Low-profile broadband opening horn antenna

Abstract

The low-profile broadband open horn antenna comprises a rectangular metal waveguide, the top and the bottom of the rectangular metal waveguide are each provided with a V-shaped air cavity which faces the wide side of a rectangle and is connected with an external free space, and a V-shaped opening which faces the wide side of the rectangle and is connected with the external free space is formed in each V-shaped air cavity; the metal wall of the V-shaped opening is removed; and the coaxial feeder line longitudinally penetrates through the rectangular metal waveguide, and the top of the coaxial feeder line is connected with metal between the end point of the V-shaped air cavity and the end point of the V-shaped opening. The cross polarization suppression degree of electromagnetic waves passing through the rectangular metal waveguide is high; meanwhile, the width of the V-shaped opening is continuously expanded along the propagation direction, electromagnetic waves propagated in the structure of the V-shaped opening are TE10 modes in the metal waveguide, and the electromagnetic waves in the modes have the characteristic of high gain during radiation, so that the antenna has the characteristic of high gain radiation.

Description

Technical Field

[0001] This invention relates to the field of microwave antenna technology, and more particularly to a low-profile broadband open-aperture horn antenna. Background Technology

[0002] In the design and application of broadband high-gain antennas, to achieve key performance indicators such as low cross-polarization, ultra-wideband, and high gain, traditional broadband horn antennas typically require an aperture size matching the half-vacuum wavelength corresponding to the lowest operating frequency. This results in a relatively high overall antenna profile, making it difficult to meet the compactness and integration requirements of modern communication equipment. Therefore, how to achieve ultra-wideband high-gain radiation and ensure a high level of cross-polarization suppression through a low-profile structure while maintaining superior electrical performance has become a challenge with significant research value and practical application prospects in the antenna field.

[0003] Some existing technologies combine parabolic waveguides with rectangular waveguides, placing a metal ridge in the middle of the rectangular waveguide and feeding it via a coaxial line. While this design achieves end-fire characteristics and broadband performance to some extent, it still suffers from the following practical drawbacks: First, the existing technology employs an open upper-span design, with energy radiation primarily directed into free space, lacking a closed waveguide structure. This makes it difficult to integrate with planar circuits and susceptible to external interference. Second, while the metal ridge structure helps achieve impedance matching and broadband characteristics, its high fabrication complexity and stringent manufacturing precision requirements hinder mass production and cost control. Furthermore, because its overall structure relies on three-dimensional metal processing, it cannot be implemented using printed circuit board (PCB) technology, limiting its integration into standard communication modules and increasing overall structural complexity and manufacturing costs.

[0004] Therefore, there is an urgent need for a new antenna structure that can combine planar integration technologies such as substrate integrated waveguide (SIW), adopt standard PCB processes, and have low profile, high cross-polarization suppression and ultra-wideband high gain performance, in order to overcome the limitations of existing open structures and complex feeding methods. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a low-profile broadband open horn antenna.

[0006] The objective of this invention is achieved through the following technical solution: A first aspect of the present invention provides a low-profile broadband open-aperture horn antenna, comprising: A rectangular metal waveguide has V-shaped air cavities at its top and bottom that connect to the external free space and face the wide side of the rectangle. Inside the V-shaped air cavities, there are V-shaped openings that connect to the external free space and face the wide side of the rectangle. The metal walls of the V-shaped openings are removed. A coaxial feed line extends longitudinally through the rectangular metal waveguide arrangement, with the top of the coaxial feed line connected to the metal connection between the V-shaped air cavity endpoint and the V-shaped opening endpoint.

[0007] Furthermore, the top of the coaxial feeder is a circular feeder disk.

[0008] Furthermore, the opening width of the V-shaped air cavity in the rectangular metal waveguide is 1.5 times the vacuum wavelength corresponding to the lowest operating frequency; the height of the rectangular metal waveguide is 0.5 times the vacuum wavelength corresponding to the lowest operating frequency.

[0009] Furthermore, the width of the V-shaped opening is 1.5 times the vacuum wavelength corresponding to the highest operating frequency; the height of the V-shaped opening is approximately 0.25 times the vacuum wavelength corresponding to the lowest operating frequency.

[0010] Furthermore, both the V-shaped air cavity and the V-shaped opening are symmetrical about the x-axis.

[0011] The beneficial effects of this invention are: In an exemplary embodiment of the present invention, the electromagnetic waves passing through the rectangular metal waveguide exhibit high cross-polarization suppression. Simultaneously, the width of the V-shaped opening continuously expands along the propagation direction, and the electromagnetic waves propagating within the V-shaped opening are all TE10 modes in the metal waveguide. These electromagnetic waves exhibit high gain characteristics during radiation, thus the antenna possesses high-gain radiation characteristics. Compared to the prior art's open upper half-space design and the inability to utilize printed circuit board (PCB) technology for three-dimensional metal processing, this exemplary embodiment employs a substrate integrated waveguide (SIW) design, i.e., designed within a closed upper and lower space, using a circular patch probe for feeding. This can be achieved using PCB technology, resulting in a simple process, simple structure, and easy fabrication. Attached Figure Description

[0012] Figure 1 A cross-sectional view of a low-profile broadband open-aperture horn antenna provided as an exemplary embodiment of the present invention. Figure 2 A top view of a low-profile broadband open-aperture horn antenna provided as an exemplary embodiment of the present invention; Figure 3 S-parameter diagram of a low-profile broadband open-aperture horn antenna provided as an exemplary embodiment of the present invention; Figure 4 Vertical polarization pattern of a low-profile broadband open-aperture horn antenna provided as an exemplary embodiment of the present invention; Figure 5 The main polarization and cross-polarization patterns of a low-profile broadband open-aperture horn antenna provided as an exemplary embodiment of the present invention. Detailed Implementation

[0013] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0014] In the description of this invention, it should be noted that the directions or positional relationships indicated by terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0015] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0016] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0017] See Figure 1 and Figure 2 , Figure 1 and Figure 2 Cross-sectional and top views of a low-profile broadband open-aperture horn antenna provided in an exemplary embodiment of the present invention are shown, including: A rectangular metal waveguide 1 has V-shaped air cavities 2 at its top and bottom that connect to the external free space and face the wide side of the rectangle. A V-shaped opening 3 is formed inside the V-shaped air cavity 2 that connects to the external free space and faces the wide side of the rectangle. The metal wall of the V-shaped opening 3 is removed. A coaxial feed line 4 is arranged longitudinally through the rectangular metal waveguide 1, with a metal connection between the top of the coaxial feed line 4 and the end points of the V-shaped air cavity 2 and the V-shaped opening 3.

[0018] Specifically, in this exemplary embodiment, the size of the rectangular metal waveguide 1 is approximately 1.5λ. low ×0.5λ low ×0.15λ low , where λ low The minimum operating frequency band of the vacuum wavelength is represented by a V-shaped air cavity 2 formed within the rectangular metal waveguide 1. The opening of the V-shaped air cavity 2 is connected to the external free space, and the opening width is ( W The length of the cuboid is shorter than its long side, and the difference between the two is 2 times the thickness of the metal wall, which can be any value. The depth ( L The shorter side of the cuboid is 2 times the thickness of the metal wall. H The thickness is smaller than that of a cuboid, and all walls except the opening of the V-shaped air cavity 2 are thin metal walls. Then, V-shaped openings 3 are made on the front and back of the V-shaped air cavity 2. The metal walls at the top and bottom of the V-shaped openings 3 are removed and the side walls are not connected, so as to radiate electromagnetic waves of different frequency bands.

[0019] At the end of the V-shaped opening 3 ( O 1) and V-shaped air cavity 2 ( O 0) Select a feed point between the endpoints, the distance of which from the endpoint of the V-shaped opening 3 is... d x (Unit: mm) In one preferred exemplary embodiment, the coaxial feeder 4 feeds electromagnetic waves through a metal disk structure 41.

[0020] Specifically, in this exemplary embodiment, electromagnetic energy is coupled into the rectangular metal waveguide 1 through the coaxial feed line 4 (the metal disk structure 41 of the coaxial feed line 4). The energy propagates on the rectangular metal waveguide 1 and begins to radiate through the opening gap of the V-shaped opening 3 after encountering an opening. As the opening gap gradually widens, the broadband energy transmitted to the metal opening horn can be effectively radiated out.

[0021] It should be noted that the rectangular metal waveguide 1 is fed by a coaxial feed line 4 with a metal disk structure 41. The energy is coupled from the coaxial electromagnetic wave to the metal waveguide through the metal disk structure 41 and converted into a waveguide propagation mode. The electromagnetic wave in the rectangular metal waveguide 1 radiates ultra-wideband energy into free space through the V-shaped opening 3, achieving ultra-wideband radiation. Since the electromagnetic wave propagating in the rectangular metal waveguide 1 has extremely high cross-polarization suppression, the electromagnetic wave passing through the rectangular metal waveguide 1 has high cross-polarization suppression. At the same time, the width of the V-shaped opening 3 continuously expands along the propagation direction, and the electromagnetic wave propagating in the structure of the V-shaped opening 3 is all in the TE10 mode of the metal waveguide. This mode of electromagnetic wave radiation has high gain characteristics, so the antenna has high gain radiation characteristics.

[0022] Compared to existing technologies that employ an open upper space design and cannot be implemented using printed circuit board (PCB) technology for three-dimensional metal processing, this exemplary implementation achieves antenna radiation by adjusting the metal waveguide structure and openings within a closed upper and lower metal space. The SIW structure is enclosed by two layers of PCB metal and the waveguide structure is adjusted through metallized vias. Therefore, the antenna in this example can be implemented using substrate integrated waveguide SIW, i.e., designed in a closed upper and lower space, and fed with a circular patch probe. All cavities, openings, and patch feeding can be fabricated using PCB technology, resulting in a simple process, simple structure, and easy fabrication.

[0023] More preferably, in one exemplary embodiment, the opening width of the V-shaped air cavity in the rectangular metal waveguide is 1.5 times the vacuum wavelength corresponding to the lowest operating frequency; the height of the rectangular metal waveguide is 0.5 times the vacuum wavelength corresponding to the lowest operating frequency. More preferably, in one exemplary embodiment, the width of the V-shaped opening is 1.5 times the vacuum wavelength corresponding to the highest operating frequency; the height of the V-shaped opening is approximately 0.25 times the vacuum wavelength corresponding to the lowest operating frequency. More preferably, in one exemplary embodiment, for ease of design and manufacturing, both the V-shaped air cavity and the V-shaped opening are symmetrical about the x-axis.

[0024] In a specific exemplary embodiment, the open-aperture horn antenna can radiate vertically polarized electromagnetic waves over an ultra-wideband range, and its actual normal gain is greater than 5 dBi in the operating frequency band. The open-aperture horn antenna can radiate electromagnetic waves over an ultra-wideband range with a relative bandwidth of approximately 55.6%. The normal radiation cross-polarization suppression of the open-aperture horn antenna is greater than 40 dBc in the operating frequency band. The open-aperture horn antenna has a profile of only 10 mm, exhibiting low profile characteristics.

[0025] The antenna is manufactured using a metal structure, resulting in low cost and good stability. It can achieve broadband high-gain radiation from 4.6 GHz to 8 GHz and can be used in modern wireless communication systems and other fields.

[0026] By appropriately adjusting the feed positions of the rectangular metal waveguide 1, the V-shaped air cavity 2, the V-shaped opening 3, and the coaxial feed line 4, radiation can be achieved over a wide bandwidth. Figure 3 The S-parameters of this antenna are given; they are all less than -10 dB from 4.6 GHz to 8 GHz. This low-profile broadband open-aperture horn antenna radiates high-gain vertically polarized electromagnetic waves. Figure 4 The vertical polarization pattern of the antenna in the H-plane is given. Figure 5 The vertical and horizontal polarization patterns of the antenna in the H-plane are given. Figure 4 At an angle of 0°, the gain of all radiation frequencies is greater than 5 dBi. Due to the high polarization purity of the electromagnetic waves inside the waveguide, the radiated electromagnetic waves exhibit high cross-polarization suppression. Figure 5 When the radiation angle is 0, the main polarization gain is more than 40dB greater than the cross-polarization gain. Therefore, the normal cross-polarization suppression of this antenna can reach 40dBc.

[0027] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A low profile broadband open horn antenna, characterized by: The utility model relates to a rectangular metal waveguide, a coaxial feeder wire and a V-shaped air cavity. The utility model discloses a rectangular metal waveguide, a coaxial feeder wire and a V-shaped air cavity. The utility model discloses a rectangular metal waveguide, a coaxial feeder wire and a V-shaped air cavity.

2. The low profile broadband aperture horn antenna of claim 1, wherein: The utility model discloses a rectangular metal waveguide, a coaxial feeder wire and a V-shaped air cavity.

3. The low profile broadband aperture-coupled horn antenna of claim 1, wherein: The utility model discloses a rectangular metal waveguide, a coaxial feeder wire and a V-shaped air cavity.

4. The low profile broadband aperture-coupled horn antenna of claim 1, wherein: The utility model discloses a rectangular metal waveguide, a coaxial feeder wire and a V-shaped air cavity.

5. The low profile broadband aperture-corn antenna of claim 1, wherein: ​

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