An inverted umbrella conformal antenna with deceleration and communication characteristics

Abstract

The application provides an inverted umbrella conformal antenna with deceleration and communication characteristics, which comprises a canopy, a feed source, a plurality of motion joint assemblies and a plurality of supporting skeletons; each supporting skeleton is in a vertical state with a circumferential surface formed by the plurality of motion joint assemblies, and is rotated to a horizontal direction by a pull rod under the action of elastic potential energy stored by a compression spring in the motion joint assembly hinged thereto, and simultaneously drives the canopy fixed between adjacent supporting skeletons to be unfolded into an inverted curved surface structure; the conductive supporting skeletons symmetrically distributed on the left and right sides of the antenna central axis can support the canopy and respectively serve as positive and negative oscillators of a symmetric array antenna. The application uses the conductive supporting skeletons of the umbrella surface to form a symmetric array antenna, avoids the defect that the antenna performance is affected by the winding of the umbrella rope in the prior art, and simultaneously the antenna is omnidirectional radiation with a maximum radiation direction perpendicular to the ground, which is more conducive to ground-to-air communication.

Description

Technical Field

[0001] This invention belongs to the field of shortwave communication technology and relates to an inverted umbrella conformal antenna that combines deceleration and communication characteristics. It can be applied to long-distance communication where communication equipment cannot be established on the ground due to complex terrain or destroyed roads. Background Technology

[0002] With the development of technology in the field of communications, shortwave antennas have been widely used in various long-distance communications. They primarily rely on the establishment of communication equipment at both the transmitting and receiving ends. However, in emergencies such as disaster relief, complex terrain or destroyed roads may prevent the installation of communication equipment or damage, hindering timely understanding of the disaster area's situation. In such cases, to ensure the survival of people in the disaster area, airdropped supplies are often necessary. To prevent damage to supplies or injury to people on the ground due to excessive descent speed, airdrop containers are equipped with small wind deflectors, deceleration parachutes, and other slowing devices to effectively reduce the impact upon landing.

[0003] By integrating low-frequency communication antennas with deceleration parachutes using airdropped supplies as a carrier, a design that combines deceleration and ground communication can be achieved without increasing weight. For example, patent application CN109037973A, entitled "A Conformal Parachute Antenna," includes upper parachute lines and wires, lower parachute lines and wires, a feed, a canopy, and parachute lines without added wires. The bottom convergence point of the upper parachute lines and wires is fixedly connected to the inner core of the coaxial line at the top of the feed. The top and bottom of the lower parachute lines and wires converge at a single point, and the top convergence point is fixedly connected to the outer sheath of the coaxial line at the bottom of the feed. The lower parachute lines and wires have bending points, which are connected to the bottom end of each parachute line without added wires. Each parachute line without added wires is fixedly connected to the lower edge of the canopy at the top. This invention solves the problems of complex antenna structure and difficult storage of jammers. However, under the influence of external forces, the parachute ropes can cause the antenna wires to deform when wrapped, which in turn affects the antenna radiation performance. In addition, the maximum radiation direction of the antenna when it is placed vertically is horizontal, and the antenna will be subject to more vertically polarized industrial electromagnetic interference. At the same time, this invention requires the antenna and the object to be fixed by the parachute ropes, resulting in a large size of the antenna and parachute after deployment. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects of the prior art and propose an inverted umbrella conformal antenna that combines deceleration and communication characteristics. This solves the technical problems of poor antenna radiation performance and large size after deployment in the prior art, and is more conducive to ground-to-air communication.

[0005] To achieve the above objectives, the technical solution adopted by the present invention includes a canopy 1 and a feed source 2, and also includes multiple motion joint components 3 fixed on the delivery object and arranged at equal intervals in a circle, and a support frame 4 hinged to each motion joint component; the motion joint component 3 includes a compression spring 31 and a pull rod 35 for driving the support frame 4 to rotate from a vertically retracted state to a horizontal direction, and an electromagnetic valve 32 connected to the bottom end of the compression spring 31 for switching the support frame 4 to rotate from a vertical direction to a horizontal direction; some of the multiple support frames are conductive support frames, and the remaining support frames are non-conductive support frames, and the conductive support frames are symmetrically distributed on the left and right sides about the central axis of the antenna. The effective length l of the support frame 4 is determined by the radiation center frequency of the antenna f = c / 4l, where c is the speed of light; the canopy 1 is fixed between adjacent support frames 4; the feed source 2 is fixed on the axis of the spatial circle formed by the multiple motion joint components 3, and is connected to each conductive support frame through a metal wire 5.

[0006] When the item is deployed, each support frame is perpendicular to the circumferential surface formed by multiple motion joint components. Under the action of the elastic potential energy stored in the compressed spring in the motion joint components that are hinged to it, it rotates horizontally through the pull rod. At the same time, it causes the canopy fixed between adjacent support frames to unfold into an inverted curved structure. The conductive support frames symmetrically distributed on the left and right sides of the antenna's central axis can not only support the canopy, but also serve as the positive and negative pole elements of the symmetrical array antenna, respectively.

[0007] The antenna described above, specifically the canopy 1, is made of a high-strength, airtight material.

[0008] The aforementioned antenna, specifically the feed source 2, employs a coaxial feeding structure. Its inner and outer conductors are connected to the positive and negative poles of the antenna via metal wires 5, respectively, and are supplied with alternating current.

[0009] The aforementioned antenna, the motion joint assembly 3, further includes a slide 33 fixed to the object being placed, a slider 34 embedded in the slide 33, and a metal bracket 36 disposed at the lower end of the slide 33; the top end of the compression spring 31 is fixed to the upper end of the slide 33; the solenoid valve 32 is fixed between the bottom end of the compression spring 31 and the slider 34; one end of the pull rod 35 is connected to the slider 34 via a hinge 37, and the other end of the pull rod 35 is connected to a hinge 37 disposed on the support frame 4; the metal bracket 36 is used for movably connecting with the support frame 4.

[0010] The conductive support frame of the aforementioned antenna is constructed using a metal tubular structure.

[0011] The aforementioned antenna, specifically the conductive support frame, employs a non-metallic rod structure coated with a metallic conductive layer, which is used to connect with the metal wire 5.

[0012] The aforementioned antenna, specifically the conductive support frame, employs a non-metallic rod structure with metal wires wound around it, the metal wires being used to connect to the metal wire 5.

[0013] The aforementioned antenna, specifically the non-conductive support frame, employs a non-metallic tubular structure.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] 1. In this invention, multiple conductive support frames, under the action of the elastic potential energy stored in the compression spring, unfold from a state perpendicular to the circumferential surface formed by multiple moving joint components into a counter-array antenna structure. This avoids the influence of paracord entanglement on antenna radiation performance in existing technologies. Furthermore, it radiates the most in the direction perpendicular to the ground and is omnidirectional. This can avoid industrial electromagnetic interference caused by vertical polarization and achieve better diffraction capability than vertically polarized waves in complex terrain environments, thereby expanding the radiation coverage area.

[0016] 2. The multiple conductive support frames in this invention serve as the positive and negative pole elements of the array antenna, respectively. Even if mechanical deformation occurs due to wind resistance during the delivery of the item, the impact on the antenna's operating frequency band is minimal, thus providing a stable operating bandwidth.

[0017] 3. The multiple conductive support frames in this invention also serve as the positive and negative elements of the symmetrical array antenna, avoiding the defect of the large size of the antenna after unfolding caused by the existing technology which is composed of paracords and metal wires in the upper and lower parts. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention in its working state;

[0019] Figure 2 This is a schematic diagram of the overall structure of the invention in its non-working state;

[0020] Figure 3 This is a diagram showing the relationship between the motion joint assembly and the supporting frame of the present invention.

[0021] Figure 4 This is a simulation model diagram of the present invention;

[0022] Figure 5 This is a simulation diagram of the return loss S11 as a function of frequency according to the present invention.

[0023] Figure 6 This is a simulation diagram of the radiation direction of the present invention. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0025] Reference Figure 1 and Figure 2 The present invention includes a canopy 1, a feed source 2, six motion joint components 3 fixed on the delivery object and arranged at equal intervals around the circumference, and a support frame 4 hinged to each motion joint component.

[0026] The canopy 1 is fixed between adjacent support frames 4. The canopy 1 is made of high-strength airtight material. During the descent of the object, it unfolds with the rotation of the support frame 4 to form an inverted curved surface structure, which provides resistance to the object and slows it down.

[0027] The feed source 2 is fixed on the axis of the spatial circumference formed by the six motion joint components 3. The feed source 2 adopts a coaxial feeding structure, and its inner conductor and outer conductor are connected to the positive pole and negative pole of the antenna through metal wires 5 respectively, and provide them with alternating current.

[0028] The structure of the motion joint assembly 3 is as follows: Figure 3 As shown, the system includes a compression spring 31, a solenoid valve 32, a slide groove 33, a slider 34, a pull rod 35, a metal bracket 36, and a hinge 37. The top end of the compression spring 31 is fixed to the upper end of the slide groove 33, and the bottom end is connected to the solenoid valve 32. Before an item is placed, it is in a compressed state, storing elastic potential energy. One end of the pull rod 35 is connected to the slider 34 via the hinge 37, and the other end of the pull rod 35 is connected to the hinge 37 on the support frame 4. Driven by the elastic potential energy of the compression spring 31, it pushes the support frame 4 to rotate from a vertically retracted state to a horizontal state. The solenoid valve 32 is fixed between the bottom end of the compression spring 31 and the slider 34, used to switch the support frame 4 from a vertical to a horizontal direction. The slide groove 33 is fixed to the item being placed. The slider 34 is embedded in the slide groove 33. The metal bracket 36 is located at the lower end of the slide groove 33 and is used for movable connection with the support frame 4.

[0029] The supporting frame 4 has a length l calculated as 10m from the antenna's radiation center frequency f = c / 4l, and a radius of 0.01m. The antenna's radiation center frequency is 7.5MHz. Some of the supporting frames are conductive, while the remaining frames are non-conductive. The conductive supporting frames are non-metallic tubular structures coated with a conductive metal layer, and the non-conductive supporting frames are also non-metallic tubular structures. Before placing an item, each supporting frame is rotated and retracted to a vertical position via a motion joint assembly, at which point the supporting frame is parallel to the sliding groove in the motion joint assembly. When placing an item, the supporting frame rotates horizontally via a pull rod under the action of the elastic potential energy stored in the compression spring. The conductive supporting frame forms a symmetrical array antenna structure with the left and right sides of the central axis serving as positive and negative poles, respectively. The angle between the supporting frame and the antenna's central axis is α, and the horizontal projection angle between adjacent supporting frames is β. In this embodiment, α = 75° and β = 60°.

[0030] The conductive support frame also adopts a non-metallic rod structure with metal wires wound around it, or a metal tube structure. When the conductive support frame adopts a non-metallic tube structure coated with a metal conductive layer, the two ends of the metal wire 5 are respectively connected to the metal conductive layer and the inner and outer conductors of the feed source 2. When the conductive support frame adopts a non-metallic rod structure with metal wires wound around it, the two ends of the metal wire 5 are respectively connected to the metal wires and the inner and outer conductors of the feed source 2. When the conductive support frame adopts a metal tube structure, the two ends of the metal wire 5 are respectively connected to the body of the metal tube structure and the inner and outer conductors of the feed source 2.

[0031] The non-conductive support frame adopts a carbon fiber structure, and its bottom end is not connected to the metal wire 5.

[0032] The working principle of this invention is as follows: When the solenoid valve opens, the slider slides upwards along the groove under external force. The support frame, pulled by the rod connected to the slider, rotates around the metal bracket until it is parallel to the groove. Simultaneously, the compression spring stores energy under the upward thrust of the slider. When dropping items, the antenna structure is mounted on the dropped material and delivered to the designated point by the aircraft. During descent, the solenoid valve connected to the bottom of the compression spring opens after receiving an external control signal. The slider moves downwards under the elastic potential energy stored in the compression spring, driving the rod through the hinge. This causes the vertical support frame to rotate horizontally under the push of the rod. During this process, the solenoid valve prevents the support frame from moving back due to wind resistance. When the support frame rotates to an angle α with the center line of the excitation point... The solenoid valve receives a control signal again and closes, fixing itself to the slide groove via a slider, thus maintaining the stable shape of the support frame. The support frame can be either conductive or non-conductive, with conductive support frames symmetrically distributed on both sides of the antenna's central axis. These frames support the canopy and also serve as the positive and negative pole elements of the array antennas. Non-conductive support frames only support the canopy. The canopy, fixed between adjacent support frames, unfolds together with the support frames, providing resistance to the projected object for deceleration. Simultaneously, after the canopy unfolds, the shortwave antenna begins to operate, with internal excitation providing alternating current to the metal frame via a coaxial feeder. The conductive support frames distributed on the canopy, forming the array antennas, convert the alternating electrical signal into electromagnetic waves that radiate towards the ground.

[0033] The technical effects of this invention will be explained below with reference to simulation experiments:

[0034] 1. Simulation conditions and content:

[0035] A simulation model of the antenna was established using ANSYS Electronics Desktop software. The antenna's support frame is 10m long and has a radius of 0.01m. Four conductive support frames are made of copper-coated tubular structures with a conductivity of 5.8e7 S / m, and are symmetrically distributed on both sides of the antenna's central axis. Two non-conductive support frames are made of carbon fiber tubular structures. The relative permittivity of the umbrella material is 1. The antenna operates at a frequency of 7.5MHz, with a sweep bandwidth of 1-13MHz and a step size of 0.2. The Driven model solver was used for simulation analysis.

[0036] Simulations were performed on the return loss S11 of the present invention as a function of frequency and the radiation pattern, and the results are as follows: Figure 5 and Figure 6 As shown.

[0037] 2. Simulation Result Analysis:

[0038] Reference Figure 5 It can be seen that the antenna has good radiation characteristics in the 6.76-7.7MHz frequency band, that is, the antenna S11≤-10dB and the relative bandwidth is 13%.

[0039] Reference Figure 6 The solid and dashed lines in the figure represent the E and H plane radiation patterns of the antenna, respectively. It can be seen that the antenna has omnidirectional radiation characteristics in the vertical direction of the opened canopy. Its maximum radiation direction is perpendicular to the ground. Therefore, it can avoid vertical polarization industrial electromagnetic interference and has better diffraction capability in areas with complex terrain, thus covering a wider area.

Claims

1. An inverted umbrella conformal antenna with both deceleration and communication characteristics, comprising a canopy (1) and a feed (2), characterized in that, It also includes multiple motion joint components (3) fixed on the object and arranged at equal intervals in a circle, and a support frame (4) hinged to each motion joint component; the motion joint component (3) includes a compression spring (31) and a pull rod (35) for driving the support frame (4) to rotate from a vertically retracted state to a horizontal state, and a solenoid valve (32) connected to the bottom end of the compression spring (31) for switching the support frame (4) to rotate from a vertical direction to a horizontal direction; some of the multiple support frames are conductive support frames, and the remaining support frames are non-conductive support frames, and the conductive support frames are symmetrically distributed on the left and right sides about the central axis of the antenna, and the effective length of the support frame (4) is... The radiation center frequency of the antenna The decision, among which, The speed of light; the canopy (1) is fixed between adjacent support frames (4); the feed source (2) is fixed on the axis of the spatial circumference formed by multiple motion joint components (3) and connected to each conductive support frame through a metal wire (5); The motion joint assembly (3) further includes a slide groove (33) fixed to the object being placed and a slider (34) embedded in the slide groove (33), and a metal bracket (36) disposed at the lower end of the slide groove (33); the top end of the compression spring (31) is fixed to the upper end of the slide groove (33); the solenoid valve (32) is fixed between the bottom end of the compression spring (31) and the slider (34); one end of the pull rod (35) is connected to the slider (34) via a hinge (37), and the other end of the pull rod (35) is connected to a hinge (37) disposed on the support frame (4); the metal bracket (36) is used to movably connect with the support frame (4); When the item is deployed, each support frame is perpendicular to the circumferential surface formed by multiple motion joint components. Under the action of the elastic potential energy stored in the compressed spring in the motion joint components that are hinged to it, it rotates horizontally through the pull rod. At the same time, it causes the canopy fixed between adjacent support frames to unfold into an inverted curved structure. The conductive support frames symmetrically distributed on the left and right sides of the antenna's central axis can not only support the canopy, but also serve as the positive and negative pole elements of the symmetrical array antenna, respectively.

2. The antenna according to claim 1, characterized in that, The canopy (1) is made of high-strength, airtight material.

3. The antenna according to claim 1, characterized in that, The feed source (2) adopts a coaxial feeding structure, and its inner conductor and outer conductor are connected to the positive pole and negative pole of the antenna through metal wire (5) to provide them with alternating current.

4. The antenna according to claim 1, characterized in that, The conductive support frame is constructed using metal tubing.

5. The antenna according to claim 1, characterized in that, The conductive support frame adopts a non-metallic rod structure coated with a metal conductive layer, which is used to connect with the metal wire (5).

6. The antenna according to claim 1, characterized in that, The conductive support frame adopts a non-metallic rod structure with metal wires wound around it, and the metal wires are used to connect with the metal wires (5).

7. The antenna according to claim 1, characterized in that, The non-conductive support frame adopts a non-metallic tubular structure.

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