Forward-backward switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna

Abstract

The present invention discloses a forward and backward switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna, which belongs to the field of radio frequency communication technology. Port one is extended from the outer end of the copper clad layer, and port two is extended from the outer end of the SIW-based waveguide transmission line. The dielectric substrate is arranged on the side of the upper surface stepped floor away from the partial reflective surface of the upper surface; two microstrip lines are connected to the two ends of the copper clad layer respectively, and a gap is opened in the copper clad layer. There are multiple metal through holes on the copper clad layer, which are arranged around the circumference of the copper clad area; each metal through hole connects the copper clad layer and the metal stratum; six hollow rings are etched inside the upper surface stepped floor and the upper part of the lower surface stepped floor, and the six hollow rings are arranged in a stepped manner, and four hollow rings are etched inside the stepped reflection ring of the upper surface stepped floor and the lower surface stepped floor, and the four hollow rings are arranged in a stepped manner.

Description

Technical Field

[0001] The invention relates to a forward and backward switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna, belonging to the technical field of radio frequency communications. Background Art

[0002] In millimeter-wave communication systems, the 30 GHz frequency band has become the core frequency band for achieving high-speed uplink and downlink transmission due to its large bandwidth characteristics. The uplink needs to achieve wide-area uniform coverage through a horizontally polarized flat-top beam to support multi-terminal access, while the downlink relies on a vertically polarized high-gain narrow beam to improve directional transmission efficiency.

[0003] Fabry-Perot (FP) cavity antennas are considered as a candidate for achieving such dual-function radiation due to their high directivity, low profile and multi-beam steering potential.

[0004] However, existing FP cavity-based designs face significant challenges in simultaneously meeting beamforming flexibility and polarization isolation performance.

[0005] Traditional FP cavity antennas usually use a single-layer partially reflecting surface (PRS) and a ground layer to form a resonant cavity. Beam focusing or deflection is achieved by adjusting the phase gradient of the PRS unit. However, its symmetrical cavity structure causes the polarization mode and radiation pattern of the uplink and downlink beams to be highly coupled.

[0006] In addition, to achieve polarization diversity, conventional FP cavities often use orthogonal dual feeds or polarization-rotated metasurfaces. Although such designs can separate polarization channels, the equalized field distribution required for the flat-top beam (amplitude fluctuation <±1.5dB) and the sharp cutoff characteristics of the high-gain beam (sidelobes <-20dB) cannot be taken into account at the same time due to the conflict in cavity mode excitation.

[0007] Therefore, how to achieve efficient collaborative radiation of horizontally polarized flat-top beams and vertically polarized high-gain beams through innovative structural design based on the FP cavity architecture, and simultaneously resolve the contradiction between beamforming freedom, polarization isolation and high-frequency efficiency, has become a core issue that urgently needs to be broken through in this technical field.

[0008] In summary, realizing a front-to-back switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna is of great practical significance for meeting the communication system's requirements for multi-beamforming and dual-polarization isolation, and can effectively respond to the challenges posed by future higher-performance communication terminals to antenna equipment. Summary of the Invention

[0009] The main purpose of the present invention is to provide a forward and backward switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna.

[0010] The purpose of the present invention can be achieved by adopting the following technical solutions:

[0011] A forward and backward switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna comprises an upper surface partial reflective surface and a lower surface partial reflective surface, wherein the lower surface partial reflective surface is provided with an upper surface stepped floor, a dielectric substrate, a copper cladding layer, a lower surface stepped floor and a SIW-based waveguide transmission line from top to bottom;

[0012] The outer end of the copper cladding layer extends with a port 1, and the outer end of the siw-based waveguide transmission line extends with a port 2;

[0013] The dielectric substrate is arranged on a side of the upper stepped floor away from the upper partial reflective surface.

[0014] Two microstrip lines are connected to both ends of the copper clad layer respectively. A gap is opened in the copper clad layer. There are multiple metal through holes on the copper clad layer, which are arranged around the copper clad area. Each metal through hole connects the copper clad layer and the metal ground layer.

[0015] Six hollow rings are etched inside the upper surface stepped floor and the upper part of the lower surface stepped floor, and the six hollow rings are arranged in a stepped manner. Four hollow rings are etched inside the upper surface stepped floor and the lower half stepped reflection ring of the lower surface stepped floor, and the four hollow rings are arranged in a stepped manner.

[0016] The edges of the upper and lower reflective surfaces are also preset with multiple mounting portions;

[0017] The forward and backward switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna also includes:

[0018] A plurality of metal support columns, one end of each metal support column is fixed to the dielectric substrate, and the other end of each metal support column passes through the upper surface stepped floor and the lower surface stepped floor and is fixed to the mounting portion.

[0019] Preferably, the upper and lower parts of the stepped floor have stepped surfaces, and the lower surface of the stepped floor has stepped surfaces. In the upper part of the stepped floor, the radius of the outer ring of the stepped reflective ring decreases from bottom to top, while the radius of the inner ring remains unchanged, so as to form a flat top.

[0020] In the lower part, the lower surface of the stepped floor has an increasing radius from top to bottom.

[0021] Preferably, the upper surface stepped floor and the lower surface stepped floor of the upper and lower parts have similar changing trends of the outer circle radii of the upper and lower stepped reflection rings.

[0022] Preferably, the dielectric substrate is a plate with a dielectric constant of 2.2, and the height and width of siw are respectively set to 0.114 times the wavelength and 0.64 times the wavelength of the antenna center operating frequency.

[0023] Metal layers are printed on the upper and lower surfaces of the dielectric substrate.

[0024] Preferably, two rectangular open feeding slots are respectively etched on the upper and lower surfaces of the center of the dielectric substrate, and the two rectangular U-shaped open feeding slots are perpendicular to each other and together constitute the radiation aperture of the antenna.

[0025] Preferably, the two rectangular transmission lines of the SIW-based waveguide transmission lines are composed of a series of metal through holes arranged at a certain interval, and the SIW-based waveguide transmission lines are constructed inside the dielectric substrate.

[0026] Beneficial technical effects of the present invention:

[0027] The present invention provides a high-gain flat-top dual-mode switching Fabry-Perot cavity antenna that can be switched forward and backward. Figure 1 、 Figure 2 、 Figure 3 and Figure 4 As shown, it includes an upper surface partial reflective surface and a lower surface partial reflective surface, and the lower surface partial reflective surface is distributed from top to bottom with an upper surface stepped floor, a dielectric substrate, a copper clad layer, a lower surface stepped floor 8 and a waveguide transmission line based on SIW;

[0028] The outer end of the copper cladding layer extends with a port 1, and the outer end of the siw-based waveguide transmission line 9 extends with a port 2;

[0029] The dielectric base 4 is arranged on a side of the upper surface stepped floor away from the upper surface partial reflective surface 1 .

[0030] Two microstrip lines are connected to both ends of the copper clad layer, a gap is opened in the copper clad layer, and a plurality of metal through holes are provided on the copper clad layer. When the diameter of the metal through holes is between 0.3 mm and 0.5 mm, the impedance matching performance of the antenna is optimal;

[0031] For example, when the metal through-hole diameter is set to 0.4mm, the parameter can be further reduced by 1-2dB within the working frequency band, so that the signal transmission efficiency of the antenna is significantly improved. Each metal through-hole is arranged around the copper clad area, and connects the copper clad layer and the metal ground layer.

[0032] Six hollow rings are etched inside the upper surface stepped floor and the upper part of the lower surface stepped floor, and the six hollow rings are arranged in a stepped manner. Four hollow rings are etched inside the stepped reflective ring of the upper surface stepped floor and the lower surface stepped floor, and the four hollow rings are arranged in a stepped manner, with 2-3 layers of hollow rings added, and the size of each layer of hollow rings decreases according to a certain proportional coefficient, such as a proportional coefficient of 0.8-0.9;

[0033] This allows for more precise control of the floor's electromagnetic properties, enhancing the reflection and refraction of electromagnetic waves. Simulations and comparisons show that increasing the number of hollow ring layers and optimizing the size gradient can increase the antenna's gain by 0.5-1dB when radiating upward and 0.8-1.2dB when radiating downward, effectively improving the antenna's radiation performance.

[0034] The edges of the upper and lower reflective surfaces are also preset with multiple mounting portions. The width and height of the integrated waveguide siw and the dielectric constant of the substrate are related to the working frequency band of the antenna. In order to achieve the characteristics of both low profile and broadband, the dielectric substrate of this article adopts a plate with a dielectric constant of 2.2. The height and width of siw are set to 0.114 times the wavelength and 0.64 times the wavelength of the antenna center operating frequency, respectively. Figure 5 As shown in the two figures, the S parameters, gain and axial ratio curves obtained by HFSS simulation software are shown. It can be seen from the figure that the working frequency band (S 11 <-10dB) is 25GHz-34GHz;

[0035] The antenna's axial ratio can be reduced by 0.5-1dB within the entire operating frequency band, and the cross-polarization discrimination (XPD) is increased by 3-5dB, making the antenna's circular polarization performance more stable and excellent, effectively reducing signal interference and loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a schematic diagram of the overall three-dimensional structure of a preferred embodiment of a forward-backward switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna according to the present invention;

[0037] Figure 2 It is an exploded side view of the overall three-dimensional structure of a preferred embodiment of the forward and backward switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna according to the present invention;

[0038] Figure 3 It is an exploded side elevation view of the overall three-dimensional structure of a preferred embodiment of the forward and backward switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna according to the present invention;

[0039] Figure 4 A schematic diagram of a waveguide transmission line structure based on SIW according to a preferred embodiment of the forward and backward switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna of the present invention;

[0040] Figure 5 The normalized radiation pattern of a preferred embodiment of the forward and backward switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna according to the present invention at 30 GHz;

[0041] Figure 6 A preferred embodiment of the forward and backward switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna according to the present invention;

[0042] Figure 7 The present invention is a preferred embodiment of the forward and backward switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna.

[0043] In the figure: 1. Partially reflecting surface on the upper surface; 2. Partially reflecting surface on the lower surface; 3. Stepped floor on the upper surface; 4. Dielectric substrate; 5. Copper cladding; 6. Port one; 7. Port two; 8. Stepped floor on the lower surface; 9. SIW-based waveguide transmission line; 10. Feeding slot. DETAILED DESCRIPTION

[0044] In order to make the technical solution of the present invention more clear and specific to those skilled in the art, the present invention is further described in detail below with reference to embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0045] To make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0046] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely represents some embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0047] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features and technical solutions therein may be combined with each other.

[0048] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not require further definition or explanation in subsequent drawings.

[0049] In the description of the present invention, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or the orientations or positional relationships in which the inventive product is typically placed when in use, or the orientations or positional relationships commonly understood by those skilled in the art. Such terms are intended solely to facilitate the description of the present invention and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" and the like are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0050] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein elements marked with the same reference numerals indicate that they are the same or similar elements.

[0051] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0052] In the description of the present invention, it should be noted that the terms used to indicate orientation, such as "bottom", "top", "above", "below", "length", "width" and the like, are only used to qualitatively describe the position of the component according to the image shown in the figure, and do not mean that the component must be in a specific position. Therefore, it should not be understood as a limitation of the present invention.

[0053] In the embodiments of the present invention, unless otherwise specified, terms such as "connection" and "support" may be understood in a broad sense.

[0054] For example, the connection method can be welding or fixing with screws, or it can be detachable; the support can use support columns made of different materials such as foam or resin to support the dielectric plate.

[0055] Specific operations can be handled in different ways according to the processing design

[0056] Example 1: Figure 1 、 Figure 2 、 Figure 3 and Figure 4 As shown, this embodiment proposes a forward and backward switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna, comprising an upper surface partial reflective surface 1 and a lower surface partial reflective surface 2, on which the upper surface stepped floor 3, a dielectric substrate 4, a copper cladding layer 5, a lower surface stepped floor 8, a SIW-based waveguide transmission line 9, and an open feeding slot 10 are distributed from top to bottom;

[0057] The outer end of the copper cladding layer 5 extends to have a port 1 6, and the outer end of the siw-based waveguide transmission line 9 extends to have a port 2 7;

[0058] The dielectric substrate 4 is arranged on a side of the upper stepped floor 3 away from the upper partial reflective surface 1 , and an open feeding slot 10 is provided on an outer ring of the axis of the dielectric substrate 4 .

[0059] Two microstrip lines are connected to the two ends of the copper clad layer 5, and a gap is opened in the copper clad layer 5. There are multiple metal through holes on the copper clad layer 5. When the diameter of the metal through holes is between 0.3mm and 0.5mm, the impedance matching performance of the antenna is optimal.

[0060] For example, when the diameter of the metal through hole is set to 0.4mm, the parameter can be further reduced by 1-2dB within the working frequency band, so that the signal transmission efficiency of the antenna is significantly improved. Each metal through hole is arranged around the copper clad area, and connects the copper clad layer 5 and the metal ground layer.

[0061] Six hollow rings are etched inside the upper half of the stepped floor 3 on the upper surface and the stepped floor 8 on the lower surface. The six hollow rings are arranged in a stepped manner. Four hollow rings are etched inside the stepped reflective rings on the upper surface and the stepped floor 3 on the lower surface. The four hollow rings are arranged in a stepped manner, and 2-3 layers of hollow rings are added. The size of each layer of hollow rings decreases according to a certain proportional coefficient, such as a proportional coefficient of 0.8-0.9.

[0062] This allows for more precise control of the floor's electromagnetic properties, enhancing the reflection and refraction of electromagnetic waves. Simulations and comparisons show that increasing the number of hollow ring layers and optimizing the size gradient can increase the antenna's gain by 0.5-1dB when radiating upward and 0.8-1.2dB when radiating downward, effectively improving the antenna's radiation performance.

[0063] The edges of the upper surface partial reflective surface 1 and the lower surface partial reflective surface 2 are also preset with multiple mounting parts. The width and height of the integrated waveguide siw and the dielectric constant of the substrate are related to the working frequency band of the antenna. In order to achieve the characteristics of both low profile and broadband, the dielectric substrate of this article adopts a plate with a dielectric constant of 2.2. The height and width of siw are set to 0.114 times the wavelength and 0.64 times the wavelength of the antenna center operating frequency, respectively. Figure 5 As shown in the two figures, the S parameters, gain and axial ratio curves obtained by HFSS simulation software are shown. It can be seen from the figure that the working frequency band (S 11 <-10dB) is 25GHz-34GHz;

[0064] The antenna's axial ratio can be reduced by 0.5-1dB within the entire operating frequency band, and the cross-polarization discrimination (XPD) is increased by 3-5dB, making the antenna's circular polarization performance more stable and excellent, effectively reducing signal interference and loss.

[0065] Metal layers are printed on the upper and lower surfaces of the dielectric substrate.

[0066] The two rectangular opening slots are respectively etched on the upper and lower surfaces of the center of the dielectric substrate. The two rectangular opening slots are perpendicular to each other and together constitute the radiation aperture of the antenna.

[0067] The two SIW-based rectangular transmission lines of the upper surface partial reflection surface 1 and the lower surface partial reflection surface 2 are composed of a series of metal through holes arranged at a certain interval and are constructed inside the dielectric substrate.

[0068] Example 2: Two SIW-based rectangular transmission lines extend from the left and right sides of the dielectric substrate toward the center of the antenna to the two rectangular openings, and the width of the transmission lines at the openings is expanded to surround the rectangular openings.

[0069] Two matching ends are located at the ends of the SIW-based rectangular transmission line, and each matching end is formed by a row of metal through-holes.

[0070] The two matching ends at the two rectangular opening gaps play a role in improving impedance matching, and the impedance matching can be adjusted by adjusting the length and the through-hole spacing.

[0071] Two feeding ports of the SIW-based rectangular transmission line are connected to the two transmission lines respectively and are located at the left and right ends of the dielectric substrate.

[0072] The two partial reflective surfaces of the upper surface partial reflective surface 1 and the lower surface partial reflective surface 2 are distributed above and below the rectangular gap, which is approximately 1 times the wavelength. Figure 6-7 As shown, these two figures are the upward and downward radiation patterns of this embodiment at 30 GHz from top to bottom.

[0073] from Figure 6 and 7 As can be seen from the figure, the antenna has a flat-top beam in the upward radiation and a high-gain narrow beam in the downward radiation. The antenna produces a stable radiation pattern within the operating frequency band.

[0074] From the above test results, it can be seen that the front-to-back switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna proposed in the present invention realizes upper and lower different beam radiation with stable radiation pattern and low cross-polarization level performance.

[0075] The embodiment described above is only one of the specific implementation methods selected after optimization in the present invention. Any modifications or changes made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

[0076] The above is only a further embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes based on the technical solutions and concepts of the present invention within the scope disclosed by the present invention, which fall within the scope of protection of the present invention.

Claims

1. A high-gain, flat-top, dual-mode Fabry-Perot cavity antenna with forward and backward switching capabilities, characterized by: The invention comprises an upper surface partial reflection surface (1) and a lower surface partial reflection surface (2), wherein the lower surface partial reflection surface (2) is provided with an upper surface stepped floor (3), a dielectric substrate (4), a copper cladding layer (5), a lower surface stepped floor (8) and a SIW-based waveguide transmission line (9) from top to bottom; The outer end of the copper cladding layer (5) is extended with a port one (6), and the outer end of the SIW-based waveguide transmission line (9) is extended with a port two (7); The dielectric substrate (4) is arranged on a side of the upper surface stepped floor (3) away from the upper surface partial reflection surface (1); Six hollow rings are etched inside the upper half of the stepped floor (3) and the lower half of the stepped floor (8), and the six hollow rings are arranged in a stepped manner. Four hollow rings are etched inside the lower half of the stepped reflection ring of the stepped floor (3) and the lower half of the stepped floor (8), and the four hollow rings are arranged in a stepped manner. The dielectric substrate (4) adopts a plate with a dielectric constant of 2.2, and the height and width of the siw are respectively set to 0.114 times the wavelength and 0.64 times the wavelength of the antenna center operating frequency.

2. The forward and backward switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna according to claim 1, characterized in that: Two microstrip lines are connected to the two ends of the copper clad layer (5), a gap is opened in the copper clad layer (5), and a plurality of metal through holes are arranged on the copper clad layer (5) around the circumference of the copper clad area, and each metal through hole connects the copper clad layer (5) and the metal ground layer.

3. The forward and backward switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna according to claim 2, characterized in that: A plurality of mounting portions are also preset on the edges of the upper surface partial reflective surface (1) and the lower surface partial reflective surface (2); The forward and backward switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna also includes: A plurality of metal support columns, one end of each metal support column is fixed to the dielectric base plate (4), and the other end of each metal support column passes through the upper surface stepped floor (3) and the lower surface stepped floor (8) and is fixed to the mounting portion.

4. The forward and backward switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna according to claim 3, characterized in that: The upper and lower parts are a stepped floor (3) on the upper surface and a stepped floor (8) on the lower surface. In the stepped floor (3) on the upper surface, the radius of the outer ring of the stepped reflection ring decreases from bottom to top, while the radius of the inner ring remains unchanged to form a flat top. In the lower half, the lower surface of the stepped floor (8) is provided, and the inner and outer circle radii of the lower surface of the stepped floor (8) increase from top to bottom.

5. The forward and backward switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna according to claim 4, characterized in that: Metal layers are printed on the upper and lower surfaces of the dielectric substrate (4).

6. The forward and backward switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna according to claim 5, characterized in that: Two rectangular open feeding slots (10) are respectively etched on the upper and lower surfaces of the center of the dielectric substrate (4); the two rectangular open feeding slots (10) are perpendicular to each other and together constitute the radiation aperture of the antenna.

7. The forward and backward switchable high-gain flat-top dual-mode switching Fabry-Perot cavity antenna according to claim 1, characterized in that: Two rectangular transmission lines of the SIW-based waveguide transmission line (9) are composed of a series of metal through holes arranged at a certain interval, and the SIW-based waveguide transmission line (9) is constructed inside the dielectric substrate (4).

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