Microwave direct-drive frequency conversion circuit, terminal, system and method

Abstract

The application belongs to the technical field of Internet of Things sensing systems, and specifically discloses a microwave direct-drive frequency conversion circuit, a terminal, a system and a method. The circuit comprises scheme one: a modulation element, a following resonance unit and a sensing resonance unit, and the modulation element is connected with the following resonance unit and the sensing resonance unit respectively; or scheme two: a modulation element, a following resonance unit and a sensing resonance unit, the following resonance unit is connected with the modulation element, and the sensing resonance unit is connected with the modulation element and the following resonance unit simultaneously, so that a microwave signal transmission path from the following resonance unit to the sensing resonance unit without passing through the modulation element is established. By setting the first resonance frequency of the following resonance unit and the second resonance frequency of the sensing resonance unit to change in the same direction with the change of the target sensing quantity, the technical scheme can realize distance expansion and maintain sensing precision in a wide working frequency range.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of Internet of Things sensing systems, and relates to a microwave direct-drive frequency conversion circuit, a terminal, a system and a method. BACKGROUND

[0002] At present, in the Internet of Things, sensing systems are often used for environmental data collection, monitoring and early warning. According to the different transmission methods and technologies, the commonly used sensing systems in the Internet of Things can be divided into the following categories:

[0003] Wired sensing system: This type of sensing system uses wired connection to connect sensors to the network, commonly using Ethernet, RS-485, USB and other interfaces. The wired transmission system has the advantages of stability, reliability and strong anti-interference ability, but is limited by wiring and is not suitable for application scenarios with high flexibility requirements.

[0004] Wireless sensing system: This type of sensing system uses wireless communication technology to transmit sensor data to the network. Common wireless transmission technologies include Wi-Fi, Bluetooth, Zigbee, LoRa, etc. Wireless transmission systems have the advantages of simple wiring, flexibility, etc., and are suitable for environments where wiring is difficult or not possible. However, many wireless sensing systems still rely on battery power, which leads to limitations on battery life and frequent battery replacement. For large-scale sensor networks, maintenance costs and operational complexity increase.

[0005] Currently, some people have proposed using passive wireless sensing systems to solve the above problems. Common passive wireless transmission technologies include RFID, SAW, etc. Passive wireless sensing systems use environmental energy such as light, vibration or radio waves to power sensors, thereby eliminating the need for batteries. This system can capture environmental energy through an energy harvester and convert it into the electrical energy required by the sensor. By eliminating the need for battery replacement, passive wireless sensing systems can reduce maintenance costs and provide long-term stable operation.

[0006] The existing common passive Internet of Things sensing technology such as RFID often has the same frequency for uplink and downlink carrier signals, which is easy to cause the gateway to be unable to transmit high power due to the same frequency blockage, the energy received by the tag end is limited, and the wireless communication distance is limited, etc. Realistic difficulties, and the above difficulties are difficult to overcome. SAW sensors use analog signal mode, are easily disturbed, rely on frequency differentiation, are prone to string reading, and have relatively low accuracy.

[0007] In addition, in some existing passive wireless frequency conversion sensing technologies, two resonant networks are usually arranged, a first resonant network is connected with a sensing element, and a second resonant network has a fixed resonant frequency. A resonant frequency difference between the first resonant network and the second resonant network usually has a matching working range. When the resonant frequency difference exceeds the matching working range, the power of the returned frequency conversion signal or the conversion efficiency will be greatly reduced, affecting the wireless sensing accuracy and distance. SUMMARY

[0008] The present application aims to provide a microwave direct drive frequency conversion circuit, terminal, system and method to solve the problems of same frequency blocking and limited communication distance.

[0009] In order to achieve the above-mentioned purpose, the basic scheme of the present application is as follows: a microwave direct drive frequency conversion circuit comprising one of the following schemes:

[0010] Scheme one:

[0011] comprising a modulation element, a following resonant unit and a sensing resonant unit, the modulation element being connected with the following resonant unit and the sensing resonant unit respectively;

[0012] the modulation element is configured to receive a first microwave signal having a first frequency and output a frequency conversion signal having a second frequency;

[0013] the following resonant unit is configured to have a first resonant frequency;

[0014] the sensing resonant unit is configured to collect a target sensing quantity and has a second resonant frequency;

[0015] The first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit change in the same direction with the change of the target sensing quantity, so as to ensure that the frequency difference between the first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit is always within the matching working range;

[0016] Scheme two:

[0017] comprising a modulation element, a following resonant unit and a sensing resonant unit, the following resonant unit being connected with the modulation element, the sensing resonant unit being connected with the modulation element and the following resonant unit at the same time, and a microwave signal transmission path from the following resonant unit to the sensing resonant unit without passing through the modulation element being established;

[0018] the modulation element is configured to receive a first microwave signal having a first frequency and output a frequency conversion signal having a second frequency;

[0019] the following resonant unit is configured to have a first resonant frequency;

[0020] The sensing resonant unit is configured to acquire the target sensing quantity and has a second resonant frequency;

[0021] The first resonant frequency of the follow resonant unit and the second resonant frequency of the sensing resonant unit both change in the same direction as the target sensing quantity changes, keeping the frequency difference between the first resonant frequency and the second resonant frequency always within the matching working range.

[0022] The working principle and beneficial effects of this basic scheme are as follows: This technical scheme adopts a different frequency communication system for transmitting and receiving. By setting the first resonant frequency of the follower resonant unit and the second resonant frequency of the sensing resonant unit to change in the same direction with the change of the target sensing quantity, the frequency difference between the first resonant frequency and the second resonant frequency can always be kept within the matching working range, thereby achieving the goal of extending the wireless working distance while maintaining sensing accuracy over a wide working frequency range.

[0023] Furthermore, the size of the matching working range is positively correlated with the size of the first frequency.

[0024] The matching working range is adjusted based on the first frequency, making it easy to use.

[0025] Furthermore, in Option 1,

[0026] The sensing resonant unit includes a first piezoelectric resonator;

[0027] The follower resonant unit includes a first inductor and a first capacitor;

[0028] The sensing resonant unit responds to the environmental sensing quantity and outputs a microwave or radio frequency signal with a second resonant frequency that varies with the target sensing quantity.

[0029] The first capacitance changes with the target sensing quantity, and the change of the first capacitance makes the direction of change of the first resonant frequency of the follower resonant unit the same as the direction of change of the second resonant frequency of the sensing resonant unit, so that the frequency difference between the first resonant frequency of the follower resonant unit and the second resonant frequency of the sensing resonant unit is within the matching working range.

[0030] It has a simple structure and is easy to operate.

[0031] Furthermore, based on the changes in the resonant frequencies of the sensing resonant unit and the follower resonant unit in the first and second states, the changes in the capacitance value ΔC of the first capacitor in the follower resonant unit and the changes in the resonant frequency Δf of the sensing resonant unit are obtained. Cr2 The relationship between them, i.e. Where f r1 C is the first resonant frequency of the follower resonant unit in the first state, and C is the capacitance value of the first capacitor in the follower resonant unit in the first state.

[0032] And / or, according to the resonance frequency variation of the sensing resonant unit and the following resonant unit in the first state and the second state, the relationship between the inductance value variation ΔL of the first inductor in the following resonant unit and the resonance frequency variation Δf of the sensing resonant unit is obtained, that is, Lr2 Where f r1 is the first resonance frequency of the following resonant unit in the first state, and L is the inductance value of the first inductor in the following resonant unit in the first state.

[0033] The first capacitor can change with the target sensing amount, and the change of the first capacitor makes the change direction of the first resonance frequency of the following resonant unit and the change direction of the second resonance frequency of the sensing resonant unit the same, so that the frequency difference between the first resonance frequency of the following resonant unit and the second resonance frequency of the sensing resonant unit is within the matching working range.

[0034] Further, in scheme one, the following resonant unit includes a passive piezoelectric resonator, the resonance frequency of the passive piezoelectric resonator changes with the target sensing amount, and the resonance frequency variation Δf r1 of the following resonant unit is equal to the resonance frequency variation Δf r2 of the sensing resonant unit.

[0035] The resonance frequency of the passive piezoelectric resonator changes with the target sensing amount, which guarantees that the frequency difference between the first resonance frequency and the second resonance frequency is within the matching working range.

[0036] Further, in scheme one, the sensing resonant unit includes a resonator and a sensing element, the resonator is connected with the sensing element;

[0037] The resonance frequency of the resonator does not change with the environmental parameter, and the capacitance value of the sensing element changes with the environmental sensing amount, so that the second resonance frequency of the sensing resonant unit formed by the resonator and the sensing element changes with the target sensing amount;

[0038] The following resonant unit adopts a resonant network, including a first inductor and a first capacitor, and the capacitance value of the first capacitor changes with the target sensing amount, so that the frequency difference between the first resonance frequency of the following resonant unit and the second resonance frequency of the sensing resonant unit is within the matching working range.

[0039] The capacitance value of the first capacitor can change with the target sensing amount, so that the frequency difference between the first resonance frequency of the following resonant unit and the second resonance frequency of the sensing resonant unit is within the matching working range.

[0040] Further, in scheme two, the following resonant unit includes a third passive piezoelectric resonator, and the sensing resonant unit includes a first passive piezoelectric resonator;

[0041] ​The modulation element is connected with the first end of the third passive piezoelectric resonator and the first end of the first passive piezoelectric resonator respectively, and the second end of the third passive piezoelectric resonator is connected with the second end of the first passive piezoelectric resonator;

[0042] The first passive piezoelectric resonator responds to the environmental sensing quantity and outputs a microwave or radio frequency signal of a second resonant frequency which changes with the target sensing quantity, and the third passive piezoelectric resonator changes with the target sensing quantity, so that the frequency difference between the first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit is within the matching working range.

[0043] The devices are matched so that the frequency difference between the first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit is within the matching working range.

[0044] Further, in the second scheme, the following resonant unit comprises a fourth passive piezoelectric resonator and a second capacitor, and the sensing resonant unit comprises a first passive piezoelectric resonator and a capacitive sensing element;

[0045] The modulation element is connected with the first end of the fourth passive piezoelectric resonator and the first end of the second passive piezoelectric resonator respectively, and the second end of the fourth passive piezoelectric resonator is connected with the second end of the second passive piezoelectric resonator;

[0046] The first end of the capacitive sensing element and the first end of the second passive piezoelectric resonator are connected with the modulation element, and the second end is grounded;

[0047] The first end of the first capacitor and the first end of the fourth passive piezoelectric resonator are connected with the modulation element, and the second end is grounded;

[0048] The resonant frequency of the second passive piezoelectric resonator does not change with the environmental parameter, and the capacitance value of the capacitive sensing element changes with the environmental sensing quantity, so that the second resonant frequency of the sensing resonant unit changes with the target sensing quantity;

[0049] The capacitance value of the first capacitor changes with the target sensing quantity, so that the frequency difference between the first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit is within the matching working range.

[0050] The devices are used to control the frequency difference between the first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit to be within the matching working range.

[0051] Further, in the second scheme, the following resonant unit comprises a first inductor and a first capacitor in series, and the sensing resonant unit comprises a second passive piezoelectric resonator and a capacitive sensing element;

[0052] The modulation element is connected with the first end of the second passive piezoelectric resonator and the first end of the first inductor respectively, the second end of the first inductor is connected with the first end of the first capacitor, and the second end of the first capacitor is connected with the second end of the second passive piezoelectric resonator.

[0053] The first end of the capacitive sensing element is connected with the second end of the second passive piezoelectric resonator and the second end of the first capacitor, wherein the first capacitor changes with the target sensing quantity, so that the frequency difference between the first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit is within the matching working range.

[0054] The first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit are set to change in the same direction with the change of the target sensing quantity, so that the frequency difference between the first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit is within the matching working range.

[0055] Further, in the second scheme, the following resonant unit includes a first inductor, a second capacitor and a first capacitor, and the sensing resonant unit includes a second inductor, a third capacitor and an inductive sensing element.

[0056] The modulation element is connected with the first end of the second inductor and the first end of the first inductor respectively, the second end of the first inductor is connected with the first end of the second capacitor, and the second end of the second capacitor is connected with the second end of the third capacitor.

[0057] The first end of the inductive sensing element is connected with the modulation element, and the second end is grounded.

[0058] The first end of the first capacitor is connected with the first end of the first inductor, and the second end is grounded, wherein the first capacitor changes with the target sensing quantity, so that the frequency difference between the first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit is within the matching working range.

[0059] The inductive and capacitive devices are used to control the frequency difference between the first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit within the matching working range.

[0060] Further, the modulation element includes at least three modulation ports, the first modulation port is used to input a first microwave signal with a first frequency, and output a frequency conversion signal with a second frequency.

[0061] The following resonant unit is connected with the second modulation port, and the sensing resonant unit is connected with the third modulation port.

[0062] The modulation element has simple structure and is convenient to connect.

[0063] The application further provides a microwave direct-drive frequency conversion terminal, comprising the microwave direct-drive frequency conversion circuit and a first antenna connected with the microwave direct-drive frequency conversion circuit.

[0064] The first antenna is used for coupling to receive a first microwave signal with a first frequency from a free space and coupling to output a frequency conversion signal with a second frequency from the microwave direct-drive frequency conversion circuit to the free space.

[0065] The terminal has simple structure and is convenient to use.

[0066] The application further provides a microwave direct-drive frequency conversion system, comprising a transceiver device and a plurality of microwave direct-drive frequency conversion terminals, wherein the transceiver device is used for sending a first microwave signal to the microwave direct-drive frequency conversion terminal and receiving a frequency conversion signal with a second frequency returned by the microwave direct-drive frequency conversion terminal meeting a communication rule.

[0067] The system uses the transceiver device and the terminal and adopts a transceiver different frequency communication system, so that the problems of short communication distance and serious same frequency interference existing in a transceiver same frequency communication system can be overcome.

[0068] The application further provides a microwave direct-drive frequency conversion sensing method based on the microwave direct-drive frequency conversion system, comprising the following steps.

[0069] S1, the transceiver device sends a first microwave signal with a first frequency;

[0070] S2, the microwave direct-drive frequency conversion terminal receives the first microwave signal with the first frequency and returns a frequency conversion signal with a second frequency carrying sensing information to the transceiver device;

[0071] S3, the transceiver device receives and analyzes the frequency conversion signal to obtain the sensing information.

[0072] The method sets the first resonance frequency of the following resonance unit and the second resonance frequency of the sensing resonance unit to change in the same direction with the change of the target sensing amount, so that the frequency difference between the first resonance frequency and the second resonance frequency is kept in a matching working range at all times. BRIEF DESCRIPTION OF DRAWINGS

[0073] Figure 1 is a structure schematic diagram of scheme one of the first embodiment of the microwave direct-drive frequency conversion circuit of the application;

[0074] Figure 2 is a resonance frequency change curve diagram of the following resonance unit and the sensing resonance unit in two states of scheme one of the first embodiment of the microwave direct-drive frequency conversion circuit of the application;

[0075] Figure 3 is a structure schematic diagram of scheme two of the first embodiment of the microwave direct-drive frequency conversion circuit of the application;

[0076] Figure 4 is a structure diagram of the sensing resonant unit in the first scheme of the first embodiment of the microwave direct-drive frequency conversion circuit of the present application;

[0077] Figure 5 is a structure diagram of the first scheme of the second embodiment of the microwave direct-drive frequency conversion circuit of the present application;

[0078] Figure 6 is a structure diagram of the second scheme of the third embodiment of the microwave direct-drive frequency conversion circuit of the present application;

[0079] Figure 7 is a structure diagram of the second scheme of the fourth embodiment of the microwave direct-drive frequency conversion circuit of the present application;

[0080] Figure 8 is a structure diagram of the second scheme of the fifth embodiment of the microwave direct-drive frequency conversion circuit of the present application;

[0081] Figure 9 is a structure diagram of the second scheme of the sixth embodiment of the microwave direct-drive frequency conversion circuit of the present application;

[0082] Figure 10 is a structure diagram of the second scheme of the seventh embodiment of the microwave direct-drive frequency conversion circuit of the present application;

[0083] Figure 11 is a structure diagram of the microwave direct-drive frequency conversion terminal of the present application;

[0084] Figure 12 is a structure diagram of the microwave direct-drive frequency conversion system of the present application.

[0085] The reference signs in the attached drawings of the specification include: microwave direct-drive frequency conversion circuit 10, modulation element 11, following resonant unit 12, sensing resonant unit 13, first antenna 20;

[0086] microwave direct-drive frequency conversion terminal 100, first inductor 121, first capacitor 122, third passive piezoelectric resonator 123, second capacitor 124, third inductor 125, fourth passive piezoelectric resonator 128, first passive piezoelectric resonator 131, second passive piezoelectric resonator 132, capacitive sensing element 133, inductive sensing element 134, second inductor 135, third capacitor 136, transceiver 200. DETAILED DESCRIPTION

[0087] Embodiments of the present application are described below in detail with reference to the accompanying drawings, wherein the same or similar components are denoted by the same or similar reference numerals throughout the drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be understood as limiting the present application.

[0088] In the description of the present application, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0089] In the description of the present application, unless otherwise specified and limited, it should be noted that the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be mechanical connection or electrical connection, it can be the communication between two elements, it can be direct connection or indirect connection through intermediate medium, and the specific meaning of the above terms can be understood by those skilled in the art according to the specific circumstances.

[0090] The present application discloses a microwave direct drive frequency conversion circuit, aiming at the practical problems of existing technology, such as same frequency blocking and limited communication distance, the present application focuses on realizing passive Internet of Things sensing technology with distance expansion and sensing accuracy in wide working frequency range.

[0091] Embodiment one:

[0092] The microwave direct drive frequency conversion circuit comprises one of the following schemes:

[0093] As shown in Figure 1 Scheme one:

[0094] comprises a modulation element 11, a following resonance unit 12 and a sensing resonance unit 13, and the modulation element 11 is electrically connected with the following resonance unit 12 and the sensing resonance unit 13 respectively. The modulation element 11 is configured to receive a first microwave signal with a first frequency (f1) and output a frequency conversion signal with a second frequency (f2).

[0095] The following resonance unit 12 is configured to have a first resonance frequency (f r1 ), and the sensing resonance unit 13 is configured to collect a target sensing quantity and has a second resonance frequency (f r2 ).

[0096] When the target sensing quantity changes, the first resonant frequency of the following resonant unit 12 and the second resonant frequency of the sensing resonant unit 13 change in the same direction with the change of the target sensing quantity, ensuring that the frequency difference between the first resonant frequency of the following resonant unit 12 and the second resonant frequency of the sensing resonant unit 13 is always within the matching working range, thereby achieving the extension of the wireless working distance while maintaining the sensing accuracy in a wide working frequency range.

[0097] As shown in Figure 2 , the resonant frequency change of the following resonant unit 12 and the sensing resonant unit 13 in two states, where the left curve in state 1 is the resonant curve of the sensing resonant unit 13, and the right curve in state 1 is the resonant curve of the following resonant unit 12; when the target sensing quantity changes, the resonant curve of the sensing resonant unit 13 changes and shifts to the left curve in state 2, at this time the frequency difference between the second resonant frequency of the sensing resonant unit 13 in state 2 and the first resonant frequency of the following resonant unit 12 in state 1 is out of the matching working range, if the first resonant frequency of the following resonant unit 12 is fixed, the conversion efficiency of the frequency conversion signal in state 2 will be sharply deteriorated, and even the frequency conversion signal carrying sensing information cannot be generated, resulting in the failure of the sensing function.

[0098] If the first resonant frequency of the following resonant unit 12 also changes in the same direction with the second resonant frequency of the sensing resonant unit 13 with the change of the target sensing quantity (for example, the right resonant curve in state 2), the frequency difference between the first resonant frequency of the following resonant unit 12 and the second resonant frequency of the sensing resonant unit 13 in state 2 can be ensured to be within the matching working range, thereby ensuring the high conversion efficiency of the frequency conversion signal in state 2.

[0099] The working principle of the microwave direct drive frequency conversion circuit 10 can refer to the prior patent application CN202411053036.6, wherein the frequency conversion signal with the second frequency (f2) is obtained by mixing the microwave signal with the second resonant frequency (f r2 ) and the first microwave signal with the first frequency (f1) in the modulation element, i.e. f2=f1±n*f r2 , where n is a positive integer.

[0100] As shown in Figure 3 , scheme two:

[0101] The modulation element 11, the following resonant unit 12 and the sensing resonant unit 13 are connected in series, the following resonant unit 12 is electrically connected with the modulation element 11, the sensing resonant unit 13 is electrically connected with the modulation element 11 and the following resonant unit 12, and a microwave signal transmission path from the following resonant unit 12 to the sensing resonant unit 13 without passing through the modulation element 11 is established, so that the power loss of the microwave signal in the frequency conversion circuit can be reduced, the power of the frequency conversion signal can be improved, and the microwave driving power threshold can be reduced correspondingly.

[0102] The modulation element 11 is configured to receive a first microwave signal with a first frequency and output a frequency conversion signal with a second frequency. The following resonant unit 12 is configured to have a first resonant frequency, and the sensing resonant unit 13 is configured to collect a target sensing quantity and have a second resonant frequency.

[0103] The first resonant frequency of the following resonant unit 12 and the second resonant frequency of the sensing resonant unit 13 change in the same direction with the change of the target sensing quantity, and the frequency difference between the first resonant frequency and the second resonant frequency is always within a matching working range.

[0104] Preferably, the size of the matching working range is positively correlated with the size of the first frequency, for example, when the first frequency is 13.56 MHz, the matching working range is not greater than 1 MHz; when the first frequency is 2.4 GHz, the matching working range is not greater than 20 MHz. The first microwave signal can be any microwave signal with a suitable first frequency, and the first frequency can be an unlicensed frequency band open to industrial, scientific and medical institutions, or a conventional radio frequency identification frequency band, for example, the first frequency can be 125 KHz, 13.56 MHz, 433 MHz, 800 MHz, 900 MHz, 950 MHz, 2.4 GHz or 5.8 GHz, etc.

[0105] More preferably, the modulation element 11 includes at least three modulation ports, a first modulation port is used to input a first microwave signal with a first frequency (f1) and output a frequency conversion signal with a second frequency (f2). The following resonant unit 12 is electrically connected with a second modulation port, and the sensing resonant unit 13 is electrically connected with a third modulation port. The modulation element 11 can be a transistor with a heterojunction, for example, a heterojunction bipolar transistor, a field effect transistor (FET), etc. The FET can be a metal oxide semiconductor field effect transistor (MOSFET), a two-dimensional electron gas transistor or a high electron mobility transistor (HEMT).

[0106] In a preferred scheme of the present application, for example, Figure 4As shown, in Scheme 1, the sensing resonant unit 13 includes a first piezoelectric resonator 131. The resonant frequency of the first piezoelectric resonator 131 can change with the target sensing quantity. In other words, the first piezoelectric resonator 131 serves as both a sensing element and a frequency selection element. The follower resonant unit 12 adopts an LC resonant network and includes a first inductor 121 and a first capacitor 122. The sensing resonant unit 13 responds to the environmental sensing quantity and outputs a microwave or radio frequency signal with a second resonant frequency that changes with the target sensing quantity.

[0107] First capacitor 122 (e.g., attached) Figure 4 The variable capacitor in the first capacitor 122 changes with the target sensing quantity, and the change of the first capacitor 122 makes the change direction of the first resonant frequency of the following resonant unit 12 the same as the change direction of the second resonant frequency of the sensing resonant unit 13, so that the frequency difference between the first resonant frequency of the following resonant unit 12 and the second resonant frequency of the sensing resonant unit 13 is within the matching working range.

[0108] As a possible alternative, the first inductor 121 changes with the target sensing quantity. The change of the first inductor 121 makes the direction of change of the first resonant frequency of the follower resonant unit 12 the same as the direction of change of the second resonant frequency of the sensing resonant unit 13, so that the frequency difference between the first resonant frequency of the follower resonant unit 12 and the second resonant frequency of the sensing resonant unit 13 is within the matching working range.

[0109] Preferably, based on the changes in the resonant frequencies of the sensing resonant unit 13 (first passive piezoelectric resonator 131) and the follower resonant unit 12 (LC resonant network) in the first state (state 1) and the second state (state 2), the change in capacitance ΔC of the first capacitor 122 in the follower resonant unit 12 and the change in resonant frequency Δf of the sensing resonant unit 13 can be obtained. Cr2 The relationship between them, i.e. Where f r1 C is the first resonant frequency of the follower resonant unit 12 in the first state, and C is the capacitance value of the first capacitor 122 in the follower resonant unit 12 in the first state.

[0110] And / or, based on the changes in the resonant frequencies of the sensing resonant unit 13 and the follower resonant unit 12 in the first and second states, the changes in the inductance value ΔL of the first inductor 121 in the follower resonant unit 12 and the changes in the resonant frequency Δf of the sensing resonant unit 13 are obtained. Lr2 The relationship between them, i.e. Where f r1 L is the first resonant frequency of the follower resonant unit 12 in the first state, and L is the inductance value of the first inductor 121 in the follower resonant unit 12 in the first state.

[0111] More preferably, the passive piezoelectric resonator can be any passive resonator that operates based on the piezoelectric effect, such as passive piezoelectric resonators including but not limited to piezoelectric crystal resonators, ceramic resonators, surface acoustic wave resonators, etc.

[0112] In another preferred embodiment of the present invention, in embodiment one, the follower resonant unit 12 includes a passive piezoelectric resonator, the resonant frequency of which changes with the target sensing quantity, and the resonant frequency change Δf_r1 of the follower resonant unit 12 is equal to the resonant frequency change Δf_r2 of the sensing resonant unit 13.

[0113] Example 2:

[0114] like Figure 5 As shown, in Scheme 1, the sensing resonant unit 13 includes a resonator (specifically, a second passive piezoelectric resonator 132), or other resonant circuit structures, such as a series LC resonant network, a series RC resonant network, or a parallel LC resonant network. The sensing resonant unit 13 also includes a sensing element (specifically, an inductive sensing element 134, a capacitive sensing element 133, etc.). The second passive piezoelectric resonator 132 is connected in series with the inductive sensing element 134, and the other end of the inductive sensing element 134 is grounded.

[0115] Alternatively, the first end of the second passive piezoelectric resonator 132 is electrically connected to the modulation element 11, and its second end is grounded. The first end of the inductive sensing element 134 is electrically connected to the first end of the second passive piezoelectric resonator 132 and the modulation element 11, and the second end of the inductive sensing element 134 is grounded.

[0116] Alternatively, a current-type sensor or a voltage-type sensor can be used, with the first terminal of the current-type sensor or voltage-type sensor electrically connected to the first terminal of the second passive piezoelectric resonator 132 and the modulation element 11, and the second terminal of the second passive piezoelectric resonator 132 grounded. Alternatively, the first terminal of the current-type sensor or voltage-type sensor and the series LC resonant network can be electrically connected to the modulation element 11, and the second terminal of the series LC resonant network can be grounded; alternatively, the first terminal of the current-type sensor or voltage-type sensor and the parallel LC resonant network can be electrically connected to the modulation element 11, and the second terminal of the parallel LC resonant network can be grounded.

[0117] In this embodiment, the resonant frequency of the resonator (i.e., the second passive piezoelectric resonator 132) does not change with the environmental parameters. The capacitance value of the sensing element changes in response to the environmental sensing quantity, so that the second resonant frequency of the sensing resonant unit 13 changes with the target sensing quantity.

[0118] The following resonant unit 12 adopts LC resonant network, including first inductance 121 and first capacitance 122, wherein the capacitance value of first capacitance 122 changes with the target sensing quantity, so that the frequency difference between the first resonant frequency of the following resonant unit 12 and the second resonant frequency of the sensing resonant unit 13 is within the matching working range.

[0119] As a possible alternative, the following resonant unit 12 adopts LC resonant network, including first inductance 121 and first capacitance 122, wherein the inductance value of first inductance 121 changes with the target sensing quantity, so that the frequency difference between the first resonant frequency of the following resonant unit 12 and the second resonant frequency of the sensing resonant unit 13 is within the matching working range.

[0120] Embodiment three:

[0121] As shown in the following Figure 6 Resonant unit 12 includes third passive piezoelectric resonator 123, and sensing resonant unit 13 includes first passive piezoelectric resonator 131.

[0122] The modulation element 11 is electrically connected to the first end of the third passive piezoelectric resonator 123 and the first end of the first passive piezoelectric resonator 131 respectively, and the second end of the third passive piezoelectric resonator 123 is electrically connected to the second end of the first passive piezoelectric resonator 131.

[0123] The first passive piezoelectric resonator 131 responds to the environmental sensing quantity and outputs the microwave or radio frequency signal of the second resonant frequency which changes with the target sensing quantity, and the third passive piezoelectric resonator 123 changes with the target sensing quantity, so that the frequency difference between the first resonant frequency of the following resonant unit 12 and the second resonant frequency of the sensing resonant unit 13 is within the matching working range.

[0124] Embodiment four:

[0125] As shown in the following Figure 7 Resonant unit 12 includes fourth passive piezoelectric resonator 128 and first capacitance 122, and sensing resonant unit 13 includes second passive piezoelectric resonator 132 and capacitance sensing element 133.

[0126] The modulation element 11 is electrically connected to the first end of the fourth passive piezoelectric resonator 128 and the first end of the second passive piezoelectric resonator 132 respectively, and the second end of the fourth passive piezoelectric resonator 128 is electrically connected to the second end of the second passive piezoelectric resonator 132.

[0127] The first end of the capacitance sensing element 133 and the first end of the second passive piezoelectric resonator 132 are both electrically connected to the modulation element 11, and the second end is grounded;

[0128] The first terminal of the first capacitor 122 and the first terminal of the fourth passive piezoelectric resonator 128 are both electrically connected to the modulation element 11, and their second terminals are grounded.

[0129] The resonant frequency of the second passive piezoelectric resonator 132 does not change with environmental parameters, while the capacitance value of the capacitive sensing element 133 changes in response to the environmental sensing quantity, causing the second resonant frequency of the sensing resonant unit 13 to change with the target sensing quantity.

[0130] The resonant frequency of the fourth passive piezoelectric resonator 128 does not change with environmental parameters, and the capacitance value of the first capacitor 122 changes with the target sensing quantity, so that the frequency difference between the first resonant frequency of the following resonant unit 12 and the second resonant frequency of the sensing resonant unit 13 is within the matching working range.

[0131] Example 5

[0132] like Figure 8 As shown, in Scheme 2, the follower resonant unit 12 includes a first inductor 121 and a first capacitor 122 connected in series, and the sensing resonant unit 13 includes a second passive piezoelectric resonator 132 and a sensing element (such as a capacitive sensing element 133, an inductive sensing element 134, etc.).

[0133] The modulation element 11 is electrically connected to the first end of the second passive piezoelectric resonator 132 and the first end of the first inductor 121, respectively. The second end of the first inductor 121 is electrically connected to the first end of the first capacitor 122, and the second end of the first capacitor 122 is electrically connected to the second end of the second passive piezoelectric resonator 132.

[0134] The first end of the capacitive sensing element 133 is electrically connected to the second end of the second passive piezoelectric resonator 132 and the second end of the first capacitor 122. The first capacitor 122 changes with the target sensing quantity, so that the frequency difference between the first resonant frequency of the following resonant unit 12 and the second resonant frequency of the sensing resonant unit 13 is within the matching working range.

[0135] Preferably, the positions of the first inductor 121 and the first capacitor 122 can be interchanged. That is, the first end of the first capacitor 122 is electrically connected to the modulation element 11, the second end of the first capacitor 122 is electrically connected to the first end of the first inductor 121, and the second end of the first inductor 121 is electrically connected to the second end of the first passive piezoelectric resonator 131 and the first end of the capacitive sensing element 133, respectively.

[0136] More preferably, the first capacitor 122 has a fixed capacitance value, and the first inductor 121 can change with the target sensing quantity, so that the frequency difference between the first resonant frequency of the following resonant unit 12 and the second resonant frequency of the sensing resonant unit 13 is within the matching working range.

[0137] Example 6

[0138] like Figure 9 As shown, in Scheme 2, the follower resonant unit 12 includes a first inductor 121, a second capacitor 124 and a first capacitor 122, and the sensing resonant unit 13 includes a second inductor 135, a third capacitor 136 and an inductive sensing element 134.

[0139] The modulation element 11 is electrically connected to the first end of the second inductor 135 and the first end of the first inductor 121, respectively. The second end of the first inductor 121 is electrically connected to the first end of the second capacitor 124, and the second end of the second capacitor 124 is electrically connected to the second end of the third capacitor 136.

[0140] The first terminal of the inductive sensing element 134 and the first terminal of the second inductor 135 are both electrically connected to the modulation element 11, and their second terminals are grounded. The first terminal of the first capacitor 122 is electrically connected to the first terminal of the first inductor 121, and its second terminal is grounded. The first capacitor 122 changes with the target sensing quantity, so that the frequency difference between the first resonant frequency of the following resonant unit 12 and the second resonant frequency of the sensing resonant unit 13 is within the matching operating range.

[0141] Example 7

[0142] like Figure 10 As shown, the difference from Embodiment 6 is that the first capacitor 122 is omitted and the first inductor 121 is replaced by a third inductor 125. The third inductor 125 can change with the target sensing quantity, so that the frequency difference between the first resonant frequency of the following resonant unit 12 and the second resonant frequency of the sensing resonant unit 13 is within the matching working range.

[0143] By setting the first resonant frequency of the follower resonant unit 12 and the second resonant frequency of the sensing resonant unit 13 to change in the same direction as the target sensing quantity changes, the frequency difference between the first resonant frequency and the second resonant frequency can always be kept within the matching working range, thereby achieving the goal of extending the wireless working distance while maintaining sensing accuracy over a wide working frequency range.

[0144] The inductor in this invention can be 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 in this solution can be 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.

[0145] The present invention also provides a microwave direct-drive frequency converter terminal 100, such asFigure 11 As shown in the figure, the microwave direct-drive frequency conversion system comprises a microwave direct-drive frequency conversion circuit 10 and a first antenna 20 electrically connected to the microwave direct-drive frequency conversion circuit 10. The first antenna 20 is used for coupling to receive a first microwave signal with a first frequency from free space and coupling to output a frequency conversion signal with a second frequency from the microwave direct-drive frequency conversion circuit 10 to the free space.

[0146] The present application further provides a microwave direct-drive frequency conversion system, as shown in the figure, comprising a transceiver 200 and a plurality of microwave direct-drive frequency conversion terminals 100. The transceiver 200 is used for sending a first microwave signal with a first frequency (f1) to the microwave direct-drive frequency conversion terminals 100 and receiving a frequency conversion signal with a second frequency (f2) returned by the microwave direct-drive frequency conversion terminals 100 satisfying a communication rule. Figure 12

[0147] The present application further provides a microwave direct-drive frequency conversion sensing method based on the microwave direct-drive frequency conversion system, comprising the following steps:

[0148] S1, the transceiver 200 sends a first microwave signal with a first frequency;

[0149] S2, the microwave direct-drive frequency conversion terminal 100 receives the first microwave signal with the first frequency and returns a frequency conversion signal with a second frequency carrying sensing information to the transceiver 200;

[0150] S3, the transceiver 200 receives and analyzes the frequency conversion signal to obtain the sensing information.

[0151] The present application adopts a transceiver different frequency communication system, which can overcome the problems of short communication distance and serious same frequency interference existing in a transceiver same frequency communication system. By setting the first resonance frequency of the following resonance unit 12 and the second resonance frequency of the sensing resonance unit 13 to change in the same direction with the change of the target sensing quantity, the frequency difference between the first resonance frequency and the second resonance frequency can be kept within the matching working range at all times, so that the sensing precision can be maintained in a wide working frequency range while the wireless working distance is extended.

[0152] In the description of the present application, the description of the terms “one embodiment”, “some embodiments”, “an example”, “a specific example”, or “some examples” means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the description of the present application, the illustrative description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0153] ​While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely divergences of the principles and application of the present application and that numerous modifications, changes, substitutions, and alterations can be made thereto without departing from the spirit and scope of the present application, which is defined by the following claims and their equivalents.

Claims

1. A microwave direct-drive frequency conversion circuit, characterized by, The method comprises one of the following schemes: Scheme 1: The method comprises a modulation element, a following resonant unit and a sensing resonant unit, the modulation element is connected with the following resonant unit and the sensing resonant unit respectively; The modulation element is configured to receive a first microwave signal with a first frequency and output a frequency conversion signal with a second frequency; The following resonant unit is configured to have a first resonant frequency; The sensing resonant unit is configured to collect a target sensing quantity and has a second resonant frequency; The first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit change in the same direction with the change of the target sensing quantity, and the frequency difference between the first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit is always within a matching working range; Scheme 2: The method comprises a modulation element, a following resonant unit and a sensing resonant unit, the following resonant unit is connected with the modulation element, the sensing resonant unit is connected with the modulation element and the following resonant unit at the same time, and a microwave signal transmission path from the following resonant unit to the sensing resonant unit without passing through the modulation element is established; The modulation element is configured to receive a first microwave signal with a first frequency and output a frequency conversion signal with a second frequency; The following resonant unit is configured to have a first resonant frequency; The sensing resonant unit is configured to collect a target sensing quantity and has a second resonant frequency; The first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit change in the same direction with the change of the target sensing quantity, and the frequency difference between the first resonant frequency and the second resonant frequency is always within a matching working range.

2. The microwave direct drive frequency conversion circuit of claim 1, wherein, The size of the matching working range is positively correlated with the size of the first frequency.

3. The microwave direct drive frequency conversion circuit of claim 1, wherein, In scheme 1, The sensing resonant unit comprises a first piezoelectric resonator; The following resonant unit comprises a first inductor and a first capacitor; The sensing resonant unit responds to an environmental sensing quantity and outputs a microwave or radio frequency signal with a second resonant frequency which changes with the target sensing quantity; The first capacitor changes with the target sensing quantity, and the change of the first capacitor makes the change direction of the first resonant frequency of the following resonant unit the same as that of the second resonant frequency of the sensing resonant unit, so that the frequency difference between the first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit is within the matching working range.

4. The microwave direct drive frequency conversion circuit of claim 3, wherein, According to the resonance frequency variation of the sensing resonant unit and the following resonant unit in the first state and the second state, the capacitance value variation of the first capacitor in the following resonant unit is obtained and the resonance frequency variation of the sensing resonant unit, that is, wherein is the first resonance frequency of the following resonant unit in the first state, and C is the capacitance value of the first capacitor in the following resonant unit in the first state.​ And / or, according to the resonance frequency variation of the sensing resonant unit and the following resonant unit in the first state and the second state, the inductance value variation of the first inductor in the following resonant unit is obtained The relationship between the resonance frequency variation of the sensing resonant unit and the following resonant unit, that is, L, wherein The first resonance frequency of the following resonant unit in the first state, and L is the inductance value of the first inductor in the following resonant unit in the first state.​ 5. The microwave direct drive frequency conversion circuit of claim 1, wherein, In the first aspect, the following resonant unit includes a passive piezoelectric resonator, the resonant frequency of the passive piezoelectric resonator changes with the target sensing quantity, and the resonant frequency variation of the following resonant unit is equal to the resonant frequency variation of the sensing resonant unit. ​ 6. The microwave direct drive frequency conversion circuit of claim 1, wherein, In scheme 1, the sensing resonant unit comprises a resonator and a sensing element, and the resonator is connected with the sensing element; The resonant frequency of the resonator does not change with the environmental sensing quantity, and the sensing element changes in capacitance value in response to the environmental sensing quantity, so that the second resonant frequency of the sensing resonant unit changes with the target sensing quantity; The following resonant unit adopts a resonant network comprising a first inductor and a first capacitor, and the capacitance value of the first capacitor changes with the target sensing quantity, so that the frequency difference between the first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit is within the matching working range.

7. The microwave direct drive frequency conversion circuit of claim 1, wherein, In scheme 2, the following resonant unit comprises a third passive piezoelectric resonator, and the sensing resonant unit comprises a first passive piezoelectric resonator; The modulation element is connected with the first end of the third passive piezoelectric resonator and the first end of the first passive piezoelectric resonator respectively, and the second end of the third passive piezoelectric resonator is connected with the second end of the first passive piezoelectric resonator; The first passive piezoelectric resonator responds to the environmental sensing quantity and outputs a microwave or radio frequency signal of the second resonant frequency which changes with the target sensing quantity, and the third passive piezoelectric resonator changes with the target sensing quantity, so that the frequency difference between the first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit is within the matching working range.

8. The microwave direct drive frequency conversion circuit of claim 1, wherein, In the second scheme, the following resonant unit comprises a fourth passive piezoelectric resonator and a first capacitor, and the sensing resonant unit comprises a second passive piezoelectric resonator and a capacitive sensing element; The modulation element is connected with the first end of the fourth passive piezoelectric resonator and the first end of the second passive piezoelectric resonator respectively, and the second end of the fourth passive piezoelectric resonator is connected with the second end of the second passive piezoelectric resonator; The first end of the capacitive sensing element and the first end of the second passive piezoelectric resonator are connected with the modulation element, and the second end thereof is grounded; The first end of the first capacitor and the first end of the fourth passive piezoelectric resonator are connected with the modulation element, and the second end thereof is grounded; The resonant frequency of the second passive piezoelectric resonator does not change with the environmental parameter, and the capacitance value of the capacitive sensing element changes with the target sensing quantity, so that the second resonant frequency of the sensing resonant unit changes with the target sensing quantity; The capacitance value of the first capacitor changes with the target sensing quantity, so that the frequency difference between the first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit is within the matching working range.

9. The microwave direct drive frequency conversion circuit of claim 1, wherein, In the second scheme, the following resonant unit comprises a first inductor and a first capacitor in series, and the sensing resonant unit comprises a second passive piezoelectric resonator and a sensing element; The modulation element is connected with the first end of the second passive piezoelectric resonator and the first end of the first inductor respectively, the second end of the first inductor is connected with the first end of the first capacitor, and the second end of the first capacitor is connected with the second end of the second passive piezoelectric resonator; The first end of the sensing element is connected with the second end of the second passive piezoelectric resonator and the second end of the first capacitor, wherein the first capacitor changes with the target sensing quantity, so that the frequency difference between the first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit is within the matching working range.

10. The microwave direct drive frequency conversion circuit of claim 1, wherein, In the second scheme, the following resonant unit comprises a first inductor, a second capacitor and a first capacitor, and the sensing resonant unit comprises a second inductor, a third capacitor and an inductive sensing element; The modulation element is connected with the first end of the second inductor and the first end of the first inductor respectively, the second end of the first inductor is connected with the first end of the second capacitor, and the second end of the second capacitor is connected with the second end of the third capacitor; The first end of the inductive sensing element and the first end of the second inductor are connected with the modulation element, and the second end thereof is grounded; The first end of the first capacitor is connected with the first end of the first inductor, and the second end thereof is grounded, wherein the first capacitor changes with the target sensing quantity, so that the frequency difference between the first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit is within the matching working range.

11. The microwave direct drive frequency conversion circuit of claim 1, wherein, The modulation element comprises at least three modulation ports, a first modulation port for inputting a first microwave signal with a first frequency and outputting a frequency conversion signal with a second frequency; A following resonant unit is connected with the second modulation port, and a sensing resonant unit is connected with the third modulation port.

12. A microwave direct-drive frequency conversion terminal, characterized by The microwave direct-drive frequency conversion circuit comprises a first antenna connected with the microwave direct-drive frequency conversion circuit. The first antenna is used for coupling to receive a first microwave signal with a first frequency from free space and coupling to output a frequency conversion signal with a second frequency from the microwave direct-drive frequency conversion circuit to the free space.

13. A microwave direct-drive frequency converter system, characterized in that, The transceiver device is used for sending a first microwave signal with a first frequency to the microwave direct-drive frequency conversion terminal and receiving a frequency conversion signal with a second frequency returned by the microwave direct-drive frequency conversion terminal to meet a communication rule.

14. A microwave direct-drive frequency conversion sensing method based on the microwave direct-drive frequency conversion system of claim 13, characterized in that, The method comprises the following steps: S1, the transceiver device sends a first microwave signal with a first frequency; S2, the microwave direct-drive frequency conversion terminal receives the first microwave signal with the first frequency and returns a frequency conversion signal with a second frequency carrying sensing information to the transceiver device; S3, the transceiver device receives and analyzes the frequency conversion signal to obtain the sensing information.

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