CN115732905B - Airborne shortwave folded dipole antenna - Google Patents
Airborne shortwave folded dipole antennaInfo
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- CN115732905B CN115732905B CN202110990878.4A CN202110990878A CN115732905B CN 115732905 B CN115732905 B CN 115732905B CN 202110990878 A CN202110990878 A CN 202110990878A CN 115732905 B CN115732905 B CN 115732905B
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Abstract
本发明公开了一种机载短波折合振子天线，包括：两个平行的折合振子，分别接相位差为180°的馈电信号，折合振子包括弯折结构、直条金属结构、两个L型枝节加载结构以及金属过渡结构；弯折结构由多个金属枝节依次首尾连接构成，用于延长电流路径；直条金属结构一端为馈电点，另一端连接金属过渡结构；两个L型枝节加载结构分别位于直条金属结构的两侧，其短边共同连接直条金属结构的一点，其长边均平行于直条金属结构且向直条金属结构上的馈电行进方向延伸；金属过渡结构另一端连接弯折结构，以与弯折结构和直条金属结构一起形成结构开放的金属环路。本发明可在实现机载短波天线小型化的同时，保证天线拥有较高的增益。
This invention discloses an airborne shortwave folded dipole antenna, comprising: two parallel folded dipoles, each connected to a feed signal with a 180° phase difference; each folded dipole includes a bent structure, a straight metal structure, two L-shaped stub loading structures, and a metal transition structure; the bent structure is composed of multiple metal stubs connected end-to-end to extend the current path; one end of the straight metal structure is the feed point, and the other end is connected to the metal transition structure; the two L-shaped stub loading structures are located on both sides of the straight metal structure, their short sides connecting to a common point on the straight metal structure, and their long sides extending parallel to the straight metal structure and in the feed direction on the straight metal structure; the other end of the metal transition structure is connected to the bent structure, forming an open metal loop together with the bent structure and the straight metal structure. This invention can achieve miniaturization of the airborne shortwave antenna while ensuring high antenna gain.
Description
Technical Field
The invention belongs to the technical field of antennas, and particularly relates to an airborne shortwave folded dipole antenna.
Background
The short wave communication is radio communication realized by using electromagnetic waves with a frequency range of 3mhz to 30 mhz. The short wave communication has the characteristics of simple equipment, easy maintenance and long transmission distance, and is widely applied to the field of airborne and carrier-borne communication. The airborne short-wave communication system taking the short-wave antenna as the core plays a significant role in realizing long-distance communication for the aircraft. With the vigorous development of wireless communication technology and aerospace industry, airborne equipment is more diversified and integrated, and a small-sized and broadband antenna is easier to cope with complex electromagnetic environment, so that the antenna has important significance in the aspects of modern electronic countermeasure and stealth survivability. To ensure good communication, the on-board antenna should have an omni-directional horizontal pattern.
In the prior art, most of airborne short wave antennas are telescopic antennas installed on an aircraft platform, and the antennas are large in size and exposed out of the tail of the aircraft. Although the telescopic antenna can generate an omnidirectional pattern, the telescopic antenna is exposed out of the plane platform, so that the aerodynamic performance of the plane is easily affected, and the concealment is poor. Also, the need for a higher gain for the antenna for long-range communications has led to the need for a larger size for whip antennas.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides an airborne shortwave folded dipole antenna.
The technical problems to be solved by the invention are realized by the following technical scheme:
An airborne short wave folded dipole antenna is hidden and installed on an airplane body, and comprises two parallel folded vibrators, wherein the two folded vibrators are respectively connected with feed signals with a phase difference of 180 degrees, each folded vibrator comprises a bending structure, a straight strip metal structure, two L-shaped branch loading structures and a metal transition structure,
The bending structure is formed by sequentially connecting a plurality of metal branches end to end and is used for prolonging the current path in the folded vibrator;
One end of the straight strip metal structure is a feed point of the airborne shortwave folded dipole antenna, and the other end of the straight strip metal structure is connected with the metal transition structure;
The two L-shaped branch loading structures are respectively positioned at two sides of the straight strip metal structure, the short sides of the two L-shaped branch loading structures are commonly connected with one point on the straight strip metal structure, and the long sides are parallel to the straight strip metal structure and extend to the feed advancing direction on the straight strip metal structure;
And one end of the metal transition structure is connected with the straight strip metal structure, and the other end of the metal transition structure is connected with the bending structure so as to form a metal loop with an open structure together with the bending structure and the straight strip metal structure.
Optionally, the airborne short wave folded dipole antenna further comprises a balun for balancing the current amplitude of the feed signals entering the two folded dipoles.
Optionally, the airborne short wave folded dipole antenna further comprises an antenna tuner, wherein the antenna tuner is used for matching the input impedance and the external impedance of the airborne short wave folded dipole antenna.
Optionally, the antenna tuner is connected to an external transmitter via a radio frequency coaxial cable or a radio frequency coaxial connector.
Optionally, in the bending structure, the metal branches connected end to end are mutually perpendicular.
Optionally, the length of the folded dipole is 0.28λ -0.4λ, the width of the folded dipole is 0.001 λ -0.003 λ, the distance between the two folded dipoles is 0.13 m-0.18 m, and λ is the working wavelength of the antenna.
Optionally, the plurality of metal branches, the straight metal structure, the L-shaped branch loading structure and the metal transition structure are all composed or formed of metal strips, and the structurally connected metal strips are welded together.
Optionally, the widths of the metal strips forming the plurality of metal branches, the straight strip metal structure and the metal transition structure are 10 mm-26 mm and 0.8 mm-1.2 mm, and the widths of the metal strips forming the L-shaped branch loading structure are narrower than those of the metal strips forming the straight strip metal structure.
Optionally, the other end of the bending structure, which is not connected to the metal transition structure, is connected to the aircraft structure ground.
In the airborne shortwave folded dipole antenna provided by the invention, the two folded vibrators are arranged in parallel, namely, the two folded vibrators can be transversely arranged, so that the longitudinal height of the antenna can be obviously reduced, the antenna is suitable for being hidden and installed on an aircraft body, and the aerodynamic performance of the aircraft cannot be influenced. In addition, the two folded oscillators are respectively connected with feed signals with 180 DEG phase difference, so that the feed signals input into the antenna can generate a radiation mode similar to a dipole when the surfaces of the two folded oscillators excite currents with equal amplitude and opposite directions. Each folded vibrator comprises a bending structure for prolonging the current path in the antenna, so that the electric length of the antenna is prolonged in a smaller size space, and the gain of the antenna is improved. And each folded vibrator is also provided with an L-shaped branch loading structure for improving the impedance characteristic of the antenna and further ensuring the high gain characteristic of the antenna. Therefore, the airborne short wave folded dipole antenna provided by the invention has the characteristics of high-gain radiation performance and miniaturized structure, and is suitable for long-distance communication under the condition of airborne hidden installation.
The present invention will be described in further detail with reference to the accompanying drawings.
Drawings
Fig. 1 is a schematic structural diagram of an airborne shortwave folded dipole antenna according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a folded dipole in the antenna of FIG. 1;
fig. 3 schematically illustrates an installation diagram of an airborne short wave folded dipole antenna according to an embodiment of the present invention;
Fig. 4 exemplarily shows the length and width dimensions of an airborne short wave folded dipole antenna provided by an embodiment of the present invention;
fig. 5 is a schematic structural diagram of another airborne shortwave folded dipole antenna according to an embodiment of the present invention;
Fig. 6 is a schematic structural diagram of another airborne shortwave folded dipole antenna according to an embodiment of the present invention;
Fig. 7 is a diagram illustrating an internal structure of an airborne shortwave folded dipole antenna according to an embodiment of the present invention;
FIGS. 8 (a), 8 (b) and 8 (c) show horizontal plane pattern contrast curves of the antenna provided by the embodiments of the present invention at 8MHz, 15MHz and 24MHz in simulation before and after loading an aircraft, respectively;
Fig. 9 shows simulation results of peak gain of the airborne short wave folded dipole antenna according to the change of frequency.
Detailed Description
The present invention will be described in further detail with reference to specific examples, but embodiments of the present invention are not limited thereto.
In order to achieve miniaturization of an airborne short wave antenna and ensure that the antenna has higher gain, the embodiment of the invention provides the airborne short wave folded dipole antenna which can be installed on an airplane body in a hidden mode, and the antenna comprises two parallel folded vibrators 1, wherein the two folded vibrators 1 are respectively connected with feed signals with the phase difference of 180 degrees, as shown in fig. 1. In this way, the feed signal fed into the antenna generates a dipole-like radiation pattern when the surfaces of the two folded oscillators 1 are excited with equal-amplitude opposite currents, thereby improving the out-of-roundness of the antenna pattern. It can be appreciated that the two folded oscillators 1 are arranged in parallel and can be arranged transversely relative to the aircraft fuselage, so that the longitudinal height of the antenna is obviously reduced, the antenna is more suitable for being installed on the aircraft fuselage in a hidden manner, and the aerodynamic performance of the aircraft is not affected.
Referring to fig. 2, each folded dipole 1 comprises a bending structure 11, a straight metal structure 14, two L-shaped branch loading structures 12 and a metal transition structure 13.
The bending structure 11 is formed by sequentially connecting a plurality of metal branches end to end, and is used for prolonging a current path in the folded vibrator 1. The lengths of these metal branches may or may not all be equal as shown in fig. 2. Preferably, the metal branches connected end to end are mutually perpendicular, so that better matching performance can be obtained, and of course, the effect of prolonging the current path can be achieved as well as the effect of not mutually perpendicular the metal branches connected end to end.
One end of the straight metal structure 14 is a feeding point 15 of the short wave carrying folded dipole antenna, and the other end is connected with the metal transition structure 13.
The two L-shaped branch loading structures 12 are respectively positioned at two sides of the straight strip metal structure 14, the short sides of the two L-shaped branch loading structures 12 are commonly connected with one point on the straight strip metal structure 14, and the long sides are parallel to the straight strip metal structure 14 and extend to the feed advancing direction on the straight strip metal structure 14;
the metal transition structure 13 has one end connected to the straight metal structure 14 and the other end connected to the bending structure 11 to form a metal loop with an open structure together with the bending structure 11 and the straight metal structure 14. It will be appreciated that the bent structure 11 is connected at one end to the metal transition structure 13 to its own feed input and at its other end to the structural ground of the aircraft in the actual installation scenario, for example to the metal structure of the aircraft fuselage body or to the tail front edge spar (see figure 3), thereby reducing the likelihood of performance degradation or loss of function of the antenna due to lightning strikes.
In practice, the plurality of metal branches in the bending structure 11, the straight metal structure 14, the L-branch loading structure 12 and the metal transition structure 13 are all formed or composed of metal strips. Preferably, the widths of the metal branches forming or forming the bending structure 11, the straight metal structure 14 and the metal strips of the metal transition structure 13 may be 10 mm-26 mm, and the thicknesses of the metal strips are 0.8 mm-1.2 mm, and the widths of the metal strips forming the L-branch loading structure 12 are narrower than the widths of the metal strips forming the straight metal structure 14, and the metal strips are preferably copper or gold. In this way it is ensured that the folded dipole 1 can withstand large transmission powers without causing excessive weight of the antenna. Therefore, the airborne shortwave folded dipole 1 antenna provided by the embodiment of the invention has the advantages of simple structure and convenience in processing, and the metal strips can be printed on the aircraft skin in a printing mode, so that the antenna is very suitable for conformal connection with the antenna, and the installation requirement of the antenna under the limited size of an airborne platform is met. In addition, in order to ensure structural stability of the antenna, an insulating material may be further used to fix the position of the folded array 1 in the embodiment of the present invention.
In the embodiment of the invention, each folded vibrator 1 comprises the bending structure 11, so that the current path in the antenna can be prolonged, the electric length of the antenna can be prolonged under the condition of smaller physical size, the size of the antenna can be effectively reduced, and the gain of the antenna can be improved. In addition, each folded vibrator 1 is also provided with an L-shaped branch loading structure 12, so that the impedance characteristic of the antenna can be improved, and the high-gain characteristic of the antenna is further ensured. Therefore, the airborne shortwave folded dipole 1 antenna provided by the embodiment of the invention has the characteristics of high-gain radiation performance and miniaturized structure, and is suitable for long-distance communication under the condition of airborne hidden installation.
Preferably, referring to fig. 4, the length of the folded dipole 1 in the embodiment of the present invention is 0.28λ -0.4λ, and the width is 0.001 λ -0.003 λ, where λ is the working wavelength of the antenna. The distance between the two folded oscillators 1 is preferably 0.13 m-0.18 m. It will be appreciated that the length direction of the folded dipole 1 is parallel to the direction of the straight metal structure 14, and correspondingly, the width direction of the folded dipole 1 is the direction in which the metal transition structure 13 extends towards both ends of itself.
In an alternative embodiment, the airborne short wave folded dipole 1 antenna provided by the embodiment of the invention may further comprise balun 2 for balancing the current amplitude of the feed signals into the two folded dipoles 1.
Referring to fig. 5, in this embodiment, a single-ended input rf signal of balun 2 is output by two differential output terminals, and two feed signals are respectively fed into two folded oscillators 1. In practice balun 2 may also be referred to as a balun, mainly for making the phase difference of the two feed signals closer to the ideal 180 °.
Based on the embodiment shown in fig. 5, in an alternative implementation manner, the on-board short wave folded dipole 1 antenna provided by the embodiment of the present invention may further include an antenna tuner 3, configured to match an input impedance and an external impedance of the on-board short wave folded dipole 1 antenna.
As shown in fig. 6, the antenna tuner 3 has an input connected to the external impedance and an output connected to the input of balun 2. The external impedance may be an output impedance of the external transmitter, or an output impedance of an external radio frequency circuit, or the like. The antenna tuner 3 may be connected to the transmitter via the rf coaxial line 4 or the rf coaxial connector, although the manner in which the antenna tuner 3 is connected to the transmitter is not necessarily the case.
In fig. 6, the specific working flow of the airborne short wave folded dipole 1 antenna is as follows, the radio frequency signal enters the antenna tuner 3 through the radio frequency coaxial line 4, the radio frequency signal with the maximum efficiency radiation energy is obtained through impedance matching, the matched radio frequency signal then enters the balun 2, and then is respectively sent to the folded dipole 1 of the upper layer and the lower layer through the feeder line to radiate to the external space.
After the antenna tuner 3 is additionally arranged, under the adaptation of the antenna tuner 3, the airborne shortwave folded dipole 1 antenna provided by the embodiment of the invention can realize impedance matching in a broadband, thereby having higher transmitting efficiency under the broadband working condition and being suitable for being applied to frequency hopping spread spectrum communication.
In a preferred embodiment, see fig. 7, the folded dipole 1 has a width W 1 of 0.018m and a thickness of 1mm, the distance between two folded dipoles 1 being 0.15m. The bending structure 11 comprises 6 sections of first metal branches, 3 sections of second metal branches and 8 sections of third metal branches, wherein the length L 1 of the first metal branches is 0.16m, the length L 2 of the second metal branches is 0.7m, and the length L 3 of the third metal branches is 0.15m. The length L 4 of the metal transition structure 13 is 0.29m. The length L 5 of the straight metal structure 14 is 2.87m. The length L 6 = 0.5m of the connection point of the short side of the L-shaped branch loading structure 12 and the straight metal structure 14 from the feeding point, the length L 7 = 2.22m of the long side of the L-shaped branch loading structure 12, the length L 8 = 0.04m of the short side, and the width W 2 of the long side and the short side are both 0.006m.
Based on the embodiment, the antenna is simulated to evaluate the performance of the airborne shortwave folded dipole antenna provided by the embodiment of the invention under the airborne condition. In the simulation process, the size of the aircraft platform is set to be 40m in length, 58m in span and 4.5m in height, and the antenna is arranged on the front edge of the tail wing of the aircraft. The electromagnetic field full-wave simulation software ANSYS HFSS and 19.0 are used for simulating the airborne short wave folded dipole antenna combined aircraft, and the simulation results are as follows:
Fig. 8 (a), 8 (b) and 8 (c) show horizontal plane pattern contrast curves of the antenna provided by the embodiment of the invention at 8MHz, 15MHz and 24MHz before and after loading the aircraft, respectively. The longitude coordinate of the polar coordinate curve is an angle, the range is 0-360 degrees, the latitude coordinate is the antenna gain, and the range is-20 dBi-5dBi.
Compared with the prior art, when the aircraft is not loaded, the airborne shortwave folded dipole antenna provided by the embodiment of the invention has good horizontal omnidirectional radiation characteristics at different frequency points in a frequency band, and the out-of-roundness of a directional diagram is less than 1dBi. After the airplane is loaded, the roundness of the horizontal pattern of the antenna is slightly changed due to the influence of the airplane, but the better horizontal omnidirectional radiation characteristic can be maintained in the horizontal direction, and the gain in the horizontal direction is larger than-5 dBi, so that the antenna provided by the embodiment of the invention is less influenced by the airplane body, and the antenna still has the characteristics of high gain and omnidirectional radiation after the airplane body is loaded.
Fig. 9 shows simulation results of peak gain of the airborne shortwave folded dipole antenna according to the embodiment of the invention along with frequency change, wherein the abscissa is frequency, the unit is MHz, the range is from 5 to 25MHz, the ordinate is the decibel value of the maximum gain amplitude, the unit is dBi, and the range is-4 dBi to 8dBi.
As can be seen from fig. 9, after loading an aircraft, the gain of the airborne shortwave folded dipole antenna provided by the embodiment of the invention is continuously increased along with the increase of the frequency in the frequency range of 5MHz-25MHz, the peak gain of the full-band antenna is higher than-5 dBi, the average gain is about 1.5dBi, the maximum gain reaches 4.4dBi, and the peak gain is greater than 0dBi when the frequency is greater than 10 MHz. Compared with the traditional pull rod type airborne short wave antenna, the airborne short wave folded dipole antenna provided by the embodiment of the invention has good gain characteristics on the basis of a simple structure, full-band peak gain is more than-5 dBi, and the out-of-roundness of a horizontal pattern is good, so that the high gain and the omnidirectional radiation of the airborne short wave antenna are realized, and the communication distance of an airborne short wave system can be increased.
In the description of this specification, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more features. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Further, one skilled in the art can engage and combine the different embodiments or examples described in this specification.
Although the application is described herein in connection with various embodiments, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed application, from a study of the drawings, the disclosure, and the appended claims.
The foregoing is a further detailed description of the invention in connection with the preferred embodiments, and it is not intended that the invention be limited to the specific embodiments described. It will be apparent to those skilled in the art that several simple deductions or substitutions may be made without departing from the spirit of the invention, and these should be considered to be within the scope of the invention.
Claims (9)
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| CN202110990878.4A CN115732905B (en) | 2021-08-26 | 2021-08-26 | Airborne shortwave folded dipole antenna |
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| CN202110990878.4A CN115732905B (en) | 2021-08-26 | 2021-08-26 | Airborne shortwave folded dipole antenna |
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| CN115732905B true CN115732905B (en) | 2026-02-03 |
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH384644A (en) * | 1960-12-26 | 1964-11-30 | Baumgartner Rudolf | Fully fed directional antenna for short and ultra short waves |
| CN101465477A (en) * | 2007-12-19 | 2009-06-24 | 株式会社东芝 | Antenna device and wireless device |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102009023514A1 (en) * | 2009-05-30 | 2010-12-02 | Heinz Prof. Dr.-Ing. Lindenmeier | Antenna for circular polarization with a conductive base |
| CN201508905U (en) * | 2009-09-08 | 2010-06-16 | 中兴通讯股份有限公司 | Antenna applied to handheld reader and handheld reader |
| JP5840942B2 (en) * | 2011-12-20 | 2016-01-06 | 三菱電線工業株式会社 | Folded dipole antenna |
| CN106602284A (en) * | 2016-11-30 | 2017-04-26 | 南京邮电大学 | Small-scale metal-resistant broadband tag antenna |
| CN208299027U (en) * | 2018-05-21 | 2018-12-28 | 华南理工大学 | A kind of differential feed directional diagram reconstructable aerial |
| CN109687152B (en) * | 2018-12-11 | 2020-08-11 | 南京邮电大学 | Microwave rectification antenna |
| CN112736423B (en) * | 2020-12-10 | 2023-03-21 | 重庆大学 | Compact low-profile differential filtering microstrip patch antenna |
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH384644A (en) * | 1960-12-26 | 1964-11-30 | Baumgartner Rudolf | Fully fed directional antenna for short and ultra short waves |
| CN101465477A (en) * | 2007-12-19 | 2009-06-24 | 株式会社东芝 | Antenna device and wireless device |
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