Cross-band microwave target tracking detection device and method

Abstract

The invention belongs to the technical field of quantum precision measurement, and discloses a cross-band microwave target tracking detection device and method. The device comprises a light source assembly, an atomic array probe, an antenna assembly and a signal acquisition and processing assembly, the light source assembly is used for providing a plurality of detection pump light combinations for the atomic array probe; the antenna assembly comprises a Cassegrain antenna, a signal generator and an electronic power divider, the atomic array probe comprises surface waveguides and a plurality of linearly arranged atomic gas chambers, the surface waveguides are arranged on the surfaces of the atomic gas chambers, and the signal acquisition and processing assembly is used for receiving probe light returned by the atomic gas chambers; according to the invention, the frequency band of microwave target measurement is expanded through the cross-band measurement of the plurality of atomic gas chambers, and the device has the advantages of high sensitivity, large frequency band range, high precision, capability of omnibearing tracking measurement and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of quantum precision measurement, and in particular relates to a cross-band microwave target tracking and detection device and method. Background Art

[0002] Traditional classical wireless measurement systems mainly rely on superheterodyne receivers based on metal antennas and electronic circuits. After years of development, their measurement sensitivity has reached its limit and cannot be tracked in real time, making it difficult to achieve cross-band measurements with higher sensitivity, such as high-precision measurement, detection of space signals, and perception of weak electric field signals. The Rydberg microwave quantum sensor, however, has an extreme sensitivity limited by quantum noise, which is several orders of magnitude smaller than thermal noise. It can be used to achieve ultra-high sensitivity measurements, provide an absolute standard for precise measurement science, and achieve the perception of weak signals, which greatly promotes the development of scientific research.

[0003] In addition, the current classic wireless measurement system is limited by the bandwidth of the classic microwave antenna. To measure cross-band microwave signals, it is necessary to carry multiple aperture antennas that match the wavelength of the microwave being measured, which makes the measurement device more complicated and the measurement sensitivity has reached its upper limit. The wavelength of the cross-band microwave signal has position changes, and the antenna needs to be tracked in real time. Although the Rydberg microwave quantum sensor has high sensitivity, it is limited by the characteristics of the atomic energy level. The microwave band range it measures is single, making it difficult to achieve cross-band microwave target measurement and tracking. Therefore, it is necessary to design a cross-band microwave target tracking and detection device to solve the above problems. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes a cross-band microwave target tracking and detection device and method to achieve high-sensitivity measurement of cross-band microwave targets.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a cross-band microwave target tracking and detection device, comprising: a light source component, an atomic array probe, an antenna component and a signal acquisition and processing component;

[0006] The light source assembly is used to provide a plurality of detection pump light combinations to the atomic array probe; the detection pump light combinations include a detection light beam and a pump light beam, the detection light wavelengths in each detection pump light combination are the same, and the pump light wavelengths are different, and are used to excite different Rydberg states of atoms;

[0007] The antenna assembly comprises a Cassegrain antenna, a signal generator and an electronic power divider, wherein the Cassegrain antenna is used to receive a microwave signal sent by a microwave target, the signal generator is used to generate a local oscillator microwave signal, and the electronic power divider is used to combine the microwave signal sent by the microwave target and the local oscillator microwave signal and then send the combined signal to the atomic array probe;

[0008] The atomic array probe comprises a surface waveguide and a plurality of linearly arranged atomic gas chambers, wherein the surface waveguide is arranged on the surface of each of the atomic gas chambers; a microwave transmission interface is arranged on the atomic gas chamber at the head end, and the microwave transmission interface is used to transmit the microwave signal output by the electronic power divider into each atomic gas chamber; each detection pump light combination output by the light source component corresponds to an atomic gas chamber; each of the atomic gas chambers is respectively provided with a light guide device, and the light guide device is used to reversely incident the corresponding detection pump light combination into the atomic gas chamber along the microwave emission direction, and is also used to make the detection light in the detection pump light combination return along the original path and be received by the signal acquisition and processing component;

[0009] The signal acquisition and processing component is used to receive the detection light returned by each atomic gas chamber and realize microwave measurement according to the intensity of the detection light.

[0010] The light source assembly includes a detection laser, a pump laser, a first beam splitter, a second beam splitter, multiple AOMs, multiple dichroic mirrors, and multiple PBS prisms. The detection light output by the detection laser is divided into multiple beams by the first beam splitter, and each beam of detection light is incident on a dichroic mirror. The pump light output by the pump laser is divided into multiple beams by the second beam splitter, and each beam of pump light is incident on a dichroic mirror after being frequency-shifted by an AOM. The dichroic mirror is used to combine the corresponding detection light and pump light to form a detection pump light combination and send it to the PBS prism. The PBS prism is used to send the detection pump light combination to the corresponding atomic gas chamber via an optical fiber.

[0011] There are four atomic gas chambers. The pump light output by the pump laser is divided into four beams by the second beam splitter. The wavelengths of the pump light after passing through each AOM are 508.660nm, 508.718nm, 508.903nm and 508.678nm respectively. The frequency of the detection light output by the detection laser is 852nm.

[0012] The light-guiding device comprises: a first optical fiber coupler, a right-angle reflection prism, a quarter-wave plate, a lens and a zero-degree reflection mirror. The right-angle reflection prism is arranged at the end of the atomic gas chamber. The detection pump light combination is transmitted to the first optical fiber coupler through the optical fiber, and is reflected by the right-angle reflection prism after being output from the first optical fiber coupler and incident on the atomic gas chamber, and then is incident on the zero-degree reflection mirror after passing through the quarter-wave plate and the lens in the atomic gas chamber, and returns to the first optical fiber coupler along the original path after being reflected by the zero-degree reflection mirror. The lens is used to focus the light beam so that it is coupled to the first optical fiber coupler, and the quarter-wave plate is used to change the polarization of the detection light passing through twice by 90° and then separate it from the original incident light through the PBS prism.

[0013] The atomic array probe also includes a protective cover and a partition. The protective cover is arranged outside each linearly arranged atomic gas chamber to isolate external electromagnetic field interference. The partition is arranged between each atomic gas chamber to isolate optical path interference between each atomic gas chamber.

[0014] The signal acquisition and processing component includes a filter, a photodetector array, a signal acquisition card and a signal processor. The filter is used to filter out the pump light in the detection pump light combination returned from each atomic gas chamber. The photodetector array is used to detect the detection light returned from each atomic gas chamber. After the detection signal is collected by the signal acquisition card, the microwave target intensity is calculated by the signal processor.

[0015] The Cassegrain antenna includes a coaxially arranged main reflector, a sub-reflector and a microwave collecting device, and also includes a scissor-type lifting platform, a rotating platform, a supporting platform, a telescopic rod, a rotating arm and a driving motor. The rotating platform is arranged on the scissor-type lifting platform, the driving motor is fixed on the rotating platform, one end of the rotating arm is connected to the driving motor shaft, and the other end is fixedly connected to the supporting platform; the main reflector, the sub-reflector and the microwave collecting device are arranged on the supporting platform, and the microwave collecting device is arranged on the supporting platform through the telescopic rod.

[0016] The main reflector includes a plurality of centrosymmetric antenna panels, and the antenna panels are connected to the support platform via a support rod and an electric telescopic rod.

[0017] The cross-band microwave target tracking and detection device further includes a controller, the output end of the signal acquisition and processing component is connected to the controller, and the controller is connected to the control ends of the scissor lift platform, the rotating platform, the drive motor, the telescopic rod and the electric telescopic rod, and is used to adjust the scissor lift platform, the rotating platform, the drive motor, the telescopic rod and the electric telescopic rod according to the measurement results to realize automatic tracking and aiming of the Cassegrain antenna;

[0018] The controller is also connected to the signal generator and is used to control the frequency and amplitude of the local oscillator microwave signal output by the signal generator according to the measurement result.

[0019] In addition, the present invention also provides a cross-band microwave target tracking and detection method, which is implemented according to the cross-band microwave target tracking and detection device, and includes the following steps:

[0020] Step 1: Turn on the light source component and the antenna component, measure the microwave target through the signal acquisition and processing component, and obtain preliminary information of the microwave target;

[0021] Step 2: Adjust the frequency and amplitude of the local oscillator microwave signal of the signal generator output signal to maximize the measured microwave signal intensity;

[0022] Step 3: Adjust the opening angle of the main reflector by controlling the length of the electric telescopic rod, adjust the position of the microwave collecting device by controlling the length of the telescopic rod, adjust the pitch of the Cassegrain antenna by controlling the rotation angle of the rotating table and the driving motor, and adjust the height of the Cassegrain antenna by controlling the lifting and lowering of the scissor lift table until the measured microwave signal intensity is maximum.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention proposes a cross-band microwave target tracking and detection device and method. Microwave signals are detected by an atomic array probe including multiple atomic gas chambers. Each atomic gas chamber is excited to a different Rydberg state, so that multi-band microwave measurement can be achieved, so that the measurement frequency band can cover 1 to 20 GHz; and the evanescent field formed by the surface waveguide is used to enhance the microwave electric field intensity, thereby further improving the measurement accuracy. In addition, the present invention uses a Cassegrain antenna for measurement, and the antenna structure is relatively compact and relatively convenient to manufacture; a main reflector composed of multiple antenna panels has a variable curvature; by designing the antenna structure, the antenna inclination angle is adjustable, and automatic tracking and aiming can be achieved. In addition, the present invention controls the microwave collection device by a telescoping rod, so as to solve the problem of low collection efficiency caused by changes in the convergence point of cross-band microwave signals, and greatly improves the efficiency of the antenna in receiving microwave signals; therefore, the present invention has the advantages of high sensitivity, large frequency band range, high accuracy, and all-round tracking and measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the structure of a cross-band microwave target tracking and detection device provided in Embodiment 1 of the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of the atomic array probe detection in the first embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the structure of a light source assembly in Embodiment 1 of the present invention;

[0028] Figure 4 is a schematic structural diagram of an antenna assembly in Embodiment 1 of the present invention;

[0029] Figure 5 A flowchart of a cross-band microwave target tracking and detection device provided in Embodiment 1 of the present invention;

[0030] Figure 6 A flowchart of a cross-band microwave target tracking and detection method provided by Embodiment 2 of the present invention;

[0031] In the figure, 1-electronic power divider; 2-signal generator; 3-Cassegrain antenna; 4-controller; 5-light source assembly; 6-PBS prism; 7-photodetector array; 8-signal acquisition card; 9-signal processor; 10-display screen; 11-detection laser; 12-stabilizer; 13-first beam splitter; 14-pump laser; 15-second beam splitter; 16-AOM; 17-dichroic mirror; 18-reflector; 19-atomic array probe; 20-collimator; 21-second fiber coupler; 22-filter; 3-1-sub-reflector; 3-2-support column; 3-3-main reflector; 3-4-antenna panel; 3-5-electric telescopic rod; 3-6-support rod; 3-7-microwave collecting device; 3-8-telescopic rod; 3-9-fixed table; 3-10-support table; 3-11-rotating arm; 3-12-driving motor; 3-13-rotating table; 3-14-scissor lift table; 19-1-protective cover; 19-2-first optical fiber coupler; 19-3-surface waveguide; 19-4-microwave transmission interface; 19-5-atomic gas chamber; 19-6-right-angle reflecting prism; 19-7-partition; 19-8-quarter wave plate; 19-9-lens, 19-10-zero-degree reflecting mirror. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0033] like Figure 1 As shown, the present embodiment provides a cross-band microwave target tracking and detection device, including: a light source component 5, an atomic array probe 19, an antenna component and a signal acquisition and processing component.

[0034] The light source assembly 5 is used to provide a plurality of detection pump light combinations to the atomic array probe; each of the detection pump light combinations includes a detection light beam and a pump light beam, and the detection light wavelengths in each detection pump light combination are the same, and the pump light wavelengths are different, which are used to excite different Rydberg states of atoms.

[0035] like Figure 1 As shown, the antenna assembly includes a Cassegrain antenna 3, a signal generator 2 and an electronic power divider 1, the Cassegrain antenna 3 is used to receive the microwave signal sent by the microwave target, the signal generator 2 is used to generate a local oscillator microwave signal, and the electronic power divider 1 is used to combine the microwave signal sent by the microwave target and the local oscillator microwave signal and send them to the atomic array probe.

[0036] like Figure 2 As shown, in this embodiment, the atomic array probe 19 includes a surface waveguide 19-3 and a plurality of linearly arranged atomic gas chambers 19-5, and the atomic gas chambers 19-5 are arranged on the surface waveguide 19-3; the atomic gas chamber 19-5 located at the head end is provided with a microwave transmission interface 19-4, and the microwave transmission interface 19-4 is used to transmit the microwave signal output by the electronic power divider to each atomic gas chamber 19-5; each detection pump light combination output by the light source component corresponds to an atomic gas chamber 19-5 respectively; each atomic gas chamber 19-5 is provided with a light guide device, and the light guide device is used to reversely incident the corresponding detection pump light combination to the atomic gas chamber 19-5 along the microwave emission direction, and is also used to make the detection light in the detection pump light combination return along the original path and be received by the signal acquisition and processing component. Among them, the surface waveguide 19-3 has a microwave amplification effect, which can realize the enhancement of local microwave signals, improve the atomic sensing microwave signal intensity of the atomic gas chamber 19-5, and further improve the measurement accuracy. In this embodiment, the signal to be measured is finally written into the detection light through the Cassegrain antenna, the coaxial line, the surface waveguide, and the Rydberg atomic gas cell. The microwave transmission interface 19-4 is an SMA interface.

[0037] In this embodiment, the substrate layer of the surface waveguide 19-3 is made of aluminum oxide with a high dielectric constant, and two coplanar and parallel metal plates are arranged on its surface. An evanescent field with a polarization direction parallel to the surface of the surface waveguide 19-3 is formed between the metal plates, and the evanescent field has a strong local enhanced electric field. The signal to be measured received by the antenna is propagated between the metal plates, and the signal to be measured will form a standing wave field on the surface of the surface waveguide 19-3, with multiple maximum and minimum points. When the atomic gas chamber 19-5 as an atomic sensor probe is arranged on the surface of the surface waveguide 19-3, the arrangement position of the atomic gas chamber 19-5 can be set at the maximum field distribution position according to the standing wave field distribution formed on the surface waveguide 19-3 at the measured frequency point.

[0038] In this embodiment, the signal acquisition and processing component is used to receive the detection light returned by each atomic gas chamber 9-4, and realize microwave measurement according to the intensity of the detection light.

[0039] Furthermore, if Figure 3As shown, in this embodiment, the light source assembly includes a detection laser 11, a pump laser 14, a first beam splitter 13, a second beam splitter 15, multiple AOMs 16, multiple dichroic mirrors 17, and multiple PBS prisms 6. The detection light output by the detection laser 11 is divided into multiple beams by the first beam splitter, and each beam of detection light is incident on a dichroic mirror 17 after passing through a reflector 18. The pump light output by the pump laser 1 is divided into multiple beams by the second beam splitter 5, and each beam of pump light is incident on a dichroic mirror 17 after being frequency-shifted by an AOM 6. The dichroic mirror 17 is used to combine the corresponding detection light and pump light to form a detection pump light combination and then send it to the PBS prism 6. The PBS prism 6 is used to send the detection pump light combination to the corresponding atomic gas chamber 19-5 via optical fiber.

[0040] Furthermore, if Figure 3 As shown, the light source assembly also includes a collimator 20 and a second fiber coupler 21, wherein the detection light and the coupling light are sequentially transmitted through the PBS prism 6, the collimator 20, and the second fiber coupler 21, and then sent to the atomic gas chamber 19-5 through the optical fiber.

[0041] In addition, the light source assembly further includes a frequency stabilizer 12 for stabilizing the laser light of the detection laser 11 .

[0042] Specifically, in this embodiment, the atomic gas chamber 19-5 is a cesium atomic glass vapor cell, the detection laser wavelength is 852nm, and the pump laser wavelength is 510nm.

[0043] Specifically, in this embodiment, the frequencies of 1.2 GHz, 1.5 GHz, 2.5 GHz and 12 GHz are used as adjacent Rydberg energy level transition channels, and there are four atomic gas chambers 19-5. The pump light output by the pump laser is divided into four beams by the second beam splitter. The wavelengths of the pump light after passing through each AOM are 508.660 nm, 508.718 nm, 508.903 nm and 508.678 nm, respectively. The corresponding Rydberg state is locked by resonant excitation, and the corresponding 89D 3 / 2 –90P 1 / 2 、83D 3 / 2 –84P 1 / 2 , 70D 3 / 2 –71P 1 / 2 and 87D 3 / 2 –87P 3 / 2 The transition channel of the EIT-AT split spectrum and the atomic superheterodyne signal can be recorded by the signal acquisition and processing component to achieve microwave measurement of the corresponding frequency point. The frequency of the detection light output by the detection laser is 852nm. The different Rydberg states in each atomic gas chamber 19-5 couple microwaves of different bands, which can achieve cross-band detection of target microwaves in the frequency range of 1-20GHz.

[0044] Specifically, in this embodiment, the detection laser 11 uses a semiconductor laser produced by Toptica, model Toptica SHGPro, and the pump laser 14 uses an external cavity semiconductor laser produced by Toptica, model Toptica SHG Pro; the signal generator 2 uses a brand of Keysight, model N5183B; the photodetector array 7 uses a detector produced by Thorlabs, model DET-10A; the signal acquisition card 8 uses a model PCI-6733.

[0045] Furthermore, if Figure 2 As shown, in this embodiment, the light-guiding device includes: a first optical fiber coupler 19-2, a right-angle reflection prism 19-6, a quarter-wave plate 19-8, a lens 19-9 and a zero-degree reflection mirror 19-10. The right-angle reflection prism 19-6 is arranged at the end of the atomic gas chamber 19-5. The detection pump light combination is transmitted to the first optical fiber coupler 19-2 through the optical fiber, and after being output from the first optical fiber coupler 19-2, it is reflected by the right-angle reflection prism 19-6 and incident on the atomic gas chamber 19-5. Then, it passes through the quarter wave plate 19-8 and the lens 19-9 in the atomic gas chamber 19-5 and is incident on the zero-degree reflector 19-10. After being reflected by the zero-degree reflector 19-10, it returns to the first optical fiber coupler 19-2 along the original path. The lens 19-9 is used to focus the light beam so that it is coupled to the first optical fiber coupler 19-2. The quarter wave plate 19-8 is used to change the polarization of the twice-passed detection light by 90° and then separate it from the original incident light through the PBS prism 6. In this embodiment, since the returned 852nm detection laser passes through the quarter wave plate 19-8 twice, the polarization direction of the 852nm laser returning to the PBS prism 6 is perpendicular to the incident light, so that the incident light and the returned reflected light are separated at the PBS prism 6. Then, the return light corresponding to each atomic gas chamber is filtered out by the filter 22 to remove the coupled light, and the detection light is subsequently received and processed by the signal acquisition and processing component.

[0046] Specifically, in this embodiment, the zero-degree reflector 19 - 10 may be a high-reflection film disposed on the inner surface of the atomic gas chamber 19 - 5 .

[0047] Furthermore, if Figure 2 As shown, in this embodiment, the atomic array probe also includes a protective cover 19-1 and a partition 19-7. The protective cover is arranged on the outside of each linearly arranged atomic gas chamber 19-5 to isolate external electromagnetic field interference. The partition 19-7 is arranged between each atomic gas chamber 19-5 to isolate the optical path interference between each atomic gas chamber 19-5.

[0048] Specifically, in this embodiment, Figure 1 As shown, the signal acquisition and processing component includes a filter 22, a photodetector array 7, a signal acquisition card 8 and a signal processor 9. After the reflected light returned to the PBS prism 6 is filtered out by the filter 22 to remove the pump light, the detection light is received by the photodetector array 7, and the optical signal is further converted into an electrical signal and collected and processed by the signal acquisition card 8 and the signal processor 9. The filter 22 is used to filter out the pump light in the detection pump light combination returned from each atomic gas chamber 19-5, and the photodetector array 7 is used to detect the detection light returned from each atomic gas chamber 19-5. After the detection signal is collected by the signal acquisition card 8, the microwave target intensity is calculated by the signal processor 9.

[0049] In addition, in this embodiment, the signal acquisition and processing component further includes a display screen 10, which is connected to the signal processor 9 and is used to display the measurement results.

[0050] Furthermore, in this embodiment, since the position of the cross-band microwave signal gathered by the Cassegrain antenna changes with the wavelength of the microwave, the Cassegrain antenna has a tracking function. Specifically, Figure 4 As shown, the Cassegrain antenna 3 includes a coaxially arranged main reflector 3-3, a sub-reflector 3-1 and a microwave collecting device 3-7. In addition, the Cassegrain antenna 3 also includes a scissor-type lifting platform 3-14, a rotating platform 3-13, a supporting platform 3-10, a telescopic rod 3-8, a rotating arm 3-11 and a driving motor 3-12. The rotating platform 3-13 is arranged on the scissor-type lifting platform 3-14, the driving motor 3-12 is fixed on the rotating platform 3-13, one end of the rotating arm 3-11 is connected to the rotating shaft of the driving motor 3-12, and the other end is fixedly connected to the supporting platform 3-10; the main reflector 3-3, the sub-reflector 3-1 and the microwave collecting device 3-7 are arranged on the supporting platform 3-10, and the microwave collecting device 3-7 is arranged on the supporting platform 3-10 through the telescopic rod 3-8. The height of the Cassegrain antenna can be adjusted by the scissor lift 3-14, and the inclination angle of the Cassegrain antenna in the direction of the motor shaft can be adjusted by driving the rotating arm by the drive motor 3-12. Combined with the rotation of the rotating platform 3-13, the two-dimensional pitch angle of the entire Cassegrain antenna can be adjusted.

[0051] Furthermore, in this embodiment, the main reflector 3-3 includes a plurality of centrally symmetrical antenna panels 3-4, each of which is fan-shaped and centrally symmetrically arranged to form the main reflector 3-3; the antenna panels 3-4 are connected to the support platform 3-10 via a support rod 3-6 and an electric telescopic rod 3-5; wherein, by controlling the length extension and contraction of the electric telescopic rod 3-5, a slight change in the angle of the main reflector 3-3 can be achieved, thereby achieving more accurate reception of microwave signals.

[0052] Furthermore, if Figure 1 As shown, a cross-band microwave target tracking and detection device in this embodiment also includes a controller 4, the output end of the signal acquisition and processing component is connected to the controller 4, and the controller 4 is connected to the control end of the scissor lift 3-14, the rotating table 3-13, the drive motor 3-12, the telescopic rod 3-8 and the electric telescopic rod 3-5, and is used to adjust the scissor lift 3-14, the rotating table 3-13, the drive motor 3-12, the telescopic rod 3-8 and the electric telescopic rod 3-5 according to the measurement results to achieve automatic tracking of the Cassegrain antenna. In addition, the controller is also connected to the signal generator 2, and is used to control the frequency and amplitude of the local oscillator microwave signal output by the signal generator 2 according to the measurement results.

[0053] Furthermore, in this embodiment, the controller 4 is also used to control the laser Rabi frequency output by the light source assembly. By controlling the laser Rabi frequency, the local oscillator microwave electric field frequency, the amplitude and other parameters, the measurement signal is continuously optimized, and the atoms are adjusted to a Rydberg state that is more suitable for measurement, more accurate measurements can be achieved in all directions across frequency bands.

[0054] The output end of the signal acquisition and processing component is connected to the control end of the scissor lift platform 3-14, the rotating platform 3-13, the drive motor 3-12, the telescopic rod 3-8 and the electric telescopic rod 3-5, and is used to adjust the scissor lift platform 3-14, the rotating platform 3-13, the drive motor 3-12, the telescopic rod 3-8 and the electric telescopic rod 3-5 according to the measurement results to realize automatic tracking and aiming of the Cassegrain antenna.

[0055] Specifically, the opening angle of the main reflector 3-3 can be adjusted by controlling the length of the electric telescopic rod to better receive the microwave target. In addition, the position of the microwave collecting device 3-7 can be adjusted by controlling the length of the telescopic rod 3-8 to adapt to the changes in the convergence point of the Cassegrain antenna caused by the microwave wavelength. The pitch of the Cassegrain antenna can be adjusted by controlling the rotation angle of the rotating table 3-13 and the driving motor 3-12. The height of the Cassegrain antenna can be adjusted by controlling the lifting and lowering of the scissor-type lifting platform 3-14, ultimately achieving the tracking and reception of microwave targets.

[0056] In this embodiment, compared with the traditional classical parabolic antenna, a Cassegrain antenna combining a main reflector 3-3, an antenna panel 3-4, a sub-reflector 3-1, and a microwave collecting device 3-7 is used, which makes the structure of the antenna more compact and convenient to manufacture. In the Cassegrain antenna, the main reflector 3-3 is a rotating parabola, and the sub-reflector 3-1 is a rotating hyperboloid. In terms of structure, one focus of the hyperboloid coincides with the focus of the parabola, and the focal axis of the hyperboloid coincides with the focal axis of the parabola. When the signal emitted by the microwave source radiates to the parabola of the main reflector, it converges to the virtual focus of the sub-reflector through preliminary reflection, and converges to the focus of the parabola after secondary reflection by the hyperboloid of the sub-reflector 3-1, which is equivalent to the ray directly emitted from the virtual focus of the hyperboloid. Therefore, as long as the focus of the hyperboloid coincides with that of the parabola, the rays reflected from the main reflecting surface to the secondary reflecting surface can be converged to the focus by the hyperboloid, and then collected by the microwave collecting device 3-7 and coupled to the atomic gas chamber microwave transmission interface 19-4 by the electronic power divider.

[0057] The atomic array probe in the present invention includes multiple atomic gas chambers and multiple groups of measurement optical paths, which constitute a microwave array probe. By using multiple atomic gas chambers for collaborative measurement. The measurement principle is the far-detuned AC Stark effect. When the frequency of the electromagnetic field to be measured changes in a very large range, the frequency shift caused by the AC Stark effect shows obvious resonance peaks and far-detuned corresponding characteristics. Generally speaking, resonance has the largest energy level frequency shift, so it has a more sensitive measurement sensitivity. Far-detuning gradually weakens due to the interaction intensity, so the frequency shift caused by the electromagnetic field appears to be significantly reduced relative to resonance. In the measurement range of 1-20GHz, the far-detuned response is only about 10dB lower than the position of resonance, which is much better than the classical measurement system. Moreover, the measuring device of the present invention optimizes the power and frequency of the local oscillator field according to the measurement results, which can improve the corresponding weakening of the signal caused by far-detuning relative to resonance to a certain extent and improve the sensitivity of the measurement.

[0058] The microwave electric field interacts with the atoms through dipoles, causing the energy level of the Rydberg atoms to shift in frequency, and the amount of the frequency shift is proportional to the intensity of the microwave electric field. The frequency shift of the energy level of the Rydberg atoms can be read out all-optically through electromagnetically induced transparent (EIT) spectroscopy, and the microwave information will eventually be reflected in the absorption change of the detection laser. The change in the absorption of the final detection light is converted into an electrical signal through a photodetector, which can be collected and processed using a classic acquisition card to extract the information of the electromagnetic field signal to be measured.

[0059] like Figure 5As shown, it is a working principle diagram of this embodiment. The main reflector 3-3 of the Cassegrain antenna collects microwave source signals from any direction through the mutual cooperation of each antenna panel 3-4; the sub-reflector 3-1 gathers and transmits the signal to the microwave collection device 3-7, which is transmitted to the microwave transmission SMA interface 19-4 through the coaxial line and input into the atomic gas chamber 19-5. The surface waveguide 19-3 on the surface of the atomic gas chamber 19-5 forms an evanescent field, which has a strong local enhanced electric field and can enhance the antenna collection signal to a certain extent; in addition, the antenna assembly can scan the direction of the antenna unit to achieve tracking and aiming of the target. The atomic gas chamber 19-5 is evenly placed on the surface waveguide 19-3. The 510nm pump light wavelengths in each detection pump light combination output by the light source assembly are different, which can respectively excite the atoms in the corresponding atomic gas chamber 19-5 to different Rydberg states, and then measure the electric field of the surface through multiple atoms in different Rydberg states; different Rydberg states couple microwaves of different bands to achieve cross-band detection of target microwaves in the frequency range of 1-20GHz.

[0060] During signal processing, the signal acquisition and processing component can measure and obtain preliminary phase, amplitude, and frequency information; then the controller determines whether the obtained signal is accurate, and optimizes the local oscillator microwave electric field frequency, amplitude and other parameters based on the amplitude and frequency information in the measurement information; in addition, the pump laser frequency can be optimized through feedback from the measurement information and adjusted to a Rydberg state suitable for measurement, ultimately achieving all-round high-sensitivity measurement.

[0061] Since the intensity change of the 852nm laser transmitted to the photodetector array 20 is affected by the amplitude, phase, frequency, polarization, incident angle and other factors of the microwave signal, the atomic probe unit is used as a sensor of the microwave signal, and the low-frequency electrical signal output by the photodetector array 18 can characterize the modulation information of the microwave signal. Through the electrical signal SMA interface, the low-frequency electrical signal is transmitted to the signal processing part for information collection and analysis. After the collection is completed, it is handed over to the signal processor 9 for processing and the measurement result is output on the display screen 10. At this time, analysis and judgment are carried out. If the measurement result is correct, the goal is achieved and high-sensitivity cross-band measurement is realized; if the measurement result is wrong, the result is fed back to the antenna control part through the connection between the signal processor 9 and the controller 4 for re-measurement, and this process is repeated until an accurate measurement result is obtained.

[0062] Embodiment 2

[0063] like Figure 6 As shown, the second embodiment of the present invention provides a cross-band microwave target tracking and detection method, which is implemented based on the cross-band microwave target tracking and detection device described in the first embodiment, and includes the following steps:

[0064] Step 1: Turn on the light source component and the antenna component, measure the microwave target through the signal acquisition and processing component, and obtain preliminary information of the microwave target;

[0065] Step 2: Adjust the frequency and amplitude of the local oscillator microwave signal of the signal generator output signal to maximize the measured microwave signal intensity;

[0066] Step 3: Adjust the opening angle of the main reflector 3-3 by controlling the length of the electric telescopic rod, adjust the position of the microwave collecting device 3-7 by controlling the length of the telescopic rod 3-8, adjust the pitch of the Cassegrain antenna by controlling the rotation angle of the rotating table 3-13 and the driving motor 3-12, and adjust the height of the Cassegrain antenna by controlling the lifting and lowering of the scissor lift table 3-14 until the measured microwave signal intensity is maximum.

[0067] In summary, the present invention proposes a cross-band microwave target tracking and detection device and method, which detects microwave signals through an atomic array probe including multiple atomic gas chambers, and each atomic gas chamber is excited to a different Rydberg state, so that multi-band microwave measurement can be achieved. Moreover, the evanescent field formed by the surface waveguide is used to enhance the microwave electric field strength, thereby further improving the measurement accuracy. In addition, the present invention uses a Cassegrain antenna for measurement, and the antenna structure is relatively compact and relatively convenient to manufacture. The main reflector composed of multiple antenna panels has a variable curvature. By designing the antenna structure, the antenna inclination angle is adjustable, and automatic tracking and aiming can be achieved. In addition, the present invention controls the microwave collection device through a telescopic rod, which can solve the problem of low collection efficiency caused by changes in the convergence point of cross-band microwave signals, and greatly improves the efficiency of the antenna in receiving microwave signals. Therefore, the present invention has the advantages of high sensitivity, cross-band, accuracy, and high omnidirectional tracking and measurement.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cross-band microwave target tracking and detection device, characterized in that: include: Light source assembly, atomic array probe, antenna assembly and signal acquisition and processing assembly; The light source assembly is used to provide a plurality of detection pump light combinations to the atomic array probe; the detection pump light combinations include a detection light beam and a pump light beam, the detection light wavelengths in each detection pump light combination are the same, and the pump light wavelengths are different, and are used to excite different Rydberg states of atoms; The antenna assembly comprises a Cassegrain antenna, a signal generator and an electronic power divider, wherein the Cassegrain antenna is used to receive a microwave signal sent by a microwave target, the signal generator is used to generate a local oscillator microwave signal, and the electronic power divider is used to combine the microwave signal sent by the microwave target and the local oscillator microwave signal and then send the combined signal to the atomic array probe; The atomic array probe comprises a surface waveguide (19-3) and a plurality of linearly arranged atomic gas chambers (19-5), wherein the surface waveguide (19-3) is arranged on the surface of each of the atomic gas chambers (19-5); a microwave transmission interface (19-4) is arranged on the atomic gas chamber (19-5) at the head end, and the microwave transmission interface (19-4) is used to transmit the microwave signal output by the electronic power divider into each of the atomic gas chambers (19-5); each detection pump light combination output by the light source component corresponds to an atomic gas chamber (19-5); each of the atomic gas chambers (19-5) is respectively provided with a light guide device, and the light guide device is used to reversely incident the corresponding detection pump light combination along the microwave emission direction into the atomic gas chamber (19-5), and is also used to make the detection light in the detection pump light combination return along the original path and be received by the signal acquisition and processing component; The signal acquisition and processing component is used to receive the detection light returned by each atomic gas chamber (19-5) and realize microwave measurement according to the intensity of the detection light.

2. A cross-band microwave target tracking and detection device according to claim 1, characterized in that: The light source assembly includes a detection laser, a pump laser, a first beam splitter, a second beam splitter, multiple AOMs, multiple dichroic mirrors, and multiple PBS prisms. The detection light output by the detection laser is divided into multiple beams by the first beam splitter, and each beam of detection light is incident on a dichroic mirror. The pump light output by the pump laser is divided into multiple beams by the second beam splitter, and each beam of pump light is incident on a dichroic mirror after being frequency-shifted by an AOM. The dichroic mirror is used to combine the corresponding detection light and pump light to form a detection pump light combination and then send it to the PBS prism. The PBS prism is used to send the detection pump light combination to the corresponding atomic gas chamber (19-5) via optical fiber.

3. A cross-band microwave target tracking and detection device according to claim 2, characterized in that: There are four atomic gas chambers (19-5). The pump light output by the pump laser is divided into four beams by the second beam splitter. The wavelengths of the pump light after passing through each AOM are 508.660nm, 508.718nm, 508.903nm and 508.678nm respectively. The frequency of the detection light output by the detection laser is 852nm.

4. The cross-band microwave target tracking and detection device according to claim 2, characterized in that: The light-guiding device comprises: a first optical fiber coupler (19-2), a right-angle reflection prism (19-6), a quarter-wave plate (19-8), a lens (19-9) and a zero-degree reflection mirror (19-10); the right-angle reflection prism (19-6) is arranged at the end of the atomic gas chamber (19-5); the detection pump light combination is transmitted to the first optical fiber coupler (19-2) via the optical fiber, and is output from the first optical fiber coupler (19-2) and then reflected by the right-angle reflection prism (19-6) and incident on the atomic gas chamber (19-5); then After passing through a quarter wave plate (19-8) and a lens (19-9) in the atomic gas chamber (19-5), the light is incident on a zero-degree reflector (19-10), and after being reflected by the zero-degree reflector (19-10), it returns to the first optical fiber coupler (19-2) along the original path. The lens (19-9) is used to focus the light beam so that it is coupled to the first optical fiber coupler (19-2), and the quarter wave plate (19-8) is used to change the polarization of the twice-passed detection light by 90° and then separate it from the original incident light through the PBS prism.

5. The cross-band microwave target tracking and detection device according to claim 1, characterized in that: The atomic array probe further comprises a protective cover (19-1) and a partition (19-7); the protective cover is arranged outside each linearly arranged atomic gas chamber (19-5) to isolate external electromagnetic field interference; the partition (19-7) is arranged between each atomic gas chamber (19-5) to isolate optical path interference between each atomic gas chamber (19-5).

6. The cross-band microwave target tracking and detection device according to claim 1, characterized in that: The signal acquisition and processing component comprises a filter (22), a photodetector array, a signal acquisition card and a signal processor. The filter (22) is used to filter out the pump light in the detection pump light combination returned from each atomic gas chamber (19-5). The photodetector array is used to detect the detection light returned from each atomic gas chamber (19-5). After the detection signal is collected by the signal acquisition card, the microwave target intensity is calculated by the signal processor.

7. The cross-band microwave target tracking and detection device according to claim 1, characterized in that: The Cassegrain antenna comprises a coaxially arranged main reflector (3-3), a sub-reflector (3-1) and a microwave collecting device (3-7), and also comprises a scissor-type lifting platform (3-14), a rotating platform (3-13), a supporting platform (3-10), a telescopic rod (3-8), a rotating arm (3-11) and a driving motor (3-12), wherein the rotating platform (3-13) is arranged on the scissor-type lifting platform (3-14), the driving motor (3-12) is fixed on the rotating platform (3-13), one end of the rotating arm (3-11) is connected to the rotating shaft of the driving motor (3-12), and the other end is fixedly connected to the supporting platform (3-10); the main reflector (3-3), the sub-reflector (3-1) and the microwave collecting device (3-7) are arranged on the supporting platform (3-10), and the microwave collecting device (3-7) is arranged on the supporting platform (3-10) through the telescopic rod (3-8).

8. The cross-band microwave target tracking and detection device according to claim 7, characterized in that: The main reflector (3-3) comprises a plurality of centrosymmetric antenna panels (3-4), and the antenna panels (3-4) are connected to the support platform (3-10) via a support rod (3-6) and an electric telescopic rod (3-5).

9. The cross-band microwave target tracking and detection device according to claim 8, characterized in that: The invention also comprises a controller (4), wherein the output end of the signal acquisition processing component is connected to the controller (4), and the controller (4) is connected to the control ends of the scissor lift platform (3-14), the rotating platform (3-13), the drive motor (3-12), the telescopic rod (3-8) and the electric telescopic rod (3-5), and is used for adjusting the scissor lift platform (3-14), the rotating platform (3-13), the drive motor (3-12), the telescopic rod (3-8) and the electric telescopic rod (3-5) according to the measurement results, so as to realize automatic tracking and aiming of the Cassegrain antenna; The controller (4) is also connected to the signal generator (2) and is used to control the frequency and amplitude of the local oscillator microwave signal output by the signal generator (2) according to the measurement result.

10. A cross-band microwave target tracking and detection method, implemented according to a cross-band microwave target tracking and detection device according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: Turn on the light source component and the antenna component, measure the microwave target through the signal acquisition and processing component, and obtain preliminary information of the microwave target; Step 2: Adjust the frequency and amplitude of the local oscillator microwave signal of the signal generator output signal to maximize the measured microwave signal intensity; Step 3: The opening angle of the main reflector (3-3) is adjusted by controlling the length of the electric telescopic rod, the position of the microwave collecting device (3-7) is adjusted by controlling the length of the telescopic rod (3-8), the pitch of the Cassegrain antenna is adjusted by controlling the rotation angle of the rotating table (3-13) and the driving motor (3-12), and the height of the Cassegrain antenna is adjusted by controlling the lifting and lowering of the scissor lift table (3-14) until the measured microwave signal intensity is maximum.

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