Thermal control film with energy selection characteristic for satellites

Abstract

The invention discloses a thermal control film with an energy selection characteristic for satellites, the thermal control film with the energy selection characteristic for satellites is of a multi-layer composite structure, the multi-layer composite structure comprises a thermal control protection layer, a substrate layer and an energy selection layer, the thermal control protection layer is attached to one side of the substrate layer, and the other side of the substrate layer is attached to the energy selection layer; the thermal control protection layer, the substrate layer and the energy selection layer are all of a thin film structure. The periodic structure of the diode is adopted on the energy selection layer, on one hand, the solar spectrum is emitted, the solar absorptivity of the thermal control film for the satellite with the energy selection characteristic is received, the thermal control performance is improved, on the other hand, the surface impedance characteristic of the energy selection layer can be changed according to the intensity of an incident electromagnetic signal, and the thermal control performance is improved. Therefore, the surface impedance characteristic of the thermal control film for the satellite with the energy selection characteristic is changed, the space strong electromagnetic environment protection capability of weak electromagnetic signal low-loss passing and strong electromagnetic signal suppression transmission is realized, and the defects in the prior art are overcome.

Description

Technical Field

[0001] The present invention belongs to but is not limited to the field of aerospace technology, and relates to a thermal control film, and in particular to a thermal control film for satellites with energy selection characteristics. Background Art

[0002] The satellite in orbit is in a vacuum environment with drastic changes in temperature. Thermal control films have become one of the most basic means of passive thermal control for spacecraft due to their good thermal insulation properties. They are widely used to cover the surface of spacecraft and the front end of antennas. With the development of satellite antenna technology, the requirements for thermal control films at the front end of antennas are getting higher and higher.

[0003] In addition, as satellite communications, navigation, remote sensing and reconnaissance services all place higher and higher demands on stable, reliable and real-time communication connections, the strong electromagnetic environment in space will seriously affect the reliable connection of satellites. High-power electromagnetic attacks can enter the equipment through the "front door" and "back door" to interfere with and damage the electronic information system. The protection of the "back door" is generally achieved through shielding or absorption, while the protection of the "front door" (entering the system through the antenna of the electronic information system) cannot be achieved by shielding or other means due to the need for normal business operations.

[0004] The shortcomings of the current existing technology: there is a lack of protection technology for the strong electromagnetic environment in space for thermal control films for satellites. For example, the Chinese patent "A germanium-plated film antenna cover structure for satellite-borne antennas" with publication number CN207074709U, which was published on March 6, 2018, discloses a germanium-plated film antenna cover structure for satellite-borne antennas, which relates to the field of antenna covers for satellite-borne active phased array antennas. The use of germanium-plated films has high wave transmittance and good heat insulation effect, but does not have the ability to protect against strong electromagnetic environments in space. The Chinese patent "Star Surface Multilayer Thermal Insulation Component with Strong Electromagnetic Environment Protection Capability" with publication number CN113428385B, which was published on August 2, 2021, discloses a strong electromagnetic-resistant reinforced mask component, which adds a layer of indium tin oxide film on the surface of the thermal control film to achieve protection against "backdoor" coupled microwaves. This technology has good "backdoor" protection performance, but normal electromagnetic signals cannot pass through the multi-layer thermal insulation component and cannot be used for the protection of the "front door" (antenna front end). Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a satellite thermal control film with energy selection characteristics to solve the technical problems in the prior art that the satellite thermal control film with energy selection characteristics has a high overall solar absorption rate and has no protection against strong electromagnetic environments in space.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0007] A thermal control film for satellites with energy selection characteristics, characterized in that the thermal control film for satellites with energy selection characteristics is a multi-layer composite structure, the multi-layer composite structure includes a thermal control protective layer, a base layer and an energy selection layer, the thermal control protective layer is bonded to one side of the base layer, and the other side of the base layer is bonded to the energy selection layer; the thermal control protective layer, base layer and energy selection layer are all thin film structures.

[0008] The present invention also has the following technical features:

[0009] The thermal control protection layer is composed of a metal layer and a polyimide layer. The metal layer is made of germanium or doped germanium. The thickness of the metal layer is 100nm-10um; the thickness of the polyimide layer is 10um-150um.

[0010] The solar absorption ratio of the satellite thermal control film with energy selection characteristics is not greater than 0.45.

[0011] The energy selection layer adopts a diode to adjust the surface impedance characteristics of the energy selection layer.

[0012] The periodic structure of the energy selection layer is one or a combination of a cross structure, an annular gap, a cross gap and a straight structure.

[0013] The interval of the periodic structure of the energy selection layer is less than half of the wavelength of the service electromagnetic signal.

[0014] The base layer is a polyimide film and / or a polyester film.

[0015] The thickness of the base layer is less than 200um.

[0016] The thermal control protection layer faces the external environment.

[0017] The satellite thermal control film with energy selection characteristics is used in spacecraft to achieve low-loss transmission of business signals, thermal control and strong electromagnetic protection functions.

[0018] Compared with the prior art, the present invention has the following technical effects:

[0019] (I) The present invention proposes that the energy selective layer attached to the substrate layer adopts a periodic structure of a diode. On the one hand, it can emit the solar spectrum and receive the solar absorption rate of the satellite thermal control film with energy selective characteristics, thereby improving the thermal control performance. On the other hand, the energy selective layer can change its own surface impedance characteristics according to the strength of the incident electromagnetic signal, thereby changing the surface impedance characteristics of the satellite thermal control film with energy selective characteristics, thereby achieving the protection capability of the strong electromagnetic environment in space with low loss transmission of weak electromagnetic signals and suppression of transmission of strong electromagnetic signals, thereby solving the shortcomings of the existing satellite thermal control film technology.

[0020] (II) The satellite thermal control film with energy selection characteristics proposed by the present invention adopts a multi-layer composite structure for integration, which is convenient for low-cost processing and manufacturing.

[0021] (III) The satellite thermal control film with energy selection characteristics proposed by the present invention is suitable for space environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the structure of a thermal control film for satellites with energy selection characteristics.

[0023] Figure 2 Schematic diagram of the periodic structure of an energy selective layer.

[0024] Figure 3 This is a simulation result diagram of the electromagnetic signal transmission loss (IL) of different polarization services and the protection performance of strong electromagnetic environment (SE) in space for the thermal control film for satellites with energy selection characteristics.

[0025] Figure 4 Schematic diagram of the periodic structure of another energy selective layer.

[0026] Figure 5 Schematic diagram of the installation of thermal control film for satellites with energy selection characteristics.

[0027] The meanings of the numbers in the figure are: 1-thermal control protection layer, 2-base layer, 3-energy selection layer, 4-metal layer, 5-polyimide layer, 6-antenna.

[0028] The specific contents of the present invention are further described in detail below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0029] It should be noted that, unless otherwise specified, all components and materials in the present invention are components and materials known in the prior art.

[0030] In accordance with the above technical scheme, specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical scheme of this application fall within the protection scope of the present invention.

[0031] Example:

[0032] This embodiment provides a satellite thermal control film with energy selection characteristics, such as Figure 1As shown, the thermal control film for satellites with energy selection characteristics is a multi-layer composite structure, which includes a thermal control protection layer 1, a base layer 2 and an energy selection layer 3. The thermal control protection layer 1 is bonded to one side of the base layer 2, and the other side of the base layer 2 is bonded to the energy selection layer 3; the thermal control protection layer 1, the base layer 2 and the energy selection layer 3 are all thin film structures.

[0033] like Figure 1 As shown, the thermal control protection layer 1 is composed of a metal layer 4 and a polyimide layer 5 , and the metal layer 4 is bonded to one side of the base layer 2 .

[0034] Specifically in this embodiment, the thermal control protection layer 1 faces the external environment, and the thermal control protection layer 1 is deposited on the surface of the base layer 2 by vacuum coating, magnetron sputtering, vacuum thermal evaporation or electron beam evaporation. The germanium film or doped germanium film is deposited.

[0035] Specifically in this embodiment, the material of the metal layer 4 in the thermal control protection layer 1 is germanium or doped germanium, and the thickness of the metal layer 4 is 100nm-10um; the thickness of the polyimide layer 5 is 10um-150um.

[0036] Preferably, in this embodiment, the thickness of the polyimide layer 5 in the thermal control protection layer 1 is 50 um.

[0037] Preferably, in this embodiment, the thickness of the metal layer 4 in the thermal control protection layer 1 is 2 um.

[0038] Specifically in this embodiment, the solar absorption ratio of the satellite thermal control film with energy selective characteristics is not greater than 0.45.

[0039] Specifically in this embodiment, the base layer 2 is a polyimide film and / or a polyester film.

[0040] Specifically in this embodiment, the thickness of the base layer 2 is less than 200 um.

[0041] In this embodiment, preferably, the number average molecular weight of the polyimide is 30,000.

[0042] In this embodiment, preferably, the polyester is polyethylene terephthalate, and the number average molecular weight of the polyester is 25,000.

[0043] In this embodiment, preferably, the material of the base layer 2 is polyimide and has a thickness of 100 um.

[0044] Specifically in this embodiment, the energy selection layer 3 uses a diode to adjust the surface impedance characteristics of the energy selection layer 3 .

[0045] Specifically in this embodiment, the periodic structure of the energy selection layer 3 is one or a combination of more than one of a cross structure, an annular gap, a cross gap and a straight structure.

[0046] Specifically in this embodiment, the interval of the periodic structure of the energy selection layer 3 is less than half the wavelength of the service electromagnetic signal.

[0047] Specifically in this embodiment, the energy selection layer 3 is made of a periodic structure composed of metal materials such as silver, gold, aluminum and copper; the energy selection layer 3 has high reflectivity in the solar spectrum band, and the energy selection layer 3 is used to achieve strong electromagnetic environment protection and signal transmission for normal business.

[0048] Specifically in this embodiment, the energy selection layer 3 uses a diode to regulate the surface impedance characteristics of the energy selection layer 3. When the electromagnetic signal intensity is less than 100V / m, the diode is disconnected, and the signal is transmitted through the energy selection layer 3 with low loss, and the transmission loss is less than 1dB; when affected by a strong electromagnetic environment, the diode is turned on, the surface impedance of the energy selection layer 3 changes, and the impedance of the surface of the satellite thermal control film with energy selection characteristics also changes, reflecting strong electromagnetic signals, and protecting the onboard electronic system from interference or damage by strong electromagnetic signals.

[0049] Specifically in this embodiment, the energy selection layer 3 uses or does not use the diode and the metal periodic structure processed on the same wafer, thereby reducing the parasitic parameters caused by packaging, improving the performance of the energy selection layer 3 and reducing the volume.

[0050] Specifically in this embodiment, the energy selection layer 3 is manufactured into a periodic structure with embedded diodes on the base layer 2 by using a PCB process or a semiconductor process.

[0051] In this embodiment, preferably, the diode of the energy selection layer 3 is a PIN diode or a Schottky diode.

[0052] In this embodiment, preferably, the energy selective layer 3 is formed by processing a diode and a metal periodic structure on the same wafer.

[0053] In this embodiment, preferably, the satellite thermal control film with energy selective characteristics is provided with through holes for releasing the gas that may be generated by the satellite thermal control film with energy selective characteristics in space applications.

[0054] In this embodiment, the periodic structure of the energy selection layer 3 is preferably as follows: Figure 2 As shown in Figure 1, the simulation results of electromagnetic signal transmission loss IL and space strong electromagnetic environment protection performance SE of different polarization services of satellite thermal control films with energy selection characteristics are shown in Figure 1. Figure 3 As shown. Figure 3It can be seen that when the center frequency is 2.85GHz, the bandwidth is 500MHz, and the electromagnetic signals of different polarization services are transmitted, the transmission loss IL of the satellite thermal control film with energy selection characteristics is less than 1dB. When the strong electromagnetic signal in space is incident on the satellite thermal control film with energy selection characteristics, the shielding effectiveness SE of the satellite thermal control film with energy selection characteristics is greater than 19dB, achieving good adaptive protection.

[0055] In this embodiment, another periodic structure of the energy selective layer 3 is preferably as follows: Figure 4 shown.

[0056] In this embodiment, the schematic diagram of the installation of the satellite thermal control film with energy selection characteristics is as follows: Figure 5 shown.

[0057] The satellite thermal control film with energy selection characteristics in this embodiment has a bandpass characteristic in the service signal frequency band, and is used in spacecraft to achieve low-loss transmission of service signals, thermal control and strong electromagnetic protection functions.

Claims

1. A satellite thermal control film with energy selective characteristics, characterized in that: The satellite thermal control film with energy selection characteristics is a multi-layer composite structure, which comprises a thermal control protective layer (1), a base layer (2) and an energy selection layer (3). The thermal control protective layer (1) is bonded to one side of the base layer (2), and the other side of the base layer (2) is bonded to the energy selection layer (3); the thermal control protective layer (1), the base layer (2) and the energy selection layer (3) are all thin film structures.

2. The satellite thermal control film with energy selective characteristics according to claim 1, characterized in that: The thermal control protection layer (1) is composed of a metal layer (4) and a polyimide layer (5). The metal layer (4) is made of germanium and has a thickness of 100nm to 10um; the polyimide layer (5) has a thickness of 10um to 150um.

3. The satellite thermal control film with energy selective characteristics according to claim 1, characterized in that: The solar absorption ratio of the satellite thermal control film with energy selection characteristics is not greater than 0.

45.

4. The satellite thermal control film with energy selective characteristics according to claim 1, characterized in that: The energy selection layer (3) uses a diode to regulate the surface impedance characteristics of the energy selection layer (3).

5. The satellite thermal control film with energy selective characteristics according to claim 1, characterized in that: The periodic structure of the energy selection layer (3) is one or a combination of more than one of a cross structure, an annular gap, a cross gap and a straight structure.

6. The satellite thermal control film with energy selective characteristics according to claim 1, characterized in that: The spacing of the periodic structure of the energy selection layer (3) is less than half the wavelength of the service electromagnetic signal.

7. The satellite thermal control film with energy selective characteristics according to claim 1, characterized in that: The base layer (2) is a polyimide film and / or a polyester film.

8. The satellite thermal control film with energy selective characteristics according to claim 1, characterized in that: The thickness of the base layer (2) is less than 200 um.

9. The satellite thermal control film with energy selective characteristics according to claim 1, characterized in that: The thermal control protection layer (1) faces the external environment.

10. The satellite thermal control film with energy selective characteristics according to any one of claims 1 to 9, characterized in that: The satellite thermal control film with energy selection characteristics is used in spacecraft to achieve low-loss transmission of business signals, thermal control and strong electromagnetic protection functions.

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