A spaceborne variable reference multi-loop phase-locked local oscillator

Abstract

The present application provides a satellite-borne variable reference multi-loop phase-locked local oscillator source, which outputs a variable crystal oscillator to generate a local oscillator reference frequency and sends the local oscillator reference frequency to a first phase-locked loop and a second phase-locked loop; the first phase-locked loop performs mixing processing based on the target feedback frequency output by a mixing unit and the local oscillator reference frequency to generate a local oscillator frequency and a first feedback frequency corresponding to the satellite-borne variable reference multi-loop phase-locked local oscillator source, and sends the first feedback frequency to the mixing unit; the second phase-locked loop performs mixing based on the local oscillator reference frequency and its own feedback mechanism to obtain a second feedback frequency and send it to the mixing unit; the mixing unit performs down-conversion processing on the first feedback frequency and the second feedback frequency to generate a target feedback frequency and send it to the first phase-locked loop. The local oscillator source formed by combining multi-loop phase-locked technology with an output variable crystal oscillator can, on the one hand, achieve the local oscillator frequency output required by satellite-borne equipment, and on the other hand, simplify the circuit structure and reduce costs.

Description

Technical Field

[0001] The present application relates to the technical field of microwave local oscillator source output, and in particular to a satellite-borne variable reference multi-loop phase-locked local oscillator source. Background Art

[0002] Because satellite-borne equipment is limited by component performance and usage range, one of the previous technologies for local oscillator design is to use a single-loop digital phase-locked loop solution to achieve local oscillator frequency output. However, this design method generally requires a very complex phase-locked loop control circuit to complete integer and fractional frequency division, thereby further achieving any frequency output below 20GHz, and the circuit is complex. Another design solution is to use an SOI (Silicon-On-Insulator) phase-locked chip to integrate the local oscillator. However, this local oscillator can only achieve integer frequency division, not fractional frequency division, and the output frequency is not high. In addition, the operating frequency of satellite-borne equipment is mostly fractional frequency. Therefore, this design solution cannot meet the local oscillator frequency requirements of satellite-borne equipment. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide at least a satellite-borne variable reference multi-loop phase-locked local oscillator source. The local oscillator source formed by combining multi-loop phase-locked technology with an output variable crystal oscillator can, on the one hand, realize the local oscillator frequency output required by the satellite-borne equipment, and on the other hand, simplify the circuit structure and reduce costs.

[0004] This application mainly includes the following aspects:

[0005] In a first aspect, an embodiment of the present application provides a satellite-borne variable reference multi-loop phase-locked local oscillator source, which includes an output variable crystal oscillator, a first phase-locked loop, a second phase-locked loop, and a mixing unit, wherein the output variable crystal oscillator generates a local oscillator reference frequency and sends the local oscillator reference frequency to the first phase-locked loop and the second phase-locked loop; the first phase-locked loop performs mixing processing based on the target feedback frequency and the local oscillator reference frequency output by the mixing unit to generate a local oscillator frequency and a first feedback frequency corresponding to the satellite-borne variable reference multi-loop phase-locked local oscillator source, and sends the first feedback frequency to the mixing unit; the second phase-locked loop performs mixing based on the local oscillator reference frequency and its own feedback mechanism to obtain a second feedback frequency and send it to the mixing unit; the mixing unit performs down-conversion processing on the first feedback frequency and the second feedback frequency to generate a target feedback frequency and send it to the first phase-locked loop.

[0006] In one possible embodiment, the first phase-locked loop includes a first phase detector, a first loop filter, and a first voltage-controlled oscillator, wherein the first phase detector receives a target feedback frequency from a frequency mixing unit; the first phase detector generates a corresponding first error signal based on a difference between a local oscillator reference frequency and the target feedback frequency, and sends the signal to the first loop filter; the first loop filter filters and smoothes the first error signal to generate a first control voltage, and sends the first control voltage to the first voltage-controlled oscillator; the first voltage-controlled oscillator adjusts its corresponding output frequency according to the first control voltage to obtain a local oscillator frequency.

[0007] In a possible embodiment, the satellite-borne variable reference multi-loop phase-locked local oscillator source also includes a frequency divider, wherein the first phase-locked loop sends the local oscillator frequency to the frequency divider for frequency division processing, generates a first feedback frequency and sends it to the mixing unit, and the first feedback frequency is half of the local oscillator frequency.

[0008] In one possible embodiment, the second phase-locked loop includes a second phase detector, a second loop filter, and a second voltage-controlled oscillator. The second phase detector generates a corresponding second error signal based on a difference between a local oscillator reference frequency and a second feedback frequency, and sends the signal to the second loop filter. The second loop filter filters and smoothes the second error signal to generate a second control voltage, and sends the second control voltage to the second voltage-controlled oscillator. The second voltage-controlled oscillator adjusts its corresponding output frequency based on the second control voltage to obtain an adjusted second feedback frequency.

[0009] In one possible implementation, the output variable crystal oscillator is a customized crystal oscillator that controls the local oscillator reference frequency output by a voltage value, or a digital-to-analog converter, where the local oscillator reference frequency output by the digital-to-analog converter is determined by a control signal output by a microcontroller.

[0010] In one possible implementation, the following configuration relationship exists between the target feedback frequency and the local oscillator reference frequency:

[0011]

[0012] in, Indicates the target feedback frequency of the mixer output, Indicates the local oscillator reference frequency, represents the first set value corresponding to the first phase detector in the first phase-locked loop, is an integer.

[0013] In one possible implementation, the second feedback frequency output by the second phase-locked loop and the local oscillator reference frequency have the following configuration relationship:

[0014]

[0015] in, represents the second feedback frequency output by the second phase-locked loop, Indicates the local oscillator reference frequency, represents the second set value corresponding to the second phase detector in the second phase-locked loop, is an integer.

[0016] In one possible implementation, the following configuration relationship exists between the local oscillator reference frequency and the local oscillator frequency output by the onboard variable reference multi-loop phase-locked local oscillator source:

[0017]

[0018] in, Indicates the local oscillator reference frequency, Indicates the local oscillator frequency corresponding to the satellite-borne variable reference multi-loop phase-locked local oscillator source, Indicates the frequency division number corresponding to the frequency divider in the first phase-locked loop, is an integer, indicating the second setting number corresponding to the second phase-locked loop, is an integer representing the first setting number corresponding to the first phase-locked loop.

[0019] In a possible implementation, the phase-locked loop is a phase-locked loop integrated chip manufactured by silicon on insulator.

[0020] In one possible implementation, the satellite-borne variable reference multi-loop phase-locked local oscillator source further includes a power supply and an output filter, wherein the power supply provides operating power for the satellite-borne variable reference multi-loop phase-locked local oscillator source; and the output filter filters the local oscillator frequency output by the first phase-locked loop to obtain a processed local oscillator frequency.

[0021] The embodiment of the present application provides a satellite-borne variable reference multi-loop phase-locked local oscillator source, which outputs a variable crystal oscillator to generate a local oscillator reference frequency and sends the local oscillator reference frequency to a first phase-locked loop and a second phase-locked loop; the first phase-locked loop performs mixing processing based on the target feedback frequency output by a mixing unit and the local oscillator reference frequency to generate a local oscillator frequency and a first feedback frequency corresponding to the satellite-borne variable reference multi-loop phase-locked local oscillator source, and sends the first feedback frequency to the mixing unit; the second phase-locked loop performs mixing based on the local oscillator reference frequency and its own feedback mechanism to obtain a second feedback frequency and send it to the mixing unit; the mixing unit performs down-conversion processing on the first feedback frequency and the second feedback frequency to generate a target feedback frequency and send it to the first phase-locked loop. The local oscillator source formed by combining multi-loop phase-locked technology with an output variable crystal oscillator can achieve the local oscillator frequency output required by satellite-borne equipment on the one hand, and simplify the circuit structure and reduce costs on the other hand.

[0022] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 One of the structural schematic diagrams of a satellite-borne variable reference multi-loop phase-locked local oscillator source provided by an embodiment of the present application is shown;

[0025] Figure 2 The second structural schematic diagram of a satellite-borne variable reference multi-loop phase-locked local oscillator source provided by an embodiment of the present application is shown. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of illustration and description and are not used to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowcharts can be implemented out of sequence, and steps without logical context can be reversed or implemented simultaneously. In addition, those skilled in the art, under the guidance of the contents of this application, can add one or more other operations to the flowchart, or remove one or more operations from the flowchart.

[0027] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application.

[0028] As the core component of radio frequency receivers and transmitters, local oscillators are mainly used in microwave remote sensing, communications, radar, electronic countermeasures and other fields. Their main function is to generate a stable signal with a specific frequency, which is used to mix with the input signal to achieve frequency up-conversion or down-conversion. The local oscillator on satellite-borne equipment places higher demands on the related technologies and high reliability of the local oscillator.

[0029] Because satellite-borne equipment is limited by component performance and usage range, previous local oscillator source designs have mostly adopted a single-loop digital phase-locked loop solution. This uses integer and fractional frequency division to enable the local oscillator source to output any frequency below 20 GHz. However, its disadvantage is that the control circuit is complex and most of them use CMOS circuit chips, resulting in low reliability for satellite-borne use. Currently, reliability is mostly improved through multiple redundant circuits, further exacerbating circuit complexity.

[0030] In another design scheme, the commonly used design technology for the local oscillator source is to use an SOI (silicon on insulator) phase-locked chip to achieve local oscillator frequency output. However, this design scheme can only achieve integer frequency division, cannot output fractional frequencies, and the output frequency is not high.

[0031] Based on this, the embodiments of the present application provide a satellite-borne variable reference multi-loop phase-locked local oscillator source. The local oscillator source formed by combining multi-loop phase-locked technology with an output variable crystal oscillator can achieve the local oscillator frequency output required by satellite-borne equipment while simplifying the circuit structure and reducing costs. The details are as follows:

[0032] See also Figure 1 , Figure 1 FIG1 shows one of the structural diagrams of a satellite-borne variable reference multi-loop phase-locked local oscillator provided by an embodiment of the present application. Figure 1 As shown, the satellite-borne variable reference multi-loop phase-locked local oscillator source provided in the embodiment of the present application includes an output variable crystal oscillator 1, a first phase-locked loop 21, a second phase-locked loop 22 and a mixing unit 3.

[0033] Preferably, the output variable crystal oscillator 1 generates the local oscillator reference frequency The first phase-locked loop 21 is based on the target feedback frequency output by the frequency mixing unit 3 and the second phase-locked loop 22. and the local oscillator reference frequency Perform frequency mixing to generate the local oscillator frequency corresponding to the onboard variable reference multi-loop phase-locked local oscillator source and the first feedback frequency , the first feedback frequency Sent to the mixing unit 3, the second phase-locked loop 22 is based on the local oscillator reference frequency And its own feedback mechanism to mix and get the second feedback frequency And sent to the mixing unit 3, the mixing unit 3 to the first feedback frequency and the second feedback frequency Perform down-conversion processing to generate the target feedback frequency And sent to the first phase-locked loop 21.

[0034] In a specific embodiment, according to the first setting number corresponding to the first phase-locked loop subsequently connected to the output variable crystal oscillator 1, the second setting number corresponding to the second phase-locked loop and the local oscillator frequency output by the satellite-borne variable reference multi-loop phase-locked local oscillator source , the local oscillator reference frequency output by the output variable crystal oscillator 1 can be determined, and according to the determined local oscillator reference frequency, and then according to the specific implementation scheme of the output variable crystal oscillator 1, its output is controlled to determine the local oscillator reference frequency.

[0035] In a preferred embodiment, the output variable crystal oscillator 1 can use a customized crystal oscillator, the customized crystal oscillator frequency covers 10MHz~150MHz, the customized crystal oscillator uses a constant temperature or temperature compensated type crystal oscillator, the tuning end of the customized crystal oscillator is connected to a given reference power supply VCC through a voltage divider module (such as a voltage divider resistor), and the output end of the customized crystal oscillator outputs the local oscillator reference frequency. By adjusting the resistance of the tuning end of the customized crystal oscillator of the voltage divider module, the voltage value Vt input to the tuning end of the customized crystal oscillator is adjusted. For the customized crystal oscillator, by adjusting the voltage value Vt input to its tuning end, the local oscillator reference frequency output by the customized crystal oscillator is changed or adjusted.

[0036] In another preferred embodiment, the output variable crystal oscillator 1 can also use a digital-to-analog converter DAC. The local oscillator reference frequency output by the digital-to-analog converter DAC is determined by a control signal output by a microcontroller. The microcontroller is an FPGA (programmable logic chip). The microcontroller outputs a control signal to the controlled end of the digital-to-analog converter DAC, so that the digital-to-analog converter DAC outputs the corresponding local oscillator reference frequency under the action of the control signal.

[0037] Output variable crystal oscillator 1 realizes integer or fractional frequency output.

[0038] In this application, in response to the high-frequency output requirements of the local oscillator source for satellite-borne equipment, for example, the remote sensing payload requires a local oscillator frequency above 10 GHz. In order to meet the output frequency requirements, the traditional single-loop phase-locked solution requires a complex phase-locked design, such as the use of CMOS circuit chips. This method is not only complex in circuit, but also uses CMOS for phase-locked processing, which is not reliable for satellite-borne equipment. In order to increase its reliability, redundant circuits need to be added to improve reliability, which further increases the complexity of the local oscillator design and increases the circuit cost.

[0039] Based on this, in the above scheme proposed by this application, based on the local oscillator frequency corresponding to the satellite-borne equipment, two phase-locked loops are used to decompose the required local oscillator frequency into two low-frequency outputs, and then the two low-frequency data are fused based on the mixing unit, thereby realizing the high-frequency output of the satellite-borne variable reference multi-loop phase-locked local oscillator source. In this process, the local oscillator reference frequency output by the variable crystal oscillator 1 is used. , and two phase-locked loops realize the high-frequency output of the local oscillator source. Since the frequency requirement of the phase-locked loop is reduced, its circuit complexity is also reduced, and the introduction of CMOS is avoided, which improves reliability and reduces circuit cost.

[0040] In addition, for the case where satellite-borne equipment uses decimal local oscillator frequencies, taking a certain remote sensing payload as an example, its local oscillator frequency is 14.84375 GHz. Compared with the traditional local oscillator source using SOI phase-locked chip which can only achieve integer frequency output, this application introduces an output variable crystal oscillator 1, which can achieve both decimal frequency output and integer frequency output.

[0041] In a preferred embodiment, see Figure 2 , Figure 2 FIG2 shows a second structural diagram of a satellite-borne variable reference multi-loop phase-locked local oscillator provided by an embodiment of the present application. Figure 2 As shown, the first phase-locked loop 21 includes a first phase detector 210, a first loop filter 211, a first voltage-controlled oscillator 212 and a frequency divider 213, where the frequency divider 213 is a 1 / 2 frequency divider.

[0042] Preferably, the first phase detector 210 receives the target feedback frequency from the mixing unit 3 The first phase detector 210 is based on the local oscillator reference frequency Target feedback frequency The difference between the two signals is used to generate a corresponding first error signal and send it to the first loop filter 211. The first loop filter 211 filters and smoothes the first error signal to generate a first control voltage and sends it to the first voltage-controlled oscillator 212. The first voltage-controlled oscillator 212 adjusts its corresponding output frequency according to the first control voltage to obtain the local oscillation frequency. .

[0043] In a specific embodiment, the first phase detector 210 uses a first fixed value, which is used to indicate the frequency division number of the first phase detector 210. The first phase detector 210 does not require an external controller for control. The first loop filter 211 uses an active proportional integral filter. The output frequency corresponding to the output end of the first voltage-controlled oscillator 212 is the local oscillator frequency ultimately output by the onboard variable reference multi-loop phase-locked local oscillator source. .

[0044] In another preferred embodiment, Figure 2 As shown, the first phase-locked loop sends the local oscillation frequency to the frequency divider 213 for frequency division processing to generate a first feedback frequency And send it to the mixing unit 3, where the first feedback frequency .

[0045] In a preferred embodiment, if Figure 2As shown, the second phase-locked loop 22 includes a second phase detector 220, a second loop filter 221 and a second voltage-controlled oscillator 222, and the second phase-locked loop 22 is in integer mode.

[0046] Preferably, the second phase detector 220 is based on the local oscillator reference frequency The difference between the second feedback frequency F2 and the second feedback frequency F2 generates a corresponding second error signal and sends it to the second loop filter 221. The second loop filter 221 filters and smoothes the second error signal to generate a second control voltage and sends it to the second voltage-controlled oscillator 222. The second voltage-controlled oscillator 222 adjusts its corresponding output frequency according to the second control voltage to obtain the adjusted second feedback frequency F2.

[0047] In the present application, the output frequencies of the first voltage-controlled oscillator 212 and the second voltage-controlled oscillator 222 are different.

[0048] In a specific embodiment, the second phase detector 220 uses a second fixed number, which is used to indicate the frequency division number of the second phase detector 220. The second phase detector 220 does not require an external controller for control. The second loop filter 221 uses an active proportional integral filter. The second feedback frequency F2 corresponding to the output end of the second voltage-controlled oscillator 222 is the reference frequency of the mixing unit 3.

[0049] In an optional embodiment, the frequency mixing unit 3 realizes the down-conversion function, takes the frequency output by the second phase-locked loop 22 as the reference frequency, and adjusts the output frequency (i.e., the local oscillator frequency) corresponding to the first phase-locked loop 21 based on the second feedback frequency F2. ) is down-converted to obtain the target feedback frequency FQ and sent to the feedback end of the first phase detector 210.

[0050] In a preferred embodiment, the target feedback frequency and the local oscillator reference frequency have the following configuration relationship:

[0051] (1)

[0052] Wherein, FQ represents the target feedback frequency output by the frequency mixing unit, Fref represents the local oscillator reference frequency, and M represents the first set value corresponding to the first phase detector 210, where M is an integer.

[0053] Specifically, the local oscillator reference frequency and the target feedback frequency FQ are both within the operating frequency range corresponding to the first phase detector 210. Furthermore, the local oscillator reference frequency The target feedback frequency FQ is consistent with the operating frequency range of the input terminal of the first phase detector 210 , and the target feedback frequency FQ is consistent with the operating frequency range of the feedback terminal of the first phase detector 210 .

[0054] In another preferred embodiment, the following configuration relationship exists between the reference frequency F1 output by the second phase-locked loop and the local oscillator reference frequency Fref:

[0055] (2)

[0056] Wherein, F2 represents the second feedback frequency output by the second phase-locked loop 22 , Fref represents the local oscillator reference frequency, and N represents the second set value corresponding to the second phase detector 220 , where N is an integer.

[0057] Specifically, the local oscillator reference frequency and the second feedback frequency F2 are both within the operating frequency range corresponding to the second phase detector 220. Furthermore, the local oscillator reference frequency The second feedback frequency F2 is consistent with the operating frequency range of the input end of the second phase detector 220 , and the second feedback frequency F2 is consistent with the operating frequency range of the feedback end of the second phase detector 220 .

[0058] In a specific embodiment, the frequency relationship corresponding to the frequency mixing unit 3 is as follows:

[0059] (3)

[0060] Then, combining formulas (1) to (3), we have:

[0061]

[0062] Further, we get:

[0063]

[0064] Preferably, Indicates the frequency division number corresponding to the frequency divider 213 in the first phase-locked loop. In a practical application, K=2 is taken. Then, for the local oscillator reference frequency Fref and the local oscillator frequency output by the onboard variable reference multi-loop phase-locked local oscillator source, , the following configuration relationship exists:

[0065]

[0066] In practical applications, the local oscillator frequency output by the satellite-borne equipment to the local oscillator source is According to the actual output requirements, appropriate N and M values ​​are selected in advance to determine the local oscillator reference frequency Fref corresponding to the output variable crystal oscillator. Specifically, the local oscillator reference frequency Fref is generally selected in the range of 70MHz~200MHz. The selection of N and M should ensure that the input and feedback ends of the phase detector are in line with their corresponding operating frequency range.

[0067] In a preferred embodiment, the phase-locked loop is a phase-locked loop integrated chip fabricated from silicon-on-insulator.

[0068] Specifically, the phase-locked loop uses a silicon-on-insulator chip to ensure the reliability of the local oscillator source running on the satellite-borne equipment.

[0069] In another preferred embodiment, Figure 2 As shown, the satellite-borne variable reference multi-loop phase-locked local oscillator source also includes a power supply 4 and an output filter 5, wherein the power supply 4 provides working power for the satellite-borne variable reference multi-loop phase-locked local oscillator source, and the output filter 5 filters the local oscillator frequency output by the first phase-locked loop to obtain a processed local oscillator frequency.

[0070] The components of the satellite-borne variable reference multi-loop phase-locked local oscillator provided in this application are selected from components with radiation resistance indicators to improve the reliability of satellite-borne operation.

[0071] This application is beneficial in that:

[0072] 1) Using a variable crystal oscillator output method to enable the onboard variable reference multi-loop phase-locked local oscillator source to support fractional frequency output;

[0073] 2) A multi-loop phase-locked solution is used to improve the system phase noise index and reduce the feedback frequency, making it possible to achieve a frequency output of more than 10 GHz using radiation-resistant index devices;

[0074] 3) For high-frequency output of the local oscillator frequency, compared with the traditional single-loop phase-locked solution, the circuit structure is simplified and the cost is saved;

[0075] 4) All phase-locked loops are integrated with phase-locked chips using silicon-on-insulator technology, which improves the reliability of the onboard variable reference multi-loop phase-locked local oscillator source.

[0076] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, the specific working process of the system and device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. In the several embodiments provided in this application, it should be understood that the disclosed system, device and method can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0077] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0078] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0079] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0080] The above are only specific embodiments of the present application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A satellite-borne variable reference multi-loop phase-locked local oscillator source, characterized in that: The onboard variable reference multi-loop phase-locked local oscillator source includes an output variable crystal oscillator, a first phase-locked loop, a second phase-locked loop and a frequency mixing unit. The output variable crystal oscillator generates a local oscillator reference frequency and sends the local oscillator reference frequency to the first phase-locked loop and the second phase-locked loop; The first phase-locked loop performs a mixing process based on the target feedback frequency output by the frequency mixing unit and the local oscillator reference frequency to generate a local oscillator frequency and a first feedback frequency corresponding to the onboard variable reference multi-loop phase-locked local oscillator source, and sends the first feedback frequency to the frequency mixing unit; The second phase-locked loop performs frequency mixing based on the local oscillator reference frequency and its own feedback mechanism to obtain a second feedback frequency and send it to the mixing unit; The frequency mixing unit performs down-conversion processing on the first feedback frequency and the second feedback frequency to generate a target feedback frequency and sends it to the first phase-locked loop; The first phase-locked loop includes a first phase detector, a first loop filter and a first voltage-controlled oscillator, and the second phase-locked loop includes a second phase detector, a second loop filter and a second voltage-controlled oscillator. The first phase-locked loop performs: a first phase detector receives a target feedback frequency from a frequency mixing unit; The first phase detector generates a corresponding first error signal based on the difference between the local oscillator reference frequency and the target feedback frequency and sends the signal to the first loop filter; The first loop filter filters and smoothes the first error signal to generate a first control voltage and sends the first control voltage to the first voltage-controlled oscillator; The first voltage-controlled oscillator adjusts its corresponding output frequency according to the first control voltage to obtain a local oscillation frequency; The second phase-locked loop executes: a second phase detector generates a corresponding second error signal based on a difference between a local oscillator reference frequency and a second feedback frequency and sends the signal to a second loop filter; The second loop filter filters and smoothes the second error signal to generate a second control voltage and sends the second control voltage to the second voltage-controlled oscillator; The second voltage-controlled oscillator adjusts its corresponding output frequency according to the second control voltage to obtain an adjusted second feedback frequency.

2. The satellite-borne variable reference multi-loop phase-locked local oscillator according to claim 1, characterized in that: The onboard variable reference multi-loop phase-locked local oscillator source also includes a frequency divider, The first phase-locked loop sends the local oscillator frequency to the frequency divider for frequency division processing, generates the first feedback frequency and sends it to the frequency mixing unit, and the first feedback frequency is half of the local oscillator frequency.

3. The satellite-borne variable reference multi-loop phase-locked local oscillator according to claim 1, characterized in that: The output variable crystal oscillator is: The customized crystal oscillator that controls the local oscillator reference frequency output by voltage value, Or a digital-to-analog converter, the local oscillator reference frequency output by the digital-to-analog converter is determined by the control signal output by the microcontroller.

4. The satellite-borne variable reference multi-loop phase-locked local oscillator according to claim 1, characterized in that: The following configuration relationship exists between the target feedback frequency and the local oscillator reference frequency: in, represents the target feedback frequency output by the mixing unit, Indicates the local oscillator reference frequency, represents the first set value corresponding to the first phase detector in the first phase-locked loop, is an integer.

5. The satellite-borne variable reference multi-loop phase-locked local oscillator according to claim 1, characterized in that: The second feedback frequency output by the second phase-locked loop and the local oscillator reference frequency have the following configuration relationship: in, represents the second feedback frequency output by the second phase-locked loop, Indicates the local oscillator reference frequency, represents the second set value corresponding to the second phase detector in the second phase-locked loop, is an integer.

6. The satellite-borne variable reference multi-loop phase-locked local oscillator according to claim 1, characterized in that: The following configuration relationship exists between the local oscillator reference frequency and the local oscillator frequency output by the onboard variable reference multi-loop phase-locked local oscillator source: in, Indicates the local oscillator reference frequency, Indicates the local oscillator frequency corresponding to the satellite-borne variable reference multi-loop phase-locked local oscillator source, Indicates the frequency division number corresponding to the frequency divider in the first phase-locked loop, is an integer, indicating the second setting number corresponding to the second phase-locked loop, is an integer representing the first setting number corresponding to the first phase-locked loop.

7. The satellite-borne variable reference multi-loop phase-locked local oscillator according to claim 1, characterized in that: The phase-locked loop is a phase-locked loop integrated chip made of silicon on insulator.

8. The satellite-borne variable reference multi-loop phase-locked local oscillator according to claim 1, characterized in that: The onboard variable reference multi-loop phase-locked local oscillator source also includes a power supply and an output filter. The power supply provides working power for the onboard variable reference multi-loop phase-locked local oscillator; The output filter performs filtering processing on the local oscillator frequency output by the first phase-locked loop to obtain a processed local oscillator frequency.

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