CN112366455B

CN112366455B - Asymmetric double-ridge horn antenna

Info

Publication number: CN112366455B
Application number: CN202011187672.XA
Authority: CN
Inventors: 倪涛; 魏明; 刘鹏; 王敏; 张欢; 万涛
Original assignee: CETC 20 Research Institute
Current assignee: CETC 20 Research Institute
Priority date: 2020-10-29
Filing date: 2020-10-29
Publication date: 2022-12-27
Anticipated expiration: 2040-10-29
Also published as: CN112366455A

Abstract

The invention provides an asymmetric double-ridge horn antenna, which adopts an open boundary structure and a central feeding mode, wherein two horn outer walls are arranged in parallel, the two horn outer walls and a waveguide part form a cavity with a U-shaped opening, a feeding coaxial line part is connected with the waveguide part and positioned outside the cavity, and double-ridge horn parts are respectively arranged on two inner sides of the two horn outer walls in the cavity formed by the horn outer walls. The invention adopts two different index forms as the double-ridge structure of the horn antenna, so that the horn antenna can adopt a central feed form.

Description

Asymmetric double-ridge horn antenna

Technical Field

The invention relates to the field of antennas, in particular to a horn antenna, which is designed based on an open boundary and has an asymmetric ridge structure, and can realize the center feed of a horn and simultaneously widen the impedance bandwidth and the directional diagram bandwidth of the antenna.

Background

The horn antenna has a wider directional diagram and impedance bandwidth, higher gain and radiation efficiency and lower side lobe, has a simple structure, is easy to process, can be used as a feed source of a reflecting surface, and can also be used as an independent antenna to be applied to a test system or a limited scanning array. Especially in the millimeter wave frequency band, the traditional microstrip antenna is not suitable any more due to the high wavelength length of the frequency band, and the horn antenna is more extensive in military and civil systems. The traditional horn antenna reduces the low-frequency cut-off frequency of the main antenna mode through the loading ridge structure, and achieves the purpose of widening the single-mode working bandwidth through reasonably designing the index form of the ridge structure. The invention provides an asymmetric double-ridge horn antenna, which is characterized in that the feeding point of the traditional ridge symmetric horn antenna is in a partial feeding form, in order to realize the central feeding of the antenna and facilitate the layout and the structural design of an active component after the antenna is used as a unit array, the feeding point is positioned in the center of an antenna short circuit board by designing two ridge structures to have different index forms, and meanwhile, the low-frequency matching characteristic of the antenna is further improved, and a wider working bandwidth is obtained.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides an asymmetric double-ridged horn antenna. The invention relates to a double-ridge horn antenna with ultra-wideband performance, which realizes center feed and simultaneously improves the low-frequency impedance matching characteristic of the antenna by designing the two ridges of the antenna to have curves with different index forms respectively.

The technical scheme adopted by the invention for solving the technical problems is as follows:

an asymmetric double-ridged horn antenna adopts an open boundary structure and a central feeding mode, and comprises a feeding coaxial line part (1), a waveguide part (2), a double-ridged horn part (3) and a horn outer wall (4) as shown in figure 1; wherein, two loudspeaker outer walls (4) parallel arrangement, two loudspeaker outer walls (4) form U type open-ended cavity with waveguide portion (2), and feed coaxial line portion (1) is connected waveguide portion (2), is located outside the cavity, and in the cavity that loudspeaker outer wall (4) formed, two inboards of two loudspeaker outer walls (4) are equipped with two spine loudspeaker portions (3) respectively.

The waveguide part (2) is an optimized rectangular double-ridge waveguide, the waveguide inner ridge 1 (21) and the waveguide inner ridge 2 (22) of the waveguide part (2) are metal blocks with different sizes, different characteristic impedances of the double-ridge waveguide are obtained by optimizing the height and the length of the inner ridges, and therefore good matching of the waveguide part and the feeding coaxial line is achieved.

The feed coaxial line part (1) comprises a coaxial line inner core (11), a coaxial line outer conductor (12) and a medium sleeve (13), the coaxial line inner core (11) is wrapped by a layer of medium sleeve (13), and the coaxial line outer conductor (12) is directly connected with a metal short circuit plate (23) of the waveguide part (2) in a short circuit way; the coaxial line outer conductor (12) passes through a reserved through hole on the metal short circuit board (23) and is directly inserted into the reserved through hole on the waveguide inner ridge 1 (21), so that coupling feeding is realized.

The ridge of the double-ridge horn part (3) is divided into an upper ridge (32) and a lower ridge (31), the upper ridge (32) and the lower ridge (31) are respectively located on the inner side of the horn outer wall (4), the curve parts of the upper ridge (32) and the lower ridge (31) are arranged oppositely, the upper ridge (32) and the lower ridge (31) have different curve forms, wherein the distance from one end, far away from the waveguide part (2), of the upper ridge (32) to the edge of the cavity opening at the point of the horn outer wall (4) is m, m is larger than 0, one end, far away from the waveguide part (2), of the lower ridge (31) extends to the edge of the cavity opening at the point of the horn outer wall (4), and the working bandwidth of the horn antenna is remarkably improved through the asymmetrical ridge structural design.

The curves of the upper ridge (32) and the lower ridge (31) are exponential curves or cubic bezier curves.

The waveguide inner ridge 1 (21) is connected with a lower ridge (31).

The horn outer wall (4) is of a metal structure with thickness, and the tail end (namely the edge of the horn outer wall at the U-shaped opening) is subjected to bevel cutting.

The invention has the advantages that the horn antenna can adopt a central feed mode because two different index modes are adopted as the double-ridge structure of the horn antenna, and compared with the traditional double-ridge horn antenna adopting a side feed symmetrical index mode, the invention has the advantages of wider working bandwidth and more convenience for forming an array antenna, and simultaneously has more adjusting variables and is convenient for performance optimization and engineering debugging.

Drawings

Fig. 1 is a perspective view of an asymmetric double-ridged horn antenna structure with open borders according to the present invention.

Fig. 2 is a cross-sectional view of an asymmetric double-ridged horn antenna structure with an open border according to the present invention, wherein fig. 2 (a) is a side view and fig. 2 (b) is a cross-sectional view.

FIG. 3 is a diagram showing the simulation result of the voltage standing wave ratio of the present invention.

FIG. 4 shows the simulation results of the far-field radiation pattern of the present invention at 10 GHz.

FIG. 5 shows the simulation results of the far-field radiation pattern of the present invention at 12 GHz.

FIG. 6 shows the simulation results of the far-field radiation pattern of the present invention at 15 GHz.

FIG. 7 shows the simulation results of the far-field radiation pattern of the present invention at 18 GHz.

Detailed Description

The invention is further illustrated with reference to the following figures and examples.

A double-ridge horn antenna with ultra-wideband characteristics adopts an open boundary structure and a center feeding mode, and the overall structure and a section view of the antenna are respectively shown in figures 1 and 2. The overall size of the antenna is 15mm × 12.5mm × 25mm (x × y × z).

The antenna is fed by adopting a 50 omega coaxial line, the coaxial line outer core (12) is directly connected with the metal short-circuit plate (23), the medium sleeve (13) wraps the coaxial line inner core (11), penetrates through a through hole reserved in the metal short-circuit plate (23), and is directly inserted into a through hole reserved in the waveguide inner ridge 1 (21) to realize coupling feeding.

The waveguide section (2) takes the form of a ridge waveguide, and a good match is obtained by optimizing the dimensions of the two inner ridges. The optimized inner ridge 1 (21) has the size of 3.2mm × 5.95mm × 2mm (x × y × z), and the inner ridge 2 (22) has the size of 3.2mm × 1.75mm × 1mm (x × y × z).

The ridges of the double-ridged horn portion (3) are divided into upper ridges (32) and lower ridges (31), wherein the upper ridges (32) have a curved form of y =0.28 × 2.6 ^(0.21×x) +1.22, the length of the upper ridge (32) is 13mm (z direction), and the distance between the end of the upper ridge and the horn opening is 8.6mm; the lower ridge (31) has a curved form of y =0.2 × 2.0 ^(0.21×x) +0.4, the lower ridge (31) has a length of 20mm (z direction) and its end extends to the horn opening position. Both ridges are 3.2mm thick (x direction).

The horn outer wall (4) was 1mm thick, and the end thereof (i.e., the horn opening portion) was subjected to bevel cutting.

Fig. 3 is a simulation result of the vswr of the antenna according to the present invention. It can be seen from fig. 3 that the voltage standing wave ratios of the antenna are less than 2 in the frequency band of 8-20 GHz. Fig. 4 to 7 are simulation results of far-field radiation patterns of the antenna of the present invention at different frequency points. As can be seen from the figure, the antenna can maintain good directivity in the range of 8-20GHz, and the problem of directional pattern lobe is not caused. In conclusion, the present invention has good broadband standing wave and directional pattern characteristics.

Claims

1. A double-ridge horn antenna with ultra-wideband performance is characterized in that:

the double-ridge horn antenna with the ultra-wideband performance realizes that a feed point is positioned in the center of an antenna short-circuit board by designing two ridge structures to have different index forms respectively, adopts an open boundary structure and a central feed mode and comprises a feed coaxial line part, a waveguide part, a double-ridge horn part and a horn outer wall; the feeding coaxial line part is connected with the waveguide part and positioned outside the cavity, and two inner sides of the two horn outer walls are respectively provided with a double-ridge horn part in the cavity formed by the horn outer walls;

the waveguide part is a section of rectangular double-ridge waveguide, the waveguide inner ridge 1 and the waveguide inner ridge 2 of the waveguide part are metal blocks with different sizes, and different characteristic impedances of the double-ridge waveguide are obtained by optimizing the height and the length of the inner ridge.

2. The dual ridged horn antenna with ultra-wideband performance as claimed in claim 1, wherein:

the part of the feed coaxial line comprises a coaxial line inner core, a coaxial line outer conductor and a medium sleeve, the coaxial line inner core is wrapped by a layer of medium sleeve, and the coaxial line outer conductor is directly connected with a metal short circuit plate of the waveguide part in a short circuit way; the coaxial line outer conductor passes through a through hole reserved on the metal short circuit plate and is directly inserted into the through hole reserved on the waveguide inner ridge 1, and therefore coupling feeding is achieved.

3. The dual ridged horn antenna with ultra-wideband performance as claimed in claim 1, wherein:

the ridge of two ridge horn portions divide into ridge and ridge down, go up the ridge and lie in the inboard of loudspeaker outer wall respectively with ridge down, the curve part of going up ridge and ridge down sets up relatively, and go up the ridge and have different curve forms with ridge down, wherein, the one end that waveguide portion was kept away from to the ridge is m at the point of loudspeaker outer wall to the distance at cavity opening border, m is greater than 0, the one end that waveguide portion was kept away from to the ridge down extends to cavity opening border at the point of loudspeaker outer wall, through asymmetric ridge structural design, the working bandwidth of horn antenna is improved.

4. The dual ridged horn antenna with ultra-wideband performance as claimed in claim 3, wherein:

the curves of the upper ridge and the lower ridge are exponential curves or cubic bezier curves.

5. The dual ridged horn antenna with ultra-wideband performance as claimed in claim 1, wherein:

the waveguide inner ridge 1 is connected with the lower ridge.

6. The dual ridged horn antenna with ultra-wideband performance as claimed in claim 1, wherein:

the outer wall of the horn is of a metal structure with thickness, and the edge of the outer wall of the horn at the U-shaped opening is subjected to oblique angle cutting treatment.