An active corner reflector and monitoring system

Abstract

This application relates to the field of radar monitoring technology, specifically providing an active corner reflector and a monitoring system. The active corner reflector includes: a receiving unit for receiving electromagnetic wave signals; a first signal amplification unit for amplifying the electromagnetic wave signals to obtain a first amplified signal; a phase-shifting unit for adjusting the phase of the first amplified signal to obtain a phase-shifted signal; a second signal amplification unit for amplifying the phase-shifted signal to obtain a second amplified signal; and a transmitting unit for transmitting the second amplified signal, wherein the second amplified signal returns along the original path of the electromagnetic wave signal. The receiving unit, the first signal amplification unit, the phase-shifting unit, the second signal amplification unit, and the transmitting unit are electrically connected in sequence. The technical solution provided by this application simplifies the installation of the monitoring system and greatly improves the system's measurement accuracy and range.

Description

Technical Field

[0001] This application relates to the field of radar monitoring technology, specifically providing an active corner reflector and a monitoring system. Background Technology

[0002] In infrastructure such as bridges, tunnels, and mines, even minor displacements can trigger major safety accidents. In recent years, news reports of collapses in these facilities causing enormous loss of life and property have been frequent. Therefore, timely warnings and evacuation of people when these facilities experience displacement or deformation have become a crucial aspect of ensuring the safety of these infrastructures.

[0003] In the existing technology, displacement detection radar is one of the commonly used monitoring methods, while passive corner reflectors are relatively common monitoring devices due to their low cost, simple structure, and ease of installation on the surface of the infrastructure being measured. However, due to the limitations of the structure and working principle of passive corner reflectors, the monitoring system has the following defects: (1) The system monitoring area is positively correlated with the installation size of the corner reflector, and the monitoring range is limited by the complex terrain; (2) The corner reflector has strict installation angle limitations, resulting in a long system installation and debugging time; (3) The corner reflector cannot automatically adjust the phase shift to achieve aiming, resulting in a large system measurement error; (4) The corner reflector does not have signal processing capabilities and cannot achieve multi-point measurement at the same time.

[0004] It is evident that the aforementioned technical problems with existing passive corner reflectors result in complex installation and debugging of the monitoring system, low measurement accuracy, and limited measurement range. Summary of the Invention

[0005] To address the aforementioned technical problems, this application proposes an active corner reflector and monitoring system, which can effectively overcome the technical defects of passive corner reflectors due to their structure and working principle, making the monitoring system easy to install and greatly improving the system's measurement accuracy and range.

[0006] To achieve the above objectives, the technical solution of this application is implemented as follows:

[0007] In a first aspect, this application provides an active corner reflector, comprising:

[0008] The receiving unit is used to receive electromagnetic wave signals;

[0009] The first signal amplification unit is used to amplify the power of the electromagnetic wave signal to obtain the first amplified signal;

[0010] The phase-shifting unit is used to adjust the phase of the first amplified signal to obtain the phase-shifted signal;

[0011] The second signal amplification unit is used to amplify the phase-shifted signal to obtain a second amplified signal.

[0012] The transmitting unit is used to transmit a second amplified signal, wherein the second amplified signal returns along the original path of the electromagnetic wave signal;

[0013] The receiving unit, the first signal amplification unit, the phase shifting unit, the second signal amplification unit, and the transmitting unit are electrically connected in sequence.

[0014] In some embodiments, the active corner reflector further includes: a first attenuator; the first attenuator is disposed between the first signal amplification unit and the phase shifting unit;

[0015] The first attenuator is used to reduce the power of the first amplified signal to obtain an attenuated signal;

[0016] The phase-shifting unit is used to adjust the phase of the attenuated signal to obtain a phase-shifted signal.

[0017] In some embodiments, the first signal amplification unit includes: a first low-noise amplifier and a first filter; the input terminal of the first low-noise amplifier is electrically connected to the output terminal of the receiving unit, and the output terminal of the first low-noise amplifier is electrically connected to the input terminal of the first filter; the output terminal of the first filter is electrically connected to the input terminal of the first attenuator.

[0018] In some embodiments, the phase shifting unit includes: a phase shifter and a control unit; the input terminal of the phase shifter is electrically connected to the output terminal of the first attenuator, and the output terminal of the phase shifter is electrically connected to the input terminal of the second signal amplification unit; the input terminal of the phase shifter is also electrically connected to the output terminal of the control unit.

[0019] The control unit is used to output phase adjustment information to control the phase shifter to adjust the phase of the attenuation signal according to the phase adjustment information, so as to obtain the phase-shifted signal.

[0020] In some embodiments, the phase shifter is a digital phase shifter; the control unit includes a first processor; the input terminal of the digital phase shifter is also electrically connected to the output terminal of the first processor; the phase adjustment information includes a phase adjustment amount;

[0021] The first processor is used to output the phase adjustment amount to control the digital phase shifter to adjust the phase of the attenuated signal according to the phase adjustment amount, so as to obtain the phase-shifted signal.

[0022] In some embodiments, the phase shifter is an analog phase shifter; the control unit includes: a second processor, a digital-to-analog converter, and an operational amplifier connected in sequence; the input terminal of the analog phase shifter is also electrically connected to the output terminal of the operational amplifier; the phase adjustment information includes a phase adjustment amount;

[0023] The second processor is used to output the phase adjustment amount;

[0024] A digital-to-analog converter is used to convert phase adjustment amounts into analog signals;

[0025] Operational amplifiers are used to amplify analog signals to obtain amplified analog signals;

[0026] The second processor is also used to control the analog phase shifter to adjust the phase of the attenuated signal according to the amplified analog signal, so as to obtain the phase-shifted signal.

[0027] In some embodiments, the second signal amplification unit includes at least one first signal amplification unit; in the second signal amplification unit, when there are two or more first signal amplification units, each first signal amplification unit is electrically connected in sequence.

[0028] In some embodiments, a second attenuator is further provided between each first signal amplification unit; the topology of the second attenuator is a π-type circuit, or the topology of the second attenuator is a T-type circuit.

[0029] In some embodiments, the receiving unit is a radio frequency receiving antenna; the transmitting unit is a radio frequency transmitting antenna; and the electromagnetic wave signal is a circularly polarized radio frequency signal.

[0030] In a second aspect, this application provides a monitoring system, comprising: a radar device, and an active corner reflector according to any of the technical solutions in the first aspect described above; the active corner reflector is mounted at a target position on the surface of the object being measured; the radar device is used to perform the following operations:

[0031] Send electromagnetic wave signals to the target location;

[0032] Receive the second amplified signal returned by the active corner reflector;

[0033] The displacement and / or deformation of the target location are monitored based on the second amplified signal.

[0034] This application provides an active corner reflector and monitoring system. By incorporating a receiving unit, a first signal amplification unit, a phase shifting unit, a second signal amplification unit, and a transmitting unit, the active corner reflector can amplify the power and adjust the phase of the received electromagnetic wave signal, and can return the amplified signal along the original path of the electromagnetic wave signal. This effectively overcomes the technical problems of passive corner reflectors, which, due to their structure and working principle, can only passively reflect electromagnetic wave signals, leading to complex installation and debugging, low measurement accuracy, and limited measurement range in the monitoring system. The technical solution provided in this application simplifies the installation of the monitoring system and significantly improves the system's measurement accuracy and range. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0036] Figure 1 A structural block diagram of an active corner reflector provided in an embodiment of this application;

[0037] Figure 2 Another structural block diagram of the active corner reflector provided in the embodiments of this application;

[0038] Figure 3 A circuit diagram of an active corner reflector provided in an embodiment of this application;

[0039] Figure 4 Another circuit structure diagram of an active corner reflector provided in an embodiment of this application.

[0040] Figure label:

[0041] 11: Receiving unit; 12: First signal amplification unit; 13: Phase shifting unit; 14: Second signal amplification unit; 15: Transmitting unit; 16: First attenuator; 101: First RF receiving antenna; 102: First low-noise amplifier; 103: First bandpass filter; 104: First 3dB attenuator; 105: First phase shifter; 106: Second low-noise amplifier; 107: Second bandpass filter; 108: Second 3dB attenuator; 109: Third low-noise amplifier; 110: Third bandpass filter; 111: First RF transmitting antenna; 112: First microprocessor; 201: Second RF receiving antenna; 202: Fourth low-noise amplifier; Noise amplifier, 203: Fourth bandpass filter, 204: Third 3dB attenuator, 205: Second phase shifter, 206: Fifth low-noise amplifier, 207: Fifth bandpass filter, 208: Fourth 3dB attenuator, 209: Sixth low-noise amplifier, 210: Sixth bandpass filter, 211: Fifth 3dB attenuator, 212: Seventh low-noise amplifier, 213: Seventh bandpass filter, 214: Sixth 3dB attenuator, 215: Eighth low-noise amplifier, 216: Eighth bandpass filter, 217: Second RF transmitting antenna, 218: Second microprocessor, 219: Digital-to-analog converter, 220: Operational amplifier. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Those skilled in the art should understand that these embodiments are merely used to explain the technical principles of this application and are not intended to limit the scope of protection of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0043] It should be noted that the terms "vertical direction," "horizontal direction," "+45° or -45° direction," "upper," "middle," "lower," and similar expressions are for illustrative purposes only and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0045] In the description of this application, "module" and "processor" can include hardware, software, or a combination of both. A module can include hardware circuitry, various suitable sensors, communication ports, memory, and can also include software components, such as program code, or a combination of software and hardware. A processor can be a central processing unit, microprocessor, image processor, digital signal processor, or any other suitable processor. The processor has data and / or signal processing capabilities. The processor can be implemented in software, in hardware, or a combination of both. Non-transitory computer-readable storage media includes any suitable medium capable of storing program code, such as magnetic disks, hard disks, optical disks, flash memory, read-only memory, random access memory, etc. The term "A and / or B" means all possible combinations of A and B, such as only A, only B, or A and B. The terms "at least one A or B" or "at least one of A and B" have a similar meaning to "A and / or B" and can include only A, only B, or A and B. The singular terms "a" or "this" can also include plural forms.

[0046] To address the technical problems of existing passive corner reflectors, such as complex installation and debugging, low measurement accuracy, and limited measurement range due to their structure and working principle, this application provides an active corner reflector and monitoring system, such as... Figure 1 As shown, the active corner reflector in this embodiment includes:

[0047] Receiver unit 11 is used to receive electromagnetic wave signals;

[0048] The first signal amplification unit 12 is used to amplify the power of the electromagnetic wave signal to obtain the first amplified signal;

[0049] Phase shifting unit 13 is used to adjust the phase of the first amplified signal to obtain a phase-shifted signal;

[0050] The second signal amplification unit 14 is used to amplify the phase-shifted signal to obtain a second amplified signal.

[0051] The transmitting unit 15 is used to transmit a second amplified signal, wherein the second amplified signal returns along the original path of the electromagnetic wave signal;

[0052] The receiving unit 11, the first signal amplification unit 12, the phase shifting unit 13, the second signal amplification unit 14, and the transmitting unit 15 are electrically connected in sequence.

[0053] To make the signal flow between units more stable, such as Figure 2 As shown, the active corner reflector in this embodiment further includes: a first attenuator 16; the first attenuator 16 is disposed between the first signal amplification unit 12 and the phase shifting unit 13; the first attenuator 16 is used to reduce the power of the first amplified signal to obtain an attenuated signal; the phase shifting unit 13 is used to adjust the phase of the attenuated signal to obtain a phase-shifted signal.

[0054] To more easily and effectively amplify the power of electromagnetic wave signals, the first signal amplification unit 12 in this embodiment includes: a first low-noise amplifier and a first filter; the input terminal of the first low-noise amplifier is electrically connected to the output terminal of the receiving unit 11, and the output terminal of the first low-noise amplifier is electrically connected to the input terminal of the first filter; the output terminal of the first filter is electrically connected to the input terminal of the first attenuator 16.

[0055] In this embodiment, the first filter is a bandpass filter to more effectively suppress out-of-band spurious signals, i.e., filter out interference signals and obtain an effective amplified signal, which is the aforementioned first amplified signal. The first amplified signal is output from the first filter to the input terminal of the phase shifting unit 13, where the phase shifting unit 13 performs subsequent phase adjustment.

[0056] To perform phase adjustment on the signal more accurately and efficiently, the phase shifting unit 13 in this embodiment includes a phase shifter and a control unit; the input terminal of the phase shifter is electrically connected to the output terminal of the first attenuator 16, and the output terminal of the phase shifter is electrically connected to the input terminal of the second signal amplification unit 14; the input terminal of the phase shifter is also electrically connected to the output terminal of the control unit; the control unit is used to output phase adjustment information to control the phase shifter to adjust the phase of the attenuated signal according to the phase adjustment information to obtain the phase-shifted signal.

[0057] In practical applications, the type of phase shifter can be selected according to actual needs. The phase shifter can be selected as a digital phase shifter or an analog phase shifter.

[0058] In this embodiment, the phase shifter is a digital phase shifter. That is, when the phase shifter is selected as a digital phase shifter, the control unit includes a first processor. The input terminal of the digital phase shifter is also electrically connected to the output terminal of the first processor. The phase adjustment information includes a phase adjustment amount. The first processor is used to output the phase adjustment amount to control the digital phase shifter to adjust the phase of the attenuation signal according to the phase adjustment amount to obtain the phase-shifted signal.

[0059] In this embodiment, when the phase shifter is a digital phase shifter, it can be directly controlled by a first processor outputting a digital signal. The first processor can be a first microprocessor (MCU). For example, the first MCU can calculate the phase shift of the signal based on the detection result of the received signal, and then calculate the phase value that needs to be compensated. The first MCU can output a 6-bit binary digital signal to control the digital phase shifter, so that it performs phase compensation / adjustment on the signal output by the first attenuator according to the calculated phase value that needs to be compensated, to obtain the phase-shifted signal, so that the phase-shifted signal can return along the original path of the received electromagnetic wave signal after subsequent amplification. That is, after the above digital phase shift operation, it can be guaranteed that the subsequent second amplified signal returns along the original path of the received electromagnetic wave signal.

[0060] In this embodiment, the phase shifter is an analog phase shifter. That is, when the phase shifter is selected as an analog phase shifter, the control unit includes: a second processor, a digital-to-analog converter, and an operational amplifier connected in sequence; the input terminal of the analog phase shifter is also electrically connected to the output terminal of the operational amplifier; the phase adjustment information includes a phase adjustment amount; the second processor is used to output the phase adjustment amount; the digital-to-analog converter is used to convert the phase adjustment amount into an analog signal; the operational amplifier is used to amplify the analog signal to obtain an amplified analog signal; the second processor is also used to control the analog phase shifter to adjust the phase of the attenuation signal according to the amplified analog signal to obtain a phase-shifted signal.

[0061] In this embodiment, when the phase shifter is an analog phase shifter, it can be controlled by converting the digital signal output by the second processor into an analog signal. The second processor can be a second microprocessor (MCU). For example, the second MCU can calculate the phase shift of the signal based on the detection result of the received signal, and then calculate the phase value that needs to be compensated. The second MCU can output a digital signal, which passes through a digital-to-analog converter and an operational amplifier in sequence to obtain an amplified analog signal. This amplified analog signal is a continuously changing analog voltage, which controls the analog phase shifter to perform phase compensation / adjustment on the signal output by the first attenuator according to the calculated phase value that needs to be compensated, thereby obtaining the phase-shifted signal. This ensures that the phase-shifted signal, after subsequent amplification, can return along the original path of the received electromagnetic wave signal. That is, after the above-mentioned analog phase shift operation, it can be guaranteed that the subsequent second amplified signal returns along the original path of the received electromagnetic wave signal.

[0062] It should be noted that in practical applications, when the target position on the surface of the object, i.e. the installation position of the active corner reflector, does not shift or deform, the first microprocessor or the second microprocessor calculates that the phase value to be compensated is 0. At this time, there is no need to compensate the signal of the input phase shifter, and the subsequent signal can still return along the original path of the received electromagnetic wave signal to ensure that the radar device that transmits the above electromagnetic wave signal can effectively receive the reflected signal.

[0063] In this embodiment, the second signal amplification unit 14 includes at least one first signal amplification unit 12; in the second signal amplification unit 14, when there are two or more first signal amplification units 12, each first signal amplification unit 12 is electrically connected in sequence.

[0064] In this embodiment, the second signal amplification unit 14 adopts the same circuit structure as the first signal amplification unit 12. In this way, while keeping the circuit structure simple, the signal processing and flow are more stable, thereby making the whole circuit more stable.

[0065] Furthermore, in order to make the signal flow between each unit more stable, a second attenuator is also provided between each first signal amplification unit 12; the second attenuator is used to reduce the amplified signal of each stage in the first signal amplification unit 12, so as to keep the circuit stable.

[0066] To achieve more precise signal attenuation, in this embodiment, the second attenuator has a π-type circuit topology, or a T-type circuit topology. Of course, other topologies can be chosen for the second attenuator depending on the specific application requirements; this embodiment does not impose any specific limitations on this.

[0067] In this embodiment, the first attenuator 16 and the second attenuator are of the same type to ensure the simplicity and stability of the circuit. The topology of the first attenuator 16 can also be a π-type circuit or a T-type circuit to achieve more precise signal attenuation. Of course, depending on the actual application requirements, other topologies can be selected for the first attenuator 16, and this embodiment does not impose specific limitations on this.

[0068] In order to keep the circuit structure simple while effectively receiving radio frequency signals, in this embodiment, the receiving unit 11 is a radio frequency receiving antenna and the transmitting unit 15 is a radio frequency transmitting antenna.

[0069] In this embodiment, the electromagnetic wave signal is a radio frequency signal transmitted by the radar device. Furthermore, to enable the receiving unit 11 to receive the radio frequency signal more effectively, the radio frequency signal transmitted by the radar device is a circularly polarized radio frequency signal.

[0070] Based on the functions of each unit and the signal flow between them, this application can effectively overcome the technical problems of existing passive corner reflectors, which are limited by their structure and working principle, resulting in complex installation and debugging of the monitoring system, low measurement accuracy, and limited measurement range.

[0071] The following is passed Figure 3 and Figure 4 This will further illustrate the specific circuit structure and signal flow of this embodiment.

[0072] Figure 3 This is a circuit diagram of an active corner reflector provided in an embodiment of this application. Figure 3 As shown, an active corner reflector 100 includes a transceiver antenna, a low-noise amplifier (LNA), and a first phase shifter. Specifically, it includes a first radio frequency receiving antenna 101, a first low-noise amplifier 102, a first bandpass filter 103, a first 3dB attenuator 104, a first phase shifter 105, a second low-noise amplifier 106, a second bandpass filter 107, a second 3dB attenuator 108, a third low-noise amplifier 109, a third bandpass filter 110, a first radio frequency transmitting antenna 111, and a first microprocessor 112, connected in sequence.

[0073] In practical applications, the first phase shifter 105 is connected to the first microprocessor 112. Preferably, the first phase shifter is a digital phase shifter, and the preferred model is TGP2105-SM. The phase shift amount of the first phase shifter is controlled by 6 bits.

[0074] The first radio frequency receiving antenna 101 receives the circularly polarized radio frequency signal transmitted by the Doppler radar device. The received radio frequency signal is then amplified by the first low-noise amplifier 102 to obtain a signal with amplified power. This signal then passes through a first bandpass filter 103 to suppress out-of-band spurious signals, resulting in a first filtered radio frequency signal. The first filtered signal is then amplitude-adjusted by a first 3dB attenuator 104, resulting in a first amplitude-adjusted radio frequency signal. This amplitude-adjusted signal is then phase-adjusted by a first phase shifter 105 to ensure that subsequent signals transmitted by the first radio frequency transmitting antenna 111 can return along the same path as the circularly polarized radio frequency signal. Finally, the radio frequency signal adjusted by the first phase shifter 105 is amplified by a second low-noise amplifier 106, resulting in a second stage of amplification. The signal is first amplified to a second level (2dB). Then, it passes through a second bandpass filter 107 to suppress spurious signals generated during the second amplification process, resulting in a second filtered RF signal. This second filtered RF signal undergoes a second amplitude adjustment via a second 3dB attenuator 108, yielding a second amplitude-adjusted RF signal. This second amplitude-adjusted RF signal then passes through a third low-noise amplifier 109 for a third amplification, resulting in a third-level amplified RF signal. A third bandpass filter 110 further suppresses spurious signals generated during the third-level amplification process to improve the RF signal's directivity. Finally, the signal is transmitted back to the Doppler radar device via the first RF transmitting antenna 111. The Doppler radar device determines the deformation or displacement of the corner reflector mounting surface based on the phase shift between the received and transmitted RF signals. The Doppler radar device can also generate a warning signal when the deformation or displacement reaches a warning threshold.

[0075] In practical applications, by selecting the above-mentioned components, the above circuit, i.e. the active corner reflector, can be made to work in the target frequency band.

[0076] In this embodiment, the first low-noise amplifier 102, the second low-noise amplifier 106, and the third low-noise amplifier 109 have the same specifications and model, and can be selected as PMA-183PLN+, each achieving a gain of 29.7dB.

[0077] In this embodiment, since the signal processing of the entire active corner reflector does not involve the adjustment of the radio frequency signal frequency, the first bandpass filter 103, the second bandpass filter 107, and the third bandpass filter 110 can also use the same specifications and be set with the same passband frequency. For example, the model of the first bandpass filter 103, the second bandpass filter 107, and the third bandpass filter 110 can be BFHKI-1572+.

[0078] In this embodiment, the first 3dB attenuator 104 and the second 3dB attenuator 108 can be π-type circuits or T-type circuits. The first 3dB attenuator 104 and the second 3dB attenuator 108 can be the same type of circuit or different types of circuits.

[0079] This embodiment, through specific device selection, enables the active corner reflector to operate at 15.7~17.2GHz.

[0080] After testing and verification, the active corner reflector provided in this embodiment can achieve radio frequency signal gain feedback of more than 60dB, effectively improving the signal identification accuracy of the Doppler radar device, and thus improving the monitoring accuracy of the entire monitoring system.

[0081] Figure 4 This is another circuit structure diagram of an active corner reflector provided in an embodiment of this application. Figure 3 Further improvements were made based on the illustrated embodiments. For example... Figure 4 As shown, the active corner reflector provided in this embodiment includes a transceiver antenna, a low-noise amplifier (LNA), and a second phase shifter.

[0082] Specifically, the active corner reflector 200 includes, in sequence, a second radio frequency receiving antenna 201, a fourth low-noise amplifier 202, a fourth bandpass filter 203, a third 3dB attenuator 204, a second phase shifter 205, a fifth low-noise amplifier 206, a fifth bandpass filter 207, a fourth 3dB attenuator 208, a sixth low-noise amplifier 209, a sixth bandpass filter 210, a fifth 3dB attenuator 211, a seventh low-noise amplifier 212, a seventh bandpass filter 213, a sixth 3dB attenuator 214, an eighth low-noise amplifier 215, an eighth bandpass filter 216, a second radio frequency transmitting antenna 217, a second microprocessor 218, a digital-to-analog converter 219, and an operational amplifier 220, all electrically connected in sequence.

[0083] In this embodiment, the second phase shifter 205 is an analog phase shifter, which can be model SIP017SP4, and the operating frequency of this model is 18 to 26.5 GHz.

[0084] In this embodiment, the second phase shifter 205 is also connected to an operational amplifier 220, which is connected to a digital-to-analog converter 219, which is connected to a second microprocessor 218. The second microprocessor 218 sends a digital phase-shift sequence to the digital-to-analog converter 219, which converts the digital phase-shift sequence into an analog phase-shift signal. The analog phase-shift signal is then transmitted to the second phase shifter 205 via the operational amplifier 220 after signal amplitude adjustment.

[0085] In this embodiment, the signal processing before the second phase shifter 205 includes a first-stage amplification and filtering followed by 3dB attenuation, while the signal processing after the second phase shifter 205 includes a fourth-stage amplification and filtering followed by a third-stage 3dB attenuation. The specific connection relationships are as follows: Figure 4 As shown.

[0086] In this embodiment, all the low-noise amplifiers (LNAs) mentioned above have the same specifications and model number, such as HMC751LC4, each achieving a gain of 19dB.

[0087] In this embodiment, since the signal processing of the entire active corner reflector does not involve the adjustment of the radio frequency signal frequency, each bandpass filter (BPF) can use the same specifications and be set with the same passband frequency. For example, the model of the bandpass filter (BPF) can be BFHK-2492+, and the passband frequency can be set to 22-28 GHz.

[0088] In this embodiment, each of the aforementioned 3dB attenuators can be a π-type circuit or a T-type circuit. Each 3dB attenuator can use the same type of circuit or different types of circuits. Through specific component selection, the active corner reflector can operate at 24GHz.

[0089] After testing and verification, the active corner reflector provided in this embodiment can achieve a radio frequency signal gain feedback of nearly 60dB, effectively improving the signal identification accuracy of the Doppler radar device, and thus improving the monitoring accuracy of the entire monitoring system.

[0090] In practical applications, for RF signal feedback requiring higher gain, selective adjustment can be made in... Figure 3 or Figure 4 The phase shifter shown is implemented by connecting multiple stages of amplifier and filter circuits in series.

[0091] The technical solution provided in this application, by setting up a receiving unit 11, a first signal amplification unit 12, a phase shifting unit 13, a second signal amplification unit 14, and a transmitting unit 15, enables the active corner reflector to amplify the power and adjust the phase of the received electromagnetic wave signal, and to return the amplified signal along the original path of the electromagnetic wave signal. This effectively overcomes the technical problems of passive corner reflectors, which, due to their structure and working principle, can only passively reflect electromagnetic wave signals, leading to complex installation and debugging of the monitoring system, low measurement accuracy, and limited measurement range. The technical solution provided in this application simplifies the installation of the monitoring system and greatly improves the system's measurement accuracy and range.

[0092] By adopting the active corner reflector provided in this application, the problems of limited monitoring range, cumbersome installation and debugging, inability to automatically aim, and inability to monitor multiple points that exist in existing passive radar corner reflectors are avoided; at the same time, the active corner reflector provided in this application has the characteristics of simple structure, low cost and high reliability.

[0093] Furthermore, this application also provides a monitoring system, including: a radar device, and an active corner reflector of any of the technical solutions provided in the above embodiments; the active corner reflector is installed at a target position on the surface of the object being measured; the radar device is used to perform the following operations:

[0094] S1, send electromagnetic wave signals to the target location;

[0095] S2, receives the second amplified signal returned by the active corner reflector;

[0096] S3, based on the second amplified signal, monitor the displacement and / or deformation of the target position.

[0097] In this embodiment, the radar device is used to emit electromagnetic waves and receive electromagnetic waves returned by the active corner reflector. The second amplified signal emitted by the active corner reflector can only be effectively received by the radar device if it returns along the original path of the electromagnetic wave signal emitted by the radar device; otherwise, the radar device will lose the monitoring signal.

[0098] The objects being measured can be infrastructure such as bridges, tunnels, and mines that are susceptible to collapse due to geological disasters. After receiving the returned second amplified signal, the radar device determines, based on the phase adjustment of the second amplified signal, whether the target position on the surface of the object has shifted or deformed, and to what extent. When the radar device detects that the shift or deformation exceeds a warning threshold, it generates a warning signal to notify relevant personnel to take timely action, thereby effectively preventing collapse disasters.

[0099] In this embodiment, the radar device is preferably a Doppler radar device to monitor the object being measured more accurately.

[0100] The technical solution provided in this application, by setting up a receiving unit, a first signal amplification unit, a phase shifting unit, a second signal amplification unit, and a transmitting unit, enables the active corner reflector to amplify the power and adjust the phase of the received electromagnetic wave signal, and to return the amplified signal along the original path of the electromagnetic wave signal. This effectively overcomes the technical problems of passive corner reflectors, which, due to their structure and working principle, can only passively reflect electromagnetic wave signals, leading to complex installation and debugging of the monitoring system, low measurement accuracy, and limited measurement range. The technical solution provided in this application simplifies the installation of the monitoring system and greatly improves the system's measurement accuracy and range.

[0101] It should be noted that although the steps in the above embodiments are described in a specific order, those skilled in the art will understand that in order to achieve the effect of this application, different steps do not necessarily have to be executed in such an order. They can be executed simultaneously (in parallel) or in other orders, and these variations are all within the scope of protection of this application.

[0102] The preferred embodiments of this application have been described above in conjunction with the accompanying drawings. However, it should be noted that the above embodiments are merely illustrative of the technical solutions of this invention and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to depart from the spirit and scope of the technical solutions of the embodiments of this invention.

Claims

1. An active corner reflector, characterized in that, include: The receiving unit is used to receive electromagnetic wave signals; The first signal amplification unit is used to amplify the power of the electromagnetic wave signal to obtain a first amplified signal; A phase-shifting unit is used to adjust the phase of the first amplified signal to obtain a phase-shifted signal; The second signal amplification unit is used to amplify the power of the phase-shifted signal to obtain a second amplified signal; A transmitting unit is used to transmit the second amplified signal, wherein the second amplified signal returns along the original path of the electromagnetic wave signal; The receiving unit, the first signal amplification unit, the phase shifting unit, the second signal amplification unit, and the transmitting unit are electrically connected in sequence.

2. The active corner reflector according to claim 1, characterized in that, Also includes: A first attenuator; the first attenuator is disposed between the first signal amplification unit and the phase shifting unit; The first attenuator is used to reduce the power of the first amplified signal to obtain an attenuated signal; The phase-shifting unit is used to adjust the phase of the attenuated signal to obtain the phase-shifted signal.

3. The active corner reflector according to claim 2, characterized in that, The first signal amplification unit includes: a first low-noise amplifier and a first filter; the input terminal of the first low-noise amplifier is electrically connected to the output terminal of the receiving unit, and the output terminal of the first low-noise amplifier is electrically connected to the input terminal of the first filter; the output terminal of the first filter is electrically connected to the input terminal of the first attenuator.

4. The active corner reflector according to claim 2, characterized in that, The phase shifting unit includes a phase shifter and a control unit; the input terminal of the phase shifter is electrically connected to the output terminal of the first attenuator, and the output terminal of the phase shifter is electrically connected to the input terminal of the second signal amplification unit; the input terminal of the phase shifter is also electrically connected to the output terminal of the control unit. The control unit is used to output phase adjustment information to control the phase shifter to adjust the phase of the attenuation signal according to the phase adjustment information, so as to obtain the phase-shifted signal.

5. The active corner reflector according to claim 4, characterized in that, The phase shifter is a digital phase shifter; the control unit includes a first processor; the input terminal of the digital phase shifter is also electrically connected to the output terminal of the first processor; the phase adjustment information includes a phase adjustment amount; The first processor is used to output the phase adjustment amount to control the digital phase shifter to adjust the phase of the attenuation signal according to the phase adjustment amount, so as to obtain the phase-shifted signal.

6. The active corner reflector according to claim 4, characterized in that, The phase shifter is an analog phase shifter; the control unit includes: a second processor, a digital-to-analog converter, and an operational amplifier connected in sequence; the input terminal of the analog phase shifter is also electrically connected to the output terminal of the operational amplifier; the phase adjustment information includes the phase adjustment amount; The second processor is used to output the phase adjustment amount; The digital-to-analog converter is used to convert the phase adjustment amount into an analog signal; The operational amplifier is used to amplify the analog signal to obtain an amplified analog signal; The second processor is also used to control the analog phase shifter to adjust the phase of the attenuated signal according to the amplified analog signal, so as to obtain the phase-shifted signal.

7. The active corner reflector according to claim 1, characterized in that, The second signal amplification unit includes at least one first signal amplification unit; in the second signal amplification unit, when there are two or more first signal amplification units, each first signal amplification unit is electrically connected in sequence.

8. The active corner reflector according to claim 7, characterized in that, A second attenuator is also provided between each of the first signal amplification units; the topology of the second attenuator is a π-type circuit, or the topology of the second attenuator is a T-type circuit.

9. The active corner reflector according to claim 1, characterized in that, The receiving unit is a radio frequency receiving antenna; the transmitting unit is a radio frequency transmitting antenna; and the electromagnetic wave signal is a circularly polarized radio frequency signal.

10. A monitoring system, characterized in that, include: A radar device, and an active corner reflector as described in any one of claims 1-9; the active corner reflector is mounted at a target location on the surface of the object being measured; the radar device is configured to perform the following operations: The electromagnetic wave signal is sent to the target location; Receive the second amplified signal returned by the active corner reflector; The displacement and / or deformation of the target location are monitored based on the second amplified signal.

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