Frequency conversion sensor and system

Abstract

The utility model discloses a frequency conversion sensor which comprises a modulation element, a first resonance circuit, a second resonance circuit and a sensing element. On the other hand, the utility model also provides a passive wireless frequency conversion sensing system. According to the utility model, energy convergence driving work is realized near the resonant frequency of the first resonant circuit through the fed microwave signal, and passive frequency conversion sensing of the sensing quantity to be measured can be realized without external power supply; the defects that in the prior art, a wireless sensor is high in power consumption, limited in application scene due to dependence on external power supply, high in use and maintenance cost and the like are fundamentally overcome, and the application scene of a wireless sensor network is greatly expanded.

Description

Technical Field

[0001] The utility model relates to the field of wireless communications, and more specifically, to a frequency conversion sensor and system. Background Art

[0002] Wireless sensor network is a comprehensive intelligent information system that integrates information collection, information transmission and information processing. Wireless sensor network is an important part of the Internet of Everything. It has a very broad application prospect. Its development and application will have a profound impact on all areas of human life and production. Wireless sensor network is an emerging frontier research hotspot with a high degree of multidisciplinary intersection. It can cooperate with each other through various integrated micro sensors to monitor, sense and collect information of various environments and monitoring objects in real time, and send the collected information to the end user through wireless communication after processing, truly realizing the interaction and integration of the physical environment, the information world and human society.

[0003] Wireless sensor networks have the characteristics of low cost, self-organization, small size and flexible deployment, so they have broad application prospects in military reconnaissance, environmental information detection, space exploration, agricultural production, medical health monitoring, construction and home, industrial production control, traffic control and business. However, to achieve large-scale application of wireless sensor networks, there is still a major problem in the node design of wireless sensor networks - high power consumption. Therefore, how to achieve ultra-low power consumption or even passive sensor nodes is a research hotspot in wireless sensor networks. Utility Model Content

[0004] The utility model overcomes the shortcomings of the prior art and provides a frequency conversion sensor and a system to realize a passive wireless sensor.

[0005] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0006] On one hand, the utility model provides a variable frequency sensor, comprising a modulation element, a first resonance circuit, a second resonance circuit and a sensing element.

[0007] The modulation element comprises a first port, a second port and a third port, and is used for mixing a first microwave signal fed through the microwave input and output port with an oscillation signal of a second resonant frequency fed through the second resonant circuit to generate a frequency conversion signal;

[0008] The first port is electrically connected to the microwave input and output ports;

[0009] The second port is electrically connected to the first resonant circuit;

[0010] The third port is electrically connected to the second resonant circuit;

[0011] The sensing element is used to convert the change of the sensor quantity to be measured into the change of capacitance or inductance;

[0012] The sensor element is disposed at at least one of: between the third port and the second resonance circuit, between the second port and the first resonance circuit, and between the first port and the microwave input and output port.

[0013] The working principle of the above frequency conversion sensor is: having a first frequency (f in ) is fed into the first port of the modulation element, and under the action of the first resonant circuit connected to the second port, the first frequency (f in ) The microwave signal realizes energy convergence near the resonant frequency of the first resonant circuit; the converged energy is fed into the second resonant circuit connected to the third port through the second port in the modulation element to generate a stable second resonant frequency (f res ) oscillating signal; the oscillating signal is fed into the modulation element via the third port, and is mixed with the first frequency (f in ) microwave signal mixing to generate a second frequency (f out ) of the frequency conversion signal, the frequency of the frequency conversion signal is f out f in ±n*f res , where n = 1, 2, 3 ..., thereby achieving the first frequency (f in )'s passive frequency conversion of microwave signals.

[0014] When the sensor quantity to be measured changes, the sensor element senses the change of the sensor quantity to be measured and converts the change of the sensor quantity to be measured into a change of capacitance or inductance. The change of the capacitance or inductance further causes the second resonant circuit to output a second resonant frequency (f res ), so that the frequency of the variable frequency signal f out It also changes with the sensor quantity to be measured, and passive frequency conversion sensing of the sensor quantity to be measured can be achieved according to the frequency change of the frequency conversion signal.

[0015] A further technical solution is that the sensor element is used to detect one or more of temperature, pressure, vibration, humidity, and dielectric constant.

[0016] A further technical solution is that the modulation element is a transistor with a heterojunction.

[0017] A further technical solution is that the modulation element is a heterojunction bipolar transistor or a field effect transistor.

[0018] A further technical solution is that the modulation element is a metal oxide semiconductor field effect transistor or a high electron mobility transistor.

[0019] A further technical solution is that the first port, the second port and the third port of the modulation element are any one of a drain, a source and a gate respectively.

[0020] A further technical solution is that the first resonant circuit and / or the second resonant circuit is a type of LC resonant circuit or RC resonant circuit.

[0021] A further technical solution is that the frequency conversion sensor further includes a matching circuit, and the matching circuit is connected to the first port;

[0022] The matching circuit is used to achieve impedance matching between the variable frequency sensor and the microwave input and output ports.

[0023] On the other hand, the utility model also provides a passive wireless frequency conversion sensing system.

[0024] A passive wireless frequency conversion sensor system comprises the frequency conversion sensor, a first antenna, a second antenna, and a transceiver as described above;

[0025] The transceiver is electrically connected to the first antenna, and the frequency conversion sensor is electrically connected to the second antenna;

[0026] The transceiver is used to send a signal to the first antenna, receive a returned frequency conversion signal, and demodulate corresponding information according to the frequency conversion signal;

[0027] The first antenna is used to send a first microwave signal to the second antenna and receive a frequency conversion signal returned by the second antenna;

[0028] The second antenna is used to receive the first microwave signal, send the signal to the frequency conversion sensor, and send the frequency conversion signal to the first antenna.

[0029] Compared with the prior art, the utility model has at least the following beneficial effects: the utility model realizes energy convergence driving operation near the resonant frequency of the first resonant circuit by feeding in microwave signals, and can realize passive frequency conversion perception of the sensor quantity to be measured without external power supply, fundamentally solving the disadvantages of high power consumption of wireless sensors in the prior art, limited application scenarios caused by dependence on external power supply, and high use and maintenance costs, greatly expanding the application scenarios of wireless sensor networks. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of the structure of a wireless communication circuit according to an embodiment of the present invention;

[0031] Figure 2 A schematic diagram of the structure of a wireless communication circuit according to an embodiment of the present invention;

[0032] Figure 3 A schematic diagram of the structure of a wireless communication circuit according to an embodiment of the present invention;

[0033] Figure 4 A schematic diagram of the structure of a wireless communication circuit according to an embodiment of the present invention;

[0034] Figure 5 A schematic diagram of the structure of a wireless communication circuit according to an embodiment of the present invention;

[0035] Figure 6 It is a schematic diagram of the structure of a wireless communication system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0037] In order to solve the technical problems of high power consumption and reliance on external power supply of existing wireless sensors, a variable frequency sensor is provided in one embodiment of the present invention. Figure 1 , including a modulation element, a first resonant circuit, a second resonant circuit and a sensing element.

[0038] The modulation element comprises a first port, a second port and a third port, and is used to mix a first microwave signal fed through the microwave input and output port with an oscillation signal of a second resonant frequency fed through the second resonant circuit to generate a frequency conversion signal;

[0039] The first frequency of the first microwave signal is f in , the second frequency of the frequency conversion signal is f out ;

[0040] The first port is electrically connected to the microwave input and output ports;

[0041] The second port is electrically connected to the first resonant circuit;

[0042] The third port is electrically connected to the second resonant circuit;

[0043] The sensor element is used to convert the change of the sensor quantity to be measured into the change of capacitance or inductance;

[0044] The sensor element is disposed at at least one of the following locations: between the third port and the second resonant circuit, between the second port and the first resonant circuit, and between the first port and the microwave input and output port.

[0045] The modulation element is fed with the first frequency f inThe first resonant circuit is used to disperse the energy of the first microwave signal, and to converge the microwave signal after the energy dispersion to obtain a second microwave signal, and feed the second microwave signal into the second resonant circuit.

[0046] In one embodiment of the present invention, the modulation element is a transistor with a heterojunction, including but not limited to a heterojunction bipolar transistor, a field effect transistor (FET), and a FET can be a metal oxide semiconductor field effect transistor (MOSFET), a two-dimensional electron gas transistor, or a high electron mobility transistor (HEMT).

[0047] In one embodiment of the present invention, the sensor element is disposed between the third port of the modulation element and the second resonance circuit, that is, one end of the sensor element is electrically connected to the second resonance circuit and the third port of the modulation element respectively.

[0048] When working, the sensor element senses the change of the sensor quantity to be measured, and converts the change of the sensor quantity to be measured into the change of capacitance or inductance. The change of capacitance or inductance further causes the second resonant circuit to output a second resonant frequency that changes with the change of capacitance or inductance, thereby completing the passive perception of the sensor quantity to be measured. The sensor quantity to be measured includes but is not limited to physical quantities such as temperature, pressure, vibration, humidity, and dielectric constant.

[0049] In one embodiment of the present invention, the first resonant circuit is one of an LC resonant circuit and an RC resonant circuit, and the second resonant circuit is one of an LC resonant circuit and an RC resonant circuit.

[0050] The main working process of the above frequency conversion sensor is as follows: having a first frequency (f in ) is fed into the first port of the modulation element. There is an electron migration channel in the modulation element. These electrons can form a signal transmission channel between the first port and the second port of the modulation element without DC bias, so that the first frequency (f in ) A microwave signal can be transmitted between the first port and the second port; and, under the action of a first resonant circuit connected to the second port, a first frequency (f in ) The microwave signal realizes energy convergence near the resonant frequency of the first resonant circuit; the converged energy is fed into the second resonant circuit connected to the third port through the second port in the modulation element to generate a stable second resonant frequency (f res ) oscillating signal; the oscillating signal is fed into the modulation element via the third port, and is mixed with the first frequency (f in ) microwave signal mixing to generate a second frequency (f out ) of the frequency conversion signal, the frequency of the frequency conversion signal is f out f in±n×f res , where n = 1, 2, 3 ..., thereby achieving the first frequency (f in )'s passive frequency conversion of microwave signals.

[0051] When the sensor quantity to be measured changes, the sensor element senses the change of the sensor quantity to be measured and converts the change of the sensor quantity to be measured into a change of capacitance or inductance. The change of the capacitance or inductance further causes the second resonant circuit to output a second resonant frequency (f res ), so that the frequency of the variable frequency signal f out It also changes with the sensor quantity to be measured, thereby realizing passive frequency conversion perception of the sensor quantity to be measured.

[0052] Figure 2 A variable frequency sensor according to an embodiment of the present invention is shown. Based on any of the aforementioned embodiments, the sensor element of this embodiment is arranged between the second port of the modulation element and the first resonant circuit, that is, one end of the sensor element is electrically connected to the first resonant circuit and the second port of the modulation element respectively, or one end of the sensor element is electrically connected to the second port of the modulation element, and the other end is electrically connected to the first resonant circuit.

[0053] Figure 3 A variable frequency sensor according to an embodiment of the present invention is shown. Based on any of the aforementioned embodiments, the sensor element of this embodiment is arranged between the first port of the modulation element and the microwave input / output port, that is, one end of the sensor element is electrically connected to the microwave input / output port and the first port of the modulation element respectively, or one end of the sensor element is electrically connected to the first port of the modulation element, and the other end is electrically connected to the microwave input / output port.

[0054] Figure 4 A variable frequency sensor according to an embodiment of the present invention is shown. Based on any of the above embodiments, the modulation element of this embodiment includes a metal oxide semiconductor field effect transistor (MOSFET), the sensor element includes an inductance sensor element, and the drain, source, and gate of the MOSFET serve as the first port, the second port, and the third port, respectively. One end of the inductance sensor element is connected to the gate of the MOSFET and the second resonant circuit, respectively.

[0055] Figure 5 A variable frequency sensor according to an embodiment of the present invention is shown. Based on any of the above embodiments, the modulation element of this embodiment includes a high electron mobility transistor (HEMT), the sensing element includes a capacitive sensing element, and the drain, source, and gate of the HEMT serve as the first port, the second port, and the third port, respectively. One end of the capacitive sensing element is connected to the source of the MOSFET and the first resonant circuit, respectively.

[0056] In this embodiment, when the first frequency (f in ) is fed into the drain of the HEMT. There is an electron migration channel in the HEMT. These electrons can form a signal transmission channel between the drain and the source without a DC bias, so that the first frequency (f in ) The microwave signal can be transmitted between the drain and the source; during the transmission process, the HEMT is fed with the first frequency (f in ) is used to disperse the energy of the microwave signal, and the microwave signal after energy dispersion is transmitted to the first resonant circuit, and energy convergence is realized near the resonant frequency of the first resonant circuit. The microwave signal after energy convergence is transmitted to the second resonant circuit and the inductance sensor element through the source and the gate. When the sensing quantity to be measured changes, the inductance sensor element senses the change of the sensing quantity to be measured, and converts the change of the sensing quantity to be measured into the change of inductance. The change of the above capacitance or inductance further causes the second resonant circuit to output a second resonant frequency (f res ), so that the frequency of the variable frequency signal f out It also changes with the sensor quantity to be measured, thereby realizing passive frequency conversion perception of the sensor quantity to be measured.

[0057] Figure 6 A passive wireless frequency conversion sensing system according to an embodiment of the present invention is shown, which comprises the wireless communication sensor, the first antenna, the second antenna, and the transceiver according to any of the above embodiments on the basis of any of the above embodiments;

[0058] The transceiver is electrically connected to the first antenna, and the frequency conversion sensor is electrically connected to the second antenna;

[0059] The transceiver is used to send a signal to the first antenna, receive a returned frequency conversion signal, and demodulate corresponding information according to the frequency conversion signal;

[0060] The first antenna is used to send the first microwave signal to the second antenna and receive the frequency conversion signal returned by the second antenna;

[0061] The second antenna is used to receive the first microwave signal, send the signal to the frequency conversion sensor, and send the frequency conversion signal to the first antenna.

[0062] When working, the transceiver sends a signal to the first antenna, and the first antenna sends a first microwave signal with a first frequency to the second antenna;

[0063] The second antenna receives the first microwave signal and sends the first microwave signal to the wireless communication sensor;

[0064] The modulation element of the wireless communication sensor mixes the first microwave signal fed in with the oscillation signal of the second resonant frequency fed in by the second resonant circuit, and sends the mixed frequency-converted signal to the second antenna;

[0065] The second antenna sends a frequency-converting signal;

[0066] The first antenna receives the returned frequency conversion signal and sends the frequency conversion signal to the transceiver;

[0067] The transceiver demodulates the corresponding information based on the frequency conversion signal.

[0068] Although the utility model is described herein with reference to the illustrative embodiments of the utility model, it should be understood that those skilled in the art can design many other modifications and implementations, which will fall within the scope and spirit of the principles disclosed in the present application. More specifically, within the scope disclosed in the present application, multiple variations and improvements can be made to the components and / or layout of the subject combination layout. In addition to the variations and improvements made to the components and / or layout, other uses will also be obvious to those skilled in the art.

Claims

1. A variable frequency sensor, characterized in that: It includes a modulation element, a first resonance circuit, a second resonance circuit and a sensing element; The modulation element comprises a first port, a second port and a third port, and is used to mix a first microwave signal fed through the microwave input and output port with an oscillation signal of a second resonant frequency fed through the second resonant circuit to generate a frequency conversion signal; The sensor element is used to convert the change of the sensor quantity to be measured into the change of capacitance or inductance; The sensor element is disposed at at least one of the following locations: between the third port and the second resonant circuit, between the second port and the first resonant circuit, and between the first port and the microwave input and output port.

2. A variable frequency sensor as claimed in claim 1, characterized in that: The sensing element is used to detect one or more of temperature, pressure, vibration, humidity, and dielectric constant.

3. A variable frequency sensor as claimed in claim 1, characterized in that: The modulation element is a transistor having a heterojunction.

4. A variable frequency sensor as claimed in claim 1 or 2, characterized in that: The modulation element is a heterojunction bipolar transistor or a field effect transistor.

5. A variable frequency sensor as claimed in claim 1, characterized in that: The modulation element is a metal oxide semiconductor field effect transistor or a high electron mobility transistor.

6. A variable frequency sensor as claimed in claim 4, characterized in that: The first port, the second port and the third port of the modulation element are any one of a drain, a source and a gate respectively.

7. A variable frequency sensor as claimed in claim 1 or 2, characterized in that: The first resonant circuit and / or the second resonant circuit is / are one of an LC resonant circuit and an RC resonant circuit.

8. A variable frequency sensor as claimed in claim 1 or 2, characterized in that: Also included is a matching circuit, wherein the matching circuit is electrically connected to the first port; The matching circuit is used to achieve impedance matching between the variable frequency sensor and the microwave input and output ports.

9. A variable frequency sensing system, characterized in that: It comprises the frequency conversion sensor, the first antenna, the second antenna, and the transceiver according to any one of claims 1 to 8; The transceiver is electrically connected to the first antenna, and the frequency conversion sensor is electrically connected to the second antenna; The transceiver is used to send a signal to the first antenna, receive a returned frequency conversion signal, and demodulate corresponding information according to the frequency conversion signal; The first antenna is used to send the first microwave signal to the second antenna and receive the frequency conversion signal returned by the second antenna; The second antenna is used to receive the first microwave signal, send the signal to the frequency conversion sensor, and send the frequency conversion signal to the first antenna.

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