Frequency conversion circuit, frequency conversion signal transceiving module and passive wireless pressure sensor

Abstract

The utility model discloses a frequency conversion circuit, a frequency conversion signal transmit-receive module and a passive wireless pressure sensor, belonging to the technical field of wireless monitoring, the passive wireless pressure sensor comprises a frequency conversion signal transmit-receive module, a pressure sensing module and a power supply module, the frequency conversion signal transmit-receive module comprises a first antenna, a circulator and a frequency conversion circuit, and the frequency conversion circuit converts the downlink radio-frequency signal into a frequency-converted uplink radio-frequency signal and transmits the frequency-converted uplink radio-frequency signal back. The frequency conversion circuit provided by the utility model has the characteristic of different frequencies of uplink and downlink radio frequency signals, avoids self-interference, improves the receiving sensitivity, expands the wireless communication distance, and improves the communication coverage capability of a reader.

Description

Technical Field

[0001] This utility model relates to the field of wireless monitoring technology, specifically to a frequency conversion circuit, a frequency conversion signal transceiver module, and a passive wireless pressure sensor. Background Technology

[0002] Passive Internet of Things (IoT) is an IoT technology that does not require an external power source or built-in battery. It powers passive tags by collecting environmental energy (such as radio frequency signals, light energy, heat energy, vibration energy, etc.). For example, RFID tags work using the radio frequency energy emitted by the reader. This characteristic gives them a significant advantage in scenarios without batteries or power sources (such as remote areas or extreme environments). Although RFID is a mature technology for passive IoT, its application still faces the following major problems: (1) Significant signal interference: signal stability is caused by self-interference between the transmitter and receiver at the same frequency; (2) Weak coverage: the effective communication distance of traditional UHF RFID is usually less than 10 meters, and even reduced to 3 meters after the addition of sensors. Utility Model Content

[0003] The purpose of this invention is to provide a frequency conversion circuit, a frequency conversion signal transceiver module, and a passive wireless pressure sensor to solve the problem of weak anti-interference capability of existing passive Internet of Things (IoT) devices.

[0004] The technical solution of this utility model to solve the above-mentioned technical problems is as follows:

[0005] A frequency converter circuit includes a port P1, a first matching network, an RF diode, a second matching network, and a port P2 connected in sequence, wherein the positive and negative terminals of the RF diode are connected to the first matching network and the second matching network, respectively.

[0006] Port P1 is used to receive downlink radio frequency signals sent by the circulator;

[0007] Port 2 P2 is used to transmit the uplink RF signal of the frequency converter;

[0008] The first matching network is used to reduce the transmission loss of the downlink RF signal from the circulator to the RF diode;

[0009] The second matching network is used to reduce the transmission loss of the uplink RF signal output from the RF diode and to block the downlink RF signal from reaching port 2P2.

[0010] The frequency conversion circuit is used to receive downlink radio frequency signals and start working under the power drive of the downlink radio frequency signal to generate frequency-converted uplink radio frequency signals. It is also used to transmit the frequency-converted uplink radio frequency signals to the outside world.

[0011] Furthermore, the frequency of the aforementioned uplink radio frequency signal is twice the frequency of the downlink radio frequency signal.

[0012] Furthermore, the downlink radio frequency signal frequency is 433MHz and the uplink radio frequency signal frequency is 866MHz.

[0013] Furthermore, the aforementioned frequency conversion circuit also includes a first switching assembly. The first end of the first switching assembly is connected to the negative terminal of the radio frequency diode, the second end is connected to port 3P3, port 3P3 is used to receive control commands, and the third end is grounded.

[0014] Furthermore, the aforementioned frequency conversion circuit also includes a second switching assembly. The first end of the second switching assembly is connected to the negative terminal of the RF diode, the second end is connected to the second matching network, and the third end is connected to port 3P3, which is used to receive control commands.

[0015] Furthermore, the aforementioned first matching network includes an inductor and a capacitor; the first end of the inductor is connected to port P1, and the second end of the inductor is electrically connected to the positive terminal of the RF diode; the first end of the capacitor is connected to the second end of the inductor, and the second end of the capacitor is grounded.

[0016] The second matching network includes capacitor two and inductor two; the first end of capacitor two is connected to port two P2, and the second end of capacitor two is connected to the negative terminal of the RF diode; the first end of inductor two is connected to the second end of capacitor two, and the second end of inductor two is grounded.

[0017] A frequency conversion signal transceiver module, comprising:

[0018] The first antenna is used to receive and transmit downlink radio frequency signals sent by the reader, and also to transmit the received uplink radio frequency signals back to the reader.

[0019] The circulator is used to receive and transmit downlink radio frequency signals sent by the first antenna, and also to transmit the received uplink radio frequency signals to the first antenna.

[0020] The aforementioned frequency conversion circuit is used to receive the downlink radio frequency signal sent by the circulator and transmit the frequency-converted uplink radio frequency signal to the circulator.

[0021] A passive wireless pressure sensor, comprising:

[0022] The aforementioned frequency conversion signal transceiver module;

[0023] The pressure sensing module is used to acquire and save sensing data. After receiving the instruction from the reader to read the sensing data, the sensing data is modulated onto the uplink radio frequency signal.

[0024] And a power supply module, which receives the downlink radio frequency signal sent by the reader and converts it into DC power for storage to power the pressure sensing module.

[0025] Furthermore, the aforementioned pressure sensing module includes:

[0026] Pressure sensing unit, used to acquire sensing data;

[0027] The main control unit, powered by the power supply module, is used to collect and transmit the sensing data from the pressure sensing unit.

[0028] And memory, which is used to store sensor data;

[0029] After receiving the instruction from the reader to read the sensor data, the main control unit modulates the sensor data onto the uplink radio frequency signal.

[0030] Furthermore, the aforementioned power supply module includes:

[0031] The second antenna is used to receive and transmit the downlink radio frequency signals sent by the reader.

[0032] It also includes a power management circuit, which receives downlink radio frequency signals and converts them into DC power for storage, thus powering the main control unit.

[0033] This utility model has the following beneficial effects:

[0034] (1) The frequency conversion circuit of this utility model has the feature of different frequencies for uplink and downlink radio frequency signals. 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. This can prevent the downlink radio frequency signal from being overwhelmed by the uplink radio frequency signal at the transmitter end of the reader, thus avoiding self-interference to a large extent. Correspondingly, it improves the reader's sensitivity to receiving uplink radio frequency signals, thereby extending the wireless communication distance and improving the reader's communication coverage capability.

[0035] (2) The sensing data of this utility model adopts the method of modulating the amplitude of the uplink radio frequency signal. After the reader receives the modulated uplink radio frequency signal, it can obtain the corresponding sensing data by parsing it. Compared with analog data wireless transmission, it has higher anti-interference ability, higher reliability, and stronger stability. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the frequency conversion circuit of Embodiment 1 of this utility model;

[0037] Figure 2 This is a schematic diagram of the specific structure of the frequency conversion circuit in Embodiment 1 of this utility model;

[0038] Figure 3 This is a schematic diagram of the frequency conversion circuit in Embodiment 2 of this utility model;

[0039] Figure 4 This is a schematic diagram of the structure of the frequency conversion signal transceiver module in Embodiment 3 of this utility model;

[0040] Figure 5 This is a schematic diagram of the passive wireless pressure sensor of Embodiment 4 of this utility model.

[0041] In the diagram: 11-First antenna; 12-Circuit 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 switching assembly; 1361-Inductor 1; 1362-Capacitor 1; 1371-Capacitor 2; 1372-Inductor 2; 141-Second switching assembly. Detailed Implementation

[0042] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are only for explaining this utility model and are not intended to limit the scope of this utility model.

[0043] Example 1:

[0044] Please refer to Figure 1 and Figure 2 This embodiment provides a frequency converter circuit, which includes a port P1, a first matching network 136, an RF diode 134, a second matching network 137, and a port P2 connected in sequence. Port P1 is connected to a circulator 12 and is used to receive the downlink RF signal sent by the circulator 12. Port P2 is also connected to the circulator 12 and is used to send the frequency-converted uplink RF signal to the circulator 12. The first matching network 136 is used to reduce the transmission loss of the downlink RF signal from the circulator 12 to the RF diode 134. The second matching network 137 is used to reduce the transmission loss of the uplink RF signal output from the RF diode 134 and to block the downlink RF signal from reaching port P2.

[0045] The frequency conversion circuit receives downlink RF signals and starts working under the power of the downlink RF signal to generate a frequency-converted uplink RF signal. It also transmits the frequency-converted uplink RF signal externally. This invention's frequency conversion circuit features different frequencies for the uplink and downlink 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. This avoids the downlink RF signal from leaking into the transmitter of the reader and drowning out the uplink RF signal, greatly reducing self-interference. Correspondingly, this improves the reader's sensitivity to receiving uplink RF signals, thereby extending the wireless communication distance and enhancing the reader's communication coverage.

[0046] In this embodiment, the radio frequency diode 134 is used as a frequency multiplier. Preferably, the radio frequency diode 134 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 downlink radio frequency signal frequency can be 433MHz, and correspondingly, the uplink radio frequency signal frequency is 866MHz.

[0047] The first matching network 136 includes an inductor 1361 and a capacitor 1362. The first end of the inductor 1361 is connected to port P1, and the second end of the inductor 1361 is electrically connected to the positive terminal of the RF diode 134. The first end of the capacitor 1362 is connected to the second end of the inductor 1361, and the second end of the capacitor 1362 is grounded.

[0048] The second matching network 137 includes a capacitor 1371 and an inductor 1372. The first end of the capacitor 1371 is connected to port P2, and the second end of the capacitor 1371 is connected to the negative terminal of the RF diode 134. The first end of the inductor 1372 is connected to the second end of the capacitor 1371, and the second end of the inductor 1372 is grounded.

[0049] In this embodiment, the frequency conversion circuit 13 further includes a first switching component 138. The first end of the first switching component 138 is connected to the negative terminal of the radio frequency diode 134, the second end is connected to port 3P3, port 3P3 is used to receive control commands, and the third end is grounded.

[0050] Example 2:

[0051] Please refer to Figure 3 This embodiment also provides a frequency conversion signal transceiver module, which differs from Embodiment 1 in that the setting of the switching components is different. In this embodiment, the frequency conversion circuit 13 includes a second switching component 141. The first end of the second switching component 141 is connected to the negative terminal of the radio frequency diode 134, the second end is connected to the second end of the capacitor 1362, and the third end is connected to port 3P3, which is used to receive control commands.

[0052] Example 3:

[0053] Please refer to Figure 4 This embodiment provides a frequency conversion signal transceiver module, which converts the downlink radio frequency signal received from the reader into a frequency conversion uplink radio frequency signal and sends the uplink radio frequency signal back to the reader.

[0054] The frequency converter signal transceiver module includes:

[0055] The first antenna 11 is used to receive and transmit the downlink radio frequency signal sent by the reader, and also to transmit the received uplink radio frequency signal back to the reader.

[0056] Circulator 12 is connected to the first antenna 11 and is used to receive and transmit downlink radio frequency signals sent by the first antenna 11, and also to transmit the received uplink radio frequency signals to the first antenna 11.

[0057] And the frequency conversion circuit 13 of embodiment 1 or 2, which is connected to the circulator 12, is used to receive the downlink radio frequency signal sent by the circulator 12, and start working under the power drive of the downlink radio frequency signal to generate the frequency conversion uplink radio frequency signal, and is also used to transmit the frequency conversion uplink radio frequency signal to the circulator 12.

[0058] Example 4:

[0059] Please refer to Figure 5 This embodiment provides a passive wireless pressure sensor, including:

[0060] Variable frequency signal transceiver module of Example 3;

[0061] The pressure sensing module is used to acquire and save sensing data. After receiving the instruction from the reader to read the sensing data, the sensing data is modulated onto the uplink radio frequency signal.

[0062] And a power supply module, which receives the downlink radio frequency signal sent by the reader and converts it into DC power for storage to power the pressure sensing module.

[0063] The pressure sensing module includes:

[0064] Pressure sensing unit 15, pressure sensing unit 15 is used to acquire sensing data;

[0065] The main control unit 14 is powered by a power supply module and is used to collect and transmit the sensing data of the pressure sensing unit 15.

[0066] And memory 16, which is used to store sensing data.

[0067] The main control unit 14 sends the collected sensor data to the memory 16 for storage. Simultaneously, upon receiving a command from the reader to read the sensor data, the main control unit 14 controls the switching components (first switch component 138 or second switch component 141) based on the binary sensor data, thereby modulating the amplitude of the uplink radio frequency signal. After receiving the modulated uplink radio frequency signal, the reader can parse it to obtain the corresponding sensor data. Compared to analog wireless data transmission, this solution has higher anti-interference capability, higher reliability, and stronger stability.

[0068] The power supply module includes:

[0069] The second antenna 18 is used to receive and transmit the downlink radio frequency signal sent by the reader;

[0070] And power management circuit 17, which is used to receive downlink radio frequency signals and convert them into DC power for storage, so as to power the main control unit 14.

[0071] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A frequency conversion circuit, characterized by The variable frequency circuit comprises a port one P1, a first matching network, a radio frequency diode, a second matching network and a port two P2 connected in sequence, wherein the positive and negative poles of the radio frequency diode are connected with the first matching network and the second matching network respectively; The port one P1 is used for receiving the downlink radio frequency signal transmitted by the circulator; The port two P2 is used for transmitting the uplink radio frequency signal after frequency conversion; The first matching network is used for reducing the transmission loss of the downlink radio frequency signal from the circulator to the radio frequency diode; The second matching network is used for reducing the transmission loss of the uplink radio frequency signal output from the radio frequency diode and blocking the downlink radio frequency signal from reaching the port two P2; The variable frequency circuit is used for receiving the downlink radio frequency signal and starting to work under the power driving of the downlink radio frequency signal to generate the uplink radio frequency signal after frequency conversion, and is also used for transmitting the uplink radio frequency signal after frequency conversion to the outside.

2. The frequency conversion circuit of claim 1, wherein, The frequency of the uplink radio frequency signal is twice the frequency of the downlink radio frequency signal.

3. The frequency varying circuit of claim 2, wherein, The frequency of the downlink radio frequency signal is 433 MHz, and the frequency of the uplink radio frequency signal is 866 MHz.

4. The frequency varying circuit of claim 1, wherein, The variable frequency circuit further comprises a first switch assembly, the first end of the first switch assembly is connected with the negative pole of the radio frequency diode, the second end is connected with the port three P3, the port three P3 is used for receiving a control instruction, and the third end is grounded.

5. The frequency varying circuit of claim 1, wherein, The variable frequency circuit further comprises a second switch assembly, the first end of the second switch assembly is connected with the negative pole of the radio frequency diode, the second end is connected with the second matching network, the third end is connected with the port three P3, and the port three P3 is used for receiving a control instruction.

6. The frequency conversion circuit of claim 4 or 5, wherein, The first matching network comprises an inductor one and a capacitor one; the first end of the inductor one is connected with the port one P1, the second end of the inductor one is electrically connected with the positive pole of the radio frequency diode; the first end of the capacitor one is connected with the second end of the inductor one, and the second end of the capacitor one is grounded. The second matching network comprises a capacitor two and an inductor two; the first end of the capacitor two is connected with the port two P2, the second end of the capacitor two is connected with the negative pole of the radio frequency diode; the first end of the inductor two is connected with the second end of the capacitor two, and the second end of the inductor two is grounded.

7. A frequency-agile transceiver module, characterized by It comprises: A first antenna, which is used for receiving the downlink radio frequency signal transmitted by a reader and transmitting, and is also used for transmitting the received uplink radio frequency signal back to the reader; A circulator, which is used for receiving the downlink radio frequency signal transmitted by the first antenna and transmitting, and is also used for transmitting the received uplink radio frequency signal to the first antenna; And the variable frequency circuit of any one of claims 1 to 6, which is used for receiving the downlink radio frequency signal transmitted by the circulator and transmitting the uplink radio frequency signal after frequency conversion to the circulator.

8. A passive wireless pressure sensor, characterized by It comprises: The variable frequency signal transceiving module of claim 7; A pressure sensing module, which is used for acquiring sensing data and saving, and modulating the sensing data on the uplink radio frequency signal after receiving the instruction of reading the sensing data transmitted by the reader; And a power supply module, which is used for receiving the downlink radio frequency signal transmitted by the reader and converting into direct current for storage to supply power for the pressure sensing module.

9. The passive wireless pressure sensor of claim 8, wherein, The pressure sensing module comprises: A pressure sensing unit, which is used for acquiring sensing data; A master control unit powered by a power supply module, configured to collect and transmit sensing data of the pressure sensing unit; and a memory configured to store the sensing data; After receiving the instruction of reading the sensing data sent by the reader, the master control unit modulates the sensing data onto the uplink radio frequency signal.

10. The passive wireless pressure sensor of claim 9, wherein, The power supply module comprises: A second antenna configured to receive and transmit the downlink radio frequency signal sent by the reader; and a power management circuit configured to receive the downlink radio frequency signal and convert it into direct current for storage, thereby powering the master control unit.

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