Full-band noise microwave source system and microwave signal generation method

Abstract

The invention relates to the technical field of microwave photonics, and discloses a full-band noise microwave source system and a microwave signal generation method. An optical reference unit is used for generating an optical reference signal; the photoelectric phase detection unit is connected with the optical reference unit and is used for receiving the optical reference signal and a feedback signal sent by the microwave oscillation unit and outputting a beat frequency electric signal for reflecting a phase error; the servo control unit is connected with the photoelectric phase detection unit and the microwave oscillation unit and is used for separating the beat frequency electric signal into a low-frequency control signal and a high-frequency control signal; the microwave oscillation unit is connected with the servo control unit and outputs a target microwave signal in response to the low-frequency control signal and the high-frequency control signal. A beat frequency electric signal is separated into a low-frequency path and a high-frequency path by using the servo control unit, so that targeted suppression of phase noise of different frequency bands in a single signal source is realized.

Description

Technical Field

[0001] This invention relates to the field of microwave photonics technology, specifically to a full-band noise microwave source system and a microwave signal generation method. Background Technology

[0002] In fields such as radar detection, deep space communication, and high-end electronic testing, increasingly stringent requirements are being placed on the phase noise performance of microwave signal sources, especially in the 10GHz to 20GHz frequency band, where extremely low phase noise is required simultaneously at both the near end (e.g., 100Hz to 10kHz offset) and the far end (e.g., offsets above 10MHz). One type of traditional microwave frequency synthesis technique is an electrical phase-locked source based on a yttrium iron garnet (YIG) oscillator. While this method, which controls the YIG oscillator through a crystal reference source and a phase-locked loop (PLL), demonstrates excellent performance in far-end phase noise, the noise degradation effect during frequency doubling makes it difficult to overcome physical limits in near-end phase noise, thus failing to meet the requirements of applications such as ultra-high precision Doppler measurements. Another type is a microwave source based on electro-optical frequency division (eOFD) technology. It generates microwave signals using the principle of optical frequency division and has excellent near-end phase noise. However, it usually uses a monolithic microwave integrated circuit (MMIC) voltage-controlled oscillator (VCO). Due to the low quality factor of the MMIC VCO and the limitation of shot noise of the photodetector, the far-end phase noise is poor.

[0003] Therefore, it is currently impossible to achieve ultra-low phase noise across the entire frequency band simultaneously in the same signal source, which has become a problem restricting further performance improvements in radar, communication, and precision measurement systems. Summary of the Invention

[0004] In view of this, the present invention provides a full-band noise microwave source system and a microwave signal generation method to solve the problem that it is impossible to achieve ultra-low phase noise across the entire frequency band simultaneously in the same signal source.

[0005] In a first aspect, the present invention provides a full-band noise microwave source system, the system comprising: An optical reference unit is used to generate an optical reference signal; The photoelectric phase detection unit is connected to the optical reference unit and is used to receive the optical reference signal and the feedback signal emitted by the microwave oscillation unit, and output a beat frequency electrical signal to reflect the phase error. A servo control unit, connected to the photoelectric phase detection unit and the microwave oscillation unit, is used to separate the beat frequency electrical signal into a low-frequency control signal and a high-frequency control signal; A microwave oscillation unit is connected to the servo control unit. The microwave oscillation unit includes a main tuning coil and a frequency modulation coil. The microwave oscillation unit responds to the low-frequency control signal and the high-frequency control signal to output a target microwave signal. The low-frequency control signal is used to drive the main tuning coil, and the high-frequency control signal is used to drive the frequency modulation coil.

[0006] In some alternative implementations, the optical reference unit includes at least a semiconductor laser and an optical resonant cavity, wherein the semiconductor laser is optically coupled to the optical resonant cavity to form a self-injection locked structure.

[0007] In some optional embodiments, the photoelectric phase detection unit includes at least an electro-optic modulator, a photodetector, and a mixer, wherein the electro-optic modulator is used to modulate the optical reference signal based on the feedback signal emitted by the microwave oscillation unit to generate an optical frequency comb signal. The photodetector generates a first electrical signal based on the optical frequency comb signal; The mixer receives an external reference signal and the first electrical signal, compares the external reference signal with the first electrical signal, and outputs a beat frequency electrical signal to reflect the phase error.

[0008] In some optional embodiments, the optical phase detection unit further includes an optical filter for selecting target comb teeth from the optical frequency comb signal; The photodetector generates a first electrical signal based on the optical frequency comb signal, including: converting the optical signal of the target comb tooth into a first electrical signal.

[0009] In some alternative implementations, the servo control unit includes a frequency division network for separating the beat frequency electrical signal into a low-frequency control signal and a high-frequency control signal.

[0010] In some optional embodiments, the servo control unit further includes a gain scheduling module, which is used to adjust the gain value of the high-frequency control signal according to the frequency of the target microwave signal output by the microwave oscillation unit.

[0011] In some alternative embodiments, the microwave oscillation unit is a yttrium iron garnet oscillator, the main tuning coil is used to set the center oscillation frequency of the yttrium iron garnet oscillator, and the frequency modulation coil is used to adjust the output phase of the yttrium iron garnet oscillator.

[0012] In a second aspect, the present invention provides a microwave signal generation method for use in any of the above-described full-band noise microwave source systems, the method comprising: The optical reference unit generates an optical reference signal; The photoelectric phase detection unit outputs a beat frequency electrical signal to reflect the phase error based on the optical reference signal and the feedback signal emitted by the microwave oscillation unit. The servo control unit separates the beat frequency electrical signal into a low-frequency control signal and a high-frequency control signal. The low-frequency control signal is used to drive the main tuning coil, and the high-frequency control signal is used to drive the frequency modulation coil. The microwave oscillation unit responds to the low-frequency control signal and the high-frequency control signal and outputs the target microwave signal.

[0013] The full-band noise microwave source system provided in this embodiment of the invention includes an optical reference unit, a photoelectric phase detection unit, a servo control unit, and a microwave oscillation unit. The optical reference unit generates an optical reference signal. The photoelectric phase detection unit, connected to the optical reference unit, receives the optical reference signal and a feedback signal from the microwave oscillation unit, and outputs a beat frequency electrical signal reflecting phase error. The servo control unit, connected to the photoelectric phase detection unit and the microwave oscillation unit, separates the beat frequency electrical signal into a low-frequency control signal and a high-frequency control signal. The microwave oscillation unit, connected to the servo control unit, includes a main tuning coil and a frequency modulation coil. Responding to the low-frequency and high-frequency control signals, the microwave oscillation unit outputs a target microwave signal, wherein the low-frequency control signal drives the main tuning coil, and the high-frequency control signal drives the frequency modulation coil. The full-band noise microwave source system provided in this invention forms a closed loop by integrating an optical reference unit, a photoelectric phase detection unit, a servo control unit, and a microwave oscillation unit. The servo control unit separates the beat frequency electrical signal output from the photoelectric phase detection unit into low-frequency and high-frequency control signals, which drive the main tuning coil and frequency modulation coil of the microwave oscillation unit respectively. This achieves targeted suppression of phase noise in different frequency bands within a single signal source. Specifically, the low-frequency control signal slowly stabilizes the oscillator's center frequency through the main tuning coil, effectively compensating for slow-varying system drift; the high-frequency control signal rapidly fine-tunes the output phase through the frequency modulation coil, directly suppressing near-carrier frequency phase fluctuations. Through this frequency-division collaborative control architecture, the high stability of the optical reference is effectively transferred to the microwave domain and applied to the oscillator, while fully leveraging the oscillator's low-noise advantage at the far end. This simultaneously improves the near-end and far-end phase noise performance within a complete feedback loop, achieving overall optimization of noise characteristics across the entire frequency band. Attached Figure Description

[0014] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of a full-band noise microwave source system according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a full-band noise microwave source system according to an embodiment of the present invention; Figure 3 This is a schematic flowchart of a microwave signal generation method according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] In fields such as radar detection, deep space communication, and high-end electronic testing, increasingly stringent requirements are being placed on the phase noise performance of microwave signal sources, especially in the 10GHz to 20GHz frequency band, where extremely low phase noise is required simultaneously at both the near end (e.g., 100Hz to 10kHz offset) and the far end (e.g., offsets above 10MHz). Based on this requirement, this invention provides a full-band noise microwave source system and a microwave signal generation method.

[0018] This embodiment provides a full-band noise microwave source system. Figure 1This is a schematic diagram of a full-band noise microwave source system according to an embodiment of the present invention. The system includes: an optical reference unit, a photoelectric phase detection unit, a servo control unit, and a microwave oscillation unit. The optical reference unit generates an optical reference signal. The photoelectric phase detection unit is connected to the optical reference unit and receives the optical reference signal and a feedback signal from the microwave oscillation unit, outputting a beat frequency electrical signal reflecting phase error. The servo control unit is connected to the photoelectric phase detection unit and the microwave oscillation unit, separating the beat frequency electrical signal into a low-frequency control signal and a high-frequency control signal. The microwave oscillation unit is connected to the servo control unit and includes a main tuning coil and a frequency modulation coil. The microwave oscillation unit responds to the low-frequency control signal and the high-frequency control signal, outputting a target microwave signal. The low-frequency control signal drives the main tuning coil, and the high-frequency control signal drives the frequency modulation coil.

[0019] The optical reference unit is the system's ultra-stable frequency reference source, used to generate an optical reference signal with extremely high spectral purity. In some optional embodiments, the optical reference unit includes at least a semiconductor laser and an optical resonant cavity, with the semiconductor laser optically coupled to the optical resonant cavity to form a self-injection locked structure.

[0020] Furthermore, the semiconductor laser is a distributed feedback semiconductor laser, such as... Figure 2 As shown, two distributed feedback semiconductor lasers can be used, namely... Figure 2 In this embodiment, either the 221-laser LD1 or the 222-laser LD2 together provide the initial laser output. The light output from the semiconductor laser is guided by the 231-optical coupler 1, the 232-optical coupler 2, and the 240-combiner 1 to enter the 260-resonator. In this embodiment, the optical resonator is a 260-resonator. The optical resonator can be a resonator wound with ordinary optical fiber or a helical waveguide resonator based on silicon nitride (Si3N4). The silicon nitride-based helical waveguide resonator is a high-Q integrated optical microcavity. The semiconductor laser and the helical waveguide resonator are coupled through components such as the 231-optical coupler 1, the 232-optical coupler 2, and the 240-combiner 1 to form a self-injection-locked structure, thereby narrowing the laser linewidth to the extreme and generating an optical reference signal O. ref The frequency-stabilized optical reference signal is output to the photoelectric phase detection unit through the 330-combiner 2. The optical reference signal is a dual-frequency optical reference signal.

[0021] In some optional implementations, the photoelectric phase detection unit includes at least an electro-optic modulator, a photodetector, and a mixer. The electro-optic modulator is used to modulate the optical reference signal based on the feedback signal emitted by the microwave oscillation unit to generate an optical frequency comb signal. The photodetector generates a first electrical signal based on the optical frequency comb signal. The mixer receives the external reference signal and the first electrical signal, compares the external reference signal with the first electrical signal, and outputs a beat frequency electrical signal to reflect the phase error.

[0022] Furthermore, the optical phase detection unit also includes an optical filter for selecting target comb teeth from the optical frequency comb signal; the photodetector generates a first electrical signal based on the optical frequency comb signal, including converting the optical signal of the target comb tooth into the first electrical signal.

[0023] Specifically, the optical reference signal is amplified by an optical amplifier (601) and then enters an electro-optic modulator. The electro-optic modulator can be a thin-film lithium niobate (TFLN) 610 optical comb, used to receive feedback signals from the microwave oscillation unit. After entering the electro-optic modulator, the optical reference signal generates a broadband optical frequency comb. The electro-optic modulator uses the feedback signal from the microwave oscillation unit to modulate the optical reference signal, generating an optical frequency comb signal. The optical frequency comb signal passes through an optical filter (620), which selects the target comb teeth to beat with the optical reference signal. A photodetector (630) converts the optical signal of the target comb teeth into a first electrical signal through optical beat frequency conversion. The first electrical signal is input to a mixer (640). The mixer receives an external reference signal, compares it with the first electrical signal, and generates an error signal, which is the beat frequency electrical signal used to reflect the phase error.

[0024] The external reference signal is a standard reference signal generated by an external high-stability crystal oscillator or atomic clock. It is input to the mixer as the local oscillator, and the mixer outputs the sum and difference frequency components of the two signals. The difference frequency component mainly manifests as DC or low-frequency voltage fluctuations, the amplitude of which is proportional to the instantaneous phase difference between the two signals. This difference frequency is the output beat frequency electrical signal, reflecting the degree of deviation of the microwave phase generated by the microwave oscillation unit relative to the standard reference source.

[0025] The beat frequency electrical signal output by the photoelectric phase detection unit enters the servo control unit.

[0026] In some alternative implementations, the servo control unit includes a frequency division network for separating the beat frequency electrical signal into a low-frequency control signal and a high-frequency control signal. The servo control unit also includes a gain scheduling module for adjusting the gain value of the high-frequency control signal according to the frequency of the target microwave signal output by the microwave oscillation unit.

[0027] The servo control unit includes a frequency division network that receives the electrical signal output from the photoelectric phase detection unit and separates the beat frequency signal into a low-frequency control signal and a high-frequency control signal according to a preset cutoff frequency (e.g., 1kHz). The gain scheduling module monitors the frequency of the target microwave signal output by the microwave oscillation unit in real time. As the sensitivity of the frequency modulation coil of the microwave oscillation unit changes with the frequency, the gain scheduling module dynamically adjusts the gain value of the high-frequency control signal input to the frequency modulation coil to maintain loop stability across the entire frequency band. Figure 2 The 650-servo filter in the system can achieve this functionality by integrating this algorithm or circuit.

[0028] In some alternative implementations, the microwave oscillation unit is a yttrium iron garnet oscillator, the main tuning coil is used to set the center oscillation frequency of the yttrium iron garnet oscillator, and the frequency modulation coil is used to adjust the output phase of the yttrium iron garnet oscillator.

[0029] The yttrium iron garnet (YIG) oscillator integrates a main tuning coil and a frequency modulation coil. The main tuning coil receives low-frequency control signals from the servo control unit and sets the center oscillation frequency of the YIG oscillator. Its slow response is used for wide-range tuning and slow drift compensation. The frequency modulation coil receives high-frequency control signals from the servo control unit and rapidly adjusts the output phase of the YIG oscillator to suppress near-end phase noise. Driven by the dual coils, the 660-YIG oscillator outputs the final target microwave signal. One path of this target microwave signal serves as the system output, while the other path serves as a feedback signal to the 610-optical comb of the photoelectric phase detection unit, forming a closed loop.

[0030] The full-band noise microwave source system provided in this embodiment of the invention includes an optical reference unit, a photoelectric phase detection unit, a servo control unit, and a microwave oscillation unit. The optical reference unit generates an optical reference signal. The photoelectric phase detection unit, connected to the optical reference unit, receives the optical reference signal and a feedback signal from the microwave oscillation unit, and outputs a beat frequency electrical signal reflecting phase error. The servo control unit, connected to the photoelectric phase detection unit and the microwave oscillation unit, separates the beat frequency electrical signal into a low-frequency control signal and a high-frequency control signal. The microwave oscillation unit, connected to the servo control unit, includes a main tuning coil and a frequency modulation coil. Responding to the low-frequency and high-frequency control signals, the microwave oscillation unit outputs a target microwave signal, wherein the low-frequency control signal drives the main tuning coil, and the high-frequency control signal drives the frequency modulation coil.

[0031] The full-band noise microwave source system provided in this invention forms a closed loop by integrating an optical reference unit, a photoelectric phase detection unit, a servo control unit, and a microwave oscillation unit. The servo control unit separates the beat frequency electrical signal output from the photoelectric phase detection unit into low-frequency and high-frequency control signals, which drive the main tuning coil and frequency modulation coil of the microwave oscillation unit respectively. This achieves targeted suppression of phase noise in different frequency bands within a single signal source. Specifically, the low-frequency control signal slowly stabilizes the oscillator's center frequency through the main tuning coil, effectively compensating for slow-varying system drift; the high-frequency control signal rapidly fine-tunes the output phase through the frequency modulation coil, directly suppressing near-carrier frequency phase fluctuations. Through this frequency-division collaborative control architecture, the high stability of the optical reference is effectively transferred to the microwave domain and applied to the oscillator, while fully leveraging the oscillator's low-noise advantage at the far end. This simultaneously improves the near-end and far-end phase noise performance within a complete feedback loop, achieving overall optimization of noise characteristics across the entire frequency band.

[0032] According to an embodiment of the present invention, a microwave signal generation method embodiment is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0033] This embodiment provides a microwave signal generation method, which can be used in the aforementioned full-band noise microwave source system. Figure 1 This is a flowchart of a microwave signal generation method according to an embodiment of the present invention, such as... Figure 3 As shown, the process includes the following steps: Step S301: The optical reference unit generates an optical reference signal.

[0034] The optical reference unit is the system's ultra-stable frequency reference source, used to generate an optical reference signal with extremely high spectral purity. Specifically, an initial laser beam is generated using a semiconductor laser, and the optical signal is coupled to an optical resonant cavity. Through optical feedback between the laser and the resonant cavity, a self-injection locking structure is formed, thereby generating the optical reference signal.

[0035] In some alternative implementations, the optical reference unit includes at least a semiconductor laser and an optical resonant cavity, and step S301 includes: forming a self-injection locking structure based on the coupling between the semiconductor laser and the integrated optical resonant cavity to generate an optical reference signal.

[0036] The semiconductor laser is a distributed feedback semiconductor laser, such as... Figure 2 As shown, two distributed feedback semiconductor lasers can be used, namely... Figure 2In this embodiment, lasers LD1 (221-laser) and LD2 (222-laser) provide the initial laser output, either together or by one of them. The light output from the semiconductor laser is guided by optical coupler 1 (231-optical coupler 1), optical coupler 2 (232-optical coupler 2), and combiner 1 (240-combiner 1) before entering the resonator (260-resonator). In this embodiment, the optical resonator is a 260-resonator. The resonator can be a resonator wound with ordinary optical fiber, or it can be an optical resonator based on silicon nitride (Si3N4) spiral waveguides. Silicon nitride-based spiral waveguide resonators are high-Q integrated optical microcavities. The semiconductor laser and the spiral waveguide resonator are coupled through components such as optical coupler 1 (231-optical coupler 1), optical coupler 2 (232-optical coupler 2), and combiner 1 (240-combiner 1) to form a self-injection-locked structure, thereby narrowing the laser linewidth to the extreme and generating an optical reference signal O. ref The frequency-stabilized optical reference signal is output to the photoelectric phase detection unit through the 330-combiner 2. The optical reference signal is a dual-frequency optical reference signal.

[0037] In step S302, the photoelectric phase detection unit outputs a beat frequency electrical signal to reflect the phase error based on the optical reference signal and the feedback signal emitted by the microwave oscillation unit.

[0038] In some optional implementations, the photoelectric phase detection unit includes at least an electro-optic modulator, a photodetector, and a mixer, wherein the electro-optic modulator is used to modulate the optical reference signal based on a feedback signal emitted by the microwave oscillation unit to generate an optical frequency comb signal; the photodetector generates a first electrical signal based on the optical frequency comb signal; the mixer receives an external reference signal and the first electrical signal, compares the external reference signal with the first electrical signal, and outputs a beat frequency electrical signal to reflect the phase error.

[0039] Furthermore, the optical phase detection unit also includes an optical filter for selecting target comb teeth from the optical frequency comb signal; the photodetector generates a first electrical signal based on the optical frequency comb signal, including converting the optical signal of the target comb tooth into the first electrical signal.

[0040] Specifically, the optical reference signal is amplified by an optical amplifier (601) and then enters an electro-optic modulator. The electro-optic modulator can be a thin-film lithium niobate (TFLN) 610 optical comb, used to receive feedback signals from the microwave oscillation unit. After entering the electro-optic modulator, the optical reference signal generates a broadband optical frequency comb. The electro-optic modulator uses the feedback signal from the microwave oscillation unit to modulate the optical reference signal, generating an optical frequency comb signal. The optical frequency comb signal passes through an optical filter (620), which selects the target comb teeth to beat with the optical reference signal. A photodetector (630) converts the optical signal of the target comb teeth into a first electrical signal through optical beat frequency conversion. The first electrical signal is input to a mixer (640). The mixer receives an external reference signal, compares it with the first electrical signal, and generates an error signal, which is the beat frequency electrical signal used to reflect the phase error.

[0041] The external reference signal is a standard reference signal generated by an external high-stability crystal oscillator or atomic clock. It is input to the mixer as the local oscillator, and the mixer outputs the sum and difference frequency components of the two signals. The difference frequency component mainly manifests as DC or low-frequency voltage fluctuations, the amplitude of which is proportional to the instantaneous phase difference between the two signals. This difference frequency is the output beat frequency electrical signal, reflecting the degree of deviation of the microwave phase generated by the microwave oscillation unit relative to the standard reference source.

[0042] The beat frequency electrical signal output by the photoelectric phase detection unit enters the servo control unit.

[0043] In step S303, the servo control unit separates the beat frequency electrical signal into a low-frequency control signal and a high-frequency control signal. The low-frequency control signal is used to drive the main tuning coil, and the high-frequency control signal is used to drive the frequency modulation coil.

[0044] The servo control unit can be a servo filter. Through its internal frequency divider network, the electrical signal is separated into two independent control signals at a preset cutoff frequency (e.g., 1kHz). One signal is a low-frequency control signal, which contains the slowly changing components of the error signal, corresponding to the system's frequency drift and center frequency setting error. The other signal is a high-frequency control signal, which contains the rapidly changing components of the error signal, corresponding to the broadband phase noise that needs to be suppressed.

[0045] Specifically, the servo control unit includes a frequency division network that receives the beat frequency electrical signal output by the photoelectric phase detection unit and separates it into a low-frequency control signal and a high-frequency control signal according to a preset cutoff frequency (e.g., 1kHz). The gain scheduling module monitors the frequency of the target microwave signal output by the microwave oscillation unit in real time. As the sensitivity of the frequency modulation coil of the microwave oscillation unit changes with the frequency, the gain scheduling module dynamically adjusts the gain value of the high-frequency control signal input to the frequency modulation coil to maintain the stability of the loop across the entire frequency band.

[0046] In step S304, the microwave oscillation unit responds to the low-frequency control signal and the high-frequency control signal and outputs the target microwave signal.

[0047] The microwave oscillation unit is a yttrium iron garnet oscillator. The main tuning coil is used to set the center oscillation frequency of the yttrium iron garnet oscillator, and the frequency modulation coil is used to adjust the output phase of the yttrium iron garnet oscillator.

[0048] The yttrium iron garnet (YIG) oscillator integrates a main tuning coil and a frequency modulation coil. The main tuning coil receives low-frequency control signals from the servo control unit and sets the center oscillation frequency of the YIG oscillator. Its slow response is used for wide-range tuning and slow drift compensation. The frequency modulation coil receives high-frequency control signals from the servo control unit and rapidly adjusts the output phase of the YIG oscillator to suppress near-end phase noise. Driven by the dual coils, the 660-YIG oscillator outputs the final target microwave signal. One path of this target microwave signal serves as the system output, while the other path serves as a feedback signal to the 610-optical comb of the photoelectric phase detection unit, forming a closed loop.

[0049] The microwave signal generation method provided in this embodiment includes: an optical reference unit generating an optical reference signal; an optoelectronic phase detection unit outputting an electrical signal reflecting phase error based on the optical reference signal and a feedback signal emitted by a microwave oscillation unit; a servo control unit separating the beat frequency electrical signal into a low-frequency control signal and a high-frequency control signal, wherein the low-frequency control signal is used to drive the main tuning coil and the high-frequency control signal is used to drive the frequency modulation coil; and the microwave oscillation unit responding to the low-frequency control signal and the high-frequency control signal outputting a target microwave signal.

[0050] Please see Figure 4 , Figure 4 This is a schematic diagram of the structure of a computer device provided in an optional embodiment of the present invention, such as... Figure 4 As shown, the computer device includes one or more processors 10, memory 20, and interfaces for connecting the components, including high-speed interfaces and low-speed interfaces. The components communicate with each other via different buses and can be mounted on a common motherboard or otherwise installed as needed. The processors can process instructions executed within the computer device, including instructions stored in or on memory to display graphical information of a GUI on external input / output devices (such as display devices coupled to the interfaces). In some alternative implementations, multiple processors and / or multiple buses can be used with multiple memories and multiple memory modules, if desired. Similarly, multiple computer devices can be connected, each providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system). Figure 4 Take a processor 10 as an example.

[0051] Processor 10 may be a central processing unit, a network processor, or a combination thereof. Processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GDA), or any combination thereof.

[0052] The memory 20 stores instructions executable by at least one processor 10 to cause the at least one processor 10 to perform the method shown in the above embodiments.

[0053] The memory 20 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the computer device. Furthermore, the memory 20 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some alternative embodiments, the memory 20 may optionally include memory remotely located relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0054] The memory 20 may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as flash memory, hard disk or solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0055] The computer device also includes a communication interface 30 for communicating with other devices or communication networks.

[0056] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the methods shown in the above embodiments.

[0057] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0058] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and all such modifications and variations fall within the scope defined by the invention.

Claims

1. A full-band noise microwave source system, characterized in that, The system includes: An optical reference unit is used to generate an optical reference signal; The photoelectric phase detection unit is connected to the optical reference unit and is used to receive the optical reference signal and the feedback signal emitted by the microwave oscillation unit, and output a beat frequency electrical signal to reflect the phase error. A servo control unit, connected to the photoelectric phase detection unit and the microwave oscillation unit, is used to separate the beat frequency electrical signal into a low-frequency control signal and a high-frequency control signal; A microwave oscillation unit is connected to the servo control unit. The microwave oscillation unit includes a main tuning coil and a frequency modulation coil. The microwave oscillation unit responds to the low-frequency control signal and the high-frequency control signal to output a target microwave signal. The low-frequency control signal is used to drive the main tuning coil, and the high-frequency control signal is used to drive the frequency modulation coil.

2. The full-band noise microwave source system according to claim 1, characterized in that, The optical reference unit includes at least a semiconductor laser and an optical resonant cavity, wherein the semiconductor laser is optically coupled to the optical resonant cavity to form a self-injection locking structure.

3. The full-band noise microwave source system according to claim 1, characterized in that, The photoelectric phase detection unit includes at least an electro-optic modulator, a photodetector, and a mixer, wherein the electro-optic modulator is used to modulate the optical reference signal based on the feedback signal emitted by the microwave oscillation unit to generate an optical frequency comb signal. The photodetector generates a first electrical signal based on the optical frequency comb signal; The mixer receives an external reference signal and the first electrical signal, compares the external reference signal with the first electrical signal, and outputs a beat frequency electrical signal to reflect the phase error.

4. The full-band noise microwave source system according to claim 3, characterized in that, The optical phase detection unit further includes an optical filter, which is used to select target comb teeth from the optical frequency comb signal; The photodetector generates a first electrical signal based on the optical frequency comb signal, including: converting the optical signal of the target comb tooth into a first electrical signal.

5. The full-band noise microwave source system according to claim 1, characterized in that, The servo control unit includes a frequency division network, which is used to separate the beat frequency electrical signal into a low-frequency control signal and a high-frequency control signal.

6. The full-band noise microwave source system according to claim 5, characterized in that, The servo control unit further includes a gain scheduling module, which is used to adjust the gain value of the high-frequency control signal according to the frequency of the target microwave signal output by the microwave oscillation unit.

7. The full-band noise microwave source system according to claim 1, characterized in that, The microwave oscillation unit is a yttrium iron garnet oscillator. The main tuning coil is used to set the center oscillation frequency of the yttrium iron garnet oscillator, and the frequency modulation coil is used to adjust the output phase of the yttrium iron garnet oscillator.

8. A method for generating microwave signals, characterized in that, For the full-band noise microwave source system according to any one of claims 1 to 7, the method comprises: The optical reference unit generates an optical reference signal; The photoelectric phase detection unit outputs a beat frequency electrical signal to reflect the phase error based on the optical reference signal and the feedback signal emitted by the microwave oscillation unit. The servo control unit separates the beat frequency electrical signal into a low-frequency control signal and a high-frequency control signal. The low-frequency control signal is used to drive the main tuning coil, and the high-frequency control signal is used to drive the frequency modulation coil. The microwave oscillation unit responds to the low-frequency control signal and the high-frequency control signal and outputs the target microwave signal.

9. The method according to claim 8, characterized in that, The optical reference unit includes at least a semiconductor laser and an integrated optical resonant cavity, and generates an optical reference signal, including: Based on the coupling between the semiconductor laser and the integrated optical resonator, a self-injection locking structure is formed to generate an optical reference signal.

10. The method according to claim 8, characterized in that, The photoelectric phase detection unit includes at least an electro-optic modulator, a photodetector, and a mixer, wherein the electro-optic modulator is used to modulate the optical reference signal based on the feedback signal emitted by the microwave oscillation unit to generate an optical frequency comb signal. The photodetector generates a first electrical signal based on the optical frequency comb signal; The mixer receives an external reference signal and the first electrical signal, compares the external reference signal with the first electrical signal, and outputs a beat frequency electrical signal to reflect the phase error.

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