Frequency conversion sensing circuit, wireless sensing circuit, device, system and method

Abstract

The invention discloses a frequency conversion sensing circuit, a wireless sensing circuit, a device, a system and a method. According to the invention, the compensation data is obtained by using the frequency change of the frequency conversion signal of the frequency conversion module in the background noise state, and the compensation data is used as the background noise data caused by the external environment change, so that the target sensing data can be obtained by using the difference between the nominal sensing data and the compensation data. On one hand, a frequency conversion signal of the frequency conversion module can be modulated through coded data, digital signal frequency conversion transmission is achieved, and the anti-interference capacity is improved; and on the other hand, the periodic on-off of the returned frequency conversion signal realizes the transmission of the identity coding data, the change of the carrier frequency represents the nominal sensing data and the background noise data, and the accurate target sensing data can be obtained by collecting the frequency change of the frequency conversion signal under the two working states within a certain time.

Description

Technical Field

[0001] The present invention relates to the field of wireless communications, and more specifically, to a frequency conversion sensing circuit, a wireless sensing circuit, a device, a system and a method. Background Art

[0002] Existing passive wireless frequency conversion sensors usually use frequency division addressing technology. When there are multiple wireless sensor terminals within the communication range of the transceiver, there is a problem that the communication bandwidth can only accommodate a limited number of wireless sensor terminals. In addition, when the wireless sensor terminal is working, the returned sensor data contains both the target sensor quantity and the external environment interference component. For occasions with harsh environments, the accuracy of the wireless sensor terminal is greatly challenged.

[0003] In the prior art, additional reference elements are often added to obtain compensation data for the external environment. Since the reference element is not part of the wireless sensor terminal circuit, the compensation effect is limited and the complexity and cost of the wireless sensor terminal are increased. Therefore, how to improve the capacity of the wireless sensor terminal within the communication coverage of the transceiver and the accuracy of wireless sensing is a problem to be solved in the passive Internet of Things technology. Summary of the invention

[0004] The present invention provides a variable frequency sensing circuit, a wireless sensing circuit, a device, a system and a method, in the hope of solving at least one technical problem existing in the prior art.

[0005] One aspect of the present invention provides a frequency conversion sensing circuit, comprising a frequency conversion module and a sensing modulation module; The frequency conversion module is used to convert a first radio frequency signal having a first frequency into a frequency conversion signal having a frequency different from the first frequency; The sensing modulation module is electrically connected to the frequency conversion module, and the sensing modulation module can be switched between a non-sensing state and a sensing state. When the sensing modulation module is in the non-sensing state, the frequency conversion module outputs a first frequency conversion signal containing background noise data; When the sensing modulation module is in the sensing state, the frequency conversion module outputs a second frequency conversion signal including background noise data and target sensing data.

[0006] The present application utilizes the frequency change of the frequency conversion signal when the frequency conversion module is in the background noise state (at this time, the frequency change of the frequency conversion signal of the frequency conversion module is only affected by the change of the external environment, such as f m11 becomes f m12 , whose variation represents the background noise data caused by the change of the external environment) to obtain compensation data, which is used as the background noise data caused by the change of the external environment, so that the target sensing data can be obtained by using the difference between the aforementioned nominal sensing data and the compensation data or the background noise data.

[0007] The advantages of the present invention are that, on the one hand, the coded data can be used to modulate the frequency conversion signal of the frequency conversion module, thereby realizing the frequency conversion transmission of the digital signal and improving the anti-interference ability of the frequency conversion sensing circuit; on the other hand, the periodic on-off of the returned frequency conversion signal realizes the transmission of the identity coded data, and at the same time, the change of the carrier frequency represents the nominal sensing data and the background noise data. By collecting the frequency changes of the frequency conversion signal under two working states within a certain period of time, accurate target sensing data can be obtained.

[0008] In other words, the present invention realizes the simultaneous loading of amplitude modulation and frequency modulation, amplitude modulation realizes the transmission of digitally encoded identity encoded data, and frequency modulation realizes the transmission of nominal sensing data and background noise data, which has higher sensing accuracy and precision than analog sensing with frequency division addressing.

[0009] A further technical solution is that the sensing modulation module includes a modulation element, a first resonance unit and a second resonance unit; The modulation element includes at least three ports, a first modulation port, a second modulation port and a third modulation port, the first modulation port receives a first radio frequency signal; the first resonance unit is electrically connected to the second modulation port; and the first end of the second resonance unit is electrically connected to the third modulation port.

[0010] Driven by the first RF signal, the frequency conversion module generates a frequency conversion signal with a frequency different from the first frequency. Its working principle is that the modulation element modulates the first frequency ( f 1) The first RF signal is energy dispersed to obtain a broadband noise signal, the broadband noise signal is output from the second modulation port of the modulation element to the first resonance unit, the first resonance unit re-converges the broadband noise signal to obtain a second RF signal, and the second RF signal is fed into the second resonance unit after passing through the modulation element.

[0011] The second resonant unit performs secondary frequency selection according to the fed second RF signal to generate a stable second resonant frequency ( f r2 ) and feed the oscillation signal of the second resonant frequency into the modulation element to be combined with the oscillation signal of the first frequency ( f 1) is mixed with the first RF signal to obtain a signal with a frequency ( f m ) is different from the mixing signal of the first frequency, wherein, f m = f 1±n∙ f r2 , n is a natural number.

[0012] The sensing modulation module comprises a first switch element and a sensing unit, wherein a first end of the first switch element is electrically connected to the sensing unit, and a second end thereof is grounded; The second end of the first resonance unit or the second end of the second resonance unit is electrically connected to the first end of the first switch element and the sensing unit.

[0013] A further technical solution is that the first resonance unit is one of a passive piezoelectric resonator, a parallel LC resonance circuit or a series LC resonance circuit; the second resonance unit is one of a passive piezoelectric resonator, a parallel LC resonance circuit, a series LC resonance circuit, an RF open circuit or an RF short circuit.

[0014] A further technical solution is that the passive piezoelectric resonator includes at least one of a crystal resonator, a ceramic resonator, a surface acoustic wave piezoelectric resonator or a MEMS piezoelectric resonator.

[0015] A further technical solution is that the modulation element includes a transistor with a heterojunction.

[0016] A further technical solution is that the modulation element includes a heterojunction bipolar transistor or a field effect transistor.

[0017] A further technical solution is that the field effect transistor includes one of a metal oxide semiconductor field effect transistor, a two-dimensional electron gas transistor or a high electron mobility transistor.

[0018] A further technical solution is that the first switch element includes one of a diode, a metal oxide semiconductor field effect transistor, a bipolar junction transistor or an insulated gate bipolar transistor.

[0019] The present invention also provides a wireless sensor circuit, comprising an antenna module, a control module, and the frequency conversion sensor circuit as described above; The frequency conversion sensing circuit is electrically connected to the control module and the antenna module respectively; The antenna module is configured to receive a first radio frequency signal having a first frequency in free space, and send a frequency-converting signal having a frequency different from the first frequency into the free space; The control module is configured to generate a working instruction for controlling the variable frequency sensing circuit based on the identity code data; The frequency conversion sensing circuit responds to the working instruction and outputs a first frequency conversion signal or a second frequency conversion signal.

[0020] A further technical solution is that the control module includes one of the following solutions: Energy conversion circuit and control circuit; or includes energy conversion circuit, energy management circuit and control circuit; or includes energy conversion circuit, demodulation circuit and control circuit; or includes energy conversion circuit, energy management circuit, demodulation circuit and control circuit; or includes energy conversion circuit, demodulation circuit, storage circuit and control circuit; or includes energy conversion circuit, demodulation circuit, storage circuit and control circuit.

[0021] The present invention further provides a wireless sensor device, comprising a packaging shell and the wireless sensor circuit as described above, wherein the wireless sensor circuit is fully or partially arranged in the packaging shell.

[0022] The present invention also provides a wireless sensing system, comprising a transceiver and a plurality of wireless sensing devices as described above; The transceiver is used to send a first frequency radio frequency signal to the wireless sensor device, and receive a frequency conversion signal having a frequency different from the first frequency returned by the wireless sensor device that meets the preset communication rules; The frequency conversion signal may carry identity coding data, nominal sensing data and background noise data.

[0023] The present invention also provides a wireless sensing method, comprising the following steps: S1, the transceiver sends a first radio frequency signal having a first frequency; S2, the wireless sensor device receives a first radio frequency signal having a first frequency, and returns a modulated frequency-converted signal to the transceiver device; S3, the transceiver receives and analyzes the modulated frequency conversion signal to obtain identity coding data, nominal sensing data and background noise data; wherein the target sensing data is obtained according to the nominal sensing data and the background noise data.

[0024] Compared with the prior art, the present invention has at least the following beneficial effects: in this solution, in the same variable frequency sensing circuit, the nominal sensing data and the background noise data as compensation data are respectively extracted in two states using the identity coding data. Without introducing other unnecessary components, the background noise influence of the environment in which the variable frequency sensing circuit is located can be quantitatively calculated, thereby obtaining clean target sensing data, and better compensating for the influence of the external environment on the wireless sensing device.

[0025] In this scheme, the frequency conversion module is a working component involved in both working states (i.e., sensing state and non-sensing state) of the frequency conversion sensing circuit. This scheme cleverly uses the modulation characteristics of identity coding data to extract the degree to which the frequency conversion module is affected by the external environment. Compared with the prior art that uses auxiliary reference elements as compensation data for the influence of the external environment, this scheme has many advantages such as high fidelity of target sensing data, good compensation effect, simple structure and low cost.

[0026] In this solution, the digitally encoded identity signal and sensor data are modulated onto the variable frequency signal of the variable frequency sensor module, realizing passive wireless digital signal variable frequency transmission, which can greatly increase the number of wireless sensor devices installed within the communication range of the transceiver, and overcome the problems of limited number of wireless sensor devices installed on the same transceiver and complex debugging under the hetero-frequency communication system of transceivers in the prior art.

[0027] In this solution, by transmitting the frequency conversion sensor signal back in a digitally encoded manner, many defects of analog frequency conversion sensor signals, such as weak wireless transmission anti-interference ability, low accuracy, low precision, and poor robustness, can be overcome. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the frequency conversion sensing circuit principle of the present invention; Figure 2 This is a schematic diagram of the output signal of the frequency conversion sensor circuit; Figure 3 A schematic diagram of a frequency conversion module framework according to an embodiment; Figure 4 A schematic diagram of a variable frequency sensing circuit including a passive piezoelectric resonator according to an embodiment; Figure 5 A schematic diagram of a variable frequency sensing circuit including a series LC resonant circuit according to another embodiment; Figure 6 is a schematic diagram of a wireless sensor circuit according to an embodiment; Figure 7 FIG. 4 is a schematic diagram of a wireless sensing system according to an embodiment of the present invention.

[0029] In the figure, 10-frequency conversion sensing circuit, 11-antenna module, 12-control module, 13-frequency conversion module, 131-modulation element, 132-first resonance unit, 1321-first series capacitor, 1322-first series inductor, 133-second resonance unit, 1331-passive piezoelectric resonator, 14-sensing modulation module, 141-first switching element, 142-sensing unit, 100-wireless sensing device, 200-transceiver. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] Figure 1 A frequency conversion sensing circuit 10 is provided, comprising a frequency conversion module 13 and a sensing modulation module 14, wherein the frequency conversion module 13 is used to convert a first frequency ( f1) The first RF signal is converted to have a frequency ( f m ) is different from the frequency conversion signal of the first frequency, and the sensing modulation module 14 is controlled by the identity coding data and is divided into a background noise state and a modulation state. Since in the subsequent embodiments, the sensing modulation module 14 includes a sensing unit 142, the background noise state and the modulation state correspond to the non-sensing state and the sensing state respectively, so that the identity coding data and the sensing data are loaded onto the frequency conversion signal; the frequency conversion sensing circuit 10 extracts the nominal sensing data according to the frequency change of the frequency conversion signal in the sensing state, and extracts the compensation data according to the frequency change of the frequency conversion signal in the non-sensing state.

[0032] For example, Figure 2 The output schematic diagram of the first modulation port of the variable frequency sensing circuit of an embodiment is shown, in which the horizontal axis is time and the vertical axis is the working state of the sensing modulation module 14. The sensing modulation module 14 includes two working states, namely the sensing state V1 and the non-sensing state V2. Accordingly, the variable frequency sensing circuit outputs a first variable frequency signal and a second variable frequency signal, wherein the first variable frequency signal includes background noise data, and the second variable frequency signal includes both background noise data and target sensing data, namely nominal sensing data. In other words, the nominal sensing data can be extracted according to the second variable frequency signal, and the background noise data can be extracted according to the first variable frequency signal as compensation data, and the target sensing data can be obtained according to the nominal sensing data and the compensation data. Within a data transmission cycle, the identity coding data can be extracted according to the combination of the sensing state V1 and the non-sensing state V2 of the sensing modulation module 14, and the nominal sensing data can be obtained according to the change in the frequency of the variable frequency signal of the frequency conversion module 13 in the sensing state. For example, when the frequency of the variable frequency signal changes from V1 to V2 due to changes in the target sensing quantity and the external environment, the nominal sensing data can be obtained. f m21 becomes f m22 , the nominal sensing data can be obtained according to the pre-mapped relationship between frequency and sensing quantity. It should be understood that the nominal sensing data includes both the target sensing data and the background noise data caused by the change of the external environment. The worse the environment in which the frequency conversion sensing circuit is located, the lower the accuracy of the above nominal sensing data; therefore, the present application utilizes the frequency change of the frequency conversion signal in the non-sensing state of the frequency conversion module 13 (corresponding to the non-sensing state of the sensor modulation module 14) (at this time, the frequency change of the frequency conversion signal of the frequency conversion module 13 is only affected by the change of the external environment, for example, from f m11 becomes f m12, whose variation represents the background noise data caused by the change of the external environment) to obtain compensation data, which is used as the background noise data caused by the change of the external environment, so that the target sensor data can be obtained by using the difference between the aforementioned nominal sensor data and the compensation data. The transmission method modulates the digitally encoded identity signal and sensor data onto the variable frequency signal of the variable frequency sensor module, realizing passive wireless digital signal variable frequency transmission.

[0033] The frequency conversion module 13 can be implemented in a variety of ways. Several implementations based on the frequency mixing process are introduced below.

[0034] Figure 3 A frequency conversion module 13 is provided, and the frequency conversion module 13 includes a modulation element 131, a first resonance unit 132, and a second resonance unit 133. The modulation element 131 includes at least three ports, namely a first modulation port, a second modulation port, and a third modulation port, the first modulation port receives a first radio frequency signal; the first resonance unit 132 is electrically connected to the second modulation port; and the first end of the second resonance unit 133 is electrically connected to the third modulation port.

[0035] In this embodiment, the first modulation port is used to input a first frequency ( f 1) a first radio frequency signal, and outputting a frequency conversion signal having a frequency different from the first frequency.

[0036] The modulation element 131 includes a transistor having a two-dimensional electron gas, wherein the drain of the transistor serves as a first modulation port, the source serves as a second modulation port, and the gate serves as a third modulation port.

[0037] The second resonant unit 133 is used as a frequency selection element. When the frequency conversion module 13 meets the condition of generating a frequency conversion signal, the frequency conversion module 13 starts to work immediately under the drive of the first RF signal, and generates a frequency conversion signal with a frequency different from the first frequency. Specifically, in this process, the modulation element 131 modulates the first frequency ( f 1) obtains a broadband noise signal by dispersing the energy of the first RF signal, which is output from the second modulation port of the modulation element 131 to the first resonance unit 132. The first resonance unit 132 re-converges the broadband noise signal to obtain a second RF signal, and feeds the second RF signal to the second resonance unit 133 after passing through the modulation element 131. The second resonance unit 133 performs secondary frequency selection according to the fed second RF signal to generate a stable second resonance frequency ( f r2 ) and feeds the oscillation signal of the second resonant frequency into the modulation element 131 to be combined with the oscillation signal of the first frequency ( f 1) is mixed with the first RF signal to obtain a signal with a frequency ( f m) is different from the mixing signal of the first frequency, wherein, f m = f 1±n∙ f r2 , n is a natural number.

[0038] Figure 4 A frequency conversion sensing circuit 10 is provided, comprising a frequency conversion module 13 and a sensing modulation module 14 ; the frequency conversion module 13 is connected to the sensing modulation module 14 .

[0039] Specifically, the frequency conversion module 13 refers to Figure 3 The frequency conversion module 13 shown; the sensing modulation module 14 is electrically connected to the second end of the second resonance unit 133; the sensing modulation module 14 includes a first switching element 141 and a sensing unit 142, the first end of the first switching element 141 is electrically connected to the sensing unit 142, and the second end thereof is grounded; the second resonance unit 133 includes a passive piezoelectric resonator 1331, the first end of the passive piezoelectric resonator 1331 is electrically connected to the third modulation port, and the second end thereof is electrically connected to the sensing unit 142 and the first end of the first switching element 141.

[0040] Its working principle is that the first switch element 141 works in response to the working instruction based on the identity code data, performs the first operation and is in the sensing state when receiving the first working instruction, and performs the second operation and is in the non-sensing state when receiving the second working instruction. In this embodiment, the first working instruction is an opening instruction, that is, the first switch element 141 is in the opening state after responding to the first working instruction, and the sensing state corresponds to the first switch element 141 being in the opening state; the second working instruction is a closing instruction, that is, the first switch element 141 is in the closing state after responding to the second working instruction, and the non-sensing state corresponds to the first switch element 141 being in the closing state. When the first switch element 141 is in a closed state, the frequency conversion module 13 is in a non-sensing state, specifically, the sensor unit 142 cannot work, and the frequency conversion signal frequency output by the frequency conversion module 13 is only affected by the external environment, and the frequency conversion signal data only includes background noise data; when the first switch element 141 is in an open state, the frequency conversion module 13 is in a sensing state, specifically, the sensor unit 142 can work, and the sensor unit 142 and the external environment affect the frequency conversion signal frequency output by the frequency conversion module 13, and the frequency conversion signal frequency includes both target sensing data and background noise data. By collecting the frequency conversion signal data under the two working states of the frequency conversion sensing circuit, the nominal sensing data and the background noise data can be obtained respectively.

[0041] Figure 5Another variable frequency sensing circuit 10 is provided, comprising a frequency conversion module 13 and a sensing modulation module 14; the sensing modulation module 14 is electrically connected to the second end of the first resonance unit 132. The sensing modulation module 14 comprises a first switch element 141 and a sensing unit 142, wherein the first end of the first switch element 141 is electrically connected to the sensing unit 142, and the second end thereof is grounded; the first resonance unit 132 adopts a series LC circuit, comprising a first series capacitor 1321 and a first series inductor 1322, wherein the first end of the first series capacitor 1321 is electrically connected to the second modulation port, and the second end thereof is electrically connected to the first end of the first series inductor 1322, and the second end of the first series inductor 1322 is electrically connected to the first end of the first switch element 141 and the sensing unit 142.

[0042] In this embodiment, the modulation element 131 is a high electron mobility transistor, and the drain of the transistor serves as the first modulation port, the source serves as the second modulation port, and the gate serves as the third modulation port; the second resonance unit 133 includes a passive piezoelectric resonator 1331 whose second end is grounded, and the first end of the passive piezoelectric resonator 1331 is electrically connected to the third modulation port.

[0043] The working principle is that the first switch element 141 works in response to the working instruction based on the identity code data, performs the first operation and is in the sensing state when receiving the first working instruction, and performs the second operation and is in the non-sensing state when receiving the second working instruction. In this embodiment, the first working instruction is an opening instruction, that is, the first switch element 141 is in the opening state after responding to the first working instruction, and the sensing state corresponds to the first switch element 141 being in the opening state; the second working instruction is a closing instruction, that is, the first switch element 141 is in the closing state after responding to the second working instruction, and the non-sensing state corresponds to the first switch element 141 being in the closing state. When the first switch element 141 is in a closed state, the frequency conversion module 13 is in a non-sensing state, specifically, the sensor unit 142 cannot work, and the frequency conversion signal frequency output by the frequency conversion module 13 is only affected by the external environment, and the frequency conversion signal data only includes background noise data; when the first switch element 141 is in an open state, the frequency conversion module 13 is in a sensing state, specifically, the sensor unit 142 can work, and the sensor unit 142 and the external environment affect the frequency conversion signal frequency output by the frequency conversion module 13, and the frequency conversion signal frequency includes both target sensing data and background noise data. By collecting the frequency conversion signal data under the two working states of the frequency conversion sensing circuit, the nominal sensing data and the background noise data can be obtained respectively.

[0044] It should be understood that in any of the foregoing embodiments, the first resonant unit 132 and the second resonant unit 133 may also adopt other circuits. As an alternative, the first resonant unit 132 may be a passive piezoelectric resonator, a parallel LC resonant circuit, or a series LC resonant circuit; the second resonant unit 133 may be a passive piezoelectric resonator, a parallel LC resonant circuit, a series LC resonant circuit, an RF open circuit, or an RF short circuit.

[0045] In any of the above embodiments, the modulation element 131 may be a transistor with a heterojunction, such as a heterojunction bipolar transistor, a field effect transistor (FET), etc. The FET may be a metal oxide semiconductor field effect transistor (MOSFET), a two-dimensional electron gas transistor, or a high electron mobility transistor (HEMT).

[0046] In any of the above embodiments, the modulation element 131 is a transistor with a two-dimensional electron gas, which includes at least three ports, wherein the drain of the transistor serves as a first modulation port, the source serves as a second modulation port, and the gate serves as a third modulation port.

[0047] In any of the above embodiments, the modulation element 131 may be a two-dimensional electron gas transistor, which includes at least three ports, wherein the first modulation port is a source, the second modulation port is a drain, and the third modulation port is a gate.

[0048] In any of the aforementioned embodiments, the modulation element 131 is a transistor with high electron mobility, which includes at least three ports, wherein the drain of the transistor serves as the first modulation port, the source serves as the second modulation port, and the gate serves as the third modulation port.

[0049] In any of the above embodiments, the modulation element 131 may be a metal oxide semiconductor field effect transistor, which includes at least three ports, wherein the first modulation port is a drain, the second modulation port is a source, and the third modulation port is a gate.

[0050] In any of the above embodiments, the modulation element 131 is a metal oxide semiconductor field effect transistor, which includes at least three ports, wherein the first modulation port is a source, the second modulation port is a drain, and the third modulation port is a gate.

[0051] In any of the foregoing embodiments, the modulation element 131 may be a high electron mobility transistor, which includes at least three ports, wherein the first modulation port is a drain, the second modulation port is a source, and the third modulation port is a gate.

[0052] In any of the foregoing embodiments, the modulation element 131 may be a high electron mobility transistor, which includes at least three ports, wherein the first modulation port is a source, the second modulation port is a drain, and the third modulation port is a gate.

[0053] In any of the foregoing embodiments, the first switch element 141 may include any switch element capable of implementing the operation of passing and blocking the line RF signal, including but not limited to a diode, a metal oxide semiconductor field effect transistor (MOSFET), a bipolar junction transistor (BJT), or an insulated gate bipolar transistor (IGBT).

[0054] In any of the foregoing embodiments, the passive piezoelectric resonator includes but is not limited to a crystal resonator, a ceramic resonator, a surface acoustic wave piezoelectric resonator or a MEMS piezoelectric resonator.

[0055] In any of the aforementioned embodiments, the frequency conversion module 13 can adopt an input-output single-port structure (i.e., the first RF signal and the frequency conversion signal share the same port), or an input-output different-port structure (for example, the first RF signal is input from the first modulation port of the modulation element, and the frequency conversion signal is output from another port electrically connected to the first modulation port, or from another port electrically connected to the second modulation port, or from another port electrically connected to the third modulation port).

[0056] It should be noted that the capacitors appearing in the aforementioned embodiments may be either a single real capacitor or an equivalent capacitor, such as an equivalent capacitor obtained by connecting two independent real capacitors in series, or an equivalent capacitor obtained by other circuit forms. Similarly, the capacitors appearing in the aforementioned embodiments may be either a single real capacitor or an equivalent capacitor, such as an equivalent capacitor obtained by connecting two independent real capacitors in parallel, or an equivalent capacitor obtained by other circuit forms. Unless otherwise specified, the capacitors and capacitors appearing in the following text have the same meanings and will not be described one by one.

[0057] The present invention also provides a wireless sensing circuit, such as Figure 6 As shown, it includes an antenna module 11, a control module 12, and the frequency conversion sensing circuit 10 described in any of the above embodiments, and the frequency conversion sensing circuit 10 is electrically connected to the control module 12 and the antenna module 11 respectively.

[0058] The antenna module 11 is configured to receive a first frequency ( f 1) a first radio frequency signal, and sending a frequency-converted signal having a frequency different from the first frequency into free space.

[0059] The control module 12 is configured to generate a working instruction for controlling the variable frequency sensing circuit 10 based on the identity code data.

[0060] The frequency conversion sensing circuit 10 modulates the frequency conversion signal in response to the aforementioned working instruction.

[0061] Specifically, the variable frequency sensing circuit 10 performs corresponding operations according to the working instructions issued by the control module 12. For example, when receiving the first working instruction, the first operation is performed and the circuit is in the sensing state, and when receiving the second working instruction, the second operation is performed and the circuit is in the non-sensing state. When the variable frequency sensing circuit 10 is in the sensing state, the variable frequency signal corresponding to the nominal sensing data is sent to the antenna module 11; when the variable frequency sensing circuit 10 is in the non-sensing state, the variable frequency signal corresponding to the background noise data is sent to the antenna module 11.

[0062] The control module 12 can be any passive or low-power control device or apparatus that can generate a digital coded signal, including but not limited to a control device or apparatus that works based on ambient energy; wherein the ambient energy includes but is not limited to radio frequency energy, light energy, heat energy, temperature difference energy, and vibration energy in free space. It is understandable that the specific form of the control module 12 is diverse and can be configured according to the application scenario requirements. For example, it can include an energy conversion circuit and a control circuit; or include an energy conversion circuit, an energy management circuit, and a control circuit; or include an energy conversion circuit, a demodulation circuit, and a control circuit; or include an energy conversion circuit, an energy management circuit, a demodulation circuit, and a control circuit; or include an energy conversion circuit, a demodulation circuit, a storage circuit, and a control circuit; or include an energy conversion circuit, an energy management circuit, a demodulation circuit, a storage circuit, and a control circuit.

[0063] When working, the remote transceiver sends a radio frequency signal with a first frequency, i.e., a first radio frequency signal, and the antenna module 11 receives the first radio frequency signal in the free space and transmits the first radio frequency signal to the frequency conversion sensing circuit 10; the frequency conversion sensing circuit 10 works under the control of the control module 12, and sends a frequency conversion signal corresponding to the nominal sensing data to the antenna module 11 when the frequency conversion sensing circuit 10 is in the sensing state; and sends a frequency conversion signal corresponding to the background noise data to the antenna module 11 when the frequency conversion sensing circuit 10 is in the non-sensing state. The frequency conversion signal is coupled and output into the free space through the antenna module 11, and the remote transceiver receives the modulated frequency conversion signal and parses it to obtain the identity coding data, nominal sensing data, and compensation data of the corresponding wireless sensing circuit.

[0064] In principle, the first radio frequency signal may have any radio frequency signal of a suitable first frequency, and the first frequency may be an unlicensed frequency band open to industrial, scientific and medical institutions, or a wireless communication authorized frequency band, such as a 5G NR communication frequency band. Exemplarily, the first frequency includes but is not limited to 125KHz, 13.56MHz, 433MHz, 800MHz, 900MHz, 950MHz, 2.4GHz or 5.8GHz, without specific limitation.

[0065] The antenna module 11 may be any antenna object that can achieve efficient transmission and reception of heterodyne communications.

[0066] In some embodiments, the control module 12 includes a conventional RFID chip, which receives a radio frequency signal (e.g., a first radio frequency signal) in free space and converts the first radio frequency signal into direct current. Other power-consuming components in the RFID chip, such as a demodulation circuit, a storage circuit, and a microcontroller, operate under the function of direct current. It is configured to store identity coding data internally and operate according to a pre-agreed communication strategy. The aforementioned preset communication rules can be common RFID communication rules, such as the anti-collision method described in the prior patent application CN200910095463.X, and the specific communication rules are not limited.

[0067] It should be understood that the energy conversion circuit varies according to the environmental energy used. When the environmental energy is radio frequency energy, the energy conversion circuit can be any suitable circuit that converts radio frequency signals into direct current, including but not limited to a diode rectifier circuit; when the environmental energy is light energy, the energy conversion circuit can be any suitable circuit that converts light energy into direct current, including but not limited to a solar panel or a photovoltaic panel.

[0068] The present invention also provides a wireless sensor device, which includes a packaging shell and the wireless sensor circuit disclosed in any of the above embodiments. The wireless sensor circuit is fully or partially arranged in the packaging shell, and the packaging shell is used to protect the wireless sensor circuit to improve the mechanical performance, environmental performance and service life of the wireless sensor circuit.

[0069] In some embodiments, the wireless sensor circuit is entirely disposed on the packaging shell, and at least the position on the packaging shell corresponding to the antenna module 11 is made of a wave-transmitting material.

[0070] In some implementations, the antenna module 11 of the wireless sensor circuit is disposed outside the package shell, and other modules are disposed inside the package shell. A communication interface electrically connected to the antenna module 11 is disposed on the package shell.

[0071] The present invention also provides a wireless sensing system, such as Figure 7As shown, it includes a transceiver 200 and several wireless sensor devices 100 disclosed in the aforementioned embodiments; The transceiver 200 is used to send a first frequency ( f 1) A radio frequency signal, and receiving a frequency conversion signal having a frequency different from a first frequency and returned by a wireless sensor device 100 that meets a preset communication rule.

[0072] The frequency conversion signal may carry identity coding data, nominal sensing data and background noise data.

[0073] Those skilled in the art should understand that the aforementioned preset communication rules may be common RFID communication rules, and the specific communication rules are not limited herein.

[0074] The present invention also provides a wireless sensing method, which is based on the aforementioned wireless sensing system, and the main steps are as follows: S1, the transceiver sends a first radio frequency signal having a first frequency; S2, the wireless sensor device receives a first radio frequency signal having a first frequency, and returns a modulated frequency-converted signal to the transceiver device; S3, the transceiver receives and analyzes the modulated frequency conversion signal to obtain identity coding data, nominal sensing data and compensation data; wherein the target sensing data is obtained according to the nominal sensing data and the compensation data.

[0075] In step S1 , the first radio frequency signal sent by the transceiver 200 is used to provide radio frequency energy to the wireless sensor device within a specific communication range to wake up the wireless sensor device 100 to work.

[0076] In step S2, the wireless sensor device 100 receives the first radio frequency signal and returns a modulated frequency conversion signal under a preset communication rule.

[0077] In step S3, the transceiver 200 receives the modulated variable frequency signal, and obtains identity code data, nominal sensing data and background noise data by analyzing the variable frequency signal, and then obtains target sensing data according to the nominal sensing data and the background noise data.

[0078] Although the present invention is described herein with reference to the illustrative embodiments of the present invention, it should be understood that those skilled in the art can design many other modifications and implementations, which will fall within the scope and spirit of the principles disclosed in the present application. More specifically, within the scope disclosed in the present application, multiple variations and improvements can be made to the components and / or layout of the subject combination layout. In addition to the variations and improvements made to the components and / or layout, other uses will also be apparent to those skilled in the art.

Claims

1. A variable frequency sensing circuit, characterized in that: Including frequency conversion module and sensor modulation module; The frequency conversion module is used to convert a first radio frequency signal having a first frequency into a frequency conversion signal having a frequency different from the first frequency; The sensing modulation module is electrically connected to the frequency conversion module, and the sensing modulation module can be switched between a non-sensing state and a sensing state. When the sensing modulation module is in the non-sensing state, the frequency conversion module outputs a first frequency conversion signal containing background noise data; When the sensing modulation module is in the sensing state, the frequency conversion module outputs a second frequency conversion signal including background noise data and target sensing data.

2. A frequency conversion sensing circuit as claimed in claim 1, characterized in that: The sensing modulation module includes a modulation element, a first resonance unit and a second resonance unit; The modulation element comprises at least three ports, a first modulation port, a second modulation port and a third modulation port, the first modulation port receiving a first radio frequency signal; the first resonance unit is electrically connected to the second modulation port; The first end of the second resonance unit is electrically connected to the third modulation port.

3. A frequency conversion sensing circuit as claimed in claim 2, characterized in that: The sensing modulation module comprises a first switch element and a sensing unit, wherein a first end of the first switch element is electrically connected to the sensing unit, and a second end thereof is grounded; The second end of the first resonance unit or the second end of the second resonance unit is electrically connected to the first end of the first switch element and the sensing unit.

4. A frequency conversion sensing circuit as claimed in claim 2 or 3, characterized in that: The first resonance unit is one of a passive piezoelectric resonator, a parallel LC resonance circuit or a series LC resonance circuit; the second resonance unit is one of a passive piezoelectric resonator, a parallel LC resonance circuit, a series LC resonance circuit, an RF open line or an RF short line.

5. A frequency conversion sensing circuit as claimed in claim 4, characterized in that: The passive piezoelectric resonator includes at least one of a crystal resonator, a ceramic resonator, a surface acoustic wave piezoelectric resonator or a MEMS piezoelectric resonator.

6. A frequency conversion sensing circuit as claimed in claim 2 or 3, characterized in that: The modulation element includes a transistor having a heterojunction.

7. A frequency conversion sensing circuit as claimed in claim 2 or 3, characterized in that: The modulation element includes a heterojunction bipolar transistor or a field effect transistor.

8. A frequency conversion sensing circuit as claimed in claim 7, characterized in that: The field effect transistor includes one of a metal oxide semiconductor field effect transistor, a two-dimensional electron gas transistor or a high electron mobility transistor.

9. A frequency conversion sensing circuit as claimed in claim 3, characterized in that: The first switch element includes one of a diode, a metal oxide semiconductor field effect transistor, a bipolar junction transistor or an insulated gate bipolar transistor.

10. A wireless sensing circuit, characterized in that: It comprises an antenna module, a control module, and a frequency conversion sensing circuit as claimed in any one of claims 1 to 9; The frequency conversion sensing circuit is electrically connected to the control module and the antenna module respectively; The antenna module is configured to receive a first radio frequency signal having a first frequency in free space, and send a frequency-converting signal having a frequency different from the first frequency into the free space; The control module is configured to generate a working instruction for controlling the variable frequency sensing circuit based on the identity code data; The frequency conversion sensing circuit responds to the working instruction and outputs a first frequency conversion signal or a second frequency conversion signal.

11. A wireless sensing circuit as claimed in claim 10, characterized in that: The control module includes one of the following solutions: Energy conversion circuit and control circuit; or includes energy conversion circuit, energy management circuit and control circuit; or includes energy conversion circuit, demodulation circuit and control circuit; or includes energy conversion circuit, energy management circuit, demodulation circuit and control circuit; or includes energy conversion circuit, demodulation circuit, storage circuit and control circuit; or includes energy conversion circuit, demodulation circuit, storage circuit and control circuit.

12. A wireless sensing device, characterized in that: It comprises a packaging shell and the wireless sensing circuit as claimed in claim 10 or 11, wherein the wireless sensing circuit is fully or partially arranged in the packaging shell.

13. A wireless sensing system, characterized in that: comprising a transceiver and a plurality of wireless sensing devices as claimed in claim 12; The transceiver is used to send a first frequency radio frequency signal to the wireless sensor device, and receive a frequency conversion signal having a frequency different from the first frequency returned by the wireless sensor device that meets the preset communication rules; The frequency conversion signal may carry identity coding data, nominal sensing data and background noise data.

14. A wireless sensing method, using the wireless sensing system according to claim 13, characterized in that: The following steps are involved: S1, the transceiver sends a first radio frequency signal having a first frequency; S2, the wireless sensor device receives a first radio frequency signal having a first frequency, and returns a modulated frequency-converted signal to the transceiver device; S3, the transceiver receives and analyzes the modulated frequency conversion signal to obtain identity coding data, nominal sensing data and background noise data; wherein the target sensing data is obtained according to the nominal sensing data and the background noise data.

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