Target micro-motion detection system and method based on Rydberg atoms

Abstract

The invention relates to the field of target micro-motion detection, and provides a Rydberg atom-based target micro-motion detection system and method, and the system comprises a microwave generation device, a Rydberg atom sensor, a photoelectric detector, and a signal collection and processing module. The microwave generating device comprises a local oscillation microwave source for generating a local oscillation microwave field and a signal microwave source for generating a signal microwave field; the signal microwave field penetrates through the Rydberg atom sensor and is emitted to a to-be-detected target, an echo signal field of the to-be-detected target returns to the Rydberg atom sensor and is subjected to three-field frequency mixing with the local oscillation microwave field and the signal microwave field, and a target micro-motion signal carrying frequency mixing information is obtained; the photoelectric detector is used for detecting the target micro-motion signal carrying the frequency mixing information and processing the target micro-motion signal to obtain an electric signal, and the electric signal is input to the signal acquisition and processing module to complete target micro-motion detection. Target micro-motion detection is carried out based on the Rydberg atom sensor, and the detection capability of an existing radar system on weak and small targets can be improved.

Description

Technical Field

[0001] The present invention relates to the field of target micro-motion detection, and in particular to a target micro-motion detection system and method based on Rydberg atoms. Background Art

[0002] Micromotion refers to minute movements of a target or its components, such as vibration, rotation, and acceleration, in addition to the translational motion of its center of mass. These movements are common in real life, such as the rolling of a vehicle's tires, the swinging of a person's arms when walking, and the rotation of helicopter rotors. Micromotion modulates the target's radar return signal, generating Doppler sidebands related to the target's main body, known as the micro-Doppler effect. Target micromotion and its micro-Doppler effect are unique manifestations of the target's physical properties, reflecting its unique structural information and motion characteristics. Therefore, they have attracted widespread attention in areas such as weak target detection, radar target recognition, and classification.

[0003] For detecting target micro-motion, the main detection methods currently include traditional microwave radar detection and lidar detection (Chinese patent CN114397670A, "Lidar system and measurement method for micro-Doppler measurement of high-speed moving targets"; Chinese patent CN117169913A, "A system and method for detecting target micro-motion based on pulsed laser signals"). However, in actual applications, these methods have problems such as detection sensitivity being limited by thermal noise or complex system structure, making it difficult to achieve the requirements of high-precision and high-sensitivity target micro-motion detection. Summary of the Invention

[0004] Current methods for detecting target micro-motions suffer from limitations in practical applications, such as limited sensitivity due to thermal noise or complex system structures, making it difficult to achieve high-precision and high-sensitivity target micro-motion detection. This invention provides a target micro-motion detection system and method based on Rydberg atoms to enhance the detection capabilities of existing radar systems for small and weak targets.

[0005] In a first aspect, the present invention provides a target micro-motion detection system based on Rydberg atoms, comprising a microwave generating device, a Rydberg atom sensor, a photoelectric detector, and a signal acquisition and processing module;

[0006] The microwave generating device includes a local oscillator microwave source for generating a local oscillator microwave field and a signal microwave source for generating a signal microwave field; the signal microwave field is transmitted toward the target to be detected through the Rydberg atomic sensor, and the echo signal field of the target to be detected returns to the Rydberg atomic sensor and undergoes three-field mixing with the local oscillator microwave field and the signal microwave field to obtain a target micro-motion signal carrying mixing information;

[0007] The photoelectric detector is used to detect the target micro-motion signal carrying the mixing information and obtain an electrical signal after processing. The electrical signal is input into the signal acquisition and processing module to complete the target micro-motion detection.

[0008] In some embodiments, the signal microwave source plays two roles:

[0009] First, it acts as a signal transmitter to generate a signal microwave field for target detection;

[0010] The second is to act as a frequency shifter, mixing the local oscillator microwave field and then shifting the ideal zero frequency.

[0011] In some embodiments, the Rydberg atom sensor includes a laser, a cesium atomic vapor pool, and a Rydberg atom laser optical path module; the laser and the Rydberg atom laser optical path module are used to generate detection light and coupling light that are transmitted in opposite directions and in a collinear manner, and act on the cesium atomic vapor pool to form a stepped three-level Rydberg EIT system.

[0012] In some embodiments, the Rydberg atom sensor serves two functions:

[0013] First, it acts as a signal receiving device to receive the target echo signal field;

[0014] The second is to act as a mixer to perform three-field mixing of the local oscillator microwave field, signal microwave field and target echo signal field to achieve superheterodyne detection.

[0015] In some embodiments, the signal acquisition and processing module includes a digital sampling oscilloscope and a spectrum analyzer;

[0016] The digital sampling oscilloscope is used to collect the electrical signal output by the photoelectric detector;

[0017] The spectrum analyzer is used to process and analyze the collected electrical signal to obtain the signal spectrum distribution containing target micro-motion information.

[0018] In a second aspect, the present invention provides a method for detecting target micro-motion based on Rydberg atoms, which is implemented based on the above-mentioned target micro-motion detection system based on Rydberg atoms;

[0019] The method comprises:

[0020] Step 1: using two microwave sources to provide a local oscillator microwave field and a signal microwave field respectively;

[0021] Step 2: The signal microwave field passes vertically through the Rydberg quantum sensor and is emitted toward the target. After being scattered by the moving target, it forms an echo signal field that carries the target micro-motion characteristic information. The Rydberg quantum sensor receives the echo signal field and mixes it with the local microwave field and the signal microwave field to form a three-field mixing to obtain the target micro-motion signal that carries the mixing information.

[0022] Step 3: using a photoelectric detector to collect the target micro-motion signal carrying the mixing information and convert it into an electrical signal;

[0023] Step 4: Input the electrical signal into the signal acquisition and processing module for data processing to extract signal features, perform time-frequency domain analysis on the signal features, output the signal spectrum distribution containing target micro-motion information, and complete the micro-motion detection of the target to be detected.

[0024] In some embodiments, in step 1, there is a fixed frequency difference between the local oscillator microwave field and the signal microwave field, the frequency of the local oscillator microwave field can drive the resonant transition between atomic Rydberg states, and the local oscillator microwave field and the signal microwave field form a Rydberg atom superheterodyne detection system with the Rydberg atom sensor.

[0025] In some embodiments, the three-field mixing includes a difference frequency signal between the local oscillator microwave field and the signal microwave field, a difference frequency signal between the local oscillator microwave field and the echo signal field, and a difference frequency signal between the signal microwave field and the echo signal field.

[0026] In some embodiments, the data processing process includes removing the DC component of the target micro-motion signal and extracting the time domain signal envelope feature.

[0027] In some embodiments, the time-frequency domain analysis method includes short-time Fourier transform, wavelet transform, Wigner-Ville distribution, Cohen-type time-frequency distribution, or Affine-type time-frequency distribution.

[0028] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0029] The present invention uses a Rydberg atomic sensor to detect target micro-motions, which can enhance the existing radar system's ability to detect small and weak targets. It has the advantages of a simple system structure, a novel method, high detection sensitivity, high detection accuracy, and ease of miniaturization and integration. It can be applied to fields such as radar speed measurement and micro-motion feature recognition. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic structural diagram of a target micro-motion detection system based on Rydberg atoms provided in an embodiment of the present invention.

[0031] Figure 2 A flow chart of a target micro-motion detection method based on Rydberg atoms provided in an embodiment of the present invention.

[0032] Figure 3 FIG. 4 is a distribution diagram of a signal spectrum containing target micro-motion information in an embodiment of the present invention. DETAILED DESCRIPTION

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0035] Example

[0036] like Figure 1 As shown, an embodiment of the present invention provides a target micro-motion detection system based on Rydberg atoms, including a microwave generating device, a Rydberg atom sensor, a photoelectric detector, and a signal acquisition and processing module;

[0037] The microwave generating device includes a local oscillator microwave source for generating a local oscillator microwave field and a signal microwave source for generating a signal microwave field; the signal microwave field is transmitted toward the target to be detected through the Rydberg atom sensor, and the echo signal field of the target to be detected returns to the Rydberg atom sensor and undergoes three-field mixing with the local oscillator microwave field and the signal microwave field to obtain a target micro-motion signal (optical signal) carrying the mixing information;

[0038] The photoelectric detector is used to detect the target micro-motion signal carrying the mixing information and obtain an electrical signal after processing. The electrical signal is input into the signal acquisition and processing module to complete the target micro-motion detection.

[0039] In this embodiment, the signal microwave source in the microwave generating device preferably plays two roles:

[0040] First, it acts as a signal transmitter to generate a signal microwave field for target detection;

[0041] Secondly, as a frequency shifter, it mixes the local oscillator microwave field and then moves the ideal zero frequency, thereby preventing the Doppler frequency shift caused by the target micro-motion from being submerged in the low-frequency noise and avoiding noise interference near the zero frequency.

[0042] In this embodiment, preferably, the Rydberg atom sensor includes a laser, a cesium atomic vapor pool and a Rydberg atom laser optical path module; the laser and the Rydberg atom laser optical path module are used to generate detection light and coupling light that are transmitted in opposite collinear directions and act on the cesium atomic vapor pool to form a stepped three-level Rydberg EIT system.

[0043] In this embodiment, the Rydberg atomic sensor preferably plays two roles:

[0044] First, it acts as a signal receiving device to receive the target echo signal field;

[0045] The second is to act as a mixer to perform three-field mixing of the local oscillator microwave field, signal microwave field and target echo signal field to achieve superheterodyne detection.

[0046] In this embodiment, preferably, the signal acquisition and processing module includes a digital sampling oscilloscope and a spectrum analyzer;

[0047] The digital sampling oscilloscope is used to collect the electrical signal output by the photoelectric detector;

[0048] The spectrum analyzer is used to process and analyze the collected electrical signal to obtain the signal spectrum distribution containing target micro-motion information.

[0049] like Figure 2 As shown, the present invention also provides a method for detecting target micro-motion based on Rydberg atoms, which is implemented by the above system. The specific implementation steps include:

[0050] Step 1: Use two microwave sources to provide a local oscillator microwave field and a signal microwave field respectively.

[0051] There is a fixed frequency difference between the local oscillator microwave field and the signal microwave field. The frequency of the local oscillator microwave field can drive the resonant transition between atomic Rydberg states. The local oscillator microwave field, the signal microwave field and the Rydberg atom sensor form a Rydberg atom superheterodyne detection system.

[0052] Step 2: The signal microwave field passes vertically through the Rydberg quantum sensor and is emitted toward the target. After being scattered by the moving target, it forms an echo signal field that carries the target micro-motion characteristic information. The Rydberg quantum sensor receives the echo signal field and mixes it with the local microwave field and the signal microwave field to form a three-field mixing to obtain the target micro-motion signal that carries the mixing information.

[0053] The three-field mixing includes the difference frequency signal between the local oscillator microwave field and the signal microwave field, the difference frequency signal between the local oscillator microwave field and the echo signal field, and the difference frequency signal between the signal microwave field and the echo signal field.

[0054] Step 3: Use a photoelectric detector to collect the target micro-motion signal carrying the mixing information and convert it into an electrical signal.

[0055] Step 4: Input the electrical signal into the signal acquisition and processing module for data processing to extract signal features, and perform time-frequency domain analysis on the signal features to output the signal spectrum distribution containing target micro-motion information, such as Figure 3 As shown, the micro-motion detection of the target to be detected is completed.

[0056] It can be seen from this that the present invention utilizes the characteristics of Rydberg atoms being extremely sensitive to changes in external field microwaves and the Rydberg atom sensor having high-precision and high-sensitivity detection capabilities, and can achieve high-sensitivity and high-precision detection of target micro-motion signals (including physical quantities such as frequency, field strength, and phase). Among them, on the basis of constructing a Rydberg atom sensor, the present invention adopts two microwave sources to respectively provide a local oscillator microwave field and a signal microwave field, and transmits the signal microwave field vertically through the quantum sensor to the target to be detected. The local oscillator microwave field is mixed with the signal microwave field and the target echo signal field at the Rydberg atom sensor, and the photoelectric detector is used to collect the mixed target micro-motion signal, and the target micro-motion detection result is output after signal processing, thereby achieving high-sensitivity detection of target micro-motion information. Compared with traditional methods, the present invention can improve the detection capability of existing radar systems for weak targets, and has the advantages of simple system structure, novel invention method, high detection sensitivity, and easy miniaturization and integration.

[0057] In this embodiment, preferably, the data processing process includes removing the DC component of the target micro-motion signal and extracting the envelope features of the time domain signal.

[0058] In this embodiment, preferably, the time-frequency domain analysis method includes short-time Fourier transform, wavelet transform, Wigner-Ville distribution, Cohen-type time-frequency distribution or Affine-type time-frequency distribution.

[0059] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A target micro-motion detection system based on Rydberg atoms, characterized in that: It includes microwave generator, Rydberg atomic sensor, photoelectric detector, signal acquisition and processing module; The microwave generating device includes a local oscillator microwave source for generating a local oscillator microwave field and a signal microwave source for generating a signal microwave field; the signal microwave field is transmitted toward the target to be detected through the Rydberg atomic sensor, and the echo signal field of the target to be detected returns to the Rydberg atomic sensor and undergoes three-field mixing with the local oscillator microwave field and the signal microwave field to obtain a target micro-motion signal carrying mixing information; The photoelectric detector is used to detect the target micro-motion signal carrying the mixing information and obtain an electrical signal after processing. The electrical signal is input into the signal acquisition and processing module to complete the target micro-motion detection.

2. The target micro-motion detection system based on Rydberg atoms according to claim 1, characterized in that: The signal microwave source plays two roles: First, it acts as a signal transmitter to generate a signal microwave field for target detection; The second is to act as a frequency shifter, mixing the local oscillator microwave field and then shifting the ideal zero frequency.

3. The target micro-motion detection system based on Rydberg atoms according to claim 1, characterized in that: The Rydberg atom sensor includes a laser, a cesium atomic vapor pool and a Rydberg atom laser optical path module; the laser and the Rydberg atom laser optical path module are used to generate detection light and coupling light that are transmitted in opposite collinear directions and act on the cesium atomic vapor pool to form a stepped three-level Rydberg EIT system.

4. The target micro-motion detection system based on Rydberg atoms according to claim 1, characterized in that: The Rydberg atomic sensor serves two purposes: First, it acts as a signal receiving device to receive the target echo signal field; The second is to act as a mixer to perform three-field mixing of the local oscillator microwave field, signal microwave field and target echo signal field to achieve superheterodyne detection.

5. The target micro-motion detection system based on Rydberg atoms according to claim 1, characterized in that: The signal acquisition and processing module includes a digital sampling oscilloscope and a spectrum analyzer; The digital sampling oscilloscope is used to collect the electrical signal output by the photoelectric detector; The spectrum analyzer is used to process and analyze the collected electrical signal to obtain the signal spectrum distribution containing target micro-motion information.

6. A method for detecting target micro-motion based on Rydberg atoms, characterized in that: Implementation based on the target micro-motion detection system based on Rydberg atoms as described in any one of claims 1 to 5; The method comprises: Step 1: using two microwave sources to provide a local oscillator microwave field and a signal microwave field respectively; Step 2: The signal microwave field passes vertically through the Rydberg quantum sensor and is emitted toward the target. After being scattered by the moving target, it forms an echo signal field that carries the target micro-motion characteristic information. The Rydberg quantum sensor receives the echo signal field and mixes it with the local microwave field and the signal microwave field to form a three-field mixing to obtain the target micro-motion signal that carries the mixing information. Step 3: using a photoelectric detector to collect the target micro-motion signal carrying the mixing information and convert it into an electrical signal; Step 4: Input the electrical signal into the signal acquisition and processing module for data processing to extract signal features, perform time-frequency domain analysis on the signal features, output the signal spectrum distribution containing target micro-motion information, and complete the micro-motion detection of the target to be detected.

7. The target micro-motion detection method based on Rydberg atoms according to claim 6, characterized in that: In step 1, there is a fixed frequency difference between the local oscillator microwave field and the signal microwave field. The frequency of the local oscillator microwave field can drive the resonant transition between atomic Rydberg states. The local oscillator microwave field, the signal microwave field and the Rydberg atom sensor form a Rydberg atom superheterodyne detection system.

8. The target micro-motion detection method based on Rydberg atoms according to claim 6, characterized in that: The three-field mixing includes the difference frequency signal between the local oscillator microwave field and the signal microwave field, the difference frequency signal between the local oscillator microwave field and the echo signal field, and the difference frequency signal between the signal microwave field and the echo signal field.

9. The target micro-motion detection method based on Rydberg atoms according to claim 6, characterized in that: The data processing process includes removing the DC component of the target micro-motion signal and extracting the envelope feature of the time domain signal.

10. The target micro-motion detection method based on Rydberg atoms according to claim 6, characterized in that: The time-frequency domain analysis method includes short-time Fourier transform, wavelet transform, Wigner-Ville distribution, Cohen-type time-frequency distribution or Affine-type time-frequency distribution.

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