Frequency conversion sensing circuit, wireless sensing circuit, terminal and system

Abstract

The utility model discloses a frequency conversion sensing circuit, a wireless sensing circuit, a terminal and a system. Compensation data are obtained by utilizing frequency change of the frequency conversion signal of the frequency conversion unit in the background noise state. On one hand, a frequency conversion signal of the frequency conversion unit can be modulated through coded data, digital signal frequency conversion transmission is achieved, and the anti-interference capacity of the frequency conversion sensing circuit can be 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] This utility model relates to the field of wireless communication, and more specifically, to frequency conversion sensing circuits, wireless sensing circuits, terminals, and systems. Background Technology

[0002] Existing passive wireless frequency conversion sensors typically employ frequency division addressing (FDI) technology. When multiple wireless sensor terminals are within the communication range of the transceiver, there is a limitation on the number of terminals that can be accommodated within the communication bandwidth. Furthermore, when a wireless sensor terminal is operating, the returned sensing data includes both the target sensing quantity and external environmental interference components. In harsh environments, the accuracy of the wireless sensor terminal is severely challenged. Current technologies often add additional reference elements to obtain compensation data for external environmental influences. However, since the reference element is not part of the wireless sensor terminal's circuitry, its compensation effect is limited, and it increases the complexity and cost of the wireless sensor terminal. Therefore, improving the capacity and accuracy of wireless sensor terminals within the communication coverage area of ​​the transceiver is a problem that passive IoT technology needs to solve. Utility Model Content

[0003] This invention overcomes the shortcomings of the prior art by providing a frequency conversion sensing circuit, a wireless sensing circuit, a terminal, and a system, in order to solve at least one technical problem existing in the prior art.

[0004] One aspect of this utility model is to provide a frequency conversion sensing circuit.

[0005] A frequency conversion sensing circuit includes a frequency conversion unit and a sensing modulation unit electrically connected to each other.

[0006] The frequency conversion unit is configured to receive a first radio frequency signal having a first frequency, convert the first radio frequency signal into a frequency conversion signal having a frequency different from the first frequency, and output the frequency conversion signal.

[0007] The sensing modulation unit can be switched between a non-sensing state and a sensing state.

[0008] The frequency conversion unit includes a mixer subunit and a resonant subunit. The mixer subunit includes at least two ports. Its first port is used to input a first radio frequency signal, and the transmission path of the radio frequency signal is denoted as the first transmission path. Its second port is electrically connected to the first end of the resonant subunit, and the transmission path of the radio frequency signal is denoted as the second transmission path.

[0009] The frequency conversion sensing circuit is configured to output a frequency conversion signal containing nominal sensing data in the sensing state and to output a frequency conversion signal containing compensation data in the non-sensing state.

[0010] This application utilizes the frequency change of the inverter signal when the inverter unit is in a background noise state (at this time, the frequency change of the inverter signal of the inverter unit is only affected by changes in the external environment, such as from f m11 Change to f m12 The change in the data represents the background noise caused by changes in the external environment. Compensation data is obtained by using this compensation data as the background noise data caused by changes in the external environment. The target sensing data can be obtained by using the difference between the aforementioned nominal sensing data and the compensation data or background noise data.

[0011] The first switching element operates in response to a work instruction based on the identity code data. Upon receiving the first work instruction, it performs the first operation and enters a sensing state. At this time, the sensing unit can operate. The sensing unit, together with the external environment, affects the frequency of the frequency conversion signal output by the frequency conversion unit. The frequency of the frequency conversion signal simultaneously includes the target sensing data and the background noise data.

[0012] Upon receiving the second working instruction, the second operation is executed and the unit is in a non-sensing state. At this time, the sensing unit cannot work, and the frequency of the frequency conversion signal output by the frequency conversion unit is only affected by the external environment. The frequency conversion signal data only contains background noise data.

[0013] The advantages of this invention are as follows: on the one hand, the encoded data can modulate the frequency conversion signal of the frequency conversion unit, realizing the frequency conversion transmission of digital signals and improving the anti-interference capability of the frequency conversion sensing circuit; on the other hand, the periodic switching of the return frequency conversion signal realizes the transmission of identity encoded data, and the change of carrier frequency represents the nominal sensing data and background noise data. By collecting the frequency change of the frequency conversion signal under two working states within a certain period of time, accurate target sensing data can be obtained.

[0014] A further technical solution is that the mixing subunit includes one of the following:

[0015] Option 1:

[0016] The mixing subunit includes a first inductor and a first varactor diode connected in series, wherein the first end of the first inductor is electrically connected to the first port of the mixing subunit, the second end of the first inductor is electrically connected to the first end of the first varactor diode, and the second end of the first varactor diode is electrically connected to the second port of the mixing subunit.

[0017] Option 2:

[0018] The mixing subunit includes a first inductor, a first varactor diode, and a second varactor diode connected in series. The first end of the first inductor is electrically connected to the first port of the mixing subunit, the second end of the first inductor is electrically connected to the first end of the first varactor diode, the second end of the first varactor diode is electrically connected to the second end of the second varactor diode, and the first end of the second varactor diode is connected to the second port of the mixing subunit.

[0019] The mixer subunit and the resonator subunit work together to generate a frequency conversion frequency f based on a first radio frequency signal with a first frequency (f1). m (f m =f1±n·f r , where f r The frequency conversion signal is the resonant frequency of the resonant oscillator unit (where n is a natural number). The above process utilizes the parametric mixing process of the varactor diode. For details, please refer to the prior patent application CN202411147061.0, which will not be elaborated here.

[0020] A further technical solution is that the sensing modulation unit is disposed in one of the following positions: on the bypass of the first transmission path; or on the bypass of the second transmission path; or electrically connected to the second end of the resonator unit.

[0021] A further technical solution is that the sensing modulation unit includes a first switching element and a sensing subunit, and the first switching element and the sensing subunit are configured in one of the following ways:

[0022] Method 1:

[0023] The first terminal of the first switching element is electrically connected to the frequency conversion unit, and the second terminal of the first switching element is grounded; the sensing subunit is electrically connected to the first terminal of the first switching element.

[0024] Method 2:

[0025] Alternatively, the first end of the first switching element is electrically connected to the frequency conversion unit, and the second end of the first switching element is electrically connected to the sensing subunit.

[0026] A further technical solution is that the sensing modulation unit includes a first switching element and a sensing subunit;

[0027] The first terminal of the first switching element is electrically connected to the frequency converter unit, and the second terminal of the first switching element is grounded.

[0028] The sensing subunit is electrically connected to the first end of the first switching element.

[0029] A further technical solution is that when the first switching element and the sensing subunit are configured in the manner described in the first method, the resonant subunit is one of a passive piezoelectric resonator or a series LC resonant circuit.

[0030] When the first switching element and the sensing subunit are configured in the manner described in Method 2, the resonant subunit is a parallel LC resonant circuit.

[0031] A further technical solution is that the first switching element includes one of a diode, a metal-oxide-semiconductor field-effect transistor, a bipolar junction transistor, or an insulated gate bipolar transistor.

[0032] This utility model also provides a wireless sensing circuit, including an antenna unit, a control unit, and the frequency conversion sensing circuit described above.

[0033] The antenna unit is configured to receive a first radio frequency signal with a first frequency in free space, and to transmit a frequency-converted signal with a frequency different from the first frequency into free space.

[0034] The control unit is configured to generate operating instructions for controlling the frequency converter sensing circuit based on the identity code data;

[0035] The frequency conversion sensing circuit responds to the aforementioned operating command and modulates the frequency conversion signal.

[0036] A further technical solution is that the control unit includes an energy conversion circuit and a control circuit; or includes an energy conversion circuit, an energy management circuit, and a control circuit; or includes an energy conversion circuit, a demodulation circuit, and a control circuit; or includes an energy conversion circuit, an energy management circuit, a demodulation circuit, and a control circuit; or includes an energy conversion circuit, a demodulation circuit, a storage circuit, and a control circuit; or includes an energy conversion circuit, an energy management circuit, a demodulation circuit, a storage circuit, and a control circuit.

[0037] This utility model also provides a wireless sensing terminal, characterized in that it includes a housing and a wireless sensing circuit as described above, wherein all or part of the wireless sensing circuit is disposed in the housing.

[0038] This utility model also provides a wireless sensing system, characterized in that it includes a plurality of wireless sensing terminals and transceivers as described above.

[0039] The transceiver is used to send a first radio frequency signal with a first frequency to the wireless sensing terminal, and to receive a frequency-converted signal with a frequency different from the first frequency returned by the wireless sensing terminal that meets preset communication rules.

[0040] Compared with the prior art, the present invention has at least the following beneficial effects: In this solution, nominal sensing data and background noise data as compensation data are extracted separately in two states of identity coding data in the same frequency conversion sensing circuit. Without introducing other unnecessary components, the background noise influence of the environment in which the frequency conversion 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 terminal.

[0041] In this scheme, the frequency conversion unit is a working component involved in both working states of the frequency conversion sensing circuit (i.e., sensing state and non-sensing state). This scheme cleverly utilizes the modulation characteristics of identity code data to extract the degree of influence of the frequency conversion unit on the external environment. Compared with the existing technology that uses auxiliary reference elements as compensation data for the influence of the external environment, it has many advantages such as high fidelity of target sensing data, good compensation effect, simple structure, and low cost.

[0042] In this scheme, the digitally encoded identity signal and sensor data are modulated onto the frequency conversion signal of the frequency conversion unit, realizing passive wireless digital signal frequency conversion transmission. This can greatly increase the number of wireless sensor terminals that can be mounted within the communication range of the transceiver device, and overcome the problems of limited number of wireless sensor terminals and complex debugging in the same transceiver device under the existing transceiver frequency communication system.

[0043] In this scheme, by transmitting the frequency conversion sensor signal back in a digital encoding manner, many defects of analog frequency conversion sensor signals, such as weak anti-interference ability, low accuracy, low precision, and poor robustness in wireless transmission, can be overcome. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the frequency conversion sensing circuit of this utility model;

[0045] Figure 2 This is a schematic diagram of the output signal of the frequency converter sensing circuit.

[0046] Figure 3 This is a schematic diagram of a frequency converter unit structure according to one embodiment;

[0047] Figure 4 This is a schematic diagram of the structure of a frequency conversion sensing circuit according to one embodiment;

[0048] Figure 5 This is a schematic diagram of the structure of a frequency conversion sensing circuit according to yet another embodiment;

[0049] Figure 6 This is a schematic diagram of the structure of a frequency conversion sensing circuit according to yet another embodiment;

[0050] Figure 7 A schematic diagram of the structure of a frequency conversion sensing circuit according to another embodiment;

[0051] Figure 8 This is a schematic diagram of a wireless sensing circuit according to one embodiment;

[0052] Figure 9 This is a schematic diagram of a wireless sensing system according to one embodiment.

[0053] In the diagram, 10 is the frequency conversion sensing circuit, 11 is the antenna unit, 12 is the control unit, 13 is the frequency conversion unit, 131 is the mixer subunit, 1311 is the first inductor, 1312 is the first varactor diode, 1313 is the second varactor diode, 132 is the resonator unit, 1321 is the passive piezoelectric resonator, 1322 is the first parallel inductor, 1323 is the first parallel capacitor, 1324 is the first series inductor, 1325 is the first series capacitor, 14 is the sensing modulation unit, 141 is the first switching element, 142 is the sensing subunit, 100 is the wireless sensing circuit, and 200 is the transceiver. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0055] Figure 1 A frequency conversion sensing circuit 10 is provided, including a frequency conversion unit 13 and a sensing modulation unit 14, wherein the frequency conversion unit 13 is used to convert a first radio frequency signal having a first frequency (f1) into a signal having a frequency (f2). m Unlike the second frequency conversion signal of the first frequency, the sensing modulation unit 14 is controlled by the identity code data and is divided into sensing state and non-sensing state, thereby loading the identity code data and sensing data onto the frequency conversion signal; the frequency conversion sensing circuit 10 extracts nominal sensing data according to the frequency change of the frequency conversion signal in the sensing state, and extracts compensation data according to the frequency change of the frequency conversion signal in the non-sensing state.

[0056] For example, Figure 2 A schematic diagram of the output of the first modulation port of a frequency conversion sensing circuit according to an embodiment is shown. The horizontal axis represents time, and the vertical axis represents the operating state of the sensing modulation unit 14. In one example, the sensing modulation unit 14 includes two operating states: sensing state V1 and non-sensing state V2.

[0057] Within a data transmission cycle, identity code data can be extracted based on the combination of sensing state V1 and non-sensing state V2 of sensing modulation unit 14. Nominal sensing data is obtained based on the frequency change of the frequency conversion signal of frequency conversion unit 13 under sensing state. For example, when the frequency conversion signal changes from f due to changes in the target sensing quantity and the external environment... m21 Change to fm22 Nominal sensing data can be obtained based on the pre-mapping relationship between frequency and sensing quantity. It should be understood that this nominal sensing data includes both the target sensing data and the background noise data caused by changes in the external environment. The harsher the environment in which the frequency converter sensing circuit is located, the lower the accuracy of the aforementioned nominal sensing data. Therefore, this application utilizes the frequency change of the frequency converter signal in the non-sensing state of the frequency converter unit 13 (corresponding to the non-sensing state of the sensing modulation unit 14). (At this time, the frequency change of the frequency converter signal of the frequency converter unit 13 is only affected by changes in the external environment, for example, from f...) m11 Change to f m12 The change in the data represents the background noise caused by changes in the external environment. Compensation data is obtained by using this compensation data as the background noise caused by changes in the external environment. The target sensing data can be obtained by using the difference between the aforementioned nominal sensing data and the compensation data.

[0058] This configuration has two advantages. First, it allows the digitally encoded identity data to modulate the frequency conversion signal of the frequency conversion unit 13, achieving digital signal frequency conversion transmission and improving the anti-interference capability of the frequency conversion sensing circuit. Second, the periodic switching of the return frequency conversion signal enables the transmission of the identity data. At the same time, the change in carrier frequency represents the nominal sensing data and background noise data. By collecting the frequency changes of the frequency conversion signal under two working states within a certain period of time, the sensing quantity of the target under test can be obtained. In other words, it achieves simultaneous loading of amplitude modulation and frequency modulation. Amplitude modulation enables the transmission of digitally encoded identity data, while frequency modulation enables the transmission of nominal sensing data and background noise data. Compared with frequency division addressing analog sensing, it has higher sensing accuracy and precision.

[0059] It should be noted that there are multiple ways to implement the ultra-low power frequency converter unit 13. For example, such as Figure 3 As shown, the frequency conversion unit 13 includes a mixing subunit 131 and a resonant subunit 132. The mixing subunit 131 includes at least two ports, namely a first port and a second port. The first port of the mixing subunit 131 is used to input a first radio frequency signal with a first frequency (f1), and the transmission path of the radio frequency signal is denoted as the first transmission path. The second port of the mixing subunit 131 is electrically connected to the resonant subunit 132, and the transmission path of the radio frequency signal is denoted as the second transmission path.

[0060] Figure 4 A frequency conversion sensing circuit 10 is provided, including a frequency conversion unit 13 and a sensing modulation module 14; the frequency conversion unit 13 includes a mixing subunit 131 and a resonant subunit 132; the mixing subunit 131 includes a first inductor 1311 and a first varactor diode 1312 connected in series, and the resonant subunit 132 includes a passive piezoelectric resonator 1321.

[0061] The first terminal of the first inductor 1321 serves as the radio frequency signal input / output port. The second terminal of the first inductor 1321 is electrically connected to the first terminal of the first varactor diode 1312, and the second terminal of the first varactor diode 1312 is electrically connected to the first terminal of the passive piezoelectric resonator 1321. The sensing modulation unit 14 includes a first switching element 141 and a sensing subunit 142. The first terminal of the first switching element 141 is electrically connected to the second terminal of the passive piezoelectric resonator 1321, and its second terminal is grounded. The sensing subunit 142 is electrically connected to the first terminal of the first switching element 141. In this embodiment, the mixing subunit 131 and the resonator subunit 132 cooperate to generate a frequency conversion frequency f based on the first radio frequency signal having a first frequency (f1). m (f m =f1±n·f r , where f r The frequency of the resonant frequency of the resonant element 132 (where n is a natural number) is the frequency-converted signal.

[0062] It should be understood that, Figure 4 In one embodiment, as an alternative, the first resonant unit 132 can also be a series LC resonant circuit.

[0063] Figure 5 Another frequency conversion sensing circuit 10 is provided, comprising a frequency conversion unit 13 and a sensing modulation unit 14. The sensing modulation unit 14 includes a first switching element 141 and a sensing unit 142 connected in series; the resonator unit 132 adopts a parallel LC resonant circuit, including a first parallel capacitor 1323 and a first parallel inductor 1322. The first terminal of the first parallel inductor 1322 is electrically connected to the second terminal of the first varactor diode 1312, and its second terminal is grounded. The first terminal of the first parallel capacitor 1323 is electrically connected to the first terminal of the first parallel inductor 1322, and its second terminal is grounded; the first terminal of the first switching element 141 is electrically connected to the first terminal of the first parallel inductor 1322, and its second terminal is electrically connected to the sensing subunit 142.

[0064] exist Figure 5 In the embodiment shown, the sensing modulation unit is electrically connected to the second port of the resonator unit. It should be understood that the sensing modulation unit can also be disposed on the bypass of the first transmission path or the bypass of the second transmission path.

[0065] Figure 6 Another frequency conversion sensing circuit 10 is provided, in Figure 4Based on the illustrated embodiment, the mixing subunit 131 further includes a second varactor diode 1313, which is reverse-connected to the first varactor diode 1312, i.e., the second terminal of the second varactor diode 1313 is electrically connected to the second terminal of the first varactor diode 1312, and the first terminal of the second varactor diode 1313 is electrically connected to the resonant subunit 132. The resonant subunit 132 adopts a passive piezoelectric resonator 1321, and the first terminal of the passive piezoelectric resonator 1321 is electrically connected to the first terminal of the second varactor diode 1313. The sensing modulation unit 14 includes a first switching element 141 and a sensing subunit 142, the first terminal of the first switching element 141 is electrically connected to the second terminal of the passive piezoelectric resonator 1321, and its second terminal is grounded, and the sensing subunit 142 is electrically connected to the first terminal of the first switching element 141.

[0066] Figure 7 Another frequency conversion sensing circuit 10 is provided, in Figure 6 Based on the embodiment shown, the resonator unit 132 replaces the passive piezoelectric resonator 1321 with a series LC resonant circuit. The series LC resonant circuit includes a first series capacitor 1325 and a first series inductor 1324. The first end of the first series capacitor 1325 is electrically connected to the first end of the second varactor diode 1313, and its second end is electrically connected to the first end of the first series inductor 1324. The second end of the first series inductor 1324 is electrically connected to the sensing modulation unit 14.

[0067] It should be noted that, in Figure 6 In the illustrated embodiment, the resonator unit 132 is a passive piezoelectric resonator 1321; in Figure 7 In the illustrated embodiment, the resonator unit 132 is a series LC resonant circuit. The resonator unit 132 can be a passive piezoelectric resonator 1321, a series LC resonant circuit, or a parallel LC resonant circuit.

[0068] However, when the resonator unit 132 adopts such as Figure 5 When using a parallel LC resonant circuit, the sensing modulation unit 14 also needs to adopt a corresponding design such as... Figure 5 The first switching element 141 and sensing subunit 142 are shown in series. In this case, the first switching element 141 and sensing subunit 142 in series can be alternatively arranged in the bypass of the first transmission path or the second transmission path.

[0069] In any of the foregoing embodiments, the first switching element 141 operates in response to a working instruction based on identity code data. Upon receiving a first working instruction, it performs a first operation and is in a sensing state; upon receiving a second working instruction, it performs a second operation and is in a non-sensing state. In this embodiment, the first working instruction is an open instruction, meaning that the first switching element 141 is in an open state after responding to the first working instruction, and the sensing state corresponds to the first switching element 141 being in an open state; the second working instruction is a close instruction, meaning that the first switching element 141 is in a closed state after responding to the second working instruction, and the non-sensing state corresponds to the first switching element 141 being in a closed state. When the first switching element 141 is closed, the frequency converter 13 is in a non-sensing state. Specifically, the sensing unit 142 cannot operate, and the frequency of the frequency converter signal output by the frequency converter 13 is only affected by the external environment. At this time, the frequency converter signal data only contains background noise data. When the first switching element 141 is open, the frequency converter 13 is in a sensing state. Specifically, the sensing unit 142 can operate, and the sensing unit 142, together with the external environment, affects the frequency of the frequency converter signal output by the frequency converter 13. At this time, the frequency converter signal frequency simultaneously contains both target sensing data and background noise data. By acquiring the frequency converter signal data under the two operating states of the frequency converter sensing circuit, nominal sensing data and background noise data can be obtained respectively.

[0070] In any of the foregoing embodiments, the first switching element 141 may be any element capable of enabling the passage and blocking of radio frequency signals on the signal transmission path, including but not limited to diodes, metal-oxide-semiconductor field-effect transistors (MOSFETs), bipolar junction transistors (BJTs), or insulated gate bipolar transistors (IGBTs).

[0071] In any of the foregoing embodiments, the passive piezoelectric resonator includes, but is not limited to, crystal resonators, ceramic resonators, surface acoustic wave piezoelectric resonators, or MEMS piezoelectric resonators.

[0072] In any of the foregoing embodiments, the frequency conversion unit 13 can be constructed with a single input / output port (i.e., the first radio frequency signal and the frequency conversion signal share the same port) or with a different input / output port (e.g., the first radio frequency signal is input from the first port of the mixer subunit, and the frequency conversion signal is output from another port electrically connected to the first port, or from another port electrically connected to the second port).

[0073] It should be noted that the inductor elements appearing in the foregoing embodiments can be either a single real inductor element or an equivalent inductor element, such as an equivalent inductor element obtained by connecting two independent real inductor elements in series, or an equivalent inductor element obtained by other circuit configurations. Similarly, the capacitor elements appearing in the foregoing embodiments can be either a single real capacitor element or an equivalent capacitor element, such as an equivalent capacitor element obtained by connecting two independent real capacitor elements in parallel, or an equivalent capacitor element obtained by other circuit configurations. Unless otherwise specified, the terms "inductor element" and "capacitor element" as used below have the same meaning and will not be elaborated further.

[0074] This utility model also provides a wireless sensing circuit 100, such as Figure 8 As shown, it includes an antenna unit 11, a control unit 12, and a frequency conversion sensing circuit 10 as described in any of the preceding embodiments. The frequency conversion sensing circuit 10 is electrically connected to the control unit 12 and the antenna unit 11, respectively.

[0075] Antenna unit 11 is configured to receive a first radio frequency signal with a first frequency (f1) in free space, and to transmit a frequency-converted signal with a frequency different from the first frequency into free space.

[0076] The control unit 12 is configured to generate operating instructions for the control frequency conversion sensing circuit 10 based on the identity code data.

[0077] The frequency conversion sensing circuit 10 responds to the aforementioned working command and modulates the frequency conversion signal.

[0078] Specifically, the frequency conversion sensing circuit 10 executes corresponding operations according to the operating instructions issued by the control unit 12. For example, upon receiving a first operating instruction, it performs a first operation and enters a sensing state; upon receiving a second operating instruction, it performs a second operation and enters a non-sensing state. Specifically, when the frequency conversion sensing circuit 10 is in a sensing state, it sends a frequency conversion signal corresponding to the nominal sensing data to the antenna unit 11; when the frequency conversion sensing circuit 10 is in a non-sensing state, it sends a frequency conversion signal corresponding to the background noise data to the antenna unit 11.

[0079] The control unit 12 can be any passive or low-power control device or apparatus capable of generating digitally encoded signals, including but not limited to control devices or apparatuses operating based on ambient energy; wherein ambient energy includes, but is not limited to, radio frequency energy, light energy, thermal energy, temperature difference energy, and vibration energy in free space. It is understood that the specific form of the control unit 12 is diverse and can be configured according to the application scenario requirements. For example, it may include an energy conversion circuit and a control circuit; or it may include an energy conversion circuit, an energy management circuit, and a control circuit; or it may include an energy conversion circuit, a demodulation circuit, and a control circuit; or it may include an energy conversion circuit, an energy management circuit, a demodulation circuit, and a control circuit; or it may include an energy conversion circuit, an energy management circuit, a demodulation circuit, a storage circuit, and a control circuit; or it may include an energy conversion circuit, an energy management circuit, a demodulation circuit, a storage circuit, and a control circuit.

[0080] During operation, the remote transceiver sends a radio frequency signal with a first frequency, i.e., a first radio frequency signal. The antenna unit 11 receives the first radio frequency signal in free space and transmits it to the frequency conversion sensing circuit 10. The frequency conversion sensing circuit 10 operates under the control of the control unit 12. When the frequency conversion sensing circuit 10 is in sensing mode, it sends a frequency conversion signal corresponding to the nominal sensing data to the antenna unit 11. When the frequency conversion sensing circuit 10 is in non-sensing mode, it sends a frequency conversion signal corresponding to the background noise data to the antenna unit 11. The frequency conversion signal is coupled out into free space through the antenna unit 11. The remote transceiver receives the modulated frequency conversion signal and analyzes it to obtain the identity code data, nominal sensing data, and compensation data of the corresponding wireless sensing circuit.

[0081] In principle, the first radio frequency signal can be any suitable first frequency radio frequency signal. The first frequency can be an unlicensed frequency band open to industrial, scientific and medical institutions, or a licensed wireless communication frequency band, such as the 5G NR communication band. For example, the first frequency includes, but is not limited to, 125KHz, 13.56MHz, 433MHz, 800MHz, 900MHz, 950MHz, 2.4GHz or 5.8GHz, and is not specifically limited to any particular frequency.

[0082] Antenna element 11 can be any antenna object capable of enabling high-efficiency transmission and reception of different frequencies.

[0083] In some embodiments, the control unit 12 includes a conventional RFID chip that receives radio frequency signals (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 demodulation circuits, storage circuits, and a microcontroller, operate under direct current conditions. The chip is configured to internally store identification code data and operate according to a pre-agreed communication strategy. The aforementioned pre-agreed communication rules can be common RFID communication rules, such as the anti-collision method described in prior patent application CN200910095463.X; specific communication rules are not limited.

[0084] It should be understood that the energy conversion circuit varies depending on the ambient energy utilized. When the ambient energy is radio frequency (RF) energy, the energy conversion circuit can be any suitable circuit that converts RF signals into direct current (DC), including but not limited to diode rectifier circuits; when the ambient energy is light energy, the energy conversion circuit can be any suitable circuit that converts light energy into DC, including but not limited to solar panels or photovoltaic panels.

[0085] This utility model also provides a wireless sensing terminal, which includes a housing and the wireless sensing circuit disclosed in any of the foregoing embodiments. All or part of the wireless sensing circuit is disposed within the housing, which protects the wireless sensing circuit to improve its mechanical performance, environmental performance, and service life.

[0086] In some embodiments, the wireless sensing circuitry is entirely disposed on the package housing, and the package housing is made of a wave-transparent material at least at the position corresponding to the antenna element 11.

[0087] In some implementations, the antenna unit 11 of the wireless sensing circuit is located outside the package housing, while other modules are located inside the package housing. The package housing is provided with a communication interface that is electrically connected to the antenna unit 11.

[0088] This solution also provides a wireless sensing system, such as Figure 9 As shown, it includes a transceiver 200 and several wireless sensing terminals 300 disclosed in any of the foregoing embodiments.

[0089] The transceiver 200 is used to send a first radio frequency signal with a first frequency (f1) to the wireless sensing terminal 300, and to receive a frequency-converted signal with a frequency different from the first frequency returned by the wireless sensing terminal 300 that meets preset communication rules.

[0090] The frequency conversion signal can carry identity code data, nominal sensing data, and compensation data.

[0091] Those skilled in the art should understand that the aforementioned preset communication rules can be common RFID communication rules, and no specific communication rules are limited here.

[0092] The main steps of the wireless sensing system method are as follows:

[0093] S1, the transceiver 200 transmits a first radio frequency signal having a first frequency;

[0094] S2, the wireless sensing terminal 300 receives a first radio frequency signal with a first frequency and returns a modulated frequency-converted signal to the transceiver 200 based on the identity code data.

[0095] S3, the transceiver 200 receives and analyzes the frequency conversion signal to obtain identity code data, nominal sensing data and compensation data.

[0096] In step S1, the first radio frequency signal sent by the transceiver 200 is used to provide radio frequency energy to the wireless sensing terminal within a specific communication range, thereby waking up the wireless sensing terminal 300 to work.

[0097] In step S2, the wireless sensing terminal 300 receives the first radio frequency signal and returns a modulated frequency conversion signal under the preset communication rules.

[0098] In step S3, the transceiver 200 receives the modulated frequency conversion signal. By analyzing the frequency conversion signal, it can obtain the identity code data, nominal sensing data, and compensation data, and then obtain the target sensing data based on the nominal sensing data and compensation data.

[0099] Although the present invention has been described herein with reference to illustrative embodiments, it should be understood that many other modifications and implementations can be devised by those skilled in the art, which will fall within the scope and spirit of the principles disclosed herein. More specifically, various variations and improvements can be made to the components and / or layout of the subject matter combination within the scope of the present application. Besides variations and improvements to the components and / or layout, other uses will be apparent to those skilled in the art.

Claims

1. A variable frequency sensing circuit, comprising: The variable frequency unit and the sensing modulation unit are electrically connected. The variable frequency unit is configured to receive a first radio frequency signal with a first frequency, convert the first radio frequency signal into a variable frequency signal with a frequency different from the first frequency, and output the variable frequency signal. The sensing modulation unit can be switched to a non-sensing state and a sensing state. The variable frequency unit includes a mixing sub-unit and a resonant sub-unit, wherein the mixing sub-unit includes at least two ports, a first port of which is used to input a first radio frequency signal, and the radio frequency signal transmission path is recorded as a first transmission path; a second port of which is electrically connected to a first end of the resonant sub-unit, and the radio frequency signal transmission path is recorded as a second transmission path. The variable frequency sensing circuit is configured to output a variable frequency signal containing nominal sensing data in the sensing state, and output a variable frequency signal containing compensation data in the non-sensing state.

2. A variable frequency sensing circuit as claimed in claim 1, characterized in that The mixing sub-unit includes one of the following schemes: Scheme one: The mixing sub-unit includes a first inductive element and a first varactor diode connected in series, wherein the first end of the first inductive element is electrically connected to the first port of the mixing sub-unit, the second end of the first inductive element is electrically connected to the first end of the first varactor diode, and the second end of the first varactor diode is electrically connected to the second port of the mixing sub-unit. Scheme two: The mixing sub-unit includes a first inductive element, a first varactor diode and a second varactor diode connected in series, wherein the first end of the first inductive element is electrically connected to the first port of the mixing sub-unit, the second end of the first inductive element is electrically connected to the first end of the first varactor diode, the second end of the first varactor diode is electrically connected to the second end of the second varactor diode, and the first end of the second varactor diode is electrically connected to the second port of the mixing sub-unit.

3. A variable frequency sensing circuit as claimed in claim 1, characterized in that The sensing modulation unit is arranged at one of the following positions: arranged on the bypass of the first transmission path; or arranged on the bypass of the second transmission path; or electrically connected to the second end of the resonant sub-unit.

4. A frequency varying sensing circuit according to any one of claims 1 to 3, wherein The sensing modulation unit includes a first switching element and a sensing sub-unit, and the first switching element and the sensing sub-unit are connected in one of the following ways: Way one: The first end of the first switching element is electrically connected to the variable frequency unit, and the second end of the first switching element is grounded; the sensing sub-unit is electrically connected to the first end of the first switching element. Way two: Or, the first end of the first switching element is electrically connected to the variable frequency unit, and the second end of the first switching element is electrically connected to the sensing sub-unit.

5. The variable frequency sensing circuit of claim 4, wherein: When the first switching element and the sensing sub-unit are arranged in the way one, the resonant sub-unit is one of a passive piezoelectric resonator and a series LC resonant circuit; When the first switching element and the sensing sub-unit are arranged in the way two, the resonant sub-unit is a parallel LC resonant circuit.

6. A frequency varying sensing circuit according to any one of claims 1 to 3, wherein The first switching element includes one of a diode, a metal oxide semiconductor field effect transistor, a bipolar junction transistor and an insulated gate bipolar transistor.

7. A wireless sensing circuit, comprising: The variable frequency sensing circuit includes an antenna unit, a control unit and the variable frequency sensing circuit of any one of claims 1-6. The antenna unit is configured to receive a first radio frequency signal with a first frequency in free space, and to transmit a frequency conversion signal with a frequency different from the first frequency into the free space; The control unit is configured to generate a working instruction for controlling the frequency conversion sensing circuit based on the identity coding data; The frequency conversion sensing circuit modulates the frequency conversion signal in response to the aforementioned working instruction.

8. A wireless sensing circuit as claimed in claim 7, characterized in that The control unit comprises an energy conversion circuit and a control circuit; or comprises an energy conversion circuit, an energy management circuit and a control circuit; or comprises an energy conversion circuit, a demodulation circuit and a control circuit; or comprises an energy conversion circuit, an energy management circuit, a demodulation circuit and a control circuit; or comprises an energy conversion circuit, a demodulation circuit, a storage circuit and a control circuit; or comprises an energy conversion circuit, an energy management circuit, a demodulation circuit, a storage circuit and a control circuit.

9. A wireless sensing terminal, characterized by The wireless sensing circuit as claimed in claim 8 is wholly or partially arranged in the packaging shell.

10. A wireless sensing system, characterized by The transceiving device is configured to transmit a first radio frequency signal with a first frequency to the wireless sensing terminal, and to receive a frequency conversion signal with a frequency different from the first frequency returned by the wireless sensing terminal in response to a preset communication rule. ​

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