Three-dimensional radio frequency signal quasi-instantaneous sensing system and method based on microwave photon receiver

Abstract

The invention discloses a three-dimensional radio frequency signal quasi-instantaneous sensing system and method based on a microwave photon receiver, and the method comprises the steps: providing the microwave photon receiver, and determining the mapping relation between the signal frequency, the pitch angle and the azimuth angle of a reference electromagnetic target and the image point coordinates in the microwave photon receiver; generating a microwave vector of the to-be-tested electromagnetic target user; modulating the microwave signal to an optical carrier; generating a Gaussian light spot; light spot position information is extracted, and three-dimensional information of the electromagnetic target user to be measured is calculated based on the mapping relation between the signal frequency, the pitch angle and the azimuth angle of the reference electromagnetic target and the image point coordinates in the microwave photon receiver. The problem that a traditional system and method are prone to electromagnetic interference is solved, and the problems of system energy consumption and calculation time consumption are greatly reduced.

Description

Technical Field

[0001] The present invention relates to three-dimensional radio frequency signal detection, and in particular to a quasi-instantaneous perception method and system for three-dimensional radio frequency signals. Background Art

[0002] With the development of the information age, users' demand for data volume has also increased. It is crucial to solve the problem of denser user space and higher data throughput. The new fifth-generation (5G) communication system and the future sixth-generation (6G) communication system use higher carrier frequencies and wider instantaneous bandwidth to meet user needs. However, the use of higher frequencies will lead to an increase in spatial propagation loss, so array antennas are required to perform beamforming to achieve higher gain to compensate for spatial propagation loss. Increasing antenna gain will reduce spatial coverage, and multiple beams are required to cover the user space. In order to better align users for communication, accurate perception of user positions has become a necessary condition for high-speed communication. As the communication frequency increases, it also provides conditions for users' accurate perception.

[0003] Traditional sensing systems rely on photodiodes (PDs) to process light signals, which requires complex processing circuits; for example, digital beamforming (DBF) has an improved beamforming method that reduces the number of mixers required to make it comparable to the number of RF channels. However, a complete DBF system is limited in analog-to-digital converters (ADCs) and digital-to-analog converters (DACs), as well as digital signal processing (DSP). In addition, if ADCs and DACs are placed on each channel, DBF systems will become power-hungry and expensive.

[0004] Furthermore, the application needs of future high-speed communications place higher demands on processing speed, which is difficult to achieve within sub-nanoseconds with existing technologies. Summary of the invention

[0005] One of the purposes of the present invention is to remedy the deficiencies of the prior art and provide a quasi-instantaneous perception system for three-dimensional radio frequency signals.

[0006] To this end, some embodiments of the present application provide a three-dimensional RF signal quasi-instantaneous perception system based on a microwave photon receiver, wherein the microwave photon receiver includes: a RF array antenna module, including RF array antennas distributed at different physical locations, for receiving a first electromagnetic wave emitted by an electromagnetic target and generating a microwave signal with a microwave wave vector; an array low-noise amplifier module, for amplifying the microwave signal from the RF array antenna; an array optoelectronic modulation module, for modulating the amplified microwave signal onto an optical carrier to form a modulated optical sideband; a first delay optical path module, having a first linear delay optical path, configured to introduce a first linear delay in a first axial direction into the modulated optical sideband; wherein the aperture D of the RF array antenna and the length L of the first linear delay optical path are equal. y The second time delay optical path module has an equal-length time delay optical path configured to introduce an equal-length time delay in a second axis not parallel to the first axis to the modulated optical sideband, or has a second linear time delay optical path configured to introduce a second linear time delay in a second axis not parallel to the first axis to the modulated optical sideband, wherein for the second linear time delay, the aperture D of the RF array antenna is proportional to the length L of the second linear delay optical path x ; an optical array antenna module, used to transmit the modulated optical sideband with the first linear delay added, and the modulated optical sideband with the equal-length delay or the second linear delay added to the free space, wherein the aperture D of the RF array antenna module is proportional to the aperture d of the optical array antenna module; at least one optical processing module, used to filter out the carrier in the received modulated optical sideband with the first linear delay added, and the modulated optical sideband with the equal-length delay or the second linear delay to form the first incident light and the second incident light; at least one image sensor data acquisition module, including a lens and an image sensor located on the rear focal plane of the lens, the image sensor being used to realize receiving a first image point formed by the first incident light in real time, and extracting the first image point coordinates of the first image point, wherein the lens performs Fourier transform on the first incident light to form an image on the image sensor; and the image sensor is used to receive a second image point formed by the second incident light in real time, and extracting the second image point coordinates of the second image point, wherein the lens performs Fourier transform on the second incident light to form an image on the image sensor; and a solution module, including a setting mode in which a reference electromagnetic target is used as the electromagnetic target and a detection mode in which the electromagnetic target to be detected is used as the electromagnetic target; the solution module is configured to determine the frequency v of the reference electromagnetic target in the setting mode RF , Pitch angle and the mapping relationship between the azimuth angle θ and the first image point coordinates and the second image point coordinates of the reference electromagnetic target; in the detection mode, based on the mapping relationship and the first image point coordinates and the second image point coordinates of the electromagnetic target to be detected, the frequency v of the electromagnetic target to be detected is determined. RF1 , Pitch angle and azimuth angle θ1.

[0007] To this end, some other embodiments of the present application provide a three-dimensional RF signal quasi-instantaneous perception system based on a microwave photon receiver, wherein the microwave photon receiver includes: a RF array antenna module, including RF array antennas distributed at different physical locations, for receiving a first electromagnetic wave emitted by an electromagnetic target and generating a microwave signal with a microwave wave vector; an array low-noise amplifier module, for amplifying the microwave signal from the RF array antenna; an array optoelectronic modulation module, for modulating the amplified microwave signal onto an optical carrier to form a modulated optical sideband; a first delay optical path module, having a first linear delay optical path, configured to introduce a first linear delay in a first axial direction into the modulated optical sideband; wherein the RF array antenna aperture D and the first linear delay optical path length L y The optical array antenna module is used to transmit the modulated optical sideband with the first linear time delay added and the modulated optical sideband without the delay added to the free space, wherein the aperture D of the radio frequency array antenna module is proportional to the aperture d of the optical array antenna module; at least one optical processing module is used to filter out the carrier in the received modulated optical sideband with the first linear time delay added and the modulated optical sideband without the delay added to form a first incident light and a second incident light; at least one image sensor data acquisition module includes a lens and an image sensor located on the rear focal plane of the lens, wherein the image sensor is used to receive the first incident light formed by the first incident light in real time. image point, and extract the first image point coordinates of the first image point, wherein the lens performs Fourier transform on the first incident light to form an image on the image sensor; and the image sensor is used to receive in real time a second image point formed by the second incident light, and extract the second image point coordinates of the second image point, wherein the lens performs Fourier transform on the second incident light to form an image on the image sensor; and a solution module; including a setting mode in which a reference electromagnetic target is used as the electromagnetic target and a detection mode in which the electromagnetic target to be detected is used as the electromagnetic target; the solution module is configured to determine the frequency v of the reference electromagnetic target in the setting mode. RF , Pitch angle and the mapping relationship between the azimuth angle θ and the first image point coordinates and the second image point coordinates of the reference electromagnetic target; in the detection mode, based on the mapping relationship and the first image point coordinates and the second image point coordinates of the electromagnetic target to be detected, the frequency v of the electromagnetic target to be detected is determined.RF1 , Pitch angle and azimuth angle θ1.

[0008] In some embodiments, the system further comprises a display module for displaying the frequency v of the electromagnetic target to be detected. RF1 , Pitch angle and azimuth angle θ1 for display.

[0009] In some embodiments, the first time delay optical path module has a first linear time delay optical path; the second time delay optical path module has a second linear time delay optical path; the first axis is along the vertical direction; the second axis is along the horizontal direction; the mapping relationship between the first reference electromagnetic target image point coordinates (u1, v1) and the second reference electromagnetic target image point coordinates (u2, v2) of the reference electromagnetic target is:

[0010]

[0011]

[0012]

[0013]

[0014] Among them, v sb represents the optical carrier frequency, v RFO represents the center frequency of the measured frequency bandwidth, f represents the focal length of the imaging lens, S is the aperture reduction factor, k1 is the optical path linearity factor along the Y axis,

[0015] ΔL max1 represents the maximum optical path length difference along the Y-axis, k2 is the linear factor along the X-axis, ΔL max2 It represents the maximum optical path length difference along the X-axis, and D is the aperture size of the RF array antenna; according to the formula:

[0016]

[0017]

[0018]

[0019] According to the first image point coordinates (u 1a 、v 1a ) and the second image point coordinates

[0020] (u 2a 、v 2a ) calculates the frequency, azimuth and elevation angle of the electromagnetic target to be detected.

[0021] In some embodiments, the at least one optical processing module includes a first optical processing module for receiving a modulated optical sideband to which a first linear delay is added, and a second optical processing module for filtering out a carrier in the modulated optical sideband to which the equal-length delay or the second linear delay is added to form a first incident light and a second incident light.

[0022] In some embodiments, the at least one image sensor data acquisition module includes a first image sensor data acquisition module and a second image sensor data acquisition module; wherein the first image sensor data acquisition module includes a first lens and a first image sensor located on a rear focal plane of the first lens, the first image sensor is used to receive a first image point formed by the first incident light in real time, and extract the first image point coordinates of the first image point, wherein the first lens performs Fourier transform on the first incident light to form an image on the first image sensor; and the second image sensor data acquisition module includes a second lens and a second image sensor located on a rear focal plane of the second lens, the second image sensor is used to receive a second image point formed by the second incident light in real time, and extract the second image point coordinates of the second image point, wherein the second lens performs Fourier transform on the second incident light to form an image on the second image sensor.

[0023] In some embodiments, the image sensor is a CCD image sensor or a CMOS image sensor.

[0024] In some embodiments, the solution module is further configured to: calculate the maximum points of the Fourier change of the first light field function of the first outgoing light of the electromagnetic target to be measured and the Fourier change of the second light field function of the second outgoing light of the electromagnetic target to be measured, and use the maximum point of the first light field function as the first image point coordinates of the electromagnetic target to be measured, and use the maximum point of the second light field function as the second image point coordinates of the electromagnetic target to be measured.

[0025] Some other embodiments of the present application provide a method for quasi-instantaneously sensing a three-dimensional radio frequency signal based on any one of the above-mentioned three-dimensional radio frequency signal quasi-instantaneously sensing systems based on a microwave photon receiver, which comprises the steps of: providing a microwave photon receiver, adjusting a solution module of the microwave photon receiver to a setting mode, determining a frequency v of the reference electromagnetic target RF , Pitch angle and the mapping relationship between the azimuth angle θ and the first image point coordinates and the second image point coordinates of the reference electromagnetic target; adjusting the solution module to determine the frequency v of the electromagnetic target to be detected based on the mapping relationship and the first image point coordinates and the second image point coordinates of the electromagnetic target to be detected in the detection mode. RF1, Pitch angle and azimuth angle θ1.

[0026] The beneficial effects of the system and / or method of the application include: the present invention processes microwave signals optically and modulates the microwave signals onto an optical carrier for processing, which has strong anti-electromagnetic interference capability and ultra-large bandwidth; the present invention uses a camera to receive signals, eliminating a large number of ADC / DAC modules and RF mixers, filters and other devices, reducing the power consumption and cost of the system. The present invention uses a camera to replace a PD, which is more suitable for receiving large-bandwidth signals. In theory, this method is not limited by bandwidth, and data processing can be performed in parallel. The processing speed is not affected by bandwidth and the number of users. It supports multi-band and multi-beam scenarios and is suitable for multi-user and multi-beam perception within a wide frequency range. The distributed aperture sensing of electromagnetic target positions and the passive delay processing method sensing of electromagnetic target frequencies greatly save computing time and energy consumption, achieve quasi-instantaneous detection and are applicable to more carriers. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A flowchart of obtaining the mapping relationship between the signal frequency, elevation angle and azimuth angle of the reference electromagnetic target and the image point coordinates in the three-dimensional radio frequency signal quasi-instantaneous sensing method based on a microwave photon receiver in an embodiment of the present invention;

[0028] Figure 2 To establish a three-dimensional information coordinate system and an electromagnetic target scene graph in a method according to an embodiment of the present application;

[0029] Figure 3 A schematic diagram of establishing a rectangular coordinate system for a radio frequency array antenna plane in a method according to an embodiment of the present application;

[0030] Figure 4 A schematic diagram of establishing a rectangular coordinate system for the optical array antenna plane in the method according to an embodiment of the present application;

[0031] Figure 5 A schematic diagram of the length of the first part of the time delay optical path in the method according to an embodiment of the present application;

[0032] Figure 6 is a schematic diagram of the length of the second part of the time delay optical path in the method according to an embodiment of the present application;

[0033] Figure 7 A schematic diagram of establishing an image point coordinate system for an image plane of an image sensor in a method according to an embodiment of the present application;

[0034] Figure 8 is a schematic diagram of a wave vector space in a method according to an embodiment of the present application;

[0035] Fig. 9The figure is a schematic diagram of a system according to an embodiment of the present application.

[0036] Fig.10 It is a schematic diagram of the principle of a system according to another embodiment of the present application. Specific implementation methods

[0038] The scheme of the present invention is described in detail according to the accompanying drawings, but the protection scope of the present invention is not limited to the following description.

[0039] As attached Figure 1 As shown, the present application proposes a method for quasi-instantaneously sensing three-dimensional radio frequency signals based on a microwave photon receiver.

[0040] The method is based on a microwave photon receiver, the microwave photon receiver Fig. 9 The system shown includes an array subsystem 10 configured to receive radio frequency signals and convert them into modulated array optical signals, a delay processing subsystem 20 configured to perform optical processing on the modulated array optical signals and add true delays in branching, and a back-end data acquisition and computing subsystem 30 that acquires and processes the array optical signals after adding true delays to obtain three-dimensional radio frequency information.

[0041] The array subsystem 10 includes a radio frequency array antenna module 11, including radio frequency array antennas distributed at different physical locations, for receiving electromagnetic waves emitted by a reference electromagnetic target and generating microwave signals with microwave wave vectors; an array low noise amplifier module 12, including multiple low noise amplifiers for amplifying the microwave signals from the radio frequency array antenna; and an array photoelectric modulation module 13, including multiple photoelectric modulation units for modulating the amplified microwave signals onto an optical carrier to form modulated optical sidebands. The number of radio frequency array antennas in the radio frequency array antenna module 11, the number of low noise amplifiers in the array low noise amplifier module 12, and the number of photoelectric modulation units in the array photoelectric modulation module 13 match each other, for example, they are all n.

[0042] Among them, in some embodiments, the delay processing subsystem 20 has a first optical path and a second optical path, and a first delay optical path module 21 is provided on the first optical path, having a first delay optical path length that can be linearly increased, and is configured to introduce a first linear delay in the first axis to the modulated optical sideband; a second delay optical path module 22 is provided on the second optical path, having a second delay optical path length that can be linearly increased, and is configured to introduce a second linear delay in the second axis that is not parallel to the first axis to the modulated optical edge. In some embodiments, the first delay optical path module 21 is, for example, a Y-axis delay optical path module, which is used to introduce a linear delay in the vertical direction; the second delay optical path module 22 is, for example, an X-axis delay optical path module, which is used to introduce a linear delay in the horizontal direction. It should be understood that the first axis of the first delay optical path module 21 and the second axis of the second delay optical path module 22 do not need to be parallel, and there is no need to maintain the vertical relationship between the above-mentioned X-axis and Y-axis, and only the solution formula is different. The first delay optical path module 21 and the second delay optical path module 22 are, for example, optical fiber delay lines, optical fiber circulators, etc. Among them, the number of delay paths in the first delay optical path module 21 or the second delay optical path module 22 can match the number of RF array antennas in the above-mentioned RF array antenna module 11, the number of low noise amplifiers in the array low noise amplifier module 12, and the number of optoelectronic modulation units in the array optoelectronic modulation module 13, for example, all are n paths. For the first delay optical path module 21 or the second delay optical path module 21, which is an embodiment that provides linear delay, the delays of the n paths are linearly distributed, and for the embodiment that provides equal-length delays, the delays of the n paths are the same. For the embodiment that does not provide delay, the optical fibers in the second pipeline are of equal length.

[0043] Among them, the delay processing subsystem 20 also includes an optical antenna array 23 for emitting the modulated optical sideband that introduces the first linear delay or the second linear delay as spatial light; the first optical processing module 24 is used to filter out the optical carrier with a first filter from the modulated optical sideband that introduces the first linear delay to form a first incident light, which is then focused to the first image sensor by the first lens of the first image sensor data acquisition module 31 of the back-end data acquisition and calculation subsystem 30; the second optical processing module 25 is used to filter out the optical carrier with a second filter from the modulated optical sideband that introduces the second linear delay to form a second incident light, which is then focused to the second image sensor by the second lens of the second image sensor data acquisition module 32 of the back-end data acquisition and calculation subsystem 30.

[0044] It should be understood that in some embodiments, the second delay optical path module 22 of the second optical path of the delay processing subsystem 20 can be configured to introduce equal-length delays, such as optical fiber delay lines of equal length rather than optical fiber delay lines of linear length, thereby introducing equal-length delays for the modulated light on the second optical path.

[0045] It should be understood that in some embodiments, the second optical path of the delay processing subsystem 20 may not include the second delay optical path module 22. In this way, on the second optical path, the modulated optical sideband can be sent to the optical antenna array 23 only through ordinary optical fiber.

[0046] Among them, the back-end data acquisition and calculation subsystem 30 includes a first image sensor data acquisition module 31, which is used to receive in real time a first image point formed by the first incident light and extract the first image point coordinates of the first image point; and a second image sensor data acquisition module 32, which is used to receive in real time a second image point formed by the second incident light and extract the second image point coordinates of the second image point.

[0047] The back-end data acquisition and calculation subsystem 30 also includes a solver module 33, which is used to receive the reference electromagnetic target image point position coordinates for the reference electromagnetic target from the first image sensor data acquisition module 31 and the second image sensor data acquisition module 32, such as the first reference electromagnetic target image point coordinates and the second reference electromagnetic target image point coordinates, and determine the mapping relationship between the pitch angle, azimuth angle and frequency information of the reference electromagnetic target according to the first reference electromagnetic target image point coordinates and the second reference electromagnetic target image point coordinates.

[0048] The solver module 33 also receives the image point position coordinates of the electromagnetic target to be measured from the first image sensor data acquisition module 31 and the second image sensor data acquisition module 32, such as the image point coordinates of the first electromagnetic target to be measured and the image point coordinates of the second electromagnetic target to be measured, and determines the three-dimensional information such as the pitch angle, azimuth angle and frequency information of the electromagnetic target to be measured according to the mapping relationship between the image point coordinates of the first electromagnetic target to be measured, the image point coordinates of the second electromagnetic target to be measured, and the image point position coordinates of the reference electromagnetic target and the pitch angle, azimuth angle and frequency information of the reference electromagnetic target. The solver module 33 is, for example, a computer running a solver based on a processor, or other intelligent device.

[0049] The back-end data acquisition and calculation subsystem 30 may further include a terminal display module 34 for displaying the three-dimensional information of the electromagnetic target to be measured in a three-dimensional information coordinate system.

[0050] Acquiring the mapping relationship between the signal frequency, elevation angle and azimuth angle of the reference electromagnetic target and the image point coordinates specifically includes the following steps of setting a microwave photon receiver:

[0051] Step S1: Provide a user-carried communication device as a reference electromagnetic target in a given electromagnetic environment perception scenario. To ensure the normal operation of the communication device, the communication device as the reference electromagnetic target will radiate electromagnetic signals in real time for functions such as communication and positioning.

[0052] Step S2, setting the radio frequency array antenna 11: establishing a three-dimensional information coordinate system with the radio frequency array antenna 11 as the origin, and generating the signal frequency of the reference electromagnetic target and the pitch angle and azimuth angle of the reference electromagnetic target. Figure 2 As shown, a three-dimensional information coordinate system is established with the RF array antenna 11 as the origin, including the frequency v of the reference electromagnetic target RF , azimuth and pitch angle θ parameters; the reference electromagnetic target i can be expressed as where v RF represents the frequency of electromagnetic waves radiated by reference electromagnetic target i, represents the azimuth angle of the arrival direction of the electromagnetic wave radiated by the reference electromagnetic target i relative to the origin, and θ represents the pitch angle of the arrival direction of the electromagnetic wave radiated by the reference electromagnetic target i relative to the origin.

[0053] Step S3, setting the aperture of the RF array antenna 11 and the aperture of the optical array antenna 104, defining the scaling factor of the two apertures, setting the focal lengths of the first lens and the second lens, the first lens and the second lens are, for example, biconvex lenses, and establishing a rectangular coordinate system for the RF array antenna 11 and the optical array antenna 104. This step may specifically include: setting the aperture of the RF array antenna 11 to D, setting the aperture of the optical array antenna 104 to d, setting the focal length of the biconvex lens to f, and defining the aperture scaling factor as: like Figure 3 As shown, a first rectangular coordinate system XO1Y with the starting RF antenna as the first origin is established on the plane of the RF array antenna 11, and any RF antenna position in the RF array antenna 11 can be used (D X ,D Y ), for example, the position of the first origin is represented by (D0, D0). Figure 4 As shown, the optical array antenna 23 is a scaled image of the RF array antenna 11 under an aperture reduction factor S. A second rectangular coordinate system xO2y is established on the plane of the optical array antenna 23 with the starting optical antenna of the optical array antenna 23 as the second origin. Any optical antenna position in the optical array antenna 23 can be used (d x ,d y ), for example, the second origin position is represented by (d0, d0).

[0054] Step S4, determining the relationship between the aperture of the RF array antenna 11 and the length of the first linear delay optical path of the first delay optical path module 21 and the length of the second linear delay optical path of the second delay optical path module 22. The length of the first linear delay optical path of the first delay optical path module 21 is sampled along the Y axis of the aperture of the RF array antenna 11, Figure 5As shown, the length of the second linear delay optical path of the second delay optical path module 22 is sampled along the aperture X-axis of the radio frequency antenna. Figure 6 As shown, the relationship between the length of the first linear delay optical path and / or the length of the second linear delay optical path and the aperture of the RF array antenna 11 is expressed as: L y = k·D yi ; L x = k·D xi Among them, L y represents the length of the first linear delay optical path, L x represents the length of the second linear delay optical path, k is defined as the linear factor of the first linear delay optical path and the second linear delay optical path, ΔL max represents the maximum optical path length difference between the first linear delay optical path and the second linear delay optical path, and D is the aperture size of the RF array antenna.

[0055] Step S5, setting the first reference electromagnetic target image point coordinates of the first image sensor data acquisition module 31 and the second reference electromagnetic target image point coordinates of the second image sensor data acquisition module 32, and determining the mapping relationship between the signal frequency, pitch angle and azimuth angle of the reference electromagnetic target and the first reference electromagnetic target image point coordinates and the second reference electromagnetic target image point coordinates. In this embodiment, this step specifically includes: Figure 7 As shown, a rectangular coordinate system is established using the image planes of the first image sensor data acquisition module 31 and the second image sensor data acquisition module 32 respectively, and the image planes are divided into a plurality of image point coordinates according to pixel sizes.

[0056] After the n-th modulated optical sideband with the first time delay added is filtered by the first optical processing module to remove the optical carrier, the Fourier transform of the first reference electromagnetic target light field is measured on the first back focal plane of the first double convex lens with a focal length of f. The Fourier transform of the first reference electromagnetic target light field is located on the first back focal plane and is collected by the first image sensor data acquisition module 31 to obtain the first reference electromagnetic target image point coordinates (u1, v1). The Fourier transform of the first reference electromagnetic target light field is in the following form: Among them, v sb is the optical carrier frequency, λ is the optical carrier wavelength, and thus the first reference electromagnetic target Gaussian spot is obtained.

[0057] After filtering and removing the optical carrier by the second optical processing module of the nth modulated optical sideband with the second delay, the Fourier transform of the second reference electromagnetic target light field is measured on the second back focal plane of the second double convex lens with a focal length of f. The Fourier transform of the second reference electromagnetic target light field is located on the second back focal plane and is collected by the second image sensor data acquisition module 32 to obtain the coordinates of the second reference electromagnetic target image point (u2, v2). The Fourier transform of the second reference electromagnetic target light field is in the form of: Among them, v sb is the optical carrier frequency, λ is the optical carrier wavelength, and thus the Gaussian spot of the second electromagnetic target to be measured is obtained.

[0058] As described above, the image plane of the first image sensor data acquisition module 31 located on the rear focal plane of the first biconvex lens, that is, the image point coordinates of the first reference electromagnetic target image point on the first image plane can be expressed as (u1, v1), and the image plane of the second image sensor data acquisition module 31 located on the rear focal plane of the second biconvex lens, that is, the image point coordinates of the second reference electromagnetic target image point on the second image plane can be expressed as (u2, v2); let the coordinates of the reference electromagnetic target in the three-dimensional information coordinate system be Then v RF , The mapping relationship between and θ and the coordinates of the first reference electromagnetic target image point (u1, v1) and the coordinates of the second reference electromagnetic target image point (u2, v2) is:

[0059]

[0060]

[0061]

[0062]

[0063] Among them, v sb represents the optical carrier frequency, v RFO represents the center frequency of the measured frequency bandwidth, f represents the lens used for imaging, such as the focal length of the biconvex lens, S is the aperture reduction factor, and k is the linear factor of the first linear delay optical path and the second linear delay optical path. It should be understood that although k is used to represent the linear factor of the first linear delay optical path and the second linear delay optical path, in practice, the two may be equal or unequal.

[0064] Identification steps:

[0065] The method for quasi-instantaneously sensing three-dimensional radio frequency signals based on a microwave photon receiver first uses the radio frequency array antenna module 11 to sense the electromagnetic signal to be measured in real time.

[0066] The electromagnetic signal to be measured from the radio frequency array antenna module 11 is amplified for subsequent processing.

[0067] The electromagnetic signal to be detected generates a microwave wave vector according to the coordinates of the electromagnetic target to be detected in the three-dimensional information coordinate system. The wave vector Contains the incoming wave direction and frequency information of the electromagnetic target to be detected; such as Figure 8 As shown, the microwave wave vector of the electromagnetic target to be measured can be expressed as: in, is the azimuth angle of the electromagnetic target to be measured relative to the RF array antenna, θ1 is the elevation angle of the electromagnetic target to be measured relative to the RF array antenna, and the frequency v RF1 .

[0068] The microwave signal having the microwave wave vector is modulated onto an optical carrier wave using a frequency v sb The phase of the modulated sideband of the optical carrier in the nth optical path is: Among them A n Represents the amplitude in the nth optical path; this step obtains the modulated light sideband of the electromagnetic target to be measured.

[0069] Generate a Gaussian light spot through the true delay. In this embodiment, this step may specifically include: in the first delay optical path module 21, the modulated optical sideband of the electromagnetic target to be measured is sampled along the Y axis of the aperture of the RF array antenna 11 along the length of the first linear delay optical path to add a first true delay, and the first true delay It can be expressed as: Wherein, c represents the speed of light in vacuum; after the n-th modulated optical sideband to which the first true delay is added is filtered by the first optical processing module to remove the optical carrier, the Fourier transform of the first light field is measured on the first back focal plane of the first double convex lens with a focal length of f, and the Fourier transform of the first light field is located on the first back focal plane and is collected by the first image sensor data acquisition module 31 to obtain the coordinates of the first electromagnetic target image point to be measured (u 1a 、v 1a ), the Fourier transform of the first light field is in the form of: Among them, v sb is the optical carrier frequency, λ is the optical carrier wavelength, thereby obtaining the Gaussian spot of the first electromagnetic target to be measured.

[0070] In the second delay optical path module 22, sampling is performed along the X-axis of the aperture of the RF array antenna over the length of the second linear delay optical path to add a second true delay. The second true delay It can be expressed as: After filtering and removing the optical carrier by the second optical processing module of the nth modulated optical sideband adding the second true delay, the Fourier transform of the second light field is measured on the second back focal plane of the second double convex lens with a focal length of f. The Fourier transform of the second light field is located on the second back focal plane and is collected by the second image sensor data acquisition module 32 to obtain the coordinates of the second electromagnetic target image point to be measured (u 2a 、v 2a ), the Fourier transform of the second light field is in the form of: Among them, v sb is the optical carrier frequency, λ is the optical carrier wavelength, and thus the Gaussian spot of the second electromagnetic target to be measured is obtained.

[0071] The three-dimensional information of the electromagnetic target to be measured is calculated according to the position of the Gaussian light spot of the first electromagnetic target to be measured in the first image plane and the position of the Gaussian light spot of the second electromagnetic target to be measured in the second image plane. In this embodiment, this step specifically includes: the total light input field is the coherent sum of all the outgoing lights, and the image point coordinates (u 1a ,v 1a ) can be expanded to:

[0072]

[0073] When all phases are zero, that is, the Gaussian spot position of the first electromagnetic target to be measured, the image point coordinates U1 (u 1a ,v 1a ) to obtain the maximum value;

[0074]

[0075]

[0076] Among them, v RFO is the center frequency of the measured frequency range;

[0077] The coordinates of the second electromagnetic target image point to be measured (u 2a ,v 2a ) can be expanded to:

[0078]

[0079] Similarly, when all phases are zero, that is, the Gaussian spot position of the second electromagnetic target to be measured, the image point coordinates of the second electromagnetic target to be measured (u 2a ,v 2a ) to obtain the maximum value;

[0080]

[0081]

[0082] Extract the coordinates of the first electromagnetic target image point to be measured on the first image sensor data acquisition module 31 (u 1a 、v 1a ) and the coordinates of the second electromagnetic target image point to be measured on the second image sensor data acquisition module (u 2a 、v 2a ); Calculate the electromagnetic target to be measured including the frequency v according to the mapping relationship between the signal frequency, pitch angle and azimuth of the reference electromagnetic target and the coordinates of the first image point and the coordinates of the second image point RF1 , azimuth The three-dimensional information of the pitch angle θ1 only requires simple algebraic calculation, so it can be realized quasi-instantaneously. The calculation formula is:

[0083]

[0084]

[0085]

[0086] In the above embodiments, the first delay optical path module and the second delay optical path module add linear delay to the incident modulated optical sideband to form n optical paths with modulated optical sidebands added with linearly distributed delays.

[0087] It should be understood that in the above embodiments, the Y-axis optical linearity factor k may be the same as or different from the X-axis optical linearity factor k. In different cases, the Y-axis optical linearity factor may be represented by k1, and the X-axis optical linearity factor may be represented by k2, thereby obtaining:

[0088]

[0089] That is, it changes linearly along the Y-axis, causing the image point to move vertically;

[0090] That is, it changes linearly along the X-axis, causing the image point to move vertically;

[0091]

[0092] Among them, v sb represents the optical carrier frequency, v RFO represents the center frequency of the measured frequency bandwidth, f represents the focal length of the imaging lens, S is the aperture reduction factor, k1 is the optical path linearity factor along the Y axis, ΔL max1represents the maximum optical path length difference along the Y-axis, k2 is the linear factor along the X-axis, ΔL max2 represents the maximum optical path length difference along the X-axis, and D is the aperture size of the RF array antenna;

[0093] It can be found that as long as k_1 and k_2 are not equal to 0 at the same time, the equation can be solved (three equations or equal to three unknowns), so an optical path with linear delay and an optical path of equal length can also be solved.

[0094] When solving the three-dimensional information of the electromagnetic target to be measured, the formula can be used:

[0095]

[0096] as well as

[0097]

[0098] According to the first electromagnetic target image point coordinates (u 1a 、v 1a ) and the coordinates of the second electromagnetic target image point to be measured (u 2a 、v 2a ) calculates three-dimensional information such as frequency, azimuth and pitch angle of the electromagnetic target to be detected.

[0099] It should be understood that although the above embodiments are described by taking the first time delay optical path module and the second time delay optical path module as examples, one of the time delay optical path modules can also be replaced by a fixed-length time delay pipeline module, so that the modulated optical sideband forms n optical paths on one path with modulated optical sidebands with linearly distributed time delays added; and forms n optical paths on another path with modulated optical sidebands with equal-length time delays added. After obtaining the coordinates of the image point through imaging by the image sensor acquisition module, the three-dimensional information of the electromagnetic target to be measured can still be solved.

[0100] It should be understood that no delay may be added to one of the paths, so that the modulated optical sideband forms n optical paths with linearly distributed delays added to the modulated optical sidebands on one path; the modulated optical sideband without delay is maintained on the other path. After obtaining the coordinates of the image points through imaging by the image sensor acquisition module, the three-dimensional information of the electromagnetic target to be measured can still be solved.

[0101] Fig.10 FIG. 2 shows a schematic diagram of the structure of a microwave photon receiver according to another embodiment of the present application. Fig. 9Different from the microwave photonic receiver in the microwave photonic receiver, the delay processing subsystem 20 in the microwave photonic receiver only includes one optical processing module, namely the first optical processing module 24. The modulated optical sidebands with delay added from the first delay optical path module 21 and the second delay optical path module 22 are filtered by the first optical processing module 24 after being emitted by the optical antenna array 23.

[0102] exist Fig.10 The microwave photon receiver shown includes only one image sensor data acquisition module, namely the first image sensor data acquisition module. The modulated optical sidebands with time delay are filtered by the first optical processing module 24 and then sent to the first image sensor data acquisition module for image point position acquisition, and then sent to the solution module for solution.

[0103] In the present application, the image sensor may be a CCD image sensor or a CMOS image sensor, preferably a CMOS image sensor.

[0104] Conventional frequency measurement schemes use PD to receive optical signals, which require local oscillator signals for down-conversion. Different local oscillator signals are required for different frequency bands to obtain intermediate frequency signals with better quality. In addition, matching high-frequency circuits are required for signal processing. When multiple users appear within the range of the base station, a large number of analog-to-digital conversion modules (ADCs) are required to sense user locations and measure frequencies, which consumes a lot of power and requires processing huge amounts of data.

[0105] In this application, image sensors such as CCD are used to receive image point information. Only the intensity information of the image point is obtained on the image sensor. It is only necessary to read out the pixels corresponding to the image point and perform simple algebraic operations to obtain the location information of the source frequency. No ADC module is required, and it has high angle and frequency resolution. If the process uses PD for reception, a large number of PDs will be required to obtain the corresponding spatial delay inference azimuth information. It is conceivable that this process requires a large number of ADC modules and complex readout circuits for calculation. This application proposes a new method. On the basis of traditional radar obtaining source position information according to the direction of the incoming wave, a delay path is added to sense the source frequency, which can realize simultaneous perception of multiple users.

[0106] This application uses a lens as a light processing module to realize the Fourier transform of modulated light sidebands. The lens is a passive device and its speed is the same as the speed of light, so it is fast and has low power consumption. Through passive light processing, the image point information can be directly received on the image sensor, and only the image point coordinates need to be extracted for simple algebraic calculations.

[0107] The description presents the basic embodiments of the present invention in detail, but should not be limited to the form described in the description, but can also be used for other purposes and environments, and can be modified based on the principles and techniques of this article according to the relevant art technology. Any changes that do not depart from the spirit and scope of the invention should be within the scope of protection of the claims attached to the present invention.

Claims

1. A three-dimensional radio frequency signal quasi-instantaneous sensing system based on a microwave photon receiver, characterized in that: The microwave photon receiver comprises: A radio frequency array antenna module, comprising radio frequency array antennas distributed at different physical locations, for receiving a first electromagnetic wave emitted by an electromagnetic target and generating a microwave signal having a microwave wave vector; An array low noise amplifier module, used for amplifying the microwave signal from the radio frequency array antenna; An array optoelectronic modulation module, used for modulating the amplified microwave signal onto an optical carrier to form a modulated optical sideband; A first time delay optical path module has a first linear time delay optical path, configured to introduce a first linear time delay in a first axis to the modulated optical sideband; wherein the aperture of the RF array antenna is proportional to the length of the first linear time delay optical path; A second time delay optical path module, having an equal-length time delay optical path configured to introduce an equal-length time delay in a second axial direction not parallel to the first axial direction to the modulated optical sideband, or having a second linear time delay optical path configured to introduce a second linear time delay in a second axial direction not parallel to the first axial direction to the modulated optical sideband, wherein for the second linear time delay, the aperture of the RF array antenna is proportional to the length of the second linear time delay optical path; An optical array antenna module, used for transmitting a modulated optical sideband to which a first linear time delay is added, and a modulated optical sideband to which the equal-length time delay or the second linear time delay is added into free space, wherein the aperture of the radio frequency array antenna module is proportional to the aperture of the optical array antenna module; At least one optical processing module, configured to filter out the carrier in the received modulated optical sideband added with the first linear delay and the modulated optical sideband added with the equal-length delay or the second linear delay to form a first incident light and a second incident light; at least one image sensor data acquisition module, comprising a lens and an image sensor located on a rear focal plane of the lens, the image sensor being used to receive a first image point formed by the first incident light in real time, and extract first image point coordinates of the first image point, wherein the lens performs Fourier transform on the first incident light to form an image on the image sensor; and the image sensor being used to receive a second image point formed by the second incident light in real time, and extract second image point coordinates of the second image point, wherein the lens performs Fourier transform on the second incident light to form an image on the image sensor; and a solution module; comprising a setting mode in which a reference electromagnetic target is used as the electromagnetic target and a detection mode in which the electromagnetic target to be detected is used as the electromagnetic target; the solution module is configured to determine the frequency (v RF )、Pitch angle( ) and the azimuth (θ) and the first image point coordinates and the second image point coordinates of the reference electromagnetic target; in the detection mode, based on the mapping relationship and the first image point coordinates and the second image point coordinates of the electromagnetic target to be detected, the frequency (v RF1 )、Pitch angle( ) and azimuth (θ1).

2. A three-dimensional radio frequency signal quasi-instantaneous sensing system based on a microwave photon receiver, characterized in that: The microwave photon receiver comprises: A radio frequency array antenna module, comprising radio frequency array antennas distributed at different physical locations, for receiving a first electromagnetic wave emitted by an electromagnetic target and generating a microwave signal having a microwave wave vector; An array low noise amplifier module, used for amplifying the microwave signal from the radio frequency array antenna; An array optoelectronic modulation module, used for modulating the amplified microwave signal onto an optical carrier to form a modulated optical sideband; A first time delay optical path module has a first linear time delay optical path, configured to introduce a first linear time delay in a first axis to the modulated optical sideband; wherein the aperture of the RF array antenna is proportional to the length of the first linear time delay optical path; An optical array antenna module, used for transmitting a modulated optical sideband with a first linear time delay added thereto and a modulated optical sideband without a time delay added thereto into free space, wherein the aperture of the radio frequency array antenna module is proportional to the aperture of the optical array antenna module; At least one optical processing module, configured to filter out the carrier in the received modulated optical sideband to which the first linear delay is added and the modulated optical sideband to which the delay is not added to form a first incident light and a second incident light; at least one image sensor data acquisition module, comprising a lens and an image sensor located on a rear focal plane of the lens, the image sensor being used to receive a first image point formed by the first incident light in real time, and extract first image point coordinates of the first image point, wherein the lens performs Fourier transform on the first incident light to form an image on the image sensor; and the image sensor being used to receive a second image point formed by the second incident light in real time, and extract second image point coordinates of the second image point, wherein the lens performs Fourier transform on the second incident light to form an image on the image sensor; and a solution module; comprising a setting mode in which a reference electromagnetic target is used as the electromagnetic target and a detection mode in which the electromagnetic target to be detected is used as the electromagnetic target; the solution module is configured to determine the frequency (v RF )、Pitch angle( ) and the azimuth (θ) and the first image point coordinates and the second image point coordinates of the reference electromagnetic target; in the detection mode, based on the mapping relationship and the first image point coordinates and the second image point coordinates of the electromagnetic target to be detected, the frequency (v RF1 )、Pitch angle( ) and azimuth (θ1).

3. The three-dimensional radio frequency signal quasi-instantaneous sensing system based on a microwave photon receiver according to claim 1 or 2, characterized in that: The device also includes a display module for displaying the frequency (v RF1 )、Pitch angle( ) and azimuth (θ1) are displayed.

4. The three-dimensional radio frequency signal quasi-instantaneous sensing system based on a microwave photon receiver according to claim 1 is characterized in that: The first time delay optical path module has a first linear time delay optical path; the second time delay optical path module has a second linear time delay optical path; the first axis is along the vertical direction; the second axis is along the horizontal direction; the mapping relationship between the first reference electromagnetic target image point coordinates (u1, v1) and the second reference electromagnetic target image point coordinates (u2, v2) of the reference electromagnetic target is: Among them, v sb represents the optical carrier frequency, v RFO represents the center frequency of the measured frequency bandwidth, f represents the focal length of the imaging lens, S is the aperture reduction factor, k1 is the optical path linearity factor along the Y axis, ΔL max1 represents the maximum optical path length difference along the Y-axis, k2 is the linear factor along the X-axis, ΔL max2 represents the maximum optical path length difference along the X-axis, and D is the aperture size of the RF array antenna; according to the formula: According to the first image point coordinates (u 1a 、v 1a ) and the second image point coordinates (u 2a 、v 2a ) calculates the frequency, azimuth and elevation angle of the electromagnetic target to be detected.

5. The three-dimensional radio frequency signal quasi-instantaneous sensing system based on a microwave photon receiver according to claim 1 or 2, characterized in that: The at least one optical processing module includes a first optical processing module for receiving a modulated optical sideband to which a first linear delay is added, and a second optical processing module for filtering out a carrier in the modulated optical sideband to which the equal-length delay or the second linear delay is added to form a first incident light and a second incident light.

6. The three-dimensional radio frequency signal quasi-instantaneous sensing system based on a microwave photon receiver according to claim 1 or 2, characterized in that: The at least one image sensor data acquisition module includes a first image sensor data acquisition module and a second image sensor data acquisition module; wherein the first image sensor data acquisition module includes a first lens and a first image sensor located on a rear focal plane of the first lens, the first image sensor is used to receive a first image point formed by the first incident light in real time, and extract a first image point coordinate of the first image point, wherein the first lens performs Fourier transform on the first incident light to form an image on the first image sensor; and the second image sensor data acquisition module includes a second lens and a second image sensor located on a rear focal plane of the second lens, the second image sensor is used to receive a second image point formed by the second incident light in real time, and extract a second image point coordinate of the second image point, wherein the second lens performs Fourier transform on the second incident light to form an image on the second image sensor.

7. The three-dimensional radio frequency signal quasi-instantaneous sensing system based on a microwave photon receiver according to claim 1 or 2, characterized in that: The image sensor is a CCD image sensor or a CMOS image sensor.

8. The three-dimensional radio frequency signal quasi-instantaneous sensing system based on a microwave photon receiver according to claim 1, characterized in that: The solution module is further configured to: calculate the maximum points of the Fourier change of the first light field function of the first outgoing light of the electromagnetic target to be measured and the Fourier change of the second light field function of the second outgoing light of the electromagnetic target to be measured, and use the maximum point of the first light field function as the first image point coordinates of the electromagnetic target to be measured, and use the maximum point of the second light field function as the second image point coordinates of the electromagnetic target to be measured.

9. A quasi-instantaneous three-dimensional radio frequency signal sensing method according to any one of the above claims, wherein: The method comprises the steps of: providing a microwave photon receiver, adjusting a solution module of the microwave photon receiver to a setting mode, determining a frequency (v RF )、Pitch angle( ) and the azimuth angle (θ) and the mapping relationship between the first image point coordinates and the second image point coordinates of the reference electromagnetic target; The solution module is adjusted to determine the frequency (v) of the electromagnetic target to be detected based on the mapping relationship and the first image point coordinates and the second image point coordinates of the electromagnetic target to be detected in the detection mode. RF1 )、Pitch angle( ) and azimuth (θ1).

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