Device and method for simultaneously measuring two-dimensional angle of arrival and Doppler frequency shift of microwave photons

Abstract

The invention discloses a device and method for simultaneously measuring the two-dimensional angle of arrival and Doppler frequency shift of microwave photons, and belongs to the technical field of optical communication and microwaves, and the device is characterized in that an output port of a laser is connected with an optical input port of a PDM-DPMZM, and an optical output port of the PDM-DPMZM is connected with a common input end of an optical beam splitter; a first output port of the optical beam splitter is connected with a common input port of a first polarization beam splitter PBS1, and two output ports of the PBS1 are respectively connected with two optical input ports of a first balance photoelectric detector BPD1; an output port II of the light beam splitter is connected with a common input port of a polarization beam splitter II PBS2; and two output ports of the PBS2 are respectively connected with two light input ports of a balance photoelectric detector I BPD2. The device is simple in structure, and can solve the problem of low positioning precision in an existing simultaneous arrival angle and DFS measurement scheme.

Description

Technical Field

[0001] The present invention relates to the fields of optical communication and microwave technology, and more specifically, to a device and method for simultaneously measuring two-dimensional angle of arrival and Doppler frequency shift of microwave photons. Background Art

[0002] In order to achieve precise positioning and velocity monitoring of targets, systems such as military reconnaissance, target tracking, intelligent transportation, and unmanned driving need to simultaneously estimate the angle of arrival (AOA) and Doppler frequency shift (DFS) of microwave signals. With the continuous improvement of measurement accuracy requirements, traditional electronic systems are facing the dual pressures of high operating frequencies and large transmission bandwidths. Due to the inherent rate bottleneck problem of electronic devices, the measurement ranges of AOA and DFS in the electrical domain are limited, and traditional electronic measurement systems are struggling in an increasingly complex electromagnetic environment.

[0003] In recent years, microwave photon-assisted microwave measurement technology has developed rapidly, showing unique advantages in terms of operating frequency, transmission bandwidth, loss, and electromagnetic interference, and thus has received extensive attention in the field of signal measurement. Currently, there have emerged various methods for simultaneously measuring AOA and DFS using microwave photons. The principle is generally to obtain DFS based on down-conversion, and then construct a mapping relationship from the phase difference or power difference of the photocurrent to AOA, and then simultaneously measure DFS and AOA. However, these AOA measurement methods can only achieve azimuth angle measurement and cannot measure the elevation angle, and the positioning accuracy is generally low, resulting in limited specific application scenarios. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a device and method for simultaneously measuring two-dimensional angle of arrival and Doppler frequency shift of microwave photons, which can solve the problem of low positioning accuracy in existing simultaneous AOA and DFS measurement schemes, has a simple structure and strong practicability, and has great prospects in military reconnaissance, target tracking, intelligent transportation, and unmanned driving applications.

[0005] The purpose of the present invention is achieved through the following solutions:

[0006] A device for simultaneously measuring two-dimensional angle of arrival and Doppler frequency shift of microwave photons includes: a laser, a polarization multiplexed dual parallel Mach-Zehnder modulator (PDM-DPMZM), an optical splitter, two polarization beam splitters (PBS), and two balanced photodetectors (BPD);

[0007] The output port of the laser is connected to the optical input port of the PDM-DPMZM. The optical output port of the PDM-DPMZM is connected to the common input end of the optical splitter. One output port of the optical splitter is connected to the common input port of the polarization beam splitter PBS1. The two output ports of PBS1 are respectively connected to the two optical input ports of the balanced photodetector BPD1. The other output port of the optical splitter is connected to the common input port of the polarization beam splitter PBS2. The two output ports of PBS2 are respectively connected to the two optical input ports of the balanced photodetector BPD2.

[0008] Furthermore, it also includes two polarization controllers PC. One output port of the optical splitter is connected to the input port of the polarization controller PC1. The output port of PC1 is connected to the common input port of PBS1. The other output port of the optical splitter is connected to the input port of the polarization controller PC2. The output port of PC2 is connected to the common input port of PBS2.

[0009] Furthermore, the polarization multiplexing dual parallel Mach-Zehnder modulator PDM-DPMZM includes:

[0010] A Y-shaped optical splitter, dual parallel Mach-Zehnder modulators X-DPMZM and Y-DPMZM, a 90-degree polarization rotator PR, and a polarization beam combiner PBC. Inside the X-DPMZM, there are two parallel sub-modulators Xa and Xb. Inside the Y-DPMZM, there are two parallel sub-modulators Ya and Yb. The optical signal output by the Y-DPMZM undergoes a 90° polarization rotation through the PR, and then is jointly input into the PBC together with the optical signal output by the X-DPMZM. After the optical signals are combined in the PBC into a polarization multiplexed signal, they are output from the optical output port of the PDM-DPMZM modulator.

[0011] Furthermore, the X-DPMZM is used to modulate the target echo signals at different angles received by the receiving antenna 2 and the receiving antenna 3, and the Y-DPMZM is used to modulate the target echo signal received by the receiving antenna 1 and the local transmission signal respectively.

[0012] Furthermore, the sub-modulators Xa, Xb, Ya, and Yb all operate at the minimum point.

[0013] Furthermore, the modulators X-DPMZM and Y-DPMZM both operate at the quadrature point.

[0014] A method for simultaneously measuring the two-dimensional angle of arrival and Doppler frequency shift of microwaves and photons, based on the device for simultaneously measuring the two-dimensional angle of arrival and Doppler frequency shift of microwaves and photons described in any one of the above, includes the following steps:

[0015] The Doppler frequency shift value is obtained by beating the echo signal and the local reference signal and observing the magnitude of the desired intermediate frequency signal; based on the L-shaped antenna array architecture, a dual-channel down-conversion is used to construct a dual-channel phase-relative voltage mapping relationship, and then the measurements of the azimuth angle and the elevation angle are obtained simultaneously.

[0016] Further, the method of obtaining the Doppler frequency shift value by beating the echo signal and the local reference signal and observing the magnitude of the desired intermediate frequency signal; based on the L-shaped antenna array architecture, using dual-channel down-conversion to construct a dual-channel phase-relative voltage mapping relationship, and then obtaining the measurements of the azimuth angle and the elevation angle simultaneously, specifically includes the following sub-steps:

[0017] First, let the expressions of the three echo signals and the local reference signal be:

[0018]

[0019] V t (t) = V t cos(ω t t) (2);

[0020] Among them, V e1 , V e2 , V e3 and V t respectively represent the amplitudes of echo signal 1, echo signal 2, echo signal 3 and the local reference signal; and respectively represent the phases of echo signal 1, echo signal 2 and echo signal 3; ω e and ω t respectively represent the angular frequencies of the echo signal and the transmitted signal;

[0021] Let the expression of the output signal of the laser be:

[0022]

[0023] Among them, E c represents the optical field amplitude of the laser signal, and ω c represents the angular frequency of the laser signal;

[0024] The expression of the polarization multiplexed optical signal output by the PDM-DPMZM is expressed as:

[0025]

[0026] Among them, E c (t) is the output signal of the laser; μ is the insertion loss of the PDM-DPMZM; m1, m2, m3 and m t are the modulation indices of echo signal 1, echo signal 2, echo signal 3 and the transmitted signal respectively; Jn (·) represents the first kind of Bessel function of order n. Under small-signal input, other high-order components are ignored; and represent the unit vectors of the TE mode and TM mode of the optical field respectively;

[0027] The above signal is input into the corresponding polarization controller and polarization beam splitter after passing through an equal optical splitter;

[0028] Among them, the output signal of PBS1 is written as:

[0029]

[0030] where α is the polarization control angle of the PC; δ is the phase difference between the two polarization multiplexed lights;

[0031] Subsequently, the output signal of PBS1 is input into BPD1 for optoelectronic detection;

[0032] (1) When α = π / 4 and δ = 0:

[0033]

[0034] where η represents the responsivity of the optoelectronic detector; according to formula (6), when the emission signal frequency is known, the value of the Doppler frequency shift, i.e., DFS, is obtained on the spectrum ω = ω e -ω t ; in addition, according to the mapping relationship between phase and DC voltage and the DC signal power, 2ω e the phase difference between the received signals of receiving antenna 1 and receiving antenna 2 is obtained as:

[0035]

[0036] where V DC12 is the DC signal voltage obtained after the beat of the echo signal 1 received by receiving antenna 1 and the echo signal 2 received by receiving antenna 2, and V 2ωe_12 is the voltage of the second harmonic signal obtained after the beat of the echo signal 1 received by receiving antenna 1 and the echo signal 2 received by receiving antenna 2. The arrival angle is solved by using the ratio of DC to harmonic voltage;

[0037] (2) When α = π / 4 and δ = π / 2:

[0038]

[0039] According to formula (8), the value of DFS can be verified again; meanwhile, the cosine phase difference between the received signals of receiving antenna 1 and receiving antenna 3 is expressed as:

[0040]

[0041] Among them, V DC13 is the DC signal voltage obtained after beating the echo signal 1 received by receiving antenna 1 and the echo signal 3 received by receiving antenna 3, and V 2ωe_13 is the voltage of the second harmonic signal obtained after beating the echo signal 1 received by receiving antenna 1 and the echo signal 3 received by receiving antenna 3;

[0042] Then, according to the L-shaped antenna architecture, the phase difference between the echo signals received by receiving antenna 1 and receiving antenna 2 is known to be The phase difference between the echo signals received by receiving antenna 1 and receiving antenna 3 is Then the angles θ X and θ Y between the target point and the X-axis and Y-axis are represented by and as follows:

[0043]

[0044] Among them, d is the antenna placement spacing, and λ is the signal wavelength;

[0045] Finally, combining the trigonometric function relationship, the elevation angle and azimuth angle of the target point are respectively:

[0046]

[0047] The beneficial effects of the present invention include:

[0048] In terms of DFS measurement, the device of the present invention can obtain the DFS value by beating the echo signal and the local reference signal and observing the magnitude of the desired intermediate frequency (IF) signal. In terms of two-dimensional AOA measurement, the device of the present invention is based on the L-shaped antenna array architecture, constructs a dual-channel phase-relative voltage mapping relationship through dual-channel down-conversion, and then obtains the measurement of the azimuth angle and elevation angle simultaneously. Further, the present invention is based on optical quadrature modulation with DC bias control, and the echo signals of the three paths do not affect each other with the transmitted signal, effectively reducing system spurs. The optical quadrature demodulation based on polarization control constructs independent dual down-conversion channels, increasing the measurement dimension of the angle of arrival while measuring the Doppler frequency shift. In addition, the mapping relationship of phase-relative DC voltage adopted by the present invention eliminates the power fluctuation error in the measurement process of the traditional absolute voltage mapping relationship. The structure of the present invention is simple and highly practical, and can be widely applied to military reconnaissance, target tracking, intelligent transportation, unmanned driving and other applications. Description of the Drawings

[0049] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0050] Figure 1 It is a diagram of a microwave photonic two-dimensional angle of arrival and Doppler frequency shift simultaneous measurement device;

[0051] Figure 2 It is a diagram of the two-dimensional angle of arrival test relationship based on an L-shaped antenna;

[0052] Figure 3 It is a two-channel spectrogram (a) Channel 1, receiving antenna 2 - receiving antenna 1; (b) Channel 2, receiving antenna 3 - receiving antenna 1;

[0053] Figure 4 It is the correlation relationship of Channel 1;

[0054] Figure 5 It is the correlation relationship of Channel 2;

[0055] Figure 6 It is the elevation angle θ P varying with θ X and θ Y variation relationship;

[0056] Figure 7 It is the azimuth angle θ A varying with θ X and θ Y variation relationship. Specific implementation manners

[0057] All features disclosed in all embodiments in this specification, or all steps in the methods or processes implicitly disclosed, except for mutually exclusive features and / or steps, can be combined and / or extended, replaced in any way.

[0058] The specific implementation process of the present invention is as follows:

[0059] In the first aspect, as Figure 1As shown in the figure, the present invention provides a microwave photon two-dimensional angle of arrival and Doppler frequency shift simultaneous measurement device, including: a laser diode (LD), a polarization division multiplexing dual-parallel Mach-Zehnder modulator (PDM-DPMZM), an optical splitter, two polarization controllers (PCs), two polarization beam splitters (PBSs), and two balanced photodetectors (BPDs). The output port of the laser is connected to the optical input port of the PDM-DPMZM, the optical output port of the PDM-DPMZM is connected to the common input terminal of the optical splitter, the output port 1 of the optical splitter is connected to the common input port of PBS1, and the two output ports of PBS1 are respectively connected to the two optical input ports of BPD1; the output port 2 of the optical splitter is connected to the common input port of PBS2, and the two output ports of PBS2 are respectively connected to the two optical input ports of BPD2.

[0060] Among them, the PDM-DPMZM is composed of a Y-shaped optical splitter, two parallel DPMZMs (denoted as X-DPMZM and Y-DPMZM), a 90-degree polarization rotator (PR), and a polarization beam combiner (PBC). The X-DPMZM internally contains two parallel sub-modulators (denoted as Xa and Xb), the Y-DPMZM internally contains two parallel sub-modulators (denoted as Ya and Yb), the optical signal output by the Y-DPMZM undergoes a 90° polarization rotation through the PR, and then is jointly input to the PBC together with the optical signal output by the X-DPMZM. After the optical signals are combined in the PBC to form a polarization multiplexed signal, they are output from the PDM-DPMZM modulator.

[0061] Among them, the X-DPMZM is used to modulate the target echo signals received by receiving antenna 2 and receiving antenna 3 at different angles, and the Y-DPMZM respectively modulates the target echo signal received by receiving antenna 1 and the local transmission signal. In order to improve the modulation efficiency, all sub-modulators (Xa, Xb, Ya, and Yb) operate at the minimum point. At the same time, in order to ensure that the three received signals and the transmission signal do not affect each other during the modulation process, all main modulators (X-DPMZM and Y-DPMZM) operate at the quadrature point.

[0062] The working process of the above device is as follows: Assume that the expressions of the three-way echo signals and the local reference signal are respectively:

[0063]

[0064] V t (t) = V t cos(ω t t) (2);

[0065] Among them, V e1 , V e2 , V e3 and V t respectively represent the amplitudes of echo signal 1, echo signal 2, echo signal 3, and the local reference signal; and respectively represent the phases of echo signal 1, echo signal 2, and echo signal 3; ω e and ω t respectively represent the angular frequencies of the echo signal and the transmitted signal.

[0066] Assume that the expression of the continuous laser signal output by the laser is:

[0067]

[0068] Among them, E c represents the optical field amplitude of the laser signal, and ω c represents the angular frequency of the laser signal.

[0069] According to the system structure settings shown in Appendix Figure 1 , the expression of the polarization multiplexed optical signal output by the PDM-DPMZM can be expressed as:

[0070]

[0071] Among them, μ is the insertion loss of the PDM-DPMZM; m1, m2, m3, and m t are respectively the modulation indices of echo signal 1, echo signal 2, echo signal 3, and the transmitted signal; J n (·) represents the first kind of Bessel function of order n. Under small-signal input, other high-order components are ignored; and respectively represent the unit vectors of the TE mode and TM mode of the optical field.

[0072] Next, the above signal is input into the PC and PBS after passing through an equal optical splitter. Taking PBS1 as an example, its output signal can be written as:

[0073]

[0074] Among them, α is the polarization control angle of the PC; δ is the phase difference between the two polarization multiplexed optical signals. Subsequently, the output signal of PBS1 is input into BPD1 for optoelectronic detection.

[0075] (1) When α = π / 4 and δ = 0

[0076]

[0077] Among them, η represents the responsivity of the photodetector. It can be found from Equation (6) that when the transmission signal frequency is known, the value of the Doppler frequency shift, i.e., DFS, can be obtained on the spectrum ω = ω e -ω t . In addition, the phase difference between the received signals of receiving antenna 1 and receiving antenna 2 can also be obtained according to the phase-DC voltage mapping relationship and the DC signal power and 2ω e signal power:

[0078]

[0079] Different from the traditional angle-of-arrival measurement method based on the phase-DC voltage mapping relationship, here the ratio of DC to harmonic voltage is used to solve the angle of arrival, eliminating the measurement error caused by power fluctuations in the process of solving the absolute voltage value.

[0080] (2) When α = π / 4 and δ = π / 2

[0081]

[0082] Similarly, the value of DFS can be verified again. At the same time, the cosine phase difference between the received signals of receiving antenna 1 and receiving antenna 3 can be expressed as:

[0083]

[0084] Finally, according to the existing L-shaped antenna architecture scheme shown in the appendix Figure 2 , the phase difference between the echo signals received by antenna 1 and antenna 2 is known as the phase difference between the echo signals received by antenna 1 and antenna 3 is then the angles θ X and θ Y between the target point and the X-axis and Y-axis can be and expressed as:

[0085]

[0086] Among them, d is the antenna placement spacing and λ is the signal wavelength. Finally, combining trigonometric function relationships, the elevation angle and azimuth angle of the target point can be obtained as:

[0087]

[0088] In other preferred embodiments, a system based on the above-mentioned microwave photon two-dimensional angle of arrival and Doppler frequency shift simultaneous measurement device provided by the present invention specifically includes: a laser, a signal source 1, a signal source 2, a signal source 3, a signal source 4, a spectrum analyzer, a power meter, a PDM-DPMZM, an optical splitter, PC1, PC2, PBS1, PBS2, BPD1, and BPD2. The output end of the tunable laser is connected to the optical input port of the PDM-DPMZM, and the output port of the PDM-DPMZM is connected to the common input port of the optical splitter; the output port 1 of the optical splitter is connected to the input port of PC1, and the output port of PC1 is connected to the common input port of PBS1; the output port 1 of PBS1 is connected to the first optical input port of BPD1, and the output port 2 of PBS1 is connected to the second optical input port of BPD1; the output port 2 of the optical splitter is connected to the input port of PC2, and the output port of PC2 is connected to the common input port of PBS2; the output port 1 of PBS2 is connected to the first optical input port of BPD2, and the output port 2 of PBS2 is connected to the second optical input port of BPD2; the output electrical signals of BPD1 and BPD2 are connected to the power meter.

[0089] In other preferred embodiments, the present invention provides a method for simultaneously measuring the two-dimensional angle of arrival and Doppler frequency shift of microwave photons, including the following steps:

[0090] Step 1: The laser generates an optical carrier with a working frequency of 193.1 THz and an optical power of 16 dBm; the radio frequency signal sources 1, 2, and 3 generate radio frequency signals with a frequency of 15.5 GHz, a power of 0 dBm, and an initial phase of 0°; the radio frequency signal source 4 generates a local emission signal with a frequency of 15 GHz and a power of 10 dBm; the half-wave voltage of the PDM-DPMZM is 3.5 V, and the extinction ratio is 35 dB; the responsivity of the PD is 0.75 A / W.

[0091] Step 2: Based on the parameter settings in Step 1, adjust PC1 so that α = π / 4 and δ = 0, and obtain the output spectrum of BPD1 as shown in Figure 3 (a). It can be found that a signal spectral line with a frequency of 0.5 GHz appears on the right side of the DC component, indicating that the received signal of antenna 2 has a frequency difference of 0.5 GHz from the local emission signal; then, adjust PC2 so that α = π / 4 and δ = π / 2, and obtain the output spectrum of BPD2 as shown in Figure 3 (b). It can be found that a signal spectral line with a frequency of 0.5 GHz also appears on the right side of the DC component, indicating that the received signal of antenna 3 has a frequency difference of 0.5 GHz from the local emission signal. Considering comprehensively, it can be considered that the Doppler frequency shift of the target signal is 0.5 GHz.

[0092] Step 3: Remove the local transmission signal loaded on the Y-DPMZM sub-modulator Ya and make it no-load; set the phase of the RF signal generated by the RF signal source 2 to continuously vary between 0 and 180°, and adjust PC1 so that , measure the signal power at the DC and the second harmonic of the received signal respectively, as Figure 4 shown. It can be found that the DC signal power changes with the phase difference between antenna 1 and antenna 2, and there is a notch point around 90°, while the signal power at the second harmonic of the received signal remains basically unchanged. Based on this set of data, solve the phase difference according to formula (7), and the phase discrimination situation obtained is as Figure 4 shown by the data on the right in. It can be found that the phase discrimination curve also has an extreme point at 90°, which indicates that the phase discrimination range of this method is 0 to 90°. In addition, by comparing Figure 4 the abscissa of and the data on the right, it can be obtained that the phase discrimination error is less than 0.4°.

[0093] Step 4: Keep the sub-modulator Ya no-load and other settings unchanged, set the phase of the RF signal generated by the RF signal source 3 to continuously vary between 0 and 180°, and adjust PC2 so that α = π / 4 and δ = π / 2, measure the signal power at the DC and the second harmonic of the received signal respectively, as Figure 5 shown, and the same conclusion as in Step 3 can be obtained.

[0094] Step 5: According to formula (10), formula (11) and Figure 2 , the elevation angle and azimuth angle information of the target S can be calculated, as Figure 6 and Figure 7 shown. It can be found that the elevation angle range that this method can measure is about 45° to 90°, and the azimuth angle range is about 30° to 60°.

[0095] In summary, the present invention constructs a microwave photon two-dimensional angle of arrival and Doppler frequency shift simultaneous measurement scheme, realizes dual-channel down-conversion through optical quadrature modulation and quadrature demodulation method based on polarization control technology, measures the Doppler frequency shift on this basis, and obtains double frequency verification. In addition, under the L-shaped antenna architecture, measure one-dimensional AOA based on the phase-relative voltage mapping relationship, and then the two-dimensional positioning of the target can be realized by measuring two one-dimensional angles of arrival, and the elevation angle and azimuth angle are measured. This scheme has a simple structure and flexible operation, and has potential application value in electronic systems such as phased array radars and beamforming networks.

[0096] The above-described embodiments are only examples of the present invention and are not intended to limit the protection scope of the present invention only. It should be noted that for those of ordinary skill in the art, several equivalent deformations and substitutions can be made on the basis of the content disclosed in the present invention. Types such as modulator type, laser type, received signal frequency, local transmitted signal frequency, optical carrier frequency, optical carrier power, received signal power, local transmitted signal power, DC bias angle of the modulator, polarization control angle, adjustable phase difference, etc. can all be changed. These equivalent deformations, substitutions, and adjustments of the frequency range should also be regarded as the protection scope of the present invention.

Claims

1. A microwave photon two-dimensional angle of arrival and Doppler frequency shift simultaneous measurement device, characterized in that Including: A laser, a polarization multiplexing dual parallel Mach-Zehnder modulator PDM-DPMZM, an optical splitter, two polarization beam splitters PBS, and two balanced photodetectors BPD; The output port of the laser is connected to the optical input port of the PDM-DPMZM, the optical output port of the PDM-DPMZM is connected to the common input end of the optical splitter, the output port one of the optical splitter is connected to the common input port of the first polarization beam splitter PBS1, and the two output ports of PBS1 are respectively connected to the two optical input ports of the first balanced photodetector BPD1; the output port two of the optical splitter is connected to the common input port of the second polarization beam splitter PBS2, and the two output ports of PBS2 are respectively connected to the two optical input ports of the second balanced photodetector BPD2.

2. The microwave photon two-dimensional angle of arrival and Doppler frequency shift simultaneous measurement device according to claim 1, characterized in that, It further includes two polarization controllers PC. The output port one of the optical splitter is connected to the input port of the first polarization controller PC1, and the output port of PC1 is connected to the common input port of PBS1; the output port two of the optical splitter is connected to the input port of the second polarization controller PC2, and the output port of PC2 is connected to the common input port of PBS2.

3. The microwave photon two-dimensional angle of arrival and Doppler frequency shift simultaneous measurement device according to claim 1, wherein The polarization multiplexing dual parallel Mach-Zehnder modulator PDM-DPMZM includes: A Y-shaped optical splitter, dual parallel Mach-Zehnder modulators X-DPMZM and Y-DPMZM, a 90-degree polarization rotator PR, and a polarization beam combiner PBC; two parallel sub-modulators Xa and Xb are included inside the X-DPMZM, two parallel sub-modulators Ya and Yb are included inside the Y-DPMZM, the optical signal output by the Y-DPMZM undergoes a 90° polarization rotation through the PR, and then is jointly input to the PBC together with the optical signal output by the X-DPMZM. After the optical signals are combined in the PBC to form a polarization multiplexed signal, it is output from the optical output port of the PDM-DPMZM modulator.

4. The microwave photon two-dimensional angle of arrival and Doppler frequency shift simultaneous measurement device according to claim 3, characterized in that, The X-DPMZM is used to modulate the target echo signals received by the receiving antenna 2 and the receiving antenna 3 at different angles, and the Y-DPMZM is used to modulate the target echo signal received by the receiving antenna 1 and the local transmission signal respectively.

5. The microwave photon two-dimensional angle of arrival and Doppler frequency shift simultaneous measurement device according to claim 3, characterized in that, The sub-modulators Xa, Xb, Ya, and Yb all operate at the minimum point.

6. The microwave photon two-dimensional angle of arrival and Doppler frequency shift simultaneous measurement device according to claim 3, wherein The modulators X-DPMZM and Y-DPMZM both operate at the quadrature point.

7. A method for simultaneously measuring two-dimensional angle of arrival and Doppler frequency shift of microwave photons, characterized in that, Based on the microwave photon two-dimensional angle of arrival and Doppler frequency shift simultaneous measurement device according to any one of claims 2 to 6, it includes the following steps: By beating the echo signal and the local reference signal, observing the magnitude of the desired intermediate frequency signal to obtain the value of the Doppler frequency shift; and then based on the L-shaped antenna array architecture, constructing a two-channel phase relative voltage mapping relationship through two-channel down-conversion, thereby simultaneously obtaining the measurements of the azimuth angle and the elevation angle.

8. The method for simultaneously measuring the two-dimensional angle of arrival and Doppler frequency shift of microwave photons according to claim 7, wherein The step of obtaining the value of the Doppler frequency shift by beating the echo signal and the local reference signal, observing the magnitude of the desired intermediate frequency signal; and then based on the L-shaped antenna array architecture, constructing a two-channel phase relative voltage mapping relationship through two-channel down-conversion, thereby simultaneously obtaining the measurements of the azimuth angle and the elevation angle specifically includes the following sub-steps: First, assume that the expressions of the three-way echo signal and the local reference signal are respectively: V t V(t)=V t cos(ω t t) (2); Among them, V e1 , V e2 , V e3 and V t respectively represent the amplitudes of echo signal 1, echo signal 2, echo signal 3 and the local reference signal; and respectively represent the phases of echo signal 1, echo signal 2 and echo signal 3; ω e and ω t respectively represent the angular frequencies of the echo signal and the transmitted signal; Assume that the expression of the output signal of the laser is: Among them, E c represents the optical field amplitude of the laser signal, and ω c represents the angular frequency of the laser signal; The expression of the polarization multiplexed optical signal output by the PDM-DPMZM is expressed as: Among them, E c (t) is the output signal of the laser; μ is the insertion loss of the PDM-DPMZM; m1, m2, m3, and m t are the modulation indices of echo signal 1, echo signal 2, echo signal 3, and the transmitted signal, respectively; J n (·) represents the Bessel function of the first kind of order n. Under small-signal input, other higher-order components are ignored; and represent the unit vectors of the TE mode and TM mode of the optical field, respectively; The above signal is input into the corresponding polarization controller and polarization beam splitter after passing through an equal-division optical splitter; Among them, the output signal of PBS1 is written as: Among them, α is the polarization control angle of the PC; δ is the phase difference between the two polarization multiplexed optical signals; Subsequently, the output signal of PBS1 is input into BPD1 for photoelectric detection; (1) When α = π / 4 and δ = 0: Among them, η represents the responsivity of the photodetector; according to formula (6), when the emission signal frequency is known, the value of the Doppler frequency shift, i.e., DFS, can be obtained on the spectrum ω = ω e - ω t ; in addition, according to the mapping relationship between phase and DC voltage and the DC signal power, 2ω e signal power, the phase difference between the received signals of receiving antenna 1 and receiving antenna 2 is obtained as follows: Among them, V DC12 is the DC signal voltage obtained after the beat of the echo signal 1 received by the receiving antenna 1 and the echo signal 2 received by the receiving antenna 2. is the voltage of the second harmonic signal obtained after the beat of the echo signal 1 received by the receiving antenna 1 and the echo signal 2 received by the receiving antenna 2. The arrival angle is solved by using the ratio of the DC voltage to the harmonic voltage. (2) When α = π / 4 and δ = π / 2: According to formula (8), the value of DFS can be verified again; meanwhile, the cosine phase difference between the received signals of receiving antenna 1 and receiving antenna 3 is expressed as: Among them, V DC13 is the DC signal voltage obtained after the beat of the echo signal 1 received by the receiving antenna 1 and the echo signal 3 received by the receiving antenna 3; is the voltage of the second harmonic signal obtained after the beat of the echo signal 1 received by the receiving antenna 1 and the echo signal 3 received by the receiving antenna 3; Then, according to the L-shaped antenna architecture, the phase difference between the echo signals received by the receiving antenna 1 and the receiving antenna 2 is The phase difference between the echo signals received by the receiving antenna 1 and the receiving antenna 3 is Then the angles θ X and θ Y of the target point with respect to the X-axis and the Y-axis are represented by and as follows: Among them, d is the antenna placement spacing, and λ is the signal wavelength; Finally, combining the trigonometric function relationship, the elevation angle and azimuth angle of the target point are respectively:

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