Large aperture microwave laser composite antenna modification method

Abstract

The application discloses a large-diameter microwave laser composite antenna modification method and relates to the technical field of space deep space exploration antennas. The method comprises the following steps: determining original panels to be removed; erecting a laser total station to establish an instrument coordinate system; measuring position data of the original panels; removing the original panels and manufacturing new panels; installing the new panels and adjusting the new panels; and installing laser antennas below the new panels. The application has the characteristics of simple implementation and low cost and can realize effective separation of laser signals and microwave signals in a microwave laser composite system.

Description

Technical Field

[0001] This invention relates to the field of aerospace deep space exploration antenna technology, and in particular to a method for modifying a large-aperture microwave laser composite antenna. Background Technology

[0002] In the field of deep space exploration, integrated microwave-laser telemetry, tracking, and command (TT&C) technology can solve the bottleneck problem of large-capacity data transmission and is an important research direction for future deep space exploration. Currently, large-aperture deep space antennas only have microwave TT&C capabilities and do not support laser communication. Adding laser communication equipment necessitates effective separation of laser and microwave signals. Effective separation of laser and microwave signals in a microwave-laser composite system is one of the key technical challenges. While a composite design of the laser antenna and the main reflector of a large-aperture microwave antenna can solve this problem, the installation of laser communication equipment affects the surface accuracy of the large-aperture microwave antenna, thus impacting its performance. Therefore, minimizing the impact on the performance of the existing large-aperture microwave antenna when upgrading laser communication functionality is crucial.

[0003] Chinese patent application CN201920351594.9, entitled "An Integrated Microwave and Optical Composite Antenna," proposes a method for modifying a microwave-laser composite antenna based on a small-aperture antenna. This method involves creating an opening in the main reflective panel of the microwave antenna and installing a light-transmitting reflective microwave panel at the opening. Small-aperture antennas have relatively low surface accuracy requirements, making this method suitable for their modification. However, for 35-meter large-aperture microwave antennas, the surface accuracy requirements are extremely high, making this modification method unsuitable for scenarios involving the modification of 35-meter large-aperture microwave-laser composite antennas. Summary of the Invention

[0004] In view of this, the present invention provides a method for modifying a large-aperture microwave-laser composite antenna, used to transform a deep-space large-aperture microwave antenna into a microwave-laser composite antenna. The present invention features simple implementation and low cost, and can achieve effective separation of laser signals and microwave signals in a microwave-laser composite system.

[0005] The objective of this invention is achieved as follows:

[0006] A method for modifying a large-aperture microwave-laser composite antenna, used to transform a deep-space large-aperture microwave antenna into a microwave-laser composite antenna, includes the following steps:

[0007] Step 1: Rotate the deep space large-aperture microwave antenna to the upward position, and use the panel at the intersection of the central body and the pitch fork as the original panel to be removed.

[0008] Step 2: Set up a laser total station at the center beam waveguide of the deep space large-aperture microwave antenna and establish the instrument coordinate system;

[0009] Step 3: Set target balls on the original panel and measure the coordinates of the four target balls using a laser total station; draw parallel lines on the original panel and the surrounding adjacent panels, and record the adjustment length of each adjusting screw on the original panel;

[0010] Step 4: Remove the original panel and make a new panel with the same shape and size as the original panel. The new panel can reflect microwave signals in the S, X, and Ka bands and transmit laser signals in the 1550nm band.

[0011] Step 5: Install the new panel and adjust it according to the markings and recorded data in Step 3;

[0012] Step 6: Install the laser antenna below the new panel, with the aperture of the laser antenna facing the new panel.

[0013] Furthermore, in step 2, the laser total station is fixed on the pressure plate on the waveguide flange ring, and the three screw holes on the pressure plate are selected as the reference to establish the instrument coordinate system.

[0014] Furthermore, in step 3, a cross mark is drawn at each of the four corners of the original panel at the adjustment screw, and a target ball is set at each cross mark.

[0015] Furthermore, in step 4, when removing the original panel, and in step 5, when installing the new panel, the panel is moved using pulleys mounted on the antenna sub-face support legs.

[0016] Furthermore, the new panel has a layered structure, including a bottom laser transmission layer, a top microwave reflection layer, and a middle isolation layer;

[0017] The laser transmission layer is made of quartz glass and has a sub-millimeter-scale array of holes with a diameter of 50 micrometers. The edges of the holes are coated with a SiO2 thin film, and the laser is coupled through a diffraction grating or waveguide.

[0018] The microwave reflective layer is covered with aluminum foil with a thickness of >50 micrometers and a slightly roughened surface to enhance broadband reflection;

[0019] The isolation layer is a low-loss polyimide medium with a thickness >1mm, which prevents microwave signals from penetrating to the laser transmission layer.

[0020] Furthermore, before installing the new panel in step 5, draw a crosshair and a flush line at the same location on the new panel, according to the markings on the original panel; the specific method for installing the new panel is as follows:

[0021] The new panel is hoisted into place using pulleys. The adjusting screw and nut are installed, and the length of the adjusting screw is adjusted to the previously recorded adjustment length so that the edge of the new panel is level with the edge of the surrounding adjacent panels. The alignment line of the new panel is then adjusted to align with the alignment line of the surrounding adjacent panels.

[0022] The laser total station was set up again on the pressure plate on the waveguide flange ring, and the three screw holes on the originally selected pressure plate were used as references to re-establish the instrument coordinate system and establish the mapping relationship between the old and new instrument coordinate systems.

[0023] Set target balls at the crosshairs on the new panel, measure the coordinates of each target ball using a laser total station, and then repeatedly fine-tune the adjusting screws until the coordinates of each target ball are adjusted to be no more than 0.2mm different from the original coordinates.

[0024] The present invention has the following beneficial effects:

[0025] 1. The microwave-laser composite antenna implemented in this invention has minimal impact on the performance of the microwave antenna due to its primary reflector, which facilitates the reception and transmission of laser signals.

[0026] 2. The present invention uses a dual-color panel that can transmit laser signals and reflect microwave signals, thereby effectively separating optical signals and microwave signals.

[0027] 3. This invention facilitates the upgrading and modification of existing antennas. During the modification process, the old panel is easy to disassemble and assemble, and the area of ​​the installed dual-color panel is very small, resulting in low cost.

[0028] 4. The laser antenna in this invention is easy to install, which is beneficial for upgrading the laser communication function of large-aperture antennas. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the installation position of the laser total station in an embodiment of the present invention.

[0030] Figure 2 This is a schematic diagram of the disassembly and assembly panel in an embodiment of the present invention.

[0031] Figure 3 This is a schematic diagram of the layered structure of the two-color panel in an embodiment of the present invention. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings.

[0033] A method for modifying a large-aperture microwave-laser composite antenna, used to transform a deep-space large-aperture microwave antenna into a microwave-laser composite antenna, includes the following steps:

[0034] Step 1: Rotate the deep space large-aperture microwave antenna to the upward position, and use the panel at the intersection of the central body and the pitch fork as the original panel to be removed.

[0035] Step 2: Set up a laser total station at the center beam waveguide of the deep space large-aperture microwave antenna and establish the instrument coordinate system;

[0036] Before removing the panel to be removed, use a laser total station to measure the location data of the panel to be removed, in preparation for the installation of a replacement panel. The laser total station is fixed to the pressure plate on the waveguide flange ring, and three screw holes on the pressure plate are selected as references to establish the instrument coordinate system.

[0037] The flange ring serves as the reference for installing and adjusting the main reflector. Bird netting at the beamguide opening is mounted on the flange ring using a clamping plate. The 35-meter deep-space large-aperture antenna uses a beamguide design, and the beamguide flange ring is the reference for installing and adjusting the antenna's main reflector. Bird netting is installed on the antenna surface. The laser total station's installation location is referenced... Figure 1 It is used to measure the precise position of disassembled panels. The laser total station has a ranging accuracy of 30μm ± 5ppm.

[0038] Step 3: Set target balls on the original panel and measure the coordinates of the four target balls using a laser total station; draw parallel lines on the original panel and the surrounding adjacent panels, and record the adjustment length of each adjusting screw on the original panel;

[0039] Specifically, a crosshair is drawn at each of the four adjustment screws on the original panel, and a target ball is placed at each crosshair. The coordinate values ​​of these target balls are then measured. The adjustment screws are screws on the antenna frame structure used to fix and adjust the height and level of the antenna panel, and are a standard structure in existing antennas.

[0040] Step 4: Remove the original panel and make a new panel with the same shape and size as the original panel (i.e., a two-color panel). The new panel can reflect microwave signals in the S, X, and Ka bands and transmit laser signals in the 1550nm band.

[0041] Specifically, eight flush lines are drawn on the removed panel and its adjacent panels to serve as a baseline for rough adjustment during the subsequent installation of the two-tone panel. Only the adjusting screws and nuts are removed to preserve the original appearance as much as possible. The positions of the eight flush lines are as follows: Figure 2 This location serves as the reference point for installing the new panel, ensuring that the new panel's location matches the old panel's installation location.

[0042] The original panel was removed by moving it using pulleys mounted on the antenna sub-face support legs.

[0043] Step 5: Install the new panel and adjust it according to the markings and recorded data from Step 3;

[0044] When installing a new panel, the panel is also moved using pulleys mounted on the antenna sub-face support legs.

[0045] The new panel has a layered structure, such as Figure 3As shown, it includes a bottom laser transmission layer, a top microwave reflection layer, and a middle isolation layer. The laser transmission layer is made of quartz glass and has a sub-millimeter-scale array of holes with a diameter of 50 micrometers. The laser is coupled through a diffraction grating or waveguide, and an anti-reflection coating is added. A SiO2 thin film is deposited at the edge of the holes. The microwave reflection layer is covered with aluminum foil with a thickness >50 micrometers and a slightly roughened surface to enhance broadband reflection. The isolation layer is made of polyimide low-loss dielectric with a thickness >1 mm to prevent microwave signals from penetrating to the transmission layer.

[0046] Before installing the new panel, draw a crosshair and a flush line in the same position on the new panel, following the markings on the original panel. The specific installation method for the new panel is as follows:

[0047] The new panel is hoisted into place using pulleys. The adjusting screw and nut are installed, and the length of the adjusting screw is adjusted to the previously recorded adjustment length so that the edge of the new panel is consistent with the edge of the surrounding adjacent panels. The alignment line of the new panel is then adjusted to align with the alignment line of the surrounding adjacent panels.

[0048] The laser total station was set up again on the pressure plate on the waveguide flange ring, and the three screw holes on the originally selected pressure plate were used as the reference to re-establish the instrument coordinate system and establish the mapping relationship between the old and new instrument coordinate systems.

[0049] Set target balls at the crosshairs on the new panel, measure the coordinates of each target ball using a laser total station, and then repeatedly fine-tune the adjusting screws until the coordinates of each target ball are adjusted to be no more than 0.2mm different from the original coordinates.

[0050] The total accuracy of the main reflector of the 35-meter aperture deep space antenna is 0.3 mm (root mean square error). Adjusting the antenna panel reset accuracy to within 0.2 mm will not affect the total accuracy of the antenna main reflector.

[0051] Step 6: Install the laser antenna below the new panel, with the aperture of the laser antenna facing the new panel.

[0052] This method only requires removing a panel of approximately 1 square meter from the original antenna's main reflector. Alternatively, appropriately sized openings can be made on the antenna panel, and a dual-color panel supporting the transmission of laser signals and the reflection of microwave signals can be installed at these openings. This method ensures both antenna aperture efficiency and prevents the optical antenna aperture from being obstructed.

[0053] In summary, this invention replaces the original panel of the microwave antenna with a dual-color panel that transmits laser signals and reflects microwave signals, achieving effective separation of laser and microwave signals. This method has minimal impact on the performance of the microwave antenna, facilitating laser signal reception and transmission. The dual-color panel can transmit laser signals and reflect microwave signals, thus effectively separating optical and microwave signals. During the installation of a laser communication system on a large-aperture microwave antenna, the old antenna panel is easy to disassemble and assemble, and the newly installed dual-color panel has a small area and low cost. The laser antenna is easy to install, which is beneficial for upgrading the laser communication function of existing deep-space large-aperture microwave antenna systems.

Claims

1. A method for modifying a large-aperture microwave laser composite antenna, characterized in that, The steps for converting a large-aperture deep-space microwave antenna into a microwave-laser composite antenna include: Step 1: Rotate the deep space large-aperture microwave antenna to the upward position, and use the panel at the intersection of the central body and the pitch fork as the original panel to be removed. Step 2: Set up a laser total station at the center beam waveguide of the deep space large-aperture microwave antenna and establish the instrument coordinate system; Step 3: Set target balls on the original panel and measure the coordinates of the four target balls using a laser total station; draw parallel lines on the original panel and the surrounding adjacent panels, and record the adjustment length of each adjusting screw on the original panel; Step 4: Remove the original panel and manufacture a new panel with the same shape and size as the original panel. The new panel can reflect microwave signals in the S, X, and Ka bands and transmit laser signals in the 1550nm band. The new panel has a layered structure, including a bottom laser transmission layer, a top microwave reflection layer, and an intermediate isolation layer. The laser transmission layer is made of quartz glass and has a sub-millimeter-scale array of holes with a diameter of 50 micrometers. The edges of the holes are coated with a SiO2 thin film, and the laser is coupled through a diffraction grating or waveguide. The microwave reflective layer is covered with aluminum foil with a thickness of >50 micrometers and a slightly roughened surface to enhance broadband reflection; The isolation layer is a low-loss polyimide medium with a thickness >1mm, which prevents microwave signals from penetrating to the laser transmission layer. Step 5: Install the new panel and adjust it according to the markings and recorded data from Step 3; Step 6: Install the laser antenna below the new panel, with the aperture of the laser antenna facing the new panel.

2. The method for modifying a large-aperture microwave laser composite antenna according to claim 1, characterized in that, In step 2, the laser total station is fixed on the pressure plate on the waveguide flange ring, and the three screw holes on the pressure plate are selected as the reference to establish the instrument coordinate system.

3. The method for modifying a large-aperture microwave laser composite antenna according to claim 2, characterized in that, In step 3, draw a cross mark at each of the four adjustment screws on the original panel, and set a target ball at each cross mark.

4. The method for modifying a large-aperture microwave laser composite antenna according to claim 3, characterized in that, In step 4, when removing the original panel, and in step 5, when installing the new panel, the panel is moved using pulleys mounted on the antenna sub-face support legs.

5. The method for modifying a large-aperture microwave laser composite antenna according to claim 1, characterized in that, Before installing the new panel in step 5, draw a crosshair and a flush line in the same position on the new panel, following the markings on the original panel. The specific method for installing the new panel is as follows: The new panel is hoisted into place using pulleys. The adjusting screw and nut are installed, and the length of the adjusting screw is adjusted to the previously recorded adjustment length so that the edge of the new panel is consistent with the edge of the surrounding adjacent panels. The alignment line of the new panel is then adjusted to align with the alignment line of the surrounding adjacent panels. The laser total station was set up again on the pressure plate on the waveguide flange ring, and the three screw holes on the originally selected pressure plate were used as the reference to re-establish the instrument coordinate system and establish the mapping relationship between the old and new instrument coordinate systems. Set target balls at the crosshairs on the new panel, measure the coordinates of each target ball using a laser total station, and then repeatedly fine-tune the adjusting screws until the coordinates of each target ball are adjusted to be no more than 0.2mm different from the original coordinates.

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