frequency range (0, T): f (1, 7^] we obtains a maximum of the power variation of the backscattered signal at two distinct frequency values, corresponding to the respective resonance frequencies, i.e. the first resonance frequency Fi=fc(P,T) of the first pressure sensor and the second resonance frequency F2=fref(0,T) of the second sensor (reference sensor). The variation of the power of the backscattered electromagnetic signal Sr as a function of frequency is illustrated in graph G3 of [Fig.7], in which the y-axis represents the power of the backscattered electromagnetic signal and the x-axis the frequency. In the example of [Fig.7]; the resonant frequency of the second sensor (reference resonant frequency) F2 is lower than the first resonant frequency Fi of the first pressure sensor. The second resonant frequency (or reference resonant frequency) provides information on the temperature of the environment in which the electronic component is placed. Taking into account the first resonant frequency of the first sensor and the reference resonant frequency together allows for a more accurate evaluation of the pressure, taking into account the temperature. For example, the reference sensor is previously characterized in temperature, and the evolution of its mechanical resonance frequency as a function of temperature is memorized. In addition, advantageously, two measurements of physical quantities are obtained, a temperature measurement and a pressure measurement. [Fig.8] illustrates a second embodiment of an electronic component 40, in which the electronic component comprises three resonant MEMS components with non-linear actuation, and more particularly three capacitive MEMS sensors of the circular membrane type. Similarly to [Fig.2], [Fig.8] illustrates a schematic view from below the electronic component 40. In this second embodiment, the electronic component 40 comprises a planar antenna 14 comprising three nested loops. Component 40 comprises three antenna loops, 42, 44, 46, each comprising a MEMS component 48, 50, 52, the MEMS components being, for example, capacitive MEMS sensors.

[0123] For example, the component 40 comprises a first capacitive MEMS sensor 48 for measuring humidity, a second capacitive MEMS sensor 50 for measuring temperature, and a third capacitive MEMS sensor 52 for measuring pressure.

[0124] In this second embodiment, each capacitive MEMS sensor is connected at a separate contact point to the antenna 14, on a separate antenna loop.

[0125] Each of the capacitive MEMS sensors is, in one embodiment, analogously connected in the manner to the connection illustrated in [Fig.3].

[0126] [Fig.9] illustrates the connection of the MEMS sensor 48 to the antenna loop 42 in the embodiment of [Fig.8], the connection of the other MEMS sensors 50, 52 to the other antenna loops being analogous.

[0127] A MEMS component 48, on a substrate 54, is connected to an antenna element 42 via conductive tracks 56, and wire bonding wires 58.

[0128] According to a variant, the first, second and third capacitive MEMS sensors 48, 50, 52 are for example connected in parallel or in series at the same contact point of the antenna 14.

[0129] Similarly, each of these capacitive MEMS sensors has a natural resonant frequency, belonging to a range of natural resonant frequencies, the ranges of resonant frequencies of three sensors being disjoint.

[0130] Thus, three distinct physical quantities are measurable, by applying the measurement method described above with reference to [Fig.2], for example temperature, humidity and pressure.

[0131] Of course, temperature, humidity and pressure are examples of measurable physical quantities, the invention being applied in a similar manner for the measurement of other physical quantities.

[0132] In one embodiment, the antenna 14 is made by printing on a substrate via printed circuit manufacturing technology, and each MEMS component is made on a silicon substrate.

[0133] In another embodiment, the antenna 14 and the plurality of capacitive MEMS sensors are implanted on the same substrate, for example a silicon substrate, using microsystem manufacturing technologies. The connection between each capacitive MEMS sensor and the antenna is then made with conductive tracks.

[0134] [Fig. 10] illustrates an example of a third embodiment of a passive wireless electronic component 60, illustrated in a “top” view.

[0135] In this embodiment, called antenna array, the electronic component comprises N antennas, N=4 in the illustrated example, referenced 62h 622, 623, 624, the generic reference 62; being used to indicate any one of these antennas.

[0136] Each antenna 62; comprising two nested loops 64;, 66;, and two distinct resonant MEMS components, respectively 68;, 70;, each respective MEMS component being connected to one of the antenna loops and having a specific resonant frequency, belonging to a resonant frequency range, the resonant frequency ranges being disjoint for two distinct resonant MEMS components 68;, 70;.

[0137] In this third embodiment, each antenna 62; has its own antenna frequency Fa_i, the resonance frequencies of two separate antennas being strictly different.

[0138] In this case, the reading, for example the detection of the resonance of a given resonant MEMS component 64;, 66; is done using the resonance frequency of the antenna Fa_i and its own resonance frequency Fl_i, F2_i.

[0139] The antenna frequencies Fa_i being all distinct, it is possible to provide, in a variant, resonant MEMS components of the same resonance frequencies associated with distinct antennas, ie Fl_i=Flj and F2_i=F2j for i different from j.

[0140] This third embodiment is particularly suitable, using resonant MEMS sensors, for the study of localized variations of the same physical quantities on a surface.

[0141] In a variant, the resonant MEMS components of the third embodiment are capacitively actuated MEMS resonators, the resonance of one of these resonators making it possible to identify the associated antenna.

[0142] The exemplary embodiments of the invention given above comprise a planar antenna with nested loops.

[0143] Alternatively, other types of antenna can be used, in particular planar antennas having a different geometry, for example patch or dipole, or a non-planar antenna, for example a horn antenna.

[0144] The invention has been described with resonant MEMS components of the vibrating membrane type. Alternatively, other types of resonant MEMS components can be used, for example vibrating beam.

[0145] Thus, according to one variant, resonant MEMS components of various geometries, for example with vibrating membrane and vibrating beam, are integrated on the same antenna.

[0146] According to another variant, the vibration non-linearity of the MEMS component is obtained by an external component, for example a diode.

[0147] Advantageously, an electronic component according to the invention is remotely powered and has a reduced size, while allowing the measurement of several physical quantities and / or an improvement in the precision of the measurement of one or more of the physical quantities measured.

Claims

Claims

1. Passive wireless electronic component comprising at least one antenna, the or each antenna having an associated antenna frequency, and comprising at least one resonant microelectromechanical component, having a resonance frequency and connected to a contact point of said antenna, forming an antenna-resonator assembly adapted to receive an incident electromagnetic signal comprising at least two frequencies and to emit a backscattered electromagnetic signal, characterized in that the or each antenna (14, 62b ..., 624) comprises at least two microelectromechanical components (16, 18, 26, 28, 48, 50, 52, 681-684, 70i-704), MEMS, resonant with non-linear actuation, each of said MEMS components having a specific mechanical resonance frequency belonging to a range of resonance frequencies, the ranges of resonance frequencies associated with two distinct MEMS components being disjoint.

2. Component according to claim 1, comprising a number N of antennas, N being greater than or equal to two, each antenna comprising at least two microelectromechanical components, MEMS, resonant with non-linear actuation, each antenna having its own antenna frequency, the antenna frequencies of two separate antennas being different.

3. A component according to claim 1 or 2, wherein at least one of said at least two resonant MEMS components is a capacitive resonator.

4. A component according to claim 1 to 3, wherein at least one of said at least two resonant MEMS components is a resonant MEMS sensor whose resonant frequency varies as a function of a predetermined physical quantity.

5. Component according to claim 4, wherein said predetermined physical quantity is a physical quantity characteristic of an environment of the MEMS sensor resonating among temperature, air or gas pressure, humidity.

6. A component according to claim 4 or 5, comprising a plurality of resonant MEMS sensors, each of said resonant MEMS sensors having a resonant frequency varying as a function of a distinct physical quantity, said passive electronic component being adapted to provide measurements of a plurality of distinct physical quantities.

7. Component according to claim 4 to 6, comprising at least one pair of a first and a second resonant MEMS components, the first MEMS component being a resonant MEMS sensor whose resonant frequency varies as a function of a first physical quantity to be measured and as a function of at least one second physical quantity, the second MEMS component of said pair being a resonant MEMS sensor whose resonant frequency does not vary as a function of said first physical quantity, the resonant frequency of the second sensor varying as a function of said at least one second physical quantity.

8. Component according to one of claims 1 to 7, wherein said at least two resonant MEMS components are connected in series or in parallel.

9. Component according to any one of claims 1 to 8, wherein said at least one antenna is produced in the form of a printed circuit on a substrate, and said MEMS components are produced on one or more silicon chips, each MEMS component being connected to an antenna element by wire bridging.

10. Component according to any one of claims 1 to 8, wherein said antenna and said at least two resonant MEMS components are implanted on the same silicon substrate.

11. A component according to claim 9 or 10, wherein each resonant MEMS component is formed by a membrane positioned between two electrodes, of circular shape and having an associated radius.

12. System for reading a passive electronic component, comprising a passive electronic component according to claims 1 to 11 and a device (4) for transmitting and analyzing electromagnetic signals, configured to transmit said incident electromagnetic signal to the passive electronic component and to receive and analyze the backscattered electromagnetic signal.

13. System according to claim 12, wherein said transmission and analysis device (4) comprises a module (6) generating an electrical signal and an antenna (8) for transmitting and reading an incident electromagnetic signal (Si), the transmission and reading antenna (8) also being adapted to receive the electromagnetic signal (Sr) backscattered by the antenna (14) of the passive electronic component (2, 20, 40, 60), the transmission and analysis device (4) further comprising a signal processing module (10), configured to analyze the characteristics frequency characteristics of the backscattered electromagnetic signal (Sr).

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