Frequency conversion signal receiving and transmitting module and passive wireless pressure sensor

Abstract

The invention discloses a frequency conversion signal receiving and transmitting module and a passive wireless pressure sensor, and belongs to the technical field of wireless monitoring. And the frequency conversion signal receiving and transmitting module converts the received downlink radio frequency signal sent by the reader into a frequency conversion uplink radio frequency signal and transmits the uplink radio frequency signal back to the reader. The passive wireless pressure sensor comprises the frequency conversion signal receiving and transmitting module; the pressure sensing module is used for acquiring and storing sensing data, and modulating the sensing data to an uplink radio frequency signal after receiving an instruction for reading the sensing data sent by the reader; and the power supply module is used for receiving a downlink radio frequency signal sent by the reader, converting the downlink radio frequency signal into direct current, storing the direct current and supplying power to the pressure sensing module. The frequency conversion signal receiving and transmitting module has the characteristic of different frequencies of uplink and downlink radio frequency signals, so that self-interference is avoided, the receiving sensitivity is improved, the wireless communication distance is expanded, and the communication coverage capability of a reader is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless monitoring, and particularly relates to a variable-frequency signal transceiver module and a passive wireless pressure sensor. Background Art

[0002] Passive Internet of Things (IoT) is an IoT technology that does not require an external power source or an internal battery. It powers passive tags by collecting environmental energy (such as radio frequency signals, light energy, thermal energy, vibration energy, etc.). For example, RFID tags operate using the radio frequency energy emitted by a reader. This characteristic gives it significant advantages in scenarios without a battery or power source (such as remote areas and extreme environments). Although RFID is a mature technology for passive IoT, its applications still face the following main problems: (1) High signal interference: Signal stability caused by self-interference of the same frequency for transmission and reception; (2) Weak coverage ability: The effective communication distance of traditional ultra-high frequency RFID is usually less than 10 meters, and it even shortens to 3 meters after being equipped with sensors. Summary of the Invention

[0003] The purpose of the present invention is to provide a variable-frequency signal transceiver module and a passive wireless pressure sensor to solve the problem of weak anti-interference ability of existing passive IoT.

[0004] The technical solution of the present invention to solve the above technical problems is as follows:

[0005] A variable-frequency signal transceiver module converts the received downlink radio frequency signal sent by a reader into a variable-frequency uplink radio frequency signal and transmits the uplink radio frequency signal back to the reader.

[0006] Further, the above variable-frequency signal transceiver module includes:

[0007] A first antenna, which is used to receive the downlink radio frequency signal sent by the reader and transmit it, and is also used to transmit the received uplink radio frequency signal back to the reader;

[0008] A circulator, which is used to receive the downlink radio frequency signal sent by the first antenna and transmit it, and is also used to transmit the received uplink radio frequency signal to the first antenna;

[0009] And a variable-frequency circuit, which is used to receive the downlink radio frequency signal sent by the circulator, start working under the drive of the power of the downlink radio frequency signal, generate a variable-frequency uplink radio frequency signal, and is also used to transmit the variable-frequency uplink radio frequency signal to the circulator.

[0010] Further, the above variable-frequency circuit includes a port P1, a first matching network, a radio frequency diode, a second matching network, and a port P2 connected in sequence, where the positive and negative electrodes of the radio frequency diode are respectively connected to the first matching network and the second matching network;

[0011] Port 1 (P1) is used to receive the downlink RF signal sent by the circulator;

[0012] Port 2 (P2) is used to transmit the frequency-converted uplink RF signal;

[0013] The first matching network is used to reduce the transmission loss of the downlink RF signal from the circulator to the RF diode;

[0014] The second matching network is used to reduce the transmission loss of the uplink RF signal output from the RF diode and block the downlink RF signal from reaching Port 2 (P2).

[0015] Furthermore, the frequency of the above-mentioned uplink RF signal is twice the frequency of the downlink RF signal.

[0016] Furthermore, the above-mentioned frequency conversion circuit further includes a first switch component. The first end of the first switch component is connected to the negative electrode of the RF diode, the second end is connected to Port 3 (P3), Port 3 (P3) is used to receive a control instruction, and the third end is grounded.

[0017] Furthermore, the above-mentioned frequency conversion circuit further includes a second switch component. The first end of the second switch component is connected to the negative electrode of the RF diode, the second end is connected to the second matching network, and the third end is connected to Port 3 (P3), Port 3 (P3) is used to receive a control instruction.

[0018] Furthermore, the above-mentioned first matching network includes an inductor L1 and a capacitor C1; the first end of the inductor L1 is connected to Port 1 (P1), and the second end of the inductor L1 is electrically connected to the positive electrode of the RF diode; the first end of the capacitor C1 is connected to the second end of the inductor L1, and the second end of the capacitor C1 is grounded;

[0019] The second matching network includes a capacitor C2 and an inductor L2; the first end of the capacitor C2 is connected to Port 2 (P2), the second end of the capacitor C2 is connected to the negative electrode of the RF diode; the first end of the inductor L2 is connected to the second end of the capacitor C2, and the second end of the inductor L2 is grounded.

[0020] A passive wireless pressure sensor includes:

[0021] The above-mentioned frequency conversion signal transceiver module;

[0022] A pressure sensing module, which is used to acquire and save sensing data, and modulate the sensing data onto the uplink RF signal after receiving the instruction to read the sensing data sent by the reader;

[0023] And a power supply module, which is used to receive the downlink RF signal sent by the reader, convert it into direct current for storage, and supply power to the pressure sensing module.

[0024] Furthermore, the above-mentioned pressure sensing module includes:

[0025] A pressure sensing unit for obtaining sensing data;

[0026] A main control unit powered by a power supply module, for collecting the sensing data of the pressure sensing unit and transmitting it;

[0027] And a memory for storing the sensing data;

[0028] After receiving the instruction from the reader to read the sensing data, the main control unit modulates the sensing data onto the uplink radio frequency signal.

[0029] Furthermore, the above power supply module includes:

[0030] A second antenna for receiving the downlink radio frequency signal sent by the reader and transmitting it;

[0031] And a power management circuit for receiving the downlink radio frequency signal and converting it into direct current for storage to supply power to the main control unit.

[0032] The present invention has the following beneficial effects:

[0033] (1) The frequency conversion signal transceiver module of the present invention has the characteristic that the uplink and downlink radio frequency signals have different frequencies. Specifically, the downlink radio frequency signal sent by the reader to the tag is different from the uplink radio frequency signal sent by the tag to the reader, so as to avoid the leakage downlink radio frequency signal at the transmitter end of the reader from drowning out the uplink radio frequency signal, largely avoiding self-interference, and correspondingly improving the receiving sensitivity of the reader to the uplink radio frequency signal, thus expanding the wireless communication distance and enhancing the communication coverage ability of the reader.

[0034] (2) The sensing data of the present invention adopts the method of modulating the amplitude of the uplink radio frequency signal. After the reader receives the modulated uplink radio frequency signal, the corresponding sensing data can be obtained by parsing. Compared with the wireless transmission of analog data, it has higher anti-interference ability, higher reliability and stronger stability. Description of the Drawings

[0035] Figure 1 It is a schematic structural diagram of the frequency conversion signal transceiver module of Embodiment 1 of the present invention;

[0036] Figure 2 It is a schematic structural diagram of the frequency conversion circuit of Embodiment 1 of the present invention;

[0037] Figure 3 It is a specific schematic structural diagram of the frequency conversion circuit of Embodiment 1 of the present invention;

[0038] Figure 4 It is a schematic structural diagram of the frequency conversion circuit of Embodiment 2 of the present invention;

[0039] Figure 5 This is a schematic structural diagram of the passive wireless pressure sensor according to Embodiment 3 of the present invention.

[0040] In the figure: 11 - first antenna; 12 - circulator; 13 - frequency conversion circuit; 14 - main control unit; 15 - pressure sensing unit; 16 - memory; 17 - power management circuit; 18 - second antenna; 134 - RF diode; 136 - first matching network; 137 - second matching network; 138 - first switch component; 1361 - inductor one; 1362 - capacitor one; 1371 - capacitor two; 1372 - inductor two; 141 - second switch component. Detailed implementation manners

[0041] The principles and features of the present invention will be described below with reference to the accompanying drawings. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0042] Embodiment 1:

[0043] Please refer to Figures 1 to 3 , this embodiment provides a frequency conversion signal transceiver module. This frequency conversion signal transceiver module converts the received downlink RF signal sent by the reader into a frequency-converted uplink RF signal and returns the uplink RF signal to the reader. It can be seen that the frequency conversion signal transceiver module of the present invention has the characteristic of different frequencies for the downlink and uplink RF signals. Specifically, the downlink RF signal sent by the reader to the tag is different from the uplink RF signal sent by the tag to the reader, thereby avoiding the leakage downlink RF signal at the transmitter end of the reader from drowning out the uplink RF signal, largely avoiding self-interference, and correspondingly improving the receiving sensitivity of the reader to the uplink RF signal, thus expanding the wireless communication distance and enhancing the communication coverage ability of the reader.

[0044] In this embodiment, the frequency conversion signal transceiver module includes:

[0045] The first antenna 11, the first antenna 11 is used to receive the downlink RF signal sent by the reader and transmit it, and is also used to return the received uplink RF signal to the reader;

[0046] The circulator 12, the circulator 12 is connected to the first antenna 11, and is used to receive the downlink RF signal sent by the first antenna 11 and transmit it, and is also used to transmit the received uplink RF signal to the first antenna 11;

[0047] And the frequency conversion circuit 13, the frequency conversion circuit 13 is connected to the circulator 12, and is used to receive the downlink RF signal sent by the circulator 12, start to work under the drive of the downlink RF signal power, generate a frequency-converted uplink RF signal, and is also used to transmit the frequency-converted uplink RF signal to the circulator 12.

[0048] The frequency conversion circuit 13 includes a port P1, a first matching network 136, a radio frequency diode 134, a second matching network 137, and a port P2, which are connected in sequence. The port P1 is connected to the circulator 12 and is used to receive the downlink radio frequency signal sent by the circulator 12. The port P2 is also connected to the circulator 12 and is used to send the frequency-converted uplink radio frequency signal to the circulator 12. The first matching network 136 is used to reduce the transmission loss of the downlink radio frequency signal from the circulator 12 to the radio frequency diode 134, and the second matching network 137 is used to reduce the transmission loss of the uplink radio frequency signal output from the radio frequency diode 134 and block the downlink radio frequency signal from reaching the port P2.

[0049] In this embodiment, the radio frequency diode 134 is used as a frequency doubling element. Preferably, it is used to perform frequency conversion on the received downlink radio frequency signal, that is, the frequency of the uplink radio frequency signal is twice the frequency of the downlink radio frequency signal. For example, the frequency of the downlink radio frequency signal can be 433 MHz, and correspondingly, the frequency of the uplink radio frequency signal is 866 MHz.

[0050] Among them, the first matching network 136 includes an inductor L1 1361 and a capacitor C1 1362. The first end of the inductor L1 1361 is connected to the port P1, and the second end of the inductor L1 1361 is electrically connected to the positive electrode of the radio frequency diode 134; the first end of the capacitor C1 1362 is connected to the second end of the inductor L1 1361, and the second end of the capacitor C1 1362 is grounded.

[0051] Among them, the second matching network 137 includes a capacitor C2 1371 and an inductor L2 1372; the first end of the capacitor C2 1371 is connected to the port P2, and the second end of the capacitor C2 1371 is connected to the negative electrode of the radio frequency diode 134; the first end of the inductor L2 1372 is connected to the second end of the capacitor C2 1371, and the second end of the inductor L2 1372 is grounded.

[0052] In this embodiment, the frequency conversion circuit 13 further includes a first switch component 138. The first end of the first switch component 138 is connected to the negative electrode of the radio frequency diode 134, the second end is connected to a port P3, and the port P3 is used to receive a control instruction, and the third end is grounded.

[0053] Embodiment 2:

[0054] Please refer to Figure 4 , this embodiment also provides a frequency conversion signal transceiver module, which is different from that of Embodiment 1 in the setting of the switch component. In this embodiment, the frequency conversion circuit 13 includes a second switch component 141. The first end of the second switch component 141 is connected to the negative electrode of the radio frequency diode 134, the second end is connected to the second end of the capacitor C1 1362, and the third end is connected to a port P3, and the port P3 is used to receive a control instruction.

[0055] Embodiment 3:

[0056] Please refer to Figure 5 , this embodiment provides a passive wireless pressure sensor, including:

[0057] The frequency conversion signal transceiver module of Embodiment 1 or Embodiment 2;

[0058] A pressure sensing module, which is used to acquire and save sensing data, and modulate the sensing data onto the uplink radio frequency signal after receiving the instruction sent by the reader to read the sensing data;

[0059] And a power supply module, which is used to receive the downlink radio frequency signal sent by the reader, convert it into direct current for storage, and supply power to the pressure sensing module.

[0060] Among them, the pressure sensing module includes:

[0061] A pressure sensing unit 15, which is used to acquire sensing data;

[0062] A main control unit 14, which is powered by the power supply module, and is used to collect the sensing data of the pressure sensing unit 15 and transmit it;

[0063] And a memory 16, which is used to save sensing data.

[0064] The main control unit 14 sends the collected sensing data to the memory 16 for storage. At the same time, after the main control unit 14 receives the instruction sent by the reader to read the sensing data, the main control unit 14 will control the on / off of the switch component (the first switch component 138 or the second switch component 141) according to the binary sensing data, so as to realize the amplitude modulation of the uplink radio frequency signal. After the reader receives the modulated uplink radio frequency signal, the corresponding sensing data can be obtained by parsing. Compared with the analog data wireless transmission, this solution has higher anti-interference ability, higher reliability and stronger stability.

[0065] Among them, the power supply module includes:

[0066] A second antenna 18, which is used to receive the downlink radio frequency signal sent by the reader and transmit it;

[0067] And a power management circuit 17, which is used to receive the downlink radio frequency signal and convert it into direct current for storage, and supply power to the main control unit 14.

[0068] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A variable frequency signal transceiver module, characterized in that: The frequency conversion signal transceiver module converts the received downlink radio frequency signal sent by the reader into a frequency conversion uplink radio frequency signal, and transmits the uplink radio frequency signal back to the reader.

2. The frequency conversion signal transceiver module according to claim 1, characterized in that: include: a first antenna, the first antenna being used to receive and transmit a downlink radio frequency signal sent by the reader, and also being used to transmit the received uplink radio frequency signal back to the reader; a circulator, the circulator being used to receive and transmit a downlink radio frequency signal sent by the first antenna, and also being used to transmit a received uplink radio frequency signal to the first antenna; And a frequency conversion circuit, which is used to receive the downlink radio frequency signal sent by the circulator, start working under the drive of the downlink radio frequency signal power, generate a frequency-converted uplink radio frequency signal, and transmit the frequency-converted uplink radio frequency signal to the circulator.

3. The frequency conversion signal transceiver module according to claim 2, characterized in that: The frequency conversion circuit comprises a port 1 P1, a first matching network, a radio frequency diode, a second matching network and a port 2 P2 which are connected in sequence, wherein the positive electrode and the negative electrode of the radio frequency diode are connected to the first matching network and the second matching network respectively; Port 1 P1 is used to receive the downlink RF signal sent by the circulator; Port 2 P2 is used to send uplink RF signals with variable frequency; The first matching network is used to reduce the transmission loss of the downlink radio frequency signal from the circulator to the radio frequency diode; The second matching network is used to reduce the transmission loss of the uplink radio frequency signal output from the radio frequency diode and to block the downlink radio frequency signal from reaching the port two P2.

4. The frequency conversion signal transceiver module according to claim 3, characterized in that: The frequency of the uplink RF signal is twice the frequency of the downlink RF signal.

5. The frequency conversion signal transceiver module according to claim 4, characterized in that: The frequency conversion circuit also includes a first switch component, a first end of which is connected to the cathode of the radio frequency diode, a second end of which is connected to port three P3, port three P3 is used to receive control instructions, and a third end is grounded.

6. The frequency conversion signal transceiver module according to claim 4, characterized in that: The frequency conversion circuit also includes a second switch component, a first end of the second switch component is connected to the cathode of the RF diode, a second end is connected to the second matching network, and a third end is connected to port three P3, and port three P3 is used to receive control instructions.

7. The variable frequency signal transceiver module according to any one of claims 3 to 6, characterized in that: The first matching network includes an inductor 1 and a capacitor 1; a first end of the inductor 1 is connected to the port 1 P1, and a second end of the inductor 1 is electrically connected to the positive electrode of the radio frequency diode; a first end of the capacitor 1 is connected to the second end of the inductor 1, and a second end of the capacitor 1 is grounded; The second matching network includes capacitor 2 and inductor 2; the first end of capacitor 2 is connected to port 2 P2, and the second end of capacitor 2 is connected to the cathode of the RF diode; the first end of inductor 2 is connected to the second end of capacitor 2, and the second end of inductor 2 is grounded.

8. A passive wireless pressure sensor, characterized in that: include: The variable frequency signal transceiver module according to any one of claims 1 to 7; A pressure sensing module, which is used to obtain and store sensing data, and after receiving an instruction to read the sensing data from the reader, modulate the sensing data onto an uplink radio frequency signal; And a power supply module, which is used to receive the downlink radio frequency signal sent by the reader and convert it into direct current for storage to power the pressure sensor module.

9. The passive wireless pressure sensor according to claim 8, characterized in that: The pressure sensing module comprises: A pressure sensing unit, wherein the pressure sensing unit is used to obtain sensing data; A main control unit, which is powered by a power supply module and is used to collect and transmit sensing data from the pressure sensing unit; and a memory, the memory being used to store the sensing data; After receiving the instruction to read the sensor data from the reader, the main control unit modulates the sensor data onto the uplink radio frequency signal.

10. The passive wireless pressure sensor according to claim 9, characterized in that: The power supply module comprises: a second antenna, the second antenna being used to receive and transmit a downlink radio frequency signal sent by the reader; And a power management circuit, which is used to receive the downlink radio frequency signal and convert it into direct current for storage to power the main control unit.

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