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

Abstract

The invention belongs to the technical field of sensing systems of the Internet of Things, and particularly discloses a microwave direct-drive frequency conversion circuit, a terminal, a system and a method, the circuit comprises a scheme I that the circuit comprises a modulation element, a following resonance unit and a sensing resonance unit, and the modulation element is respectively connected with the following resonance unit and the sensing resonance unit; or according to the second scheme, the device comprises a modulation element, a following resonance unit and a sensing resonance unit, the following resonance unit is connected with the modulation element, the sensing resonance unit is connected with the modulation element and the following resonance unit at the same time, and a microwave signal transmission path from the following resonance unit to the sensing resonance unit without passing through the modulation element is established. By adopting the technical scheme, the first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit are set to be changed in the same direction along with the change of the target sensing quantity, so that the distance expansion is realized, and the sensing precision can be kept in a wide working frequency range.

Description

Technical Field

[0001] The present invention belongs to the technical field of Internet of Things sensor systems and relates to a microwave direct-drive frequency conversion circuit, a terminal, a system and a method. Background Art

[0002] At present, in the Internet of Things, sensor systems are often needed to collect, monitor and warn environmental data. According to the different transmission methods and technologies, the commonly used sensor systems in the Internet of Things can be divided into the following categories:

[0003] Wired sensing system: This type of sensing system uses wired connections to connect sensors to the network, and common interfaces include Ethernet, RS-485, USB, etc. Wired transmission systems have the advantages of stability, reliability, and strong anti-interference ability, but are limited by wiring and are not suitable for application scenarios that require high flexibility.

[0004] Wireless sensor systems: This type of sensor 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 and high flexibility, and are suitable for environments with wide distribution or difficult wiring. However, many wireless sensor systems still rely on batteries for power supply, which leads to battery life limitations and frequent battery replacement problems. For large-scale deployment of sensor networks, maintenance costs and operational complexity increase.

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

[0006] The common passive IoT sensing technologies such as RFID often have the same frequency for uplink and downlink carrier signals. This can easily lead to the gateway being unable to transmit high power due to frequency blocking, and the energy received by the tag is limited, which in turn leads to practical difficulties such as limited wireless communication distance. These difficulties are difficult to overcome. SAW sensors use analog signals, are susceptible to interference, rely on frequency differentiation, are prone to cross-reading, and have relatively low accuracy.

[0007] In addition, some existing passive wireless frequency conversion sensing technologies usually have two resonant networks, wherein the first resonant network is connected to the sensing element, and the second resonant network has a fixed resonant frequency. The resonant frequency difference between the first resonant network and the second resonant network usually has a matching working range. When the above resonant frequency difference exceeds the matching working range, the power or conversion efficiency of the returned frequency conversion signal will be greatly reduced, affecting the wireless sensing accuracy and distance. Summary of the invention

[0008] The object of the present invention is 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 object, the basic scheme of the present invention is: a microwave direct-drive frequency conversion circuit, including one of the following schemes:

[0010] Solution 1:

[0011] It includes a modulation element, a follower resonance unit and a sensing resonance unit, wherein the modulation element is connected to the follower resonance unit and the sensing resonance unit respectively;

[0012] The modulation element is configured to receive a first microwave signal having a first frequency and output a frequency-converted signal having a second frequency;

[0013] The follower resonance unit is configured to have a first resonance frequency;

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

[0015] The first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit both change in the same direction as the target sensing quantity changes, ensuring 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 a matching working range;

[0016] Option 2:

[0017] It includes a modulation element, a follower resonance unit and a sensing resonance unit, wherein the follower resonance unit is connected to the modulation element, and the sensing resonance unit is connected to both the modulation element and the follower resonance unit, so as to establish a microwave signal transmission path from the follower resonance unit to the sensing resonance unit without passing through the modulation element;

[0018] The modulation element is configured to receive a first microwave signal having a first frequency and output a frequency-converted signal having a second frequency;

[0019] The follower resonance unit is configured to have a first resonance frequency;

[0020] The sensing resonance unit is configured to collect a target sensing quantity and has a second resonance frequency;

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

[0022] The working principle and beneficial effects of this basic solution are as follows: this technical solution adopts a heterodyne frequency communication system, and 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 as the target sensing quantity changes, the frequency difference between the first resonant frequency and the second resonant frequency can be kept within the matching working range at all times, thereby achieving the goal of extending the wireless working distance while maintaining the sensing accuracy in 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 for ease of use.

[0025] Furthermore, in Plan 1,

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

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

[0028] The sensing resonance unit responds to the environmental sensing quantity and outputs a microwave or radio frequency signal of a second resonance frequency that changes with the target sensing quantity;

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

[0030] Simple structure and easy to operate.

[0031] Further, according to the change of the resonance frequency of the sensing resonance unit and the following resonance unit in the first state and the second state, the capacitance change ΔC of the first capacitor in the following resonance unit and the resonance frequency change Δf of the sensing resonance unit are obtained. Cr2 The relationship between where f r1 When in the first state, it follows the first resonant frequency of the resonant unit, and C is the capacitance value of the first capacitor in the resonant unit when in the first state;

[0032] And / or, according to the change of the resonance frequency of the sensing resonance unit and the following resonance unit in the first state and the second state, the change of the inductance value ΔL of the first inductor in the following resonance unit and the change of the resonance frequency Δf of the sensing resonance unit are obtained. Lr2 The relationship between where f r1 When L is in the first state, it follows the first resonant frequency of the resonant unit, and when L is in the first state, it follows the inductance value of the first inductor in the resonant unit.

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

[0034] Furthermore, in the first solution, the follower resonance unit includes a passive piezoelectric resonator, the resonance frequency of which changes with the target sensing value, and the resonance frequency change Δf of the follower resonance unit r1 The resonant frequency change Δf of the sensor resonant unit r2 equal.

[0035] The resonant frequency of the passive piezoelectric resonator changes with the target sensing quantity, ensuring that the frequency difference between the first resonant frequency and the second resonant frequency is within a matching working range.

[0036] Further, in the first solution, the sensor resonance unit includes a resonator and a sensor element, and the resonator is connected to the sensor element;

[0037] The resonant frequency of the resonator does not change with the environmental parameters, and the capacitance value of the sensing element changes in response to the environmental sensing value, so that the second resonant frequency of the sensor resonance unit changes with the target sensing value.

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

[0039] The capacitance value of the first capacitor may vary with the target sensing value, so that the frequency difference between the first resonance frequency of the follower resonance unit and the second resonance frequency of the sensing resonance unit is within a matching working range.

[0040] Further, in the second solution, the follower resonance unit includes a third passive piezoelectric resonator, and the sensor resonance unit includes a first passive piezoelectric resonator;

[0041] The modulation element is connected to 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 to 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 that changes with the target sensing quantity. The third passive piezoelectric resonator changes with the target sensing quantity, so that the frequency difference between the first resonant frequency of the follower resonance unit and the second resonant frequency of the sensing resonance unit is within a matching working range.

[0043] The components cooperate so that the frequency difference between the first resonance frequency of the follower resonance unit and the second resonance frequency of the sensor resonance unit is within a matching working range.

[0044] Further, in the second solution, the follower resonance unit includes a fourth passive piezoelectric resonator and a second capacitor, and the sensing resonance unit includes a first passive piezoelectric resonator and a capacitive sensing element;

[0045] The modulation element is connected to 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 to 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 both connected to the modulation element, and the second ends thereof are grounded;

[0047] The first end of the first capacitor and the first end of the fourth passive piezoelectric resonator are both connected to the modulation element, and the second ends thereof are grounded;

[0048] The resonant frequency of the second passive piezoelectric resonator does not change with environmental parameters, and the capacitance value of the capacitive sensing element changes in response to the environmental sensing value, so that the second resonant frequency of the sensor resonance unit changes with the target sensing value.

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

[0050] By using various devices, the frequency difference between the first resonance frequency of the follower resonance unit and the second resonance frequency of the sensor resonance unit is controlled to be within a matching working range.

[0051] Further, in the second solution, the follower resonance unit includes a first inductor and a first capacitor connected in series, and the sensing resonance unit includes a second passive piezoelectric resonator and a capacitive sensing element;

[0052] The modulation element is connected to 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 to the first end of the first capacitor, and the second end of the first capacitor is connected to the second end of the second passive piezoelectric resonator;

[0053] The first end of the capacitive sensing element is connected to 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 value, so that the frequency difference between the first resonant frequency of the follower resonance unit and the second resonant frequency of the sensing resonance unit is within a matching working range.

[0054] The first resonant frequency of the follower resonant unit and the second resonant frequency of the sensing resonant unit are set to change in the same direction as the target sensing quantity changes, ensuring 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 a matching working range.

[0055] Further, in the second solution, the follower resonance unit includes a first inductor, a second capacitor and a first capacitor, and the sensing resonance unit includes a second inductor, a third capacitor and an inductor-type sensing element;

[0056] The modulation element is connected to 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 to the first end of the second capacitor, and the second end of the second capacitor is connected to the second end of the third capacitor;

[0057] The first end of the inductor sensor element and the first end of the second inductor are both connected to the modulation element, and the second ends thereof are grounded;

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

[0059] By using various inductance and capacitance components, the frequency difference between the first resonance frequency of the follower resonance unit and the second resonance frequency of the sensor resonance unit is controlled to be within a 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 having a first frequency, and output a frequency conversion signal having a second frequency;

[0061] The follower resonance unit is connected to the second modulation port, and the sensor resonance unit is connected to the third modulation port.

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

[0063] The present invention further provides a microwave direct-drive frequency conversion terminal, comprising the microwave direct-drive frequency conversion circuit of the present invention, and a first antenna connected to the microwave direct-drive frequency conversion circuit;

[0064] The first antenna is used for coupling and receiving a first microwave signal with a first frequency from free space, and coupling and outputting a frequency conversion signal with a second frequency from a microwave direct-driven frequency conversion circuit into the free space.

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

[0066] The present invention also provides a microwave direct-drive frequency conversion system, comprising a transceiver and a plurality of microwave direct-drive frequency conversion terminals according to the present invention, wherein the transceiver is used to send a first frequency microwave signal to the microwave direct-drive frequency conversion terminal and receive a second frequency conversion signal returned by the microwave direct-drive frequency conversion terminal that meets the communication rules.

[0067] The system utilizes transceiver devices and terminals and adopts a different-frequency communication system, which can overcome the problems of short communication distance and severe same-frequency interference existing in the same-frequency communication system.

[0068] The present invention also provides a microwave direct-drive frequency conversion sensing method based on the microwave direct-drive frequency conversion system of the present invention, comprising the following steps:

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

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

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

[0072] The method sets the first resonant frequency of the follower resonant unit and the second resonant frequency of the sensor resonant unit to change in the same direction as the target sensing quantity changes, thereby always keeping the frequency difference between the first resonant frequency and the second resonant frequency within a matching working range. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 It is a structural schematic diagram of scheme 1 of embodiment 1 of the microwave direct-drive frequency conversion circuit of the present invention;

[0074] Figure 2 It is a resonant frequency variation curve diagram of the follower resonant unit and the sensor resonant unit under two states of the scheme 1 of the embodiment 1 of the microwave direct-driven frequency conversion circuit of the present invention;

[0075] Figure 3 It is a structural schematic diagram of scheme 2 of embodiment 1 of the microwave direct-drive frequency conversion circuit of the present invention;

[0076] Figure 4 It is a structural schematic diagram of a scheme 1 of embodiment 1 of a microwave direct-driven frequency conversion circuit of the present invention, in which a sensing resonance unit includes a first piezoelectric resonator, and a follower resonance unit includes a first inductor and a first capacitor;

[0077] Figure 5 It is a structural schematic diagram of scheme 1 of embodiment 2 of the microwave direct-drive frequency conversion circuit of the present invention;

[0078] Figure 6 It is a structural schematic diagram of scheme 2 of embodiment 3 of the microwave direct-drive frequency conversion circuit of the present invention;

[0079] Figure 7 It is a structural schematic diagram of scheme 2 of embodiment 4 of the microwave direct-drive frequency conversion circuit of the present invention;

[0080] Figure 8 It is a structural schematic diagram of scheme 2 of embodiment 5 of the microwave direct-drive frequency conversion circuit of the present invention;

[0081] Fig. 9 It is a structural schematic diagram of scheme 2 of embodiment 6 of the microwave direct-drive frequency conversion circuit of the present invention;

[0082] Fig.10 It is a structural schematic diagram of scheme 2 of embodiment 7 of the microwave direct-drive frequency conversion circuit of the present invention;

[0083] Fig.11 It is a schematic structural diagram of the microwave direct-driven frequency conversion terminal of the present invention;

[0084] Fig.12 It is a schematic structural diagram of the microwave direct-drive frequency conversion system of the present invention.

[0085] The reference numerals in the drawings of the specification include: microwave direct-driven frequency conversion circuit 10, modulation element 11, follower resonance unit 12, sensor resonance unit 13, first antenna 20;

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

[0087] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0088] In the description of the present invention, it is necessary to understand that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0089] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0090] The present invention discloses a microwave direct-drive frequency conversion circuit. Aiming at the practical problems existing in the prior art such as same-frequency blocking and limited communication distance, the present invention focuses on realizing a passive Internet of Things sensing technology that can extend the distance and maintain sensing accuracy in a wide operating frequency range.

[0091] Embodiment 1:

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

[0093] like Figure 1 As shown, option 1:

[0094] The modulation element 11 includes a modulation element 11, a follower resonance unit 12 and a sensor resonance unit 13. The modulation element 11 is electrically connected to the follower resonance unit 12 and the sensor resonance unit 13. The modulation element 11 is configured to receive a signal having a first frequency (f 1 ) and outputting a first microwave signal having a second frequency (f 2 ) frequency conversion signal.

[0095] The follower resonance unit 12 is configured to have a first resonance frequency (f r1 ), the sensing resonance unit 13 is configured to collect the 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 resonance unit 12 and the second resonant frequency of the sensing resonance unit 13 both change in the same direction as the target sensing quantity changes, ensuring that the frequency difference between the first resonant frequency of the following resonance unit 12 and the second resonant frequency of the sensing resonance unit 13 is always within the matching working range, thereby achieving the goal of extending the wireless working distance while maintaining the sensing accuracy in a wide working frequency range.

[0097] like Figure 2 As shown, the resonant frequency changes of the follower resonance unit 12 and the sensing resonance unit 13 in two states, wherein the left curve in state 1 is the resonance curve of the sensing resonance unit 13, and the right curve in state 1 is the resonance curve of the follower resonance unit 12; when the target sensing amount changes, the resonance curve of the sensing resonance unit 13 changes and transfers to the left curve in state 2. At this time, the frequency difference between the second resonance frequency of the sensing resonance unit 13 in state 2 and the first resonance frequency of the follower resonance unit 12 in state 1 has exceeded the matching working range. If the first resonance frequency of the follower resonance unit 12 is fixed, the conversion efficiency of the variable frequency signal in state 2 will deteriorate sharply, and even the variable frequency signal carrying the sensing information cannot be generated, thereby causing the sensing function to fail.

[0098] If the first resonant frequency of the follower resonant unit 12 also changes in the same direction as the second resonant frequency of the sensing resonant unit 13 as the target sensing quantity changes (for example, the resonance curve on the right side in state 2), it can be ensured 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 in state 2 is still 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 be referred to the prior patent application CN202411053036.6, wherein the second frequency (f 2 ) is a frequency conversion signal with a second resonant frequency (f r2 ) and a microwave signal having a first frequency (f 1 ) is mixed in the modulation element, that is, f 2 =f 1 ±n*f r2 , where n is a positive integer.

[0100] like Figure 3 As shown, option 2:

[0101] It includes a modulation element 11, a follower resonance unit 12 and a sensor resonance unit 13. The follower resonance unit 12 is electrically connected to the modulation element 11, and the sensor resonance unit 13 is electrically connected to the modulation element 11 and the follower resonance unit 12 at the same time. A microwave signal transmission path is established from the follower resonance unit 12 to the sensor resonance unit 13 without passing through the modulation element 11, so as to reduce the power loss of the microwave signal in the frequency conversion circuit, improve the power of the frequency conversion signal, and correspondingly reduce the microwave driving power threshold.

[0102] The modulation element 11 is configured to receive a first microwave signal having a first frequency and output a frequency conversion signal having a second frequency. The follower resonance unit 12 is configured to have a first resonance frequency, and the sensor resonance unit 13 is configured to collect a target sensing quantity and has a second resonance frequency.

[0103] The first resonant frequency of the follower resonant unit 12 and the second resonant frequency of the sensing resonant unit 13 both change in the same direction as the target sensing quantity changes, so that the frequency difference between the first resonant frequency and the second resonant frequency is always within the matching working range.

[0104] Preferably, the size of the matching working range is positively correlated with the size of the first frequency, such as when the first frequency is 13.56 MHz, the matching working range is no greater than 1 MHz; when the first frequency is 2.4 GHz, the matching working range is no greater than 20 MHz. The first microwave signal has any suitable first frequency microwave signal, the first frequency is an unlicensed frequency band open to industrial, scientific and medical institutions, or a conventional radio frequency identification frequency band, such as 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 comprises at least three modulation ports, the first modulation port being used to input a signal having a first frequency (f 1 ) and outputting a first microwave signal having a second frequency (f 2 ). The follower resonance unit 12 is electrically connected to the second modulation port, and the sensing resonance unit 13 is electrically connected to the 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 embodiment of the present invention, Figure 4As shown, in scheme one, the sensing resonance unit 13 includes a first piezoelectric resonator 131, and the resonance frequency of the first piezoelectric resonator 131 can change with the target sensing value. In other words, the first piezoelectric resonator 131 serves as both a sensing element and a frequency selection element; the follower resonance unit 12 adopts an LC resonance network, and the follower resonance unit 12 includes a first inductor 121 and a first capacitor 122. The sensing resonance unit 13 responds to the environmental sensing value and outputs a microwave or radio frequency signal of a second resonance frequency that changes with the target sensing value.

[0107] The first capacitor 122 (for example, Figure 4 The variable capacitance in the sensor changes with the target sensing value, and the change of the first capacitor 122 makes the change direction of the first resonant frequency of the follower resonance unit 12 and the change direction of the second resonant frequency of the sensing resonance unit 13 the same, so that the frequency difference between the first resonant frequency of the follower resonance unit 12 and the second resonant frequency of the sensing resonance unit 13 is within the matching working range.

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

[0109] Preferably, according to the resonant frequency changes of the sensing resonant unit 13 (the 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 capacitance change ΔC of the first capacitor 122 in the follower resonant unit 12 and the resonant frequency change Δf of the sensing resonant unit 13 can be obtained. Cr2 The relationship between where f r1 When in the first state, it follows the first resonant frequency of the resonant unit 12, and when C is in the first state, it follows the capacitance value of the first capacitor 122 in the resonant unit 12;

[0110] And / or, according to the change of the resonance frequency of the sensing resonance unit 13 and the following resonance unit 12 in the first state and the second state, the change ΔL of the inductance value of the first inductor 121 in the following resonance unit 12 and the change Δf of the resonance frequency of the sensing resonance unit 13 are obtained. Lr2 The relationship between where f r1 When L is in the first state, it follows the first resonant frequency of the resonant unit 12 . When L is in the first state, it follows the inductance value of the first inductor 121 in the resonant unit 12 .

[0111] More preferably, the passive piezoelectric resonator can be any passive resonator that works 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 1, the follower resonance unit 12 includes a passive piezoelectric resonator, the resonance frequency of the passive piezoelectric resonator changes with the target sensing quantity, and the resonance frequency change Δf_r1 of the follower resonance unit 12 is equal to the resonance frequency change Δf_r2 of the sensing resonance unit 13.

[0113] Embodiment 2:

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

[0116] Alternatively, a current sensor or a voltage sensor is used, and the first end of the current sensor or the voltage sensor and the second passive piezoelectric resonator 132 is electrically connected to the modulation element 11, and the second end of the second passive piezoelectric resonator 132 is grounded. Alternatively, the first end of the current sensor or the voltage sensor and the series LC resonant network is electrically connected to the modulation element 11, and the second end of the series LC resonant network is grounded; or the first end of the current sensor or the voltage sensor and the parallel LC resonant network is electrically connected to the modulation element 11, and the second end of the parallel LC resonant network is grounded.

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

[0118] The follower resonance unit 12 adopts an LC resonance network, including a first inductor 121 and a first capacitor 122, wherein the capacitance value of the first capacitor 122 changes with the target sensing value, so that the frequency difference between the first resonance frequency of the follower resonance unit 12 and the second resonance frequency of the sensing resonance unit 13 is within the matching working range.

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

[0120] Embodiment three:

[0121] like Figure 6 As shown, in the second solution, the follower resonance unit 12 includes a third passive piezoelectric resonator 123 , and the sensor resonance unit 13 includes a first passive piezoelectric resonator 131 .

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

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

[0124] Embodiment 4:

[0125] like Figure 7 As shown, in the second solution, the follower resonance unit 12 includes a fourth passive piezoelectric resonator 128 and a first capacitor 122 , and the sensor resonance unit 13 includes a second passive piezoelectric resonator 132 and a capacitive sensor element 133 .

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

[0127] The first end of the capacitive 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 ends thereof are grounded;

[0128] The first end of the first capacitor 122 and the first end of the fourth passive piezoelectric resonator 128 are both electrically connected to the modulation element 11, and the second ends thereof are grounded;

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

[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 value, so that the frequency difference between the first resonant frequency of the follower resonance unit 12 and the second resonant frequency of the sensing resonance unit 13 is within the matching working range.

[0131] Embodiment 5

[0132] like Figure 8 As shown, in scheme 2, the follower resonance unit 12 includes a first inductor 121 and a first capacitor 122 connected in series, and the sensor resonance unit 13 includes a second passive piezoelectric resonator 132 and a sensor element (such as a capacitive sensor element 133, an inductive sensor 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, wherein the first capacitor 122 changes with the target sensing value, so that the frequency difference between the first resonant frequency of the follower resonance unit 12 and the second resonant frequency of the sensing resonance unit 13 is within the matching working range.

[0135] Preferably, the positions of the first inductor 121 and the first capacitor 122 can be swapped, 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 value, so that the frequency difference between the first resonance frequency of the follower resonance unit 12 and the second resonance frequency of the sensing resonance unit 13 is within the matching working range.

[0137] Embodiment 6

[0138] like Fig. 9 As shown, in the second solution, the follower resonance unit 12 includes a first inductor 121 , a second capacitor 124 and a first capacitor 122 , and the sensor resonance unit 13 includes a second inductor 135 , a third capacitor 136 and an inductor-type sensor 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 . The second end of the second capacitor 124 is electrically connected to the second end of the third capacitor 136 .

[0140] The first end of the inductor sensor element 134 and the first end of the second inductor 135 are both electrically connected to the modulation element 11, and the second ends thereof are grounded. The first end of the first capacitor 122 is electrically connected to the first end of the first inductor 121, and the second end thereof is grounded, wherein the first capacitor 122 changes with the target sensing value, so that the frequency difference between the first resonant frequency of the follower resonance unit 12 and the second resonant frequency of the sensing resonance unit 13 is within the matching working range.

[0141] Embodiment 7

[0142] like Fig.10 As shown, the difference from Example 6 is that the first capacitor 122 is omitted, and the third inductor 125 is used to replace the first inductor 121, wherein the third inductor 125 can change with the target sensing value, so that the frequency difference between the first resonant frequency of the follower resonance unit 12 and the second resonant frequency of the sensing resonance 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 be kept within the matching working range at all times, thereby achieving the goal of extending the wireless working distance while maintaining the sensing accuracy in a wide working frequency range.

[0144] The inductor in the present invention may be a single real inductor element or an equivalent inductor element, such as an equivalent inductor element obtained by connecting two independent real inductors in series, or an equivalent inductor element obtained by other circuit forms. Similarly, the capacitor in the present solution may 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 forms.

[0145] The present invention also provides a microwave direct-drive frequency conversion terminal 100, such as Fig.11 As shown, it includes the microwave direct-driven frequency conversion circuit 10 of the present invention, and a first antenna 20 electrically connected to the microwave direct-driven frequency conversion circuit 10. The first antenna 20 is used to couple and receive a first microwave signal with a first frequency from free space, and couple and output a frequency conversion signal with a second frequency from the microwave direct-driven frequency conversion circuit 10 into the free space.

[0146] The present invention also provides a microwave direct drive frequency conversion system, such as Fig.12 As shown, it includes a transceiver 200 and a plurality of microwave direct-driven frequency conversion terminals 100 according to the present invention, and the transceiver 200 is used to send a first frequency (f 1 ) microwave signal, and receives the second frequency (f 2 ) frequency conversion signal.

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

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

[0149] S2, the microwave direct-driven frequency conversion terminal 100 receives a first microwave signal with a 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 sensing information.

[0151] The present invention adopts a transmission and reception different frequency communication system, which can overcome the problems of short communication distance and serious co-frequency interference existing in the transmission and reception same frequency communication system. By setting the first resonant frequency of the follower resonance unit 12 and the second resonant frequency of the sensing resonance 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 be kept within the matching working range at all times, thereby achieving the goal of extending the wireless working distance while maintaining the sensing accuracy in a wide working frequency range.

[0152] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0153] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A microwave direct-drive frequency conversion circuit, characterized in that: This includes one of the following options: Option 1: It includes a modulation element, a follower resonance unit and a sensing resonance unit, wherein the modulation element is connected to the follower resonance unit and the sensing resonance unit respectively; The modulation element is configured to receive a first microwave signal having a first frequency and output a frequency-converted signal having a second frequency; The follower resonance unit is configured to have a first resonance frequency; The sensing resonance unit is configured to collect a target sensing quantity and has a second resonance frequency; The first resonant frequency of the following resonant unit and the second resonant frequency of the sensing resonant unit both change in the same direction as the target sensing quantity changes, ensuring 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 a matching working range; Option 2: It includes a modulation element, a follower resonance unit and a sensing resonance unit, wherein the follower resonance unit is connected to the modulation element, and the sensing resonance unit is connected to both the modulation element and the follower resonance unit, so as to establish a microwave signal transmission path from the follower resonance unit to the sensing resonance unit without passing through the modulation element; The modulation element is configured to receive a first microwave signal having a first frequency and output a frequency-converted signal having a second frequency; The follower resonance unit is configured to have a first resonance frequency; The sensing resonance unit is configured to collect a target sensing quantity and has a second resonance frequency; The first resonant frequency of the follower resonant unit and the second resonant frequency of the sensing resonant unit both change in the same direction as the target sensing quantity changes, so that the frequency difference between the first resonant frequency and the second resonant frequency is always kept within the matching working range.

2. The microwave direct-drive frequency conversion circuit according to claim 1, characterized in that: 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 according to claim 1, characterized in that: In plan one, The sensing resonance unit includes a first piezoelectric resonator; The follower resonance unit includes a first inductor and a first capacitor; The sensing resonance unit responds to the environmental sensing quantity and outputs a microwave or radio frequency signal of a second resonance frequency that changes with the target sensing quantity; The first capacitance changes with the target sensing value, and the change of the first capacitance makes the change direction of the first resonance frequency of the follower resonance unit the same as the change direction of the second resonance frequency of the sensing resonance unit, so that the frequency difference between the first resonance frequency of the follower resonance unit and the second resonance frequency of the sensing resonance unit is within the matching working range.

4. The microwave direct-drive frequency conversion circuit according to claim 3, characterized in that: According to the resonant frequency changes of the sensing resonant unit and the following resonant unit in the first state and the second state, the capacitance change ΔC of the first capacitor in the following resonant unit and the resonant frequency change Δf of the sensing resonant unit are obtained. Cr2 The relationship between where f r1 When in the first state, it follows the first resonant frequency of the resonant unit, and C is the capacitance value of the first capacitor in the resonant unit when in the first state; And / or, according to the change of the resonance frequency of the sensing resonance unit and the following resonance unit in the first state and the second state, the change of the inductance value ΔL of the first inductor in the following resonance unit and the change of the resonance frequency Δf of the sensing resonance unit are obtained. Lr2 The relationship between where f r1 When L is in the first state, it follows the first resonant frequency of the resonant unit, and when L is in the first state, it follows the inductance value of the first inductor in the resonant unit.

5. The microwave direct-drive frequency conversion circuit according to claim 1, characterized in that: In the first scheme, the follower resonance unit includes a passive piezoelectric resonator, the resonance frequency of which changes with the target sensing value, and the resonance frequency change of the follower resonance unit is Δf r1 The resonant frequency change Δf of the sensor resonant unit r2 equal.

6. The microwave direct-drive frequency conversion circuit according to claim 1, characterized in that: In the first solution, the sensor resonance unit includes a resonator and a sensor element, and the resonator is connected to the sensor element; The resonant frequency of the resonator does not change with the environmental parameters, and the capacitance value of the sensing element changes in response to the environmental sensing value, so that the second resonant frequency of the sensor resonance unit changes with the target sensing value. The follower resonance unit adopts a resonance network, including a first inductor and a first capacitor, wherein the capacitance value of the first capacitor changes with the target sensing value, so that the frequency difference between the first resonance frequency of the follower resonance unit and the second resonance frequency of the sensing resonance unit is within a matching working range.

7. The microwave direct-drive frequency conversion circuit according to claim 1, characterized in that: In the second solution, the follower resonance unit includes a third passive piezoelectric resonator, and the sensor resonance unit includes a first passive piezoelectric resonator; The modulation element is connected to 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 to 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 a second resonant frequency that changes with the target sensing quantity. The third passive piezoelectric resonator changes with the target sensing quantity, so that the frequency difference between the first resonant frequency of the follower resonance unit and the second resonant frequency of the sensing resonance unit is within a matching working range.

8. The microwave direct-drive frequency conversion circuit according to claim 1, characterized in that: In the second solution, the follower resonance unit includes a fourth passive piezoelectric resonator and a first capacitor, and the sensing resonance unit includes a second passive piezoelectric resonator and a capacitive sensing element; The modulation element is connected to 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 to 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 both connected to the modulation element, and the second ends thereof are grounded; The first end of the first capacitor and the first end of the fourth passive piezoelectric resonator are both connected to the modulation element, and the second ends thereof are grounded; The resonant frequency of the second passive piezoelectric resonator does not change with environmental parameters, and the capacitance value of the capacitive sensing element changes in response to the environmental sensing value, so that the second resonant frequency of the sensor resonance unit changes with the target sensing value. The capacitance value of the first capacitor changes with the target sensing value, so that the frequency difference between the first resonance frequency of the follower resonance unit and the second resonance frequency of the sensing resonance unit is within a matching working range.

9. The microwave direct-drive frequency conversion circuit according to claim 1, characterized in that: In the second solution, the follower resonance unit includes a first inductor and a first capacitor connected in series, and the sensor resonance unit includes a second passive piezoelectric resonator and a sensor element; The modulation element is connected to 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 to the first end of the first capacitor, and the second end of the first capacitor is connected to the second end of the second passive piezoelectric resonator; The first end of the sensing element is connected to 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 value, so that the frequency difference between the first resonant frequency of the follower resonance unit and the second resonant frequency of the sensing resonance unit is within a matching working range.

10. The microwave direct-drive frequency conversion circuit according to claim 1, characterized in that: In the second solution, the follower resonance unit includes a first inductor, a second capacitor and a first capacitor, and the sensing resonance unit includes a second inductor, a third capacitor and an inductor-type sensing element; The modulation element is connected to 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 to the first end of the second capacitor, and the second end of the second capacitor is connected to the second end of the third capacitor; The first end of the inductor sensor element and the first end of the second inductor are both connected to the modulation element, and the second ends thereof are grounded; The first end of the first capacitor is connected to the first end of the first inductor, and the second end thereof is grounded, wherein the first capacitor changes with the target sensing value, so that the frequency difference between the first resonant frequency of the follower resonance unit and the second resonant frequency of the sensing resonance unit is within a matching working range.

11. The microwave direct-drive frequency conversion circuit according to claim 1, characterized in that: The modulation element comprises at least three modulation ports, wherein the first modulation port is used to input a first microwave signal having a first frequency and output a frequency conversion signal having a second frequency; The follower resonance unit is connected to the second modulation port, and the sensor resonance unit is connected to the third modulation port.

12. A microwave direct-drive frequency conversion terminal, characterized in that: The method comprises the microwave direct-driven frequency conversion circuit according to any one of claims 1 to 11, and a first antenna connected to the microwave direct-driven frequency conversion circuit; The first antenna is used for coupling and receiving a first microwave signal with a first frequency from free space, and coupling and outputting a frequency conversion signal with a second frequency from a microwave direct-driven frequency conversion circuit into the free space.

13. A microwave direct drive frequency conversion system, characterized in that: It comprises a transceiver and several microwave direct-driven frequency conversion terminals as described in claim 12, wherein the transceiver is used to send a first frequency microwave signal to the microwave direct-driven frequency conversion terminal and receive a second frequency conversion signal returned by the microwave direct-driven frequency conversion terminal that meets the communication rules.

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

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