Circuit for a passive radio frequency identification tag comprising a strain sensor and method for manufacturing a circuit

Abstract

This invention relates to a circuit (1) for a passive radio identification tag operating in the UHF band, the circuit (1) being configured to radioly communicate with a reader that transmits a read signal. The circuit is manufactured as a single chip, the single chip including one or more transducers for measuring strain, a first sub-circuit (43) configured to acquire transducer measurements, and a second sub-circuit (2, 3) configured to radioly transmit the acquired measurements to the reader. The invention also relates to a system and method.

Description

Technical Field

[0001] This invention relates to contactless devices, such as RFID-type contactless devices, which include sensors for recording events over extended periods without the need for an external power source. Specifically, the invention relates to circuitry for passive radio identification tags operating in the UHF band, the circuitry being configured to radioly communicate with a reader that transmits periodic read signals, wherein the period of the read signals includes a power recovery phase and a communication phase. Background Technology

[0002] Existing technology

[0003] In a manner known in the prior art, RFID (Radio Frequency Identification) type circuits can be used as RFID tags (also known as markers) and associated with objects to be monitored. The circuit includes, or optionally connects via an interface with sensors, to measure at least certain physical parameters associated with the object, such as ambient temperature, humidity, or acceleration.

[0004] This circuit typically takes the form of an adhesive label stuck to the object being monitored or a device integrated into the object. The object being monitored is, for example, industrial equipment, goods, products, or organisms that need to be monitored by at least one measurable physical parameter.

[0005] Typically, such non-contact devices include a memory storage module capable of storing measurement values ​​acquired by the measurement module, an antenna capable of transmitting these measurement values ​​to an interrogator via electromagnetic signals, and a power supply for specifically powering the measurement module.

[0006] Such systems typically include RFID readers or interrogators and contactless devices, which consist of RFID circuitry (or tags) (or multiple circuitry) attached or fixed to the object being tracked. RFID readers usually transmit UHF signals, also known as interrogation signals, to the RFID circuitry. Using UHF signals offers advantages such as high communication speeds and the ability to communicate with a large number of tags simultaneously.

[0007] For this purpose, the non-contact device includes one or more sensors for measuring at least one physical parameter. The sensors may be configured as transducers that convert one physical signal into another, such as converting mechanical strain into electrical energy.

[0008] Many types of sensors are known, such as the strain sensor described by B. Rue, B. Olbrechts, J.-. Raskin, and D. Flandre, “A SOI CMOS smart strain sensor,” IEEE 2011 International SOI Conference, Tempe, AZ, 2011, pp. 1-2. This type of strain sensor can be used to measure the deformation or strain of an object being monitored.

[0009] The RFID tags used in these systems are typically passive tags, meaning they do not contain any batteries or power storage devices. These tags use the power contained in the carrier wave of the reader signal to send a modulated version of the reader signal back to the RFID reader. At least a portion of the power from the interrogation signal is recovered by a power harvesting device to power the tag's components. Passive tags offer the advantages of being lightweight, uncomplicated, and having a long lifespan.

[0010] Passive RFID tags are described, for example, in document FR3015729(A1) or C. Felini et al., “Fully RF Powered UHF-RFID Sensor Platform,” Procedia Engineering 87 (2014) 1346-1349. RFID tags are also known from US20080136619A1, US20130099897A1, US6720866B1, CN104361388A, US9789738B2, or US20100231407A1.

[0011] However, the combined use of UHF interrogation signals and passive tags does have the drawback of a short read distance, such as less than 20 cm (especially when the circuit is connected to the sensor), because the power recovered by the passive tag is limited. In this case, using an external sensor connected to the circuit via an interface can consume most of the power, especially if the sensor includes discrete electronics (or digital components), the interface is a digital interface (e.g., SPI or I2C), and / or the channel used to acquire signals from the external sensor consumes too much power. Furthermore, the read time can be long, for example, lasting more than 500 ms. Additionally, if a digital interface is used, the system, including the circuit and the external sensor connected via the interface, can have a large mass and size. Summary of the Invention

[0012] The object of this invention is to mitigate all or some of the aforementioned disadvantages, specifically, to allow for rapid strain measurement with reduced power consumption. This invention also aims to achieve long readout distances, for example, up to 5 meters, and to provide a non-contact device including external sensors and circuitry connected via a reduced-size interface. Furthermore, this invention aims to be compatible with the EPC UHF Gen2 air interface protocol.

[0013] To this end, the present invention provides a circuit for a passive radio identification tag operating in the UHF band, the circuit being configured to radioly communicate with a reader that transmits a read signal. The circuit is manufactured as a single chip, the single chip including one or more transducers for measuring strain, a first sub-circuit configured to acquire transducer measurements, and a second sub-circuit configured to radioly transmit the acquired measurements to the reader.

[0014] A chip (or die) can be considered as a single integrated circuit and / or a single chip.

[0015] And / or the transducer, the first sub-circuit and the second sub-circuit are integrated in the chip (in the same integrated circuit).

[0016] Therefore, because the transducer is integrated with the first and second sub-circuits in the chip, measurements can be acquired and sent to the reader much faster (e.g., in a period of 1500 μs or less), while reducing power consumption (e.g., 1 μA or less). This allows for an extended reading distance (specifically due to the reduced power consumption), for example, up to 5 meters, and a reduction in the size of the contactless device.

[0017] A transducer can be considered as a strain sensor, such as a piezoresistive type sensor, and / or a transducer can be configured to measure mechanical strain applied to a circuit, and / or a transducer can include at least one strain sensor provided by two transistors sensitive to orthogonal strain, and / or a transducer can include at least one positive current-varying strain sensor and at least one negative current-varying strain sensor, and / or a transducer can include two or more strain sensors connected in series.

[0018] Using quadrature transistors, it is possible to measure the strain experienced by a component in two directions, X and Y, in a plane.

[0019] Specifically, the transducer may include at least one positive current variation strain sensor and at least one negative current variation strain sensor.

[0020] For example, a transducer may include two or more positive current-varying strain sensors and two or more negative current-varying strain sensors connected in series.

[0021] Using strain sensors in series can improve (multiply) the sensitivity of transducers used to measure strain.

[0022] The first subcircuit may include a (first) element configured to supply power current to the transducer. This element may be configured with a bias current and optionally have a predetermined current gain.

[0023] The first sub-circuit may further include: (second) elements configured to perform common-mode current cancellation on the output signal of the transducer or each positive / negative current-varying strain sensor. This allows only the current caused by variations in the transducer signal to be considered, excluding the common-mode current. Therefore, the range of the measurement signal can be increased.

[0024] If the transducer includes a positive current-varying strain sensor and a negative current-varying strain sensor, the first sub-circuit may include a (third) element configured to generate a differential signal between the output signals of the two strain sensors, specifically after the corresponding elimination of the common-mode current. This can also increase the range of the measurement signal.

[0025] The first sub-circuit may include an I / V converter configured to convert the output signal of a transducer or to convert a differential signal.

[0026] An I / V converter can be configured to convert a current signal into a voltage signal.

[0027] The I / V converter can be a passive converter and is configured to generate a differential voltage signal.

[0028] Therefore, the converter allows the action to be performed on a voltage signal rather than the original current signal.

[0029] The first sub-circuit may include an analog-to-digital converter (ADC) configured to digitize transducer measurements, specifically the output signal of an I / V converter. This digitized signal may be received by a command device of the circuit (and / or the second sub-circuit), which may transmit the digitized signal (e.g., via an antenna) to a reader.

[0030] The reader can transmit periodic read signals, including a power recovery phase and a communication phase. Specifically, the second sub-circuit may include: a command device configured to: accumulate power reserves from radio waves during the power recovery phase and communicate with the reader during the communication phase, wherein the power recovery phase includes an acquisition phase during which the circuit supplies power to the transducer and acquires, I / V converts, and digitizes transducer measurements.

[0031] The command equipment can also be configured to send digitized transducer measurements to a reader during the communication phase of the same cycle.

[0032] Because measurements can be acquired, converted, and digitized during the acquisition phase—which occurs during the power recovery phase and therefore before the communication phase, and thus within a single cycle of periodic signal reading—the measurements can be sent directly to the reader during the communication phase, i.e., within the same cycle. This reduces the circuit's response time. Consequently, several external circuits can be read (interrogated) very quickly. For example, objects including the circuitry according to the invention can be placed together in a crate and each can be read very quickly.

[0033] The circuit may also include an interface for connecting (at least) an external analog sensor. This interface may include: an electrical connection configured to connect and supply power to the external analog sensor and acquire analog measurements from the sensor; and an amplifier configured to amplify the signal from the sensor's analog measurements. An analog-to-digital converter (ADC) may be configured to digitize the amplified analog measurements from the sensor. A power recovery phase may include an acquisition phase during which the interface supplies power to the external analog sensor and acquires, amplifies, and digitizes the sensor's measurements.

[0034] The command equipment can also be configured to: during the acquisition phase, power the interface to acquire amplified and digitized measurements, and during the communication phase of the same cycle, send the amplified and digitized measurements to the reader.

[0035] Therefore, due to this interface, analog sensors can be directly connected to the circuit, consuming less power than digital sensors that include additional electronic components / circuits. Furthermore, since the sensor measurements can be acquired, amplified, and digitized during the acquisition phase—which occurs during the power recovery phase and therefore before the communication phase, and thus within a single cycle of periodic signal reading—the measurements can be directly sent to the reader during the communication phase (i.e., within the same cycle). This reduces the circuit's response time. Consequently, several external circuits can be read (interrogated) very quickly. For example, objects including the circuit according to the invention can be placed together in a crate and each can be read very quickly. According to another example, tire pressure can be measured as a vehicle passes through a gate.

[0036] The command equipment can be configured to activate during a startup phase, which precedes the acquisition phase and occurs during the same power recovery phase.

[0037] The power recovery phase may also include an initial power recovery phase preceding the startup phase, during which the circuit is shut off and power reserves are specifically accumulated from radio waves.

[0038] Therefore, reliable startup can be ensured because the accumulated power level is high enough.

[0039] The power recovery phase may also include a first intermediate power recovery phase located between the startup phase and the acquisition phase, during which the circuit is turned off and power reserves are specifically accumulated from radio waves.

[0040] Therefore, reliable measurement can be ensured because the accumulated power level is high enough.

[0041] The power recovery phase may also include a second intermediate power recovery phase, which is located after the acquisition phase and before the communication phase, during which the circuit is turned off and power reserves are specifically accumulated from radio waves.

[0042] Therefore, it can be ensured that the measured values ​​are reliably sent to the reader because the accumulated power level is high enough.

[0043] The command equipment can be optionally configured to provide power to the interface specifically during the acquisition phase.

[0044] Therefore, analog sensors can be powered by the interface. Furthermore, power consumption can be reduced if the interface is activated specifically during the acquisition phase.

[0045] The command equipment can optionally be configured to sequentially power the components of the interface, such as sequentially powering analog sensors, amplifiers, and analog-to-digital converters (ADCs).

[0046] Therefore, since each component is powered only at the moment when a specific measurement needs to be performed, instantaneous power consumption can be reduced.

[0047] Therefore, the command equipment can be configured to provide: firstly, a dedicated electrical connection for powering external analog sensors and acquiring their analog measurements; and then a dedicated analog-to-digital converter (ADC) for digitizing the amplified analog measurements from the sensors.

[0048] After the analog-to-digital converter (ADC) digitizes the measured value and during the acquisition phase, the command device reads the digitized measured value and stores it in memory.

[0049] Therefore, the measured values ​​are ready to be sent to the reader at the start of the communication phase.

[0050] The circuit is compatible with (or communicates according to) the EPC UHF Gen2 air interface protocol, for example.

[0051] Furthermore, the present invention provides a passive radio identification system operating in the UHF band, comprising: a reader configured to transmit periodic read signals, the period of which includes a power recovery phase and a communication phase; and the circuitry described above.

[0052] Furthermore, the present invention provides a method for manufacturing a circuit for a passive radio frequency identification tag operating in the UHF band, the circuit being configured for radio communication with a reader that transmits a read signal, wherein...

[0053] The circuit is fabricated as a single chip, which includes at least one transducer for measuring strain, a first sub-circuit for acquiring the transducer measurements, and a second sub-circuit for radioly transmitting the acquired measurements to a reader.

[0054] The manufactured circuits can also have the aforementioned features within the scope of non-contact devices.

[0055] The features and advantages of the invention will become apparent from the following description, given by way of non-limiting example only and with reference to the accompanying drawings. Attached Figure Description

[0056] Figure 1 This is a schematic diagram of the circuit architecture according to the present invention.

[0057] Figure 2 This is a schematic diagram of the transducer circuit according to the present invention.

[0058] Figure 3 This is a schematic diagram of the power recovery stage according to the present invention, and

[0059] Figure 4 This is a schematic diagram of the ACQ power acquisition stage according to the present invention. Specific Implementation

[0060] Figure 1 This is a schematic diagram of the architecture of circuit 1 according to the present invention. Circuit 1 is an RFID-type circuit operating in the UHF band and can be used as an RFID tag. This circuit is, for example, compatible with the EPC UHF Gen2 air interface protocol (or communicates according to the EPC UHF Gen2 air interface protocol).

[0061] The circuit may take the form of an adhesive tag attached to the object to be monitored, or a chip integrated into the object. The object to be monitored may be, for example, goods, products, or organisms that need to be monitored by at least one measured physical parameter—specifically, mechanical strain (voltage, deformation, or stress) applied to the object and thus to the circuit.

[0062] The circuit is fabricated as a single chip, namely an integrated circuit or "die".

[0063] Circuit 1 operates passively, meaning it does not include any battery or power storage device. However, it uses the power contained in the carrier wave of the reader signal to send a modulated version of the reader signal back to the RFID reader. At least a portion of the power of the interrogation signal is recovered by a power harvesting device to power the components of the circuit. In detail:

[0064] Circuit 1 includes an analog module 2 connected to antenna 21 to recover power received by the antenna via radio waves emitted by an external reader, and to receive and transmit communication signals.

[0065] For this purpose, analog module 2 includes a modulation unit 22 (e.g., for transmitting communication signals). Analog module 2 also includes a demodulation unit 25 (e.g., for receiving communication signals). Furthermore, analog module 2 includes a rectifier unit 23 and a power supply control unit 24 for continuing and / or accumulating power reserves from radio waves during the power recovery phase. The rectifier unit 23 can convert radio power into DC power to power the circuitry. Additionally, the power supply control unit 24 can generate DC current to supply bias current (optionally with a given current gain) to the transducer and optionally also generate a "clean" DC voltage to power interface 4. For example, the accumulated power can be stored in a capacitor (e.g., a capacitor).

[0066] Analog module 2 is connected to digital module 3 (or command device 3). Digital module 3 includes a processor and / or memory storage unit 31 capable of processing data and / or external analog sensors. Additionally, the digital module optionally includes digital interfaces 32, 34, such as SPI or I2C, and / or an interrupt interface 33. Digital module 3 controls analog module 2, for example, by providing it with accumulated power and communicating with a reader via antenna 21. Therefore, the accumulation, consumption, and storage of power are controlled by digital module 3 (see below for details). Figure 2 (Explanation).

[0067] Analog module 2 and digital module 3 can together form a second sub-circuit according to the invention for radioly transmitting transducer measurements to a reader.

[0068] Circuit 1, such as analog module 2, also includes circuitry (or transducer circuitry) 5 for measuring strain. Therefore, the transducer is integrated into the chip of the circuit. The transducer can be a strain sensor implemented using two transistors sensitive to orthogonal strain, such as a piezoresistive strain sensor. The transducer and the (first) sub-circuit for acquiring the transducer measurements will be combined... Figure 2 Provide a detailed description.

[0069] The circuit, or more specifically the (first) sub-circuit, also includes an analog-to-digital converter (ADC) 43 configured to digitize amplified analog transducer measurements. The signal exiting converter 43 is sent to digital module 3 for storage and then to a reader. The converter can be connected to oscillator 28 to receive the clock signal "CLK".

[0070] The circuit may also include other internal analog sensors (e.g., for measuring temperature) connected to converter 43.

[0071] Digital module 3 may also be optionally connected to interface (or interface module) 4. Interface 4 includes an electrical connection 41 configured to connect and supply power to an external analog sensor and acquire analog measurements from the sensor. It also includes an amplifier 42 configured to amplify the signal of the analog measurements from the sensor. Analog-to-digital converter (ADC) 43 is configured to further digitize the amplified analog measurements from the sensor.

[0072] Figure 2 This is a schematic diagram of the transducer circuit according to the present invention.

[0073] like Figure 2 As shown, transducer 51 may include at least one strain sensor implemented by two transistors sensitive to orthogonal strain. Specifically, in Figure 2 In the example, the transducer includes two (or more) positive current variation strain sensors 51c, 51d connected in series and two (or more) negative current variation strain sensors 51a, 51b connected in series.

[0074] Circuit 1, such as analog module 2, includes element 55 for setting a bias current and element 56 for applying a gain to the bias current. These elements 55 and 56 provide the supply current to the transducer. These elements 55 and 56 can together form the first element of the present invention.

[0075] Circuit 1, such as analog module 2, also includes a second element 52 configured to perform common-mode current cancellation on the output signal of transducer 51. For this purpose, the element comprises two sub-elements 52a and 52b. This allows only the current caused by changes in the transducer's signal to be applied, excluding the common-mode current. Therefore, the range of the measured signal can be increased.

[0076] Circuit 1, such as analog module 2, also includes a third element 53 configured to generate a differential signal between the output signals of the two orthogonal strain sensors, specifically after element 52 correspondingly eliminates the common-mode current. This can also increase the range of the measurement signal.

[0077] Circuit 1, such as analog module 2, further includes a current / voltage I / V converter 54 configured to convert the differential output signal of element 53 into a voltage signal. The I / V converter 54 may be a passive converter and is configured to generate a differential voltage signal. Therefore, the converter can act on a voltage signal instead of the original current signal. The output signal of the I / V converter 54 is sent to an analog-to-digital converter (ADC) 43.

[0078] Components 55, 56, 52, 53, I / V converter 54, and analog-to-digital converter (ADC) 43 can together form a first sub-circuit according to the invention configured for acquiring transducer measurements.

[0079] Figure 3 This is a schematic diagram of the power recovery phase according to the present invention. The diagram shows four activities (or four sub-diagrams), with the X-axis indicating time.

[0080] The external reader transmits periodic read signals. One cycle P of the read signal includes a power recovery phase (REC) and a communication phase (COM). During the power recovery phase (REC), power reserves are accumulated from the radio waves of the external reader. The power recovery phase (REC) includes the phases described below.

[0081] As indicated in the “RF_Harvesting” subgraph, the stored power is increased during the initial power recovery phase (e.g., 5 microwatts over 500 microseconds) because no components or cells in the circuit are active, and therefore all power is stored.

[0082] Then, when sufficient power has been stored to allow for reliable operation, digital module 3 is activated during the startup phase (e.g., consuming 6 microwatts over 250 microseconds). Simultaneously, due to this operation of digital module 3, the stored power is reduced.

[0083] Therefore, after the startup phase, the power recovery phase includes a first phase of recovering intermediate power, in which the stored power is increased again (e.g., to 5 microwatts within 100 microseconds) because no components or units in the circuit are active, and therefore all power is stored.

[0084] Subsequently, when sufficient power is stored to allow reliable operation, transducer measurements 51 are acquired and digitized during the acquisition phase (“acquisition”) (and optionally, interface 4 powers an external analog sensor to acquire, amplify, and digitize the sensor’s measurements) (e.g., 6 microwatts consumed over 250 microseconds). Simultaneously, the stored power is reduced due to this operation of the digital module 3.

[0085] Therefore, after the acquisition phase, the power recovery phase includes a second phase that recovers intermediate power, in which the stored power is increased again (e.g., to 5 microwatts within 100 microseconds) because no components or units in the circuit are active, and thus all power is stored.

[0086] Afterwards (or after another predefined time period), the power recovery phase can be completed, and the communication phase (COM) can begin. During the communication phase, i.e., within the same cycle, the measured values ​​are transmitted to an external reader.

[0087] Figure 4 This is a schematic diagram of the ACQ (Accumulation and Acquisition) phase according to the present invention. The diagram indicates eight activities (or eight sub-diagrams), with the X-axis indicating time. During the ACQ phase, the components of interface 4 are sequentially powered. As indicated in the “SENSOR_EN” sub-diagram, firstly, only the transducer 51 (and optionally, the electrical connection, and therefore the external analog sensor) is powered (e.g., for 1 microsecond), and the signal generated by the transducer (and optionally, the sensor signal) is read and sampled. Afterwards, as an optional phase, amplifier 42 is provided separately to amplify the signal of the analog measurement value from the sensor (see “AMP_EN” sub-diagram). Next, only the analog-to-digital converter (ADC) 43 is powered to digitize the analog measurement value (see “ADC_EN” sub-diagram). After the ADC digitizes the measurement value, and still preferably during the acquisition phase, processor 31 reads and stores the digitized measurement value, thus provided by digital module 3 (see “DATA_RDY” sub-diagram).

[0088] Because of this sequential operation, the total power consumption for acquiring amplified and digitized measurements can be reduced, for example, to 1 microwatt. Therefore, the acquisition and transmission of measurements can be completed within a single cycle of the reader's signal.

Claims

1. A single chip, comprising: Circuitry for a passive radio identification tag configured to operate in the UHF band, the circuitry being configured to radio communicate with a reader that transmits a read signal, and At least one transducer, including at least one mechanical strain sensor for measuring strain; a first sub-circuit configured to acquire transducer measurements of the transducer; And a second sub-circuit configured to wirelessly transmit the acquired transducer measurements to the reader, wherein the transducer, the first sub-circuit, and the second sub-circuit are integrated into the single chip of the same integrated circuit.

2. The chip of claim 1, wherein, At least one of the following is true: The transducer is a piezoresistive strain sensor, or the transducer comprises at least one strain sensor implemented by two transistors sensitive to orthogonal strain. The transducer includes at least one positive current variation strain sensor and at least one negative current variation strain sensor, and The transducer includes two or more strain sensors connected in series.

3. The chip according to claim 1, wherein, The first sub-circuit includes an element configured to provide power current to the transducer.

4. The chip according to claim 1, wherein, The first sub-circuit includes an element configured to perform common-mode current cancellation on the output signal of the transducer.

5. The chip according to claim 1, wherein, The transducer includes a positive current variation strain sensor and a negative current variation strain sensor, and the first sub-circuit includes an element configured to generate a differential signal between the output signals of the two positive and negative strain sensors after the corresponding elimination of the common-mode current.

6. The chip according to claim 5, wherein, The first sub-circuit includes an I / V converter configured to convert the output signal of the transducer or to convert the differential signal.

7. The chip according to claim 6, wherein, The I / V converter is configured to convert a current signal into a voltage signal, or the I / V converter is a passive converter and is configured to generate a differential voltage signal.

8. The chip according to claim 6, wherein, The first sub-circuit includes an analog-to-digital converter (ADC) configured to digitize the transducer measurement, wherein the transducer measurement is the output signal of the I / V converter.

9. The chip according to claim 1, wherein: The reader transmits periodic read signals, which include a power recovery phase and a communication phase. The second sub-circuit of the circuit includes a command device configured to: accumulate power reserves from radio waves during the power recovery phase and communicate with the reader during the communication phase. The power recovery phase includes a data acquisition phase during which the circuit supplies power to the transducer and acquires, I / V converts, and digitizes the transducer measurements.

10. The chip according to claim 9, wherein, The command equipment is also configured to send digitized transducer measurements to the reader during the communication phase of the same cycle.

11. The chip according to claim 10, wherein, The circuit further includes: an interface for connecting an external analog sensor, the interface comprising: An electrical connection is configured to: connect to the external analog sensor and supply power to the external analog sensor, and acquire analog measurement values ​​from the external analog sensor; and An amplifier is configured to amplify the signal of the analog measurement value from the external analog sensor, wherein, The analog-to-digital converter (ADC) is configured to digitize the amplified analog measurements from the external analog sensor, and The command equipment is also configured to: During the acquisition phase, the interface is powered to acquire amplified and digitized measurements from the external analog sensor, and During the communication phase of the same cycle, the digitized measurement values ​​are sent to the reader.

12. The chip according to claim 9, wherein, The command equipment is configured to activate during a startup phase, which precedes the acquisition phase and occurs during the same power recovery phase.

13. The chip according to claim 12, wherein, The power recovery phase also includes an initial power recovery phase preceding the startup phase, during which the circuit is shut down and power reserves are specifically accumulated from the radio waves.

14. The chip according to claim 12, wherein, The power recovery phase is a first intermediate power recovery phase located between the startup phase and the acquisition phase. During the first intermediate power recovery phase, the circuit is turned off and power is specifically accumulated from the radio waves.

15. The chip according to claim 10, wherein, The power recovery phase is a second intermediate power recovery phase that occurs after the acquisition phase and before the communication phase. During the second intermediate power recovery phase, the circuit is turned off and power is specifically accumulated from the radio waves.

16. The chip according to claim 11, wherein, The command equipment is configured to specifically power the interface during the acquisition phase.

17. A passive radio identification system configured to operate in the ultra-high frequency (UHF) band, comprising: The reader is configured to transmit periodic read signals, the period of which includes a power recovery phase and a communication phase, and The single chip according to claim 1.

18. A method of manufacturing circuitry for a passive radio frequency identification tag configured to operate in the ultra-high frequency (UHF) band, the circuitry being configured to radioly communicate with a reader transmitting a readout signal, the method comprising: A circuit is provided as a single chip, the single chip including at least one transducer for measuring strain, a first sub-circuit for acquiring transducer measurements of the transducer, and a second sub-circuit for radioly transmitting the acquired transducer measurements to the reader, wherein the transducer, the first sub-circuit, and the second sub-circuit are integrated into the single chip in the same integrated circuit.

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