A high-isolation, low-profile broadband base station antenna, control method, and application

Abstract

The present invention belongs to the field of communications technology and discloses a high-isolation, low-profile, broadband base station antenna, a control method, and applications. The high-isolation, low-profile, broadband base station antenna consists of two dielectric substrates, a circular patch, a ground plane, and a substrate-integrated waveguide. The upper and lower dielectric substrates are each covered with a circular patch on the front, and a substrate-integrated waveguide is provided on the underside of the lower dielectric substrate. The upper surface of the substrate-integrated waveguide is grounded to the ground plane, and the lower surface of the substrate-integrated waveguide is composed of two microstrip feeds. The present invention solves the problems of low profile, broadband, and high isolation for base station antennas. The unit antenna has a bandwidth of less than 2 within the range of 2.3-2.70 GHz, and the isolation within the frequency band reaches below 32 dB. The antenna has excellent performance, a simple structure, and is easy to process, install, and conform to the carrier. The antenna unit has a cross-sectional height of only 0.103λ0, and the planar dimensions are 0.425λ0×0.425λ0.

Description

Technical Field

[0001] The present invention belongs to the field of communication technology, and in particular relates to a high-isolation, low-profile broadband base station antenna, a control method and an application thereof. Background Art

[0002] Currently, conventional communication methods often fail to meet the demands of sudden, large-scale natural disasters and public emergencies. In particular, after a major disaster, damage to base stations can significantly reduce communication capabilities, even leading to interruptions and paralysis. Airborne communication platforms offer an excellent means of integrated air-ground emergency communication. By adjusting the platform's altitude, communication distances can be extended to several kilometers or even tens of kilometers, expanding coverage. Furthermore, aerial platforms offer convenient and flexible networking, making them particularly useful in challenging environments such as mountainous areas and scattered islands. Antennas, as core components of base stations, should possess a small footprint, be easy to install, have low power consumption, and achieve high gain. These characteristics significantly reduce the use of manpower, power, and space resources, making them crucial for the rapid establishment of emergency communication networks. Small antenna units facilitate compact array designs, saving space. Low-profile antenna structures facilitate antenna integration. High-performance antennas can provide wide beams and high gain. Therefore, the development of compact, high-performance aerial base station antennas holds great potential and promise for future applications.

[0003] Currently, miniaturizing antennas involves two main approaches: reducing lateral dimensions and lowering profile height. Common approaches include adding parasitic structures to shift the operating frequency toward lower frequencies, or creating slots and slits on the radiating surface to extend the surface current path, thereby miniaturizing the antenna. (See "Y. Liu, H. Yi, F.-W. Wang and S.-X. Gong, "A Novel Miniaturized Broadband Dual-Polarized Dipole Antenna for Base Station," in IEEE Antennas and Wireless Propagation Letters, vol. 12, pp. 1335-1338, 2013, doi:10.1109 / LAWP.2013.2285373"). The size of the antenna is only 0.513λ0×0.513λ0×0.388λ0. By loading a parasitic ring to broaden the low-frequency bandwidth of the antenna, and loading a director to broaden the high-frequency bandwidth of the antenna, the working bandwidth is 1.71GHz-2.69GHz with a standing wave ratio below 1.5, the isolation is greater than 22dB, and the gain reaches 8dBi.

[0004] There are three main approaches to broadband base station antenna design. The first is the symmetrical dipole antenna, which is widely used in base station antenna design due to its wide operating bandwidth, high gain, and simple processing. However, it has disadvantages: the dipole requires balanced feeding, and the feeding structure is complex. Common methods for widening the bandwidth include slotting the radiating structure, loading parasitic structures, and using a broadband balun structure for feeding. The second is the microstrip patch antenna, which is also widely used in base station antenna design due to its low profile, light weight, and ease of integration. However, its disadvantage is its very narrow bandwidth. Common methods for broadbanding include loading parasitic structures, using multi-layer microstrip structures, and adopting slot-coupled feeding. The third is the electromagnetic dipole antenna, which utilizes the complementary radiation patterns of the electric and magnetic dipoles to achieve a stable radiation pattern and gain within the operating frequency band. The document "Y. Liu, H. Yi, F.-W. Wang and S.-X. Gong, "A Novel Miniaturized Broadband Dual-Polarized Dipole Antenna for Base Station," in IEEE Antennas and Wireless Propagation Letters, vol. 12, pp. 1335-1338, 2013, doi: 10.1109 / LAWP.2013.2285373." uses two layers of stacked patches to increase the impedance bandwidth of the antenna. By coupling feeding and introducing a short-circuit via array characterized by the sidewalls, the impedance matching is enhanced. The antenna achieves a relative bandwidth of 19% with a differential reflection coefficient of less than -10 dB.

[0005] With the dense deployment of aerial base station antennas, coupling between antennas is becoming increasingly severe. This increased coupling degrades key antenna metrics such as standing waves, radiation patterns, and efficiency. Isolation is often used to quantify the strength of this coupling, defined as the ratio of the power transmitted by one antenna to the power received by another. Antenna coupling occurs in two ways: spatial coupling and surface wave coupling. Methods for improving isolation include: increasing the spatial distance between the two antennas to reduce surface wave and spatial coupling; employing orthogonal polarizations for the two antennas; placing obstacles in the electromagnetic coupling path to block electromagnetic coupling; and employing surface filtering designs on the common ground. The document "Z. Zhou, Z. Wei, Z. Tang and Y. Yin, "Design and Analysis of a Wideband Multiple-Microstrip Dipole Antenna with High Isolation," in IEEE Antennas and Wireless Propagation Letters, vol. 18, no. 4, pp. 722-726, April 2019, doi: 10.1109 / LAWP.2019.2901838." proposes a dual-polarized microstrip dipole antenna with an operating frequency between 1.68 GHz and 2.75 GHz. The dipole and balun feed are separated by a cross-slot coupler, resulting in an isolation greater than 37 dB. The antenna has dimensions of 0.87λ0 × 0.87λ0 × 0.18λ0.

[0006] The current trend in the design of miniaturized aerial base station antennas is towards wide bandwidth, miniaturization, high isolation, high gain, and low cost. However, current research still presents several challenges. First, while reducing the size of base station antennas, mutual coupling between antenna elements increases, which degrades key antenna performance indicators such as standing waves, radiation patterns, and efficiency. Therefore, miniaturizing aerial base station antennas while maintaining high isolation between antennas is crucial. Second, the so-called miniaturized base station antenna elements in existing research are mostly approximately 0.45λ0 × 0.45λ0 in planar dimensions and possess complex structures. Third, the feed networks currently used for miniaturized base station antennas primarily utilize coaxial cables and PCB stripline / microstrip lines. While coaxial feed networks offer a simple structure and high gain, they are difficult to integrate. PCB stripline / microstrip feed networks, while easy to integrate, suffer from high losses. Fourth, the paper "Y. Liu, H. Yi, F.-W. Wang and S.-X. Gong, "A Novel Miniaturized Broadband Dual-Polarized Dipole Antenna for Base Station," in IEEE Antennas and Wireless Propagation Letters, vol. 12, pp. 1335-1338, 2013, doi:10.1109 / LAWP.2013.2285373" achieves high gain and broadband while also requiring a high profile antenna height of 0.388λ0. This high profile and low wind resistance hinder carrier conformality. Therefore, innovating antenna structures and designing a new type of integrated aerial base station antenna with miniaturization, broadband, high isolation, high gain, wide beam, and low cost is a highly challenging task.

[0007] Through the above analysis, the problems and defects of the existing technology are as follows:

[0008] (1) While reducing the size of base station antennas, the mutual coupling between antenna units will increase. The increase in mutual coupling will deteriorate key antenna indicators such as standing waves, radiation patterns, and efficiency.

[0009] (2) The so-called miniaturized base station antenna units studied in the prior art mostly have a planar size of around 0.45λ0×0.45λ0 and a complex structure.

[0010] (3) The main implementation forms of the feeding network of miniaturized base station antennas are coaxial lines, PCB strip lines / microstrip lines, etc. Although the coaxial line feeding structure is simple and has high gain, it is not easy to integrate.

[0011] (4) In the prior art, while achieving high gain and broadband, the cross-sectional height of the antenna reaches 0.388λ0, which has a high profile and low wind resistance, but is not conducive to achieving carrier conformality.

[0012] The difficulty of solving the above problems and defects is: it is necessary to innovate a structure that can not only achieve miniaturization, but also improve the isolation between antennas, and ensure the high gain and wide bandwidth of the antenna, and can meet the characteristics of simple processing and high integration. However, the current research profile of antennas in this direction is generally high, so it is necessary to comprehensively consider the influence of various aspects and balance the requirements of various performance indicators of base station antennas.

[0013] The significance of addressing these issues and deficiencies lies in the fact that, as a core component of emergency communication base stations, miniaturized, high-performance, and low-cost aerial base station antennas are in high demand and of great practical significance in the current development of emergency communication systems. They are an excellent means of integrated air-ground emergency communication, offering greater capacity, higher system throughput, and improved service quality. By adjusting the platform's height, communication distances can be extended to several kilometers or even tens of kilometers, expanding coverage. Furthermore, the aerial platform's convenient and flexible networking capabilities make it particularly useful in challenging environments such as mountainous areas and scattered islands. Summary of the Invention

[0014] In response to the problems existing in the prior art, the present invention provides a high-isolation, low-profile, broadband base station antenna, a control method and an application thereof.

[0015] The present invention is implemented as follows: a control method for a high-isolation, low-profile, broadband base station antenna. The control method for the high-isolation, low-profile, broadband base station antenna feeds the patch through slot coupling feeding, embeds the substrate integrated metal through-hole into the dual-polarized antenna, isolates the original dual-polarized feeding part, forms two independent areas at the feeding point, and embeds metal through-holes around the substrate integrated waveguide; by optimizing and adjusting the height of the upper and lower patches, the resonant frequency of the antenna is adjusted, and ultimately the antenna achieves high isolation, low profile, and broadband.

[0016] Another object of the present invention is to provide a high-isolation, low-profile, broadband base station antenna and a control method thereof, wherein the high-isolation, low-profile, broadband base station antenna is provided with an upper and lower dielectric substrate;

[0017] The front surfaces of the upper and lower dielectric substrates are respectively covered with a circular patch, and a substrate integrated waveguide is arranged on the lower side of the lower dielectric substrate; the upper surface of the substrate integrated waveguide is grounded, and the lower surface of the substrate integrated waveguide is composed of two microstrip feeds.

[0018] Furthermore, the circular patch of the upper dielectric substrate is hollowed out in the middle and has four small rectangles symmetrically grooved along the x-axis and the y-axis around its periphery.

[0019] Furthermore, the annular patch of the lower dielectric substrate has a radius slightly smaller than that of the upper patch, and is symmetrically grooved with four narrow rectangles along the x-axis and the y-axis, with the tops of the narrow rectangles close to the edges of the patch.

[0020] Furthermore, the length and width of the substrate-based waveguide are the same as those of the dielectric substrate.

[0021] Furthermore, four dumbbell-shaped slots are opened on the upper surface of the substrate integrated waveguide, and each pair of dumbbell-shaped slots consists of one long and one short.

[0022] Furthermore, the pair of dumbbell-shaped slots are located directly above the microstrip feed, and the other pair of dumbbell-shaped slots are located directly above another microstrip feed.

[0023] Furthermore, the feeding structure in the microstrip feeding adopts a microstrip dual-port side feeding mode, wherein each section of the feeding structure is composed of a three-stage impedance transformer, a microstrip line and a parasitic branch.

[0024] Furthermore, metal through holes are embedded around the substrate integrated waveguide.

[0025] Another object of the present invention is to provide a control method for the high-isolation, low-profile broadband base station antenna. The control method adopts the results of coupling multi-layer patch antennas and adopts an aperture-coupled feeding method; first, a dual microstrip feeder is used for side feeding, and a dielectric integrated waveguide metal via is used to embed a metal via between the two feeds. The two feeder terminals are loaded with open-circuit branches, and the two feeders are perpendicular to each other; a slot is opened on the upper surface of the dielectric integrated waveguide to couple the electromagnetic wave energy to the upper patch. The slot is in the shape of two dumbbells, coplanar with the floor, and facing the feeder. The electromagnetic wave energy is coupled to the lower patch through the slot, and the lower patch couples the electromagnetic wave energy to the first patch through four long slots.

[0026] Another object of the present invention is to provide an application of the high-isolation, low-profile broadband base station antenna in an air-based communication platform.

[0027] Combining all the above technical solutions, the advantages and positive effects of the present invention are as follows: the present invention utilizes cutting-edge technologies such as aperture-coupled feeding and substrate dielectric integrated waveguide technology, integrates multi-section impedance matching technology, additional branches and other technologies, and broadens the bandwidth by constructing multiple resonances. The present invention solves the problems of low profile, broadband and high isolation of base station antennas. The bandwidth of the unit antenna is less than 2 in the range of 2.3-2.70GHz, and the isolation within the frequency band reaches below -32dB. The antenna has excellent performance, simple structure, easy processing and installation, and carrier conformal. The cross-sectional height of the antenna unit is only 0.103λ0, and the planar size is 0.425λ0×0.425λ0.

[0028] At the same time, the present invention realizes dual polarization, can simultaneously cover multiple frequency bands such as TD-LTE, CDMA200, TD-SCDMA and 2.4G WLAN, meet the needs of different existing wireless communication systems, and has good practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic structural diagram of a high-isolation, low-profile, broadband base station antenna provided by an embodiment of the present invention.

[0030] Figure 2 This is a front view of the antenna provided by an embodiment of the present invention.

[0031] Figure 3 It is a schematic diagram of the antenna feeding structure provided by an embodiment of the present invention.

[0032] Figure 4 Schematic diagram of the -10dB impedance bandwidth of the antenna provided by an embodiment of the present invention.

[0033] Figure 5 This is an isolation curve diagram of the antenna provided by an embodiment of the present invention.

[0034] In the figure: 1. Dielectric substrate; 2. Second feeding port; 3. Substrate integrated waveguide; 4. Third feeding port; 5. Floor; 6. Metal through hole; 7. Parasitic branch; 8. Slotted gap; 9. Three-stage impedance transformer; 10. Microstrip feeding. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0036] To address the challenges of the existing technology, the present invention provides a high-isolation, low-profile, broadband base station antenna, control method, and application. The invention is described in detail below with reference to the accompanying figures. Because this antenna's bandwidth covers 2.3-2.7 GHz, fully encompassing the 4G-LTE frequency band, it can be used as an aerial base station antenna for emergency communications. For example, a Wing Loong 2 drone carrying this base station antenna could fly over a disaster area, establishing a link with a 4G base station to provide communication support for the disaster area.

[0037] Ordinary technicians in the industry can also use other steps to implement the high isolation, low profile, broadband base station antenna provided by the present invention. Figure 1 The high-isolation, low-profile, broadband base station antenna provided by the present invention is only a specific embodiment.

[0038] like Figure 1-Figure 2As shown, the high-isolation, low-profile, broadband base station antenna provided by the embodiment of the present invention is composed of two dielectric substrates 1, a circular patch, a ground plane 5 and a substrate-integrated waveguide 3.

[0039] The front of the upper and lower dielectric substrates 1 are respectively covered with a circular patch, which is a radiating patch; the upper patch is a circular patch with a hollow circular periphery in the middle and four small rectangles grooved symmetrically along the x-axis and y-axis; the radius of the lower patch is slightly smaller than that of the upper patch, and four narrow rectangles are grooved symmetrically along the x-axis and y-axis, with the top of the narrow rectangle close to the edge of the patch.

[0040] A substrate integrated waveguide 3 is provided on the lower side of the lower dielectric substrate. The length and width of the substrate integrated waveguide 3 are the same as those of the dielectric substrate 1. The upper surface of the substrate integrated waveguide 3 is grounded to a ground plane 5. The lower surface of the substrate integrated waveguide 3 is composed of two microstrip feeds 10.

[0041] The top surface of the substrate-integrated waveguide 3 is provided with four dumbbell-shaped slots 8. Each pair of dumbbell slots consists of one long and one short slot. One pair of dumbbell slots is located directly above a microstrip feed 10, while the other pair of dumbbell slots is located directly above another microstrip feed 10. The feeding structure in the microstrip feed 10 adopts a microstrip dual-port side-feed method. Each feeding structure consists of a three-stage impedance transformer 9, a microstrip line, and a parasitic stub 7. Power is fed to the patch via slot-coupled feeding.

[0042] The patch is fed via slot coupling, and a substrate-integrated metal via (6) is embedded within the dual-polarized antenna, isolating the original dual-polarized feed portion. This creates two independent regions at the feed point, enhancing the isolation between the two feed ports. Metal vias (6) are embedded around the substrate-integrated waveguide (3), enhancing the antenna's capacitive characteristics and improving its matching. By optimizing the height of the upper and lower patches and adjusting the antenna's resonant frequency, the antenna achieves high isolation, a low profile, and broadband performance.

[0043] This antenna structure is the result of a coupled multi-layer patch antenna. It adopts an aperture-coupled feeding method to greatly reduce the mutual interference between the feed source and the patch. First, a dual microstrip feed line is used for side feeding. The idea of ​​dielectric integrated waveguide metal vias is used to embed metal vias between the two feeds to enhance the isolation effect of the two feed ports. The two feed line terminals are loaded with open-circuit branches to improve radiation efficiency. The two feed lines are perpendicular to each other, which is conducive to the formation of dual polarization. A slot is opened on the upper surface of the dielectric integrated waveguide to couple the electromagnetic wave energy to the upper patch. The slot is in the shape of two dumbbells, coplanar with the floor, and facing the feed line. The electromagnetic wave energy is coupled to the lower patch through the slot. The lower patch couples the electromagnetic wave energy to the first patch through four long slots. By optimizing the relative size of the patches and the relative distance between the patches, the coupling degree between the slot and the lower patch and the coupling degree between the two patches are adjusted, so that the dual resonant frequencies are close, thereby greatly broadening the working bandwidth of the antenna.

[0044] like Figure 4 and Figure 5 As shown, the bandwidth operating band is from 2.3-2.7 GHz, the antenna isolation is less than -32Db, and the cross-sectional height is only 0.103λ0 (the wavelength corresponding to 2.4 GHz).

[0045] In the description of the present invention, unless otherwise specified, "plurality" means two or more; terms such as "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," and "tail" indicate positions or relationships based on those shown in the accompanying drawings. These terms are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components 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, terms such as "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0046] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with this technical field within the technical scope disclosed by the present invention and within the spirit and principles of the present invention should be covered by the scope of protection of the present invention.

Claims

1. A control method for a high-isolation, low-profile, broadband base station antenna, characterized in that: The control method for a high-isolation, low-profile, broadband base station antenna feeds the patch through slot coupling feeding, embeds a substrate-integrated metal through-hole into the dual-polarized antenna, isolates the original dual-polarized feeding portion, forms two independent regions at the feeding location, and embeds metal through-holes around the substrate-integrated waveguide. By optimizing and adjusting the heights of the upper and lower patches and adjusting the resonant frequency of the antenna, the antenna ultimately achieves high isolation, low profile, and broadband performance. The high-isolation low-profile broadband base station antenna of the control method of the high-isolation low-profile broadband base station antenna is provided with an upper and lower dielectric substrate; The front surfaces of the upper and lower dielectric substrates are respectively covered with a circular patch, and a substrate integrated waveguide is provided on the lower side of the lower dielectric substrate; The upper surface of the substrate integrated waveguide is grounded, and the lower surface of the substrate integrated waveguide is composed of two microstrip feeds; The circular patch of the upper dielectric substrate is hollowed out in the middle and has four small rectangles symmetrically grooved along the x-axis and the y-axis around its periphery.

2. The high-isolation, low-profile, broadband base station antenna according to claim 1, wherein: The circular patch of the lower dielectric substrate has a radius slightly smaller than that of the upper patch, and is symmetrically grooved with four narrow rectangles along the x-axis and the y-axis, with the tops of the narrow rectangles close to the edges of the patch.

3. The high-isolation, low-profile, broadband base station antenna according to claim 1, wherein: The length and width of the substrate-based waveguide are the same as those of the dielectric substrate.

4. The high-isolation, low-profile, broadband base station antenna according to claim 1, wherein: Four dumbbell-shaped slots are opened on the upper surface of the substrate integrated waveguide, and each pair of dumbbell-shaped slots consists of a long slot and a short slot.

5. The high-isolation, low-profile, broadband base station antenna according to claim 4, wherein: The pair of dumbbell-shaped slots are located directly above the microstrip feed, and the other pair of dumbbell-shaped slots are located directly above another microstrip feed.

6. The high-isolation, low-profile, broadband base station antenna according to claim 1, wherein: The feeding structure in the microstrip feeding adopts a microstrip dual-port side feeding mode, wherein each section of the feeding structure is composed of a three-stage impedance transformer, a microstrip line and a parasitic branch; The substrate integrated waveguide is embedded with metal through holes around it.

7. A control method for a high-isolation, low-profile, broadband base station antenna according to any one of claims 1 to 6, characterized in that: The control method adopts the results of coupled multi-layer patch antennas and adopts an aperture-coupled feeding mode. First, a dual microstrip feeder is used for side feeding. A metal via is embedded between two feeders using a dielectric integrated waveguide. Open branches are loaded at the two feeder terminals, and the two feeders are perpendicular to each other. Slits are opened on the upper surface of the dielectric integrated waveguide to couple electromagnetic wave energy to the upper patch. The slots are two dumbbell-shaped, coplanar with the floor, and facing the feeder. The electromagnetic wave energy is coupled to the lower patch through the slots, and the lower patch couples the electromagnetic wave energy to the first patch through four long slots.

8. Use of the high-isolation, low-profile, broadband base station antenna according to any one of claims 1 to 6 in an air-based communication platform.

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