Radar time-frequency synchronization device and method

Abstract

The embodiment of the invention discloses a radar time-frequency synchronization device and method. In one specific implementation mode, the device comprises an electric signal unit used for amplifying a first synchronizing signal and a first reference signal to obtain a second synchronizing signal and a second reference signal, amplifying a third synchronizing signal to obtain a fourth synchronizing signal, and outputting the fourth synchronizing signal to the second reference signal; performing phase discrimination on the third reference signal and the first reference signal to obtain a phase difference signal; the optical transceiver unit is used for converting and combining the second synchronizing signal and the second reference signal to obtain a third optical signal, and separating and converting the fourth optical signal to obtain a third reference signal and a third synchronizing signal; and the optical transmission unit is used for transmitting the third optical signal and adjusting the third optical signal according to the phase difference signal to obtain a fourth optical signal.

Description

Technical Field

[0001] This invention relates to the field of time and frequency signal synchronization. More specifically, it relates to a radar time and frequency synchronization device and method. Background Technology

[0002] Currently, compared to monostatic radar, the primary technical challenge of distributed fully coherent radar is the synchronization of time and phase between individual radar units. According to relevant literature, achieving distributed transceiver coherence requires a phase synchronization accuracy on the order of picoseconds. This accuracy comprises two parts: a fixed delay in the transmission of the reference signal between the two stations, and phase fluctuations in the reference signal during transmission. The fixed delay is related to the transmission distance and can be corrected using formulas; this invention primarily addresses phase fluctuations during transmission. Summary of the Invention

[0003] The purpose of this invention is to provide a radar time-frequency synchronization device and method to solve at least one of the problems existing in the prior art.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: The first aspect of the present invention provides a radar time-frequency synchronization device, comprising: An electrical signal unit is used to amplify the first synchronization signal and the first reference signal to obtain the second synchronization signal and the second reference signal, and to amplify the third synchronization signal to obtain the fourth synchronization signal, and to perform phase detection on the third reference signal and the first reference signal to obtain the phase difference signal; The optical transceiver unit is used to convert and combine the second synchronization signal and the second reference signal to obtain the third optical signal, and to separate and convert the fourth optical signal to obtain the third reference signal and the third synchronization signal. An optical transmission unit is used to transmit a third optical signal and adjust the third optical signal according to a phase difference signal to obtain a fourth optical signal.

[0005] Optionally, the first input terminal of the electrical signal unit receives the first synchronization signal; The second input terminal of the electrical signal unit receives the first reference signal; The third input terminal of the electrical signal unit receives the first reference signal; The fourth input terminal of the electrical signal unit is connected to the first output terminal of the optical transceiver unit; The fifth input terminal of the electrical signal unit is connected to the second output terminal of the optical transceiver unit; The first output terminal of the electrical signal unit is connected to the first input terminal of the optical transceiver unit; The second output terminal of the electrical signal unit is connected to the second input terminal of the optical transceiver unit; The third output terminal of the electrical signal unit outputs the fourth synchronization signal; The fourth output terminal of the electrical signal unit is connected to the first input terminal of the optical transmission unit; The third output terminal of the optical transceiver unit is connected to the second input terminal of the optical transmission unit; The third input terminal of the optical transceiver unit is connected to the output terminal of the optical transmission unit.

[0006] Optionally, the electrical signal unit includes a first signal amplifier, a second signal amplifier, a third signal amplifier, and a phase detector; The first signal amplifier is used to amplify the power of the first synchronization signal to obtain the second synchronization signal; The second signal amplifier is used to amplify the power of the first reference signal to obtain the second reference signal; The third signal amplifier is used to amplify the power of the third synchronization signal to obtain the fourth synchronization signal; The phase detector is used to perform phase detection on the third reference signal and the first reference signal to obtain the phase difference signal.

[0007] Optionally, the optical transceiver unit includes a first laser, a second laser, a first wavelength division multiplexer, a first detector, a second detector, and a second wavelength division multiplexer; The first laser is used to convert the second synchronization signal into a first optical signal; The second laser is used to convert the second reference signal into a second optical signal; The first wavelength division multiplexer is used to combine the first optical signal and the second optical signal into the third optical signal; The second wavelength division multiplexer is used to divide the fourth optical signal into a fifth optical signal and a sixth optical signal; The first detector is used to convert the fifth optical signal into the third reference signal; The second detector is used to convert the sixth optical signal into the third synchronization signal.

[0008] Optionally, the optical transmission unit includes an optical fiber and an adjustable optical delay line; The optical fiber is used to transmit the third optical signal; The adjustable optical delay line is used to adjust the phase of the third optical signal according to the phase difference signal to obtain the fourth optical signal.

[0009] Optionally, the input terminal of the first signal amplifier receives the first synchronization signal, and the output terminal of the first signal amplifier outputs the second synchronization signal; The input terminal of the second signal amplifier receives the first reference signal, and the output terminal of the second signal amplifier outputs the second reference signal; The input terminal of the third signal amplifier receives the third synchronization signal, and the output terminal of the third signal amplifier outputs the fourth synchronization signal. The first input terminal of the phase detector receives the first reference signal, the second input terminal of the phase detector receives the third reference signal, and the output terminal of the phase detector outputs the phase difference signal.

[0010] Optionally, the input terminal of the first laser receives the second synchronization signal, and the output terminal of the first laser outputs the first optical signal; The input terminal of the second laser receives the second reference signal, and the output terminal of the second laser outputs the second optical signal; The first input terminal of the first wavelength division multiplexer receives the first optical signal, the second input terminal of the first wavelength division multiplexer receives the second optical signal, and the output terminal of the first wavelength division multiplexer outputs the third optical signal. The input terminal of the second wavelength division multiplexer receives the fourth optical signal, the first output terminal of the second wavelength division multiplexer outputs the fifth optical signal, and the second output terminal of the second wavelength division multiplexer outputs the sixth optical signal. The input terminal of the first detector receives the fifth optical signal, and the output terminal of the first detector outputs the third reference signal; The input terminal of the second detector receives the sixth optical signal, and the output terminal of the second detector receives the third synchronization signal.

[0011] Optionally, the input end of the optical fiber receives the third optical signal, and the output end of the optical fiber outputs the third optical signal; The first input terminal of the adjustable optical delay line receives the phase difference signal, the second input terminal of the adjustable optical delay line receives the third optical signal, and the output terminal of the adjustable optical delay line outputs the fourth optical signal.

[0012] Optionally, the length of the optical fiber is less than or equal to 10 km.

[0013] A second aspect of the present invention provides a radar time-frequency synchronization method, comprising: The first synchronization signal and the first reference signal are amplified by an electrical signal unit to obtain the second synchronization signal and the second reference signal, and the third synchronization signal is amplified to obtain the fourth synchronization signal. The third reference signal and the first reference signal are phase-discriminated to obtain the phase difference signal. The optical transceiver unit converts and combines the second synchronization signal and the second reference signal to obtain the third optical signal, and separates and converts the fourth optical signal to obtain the third reference signal and the third synchronization signal. The third optical signal is transmitted using an optical transmission unit, and the fourth optical signal is obtained by adjusting the third optical signal according to the phase difference signal.

[0014] The beneficial effects of this invention are as follows: The technical solution described in this invention amplifies the power of the synchronization signal and the reference signal through an electrical signal unit, and performs phase detection on the reference signal and the transmitted reference signal to obtain the phase difference. This is then converted into an optical signal by an optical transceiver unit, passed through an optical transmission unit, where the phase difference signal adjusts the adjustable delay line in the optical transmission unit in real time to adjust the signal phase. The signal is then returned to the optical transceiver unit to be converted back into an electrical signal, and finally output through the electrical signal unit, thus achieving phase synchronization of the signal. This invention utilizes the principle of feedback compensation to compensate for phase fluctuations and fixed delays during long-distance transmission of distributed radar time-frequency signals, achieving long-distance time-frequency signal synchronization for radar. Attached Figure Description

[0015] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0016] Figure 1 A schematic diagram of a radar time-frequency synchronization device provided in one embodiment of the present invention is shown.

[0017] Figure 2 A flowchart of a radar time-frequency synchronization method provided by another embodiment of the present invention is shown. Detailed Implementation

[0018] To more clearly illustrate the present invention, the following description, in conjunction with embodiments and accompanying drawings, further explains the invention. Similar components in the drawings are indicated by the same reference numerals. Those skilled in the art should understand that the specific description below is illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention.

[0019] Currently, compared to monostatic radar, the primary technical challenge of distributed fully coherent radar is the synchronization of time and phase between individual radar units. According to relevant literature, achieving distributed transceiver coherence requires a phase synchronization accuracy on the order of picoseconds. This accuracy comprises two parts: a fixed delay in the transmission of the reference signal between the two stations, and phase fluctuations in the reference signal during transmission. The fixed delay is related to the transmission distance and can be corrected using formulas; this invention primarily addresses phase fluctuations during transmission.

[0020] In view of this, one embodiment of the present invention provides a radar time-frequency synchronization device, comprising: an electrical signal unit for amplifying a first synchronization signal and a first reference signal to obtain a second synchronization signal and a second reference signal, amplifying a third synchronization signal to obtain a fourth synchronization signal, and performing phase detection on the third reference signal and the first reference signal to obtain a phase difference signal; an optical transceiver unit for converting and combining the second synchronization signal and the second reference signal to obtain a third optical signal, and separating and converting the fourth optical signal to obtain a third reference signal and a third synchronization signal; and an optical transmission unit for transmitting the third optical signal and adjusting the third optical signal according to the phase difference signal to obtain a fourth optical signal.

[0021] In a specific example, the device includes: an electrical signal unit for transmitting electrical signals and performing phase detection on the signals; an optical transceiver unit for converting electrical signals and optical signals to each other; and an optical transmission unit for transmitting optical signals over long distances and performing phase adjustment.

[0022] In a specific example, such as Figure 1 As shown, the long-range radar time and frequency synchronization device 11 includes an electrical signal unit 1, an optical transceiver unit 2, and an optical transmission unit 3. The electrical signal unit 1 amplifies the power of external and transmitted synchronization and reference signals, and performs phase detection on the external and transmitted reference signals. The optical transceiver unit 2 consists of two parts: a first electro-optic conversion section converts the externally input synchronization and reference signals into one optical signal, and a second photoelectric conversion section converts the transmitted optical signal back into one synchronization signal and one reference signal. The optical transmission unit 3 is used for long-distance transmission of the optical signal and real-time phase adjustment.

[0023] In this embodiment, the synchronization signal and the reference signal are amplified by an electrical signal unit, and the reference signal and the transmitted reference signal are phase-discriminated to obtain the phase difference. Then, the optical transceiver unit converts it into an optical signal, which passes through an optical transmission unit. The phase difference signal adjusts the adjustable delay line in the optical transmission unit in real time to adjust the phase of the signal. Then, it returns to the optical transceiver unit to be converted into an electrical signal, and finally outputs it through the electrical signal unit, thus realizing the phase synchronization of the signal. This invention utilizes the principle of feedback compensation to compensate for the phase fluctuation and fixed delay in the long-distance transmission of distributed radar time and frequency signals, thereby realizing long-distance time and frequency signal synchronization of radar.

[0024] In one possible implementation, the first input terminal of the electrical signal unit receives the first synchronization signal; the second input terminal of the electrical signal unit receives the first reference signal; the third input terminal of the electrical signal unit receives the first reference signal; the fourth input terminal of the electrical signal unit is connected to the first output terminal of the optical transceiver unit; the fifth input terminal of the electrical signal unit is connected to the second output terminal of the optical transceiver unit; the first output terminal of the electrical signal unit is connected to the first input terminal of the optical transceiver unit; the second output terminal of the electrical signal unit is connected to the second input terminal of the optical transceiver unit; the third output terminal of the electrical signal unit outputs the fourth synchronization signal; the fourth output terminal of the electrical signal unit is connected to the first input terminal of the optical transmission unit; the third output terminal of the optical transceiver unit is connected to the second input terminal of the optical transmission unit; and the third input terminal of the optical transceiver unit is connected to the output terminal of the optical transmission unit.

[0025] In one possible implementation, the electrical signal unit includes a first signal amplifier, a second signal amplifier, a third signal amplifier, and a phase detector; the first signal amplifier is used to amplify the first synchronization signal to obtain a second synchronization signal; the second signal amplifier is used to amplify the first reference signal to obtain a second reference signal; the third signal amplifier is used to amplify the third synchronization signal to obtain a fourth synchronization signal; and the phase detector is used to perform phase detection between the third reference signal and the first reference signal to obtain the phase difference signal.

[0026] In a specific example, such as Figure 1 As shown, the electrical signal unit 1 includes a first signal amplifier 41, a second signal amplifier 42, a third signal amplifier 43, and a phase detector 5. The first signal amplifier 41, the second signal amplifier 42, and the third signal amplifier 43 are used to amplify the power of the external input signal and the transmitted output signal; the phase detector 5 is used to detect the phase difference between the external reference signal and the transmitted reference signal.

[0027] In one possible implementation, the optical transceiver unit includes a first laser, a second laser, a first wavelength division multiplexer, a first detector, a second detector, and a second wavelength division multiplexer; the first laser is used to convert the second synchronization signal into a first optical signal; the second laser is used to convert the second reference signal into a second optical signal; the first wavelength division multiplexer is used to combine the first optical signal and the second optical signal into the third optical signal; the second wavelength division multiplexer is used to divide the fourth optical signal into a fifth optical signal and a sixth optical signal; the first detector is used to convert the fifth optical signal into the third reference signal; and the second detector is used to convert the sixth optical signal into the third synchronization signal.

[0028] In a specific example, such as Figure 1 As shown, the optical transceiver unit 2 comprises two parts: an electro-optical conversion section that converts externally input synchronization and reference signals into one optical signal, and an opto-optical conversion section that converts the transmitted optical signal back into one synchronization signal and one reference signal. The electro-optical conversion section includes a first laser 61, a second laser 62, and a first wavelength division multiplexer 81; the opto-optical conversion section includes a first detector 71, a second detector 72, and a second wavelength division multiplexer 82. The first laser 61 and the second laser 62 are used to convert the synchronization and reference signals from electrical signals to optical signals. The first detector 71 and the second detector 72 are used to convert the synchronization and reference signals from optical signals to electrical signals. The first wavelength division multiplexer 81 is used to combine optical signals of different wavelengths into one optical fiber for transmission, and the second wavelength division multiplexer 82 separates optical signals of different wavelengths into two optical fibers for transmission.

[0029] In one possible implementation, the optical transmission unit includes an optical fiber and an adjustable optical delay line; the optical fiber is used to transmit the third optical signal; the adjustable optical delay line is used to adjust the phase of the third optical signal according to the phase difference signal to obtain the fourth optical signal.

[0030] In a specific example, such as Figure 1 As shown, the optical transmission unit 3 includes a long-distance transmission optical fiber 9 and an adjustable optical delay line 10, which transmits optical signals over long distances and adjusts their phase in real time.

[0031] In one possible implementation, the input terminal of the first signal amplifier receives the first synchronization signal, and the output terminal of the first signal amplifier outputs the second synchronization signal; the input terminal of the second signal amplifier receives the first reference signal, and the output terminal of the second signal amplifier outputs the second reference signal; the input terminal of the third signal amplifier receives the third synchronization signal, and the output terminal of the third signal amplifier outputs the fourth synchronization signal; the first input terminal of the phase detector receives the first reference signal, the second input terminal of the phase detector receives the third reference signal, and the output terminal of the phase detector outputs the phase difference signal.

[0032] In a specific example, such as Figure 1 As shown, the first terminals of the first signal amplifier 41 and the second signal amplifier 42 are connected to the outside, the first terminal of the third signal amplifier 43 is connected to the input of the transmitted signal, the second terminal of the third signal amplifier 43 is connected to the outside, and the second terminals of the first signal amplifier 41 and the second signal amplifier 42 are connected to the output of the transmitted signal; the first terminal and the second terminal of the phase detector 5 are respectively connected to the external input reference signal and the transmitted reference signal, and the phase difference between the two is output at the third terminal.

[0033] In one possible implementation, the input terminal of the first laser receives the second synchronization signal, and the output terminal of the first laser outputs the first optical signal; the input terminal of the second laser receives the second reference signal, and the output terminal of the second laser outputs the second optical signal; the first input terminal of the first wavelength division multiplexer receives the first optical signal, the second input terminal of the first wavelength division multiplexer receives the second optical signal, and the output terminal of the first wavelength division multiplexer outputs the third optical signal; the input terminal of the second wavelength division multiplexer receives the fourth optical signal, the first output terminal of the second wavelength division multiplexer outputs the fifth optical signal, and the second output terminal of the second wavelength division multiplexer outputs the sixth optical signal; the input terminal of the first detector receives the fifth optical signal, and the output terminal of the first detector outputs the third reference signal; the input terminal of the second detector receives the sixth optical signal, and the output terminal of the second detector outputs the third synchronization signal.

[0034] In a specific example, such as Figure 1 As shown, the first ends of the first laser 61 and the second laser 62 are connected to the amplified synchronization signal and the reference signal; the first and second ends of the first wavelength division multiplexer 81 are respectively connected to the second ends of the first laser 61 and the second laser 62, and the third end of the first wavelength division multiplexer 81 is connected to the first end of the optical transmission unit. In a specific example, such as Figure 1As shown, the third terminal of the second wavelength division multiplexer 82 is connected to the second terminal of the optical transmission unit, and the first and second terminals of the second wavelength division multiplexer 82 are connected to the first terminals of the first detector 71 and the first detector 72; the second terminals of the first detector 71 and the first detector 72 are respectively connected to the synchronization signal and the reference signal that will be amplified in power.

[0035] In one possible implementation, the input end of the optical fiber receives the third optical signal, and the output end of the optical fiber outputs the third optical signal; the first input end of the adjustable optical delay line receives the phase difference signal, the second input end of the adjustable optical delay line receives the third optical signal, and the output end of the adjustable optical delay line outputs the fourth optical signal.

[0036] In a specific example, such as Figure 1 As shown, the first end of the long-distance optical fiber 9 is connected to the optical transceiver unit 2 for long-distance transmission of optical signals; the first end of the adjustable delay line 10 is connected to the second end of the long-distance optical fiber 9, and the phase difference signal generated by the phase detector 5 of the electrical signal unit 1 is used to adjust the phase of the transmitted optical signal in real time.

[0037] In one possible implementation, the length of the optical fiber is less than or equal to 10 km.

[0038] Another embodiment of the present invention provides a radar time-frequency synchronization method, comprising: amplifying a first synchronization signal and a first reference signal using an electrical signal unit to obtain a second synchronization signal and a second reference signal, amplifying a third synchronization signal to obtain a fourth synchronization signal, and performing phase detection on the third reference signal and the first reference signal to obtain a phase difference signal; converting and combining the second synchronization signal and the second reference signal using an optical transceiver unit to obtain a third optical signal, and separating and converting the fourth optical signal to obtain a third reference signal and a third synchronization signal; transmitting the third optical signal using an optical transmission unit, and adjusting the third optical signal according to the phase difference signal to obtain a fourth optical signal.

[0039] In a specific example, such as Figure 2 As shown, the method includes: S100: Amplifies the power of the signal and performs phase detection on the reference signal and the transmitted reference signal to obtain the phase difference signal.

[0040] S200: Performs electro-optical and photoelectric conversion on the reference signal and synchronization signal.

[0041] S300: Transmits optical signals over long distances and uses phase difference signals to perform real-time phase adjustment of the transmitted signals.

[0042] In this embodiment, the synchronization signal and the reference signal are amplified by an electrical signal unit, and the reference signal and the transmitted reference signal are phase-discriminated to obtain the phase difference. Then, the optical transceiver unit converts it into an optical signal, which passes through an optical transmission unit. The phase difference signal adjusts the adjustable delay line in the optical transmission unit in real time to adjust the phase of the signal. Then, it returns to the optical transceiver unit to be converted into an electrical signal, and finally outputs it through the electrical signal unit, thus realizing the phase synchronization of the signal. This invention utilizes the principle of feedback compensation to compensate for the phase fluctuation and fixed delay in the long-distance transmission of distributed radar time and frequency signals, thereby realizing long-distance time and frequency signal synchronization of radar.

[0043] In the description of this invention, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0044] It should also be noted that in the description of this invention, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0045] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A radar time-frequency synchronization device, characterized in that, include: An electrical signal unit is used to amplify the first synchronization signal and the first reference signal to obtain the second synchronization signal and the second reference signal, and to amplify the third synchronization signal to obtain the fourth synchronization signal, and to perform phase detection on the third reference signal and the first reference signal to obtain the phase difference signal; The optical transceiver unit is used to convert and combine the second synchronization signal and the second reference signal to obtain the third optical signal, and to separate and convert the fourth optical signal to obtain the third reference signal and the third synchronization signal. An optical transmission unit is used to transmit a third optical signal and adjust the third optical signal according to a phase difference signal to obtain a fourth optical signal.

2. The radar time-frequency synchronization device according to claim 1, characterized in that, The first input terminal of the electrical signal unit receives the first synchronization signal; The second input terminal of the electrical signal unit receives the first reference signal; The third input terminal of the electrical signal unit receives the first reference signal; The fourth input terminal of the electrical signal unit is connected to the first output terminal of the optical transceiver unit; The fifth input terminal of the electrical signal unit is connected to the second output terminal of the optical transceiver unit; The first output terminal of the electrical signal unit is connected to the first input terminal of the optical transceiver unit; The second output terminal of the electrical signal unit is connected to the second input terminal of the optical transceiver unit; The third output terminal of the electrical signal unit outputs the fourth synchronization signal; The fourth output terminal of the electrical signal unit is connected to the first input terminal of the optical transmission unit; The third output terminal of the optical transceiver unit is connected to the second input terminal of the optical transmission unit; The third input terminal of the optical transceiver unit is connected to the output terminal of the optical transmission unit.

3. The radar time-frequency synchronization device according to claim 2, characterized in that, The electrical signal unit includes a first signal amplifier, a second signal amplifier, a third signal amplifier, and a phase detector; The first signal amplifier is used to amplify the power of the first synchronization signal to obtain the second synchronization signal; The second signal amplifier is used to amplify the power of the first reference signal to obtain the second reference signal; The third signal amplifier is used to amplify the power of the third synchronization signal to obtain the fourth synchronization signal; The phase detector is used to perform phase detection on the third reference signal and the first reference signal to obtain the phase difference signal.

4. The radar time-frequency synchronization device according to claim 3, characterized in that, The optical transceiver unit includes a first laser, a second laser, a first wavelength division multiplexer, a first detector, a second detector, and a second wavelength division multiplexer; The first laser is used to convert the second synchronization signal into a first optical signal; The second laser is used to convert the second reference signal into a second optical signal; The first wavelength division multiplexer is used to combine the first optical signal and the second optical signal into the third optical signal; The second wavelength division multiplexer is used to divide the fourth optical signal into a fifth optical signal and a sixth optical signal; The first detector is used to convert the fifth optical signal into the third reference signal; The second detector is used to convert the sixth optical signal into the third synchronization signal.

5. The radar time-frequency synchronization device according to claim 4, characterized in that, The optical transmission unit includes an optical fiber and a tunable optical delay line; The optical fiber is used to transmit the third optical signal; The adjustable optical delay line is used to adjust the phase of the third optical signal according to the phase difference signal to obtain the fourth optical signal.

6. The radar time-frequency synchronization device according to claim 5, characterized in that, The first signal amplifier receives the first synchronization signal at its input terminal and outputs the second synchronization signal at its output terminal. The input terminal of the second signal amplifier receives the first reference signal, and the output terminal of the second signal amplifier outputs the second reference signal; The input terminal of the third signal amplifier receives the third synchronization signal, and the output terminal of the third signal amplifier outputs the fourth synchronization signal. The first input terminal of the phase detector receives the first reference signal, the second input terminal of the phase detector receives the third reference signal, and the output terminal of the phase detector outputs the phase difference signal.

7. The radar time-frequency synchronization device according to claim 6, characterized in that, The input terminal of the first laser receives the second synchronization signal, and the output terminal of the first laser outputs the first optical signal; The input terminal of the second laser receives the second reference signal, and the output terminal of the second laser outputs the second optical signal; The first input terminal of the first wavelength division multiplexer receives the first optical signal, the second input terminal of the first wavelength division multiplexer receives the second optical signal, and the output terminal of the first wavelength division multiplexer outputs the third optical signal. The input terminal of the second wavelength division multiplexer receives the fourth optical signal, the first output terminal of the second wavelength division multiplexer outputs the fifth optical signal, and the second output terminal of the second wavelength division multiplexer outputs the sixth optical signal. The input terminal of the first detector receives the fifth optical signal, and the output terminal of the first detector outputs the third reference signal; The input terminal of the second detector receives the sixth optical signal, and the output terminal of the second detector receives the third synchronization signal.

8. The radar time-frequency synchronization device according to claim 7, characterized in that, The input end of the optical fiber receives the third optical signal, and the output end of the optical fiber outputs the third optical signal; The first input terminal of the adjustable optical delay line receives the phase difference signal, the second input terminal of the adjustable optical delay line receives the third optical signal, and the output terminal of the adjustable optical delay line outputs the fourth optical signal.

9. The radar time-frequency synchronization device according to claim 8, characterized in that, The length of the optical fiber is less than or equal to 10 km.

10. A radar time-frequency synchronization method, characterized in that, include: The first synchronization signal and the first reference signal are amplified by an electrical signal unit to obtain the second synchronization signal and the second reference signal, and the third synchronization signal is amplified to obtain the fourth synchronization signal. The third reference signal and the first reference signal are phase-discriminated to obtain the phase difference signal. The optical transceiver unit converts and combines the second synchronization signal and the second reference signal to obtain the third optical signal, and separates and converts the fourth optical signal to obtain the third reference signal and the third synchronization signal. The third optical signal is transmitted using an optical transmission unit, and the fourth optical signal is obtained by adjusting the third optical signal according to the phase difference signal.

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