Satellite-borne VLBI frequency conversion and data acquisition terminal and use method

Abstract

The invention relates to a satellite-borne VLBI frequency conversion and data acquisition terminal and a use method, and the terminal comprises a frequency conversion device, a data processing device and a data interaction device. The frequency conversion device is used for receiving a radio frequency signal of 8-9 GHz and outputting an intermediate frequency signal of 100-1000 MHz through frequency conversion; the data processing device is connected with the frequency conversion device and is used for sampling and processing the intermediate frequency signal; and the data interaction device is connected with the data processing device and is used for outputting the processed data to an on-satellite solid memory and realizing instruction interaction. Compared with the prior art, the method has the advantages that signal interference is effectively reduced, signal quality is improved, acquired data are more accurate, energy consumption and emission cost of satellites are reduced while strict limitation of satellite carrying on equipment is met, and stability and reliability are improved.

Description

Technical Field

[0001] This invention relates to the field of spaceborne radio astronomy, specifically to a VLBI frequency conversion and data acquisition terminal for lunar orbit satellites and its usage method. Background Technology

[0002] In the field of radio astronomy, Very Long Baseline Interferometry (VLBI) technology, with its high resolution and high sensitivity, has become an important tool for exploring the mysteries of the universe. By working in concert with multiple radio telescopes, VLBI can overcome the limitations of a single telescope, acquiring detailed structures and faint signals from celestial objects, providing crucial data for research in astronomy, earth sciences, physics, and many other fields. However, most traditional VLBI facilities are deployed on the ground, and are limited by the Earth's environment and the length of the observation baseline, facing bottlenecks in improving observation range and resolution.

[0003] With the development of aerospace technology, spaceborne VLBI systems have emerged. By mounting VLBI equipment on satellites and leveraging the unique observation perspective and ultra-long baseline advantages of satellites in space, observation resolution can be significantly improved, filling gaps in ground-based observations, especially in the observation of deep-space objects and low-latitude regions, where it has irreplaceable advantages. Spaceborne VLBI systems not only overcome the line-of-sight obstruction problem of geostationary satellites but also utilize the low noise and long baseline distance of the space environment to achieve higher spatial resolution and more sensitive detection capabilities.

[0004] Satellites impose stringent requirements on the size, weight, power consumption, and reliability of equipment, specifically:

[0005] 1. Size and power consumption limitations: The satellite payload must meet stringent weight (≤4.2kg) and power consumption (≤60W) constraints;

[0006] 2. Anti-interference capability: Extreme temperature fluctuations in lunar orbit (phase stability ≤ 5℃ / hour) and electromagnetic interference (EMI ≤ 27dBμV / m@8-9GHz) place higher demands on signal processing stability.

[0007] 3. High-frequency signal processing efficiency: Frequency conversion and acquisition of 8-9GHz RF signals require high-precision local oscillators (phase noise ≤ -110dBc / Hz@1MHz) and high-speed ADCs (2048Msps / channel).

[0008] When the radio frequency signal is 8-9 GHz, existing spaceborne VLBI systems, while meeting these requirements, suffer from problems such as insufficient signal processing accuracy, limited anti-interference capability, and poor data transmission stability, specifically including:

[0009] 1. Existing spaceborne VLBI systems require a large amount of hardware resources and high-performance processors to process high-frequency signals, resulting in high system complexity and high cost, making it difficult to meet the stringent requirements of satellite payloads;

[0010] 2. Existing equipment is not stable enough in signal processing and reliable in data transmission when faced with extreme temperature fluctuations and electromagnetic interference in lunar orbit. It is easily affected by external environmental interference, which affects the accuracy of observation.

[0011] 3. Most traditional VLBI equipment is deployed on the ground. Due to the limitations of the Earth's environment and the length of the observation baseline, it faces bottlenecks in terms of improving the observation range and resolution, making it difficult to achieve high-precision observations of deep-sky objects and low-latitude regions.

[0012] 4. Existing frequency conversion and data acquisition terminals are insufficient in terms of signal-to-noise ratio and data fidelity in data acquisition and recording systems, making it difficult to meet the needs of higher precision observation.

[0013] In summary, existing spaceborne VLBI systems have many shortcomings, which restrict the further development and application of spaceborne VLBI technology. Summary of the Invention

[0014] The purpose of this invention is to overcome the shortcomings of the existing technology by providing a spaceborne VLBI frequency conversion and data acquisition terminal and method for satellite 8-9GHz radio frequency signals. This effectively reduces signal interference, improves signal quality, and acquires more accurate data. Furthermore, while meeting the strict limitations on satellite equipment, it reduces satellite energy consumption and launch costs, and improves stability and reliability.

[0015] In a first aspect, the present invention provides a spaceborne VLBI frequency converter and data acquisition terminal, comprising: a frequency converter, a data processing device, and a data interaction device;

[0016] The frequency converter is used to receive 8-9GHz radio frequency signals and output intermediate frequency signals through frequency conversion;

[0017] The data processing device is connected to the frequency converter and is used to sample and process the intermediate frequency signal;

[0018] The data interaction device is connected to the data processing device and is used to output the processed data to the on-board storage and realize command interaction.

[0019] Preferably, the frequency converter includes: a radio frequency signal receiving channel, a frequency conversion link, and a cryogenic unit power supply and telemetry module;

[0020] The radio frequency signal receiving channel is used to receive radio frequency signals of 8-9 GHz;

[0021] The frequency conversion link is connected to the radio frequency signal receiving channel and is used to convert the 8-9 GHz radio frequency signal to output an intermediate frequency signal.

[0022] The cryogenic unit power supply and telemetry module is connected to the data processing device and is used to power the cryogenic electronic unit and / or monitor the electrical performance parameters of the cryogenic electronic unit.

[0023] Preferably, the frequency converter further includes a noise suppressor connected to the frequency converter link for suppressing noise and harmonics in the intermediate frequency signal.

[0024] Preferably, the noise suppressor includes: a mirror suppression mixer and a low phase noise local oscillator, supporting dynamic gain adjustment.

[0025] Preferably, the radio frequency signal receiving channel includes dual input channels and dual output channels, and / or the frequency conversion link is a dual-channel frequency conversion link, with each channel having one polarization.

[0026] Preferably, the intermediate frequency signal is 100-1000MHz, and / or clutter ≤-50dBc, and / or harmonics ≤-40dBc, and / or image rejection ≥35dB, and / or the low phase noise local oscillator is 11.5GHz, and / or the local oscillator phase noise ≤-110dBc / Hz@1MHz, and / or the gain dynamic adjustment is 30-60dB, and / or the step is ≤5dB; the sampling rate is 2048Msps, the channel transmission capacity is ≥1.2Gbps, and the maximum output data rate is 4096Mbps.

[0027] Preferably, the cryogenic unit power supply and telemetry module provides a +5±0.2V power supply to the cryogenic electronic unit.

[0028] Preferably, the data processing device includes a data processing module and an analog-to-digital converter;

[0029] The analog-to-digital converter is connected to the frequency converter.

[0030] The data processing module is connected to the analog-to-digital converter and is used to process intermediate frequency signals and output the processed data to the data interaction device.

[0031] Secondly, this application provides a method for using a spaceborne VLBI frequency converter and data acquisition terminal, including:

[0032] It receives 8-9GHz radio frequency signals and outputs 100-1000MHz intermediate frequency signals through frequency conversion;

[0033] The intermediate frequency signal is sampled and processed;

[0034] The processed data is output to the on-board storage and command interaction is achieved.

[0035] Compared with the prior art, the present invention has the following advantages:

[0036] Performance Improvement: The terminal of this invention improves the frequency conversion accuracy and data acquisition accuracy of radio frequency signals by optimizing the design of the frequency conversion device and data processing device. For example, when the frequency conversion module has an image rejection ≥35dB, spurious rejection ≤ -50dBc@0dBm output, and harmonic rejection ≤ -40dBc@0dBm output, signal interference is effectively reduced and signal quality is improved. The data processing device has an effective bit width (ENOB) ≥6.0 and a spurious-free dynamic range (SFDR) ≥40dB, enabling the acquisition of more accurate data and providing more reliable evidence for subsequent scientific research.

[0037] Meets satellite requirements: The design has been optimized in terms of size, weight and power consumption, with a single unit weight of ≤4.2kg and a single unit power consumption of ≤60W, meeting the strict restrictions on satellite equipment and reducing satellite energy consumption and launch costs;

[0038] Enhanced reliability: Phase stability ≤5℃ / hour, EMI suppression ≤27dBμV / m@8-9GHz, adaptable to the extreme environment of lunar orbit; equipped with complete telemetry and remote control functions, the working status of the equipment can be monitored in real time through telemetry parameters, such as the power-on and power-off status of each module, local oscillator lock-in indication, etc.; the various functions of the equipment can be precisely controlled through remote control commands, which improves the stability and reliability of the equipment and ensures the smooth progress of data processing and transmission. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the system architecture of the present invention;

[0040] Figure 2 This is a circuit diagram of the data processing device of the present invention;

[0041] Figure 3 This is a schematic diagram of the method flow of the present invention;

[0042] Explanation of markings in the diagram:

[0043] The system includes a frequency converter 100, a radio frequency signal receiving channel 110, a frequency converter link 120, a cryogenic unit power supply and telemetry module 130, a noise suppressor 140, a mirror suppression mixer 141, a low phase noise local oscillator 142, a data processing device 200, a data processing module 210, an analog-to-digital converter 220, a data interaction device 300, and a cryogenic electronic unit 400. Detailed Implementation

[0044] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0045] The purpose of this invention is to overcome the shortcomings of the existing technology by providing a spaceborne VLBI frequency conversion and data acquisition terminal and method for satellite 8-9GHz radio frequency signals. This effectively reduces signal interference, improves signal quality, and acquires more accurate data. Furthermore, while meeting the strict limitations on satellite equipment, it reduces satellite energy consumption and launch costs, and improves stability and reliability.

[0046] Example 1

[0047] like Figure 1 As shown, a spaceborne VLBI frequency conversion and data acquisition terminal includes a frequency converter 100, a data processing unit 200, and a data interaction unit 300. The frequency converter 100 is used to receive 8-9 GHz radio frequency signals and output intermediate frequency signals through frequency conversion. The frequency converter 100 includes a radio frequency signal receiving channel 110, a frequency conversion link 120, a cryogenic unit power supply and telemetry module 130, and a noise suppressor 140. The radio frequency signal receiving channel 110 is used to receive 8-9 GHz radio frequency signals; the radio frequency signal receiving channel 110 includes dual input channels and dual output channels, each channel corresponding to one polarization; the frequency conversion link 120 is connected to the radio frequency signal receiving channel 110 and is used to convert the 8-9 GHz radio frequency signals to output intermediate frequency signals; the frequency conversion link 120 is a dual-channel frequency conversion link 120, each channel having one polarization; the noise suppressor 140 is connected to the frequency conversion link 120 and is used to suppress noise and harmonics in the intermediate frequency signals. The noise suppressor 140 includes an image-suppression mixer 141 and a low-phase-noise local oscillator 142, supporting dynamic gain adjustment. The intermediate frequency signal is 100-1000MHz, with clutter ≤-50dBc, harmonics ≤-40dBc, and image suppression ≥35dB. The low-phase-noise local oscillator is 11.5GHz, with local oscillator phase noise ≤-110dBc / Hz@1MHz, and dynamic gain adjustment of 30-60dB with a step size ≤5dB. The cryogenic unit power supply and telemetry module 130 is connected to the data processing device 200 and is used to power the cryogenic electronic unit 400 and / or monitor the electrical performance parameters of the cryogenic electronic unit 400; the cryogenic unit power supply and telemetry module 130 provides +5±0.2V power to the cryogenic electronic unit 400.

[0048] like Figure 2As shown, the data processing device 200 is connected to the frequency converter 100 and is used to sample and process the intermediate frequency signal. The data processing device 200 includes a data processing module 210 and an analog-to-digital converter 220. The analog-to-digital converter 220 is connected to the frequency converter 100, receives the intermediate frequency signal, and performs analog-to-digital conversion. The data processing module 210 is connected to the analog-to-digital converter 220, and is used to process the intermediate frequency signal and output the processed data to the data interaction device 300.

[0049] The data interaction device 300 is connected to the data processing device 200 and is used to output processed data to on-board solid-state storage and to realize command interaction. The data interaction device 300 receives processed data output by the data processing module 210 and transmits this data to the on-board solid-state storage device for storage. At the same time, the data interaction device 300 is also responsible for command interaction with other systems on the satellite, receiving control commands and transmitting them to the data processing device 200 to control the working status of the entire frequency converter and data acquisition terminal.

[0050] During operation, the onboard VLBI frequency converter and data acquisition terminal first receives 8-9 GHz radio frequency signals through the radio frequency signal receiving channel 110 of the frequency converter 100, and then converts the radio frequency signals into 100-1000 MHz intermediate frequency signals through the frequency conversion link 120. During the frequency conversion process, the noise suppressor 140 suppresses noise and harmonics in the signal to ensure signal quality. The frequency-converted intermediate frequency signal is sent to the data processing device 200, sampled by the analog-to-digital converter 220, and then processed by the data processing module 210. The processed data is output to the onboard storage through the data interaction device 300, enabling command interaction with other systems on the satellite. Throughout the process, the cryogenic unit power supply and telemetry module 130 provides a stable +5±0.2V power supply to the cryogenic electronics unit 400 and monitors its electrical performance parameters to ensure stable system operation.

[0051] Compared with the prior art, the present invention has the following advantages:

[0052] Performance Improvement: The terminal of this invention improves the frequency conversion accuracy and data acquisition accuracy of radio frequency signals by optimizing the design of the frequency conversion device and data processing device. For example, when the frequency conversion module has an image rejection ≥35dB, spurious rejection ≤ -50dBc@0dBm output, and harmonic rejection ≤ -40dBc@0dBm output, signal interference is effectively reduced and signal quality is improved. The data processing device has an effective bit width (ENOB) ≥6.0 and a spurious-free dynamic range (SFDR) ≥40dB, enabling the acquisition of more accurate data and providing more reliable evidence for subsequent scientific research.

[0053] Meets satellite requirements: The design has been optimized in terms of size, weight and power consumption, with a single unit weight of ≤4.2kg and a single unit power consumption of ≤60W, meeting the strict restrictions on satellite equipment and reducing satellite energy consumption and launch costs;

[0054] Enhanced reliability: Phase stability ≤5℃ / hour, EMI suppression ≤27dBμV / m@8-9GHz, adaptable to the extreme environment of lunar orbit; equipped with complete telemetry and remote control functions, the working status of the equipment can be monitored in real time through telemetry parameters, such as the power-on and power-off status of each module, local oscillator lock-in indication, etc.; the various functions of the equipment can be precisely controlled through remote control commands, which improves the stability and reliability of the equipment and ensures the smooth progress of data processing and transmission.

[0055] Example 2:

[0056] This embodiment provides a method for using a spaceborne VLBI frequency converter and data acquisition terminal, which is applied to the spaceborne VLBI frequency converter and data acquisition terminal described in Embodiment 1.

[0057] like Figure 3 As shown, the method of use includes the following steps:

[0058] S001 receives 8-9GHz radio frequency signals and outputs 100-1000MHz intermediate frequency signals through frequency conversion;

[0059] In this step, the radio frequency signal receiving channel 110 of the frequency converter 100 receives 8-9 GHz radio frequency signals. This receiving channel includes dual input channels and dual output channels, each corresponding to a polarization. The received radio frequency signals are frequency-converted through the dual-channel frequency conversion link 120 to output intermediate frequency signals of 100-1000 MHz. During the frequency conversion process, the noise suppressor 140 suppresses noise and harmonics in the signal to ensure signal quality. The noise suppressor 140 includes an image suppression mixer 141 and a low-phase-noise local oscillator 142, supporting dynamic gain adjustment. During the frequency conversion process, noise is controlled at ≤-50 dBc, harmonics are controlled at ≤-40 dBc, image suppression reaches ≥35 dB, an 11.5 GHz noise local oscillator is used, the local oscillator phase noise is controlled at ≤-110 dBc / Hz@1 MHz, and the dynamic gain adjustment range is 30-60 dB with a step of ≤5 dB.

[0060] S002, sampling and processing of intermediate frequency signals;

[0061] In this step, the data processing unit 200 receives the intermediate frequency signal output by the frequency converter 100. First, the analog-to-digital converter 220 samples the intermediate frequency signal, converting the analog signal into a digital signal. Then, the data processing module 210 processes the sampled digital signal, including data format conversion, data compression, and other operations, to generate a data format that meets the requirements of subsequent processing.

[0062] S003 outputs the processed data to the on-board storage and enables command interaction;

[0063] In this step, the data interaction device 300 receives the data processed by the data processing module 210 and transmits this data to the onboard solid-state storage device for storage. Simultaneously, the data interaction device 300 interacts with other onboard systems, receiving control commands and transmitting them to the data processing device 200 to control the operating status of the entire frequency converter and data acquisition terminal. Command interaction includes receiving observation mission commands, sending equipment status information, and receiving parameter adjustment commands, etc.

[0064] Throughout the operation, the cryogenic unit power supply and telemetry module 130 provides a stable +5±0.2V power supply to the cryogenic electronics unit 400 and monitors its electrical performance parameters to ensure stable system operation. Through this method, the spaceborne VLBI frequency converter and data acquisition terminal can effectively receive, process, and store radio astronomy observation data, providing reliable data support for spaceborne VLBI observation missions.

[0065] The above specific examples of the present invention have further illustrated the purpose, technical solution and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A spaceborne VLBI frequency converter and data acquisition terminal, characterized in that, include: Frequency converter, data processing device and data interaction device; The frequency converter is used to receive 8-9GHz radio frequency signals and output intermediate frequency signals through frequency conversion; The data processing device is connected to the frequency converter and is used to sample and process the intermediate frequency signal; The data interaction device is connected to the data processing device and is used to output the processed data to the on-board storage and realize command interaction.

2. The spaceborne VLBI frequency converter and data acquisition terminal according to claim 1, characterized in that, The frequency converter includes: a radio frequency signal receiving channel, a frequency conversion link, and a cryogenic unit power supply and telemetry module; The radio frequency signal receiving channel is used to receive radio frequency signals of 8-9 GHz; The frequency conversion link is connected to the radio frequency signal receiving channel and is used to convert the 8-9 GHz radio frequency signal to output an intermediate frequency signal. The cryogenic unit power supply and telemetry module is connected to the data processing device and is used to power the cryogenic electronic unit and / or monitor the electrical performance parameters of the cryogenic electronic unit.

3. The spaceborne VLBI frequency converter and data acquisition terminal according to claim 2, characterized in that, The frequency converter further includes a noise suppressor connected to the frequency conversion link for suppressing noise and harmonics in the intermediate frequency signal.

4. The spaceborne VLBI frequency converter and data acquisition terminal according to claim 3, characterized in that, The noise suppressor includes a mirror-suppressed mixer and a low-phase-noise local oscillator, supporting dynamic gain adjustment.

5. A spaceborne VLBI frequency converter and data acquisition terminal according to claim 4, characterized in that, The radio frequency signal receiving channel includes dual input channels and dual output channels, and / or the frequency conversion link is a dual-channel frequency conversion link, with each channel having one polarization.

6. The spaceborne VLBI frequency converter and data acquisition terminal according to claim 5, characterized in that, The intermediate frequency signal is 100-1000MHz, and / or clutter ≤ -50dBc, and / or harmonics ≤ -40dBc, and / or image rejection ≥ 35dB, and / or the low phase noise local oscillator is 11.5GHz, and / or local oscillator phase noise ≤ -110dBc / Hz@1MHz, and / or gain dynamic adjustment 30-60dB, and / or step ≤ 5dB; the sampling rate is 2048Msps, the RF signal receiving channel transmission capacity is ≥ 1.2Gbps, and the maximum output data rate is 4096Mbps.

7. A spaceborne VLBI frequency converter and data acquisition terminal according to claim 2, characterized in that, The cryogenic unit power supply and telemetry module provides +5±0.2V power to the cryogenic electronic unit.

8. A spaceborne VLBI frequency converter and data acquisition terminal according to claim 2, characterized in that, The data processing device includes a data processing module and an analog-to-digital converter; The analog-to-digital converter is connected to the frequency converter. The data processing module is connected to the analog-to-digital converter and is used to process intermediate frequency signals and output the processed data to the data interaction device.

9. A method of using the spaceborne VLBI frequency converter and data acquisition terminal as described in claims 1-8, characterized in that, include: It receives 8-9GHz radio frequency signals and outputs 100-1000MHz intermediate frequency signals through frequency conversion; The intermediate frequency signal is sampled and processed; The processed data is output to the on-board storage and command interaction is achieved.

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