RU168639U1 - High-weight thermally stable microwave waveguide - Google Patents

Abstract

The utility model relates to hollow microwave waveguides, and more particularly to their structures made of polymer composite materials with high weight efficiency and thermal stability for use in rocket and space technology, microwave waveguides with high weight efficiency and thermal stability, as a power-bearing material for the construction of a polymer composite waveguide the material is carbon fiber with a fiber reinforcement structure {0 ° / + 45 ° / -45 ° / 90 °}. Moreover, the orientation angles of the reinforcing in carbon fiber are given relative to the direction of the longest waveguide surface of the waveguide, and the metal coating of the waveguide hole is made of metal foil with a thickness of at least 50 μm, lined and molded to the inner surface of the power bearing material of the waveguide design during its manufacture, namely : on a rigid surface of the forming tooling, covered with release release agent, a layer of metal foil with cleaned and degreased surfaces is formed, then the above carbon reinforcing material is wound or laid out, then the binder is impregnated and cured, after which the finished waveguide with foil molded in the waveguide hole is removed from the snap-in. Reliable fastening of the metal foil to the inner surface of the carbon fiber waveguide is ensured by the adhesion of a binder used in carbon fiber, which acts as an adhesive joint with respect to the metal foil. Stability of geometric dimensions and shape

Description

Technical field

The utility model relates to hollow microwave waveguides, and more particularly to their structures made of polymer composite materials with high weight efficiency and thermal stability for use in space rocket technology.

State of the art

The waveguide microwave signal transmission lines are widely used in modern telecommunication systems: radio and television, guidance and location systems, communication devices, navigation systems, echo sounders and measuring equipment. High requirements imposed by the development of rocket-space and special equipment products predetermine the need to improve the target operational and functional characteristics of waveguides.

Traditional microwave transmission lines are known, made in accordance with GOST 18238-72 and made of waveguide copper or brass tubes of rectangular cross-section in accordance with GOST 20900-75, their nomenclature corresponds to the nomenclature of the International Electrotechnical Commission (IEC), as well as standards adopted in the USA - Energy Information Administration (EIA).

Known microwave waveguides using polymer composite materials for use in rocket and space technology in open space and described in the following patents.

“Antenna-feeder microwave device made of carbon composite material and method of its manufacture” (RF patent RU 2577918, IPC H01B 3/00, H01P 11/00, published: 03/20/2016) describes a waveguide element made entirely of graphene-containing carbon composite material with high electrical conductivity. In this case, the carbon fibers are located in a plane perpendicular to the axis of the waveguide element. The required number of layers of carbon composite yarn or fabric is wound onto the inner part of the blank of the waveguide element of the microwave device. Subsequently, the outer part of the matrix preform is put on the prepared product and, as a result of heating by vacuum molding, the surface roughness is eliminated. The external and internal matrices are separated and a waveguide element is obtained. The technical result is an increase in strength, a decrease in weight and size characteristics, a simplification of the manufacturing procedure. A characteristic feature of the inventive microwave device is the material from which it is made, having high electrical conductivity. It may have anisotropic conductivity, which allows you to vary the parameters of the device.

The main disadvantage of the waveguide described in patent RU 2577918 is that it does not have the property of thermal stability.

The invention "METAL PLATED BODY COMPOSED OF GRAPHITE FIBER EPOXY COMPOSITE" (US patent US 3982215, IPC H01P 1/208; H01P 1/20; H01P 3/12; H01P 11/00, published: 1976-09-21) can be considered more a close analogue of the proposed utility model. The patent describes a carbon fiber waveguide with an epoxy binder and electrically conductive thin metal layers on the body surfaces (structural material) of the waveguide: a thinner nickel scraper and a thicker copper layer on top of the nickel layer (there may also be a silver layer and a gold layer on top of the copper layer silver). The waveguide is made of carbon fiber, then smooth surfaces (internal and external) of the carbon fiber waveguide are given a slight roughness, and then metal conductive layers of nickel and copper are successively applied to these rough surfaces by electrochemical methods.

A disadvantage of the waveguide described in US Pat. No. 3,982,215 is the complexity of the multilayer metal coating of the carbon fiber body of the waveguide and its manufacturing technology and the strong dependence of the characteristics of the final device on the modes of technology and production level. In addition, this waveguide is not thermally stable.

The invention "FIBER REINFORCED PLASTIC COMPOUND AND WAVEGUIDE AND SEAT PLATE FOR TRAVELING WAVE TUBE USING SAID COMPOUND" (Japanese patent JPS 6062703, IPC H01J 23/12; H01P 11/00; H01P 3/12, published 1985-04-10) can be considered prototype of the proposed utility model. This patent describes a waveguide with increased weight efficiency and durability, the structural material of which is made of a three-layer fiber-reinforced (fibrous) polymer composite material (including fiber-reinforced fiberglass and a mixture of this fiberglass with graphite (carbon) fibers and aramid fibers of various variable lengths) with adjustable gradient change of linear thermal expansion coefficients (CTE), and CTE of the inner layer is almost equal to CTE film conductive metal coating in order to avoid delamination of the waveguide and metal coating layers and its cracking from the effects of extreme temperature extremes in outer space. As a conductive material of the waveguide hole, a thin-layer (10–20 μm thick) metal coating of predominantly copper (or aluminum or silver) is used, deposited in the waveguide hole by the vapor-phase metal transfer method or by galvanic electrolysis. Similar features of the prototype invention (patent JPS 6062703) with the proposed utility model consist in using the construction of a fibrous polymer composite material as a power material, as well as using a thin-layer metal coating as an electrically conductive material of the wave-conducting hole.

However, to prevent delamination of materials due to various temperature strains, the prototype used a multilayer material with a gradient in thickness of the CTE, and the CTE of the inner layer is almost equal to the CTE of the film conductive metal coating. Moreover, the prototype waveguide is quite complex in design (multilayer) and manufacturing technology and does not possess the property of thermal stability.

Utility Model Disclosure

The main difference between the proposed utility model and the above analogues and prototype is the creation of a thermally stable waveguide (CFLR of carbon fiber no more than 1⋅10 ^-6 K ^-1 )), which is achieved by using carbon fiber with an optimized, well-defined angular reinforcement structure; the creation of the electrically conductive surface of the waveguide hole is achieved by using a standard (guest) metal foil made of electrical alloys, reliably connected to the inner surface of the waveguide hole by molding the foil to the inner surface of the waveguide during its manufacture: lay out layer-by-layer on a rigid surface of the forming tooling, coated with release agent foil, then - uncured carbon fiber, then production The curing and waveguide are removed from the mandrel. The optimization of the structure of carbon fiber reinforcement to ensure thermal stability of the waveguide, according to the authors, leads to the practical absence of the influence of complex and variable thermal deformations that occur in open space on the electrical characteristics of the waveguide.

Moreover, the advantage of the proposed utility model lies in the simplicity of the design and the technology of its manufacture, which does not require many technological operations for electrochemical coating. In addition, the use of a typical element - a standard (guest) metal electrical foil provides stable high-quality electrical characteristics of the waveguide.

Thus, the technical result of the utility model is the creation of a waveguide with high weight efficiency, with geometrical dimensions (thermally stable waveguide) stable in a wide range of operating temperatures and stable electrical characteristics.

The technical result is achieved through the use of a polymer composite material — carbon fiber with a fiber reinforcement structure of {0 ° / + 45 ° / -45 ° / 90 °} in a microwave waveguide with high weight efficiency and thermal stability, as a force-bearing material — the angles the orientations of the reinforcing in carbon fiber are given relative to the direction of the longest waveguide surface of the waveguide, and the metal coating of the waveguide hole is made of a metal electrofoil purpose with a thickness of not less than 50 μm, lined and molded to the inner surface of the power bearing material of the waveguide structure during its manufacture, namely: on a rigid surface of the forming tooling, covered with release adhesive release composition, lay a layer of metal foil with cleaned and degreased surfaces, then the above carbon reinforcing material is wound or laid out, then the binder is impregnated and cured, after which the finished waveguide with Olga, integrally formed in the waveguide aperture, is removed from the molding tooling.

As a reinforcing carbon material, it is possible to use any continuous oriented carbon fillers that provide the necessary rigidity and strength of the material and structure: carbon filaments, tapes or fabrics. For example, it is possible to use carbon fibers of the brands Torayca, Toho Tenax or fibers of Russian manufacture of the UKN brand. The use of epoxy compound of the ЭХД-МД grade or any other type of binder, providing high physicomechanical characteristics of carbon fiber in a wide range of operating temperatures, is provided as a binder material. The thickness of the carbon fiber walls of the waveguide varies from 1.0 to 3.5 mm in accordance with the size of the waveguide.

The metal foil provides the target values of the electrical characteristics of the conductive skin layer, the isotropy and uniformity of these characteristics, namely: electrical resistivity less than 0.03 (Ohm × mm ² ) / m; relative magnetic permeability of 1.06 or less. As the material of the used foil, standard electrotechnical alloys of aluminum, copper, silver, and gold can be used, for example, СРМ925 0.05 × 125 P foil according to GOST 24552-2014.

Reliable fastening of the metal foil to the inner surface of the carbon fiber waveguide is ensured by the adhesion of a binder used in carbon fiber, which acts as an adhesive joint with respect to the metal foil.

The stability of the geometric dimensions and shape of the conductive surface formed by the metal foil is ensured by an external rigid and durable thermally stable casing made of carbon fiber. The joint work of carbon fiber and foil is ensured by a reliable adhesive bond formed between the formed foil and carbon fiber in the process of impregnation and curing of the binder. So, with significant changes in temperature, the thermosize-stable carbon fiber retains the shape and dimensions of the waveguide and the conductive surface of the foil, i.e. the stress state of carbon fiber can vary with the practical geometrical dimensions and shape of the shell and foil, which is the key to thermal stability of the entire waveguide.

List of figures

The essence of the claimed device is illustrated by graphic materials:

FIG. 1 - design of a thermally stable microwave waveguide with high weight efficiency;

FIG. 2. - calculated dependences of the longitudinal and transverse KLTR carbon fiber versus the angle of mutual orientation of the reinforcing fibers;

FIG. 3 is a general view and overall dimensions of a sample of a heat-stable microwave waveguide with high weight efficiency for a space-size stable antenna;

FIG. 4 - general view and dimensions of a spatial composite structure (space dimensionally stable antenna) with high weight efficiency and thermal stability for rocket and space technology;

FIG. 5 is an enlarged image of the attachment site and a signal transmission line as part of a spatial composite structure with high weight efficiency and thermal stability for rocket and space technology.

Utility Model Implementation

The creation of composite structures (including the proposed waveguide) with high weight efficiency and thermal stability can be realized, for example, through the use of technology (method) of dry weaving, or winding, or laying out together with RTM (VARTM) impregnation technology (method), or other technologies (methods) of molding products from polymer composite materials providing the required quality: temperature range of working capacity from minus 150 ° C to plus 120 ° C; reduction of physical and mechanical characteristics at a temperature of plus 120 ° C no more than 20%; the ability to operate the finished product in a space vacuum.

In FIG. 1 shows the design of a thermally stable microwave waveguide with high weight efficiency, made of thermally stable carbon fiber with a conductive coating of a waveguide hole made of metal electrical foil. In addition to the waveguide path (waveguide), a connecting flange is also shown, the shape and dimensions of which are also typical and are determined by the dimensions of the waveguide. Typical dimensions of waveguide connecting flanges are given in the nomenclature of waveguides by the International Electrotechnical Commission (IEC), as well as the standards adopted in the USA - Energy Information Administration (EIA). The specific design of the connecting flange may be different, but in the case of heat-stable carbon fiber waveguide, the flange can be made as a single integral product with a wave-conducting path, or as a separate product, forming a detachable connection with the wave-conducting path.

A thermo-dimensionally stable microwave waveguide with high weight efficiency is a waveguide made of a polymer composite material - carbon fiber reinforced with a reinforcing structure {0 ° / + 45 ° / -45 ° / 90 °}, which ensures thermal dimensional stability of the material and the waveguide design, as well as weight efficiency. This reinforcement structure is determined as a result of calculating the thermal expansion coefficients of the composite material of the waveguide model with varying laying angles of the reinforcing filler. An illustration of the results of this calculation is shown in FIG. 2, where it is clearly seen that it is precisely at the angle of mutual orientation of the reinforcing that is equal to 45 ° that the longitudinal and transverse CTE of the carbon fiber reinforced plastic are simultaneously close to zero (see the intersection point of both CTE diagrams).

A thermo-dimensionally stable microwave waveguide with high weight efficiency has standard geometric dimensions and shapes provided for by the standard range of sizes: GOST 20900-75, the range of the International Electrotechnical Commission (IEC), and also the standards adopted in the USA - Energy Information Administration (EIA).

The inner waveguide surface of the carbon fiber waveguide is lined with metal foil for electrical purposes, which provides the target values of the electrical characteristics of the conductive skin layer, the isotropy and uniformity of these characteristics, namely: specific electrical resistance less than 0.03 (Ohm × mm ² ) / m; relative magnetic permeability of 1.06 or less. The thickness of the used foil should be at least 50 microns, which ensures the manufacturability of its use in the manufacture of the waveguide. The foil is molded to the inner surface of the waveguide during its manufacture: a layer of metal foil with cleaned and degreased surfaces is laid on the rigid surface of the forming tooling, covered with release adhesive, then carbon reinforcing material is wound or laid out, then the binder is impregnated and cured, and then finished the waveguide with the molded foil is removed from the snap. As the material of the foil used, standard electrotechnical alloys of aluminum, copper, silver, gold and other metals can be used. Reliable fastening of the metal foil to the inner surface of the carbon fiber waveguide is ensured by the adhesion of a binder used in carbon fiber, which acts as an adhesive joint with respect to the metal foil. Standard electrotechnical alloys of aluminum, copper, silver, gold and other metals can be used as the material of the used foil, for example, the use of СРМ925 0.05 × 125 P foil according to GOST 24552-2014. The stability of the geometric dimensions and shape of the conductive surface formed by the metal foil is ensured by an external rigid and durable thermally stable surface-shell made of carbon fiber. The joint work of carbon fiber and foil is ensured by means of an adhesive joint formed between the foil and carbon fiber in the process of impregnation and curing of the binder. So, when temperatures change, carbon fiber retains the shape and dimensions of the waveguide and the conductive surface of the foil, i.e. the stress state of carbon fiber can vary while maintaining the geometric dimensions and shape of the waveguide, which is the key to thermal stability.

Utility Model Example

A model of the utility model device (thermally stable microwave waveguide with high weight efficiency) was made and used in the design and creation of spatial composite structures with high weight efficiency and thermal stability for rocket and space technology, as part of the work on the Agreement on the provision of subsidy No. 14.577.21.0130 of 28 October 2014 with the Ministry of Education and Science of the Russian Federation. Unique identifier of applied research (project) RFMEFI57714X0130.

A general view of the thermally stable microwave waveguide with high weight efficiency is shown in FIG. 3. Its overall dimensions are as follows: a = 7.1 ± 0.05 mm; b = 3.6 ± 0.05 mm; S = 1.1 ± 0.15 mm; A = B = 27.5 ± 0.5 mm; D = 13.0 ± 0.5 mm, L = 36 ± 1.0 mm. The waveguide has the following operational characteristics: recommended operating frequency range from 26.50 GHz to 40.00 GHz; cutoff frequencies of operation from 21.07 GHz to 42.15 GHz; with the following dimensions of the waveguide hole: width a = 7.1 ± 0.05 mm; height b = 3.6 ± 0.05 mm, which is ensured by polishing "in size". Carbon fiber based on reinforcing M46 Torayca and a binder ЭХД-МД was used as a material of the power forming structure of the waveguide.

The structural formula of the specified laminitis is: {0 ° / + 45 ° / -45 ° / 90 °}, this structure of the carbon-plastic laminate provides thermal stability of the waveguide design, which contributes to the stability of the target electrical characteristics of the waveguide. The use of carbon fiber with a density of 1500 ± 100 kg / m ³ as the body material of the waveguide provides a lightening of each meter of the waveguide by at least 5 times in comparison with traditional brass and copper waveguides, the material density of which lies in the range from 8500 to 8900 kg / m ³ . As a material of the waveguide hole of the waveguide, a CPM925 0.05 × 125 P foil was used in accordance with GOST 24552-2014. To reduce the loss factor of the waveguide before putting it into operation, it is necessary to polish the current-carrying surface of the foil with metal felt grinding (technical semi-coarse felt GOST 6308-71), which made it possible to achieve a surface roughness Ra of 0.03 μm.

An example of the specific use of this sample of a thermally stable microwave waveguide as part of a spatial composite structure with high weight efficiency and thermal stability for rocket and space technology is shown in FIG. 4 and FIG. 5. In FIG. 4 shows a general view and dimensions of a spatial composite structure with high weight efficiency and thermal stability for rocket and space technology, where 1 is a spatial composite structure; 2 - parabolic antenna reflector; 3 - an element of the power spatial truss intended for mounting the waveguide. In FIG. 5 shows an enlarged view of the attachment point and signal transmission line as part of a spatial composite structure with high weight efficiency and thermal stability for rocket and space technology: position 3 is an element of a power spatial truss designed to mount a waveguide; 4 - adapter plate-mount; 5 - transceiver device (Gunn diode); 6 - thermally stable microwave waveguide with high weight efficiency.

Claims (3)

1. Microwave waveguide with high weight efficiency and thermal stability, using as a power carrier material the structure of a polymer composite material — fiber reinforced carbon fiber and a thin layer conductive electrical material of the waveguide hole in the form of a thin layer metal coating, characterized in that the carbon fiber has a fiber reinforcement structure {0 ° / + 45 ° / -45 ° / 90 °}, and the angles of orientation of the reinforcing in carbon fiber are given relative to the direction of the longest of the waveguide surface of the waveguide, and the metal coating of the waveguide hole is made of metal foil of electrical purpose with a thickness of at least 50 μm, lined and molded to the inner surface of the power bearing material of the waveguide structure during its manufacture, namely, with the possibility of a rigid surface of the forming tooling covered with anti-adhesive release agent, spreading a layer of metal foil with cleaned and degreased surfaces, then yvaniya or vykladyvaniya aforementioned carbon reinforcing material further impregnation and curing of the binder, and then removing the finished waveguide foil integrally formed in the waveguide bore, with the forming tooling. 2. The microwave waveguide according to claim 1, characterized in that as a reinforcing carbon material, any continuous oriented carbon fillers can be used to provide the necessary rigidity and strength of the material and structure: carbon filaments, tapes or fabrics, mainly Torayca carbon fibers can be used , Toho Tenax or Russian-made UKN fibers; The use of epoxy compound of the ЭХД-МД grade or any other type of binder, providing high physicomechanical characteristics of carbon fiber in a wide range of operating temperatures, while the thickness of the carbon-plastic walls of the waveguide varies from 1.0 to 3.5 mm in accordance with the size of the waveguide. 3. The microwave waveguide according to claim 1, characterized in that the metal foil provides the target values of the electrical characteristics of the conductive skin layer, the isotropy and uniformity of these characteristics, namely: electrical resistivity less than 0.03 (Ohm × mm ² ) / m ; relative magnetic permeability of 1.06 or less, mainly the use of foil grade СРМ925 0,05 × 125 Р, also standard electrotechnical alloys of aluminum, copper, silver, gold can be used as the material of the used foil.

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