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

Abstract

The utility model discloses a frequency conversion sensing circuit, a wireless frequency conversion sensing circuit, a wireless sensing device and a system, which belong to the field of communication, and the frequency conversion sensing circuit comprises a frequency conversion unit, a modulation unit, an acquisition control unit and a sensing unit which are electrically connected in sequence, wherein the frequency conversion unit is used for converting a first radio frequency signal with a first frequency into a frequency conversion signal with a frequency different from the first frequency; the sensing unit is used for sensing target sensing data; the acquisition control unit is used for acquiring digital sensing data according to target sensing data and outputting a working instruction to the modulation unit; and the modulation unit is used for modulating the frequency conversion unit according to the working instruction so as to load modulation information to the frequency conversion signal. According to the scheme, the low-power-consumption digital sensing technology is combined with the ultra-low-power-consumption frequency conversion technology, and the wireless working distance and the wireless sensing precision are both considered.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of communication, concretely relates to frequency conversion sensing circuit, wireless frequency conversion sensing circuit, wireless sensing device and system. BACKGROUND

[0002] On the one hand, the existing passive wireless internet of things technology usually adopts frequency division addressing technology, when there are multiple wireless sensing terminals in the communication range of the transceiving device, there is the trouble that only a limited number of wireless sensing terminals can be accommodated in the communication bandwidth.

[0003] On the other hand, in some scenarios, the wireless sensing terminal cannot meet the use demand of the scene on sensing precision by using a passive sensor, and cannot meet the demand of the scene on wireless working distance by using an active sensor because of its high power consumption, therefore, how to improve the capacity of the wireless sensing terminal in the communication coverage range of the transceiving device and take into account the wireless working distance and wireless sensing precision is a problem to be solved in the passive wireless internet of things technology. UTILITY MODEL CONTENT

[0004] In view of the above-mentioned deficiencies in the prior art, the utility model provides a frequency conversion sensing circuit, wireless frequency conversion sensing circuit, wireless sensing device and system.

[0005] A frequency conversion sensing circuit, comprising a frequency conversion unit, a modulation unit, an acquisition control unit and a sensing unit connected in sequence, wherein:

[0006] The frequency conversion unit is used for converting a first radio frequency signal with a first frequency into a frequency conversion signal with a frequency different from the first frequency;

[0007] The sensing unit is used for sensing target sensing data;

[0008] The acquisition control unit is used for acquiring digital sensing data according to the target sensing data, and outputting a working instruction to the modulation unit;

[0009] The modulation unit is used for modulating the frequency conversion unit according to the working instruction, so as to load the modulation information onto the frequency conversion signal;

[0010] The frequency conversion unit comprises a mixing subunit and a resonance subunit, wherein the mixing subunit comprises at least two ports, wherein the first port is used for inputting the first radio frequency signal with the first frequency and outputting the frequency conversion signal with the frequency different from the first frequency, and the second port is electrically connected with the resonance subunit.

[0011] Further, the mixing subunit comprises one of the following schemes:

[0012] Scheme one:

[0013] The mixing subunit includes a first inductor and a first varactor diode connected in series. The first end of the first inductor serves as a radio frequency (RF) signal input port, and the RF signal transmission path is denoted as the first transmission path. The second end of the first inductor is electrically connected to the first end of the first varactor diode, and the RF signal transmission path is denoted as the second transmission path. The second end of the first varactor diode is electrically connected to the first end of the resonator unit, and the RF signal transmission path is denoted as the third transmission path.

[0014] Option 2:

[0015] 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 serves as the radio frequency (RF) signal input port, and this RF signal transmission path is denoted as the first transmission path. The second end of the first inductor is electrically connected to the first end of the first varactor diode, and this RF signal transmission path is denoted as the second transmission path. The second end of the second varactor diode is electrically connected to the second end of the first varactor diode, and this RF signal transmission path is denoted as the fourth transmission path. The first end of the second varactor diode is electrically connected to the resonator unit, and this RF signal transmission path is denoted as the fifth transmission path.

[0016] Furthermore, the modulation unit includes a first switching element;

[0017] In Scheme 1, the first switching element is located in one of the following positions:

[0018] It is set on the bypass of one of the first to third transmission paths; or, it is set inside the resonator unit; or, a matching circuit is set at one of the first to third transmission paths, and the first switching element is set inside the matching circuit.

[0019] In Scheme 2, the first switching element is located in one of the following positions:

[0020] A bypass is provided on one of the first, second, fourth, and fifth transmission paths; or, it is provided inside the resonator unit; or, a matching circuit is provided at one of the first, second, fourth, and fifth transmission paths, and the first switching element is provided inside the matching circuit.

[0021] Furthermore, in Scheme 1, the frequency converter signal is output through a bypass of one of the first to third transmission paths; in Scheme 2, the frequency converter signal is output through a bypass of one of the first, second, fourth, and fifth transmission paths.

[0022] Furthermore, the resonator unit includes a passive piezoelectric resonator, or an equivalent LC parallel resonant circuit, or an equivalent LC series resonant circuit.

[0023] Furthermore, the frequency conversion signal may carry sensor data, identity code data, or a combination of both.

[0024] A wireless frequency conversion sensing circuit includes an antenna unit and a frequency conversion sensing circuit, wherein the frequency conversion sensing circuit is electrically connected to the antenna unit, and wherein:

[0025] The antenna element 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.

[0026] The frequency conversion sensing circuit receives a first radio frequency signal transmitted from the antenna unit and transmits a frequency conversion signal modulated at a frequency different from the first frequency to the antenna unit.

[0027] A wireless sensing device includes a housing and a wireless frequency conversion sensing circuit, wherein all or part of the wireless frequency conversion sensing circuit is disposed in the housing.

[0028] Furthermore, all of the wireless frequency conversion sensing circuits are housed inside the encapsulation housing, and at least the positions corresponding to the antenna units on the encapsulation housing are made of wave-transparent material.

[0029] Furthermore, the antenna unit of the wireless frequency conversion sensing circuit is located outside the packaging housing, while the other units are located inside the packaging housing. The packaging housing is provided with a communication interface that is electrically connected to the antenna unit.

[0030] A wireless sensing system includes a transceiver and a plurality of wireless sensing devices, wherein the transceiver is used to send a first frequency radio frequency signal to the wireless sensing devices and to receive a frequency-converted signal from the wireless sensing devices that meets preset communication rules and has a frequency different from the first frequency.

[0031] This utility model has the following beneficial effects:

[0032] On the one hand, by adopting a different frequency communication system, the problems of short communication distance and severe co-frequency interference that exist in the same frequency communication system can be overcome. On the other hand, by loading identity information and sensor information into the different frequency return signal, the accurate identification and positioning of numerous wireless sensor terminals in the communication coverage area of ​​the transceiver device can be achieved, overcoming the problems of limited number of wireless sensor terminals and complex debugging of the same transceiver device under the different frequency communication system in the prior art.

[0033] In this invention, the digitally encoded identity signal and sensor information are modulated onto the frequency conversion signal of the frequency conversion module, 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, solving the problem of the extremely limited number of wireless sensor terminals that can be mounted in the current passive wireless frequency conversion technology that relies on frequency division.

[0034] In this invention, by digitizing the sensing information, the accuracy and precision of sensing can be guaranteed, thereby improving the accuracy and precision of wireless sensing. By digitally modulating the identity information and sensing information onto the frequency conversion signal, the anti-interference capability of the wireless sensing system can be greatly improved. At the same time, this solution combines low-power digital sensing technology with ultra-low-power frequency conversion technology, taking into account both wireless working distance and wireless sensing accuracy. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the variable frequency sensing circuit structure according to an embodiment of the present invention.

[0036] Figure 2 This is a schematic diagram of the operation process of the frequency conversion sensing circuit in a certain time period according to an embodiment of the present invention.

[0037] Figure 3 This is a schematic diagram of the structure of a frequency converter unit according to an embodiment of the present invention.

[0038] Figure 4 This is a schematic diagram of the electrical connection between the frequency conversion unit and the modulation unit in an embodiment of this utility model.

[0039] Figure 5 This is a schematic diagram of the circuit structure of the mixer subunit in an embodiment of the present invention.

[0040] Figure 6 This is a schematic diagram of a circuit structure of a resonator unit according to an embodiment of the present invention.

[0041] Figure 7 This is a schematic diagram of the structure of the wireless sensing circuit in an embodiment of this utility model.

[0042] Figure 8 This is a schematic diagram of the structure of the wireless sensing system according to an embodiment of the present invention. Detailed Implementation

[0043] The specific embodiments of this utility model are described below to enable those skilled in the art to understand this utility model. However, it should be understood that this utility model is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of this utility model as defined and determined by the appended claims, these changes are obvious. All utility model creations utilizing the concept of this utility model are within the scope of protection.

[0044] The frequency conversion sensing circuit 10 provided in one embodiment of this solution is as follows: Figure 1 As shown, it includes a frequency conversion unit 12, a modulation unit 13, a data acquisition and control unit 14, and a sensing unit 15, which are connected in sequence.

[0045] The frequency conversion unit 12 is used to convert a first radio frequency signal having a first frequency (f1) into a frequency conversion signal having a frequency (f2) different from the first frequency;

[0046] The sensing unit 15 is used to sense target sensing data;

[0047] The acquisition and control unit 14 is used to acquire digital sensing data based on target sensing data and to output working instructions to the modulation unit 13;

[0048] The modulation unit 13 modulates the frequency conversion unit 12 according to the working command, thereby loading the modulation information onto the frequency conversion signal.

[0049] The modulation information includes identity encoding data and sensor data.

[0050] The sensing unit 15 can be either an analog sensor or a low-power digital sensor.

[0051] The acquisition and control module 12 has two main functions: first, to acquire digital sensing data, and second, to control the operation of the modulation unit 13.

[0052] When the sensing unit 15 uses an analog sensor, the acquisition and control module 12 converts the analog sensing data sent by the sensing unit 15 into digital sensing data.

[0053] When the sensing unit 15 uses a low-power digital sensor, the acquisition control module 12 receives digital sensing data sent by the low-power digital sensor. The sensing unit 15 can obtain the power required for operation from the acquisition control module 12, or it can obtain the power required for operation from other functional modules (not shown), such as, but not limited to, batteries and DC power supply modules based on ambient energy harvesting.

[0054] The acquisition and control module 12 can be any control device or apparatus capable of generating digitally encoded signals. The acquisition and control module 12 can obtain the electrical energy required for operation from other (not shown) functional modules, including but not limited to batteries and DC power supply modules based on environmental energy harvesting.

[0055] It is understandable that environmental energy includes, but is not limited to, radio frequency energy, light energy, heat energy, temperature difference energy, and vibration energy in free space.

[0056] It is understandable that the acquisition and control module 12 can take various forms 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, an 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.

[0057] Understandably, 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.

[0058] In one example, the acquisition control module 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 on the power of the direct current. It is configured to internally store identification code data and operate according to pre-agreed communication rules. These pre-agreed communication rules can be common RFID communication rules, such as Tag Talk Only (TTO) mode, and are not limited here.

[0059] In one example, such as Figure 2 As shown, this is a schematic diagram of the operation process of the frequency conversion sensing circuit during a certain period. In the first period, the acquisition control module 12 sends an identity code data operation command to the modulation unit 13. The modulation unit 13 modulates the frequency conversion signal generated by the frequency conversion unit 12 according to the operation command, thereby loading the identity code data onto the frequency conversion signal. In the second period, the acquisition control module 12 sends a sensing data operation command to the modulation unit 13. The modulation unit 13 modulates the frequency conversion signal generated by the frequency conversion unit 12 according to the operation command, thereby loading the sensing data onto the frequency conversion signal.

[0060] There are various ways to implement the ultra-low power frequency converter unit 12, for example, such as Figure 3 As shown, the frequency conversion unit 12 includes a mixing subunit 121 and a resonant subunit 122. The mixing subunit 121 includes at least two ports, namely a first port and a second port. The first port is used to input a first radio frequency signal with a first frequency (f1) and output a frequency conversion signal with a frequency different from the first frequency. The second port is electrically connected to the resonant subunit 122.

[0061] The mixer subunit 121 can take many forms; two implementation methods are introduced below.

[0062] In one example, such as Figure 4 As shown, an exemplary schematic diagram of the electrical connection between the frequency conversion unit 12 and the modulation unit 13 is illustrated. The mixing subunit 121 includes a first inductor 1211 and a first varactor diode 1212 connected in series, and the resonant subunit 122 includes a passive piezoelectric resonator 1221.

[0063] The first terminal of the first inductor 1211 serves as the radio frequency signal input / output port. The second terminal of the first inductor 1211 is electrically connected to the first terminal of the first varactor diode 1212, and the second terminal of the first varactor diode 1212 is electrically connected to the first terminal of the passive piezoelectric resonator 1221. The second terminal of the passive piezoelectric resonator 1221 is grounded. The modulation unit 13 includes a first switching element 131. The first terminal of the first switching element 131 is electrically connected to the second terminal of the first inductor 1211 and the first terminal of the first varactor diode 1212, and its second terminal is grounded. In this embodiment, the mixing subunit 121 and the resonator subunit 122 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 conversion signal is the resonant frequency of the resonant oscillator unit 122 (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 repeated here.

[0064] The first switching element 131 can be any element capable of enabling the passage and blocking of radio frequency signals on the line, including but not limited to diodes, metal-oxide-semiconductor field-effect transistors (MOSFETs), bipolar junction transistors (BJTs), or insulated gate bipolar transistors (IGBTs).

[0065] The first switching element 131 operates under a working instruction. When it receives the first working instruction, it performs a first operation and is in a first working state. When it receives the second working instruction, it performs a second operation and is in a second working state.

[0066] In this embodiment, the first working instruction is a disconnect instruction, and the first working state is a disconnect state, that is, the first switching element 131 is in a disconnect state after responding to the first working instruction; the second working instruction is a close instruction, and the second working state is a close state, that is, the first switching element 131 is in a close state after responding to the second working instruction. When the first switching element 131 is in a closed state, the bypass where the first switching element 131 is located is in a low impedance state, and most of the radio frequency signal in the frequency converter unit 12 enters the bypass where the first switching element 131 is located, so the frequency converter unit 12 cannot generate a frequency conversion signal; when the first switching element 131 is in a disconnect state, the bypass where the first switching element 131 is located is in a high impedance state, and the radio frequency signal in the frequency converter unit 12 will not enter the bypass where the first switching element 131 is located, so the frequency converter unit 12 can generate a frequency conversion signal.

[0067] The modulation unit 13 can also be located in other positions of the frequency conversion unit 12, achieving the same effect. As some possible alternatives, the first end of the first switching element 131 is electrically connected to the first end of the first inductor 1211, and the second end of the first switching element 131 is grounded; or, the first end of the first switching element 131 is electrically connected to the first end of the passive piezoelectric resonator 1221, and the second end of the first switching element 131 is grounded.

[0068] The aforementioned passive piezoelectric resonators include, but are not limited to, crystal resonators, ceramic resonators, surface acoustic wave piezoelectric resonators, and MEMS piezoelectric resonators.

[0069] The resonant subunit 122 can adopt other suitable passive resonant circuit forms, including but not limited to, parallel LC resonant circuits and series LC resonant circuits. The parallel LC resonant circuit includes a parallel inductor and a series capacitor. For example, the first end of the parallel inductor is electrically connected to the second end of the frequency converter subunit 121, and its second end is grounded. The first end of the parallel capacitor is electrically connected to the first end of the parallel inductor, and its second end is grounded. The series LC resonant circuit includes a series inductor and a series capacitor. For example, the first end of the series inductor is electrically connected to the second end of the frequency converter subunit 121, and its second end is electrically connected to the first end of the series capacitor. The second end of the series capacitor is grounded.

[0070] In another example, such as Figure 5 As shown, this illustrates the circuit architecture of another mixer subunit 121. Figure 4Based on the embodiment, the mixer subunit 121 further includes a second varactor diode 1213, which is reverse-connected to the first varactor diode 1212. That is, the first end of the second varactor diode 1213 is electrically connected to the second end of the first varactor diode 1212, and the second end of the second varactor diode 1213 is electrically connected to the second port P4 of the mixer subunit 121. The modulation unit 13 includes a first switching element 131, the first end of which is electrically connected to the first end of the first inductor element 1211, and its second end is grounded. The resonator subunit 122 adopts an LC parallel resonant circuit, which includes a first parallel inductor 1222 and a first parallel capacitor 1223. The first end of the first parallel inductor 1222 is electrically connected to the second end of the second varactor diode 1213, and its second end is grounded. The first end of the first parallel capacitor 1223 is electrically connected to the first end of the first parallel inductor 1222, and its second end is grounded.

[0071] Frequency conversion typically requires a certain radio frequency (RF) signal drive power threshold to occur; in other words, the frequency conversion unit 12 can only perform the corresponding frequency conversion process after the RF drive power threshold is met. Therefore, the generation of the frequency conversion signal can be controlled by controlling the RF signal power loss within the frequency conversion unit 12, thereby achieving amplitude shift keying (APS) modulation. For example, this can be achieved through the aforementioned method in a similar manner... Figure 4 This can be achieved by adding a bypass equipped with a modulation module 14 to a certain signal transmission line of the frequency conversion unit 12, or by using the modulation module 14 to control the resonance state of the resonant subunit 122, or by controlling the matching state of the matching circuit in the frequency conversion unit 12.

[0072] In one example, such as Figure 6 As shown, amplitude shift keying is achieved by controlling the resonant state of the resonant sub-unit 122. The resonant sub-unit 122 adopts a parallel LC resonant circuit, including a first parallel inductor 1222 and a first parallel capacitor 1223; the modulation unit 13 includes a first switching element 131; the first terminal of the first switching element 131 is electrically connected to the second terminal of the first parallel inductor 1222, and its second terminal is grounded.

[0073] The first switching element 131 can also be located at other positions in the resonator unit 122. As a possible alternative, the first end of the first switching element 131 is electrically connected to the second end of the mixer subunit 121, and the second end of the first switching element 131 is electrically connected to the first end of the first parallel inductor 1222, with the second end of the first parallel inductor 1222 grounded, and everything else remaining unchanged; or, the first end of the first parallel inductor 1222 is electrically connected to the second end of the mixer subunit 121, with its second end grounded, and the first end of the first switching element 131 is connected to the first parallel inductor 1222. The first terminal of the first switch element 131 is electrically connected to the first terminal of the first parallel capacitor 1223, and the second terminal of the first parallel capacitor 1223 is grounded; or, the first terminal of the first parallel inductor 1222 is electrically connected to the second terminal of the mixer subunit 121, and its second terminal is grounded, the first terminal of the first parallel capacitor 1223 is electrically connected to the first terminal of the first parallel inductor 1222, and the second terminal of the first parallel capacitor 1223 is electrically connected to the first terminal of the first switch element 131, and the second terminal of the first switch element 131 is grounded.

[0074] Those skilled in the art should understand that matching circuits can be provided on each signal transmission path in the above embodiments to reduce the transmission loss of radio frequency signals on each signal transmission path and obtain a better signal-to-noise ratio. The number of matching circuits in the frequency converter circuit can be set according to actual needs to ensure low-loss or even lossless transmission of radio frequency signals on each signal transmission path. At the same time, there are various forms of matching circuits, and the appropriate matching circuit form can be selected as needed, including but not limited to a single inductor, a single capacitor, a combination circuit of several capacitors, a combination circuit of several inductors, and a combination circuit of several capacitors and inductors.

[0075] It should be noted that the inductors 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 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.

[0076] In the foregoing embodiments, the modulation unit 13 is disposed on the signal transmission bypass of the frequency conversion unit 12. Of course, the modulation unit 13 can also be directly disposed on the signal transmission path. For example, the first radio frequency signal enters the first terminal of the mixer subunit 121 after passing through the first switching element 131; or, the first terminal of the first switching element 131 is electrically connected to the mixer subunit 121, and its second terminal is electrically connected to the resonant subunit 122; or, the first terminal of the first switching element 131 is electrically connected to the second terminal of the first inductor element 1211, and its second terminal is electrically connected to the first terminal of the first varactor diode; or, the first terminal of the first switching element 131 is electrically connected to the second terminal of the passive piezoelectric resonator 1221, and its second terminal is grounded. It should be noted that since the modulation unit 13 itself has a certain insertion loss, directly disposing the modulation unit 13 on the signal transmission path results in greater loss. In this solution, it is preferable to use the method of disposing the modulation unit 13 on the signal transmission path bypass.

[0077] In any of the foregoing embodiments, the modulation signal sent by the acquisition control unit 14 to the modulation unit 13 includes identity code data and sensing data, thereby the frequency conversion signal of the frequency conversion circuit carries identity code data and sensing data.

[0078] In the foregoing embodiments, the frequency conversion sensing circuit is a single-port input / output circuit, meaning the first radio frequency signal and the frequency conversion signal share the same port. However, due to the omnidirectional transmission characteristics of the radio frequency signal in the circuit, a multi-port input / output circuit can also be used. For example, the first radio frequency signal can be input from the first terminal of the first inductor element 1211, and the frequency conversion signal can be output from one of the following locations: from a bypass output electrically connected to the first transmission path, or from a bypass output electrically connected to the second transmission path, or from a bypass output electrically connected to the third transmission path, or from a bypass output electrically connected to the fourth transmission path, or from a bypass output electrically connected to the fifth transmission path.

[0079] This solution also provides a wireless sensing circuit 100, such as Figure 7 As shown, it includes an antenna unit 11 and a frequency conversion sensing circuit 10 as described in any of the preceding embodiments, wherein the frequency conversion sensing circuit 10 is electrically connected to the antenna unit 11.

[0080] 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.

[0081] The frequency conversion sensing circuit 10 receives a first radio frequency signal transmitted from the antenna unit 11 and transmits a frequency conversion signal with a modulated frequency different from the first frequency to the antenna unit 11.

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

[0083] Specifically, the modulation unit 13 executes corresponding operations according to the working instructions issued by the acquisition control module 12. For example, upon receiving a first working instruction, it executes a first operation and enters a first working state; upon receiving a second working instruction, it executes a second operation and enters a second working state. The first working state generates a frequency-converted signal, and the second working state does not generate a frequency-converted signal. For example, when the modulation unit 13 is in the first working state, the frequency-converted sensing circuit 10 sends a frequency-converted signal to the antenna unit 11; when the modulation unit 13 is in the second working state, the frequency-converted sensing circuit 10 does not send a frequency-converted signal to the antenna unit 11.

[0084] The above process achieves the following positive technical effects: First, by employing a different frequency communication system, it overcomes the problems of short communication distance and severe co-frequency interference inherent in the same frequency communication system. Second, by loading identity code data and sensor data into the returned frequency conversion signal, it enables accurate identification and positioning of numerous wireless sensor terminals within the communication coverage area of ​​the transceiver device, overcoming the limitation on the number of wireless sensor terminals that can be carried by the same transceiver device under the existing different frequency communication system. Third, the use of digital sensor data ensures sensing accuracy and precision, thereby improving the accuracy and precision of wireless sensing. Fourth, by digitally modulating identity code data and sensor data onto the frequency conversion signal, it greatly enhances the anti-interference capability of the wireless sensing system. The wireless sensing circuit in this solution, by employing extremely low-power frequency conversion technology combined with low-power digital sensing technology, ensures both wireless sensing accuracy and precision while also considering the wireless working distance.

[0085] 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.

[0086] In some embodiments, the acquisition control unit 14 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 microcontrollers, operate under direct current conditions. These components are 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 Tag Talk Only (TTO) mode, or the anti-collision method described in prior patent application CN200910095463.X. This solution does not limit the specific communication rules.

[0087] This solution also provides a wireless sensing device 300, which includes a housing and the wireless sensing circuit 100 disclosed in any of the foregoing embodiments. All or part of the wireless terminal circuit is housed within the housing, which protects the wireless terminal circuit to improve its mechanical performance, environmental performance, and service life.

[0088] In some embodiments, the wireless sensing circuit 100 is entirely disposed inside 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.

[0089] In some implementations, the antenna unit 11 of the wireless sensing circuit 100 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.

[0090] This solution also provides a wireless sensing system, such as Figure 8 As shown, it includes a transceiver 200 and several wireless sensing devices 300 disclosed in any of the foregoing embodiments.

[0091] The transceiver 200 is used to send a first frequency (f1) radio frequency signal to the wireless sensing device 300, and to receive a frequency-converted signal from the wireless sensing device 300 that is different from the first frequency and meets preset communication rules.

[0092] The frequency conversion signal can carry identity code data and sensor data.

[0093] This solution also provides a wireless tag method, which is based on the aforementioned wireless sensing system, and the main steps are as follows:

[0094] S1, the transceiver 200 transmits a first radio frequency signal having a first frequency;

[0095] S2, the wireless sensing device 300 receives a first radio frequency signal with a first frequency and returns a modulated frequency-converted signal to the transceiver 200;

[0096] S3, the transceiver 200 receives and analyzes the frequency conversion signal to obtain frequency conversion information.

[0097] In step S1, the first radio frequency signal sent by the transceiver 200 is used to provide radio frequency energy to the wireless sensing device 300 within a specific communication range, thereby waking up the wireless sensing device 300 to work.

[0098] In step S2, the wireless sensing device 300 receives the first radio frequency signal and returns a modulated frequency conversion signal under a preset communication rule.

[0099] In step S3, the transceiver 200 receives the modulated frequency conversion signal and obtains the frequency conversion information by analyzing the frequency conversion signal.

[0100] The frequency conversion signal can carry identity code data and sensor data.

[0101] The present invention uses specific embodiments to illustrate the principles and implementation methods of the present invention. The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

[0102] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of this invention, and should be understood that the scope of protection of this invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on these technical teachings disclosed in this invention without departing from the essence of this invention, and these modifications and combinations are still within the scope of protection of this invention.

Claims

1. A frequency conversion sensing circuit (10), characterized in that, It includes a frequency converter (12), a modulation unit (13), a data acquisition and control unit (14), and a sensing unit (15) connected in sequence, wherein: The frequency conversion unit (12) is used to convert a first radio frequency signal with a first frequency into a frequency conversion signal with a frequency different from the first frequency; The sensing unit (15) is used to sense target sensing data; The acquisition control unit (14) is used to acquire digital sensing data based on the target sensing data and to output working instructions to the modulation unit (13); The modulation unit (13) is used to modulate the frequency conversion unit (12) according to the working instructions, thereby loading the modulation information onto the frequency conversion signal; The frequency conversion unit (12) includes a mixing subunit (121) and a resonant subunit (122). The mixing subunit (121) includes at least two ports, wherein the first port is used to input a first radio frequency signal with a first frequency and output a frequency conversion signal with a frequency different from the first frequency, and the second port is electrically connected to the resonant subunit (122).

2. The frequency conversion sensing circuit according to claim 1, characterized in that, The mixing subunit (121) includes one of the following schemes: Option 1: The mixing subunit (121) includes a first inductor (1211) and a first varactor diode (1212) connected in series. The first end of the first inductor (1211) serves as a radio frequency signal input port, and the radio frequency signal transmission path is denoted as the first transmission path. The second end of the first inductor (1211) is electrically connected to the first end of the first varactor diode (1212), and the radio frequency signal transmission path is denoted as the second transmission path. The second end of the first varactor diode (1212) is electrically connected to the first end of the resonator unit (122), and the radio frequency signal transmission path is denoted as the third transmission path. Option 2: The mixing subunit (121) includes a first inductor (1211), a first varactor diode (1212), and a second varactor diode (1213) connected in series. The first end of the first inductor (1211) serves as the radio frequency signal input port, and the radio frequency signal transmission path is denoted as the first transmission path. The second end of the first inductor (1211) is electrically connected to the first end of the first varactor diode (1212), and the radio frequency signal transmission path is denoted as the second transmission path. The second end of the second varactor diode (1213) is electrically connected to the second end of the first varactor diode (1212), and the radio frequency signal transmission path is denoted as the fourth transmission path. The first end of the second varactor diode (1213) is electrically connected to the resonator unit (122), and the radio frequency signal transmission path is denoted as the fifth transmission path.

3. The frequency conversion sensing circuit according to claim 2, characterized in that, The modulation unit (13) includes a first switching element (131); In Scheme 1, the first switching element is located in one of the following positions: It is set on the bypass of one of the first to third transmission paths; or, it is set inside the resonator unit; or, a matching circuit is set at one of the first to third transmission paths, and the first switching element is set inside the matching circuit. In Scheme 2, the first switching element is located in one of the following positions: A bypass is provided on one of the first, second, fourth, and fifth transmission paths; or, it is provided inside the resonator unit; or, a matching circuit is provided at one of the first, second, fourth, and fifth transmission paths, and the first switching element is provided inside the matching circuit.

4. The frequency conversion sensing circuit according to claim 2, characterized in that, In Scheme 1, the frequency converter signal is output through a bypass of one of the first to third transmission paths; in Scheme 2, the frequency converter signal is output through a bypass of one of the first, second, fourth, and fifth transmission paths.

5. The frequency conversion sensing circuit according to claim 1, characterized in that, The resonator unit (122) includes a passive piezoelectric resonator, or an equivalent LC parallel resonant circuit, or an equivalent LC series resonant circuit.

6. The frequency conversion sensing circuit according to any one of claims 1-5, characterized in that, The frequency conversion signal may carry sensor data, identity code data, or a combination of both.

7. A wireless frequency conversion sensing circuit (100), characterized in that, The system includes an antenna unit (11) and a frequency conversion sensing circuit (10) as described in any one of claims 1-6, wherein the frequency conversion sensing circuit (10) is electrically connected to the antenna unit (11), and wherein: The antenna element (11) 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; The frequency conversion sensing circuit (10) receives a first radio frequency signal sent from the antenna unit (11) and sends a frequency conversion signal with a modulated frequency different from the first frequency to the antenna unit (11).

8. A wireless sensing device (300), characterized in that, It includes a housing and the wireless frequency conversion sensing circuit (100) as described in claim 7, wherein all or part of the wireless frequency conversion sensing circuit (100) is disposed in the housing.

9. The wireless sensing device according to claim 8, characterized in that, The wireless frequency conversion sensing circuit (100) is entirely housed inside the encapsulation housing, and at least the positions corresponding to the antenna elements (11) on the encapsulation housing are made of wave-transparent material; or, The antenna unit (11) of the wireless frequency conversion sensing circuit (100) is located outside the encapsulation housing, while the other units are located inside the encapsulation housing. The encapsulation housing is provided with a communication interface that is electrically connected to the antenna unit (11).

10. A wireless sensing system, characterized in that, The device includes a transceiver (200) and a plurality of wireless sensing devices (300) as described in any one of claims 8-9, wherein the transceiver (200) is used to send a first frequency radio frequency signal to the wireless sensing device (300) and to receive a frequency-converted signal from the wireless sensing device (300) that satisfies a preset communication rule and is transmitted at a frequency different from the first frequency.

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