Lightweight monopole launch antenna for aerostat

Abstract

This invention discloses a lightweight monopole transmitting antenna for an aerostat. From the inside out, it comprises a central reinforcing filler made of multi-strand twisted lightweight reinforcing fibers, a binding layer made of polytetrafluoroethylene film, a non-metallic reinforcing layer woven from non-metallic reinforcing fibers, an inner sheath made of extruded polyethylene, a radiator layer woven from metal wires, and an outer sheath comprising a semi-conductive outer sheath and a metal-woven outer sheath. The semi-conductive and metal-woven outer sheaths have the same outer diameter and alternately cover the outside of the radiator layer. This invention offers advantages such as miniaturization, lightweight, corona resistance, high current resistance, and fatigue resistance, resulting in high reliability and practicality, meeting the requirements for rapid deployment of long-range very low frequency (VLF) communication systems using aerostats.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and in particular to a lightweight monopole transmitting antenna for an airship. Background Technology

[0002] Very low frequency (VLF) signals are electromagnetic waves with frequencies ranging from 3 kHz to 30 kHz and wavelengths from 10 km to 100 km. They propagate between the Earth's or ocean surface and the ionosphere, exhibiting characteristics such as ultra-long-distance propagation, low attenuation, stable communication, high data transmission rates, and strong penetration. They can be widely used in ocean-going communication, ground-penetrating communication, and geological exploration. In particular, submarines can utilize the ability of VLF signals to penetrate to depths of 5–15 meters in seawater, enabling underwater communication without surfacing. This effectively reduces the risk of detection and also shields them from the complex electromagnetic environment underwater, minimizing communication interference. Therefore, VLF communication has become the most effective means for command systems to achieve remote command and communication with submarines, significantly enhancing their communication and survivability.

[0003] Currently common long-distance VLF communication methods include shore-based VLF transmitting systems, airborne towed VLF transmitting systems, vehicle-mounted tethered balloon VLF transmitting systems, and spaceborne VLF transmitting systems. Among these, the vehicle-mounted tethered balloon VLF transmitting system is similar to the rapid deployment VLF communication system for aerostats used in this product; both involve launching an antenna from the ground, loading the signal on the ground, and transmitting it. However, a dedicated transmitting antenna for long-distance VLF communication using small aerostats has not yet been developed. Traditionally, long-distance VLF communication using aerostats is typically conducted using vehicle-mounted tethered balloon systems. However, the transmitting antennas used in vehicle-mounted tethered balloon VLF transmitting systems are heavy and have a large outer diameter, resulting in complex anchoring and deployment processes, high support requirements, and long preparation times, hindering rapid response. Therefore, there is an urgent need for a rapidly deployable transmitting antenna suitable for small aerostats. Summary of the Invention

[0004] To achieve the above objectives, the present invention provides a lightweight monopole transmitting antenna for an airship, comprising, from the inside out:

[0005] The central reinforcing filler is made of multiple strands of twisted lightweight reinforcing fibers;

[0006] A wrapping tape binding layer, wherein the wrapping tape binding layer is made of polytetrafluoroethylene film;

[0007] A non-metallic reinforcement layer, wherein the non-metallic reinforcement layer is woven from non-metallic reinforcing fibers;

[0008] Inner protective layer, wherein the inner protective layer is extruded from polyethylene material;

[0009] A radiator layer, wherein the radiator layer is woven from metal wires;

[0010] The outer sheath includes a semiconductor outer sheath and a metal braided outer sheath, wherein the semiconductor outer sheath and the metal braided outer sheath have the same outer diameter and alternately cover the outside of the radiator layer.

[0011] Furthermore, the central reinforcing filler is made of lightweight reinforcing fibers with a low dielectric loss tangent, which are twisted together.

[0012] Furthermore, the non-metallic reinforcing layer is made of aramid fiber.

[0013] Furthermore, the semi-conductive outer sheath is made of semi-conductive polyolefin material; the metal braided outer sheath is made of metal wire braiding.

[0014] Compared with existing technologies, the advantages of this invention are as follows: The lightweight monopole transmitting antenna for aerostats designed in this invention uses low-density lightweight reinforcing fiber material for the central reinforcing filler, which reduces the weight of the entire cable. The non-metallic reinforcing layer is made by weaving, which can provide tensile strength while achieving torque balance. All non-conductive materials are selected with low dielectric loss and tangent characteristics, which can effectively avoid excessive temperature rise caused by excessive dielectric loss from high-voltage very low-frequency signals during operation. Simultaneously, during the production process, based on the current distribution characteristics during antenna operation, the radiator is woven with metal wires of different cross-sectional areas in different sections to ensure that the overall weight of the antenna is reduced while controlling the temperature rise caused by current. The outer sheath includes a semi-conductive outer sheath and a metal braided outer sheath, which not only protect internal components, homogenize the electric field to prevent corona discharge, and effectively increase the antenna's outer diameter to improve radiation efficiency, but also allow adjustment of the length of the radiating segment during operation to match the wavelength of the transmitted signal. This invention has the advantages of miniaturization, lightweight, corona prevention, high current resistance, and fatigue resistance, making the product highly reliable and practical, and meeting the requirements for the rapid deployment of long-range very low frequency communication systems using airships. Attached Figure Description

[0015] Figure 1 This is a radial cross-sectional view of the lightweight monopole transmitting antenna for an airship according to the present invention;

[0016] Figure 2 This is an axial cross-sectional view of the lightweight monopole transmitting antenna for the airship of the present invention;

[0017] in,

[0018] 1-Central reinforcing filler, 2-Bag binding layer, 3-Non-metallic reinforcing layer, 4-Inner protective layer, 5-Radiator layer, 6-Outer protective layer, 61-Semi-conductive outer protective layer, 62-Metal braided outer protective layer. Detailed Implementation

[0019] The following description, with reference to the accompanying drawings, is provided to facilitate understanding of the technical solutions of the present invention by those skilled in the art. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention.

[0020] In the following detailed description, numerous specific details are set forth for ease of explanation to provide a full understanding of embodiments of the invention. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the invention.

[0021] Please see Figure 1-2 Figures show radial and axial sectional views of the lightweight monopole transmitting antenna for an airship according to the present invention. The lightweight monopole transmitting antenna for an airship is characterized by comprising, from the inside out:

[0022] The central reinforcing filler 1 is made of multi-strand twisted lightweight reinforcing fibers. The use of lightweight reinforcing fibers with low dielectric loss tangent characteristics provides sufficient support to prevent deformation and increases tensile strength. It also exhibits low dielectric loss under very low frequency, high voltage signals, preventing excessive temperature rise due to dielectric loss. The wrapping binding layer 2 is made of polytetrafluoroethylene film, which also has low dielectric loss tangent characteristics. It tightly binds the internal fibers while preventing temperature rise caused by dielectric loss. The non-metallic reinforcing layer 3 is woven from non-metallic reinforcing fibers. Pre-twisting effectively improves tensile strength, and the weaving method provides strength while meeting torque balance requirements, preventing cable self-twisting under tension. In some embodiments, the non-metallic reinforcing layer 3 is made of aramid fiber. The inner sheath 4 is made of extruded polyethylene material. Using natural-colored polyethylene, it binds the internal components and also features a low dielectric loss tangent, effectively reducing heat generation caused by dielectric loss from very low frequency high-voltage signals. It also serves as an isolation layer between the radiator and other internal components. The radiator layer 5 is made of multi-strand woven metal wires. Based on the antenna current distribution characteristics, the cross-sectional area of ​​the radiator is altered by increasing or decreasing the number of strands, controlling temperature rise while transmitting high-voltage signals and effectively reducing the overall weight of the antenna. The outer sheath 6 includes a semi-conductive outer sheath 61 and a metal braided outer sheath 62. The semi-conductive outer sheath 61 and the metal braided outer sheath 62 have the same outer diameter and alternately cover the outside of the radiator layer 5. The semi-conductive outer sheath is made of a polyolefin material with a certain degree of conductivity, effectively contacting the internal copper wire. This protects the internal components and improves the product's environmental adaptability. It also homogenizes the electric field, preventing the radiator from breaking off and generating corona discharge. Simultaneously, it effectively increases the antenna's outer diameter, thus improving radiation efficiency to some extent. The metal braided outer sheath 62 has the same outer diameter as the semi-conductive outer sheath, facilitating its deployment and retraction together. During operation, the metal wire outer sheath sections are wound around the wire storage drum and make contact with each other for conductivity. Its function is to adjust the length of the radiating section; the metal braided outer sheath 62 can be appropriately extended to adjust the radiating section, making it more compatible with the wavelength of the transmitted signal.

[0023] In summary, the lightweight monopole transmitting antenna for aerostats designed in this invention is applied to a rapid deployment VLF communication system using aerostats. During system operation, the aerostat propels the antenna upwards from the ground-based cable reeling equipment, thus erecting the antenna and maintaining it in a vertical, hovering state. At this point, the VLF signal is fed to the bottom of the antenna via a feeder on the ground and then transmitted for long-distance communication.

[0024] The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A lightweight monopole transmitting antenna for an airship, characterized in that, From the inside out, the following are included: The central reinforcing filler (1) is made of multiple strands of twisted lightweight reinforcing fibers; The wrapping binding layer (2) is made of polytetrafluoroethylene film; A non-metallic reinforcing layer (3) is made of non-metallic reinforcing fibers; Inner protective layer (4), wherein the inner protective layer (4) is made of polyethylene material by extrusion; The radiator layer (5) is made of woven metal wires; The outer sheath (6) includes a semi-conductive outer sheath (61) and a metal braided outer sheath (62). The semi-conductive outer sheath (61) and the metal braided outer sheath (62) have the same outer diameter and alternately cover the outside of the radiator layer (5).

2. The lightweight monopole transmitting antenna for an airship according to claim 1, characterized in that, The central reinforcing filler (1) is made of lightweight reinforcing fibers with a low dielectric loss tangent, which are twisted together.

3. The lightweight monopole transmitting antenna for an airship according to claim 2, characterized in that, The non-metallic reinforcing layer (3) is made of aramid fiber.

4. The lightweight monopole transmitting antenna for an airship according to claim 3, characterized in that, The semi-conductive outer sheath (61) is made of semi-conductive polyolefin material; the metal braided outer sheath (62) is made of metal wire braid.

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