Frequency shift keying passive wireless sensor, system and control method

Abstract

The present invention discloses a frequency shift keying passive wireless sensor, system and control method. The present invention uses a dedicated integrated circuit to match digital baseband signals with the resonant frequencies of different microwave frequency conversion devices. The microwave frequency conversion devices of the MDFC unit are controlled to connect different frequency selection devices through an analog switch array to achieve frequency shift keying modulation of the driven return signal of the MDFC unit, so that the frequency shift keying passive wireless sensor can transmit the baseband signal, and the information receiver can identify the baseband signal by decoding the modulated information. The problems of probe capacity and information coding existing in the existing MDFC sensor are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of passive wireless sensing, and more specifically, to a frequency shift keying passive wireless sensor, system and control method. Background Art

[0002] A passive wireless sensor based on Microwave Driven Frequency Conversion (MDFC) technology is a sensor that uses a passive crystal oscillator inside the sensor end or a variable capacitor or variable inductor externally connected to the passive crystal oscillator as a sensing element to convert the sensor quantity to be measured into a change in capacitance or inductance, complete the modulation of the received microwave signal, and complete the passive perception of different types of sensor quantities.

[0003] The working principle of the existing MDFC sensor is that the transceiver transmits a driving signal, and when the driving power is met, the MDFC sensor generates a response signal of different frequency, and the transceiver receives the response signal and calculates the sensing quantity. However, due to the limited types of frequency selection devices and analog communication methods, the system has defects in probe capacity, information coding, information transmission reliability, etc.

[0004] Specifically, in terms of the number of probes, when the system is working, the transceiver sends out a microwave driving signal with a frequency of f0, and the passive wireless sensor generates a frequency of f when receiving the driving signal of f0. rn The driven return signal is the sensor quantity, and the driven return signal is affected by the sensor quantity. The working bandwidth of each probe is a range, which is recorded as f tag , when the receiving bandwidth of the transceiver is f total After determination, the number of sensors N that a transceiver can accept for identification is also limited, N = f total / f tag . Summary of the invention

[0005] The present invention overcomes the deficiencies of the prior art and provides a frequency shift keying passive wireless sensor, system and control method, in the hope of solving the problems of probe capacity, information coding and the like existing in the prior art.

[0006] In order to solve the above technical problems, the present invention provides a frequency shift keying MDFC sensor.

[0007] A frequency shift keying passive wireless sensor, comprising an energy collection unit, a dedicated integrated circuit, a switch matrix unit, a frequency selection device, and an MDFC unit;

[0008] For the working principle of the MDFC unit, please refer to the prior application, "A passive frequency conversion structure and passive frequency conversion method" (application number 202310112908.0).

[0009] The MDFC unit is connected to the switch matrix unit, and the MDFC unit includes a microwave frequency conversion device, and the microwave frequency conversion device is used to achieve mixing of the fed microwave signal and the oscillation signal in the transistor, thereby achieving passive frequency conversion;

[0010] The energy collection unit is connected to a dedicated integrated circuit, and the dedicated integrated circuit is connected to a switch matrix unit;

[0011] The common end of the switch matrix unit is connected to a microwave frequency conversion device, and the port of the switch matrix unit is connected to a frequency selection device, and the number of the frequency selection devices is 2 or more.

[0012] The energy collection unit supplies power to the ASIC, which matches the digital baseband signal (including but not limited to ID information, sensor value, etc.) with the resonant frequency of different frequency selection devices. The microwave frequency conversion device of the MDFC unit is controlled by the analog switch array to connect different frequency selection devices to change the frequency conversion frequency f of the MDFC. c , and then realize frequency shift keying modulation of the driven return signal of the MDFC unit, so as to transmit other information including ID information, so that the information receiver can identify the ID information of the MDFC unit source of the information by decoding the modulated information.

[0013] A further technical solution is that the MDFC unit further includes an antenna, an input matching network, and a resonant network;

[0014] The antenna is connected to an input matching network, and the input matching network and the resonant network are connected to a microwave frequency conversion device;

[0015] The microwave frequency conversion device is connected to the common end of the switch matrix unit.

[0016] A further technical solution is that the energy collection unit includes one or both of a microwave energy conversion unit and a photovoltaic energy conversion unit.

[0017] The type of energy harvesting unit can be selected based on the installation location of the passive wireless sensor.

[0018] A further technical solution is that the microwave energy conversion unit includes a microwave antenna, an energy collection unit, and a power management unit;

[0019] The microwave antenna is connected to an energy collection unit, and the energy collection unit is connected to a power management unit.

[0020] The microwave antenna can collect the driving signal, and the energy collection unit collects the driving signal and converts it into direct current energy, which is then distributed by the power management unit and provided to the dedicated integrated circuit.

[0021] A further technical solution is that the dedicated integrated circuit is a low-power MCU.

[0022] The present invention also provides a frequency shift keying passive wireless sensor system, comprising the frequency shift keying passive wireless sensor and a transceiver as described above;

[0023] The transceiver includes a transceiver module, a signal processing unit, and a power management unit, wherein the power management unit is connected to the transceiver module and the signal processing unit, and the transceiver module is connected to the signal processing unit;

[0024] The transceiver module is used to transmit microwave driving signals, receive driven return signals, and send them to the signal processing unit;

[0025] The signal processing unit is used to process the driven return signal and calculate the baseband signal and the sensor test result.

[0026] The present invention also provides a frequency shift keying passive wireless sensor control method, comprising the following steps:

[0027] The transceiver transmits a microwave drive signal;

[0028] The energy harvesting unit supplies power to the ASIC;

[0029] The ASIC in the sensor encodes the baseband information;

[0030] The dedicated integrated circuit drives the analog switch matrix to connect the microwave frequency conversion device to different frequency selection devices, so that the microwave frequency conversion device generates driven return signals of different frequencies, thereby realizing frequency shift keying modulation of the driven return signals;

[0031] The transceiver receives and analyzes the modulated driven return signal and calculates the baseband signal.

[0032] Compared with the prior art, the present invention has at least the following beneficial effects: the present invention uses a dedicated integrated circuit to correspond the digital baseband signal to the resonant frequency of different microwave frequency conversion devices. The microwave frequency conversion devices of the MDFC unit are controlled to connect to different frequency selection devices through an analog switch array to achieve frequency shift keying modulation of the driven return signal of the MDFC unit, thereby transmitting other information including ID information, so that the information receiver can identify the information by decoding the modulated information, thereby solving the problems of probe capacity and information coding in the existing MDFC sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the structure of a frequency shift keying passive wireless sensor in Example 1;

[0034] Figure 2 It is a schematic diagram of the driving signal and the driven return signal of the MDFC unit;

[0035] Figure 3 Schematic diagram of the steps of Example 3. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0037] Embodiment 1

[0038] A frequency shift keying passive wireless sensor, see Figure 1 , including , an energy harvesting unit, a ASIC, a switch matrix unit, a frequency selection device, and a MDFC unit;

[0039] The MDFC unit is connected to the switch matrix unit, and the MDFC unit includes a microwave frequency conversion device, an antenna, an input matching network, and a resonance network.

[0040] The microwave frequency conversion device is used to achieve mixing of the fed microwave signal and the oscillation signal in the transistor, thereby achieving passive frequency conversion;

[0041] The antenna is connected to an input matching network, and the input matching network and the resonant network are connected to a microwave frequency conversion device;

[0042] The microwave frequency conversion device is connected to the common end of the switch matrix unit.

[0043] The energy collection unit is connected to a dedicated integrated circuit, and the dedicated integrated circuit is connected to a switch matrix unit; in this embodiment, the dedicated integrated circuit is a low-power MCU.

[0044] The energy collection unit includes one or both of a microwave energy conversion unit and a photovoltaic energy conversion unit. In this embodiment, the energy collection unit is a microwave energy conversion unit.

[0045] The microwave energy conversion unit includes a microwave antenna, an energy collection unit, and a power management unit;

[0046] The microwave antenna is connected to an energy collection unit, and the energy collection unit is connected to a power management unit.

[0047] The common end of the switch matrix unit is connected to a microwave frequency conversion device, and the port of the switch matrix unit is connected to a frequency selection device, and the number of the frequency selection devices is 2 or more;

[0048] The microwave frequency conversion device is used to receive a driving signal and generate a response signal of a different frequency according to a sensing quantity.

[0049] When the energy collection unit, dedicated integrated circuit, switch matrix unit, and frequency selection device are not installed, the working principle of the MDFC unit is as follows: the transceiver sends a microwave driving signal with a frequency of f0, and the passive wireless sensor generates a frequency of f when receiving the driving signal of f0. rn The driven return signal (frequency f rn =f0±n·f c , where n = 1, 2, 3, ..., f c The device frequency is selected for the frequency), the driving signal and the driven return signal are as follows Figure 2 shown.

[0050] The signal modulation principle of the frequency shift keying passive wireless sensor of this embodiment is that the dedicated integrated circuit drives the analog switch matrix, so that the microwave frequency conversion device is connected to different frequency selection devices, so that the microwave frequency conversion device generates driven return signals with different frequencies frn, and realizes frequency shift keying modulation of the driven return signal;

[0051] In this embodiment, the switch matrix unit is connected to four frequency selection devices, the signal transmission system uses 4FSK, and a 4-port analog switch array can be used.

[0052] When the code element is 00, the low-power MCU turns on the analog switch port A through the output level. At this time, the MDFC microwave frequency conversion device uses the resonant frequency f of the frequency selection device A. c1 , then the frequency of the driven return signal is f r1 =f0±n·f c1 (where n = 1, 2, 3, ..., f c1 is the resonant frequency of the frequency-selective device A).

[0053] Similarly, code element 01 is realized by turning on port B, and the driven return signal frequency f r2 =f0±n·f c2 ;

[0054] Code element 10 is realized by turning on port C, and the driven return signal frequency f r3 =f0±n·f c3 ;

[0055] Code element 11 is realized by turning on port D, and the driven return signal frequency f r4 =f0±n·f c4 ;

[0056] f c1 、f c2 、f c3 are the resonant frequencies of frequency selective devices B, C, and D respectively.

[0057] The modulated 4FSK signal can judge the received code elements through different receiving frequencies, restore the baseband signal, and realize the passive wireless transmission 4FSK signal system.

[0058] In specific use, two microwave frequency conversion devices are set, different ID information is set for the two microwave frequency conversion devices, and the ID information is input into the low-power MCU as a baseband signal;

[0059] The MDFC unit receives the microwave driving signal with frequency f0 from the transceiver, and the passive wireless sensor generates a frequency f rn The driven return signal;

[0060] The low-power MCU controls the switch matrix unit to modulate the driven return signal f rn , perform 4FSK modulation on the driven return signal according to the baseband signal, and send out the modulated signal;

[0061] The transceiver receives the modulated signal, judges the received code element through different receiving frequencies, and recovers the baseband signal and the driven return signal f rn , by making the driven return signal f rn By calculating and restoring the sensor value and corresponding it to the baseband signal of the ID information, the sensor values ​​measured by different microwave frequency conversion devices can be identified, thereby increasing the number of sensors that the transceiver can accept and identify.

[0062] Embodiment 2

[0063] A frequency shift keying passive wireless sensor system, characterized by comprising the frequency shift keying passive wireless sensor and a transceiver as described above;

[0064] The transceiver includes a transceiver module, a signal processing unit, and a power management unit, wherein the power management unit is connected to the transceiver module and the signal processing unit, and the transceiver module is connected to the signal processing unit;

[0065] The transceiver module is used to transmit microwave driving signals, receive driven return signals, and send them to the signal processing unit;

[0066] The signal processing unit is used to process the driven return signal and calculate the baseband signal and the sensor test result.

[0067] Embodiment 3

[0068] A frequency shift keying passive wireless sensor control method, see Figure 3 , including the following steps:

[0069] S1: The transceiver transmits a microwave driving signal;

[0070] S2: The energy harvesting unit supplies power to the ASIC;

[0071] S3: The ASIC in the sensor encodes the baseband information;

[0072] S4: The dedicated integrated circuit drives the analog switch matrix according to the coded information, so that the microwave frequency conversion device is connected to different frequency selection devices, so that the microwave frequency conversion device generates driven return signals with different frequencies, thereby realizing frequency shift keying modulation of the driven return signals;

[0073] S5: The transceiver receives and analyzes the modulated driven return signal and calculates the baseband signal.

[0074] Although the present invention is described herein with reference to the illustrative embodiments of the present invention, 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 apparent to those skilled in the art.

Claims

1. A frequency shift keying passive wireless sensor, characterized in that: Including, energy harvesting unit, application specific integrated circuit, switch matrix unit, frequency selection device, MDFC unit; The MDFC unit is connected to the switch matrix unit, and the MDFC unit includes a microwave frequency conversion device, and the microwave frequency conversion device is used to achieve mixing of the fed microwave signal and the oscillation signal in the transistor, thereby achieving passive frequency conversion; wherein the frequency of the oscillation signal is the resonant frequency of the frequency selection device; The energy collection unit is connected to a dedicated integrated circuit, and the dedicated integrated circuit is connected to a switch matrix unit; The common end of the switch matrix unit is connected to the microwave frequency conversion device, and the port of the switch matrix unit is connected to the frequency selection device, and the number of the frequency selection devices is 2 or more; wherein the dedicated integrated circuit encodes the baseband information and drives the switch matrix unit according to the encoded information, so that the microwave frequency conversion device is connected to different frequency selection devices.

2. A frequency shift keying passive wireless sensor as claimed in claim 1, characterized in that: The MDFC unit also includes an antenna, an input matching network, and a resonant network; The antenna is connected to an input matching network, and the input matching network and the resonant network are connected to a microwave frequency conversion device; The microwave frequency conversion device is connected to the common end of the switch matrix unit.

3. A frequency shift keying passive wireless sensor as claimed in claim 1, characterized in that: The energy collection unit includes one or both of a microwave energy conversion unit and a photovoltaic energy conversion unit.

4. A frequency shift keying passive wireless sensor as claimed in claim 3, characterized in that: The microwave energy conversion unit includes a microwave antenna, an energy collection unit, and a power management unit; The microwave antenna is connected to an energy collection unit, and the energy collection unit is connected to a power management unit.

5. A frequency shift keying passive wireless sensor as claimed in claim 1, characterized in that: The dedicated integrated circuit is a low-power MCU.

6. A frequency shift keying passive wireless sensor system, characterized in that: It comprises a frequency shift keying passive wireless sensor and a transceiver as described in any one of claims 1 to 5; The transceiver includes a transceiver module, a signal processing unit, and a power management unit, wherein the power management unit is connected to the transceiver module and the signal processing unit, and the transceiver module is connected to the signal processing unit; The transceiver module is used to transmit microwave driving signals, receive driven return signals, and send them to the signal processing unit; The signal processing unit is used to process the driven return signal and calculate the baseband signal and the sensor test result.

7. A frequency shift keying passive wireless sensor control method, based on the frequency shift keying passive wireless sensor system according to claim 6, characterized in that: The following steps are involved: The transceiver transmits a microwave drive signal; The energy harvesting unit supplies power to the ASIC; The ASIC in the sensor encodes the baseband information; The dedicated integrated circuit drives the analog switch matrix to connect the microwave frequency conversion device to different sensor elements, so that the microwave frequency conversion device generates driven return signals of different frequencies, thereby realizing frequency shift keying modulation of the driven return signals; The transceiver receives and analyzes the modulated driven return signal and calculates the baseband signal.

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