Ultra-wideband omnidirectional antenna conformal to helium balloon with biconical bottom feed

Abstract

The present invention discloses an ultra-wideband omnidirectional radiating antenna with a biconical bottom feed conforming to a helium balloon, belonging to the technical field of inflatable antennas, and comprising: an upper conductor radiating structure, a lower conductor feeding device, and an upper and lower conductor reinforcement device; the upper conductor radiating structure is a hollow conical patch, which can conform to the helium balloon and be connected to the inner conductor of the coaxial line; the lower conductor feeding device is a combination of a cylinder and a semicircle, using 3D printing technology, and a hollow design is adopted in the center. In order to enhance toughness, a layer of copper film is wrapped outside the 3D print and connected to the coaxial outer conductor. The upper and lower conductor reinforcement devices are on the outer layer of the upper and lower conductors, and are a bidirectional sleeve structure that sleeves the upper and lower conductors, and are connected to the upper and lower conductors with studs, so that the upper and lower conductors become a whole. The present invention has ultra-wideband characteristics, a frequency band range of 200MHz-425MHz, an omnidirectional characteristic of the directional pattern, an in-band gain greater than 2.4dB, and a maximum of 3.6dB. The antenna can be raised to a height of more than 30 meters to work stably.

Description

Technical Field

[0001] The present invention belongs to the technical field of inflatable antennas, and more specifically, relates to an ultra-wideband omnidirectional radiating antenna with a biconical bottom feed that can conform to a helium balloon. The antenna lifting operation is completed by controlling the helium balloon, and the antenna can be used as a temporary relay means for long-distance and rapid transmission between offshore and land platforms. Background Art

[0002] With the rapid development of wireless communication technology, various types of electromagnetic interference are affecting people's lives everywhere. There are complex electromagnetic signals in cities, suburbs and other environments. In addition, due to the limitation of the earth's curvature radius and the influence of buildings on the ground, how to ensure stable and reliable transmission capabilities and strong electromagnetic anti-interference characteristics in complex electromagnetic interference environments during long-distance and fast transmission has put forward new requirements for antenna design.

[0003] Ultra-wideband antennas have the advantages of improving channel capacity, good anti-interference ability, and can achieve rapid signal transmission, becoming a favorable carrier for long-distance transmission and electromagnetic anti-interference. In order to overcome the influence of the earth's curvature radius and ground buildings, the antenna can be raised. This method is similar to the traditional base station using a steel frame structure to increase the height of the antenna from the ground to avoid interference from the earth's curvature radius and near-surface buildings. The traditional steel frame structure is used to raise the antenna, but the height from the ground is extremely limited. It will still be affected by the earth's curvature radius during ultra-long-distance transmission, and cannot solve the problems caused by ultra-long-distance transmission. In addition, the steel frame elevation method is only suitable for long-term fixed-point use, which is extremely inconvenient for temporary use during wartime. Summary of the invention

[0004] In view of the above defects or improvement needs of the prior art, the present invention proposes a bi-conical bottom-fed ultra-wideband omnidirectional radiating antenna that is conformal to a helium balloon, which solves the problem that the existing antenna cannot work stably and reliably during long-distance rapid transmission due to the influence of the earth's curvature radius and ground buildings.

[0005] To achieve the above object, the present invention provides a biconical bottom-fed ultra-wideband omnidirectional radiating antenna conformal to a helium balloon, comprising: an upper conductor radiating structure, a lower conductor feeding device, and upper and lower conductor reinforcement devices, wherein the upper conductor radiating structure is connected to the lower conductor feeding device through the upper and lower conductor reinforcement devices;

[0006] The upper conductor radiation structure is a hollow conical patch, conforming to the helium balloon and connected to the inner conductor of the coaxial line;

[0007] The lower conductor feeding device is a combination of a cylinder and a semicircle, with a hollow center, connected to the outer conductor of the coaxial line;

[0008] The upper and lower conductor reinforcement devices are bidirectional sleeve structures that respectively sleeve the upper conductor radiation structure and the lower conductor feeding device, and are connected to the upper conductor radiation structure and the lower conductor feeding device with studs, so that the upper conductor radiation structure and the lower conductor feeding device become a whole.

[0009] In some optional embodiments, a plurality of No. A cables are symmetrically fixed on the central axis of the helium balloon; and a plurality of No. B cables are partially fixed to the lower conductor feeding device symmetrically around the central axis of the helium balloon.

[0010] In some optional embodiments, a C-cable is used to bond and fix a load-bearing steel wire rope to the cable, and the weight borne by the cable is transferred to the steel wire rope to produce a composite cable for protecting the radio frequency cable.

[0011] In some optional implementation schemes, an inflation and deflation pump is provided on the helium balloon, and the inflation and deflation pump completes the inflation and deflation operation of the inflation and deflation pump by sending and receiving signals through the F line.

[0012] In some optional implementation schemes, in the working mode of ground inflation and air deflation, the inflation and deflation pump is bonded to the surface of the helium balloon, and the inflation and deflation operations of the helium balloon are completed by switching the switch of the inflation and deflation pump control line. At the same time, the inflation and deflation pump needs to be partially modified, and the built-in power line and control line of the inflation and deflation pump are modified and fixed together with the composite cable, and the power interface of the control line is placed on the ground to facilitate the control of inflation and deflation operations;

[0013] In the ground inflation and ground deflation working mode, the inflation and deflation pump is placed on the ground to perform inflation and deflation operations on the helium balloon on the ground.

[0014] In some optional implementation schemes, when performing the launch operation, the mooring cable is fixed at the same force point so that the buoyancy of the helium balloon, the gravity of the helium balloon antenna and its accessories, and the tension of the mooring cable are as vertical as possible to facilitate the uniform and stable rise of the helium balloon antenna. The inflation and deflation pump is interconnected with the air nozzle of the helium balloon, and the inflation and deflation pump is turned on and off by switching the control switch on the ground.

[0015] In some optional implementation schemes, during the recovery, the inflation and deflation pump is bonded to the surface of the helium balloon, the air nozzle of the inflation and deflation pump is interconnected with the air hole of the helium balloon, the switch control line of the inflation and deflation pump is placed on the ground through a composite radio frequency cable, and the helium inside the helium balloon is pumped out by controlling the inflation and deflation pump switch, thereby changing the buoyancy value of the helium balloon. When the buoyancy of the helium balloon is less than the gravity generated by the helium balloon antenna and its accessories, the helium balloon will fall;

[0016] Alternatively, during recovery, several mooring cables are fixed under the helium balloon. If the tension of the mooring cables and the gravity generated by the helium balloon and its accessories are greater than the buoyancy generated when the helium balloon is filled with helium, the helium balloon can be descended and recovered.

[0017] In some optional embodiments, the fixing of the antenna includes: using a plurality of ropes, each rope is tied to a reserved hook, and the tension that each rope can withstand is greater than the pulling force that needs to be provided; using a tether to tie all the ropes together, and ensuring the balance of forces in the vertical direction and that each rope is evenly stressed; dividing all the knotted ropes into a plurality of strands, each strand containing the same number of ropes, and then respectively knotting each strand with the corresponding separately provided rope and fixing it to a fixed point on the ground.

[0018] In some optional embodiments, the attitude adjustment of the helium balloon in the antenna includes: reserving a number of directional control cables, the angle between each cable is 90°, and according to the principle of force balance, applying tension to the mooring cable and the directional control cable to complete the attitude adjustment of the helium balloon antenna in the horizontal direction.

[0019] In some optional embodiments, a duplexer is disposed on the surface of the helium balloon, or a radio frequency cable on the helium balloon is connected to a duplexer on the ground to transmit a signal received by an antenna through the duplexer.

[0020] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0021] (1) Ultra-wideband antennas can increase channel capacity, have good anti-interference capabilities, and can achieve rapid signal transmission. At the same time, by conforming to the helium balloon to elevate the antenna, the influence of the earth's curvature radius and buildings near the ground surface can be effectively avoided during long-distance transmission. Compared with the traditional steel frame elevation method of base stations, this antenna is more flexible and mobile, and the antenna elevation speed is fast and the cost is low. It can be used for temporary relay of long-distance rapid transmission between sea and land platforms during wartime.

[0022] (2) Compared with traditional ultra-wideband antennas, the present invention has the advantage of a wider low-frequency band. The present invention has good directional radiation characteristics and omnidirectional radiation characteristics. The present invention is light in weight, can conform to the helium balloon, rise to an altitude of more than 30 meters, and work stably. The antenna of the present invention is highly efficient and has a high gain. The coaxial impedance matching port of the present invention can be directly connected to the SMA head, which is convenient for connection and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1The characteristic impedance and reflection coefficient of a bottom-fed ultra-wideband omnidirectional inflatable antenna provided by an embodiment of the present invention, wherein (a) is the impedance characteristic and (b) is the reflection coefficient;

[0024] Figure 2 This is an overall architecture diagram of a helium balloon antenna provided by an embodiment of the present invention;

[0025] Figure 3 is a schematic diagram of a specific onboard testing system provided by an embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of the inflation and deflation principle of a balloon provided by an embodiment of the present invention;

[0027] Figure 5 This is a schematic diagram of helium balloon antenna control provided by an embodiment of the present invention;

[0028] Figure 6 It is a communication link diagram of a helium balloon antenna system provided by an embodiment of the present invention;

[0029] Figure 7 It is a schematic diagram of a design solution provided by an embodiment of the present invention;

[0030] Figure 8 This is a schematic diagram of a second design solution provided by an embodiment of the present invention;

[0031] Fig. 9 It is a schematic diagram of the overall structure of an antenna provided by an embodiment of the present invention;

[0032] Fig.10 is a schematic diagram of a specific structure of an antenna provided by an embodiment of the present invention;

[0033] Fig.11 is a schematic diagram of an upper and lower conductor reinforcement device provided by an embodiment of the present invention;

[0034] Fig.12 It is a schematic structural diagram of a lower conductor feeding device provided by an embodiment of the present invention;

[0035] Fig.13 It is a cross-sectional view of a bottom-fed ultra-wideband omnidirectional inflatable antenna provided by an embodiment of the present invention;

[0036] Fig.14 The embodiment of the present invention provides a bottom-fed ultra-wideband omnidirectional inflatable antenna pattern;

[0037] Fig.15 This is a gain curve of a bottom-fed ultra-wideband omnidirectional inflatable antenna provided by an embodiment of the present invention;

[0038] Among them, 1 is an upper conductor radiation structure, 2 is an upper and lower conductor reinforcement device, 3 is a lower conductor feeding device, 4 is an upper sleeve structure of the upper and lower conductor reinforcement device, 5 is an auxiliary integrated structure of the upper and lower conductor reinforcement device placed inside the upper conductor radiation structure and fixed to the upper sleeve, 6 is a lower sleeve structure of the upper and lower conductor reinforcement device, 7 is an upper and lower sleeve connection reinforcement column structure of the upper and lower conductor reinforcement device, 8 is a rivet hole of the upper and lower conductor reinforcement device connected to the upper conductor, 9 is a rivet hole of the upper and lower conductor reinforcement device connected to the lower conductor, 10 is a middle sleeve structure, 11 is a transverse rib, 12 is a longitudinal rib, 13 is a rib hole, and 14 is a cable structure. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0040] The present invention proposes a biconical ultra-wideband omnidirectional radiating antenna that can conform to a helium balloon. The height of the antenna's ascent and descent is controlled by controlling the buoyancy of the helium balloon. The antenna can freely control the ascent altitude under the conditions permitted by the buoyancy of the helium balloon. Simulation and experimental results show that the 10dB impedance bandwidth of the ultra-wideband omnidirectional radiating balloon antenna is 200-425MHz, the relative bandwidth reaches 2.13:1, and the radiation pattern has good omnidirectional radiation characteristics in the horizontal plane. At the same time, the balloon antenna can fly freely in the range of 0-30 meters and has stable omnidirectional radiation characteristics.

[0041] The present invention needs to solve the lifting and climbing requirements of the ultra-wideband antenna for the helium balloon antenna, and should fully consider the antenna body design technology, ultra-wideband antenna technology, low-altitude tethered balloon technology, back-end signal transceiver conversion technology, balloon antenna fast inflation and deflation technology, fast transceiver balloon antenna technology and other issues in terms of lightness, miniaturization, anti-folding, anti-fading and easy manufacturing. The following technical solutions are adopted to achieve this, including:

[0042] 1) Ultra-wideband antenna design technology

[0043] A uniform transmission line can guide a plane traveling wave. An infinitely long biconical antenna can be regarded as a uniform transmission line that guides a spherical traveling wave outward. Therefore, a biconical antenna can be equivalent to a uniform transmission line characteristic. An infinitely long biconical antenna has a constant characteristic impedance. At this time, the radiation characteristics of the antenna are not related to the operating frequency, and a wider operating band characteristic can be achieved. Therefore, the impedance characteristics and radiation pattern characteristics of the biconical antenna only depend on the cone angle θ. 0 , the characteristic impedance of the antenna is:

[0044] Z=120lncot(θ 0 / twenty one)

[0045] The normalized direction map is:

[0046] F(θ)=sinθ 0 / sinθ (θ 0 ≤θ≤π-θ 0 ) (2)

[0047] Infinitely long biconical antennas do not actually exist, but through improvements, the characteristic impedance of biconical antennas is reduced and is higher than the characteristic impedance of monoconical antennas. Therefore, impedance matching with the feeder can be achieved within a smaller cone angle range, while still having a certain impedance invariance within a broadband range. The antenna impedance curve of the present invention is shown in FIG. Figure 1 As shown in (a), the impedance value is basically maintained at about 36dB in the range of 200-425MHz, with a minimum impedance value of 32dB and a maximum value of about 38dB, with a difference of about 6dB. The impedance of the antenna has a certain invariant stability in a wider working frequency band. Figure 1 (b) shows the S parameters, and it can be seen that the antenna has good impedance matching characteristics in the range of 200 to 425 MHz. The 10 dB impedance bandwidth of the antenna reflection coefficient is 2.13:1, which has good ultra-wideband characteristics.

[0048] 2) Main design technology of the launch antenna

[0049] In order to ensure the accuracy, reliability and safety of the antenna in the air, several accessories are added to the helium balloon antenna. The overall structure of the helium balloon antenna is shown in the figure below. Figure 2As shown, the schematic diagram of the helium balloon antenna equipped with the test system is shown in Figure 3. Among them, cable A is a control cable for adjusting the height of the balloon and the landing. Four cables A are symmetrically fixed around the central axis of the helium balloon. Only two cables are drawn in the figure and are represented by A1 and A2 respectively. In order to prevent the upper and lower radiators of the helium balloon antenna from falling off or deforming due to external factors such as wind resistance, which may affect the normal working performance of the helium balloon antenna, cable B is used to fix the upper and lower radiators of the antenna to make the structure of the helium balloon antenna more stable and reliable. Similarly, four cables B are partially fixed to the lower conductor of the helium balloon antenna symmetrically around the central axis of the helium balloon. Only two are marked in the schematic diagram, represented by cables B1 and B2 respectively. In order to prevent the cable F connected to the inflation and deflation pump G from being damaged due to force, the load-bearing steel wire rope and the cable can be bonded and fixed with the C cable, and the weight borne by the cable can be transferred to the steel wire rope to make a composite cable, so as to better protect the RF cable. The schematic diagrams are shown in C1 and C2. G is a signal-controlled inflation and deflation pump, which completes the inflation and deflation operation of the inflation and deflation pump through the F line to complete the sending and receiving signals. In the figure, H is a flexible mesh metal net attached to the surface of the helium balloon and the resin material, I is a helium balloon, J is a wedge plate, D is a steel wire rope used to control the balloon; E is a radio frequency cable, which is used for signal transmission between the antenna and the ground back-end signal transceiver converter.

[0050] 2) Rapid inflation and deflation design technology

[0051] The schematic diagram of the inflation and deflation principle of the antenna balloon is as follows Figure 4 As shown. The air pump has the functions of inflation and deflation, and can be switched by an electronically controlled switch. The specific inflation and deflation rate, weight, and volume can be adjusted according to actual needs, but the principle of matching inflation and deflation time with weight and volume should be followed to shorten the inflation and deflation time as much as possible. The placement of the air pump depends on the inflation and deflation working mode:

[0052] a) Inflate on the ground and deflate in the air

[0053] In this working mode, the inflation and deflation pump is bonded to the surface of the balloon, and the inflation and deflation of the balloon is completed by switching the switch of the inflation and deflation pump control line. At the same time, the inflation and deflation pump needs to be partially modified, the power line and control line built into the inflation and deflation pump are modified, fixed together with the composite cable, and the power interface of the control line is placed on the ground to facilitate the control of inflation and deflation operations.

[0054] Considering that the air pump itself has a certain weight, the gravity of the air pump itself needs to be taken into account when calculating the gravity generated by experimental accessories such as balloons.

[0055] b) Ground inflation and ground deflation

[0056] In this working mode, the inflation and deflation pump does not need to be fixed on the surface of the balloon. The inflation and deflation pump can be placed on the ground to perform inflation and deflation operations on the balloon on the ground.

[0057] Comparing the two working modes a) and b), when the balloon antenna is not launched to a high altitude, the balloon antenna can be pulled to the ground by manual recovery on the ground and deflated using mode b). However, when the balloon antenna is launched to a high altitude, the manual recovery method is inefficient and mode a) should be used to deflate in the air to facilitate the rapid recovery of the balloon antenna.

[0058] 3) Balloon antenna rapid recovery and control design technology

[0059] a) Balloon launch

[0060] The helium balloon antenna and its accessories are fixed at the same stress point by the mooring cable, so that the buoyancy of the helium, the gravity of the helium balloon antenna and its accessories and the tension of the mooring cable are as vertical as possible, which is convenient for the uniform and stable rise of the helium balloon antenna. The inflation and deflation pump is interconnected with the air nozzle of the helium balloon, and the inflation and deflation pump is turned on and off by switching the control switch on the ground.

[0061] b) Balloon recovery

[0062] (1) Semi-automatic deflation design

[0063] The inflation and deflation pump is bonded to the surface of the balloon, the air nozzle of the inflation and deflation pump is interconnected with the air hole of the helium balloon, and the switch control line of the inflation and deflation pump is placed on the ground through a composite radio frequency cable. The helium inside the helium balloon is extracted by controlling the inflation and deflation pump switch, thereby changing the buoyancy value of the helium balloon. When the buoyancy of the helium balloon is less than the gravity generated by the helium balloon antenna and its accessories, the helium balloon will fall.

[0064] (2) Human resource recovery design

[0065] Several mooring cables are fixed under the helium balloon. If the tension of the mooring cables and the gravity generated by the helium balloon and its accessories are greater than the buoyancy generated when the helium balloon is filled with helium, the helium balloon can be descended and recovered. Here, human power is used to achieve the recovery of the helium balloon.

[0066] c) Control

[0067] Helium balloon antenna control schematic diagram Figure 5 The control of a balloon in the air consists of two parts: (1) fixation; (2) balloon attitude adjustment.

[0068] Working principle: Based on the knowledge of force balance and dynamics, the vertical balance is achieved between the buoyancy of helium and the gravity of the helium balloon antenna + the tension of the mooring cable, and the horizontal balance is achieved between the wind force and the tension of the mooring cable, thereby ensuring the stability of the helium balloon antenna.

[0069] Solution Design:

[0070] a. Fixed

[0071] (1) Use 12 ropes, each tied to a reserved hitch. The tension that each rope can withstand must be greater than the pulling force we need to provide. The length of the rope is about 5 meters.

[0072] (2) Use a tether to tie the 12 ropes together to firstly ensure the balance of vertical forces and secondly ensure that each rope is evenly stressed.

[0073] (3) Divide the 12 knotted ropes into four strands, each containing three ropes. Then tie the four strands of rope with four 30-meter-long ropes to ensure that the balloon antenna can be sent 30 meters into the air.

[0074] b. Balloon posture adjustment

[0075] Four directional control cables are reserved, and the angle between each cable is 90°. According to the principle of force balance, by applying tension to the mooring cables and the directional control cables, the attitude adjustment of the helium balloon antenna in the horizontal direction can be completed.

[0076] 4) Back-end signal transceiver conversion technology

[0077] The communication link framework for back-end signal transmission and reception is as follows Figure 6 As shown. When the balloon antenna rises to a certain height, it transmits the signal to the wireless channel in the air, achieving stable and reliable communication performance at a long distance. Considering the actual use environment, the design index parameters are comprehensively evaluated to establish a stable and reliable communication link system.

[0078] Two design schemes are proposed, each considering different situations. The first design scheme is to place the duplexer on the surface of the balloon and let it rise with the balloon (e.g. Figure 7 As shown in the figure), the cable loss of this scheme is small, but it places high demands on the balloon's load-bearing capacity. The second design scheme places the duplexer on the ground and connects it via a longer RF cable (as shown in the figure). Figure 8 The disadvantage of this scheme is that the loss introduced by the cable is large, but the advantage is that it reduces the load on the balloon and facilitates the balloon's ascent. Design Scheme 1 is ahead of Design Scheme 2 in terms of performance; Design Scheme 2 requires a higher-power transmitter to achieve a more ideal performance.

[0079] In an embodiment of the present invention, Fig. 9 The invention provides an ultra-wideband omnidirectional inflatable antenna with bottom feeding. Fig.10 yes Figure 8 Exploded diagram of . Fig.11 , 12 for Figure 8 Schematic diagram of specific parts description. Fig.13 yes Figure 8 Cross-sectional view along the zx plane of the rectangular coordinate system (with the axis of the coaxial line as the z axis).

[0080] The bottom-fed ultra-wideband omnidirectional inflatable antenna provided by the present invention comprises: an upper conductor radiation structure 1 and a lower conductor feeding device 3 are connected through an upper and lower conductor reinforcement device 2, and the specific connection method is: the auxiliary integrated structure 5 of the upper and lower conductor reinforcement device 2, which is placed inside the upper conductor radiation structure and fixed to the upper sleeve, is placed inside the upper conductor radiation structure 1, and the upper sleeve structure 4 of the upper and lower conductor reinforcement device 2 is placed outside the upper conductor radiation structure 1, that is, the upper sleeve structure 4 of the upper and lower conductor reinforcement device and the auxiliary integrated structure 5 of the upper and lower conductor reinforcement device, which is placed inside the upper conductor radiation structure and fixed to the upper sleeve, are used to sandwich the upper conductor radiation structure 1 in the middle and fix it by loading rivets through the rivet holes 8 of the upper and lower conductor reinforcement device connected to the upper conductor. The lower sleeve structure 6 of the upper and lower conductor reinforcement device is transitioned through the middle sleeve structure 10, and in order to strengthen the supporting strength, three groups of upper and lower sleeve connection reinforcement column structures 7 of the upper and lower conductor reinforcement device are placed along the center line, with two in each group. The lower sleeve structure 6 of the upper and lower conductor reinforcement device is sleeved outside the lower conductor feeding device 3 and fixed by loading rivets through the rivet holes 9 of the upper and lower conductor reinforcement device connected to the lower conductor. The upper sleeve structure 4 of the upper and lower conductor reinforcement device, the auxiliary integrated structure 5 of the upper and lower conductor reinforcement device placed inside the upper conductor radiation structure and fixed to the upper sleeve, the lower sleeve structure 6 of the upper and lower conductor reinforcement device, and the upper and lower sleeve connection reinforcement column structure 7 of the upper and lower conductor reinforcement device are tightly connected into a whole, which has a strong anti-torsion ability.

[0081] Furthermore, in order to reduce weight to achieve high-altitude flight capability, the lower conductor feed device 3 adopts a hollow structure, and in order to enhance the structural strength, 6 longitudinal ribs 12 are placed longitudinally inside, 2 transverse ribs 11 are placed transversely, and a number of rib holes 13 are punched on the ribs.

[0082] Furthermore, the upper sleeve structure 4 of the upper and lower conductor reinforcement devices, the lower sleeve structure 6 of the upper and lower conductor reinforcement devices and the upper and lower sleeve connection reinforcement column structure 7 of the upper and lower conductor reinforcement devices are made of resin material using 3D printing technology and have a dielectric constant of 3.

[0083] The lower conductor feeding device 3 is also made of resin material using 3D printing technology, with a dielectric constant of 3. A layer of copper film is tightly covered on the outer layer and connected to the outer conductor of the cable. The cable is inserted into the through hole of the lower conductor feeding device 3. After extending, the cable shielding layer is peeled off to expose the inner conductor and connected to the upper conductor radiation structure 1 to achieve feeding.

[0084] The ultra-wideband working principle of the present invention is as follows:

[0085] like Figures 9 to 13 As shown, the radio frequency excitation of the bottom-fed ultra-wideband omnidirectional inflatable antenna provided by the present invention is fed from the bottom cable structure 14. Since the Babinet principle describes the relationship between the solutions of two magnetic field problems with complementary structures and dual sources, it is used in antenna engineering to conveniently derive the radiation characteristics and self-complementary characteristics of its equivalent complementary antenna from the radiation characteristics of a known antenna, which can lead to non-frequency-variant performance. The self-complementary structure is a structure that accurately covers its complementary structure by translation and (or) rotation means, and the input impedance of the self-complementary antenna is equal to the input impedance of its complementary antenna. Therefore, based on the basic principle that the input impedance of the self-complementary antenna is independent of frequency, the upper conductor radiation structure 1 is used as a conical structure with good ultra-wideband characteristics, and the lower conductor feeding device 3 is designed as a combination of a cylinder and a hemisphere, that is, it has the characteristics of the plane ground of a single cone antenna and the lower conductor transition structure of a double cone antenna. In addition, since the bottom-fed ultra-wideband omnidirectional radiation inflatable antenna can realize high-altitude flight operations, the lower conductor feeding device 3 has been designed to be miniaturized and lightweight, and the capacitance and inductance effects of the antenna can be adjusted through the plane cylinder to achieve ultra-wideband characteristics of impedance bandwidth.

[0086] like Fig.14 The directional diagram at the center resonant frequency of this embodiment is shown. Fig.14 It can be seen that the main radiation direction is in the horizontal plane, that is, θ = 90°, and because the antenna is a circularly symmetrical model, the antenna has good omnidirectional radiation characteristics.

[0087] like Fig.15 The gain curve within the frequency band obtained by simulation of this example is shown. It can be seen that the minimum gain is about 2.4dB, the maximum gain is about 3.6dB, and the gain roll-off is relatively smooth in the entire frequency band.

[0088] It should be pointed out that, according to the needs of implementation, the various steps / components described in this application can be split into more steps / components, and two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0089] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A biconical bottom-fed ultra-wideband omnidirectional radiating antenna conformal to a helium balloon, characterized in that: include: An upper conductor radiation structure, a lower conductor feeding device and upper and lower conductor reinforcement devices, wherein the upper conductor radiation structure and the lower conductor feeding device are connected through the upper and lower conductor reinforcement devices; The upper conductor radiation structure is a hollow conical patch, conforming to the helium balloon and connected to the inner conductor of the coaxial line; The lower conductor feeding device is a combination of a cylinder and a semicircle, with a hollow center, connected to the outer conductor of the coaxial line; The upper and lower conductor reinforcement devices are bidirectional sleeve structures that respectively sleeve the upper conductor radiation structure and the lower conductor feeder, and are connected to the upper conductor radiation structure and the lower conductor feeder by studs, so that the upper conductor radiation structure and the lower conductor feeder become a whole; An inflation and deflation pump is arranged on the helium balloon, and the inflation and deflation pump completes the sending and receiving signals through the F line to realize the inflation and deflation operation of the inflation and deflation pump; In the working mode of inflating on the ground and deflation in the air, the inflation and deflation pump is bonded to the surface of the helium balloon, and the inflation and deflation operations of the helium balloon are completed by switching the switch of the inflation and deflation pump control line. At the same time, the inflation and deflation pump needs to be partially modified, and the built-in power line and control line of the inflation and deflation pump are modified and fixed together with the composite cable, and the power interface of the control line is placed on the ground to facilitate the control of inflation and deflation operations; In the ground inflation and ground deflation working mode, the inflation and deflation pump is placed on the ground to inflate and deflate the helium balloon on the ground; When the lift is in progress, the mooring cable is fixed at the same stress point so that the buoyancy of the helium, the gravity of the helium balloon antenna and its accessories, and the tension of the mooring cable are as vertical as possible, which is convenient for the uniform and stable rise of the helium balloon antenna. The inflation and deflation pump is interconnected with the air nozzle of the helium balloon, and the inflation and deflation pump is turned on and off by switching the control switch on the ground. During the recovery, the inflation and deflation pump is bonded to the surface of the helium balloon, the air nozzle of the inflation and deflation pump is interconnected with the air hole of the helium balloon, the switch control line of the inflation and deflation pump is placed on the ground through a composite radio frequency cable, and the helium inside the helium balloon is pumped out by controlling the inflation and deflation pump switch, thereby changing the buoyancy value of the helium balloon. When the buoyancy of the helium balloon is less than the gravity generated by the helium balloon antenna and its accessories, the helium balloon will fall; Alternatively, during recovery, several mooring cables are fixed under the helium balloon. If the tension of the mooring cables and the gravity generated by the helium balloon and its accessories are greater than the buoyancy generated when the helium balloon is filled with helium, the helium balloon can be descended and recovered.

2. The ultra-wideband omnidirectional radiating antenna according to claim 1, characterized in that: A plurality of cables No. A are fixed symmetrically on the central axis of the helium balloon; a plurality of cables No. B are used to be partially fixed symmetrically around the central axis of the helium balloon and to the lower conductor feeding device.

3. The ultra-wideband omnidirectional radiating antenna according to claim 2, characterized in that: The load-bearing steel wire rope is bonded and fixed to the cable using a C-cable, and the weight borne by the cable is transferred to the steel wire rope to produce the composite cable for protecting the radio frequency cable.

4. The ultra-wideband omnidirectional radiating antenna according to claim 1, characterized in that: The fixing of the antenna includes: using a plurality of ropes, each rope is tied to a reserved hook, and the tension that each rope can withstand is greater than the pulling force that needs to be provided; using a tether to tie all the ropes together, and ensuring the balance of forces in the vertical direction and that each rope is evenly stressed; dividing all the knotted ropes into a plurality of strands, each strand containing the same number of ropes, and then respectively knotting each strand of rope with a corresponding rope provided and fixing them to a fixed point on the ground.

5. The ultra-wideband omnidirectional radiating antenna according to claim 4, characterized in that: The helium balloon attitude adjustment in the antenna includes: reserving a number of direction control cables, the angle between each cable is 90°, and according to the force balance principle, applying tension to the mooring cable and the direction control cable to complete the attitude adjustment of the helium balloon antenna in the horizontal direction.

6. The ultra-wideband omnidirectional radiating antenna according to claim 1, characterized in that: A duplexer is arranged on the surface of the helium balloon, or the helium balloon is connected to a duplexer on the ground through a radio frequency cable, so as to transmit the signal received by the antenna through the duplexer.

Images