CN114759354A - Miniaturized broadband stable beam horn feed source antenna - Google Patents

Abstract

The invention discloses a miniaturized broadband stable beam horn feed source antenna, which relates to the technical field of antennas and comprises a waveguide horn, wherein the horn surface of the waveguide horn is provided with a plurality of grooves, the grooves are provided with first medium loads so as to control the beam shape in a broadband in the transverse direction, the relative dielectric constant of the first medium loads is more than 1, and the first medium loads are provided with metal coatings; and the second medium load is arranged at the aperture position of the waveguide horn and comprises a plurality of gradient structures, and the middle parts of the gradient structures are gradually reduced towards two ends so as to control the beam shape in the broadband in the longitudinal direction, thereby improving the directional diagram anisometry of the feed source. The contradiction of realizing wide bandwidth in small volume is solved, the feed source has the characteristics of miniaturization and light weight, and the feed source can be better and widely applied.

Description

Miniaturized Broadband Stabilized Beam Horn Feed Antenna

technical field

The invention relates to the technical field of antennas, in particular to a miniaturized broadband stable beam horn feed antenna.

Background technique

In order to ensure the radiation efficiency of the parabolic antenna, the -10dB beam width of the feed antenna should match the focal-to-diameter ratio of the reflector in the entire bandwidth. In order to reduce the shading effect of the feed on the paraboloid and to easily integrate multiple feeds, the size of the feed should meet the characteristics of miniaturization.

The current broadband parabolic antenna feeds are mainly realized in the form of logarithmic periodic antennas (such as eleven antennas) and corrugated horns.

(1) Logarithmic periodic antenna scheme: As an ultra-wideband antenna, the logarithmic periodic antenna has a very wide bandwidth coverage, and the bandwidth can be 10:1. Because of its ultra-wideband characteristics, it is often used as a feed for reflector antennas. In the article [1], an Eleven antenna composed of four log-periodic antennas is proposed, and its bandwidth reaches 6.5:1. The paper [2] designed a log-periodic dipole antenna (LPDA) composed of two log-periodic antennas, which achieved a bandwidth of 10:1.

The log-periodic antenna adopts a non-frequency-variable structure to achieve constant beam shape in the broadband. Different frequency radiation structures are fed in series by TEM transmission lines. The current path is long, resulting in large signal loss and reducing the antenna radiation efficiency. In addition, because the frequency is different, the position of the radiation will also change, resulting in the shift of the equivalent phase center and reducing the aperture efficiency. At the same time, the log-periodic antenna has high requirements on machining accuracy, which leads to the disadvantage that it cannot cover the high-frequency part.

(2) Corrugated horn antenna scheme: The corrugated horn antenna is used as a feed source, which can achieve high antenna efficiency in a wide bandwidth. The article [3] designed a corrugated horn antenna loaded with medium, the antenna works in 6.5-13.7GHz with a bandwidth of 71.3%, and its volume is 110mm×110mm×135mm.

The corrugated horn directly changes the shape of the radiation aperture, digs or embeds uneven depths (corrugated grooves) on the inner wall of the horn, controls the current distribution on the aperture surface and then controls the beam shape to achieve high aperture efficiency. In order to ensure the beam width in the wide band, the existing corrugated horn antenna needs a sufficient aperture size, resulting in a large volume and heavy weight; it has a large shielding on the paraboloid, which reduces the aperture efficiency.

The above two methods can both control the beam shape of the reflector antenna feed, but both have some limitations and design difficulties. The logarithmic period has the disadvantages of large loss, high processing accuracy requirements, inability to cover high frequency and unstable phase center. The corrugated horn has the disadvantage of being larger in size and heavier in weight.

[1].J.Yang et al.,"Cryogenic 2–13GHz Eleven Feed for ReflectorAntennas in Future Wideband Radio Telescopes,"in IEEE Transactions on Antennas and Propagation,vol.59,no.6,pp.1918-1934,June 2011 , doi: 10.1109/TAP.2011.2122229.

[2].O.Sushko,S.Piltyay and F.Dubrovka,"Symmetrically Fed 1–10GHz Log-Periodic Dipole Antenna Array Feed for Reflector Antennas,"2020IEEE UkrainianMicrowave Week(UkrMW),2020,pp.222-225,doi :10.1109/UkrMW49653.2020.9252778.

[3].H.Lee,J.Lee and J.Choi,"A corrugated horn antenna with adielectric lens for high gain performance,"2015International Symposium on Antennas and Propagation(ISAP),2015,pp.1-2.

SUMMARY OF THE INVENTION

The present invention aims to solve one of the above-mentioned technical problems in the prior art at least to a certain extent. Therefore, the embodiments of the present invention provide a miniaturized broadband stable beam horn feed antenna, which solves the contradiction of realizing a wide bandwidth in a small volume, and also makes the feed antenna have the characteristics of miniaturization and light weight, so that the feed antenna can be better widely used.

The miniaturized broadband stabilized beam horn feed antenna according to the embodiment of the present invention includes a waveguide horn, the horn surface of the waveguide horn is provided with a plurality of grooves, and the grooves are installed with a first medium loading, so as to align the horn in the lateral direction. The broadband inner beam shape is controlled, the relative permittivity of the first medium loading is greater than 1, and the first medium loading is provided with a metal coating; and the second medium loading is installed on the waveguide horn The second medium loading includes a plurality of grading structures, the middle of the grading structures is gradually narrowed toward both ends, so as to control the beam shape in the wideband in the longitudinal direction, thereby improving the symmetry of the feed pattern in all directions sex.

In an optional or preferred embodiment, the cross section of the second medium loading is cross-shaped, and the second medium loading includes four of the gradient structures arranged at equal angles.

In an optional or preferred embodiment, the second medium is loaded with a polycarbonate medium with a relative permittivity of 2.8.

In an optional or preferred embodiment, at least two grooves are provided, and the first medium loading includes a plurality of annular bodies whose diameters increase in sequence, and each annular body is installed in the matching groove. , each of the annular bodies is concentrically installed on the horn surface of the waveguide horn.

In an optional or preferred embodiment, the first medium is loaded with a polycarbonate medium with a relative permittivity of 2.8.

In an optional or preferred embodiment, two grooves are provided, and two annular bodies are provided, which are a first annular medium located on the inner ring and a second annular medium located on the outer ring, respectively.

In an optional or preferred embodiment, the inner peripheral surface and the upper end surface of the first annular medium are provided with metal plating layers, and the lower end surface, the outer peripheral surface, and the inner peripheral surface of the second annular medium are provided with Metal plating.

In an optional or preferred embodiment, the waveguide horn is a four-ridged waveguide, and the waveguide horn includes a horn body and four ridge pieces equiangularly installed inside the horn body.

Based on the above technical solution, the embodiments of the present invention have at least the following beneficial effects: in the above technical solution, by opening a groove on the waveguide horn and placing the first medium loading with a relative permittivity greater than 1, the first medium loading can be applied in the lateral direction. The shape of the broadband inner beam is controlled to form a feed structure of "corrugated horn + medium loading". Its working principle is the same as that of the traditional corrugated horn. It also changes the current distribution on the surface of the aperture, and then changes the electromagnetic wave distribution to control the beam width. effect. Because the relative permittivity loaded by the first medium is greater than 1, the stability of the E/H plane pattern of the feed can be improved, for example, the 10dB beam width of the feed can be controlled within a wider bandwidth at (2θ _m )±10 °, and the end-fire direction gain of the feed can also be controlled stably, and the size can be made smaller than that of the traditional corrugated horn, thereby realizing miniaturization and light weight. At the same time, the second medium is loaded in the longitudinal direction to control the beam shape of the broadband in the longitudinal direction, and the 10dB beam width of the E/H plane pattern of the feed can be adjusted from a huge difference to close to each other, which further improves the pattern of the feed. isotropic symmetry.

Description of drawings

Below in conjunction with accompanying drawing and embodiment, the present invention is further described;

1 is a perspective view of an embodiment of the present invention;

2 is a front view of an embodiment of the present invention;

3 is a cross-sectional view of an embodiment of the present invention;

4 is a top view of an embodiment of the present invention;

5 is a perspective view of a first medium loading in an embodiment of the present invention;

6 is a perspective view of a second medium loading in an embodiment of the present invention;

Fig. 7 is the S-parameter diagram of the simulation performance of the embodiment of the present invention;

FIG. 8 is an antenna end-fire directional gain diagram according to an embodiment of the present invention;

FIG. 9 is an E-plane directional diagram of an antenna according to an embodiment of the present invention;

10 is an H-plane directional diagram of an antenna according to an embodiment of the present invention;

11 is a feed pattern of a 10dB beam width according to an embodiment of the present invention;

12 is a schematic diagram of the directivity of a reflector antenna according to an embodiment of the present invention;

FIG. 13 is a schematic diagram of the aperture efficiency of a reflector antenna according to an embodiment of the present invention.

Detailed ways

This part will describe the specific embodiments of the present invention in detail, and the preferred embodiments of the present invention are shown in the accompanying drawings. Each technical feature and overall technical solution of the invention should not be construed as limiting the protection scope of the invention.

In the description of the present invention, it should be understood that the azimuth description, such as the azimuth or position relationship indicated by up, down, front, rear, left, right, etc., is based on the azimuth or position relationship shown in the drawings, only In order to facilitate the description of the present invention and simplify the description, it is not indicated or implied that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention.

In the description of the present invention, the meaning of several is one or more, the meaning of multiple is two or more, greater than, less than, exceeding, etc. are understood as not including this number, above, below, within, etc. are understood as including this number. If it is described that the first and the second are only for the purpose of distinguishing technical features, it cannot be understood as indicating or implying relative importance, or indicating the number of the indicated technical features or the order of the indicated technical features. relation.

In the description of the present invention, unless otherwise clearly defined, words such as setting, installation, connection should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

1 to 6 , a miniaturized broadband stabilized beam horn feed antenna includes a waveguide horn 10 and a second dielectric loading 30 . The waveguide horn 10 is a four-ridged waveguide, and the waveguide horn 10 includes a horn body 11 and four ridge pieces 12 equiangularly installed inside the horn body 11 . As shown in FIG. 3 , the waveguide horn 10 has a reflection cavity 13 and is located in the bottom of the horn body 11 .

Wherein, the horn surface of the waveguide horn 10 is provided with several grooves, and the grooves are installed with a first dielectric loading 20 to control the beam shape in the wideband in the lateral direction. The relative permittivity of the first dielectric loading 20 is greater than 1, In this embodiment, the first dielectric loading 20 adopts a polycarbonate dielectric with a relative dielectric constant of 2.8.

In one embodiment, there are at least two grooves, and the first medium loading 20 includes a plurality of annular bodies whose diameters increase in sequence, each annular body is installed in a matching groove, and each annular body is concentrically installed on the waveguide horn 10 horn faces. Specifically, two grooves are provided. As shown in FIG. 5 , two annular bodies are provided, which are a first annular medium 21 located on the inner ring and a second annular medium 22 located on the outer ring.

In addition, the inner peripheral surface and the inner edge of the upper end surface of the first annular medium 20 are provided with a metal plating layer 23, and the inner edge of the upper end surface of the first annular medium 20 refers to the partial area of the upper end surface close to the inner peripheral surface. Metal plating layers 23 are provided on the lower end surface, outer peripheral surface and inner peripheral surface of the ring medium. In this embodiment, the directions of the “upper end face” and the “lower end face” are referred to FIG. 5 to describe the structures of the first annular medium and the second annular medium, and should not be construed as a protection limitation of the present application.

It can be understood that, in the above technical solution, by opening a groove on the waveguide horn 10 and placing the first dielectric loading 20 with a relative permittivity greater than 1, the first dielectric loading 20 can control the beam shape in the wideband in the lateral direction. , forming a "corrugated horn + medium loading" feed structure, its working principle is the same as that of a traditional corrugated horn, and also by changing the current distribution on the surface of the aperture, and then changing the electromagnetic wave distribution, to achieve the effect of controlling the beam width. Because the relative permittivity loaded by the first medium is greater than 1, the stability of the E/H plane pattern of the feed can be improved, for example, the 10dB beam width of the feed can be controlled within a wider bandwidth at (2θ _m )±10 °, and the end-fire direction gain of the feed can also be controlled stably, and the size can be made smaller than that of the traditional corrugated horn, thereby realizing miniaturization and light weight.

As shown in FIG. 1 and FIG. 2 , the second dielectric loading 30 is installed at the aperture position of the waveguide horn 10 . The second dielectric loading 30 includes a plurality of gradation structures 31 , and the middle of the gradation structures 31 is gradually narrowed toward both ends, so that in the longitudinal direction Controls the beam shape within the broadband to improve the anisotropic symmetry of the feed pattern. Specifically, referring to FIG. 6 , the cross section of the second medium loading 30 is cross-shaped, and the second medium loading 30 includes four gradient structures 31 arranged at equal angles. The second dielectric loading 30 uses a polycarbonate dielectric with a relative permittivity of 2.8. The second medium is loaded in the longitudinal direction to control the beam shape in the broadband in the longitudinal direction, and the 10dB beam width of the E/H plane pattern of the feed can be adjusted from a huge difference to close to each other, which further improves the pattern of the feed in all directions. symmetry.

Through the combined effect of the first medium loading and the second medium loading, the beam width control in the broadband can be realized through comprehensive adjustment.

The technical solution of the present invention is described below by taking a miniaturized wide-reflector antenna feed source operating at 17.48-40.31 GHz with a four-ridged waveguide horn loaded as an example as an example. In addition, the radiation aperture design in the present invention is also applicable to the design of the reflector antenna feed source of other frequency bands, other shape apertures, and other different feeding modes.

Figure 7 shows the S-parameter diagram of the simulation performance. It can be seen that the feed antenna in this example can cover the frequency range of 17.48-40.31 GHz, which is greater than 79% of the relative bandwidth.

Figure 8 is the end-fire directional gain diagram of the feed antenna, and the in-band gain fluctuation is less than 1.7dBi. The corresponding gains of the upper and lower frequency bands are 8.91dBi@27.6GHz and 10.59dBi@40.31GHz respectively. As the frequency increases, it can be seen that the gain increases first, then decreases and then increases again, the fluctuation range is low, and the gain changes more smoothly with the frequency.

Figure 9 shows the E-plane pattern of the feed antenna at four frequency points of 18.5, 25.5, 32.5, and 39.5 GHz, and Figure 10 shows the feed antenna at four frequency points of 18.5, 25.5, 32.5, and 39.5 GHz. The H-plane orientation diagram. It can be seen that the patterns on the E and H planes are kept symmetrical. Moreover, it can be seen that the patterns of the frequency points of the E and H surfaces are very close in shape within the range of -10-0dB.

Figure 11 shows the feed pattern of the 10dB beamwidth. It can be seen that the 10dB beamwidth fluctuates within the range of 115°±10° in the entire near 80% relative bandwidth, and does not exceed this range. This also shows that the 10dB beamwidth of the feed antenna is controlled very stably.

Figure 12 shows the directivity of the feed antenna irradiated on the corresponding reflecting surface, the first side lobe is as low as -23.89dBi, and most of the side lobes are below -40dBi.

Fig. 13 shows the aperture efficiency of the feed antenna illuminating the corresponding reflecting surface, which is greater than 65% in the entire working bandwidth. It can be seen that the equivalent phase center of the feed antenna is stable, and there is no phenomenon that the equivalent phase center is shifted.

In the prior art, the conventional corrugated horn is to expand the horn surface in the lateral direction, thereby controlling the beam shape in the broadband. In the embodiment of the present invention, a structure of waveguide horn + first medium loading + second medium loading is adopted, the first medium loading controls the shape of the broadband inner beam in the lateral direction, and the second medium loading in the longitudinal direction controls the shape of the broadband inner beam Take control. In this way, the overall size of the feed antenna is smaller than that of the feed antenna in the existing corrugated horn solution. The invention solves the contradiction of realizing wide bandwidth in a small volume, and also makes the feed antenna have the characteristics of miniaturization and light weight, so that the feed antenna can be better widely used.

Although the traditional log-periodic antenna has a wide operating bandwidth, its working principle leads to a long current path and large loss, and the equivalent phase center of high frequency and low frequency has a large offset, making the log-periodic antenna impossible. To obtain high aperture efficiency, it is even impossible to obtain high aperture efficiency in a wide band. In the embodiment of the invention, the structure of waveguide horn + first medium loading + second medium loading is adopted, which can not only achieve stable control gain and stable beam width within a relative bandwidth of 79%, but also ensure the stability of the equivalent phase center. , achieving high aperture efficiency within a wide band.

The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned embodiments. Within the scope of knowledge possessed by those of ordinary skill in the technical field, various modifications can be made without departing from the purpose of the present invention. kind of change.

Claims (8)

1. A miniaturized broadband stabilized beam horn feed antenna, characterized in that: comprising: A waveguide horn, the horn surface of the waveguide horn is provided with a number of grooves, the grooves are installed with the first medium loading, so as to control the beam shape in the wideband in the lateral direction, and the first medium loading is relatively The dielectric constant is greater than 1, and the first dielectric is loaded with a metal coating; and The second medium loading, the second medium loading is installed at the aperture position of the waveguide horn, and the second medium loading includes a plurality of gradation structures, and the middle of the gradation structures is gradually reduced toward both ends, so as to meet the longitudinal direction. The beam shape is controlled within the broadband to improve the anisotropic symmetry of the feed pattern. 2 . The miniaturized broadband stabilized beam horn feed antenna according to claim 1 , wherein the cross-section of the second medium loading is cross-shaped, and the second medium loading comprises four equiangularly arranged horn feed antennas. 3 . Describe the gradient structure. 3 . The miniaturized broadband stabilized beam horn feed antenna according to claim 2 , wherein the second medium is loaded with a polycarbonate medium with a relative permittivity of 2.8. 4 . 4 . The miniaturized broadband stabilized beam horn feed antenna according to claim 1 , wherein at least two grooves are provided, and the first medium loading comprises a plurality of annular bodies whose diameters increase in sequence, and each The annular bodies are installed in the matching grooves, and each annular body is concentrically installed on the horn surface of the waveguide horn. 5 . The miniaturized broadband stabilized beam horn feed antenna according to claim 4 , wherein the first medium is loaded with a polycarbonate medium with a relative permittivity of 2.8. 6 . 6 . The miniaturized broadband stabilized beam horn feed antenna according to claim 4 , wherein two of the grooves are provided, and two of the annular bodies are provided, which are respectively the first annular medium located in the inner ring. 7 . and a second annular medium located on the outer ring. 7 . The miniaturized broadband stabilized beam horn feed antenna according to claim 6 , wherein the inner peripheral surface and the inner edge of the upper end surface of the first annular medium are provided with metal coatings, and the second annular medium is provided with a metal coating. 8 . The lower end surface, the outer peripheral surface and the inner peripheral surface of the medium are provided with metal plating layers. 8. The miniaturized broadband stabilized beam horn feed antenna according to any one of claims 1 to 7, wherein the waveguide horn is a four-ridged waveguide, and the waveguide horn comprises a horn body and is equiangularly mounted on the horn. Describe the four ridges inside the speaker body.

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