A high-gain wide-bandwidth omnidirectional antenna structure

Abstract

The application discloses a high-gain wide-band omnidirectional antenna structure, which comprises a dielectric plate, a radiation choke component, the radiation choke component comprising a radiation oscillator array and a choke sleeve, the radiation oscillator array comprising a plurality of oscillator units arranged along the axial direction of the dielectric plate, at least one choke sleeve arranged on one side of the oscillator units along the axial direction of the dielectric plate, the radiation oscillator array sharing all the choke sleeves, a grounding wire and U-shaped coupling oscillators, each U-shaped coupling oscillator covering a dipole group of each of the oscillator units to form an antenna oscillator. The application greatly simplifies the antenna structure through the collaborative design of the integrated choke sleeve and the U-shaped coupling oscillator, realizes high gain and excellent horizontal plane pattern consistency in a wide frequency band, and uses the electromagnetic reflection and boundary constraint characteristics of metal to realize clutter suppression and precisely constrain the radiation pattern, so as to improve the consistency of the horizontal plane pattern.

Description

Technical Field

[0001] This invention relates to the field of radio frequency antenna technology, and in particular to a high-gain, wide-bandwidth omnidirectional antenna structure suitable for signal transmission and reception in outdoor mobile communication, wireless private networks, Internet of Things and other scenarios. Background Technology

[0002] With the rapid development of technologies such as 5G communication, industrial IoT, and emergency communication, communication systems are placing higher demands on the overall performance of antennas: they need to have high gain to expand signal coverage, wide bandwidth to support multi-band compatibility, and also require horizontal performance. Figure 1 It exhibits good consistency, strong anti-interference capability, and is easy to mass-produce to meet the needs of large-scale deployment. Traditional omnidirectional antennas generally suffer from several technical defects: firstly, the vibrator and choke sleeve are mostly separate metal structures, making it difficult to control tolerances during assembly, resulting in unstable sidelobe suppression and inconsistent antenna direction. Figure 1 First, the signal uniformity of the multi-element array is poor, making it impossible to guarantee the uniformity of the signal in the communication coverage area. Second, there is a technical contradiction between gain and bandwidth, and conventional design schemes cannot meet the usage requirements of high gain and wide bandwidth, resulting in large signal transmission loss. Third, the anti-interference capability is weak. In complex electromagnetic environments, external clutter can easily interfere with the internal vibrators, and the antenna's own radiation can also affect the normal operation of surrounding equipment. Fourth, the fixing of multi-element arrays often uses metal connectors, which can easily introduce additional electromagnetic interference, destroy the radiation uniformity of the array, and the feed connectors need to be additionally fixed, resulting in redundancy in the overall structure and complicated assembly procedures.

[0003] Therefore, there is an urgent need to design an omnidirectional antenna structure that is low-cost, high-gain, wide-bandwidth, and takes into account weather resistance, electrical performance, and production consistency, in order to overcome the shortcomings of existing technologies. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies, such as high cost, large tolerances in the fit between the vibrator and the choke, and poor directional properties of existing omnidirectional antennas. Figure 1 The antenna suffers from drawbacks such as poor consistency, significant contradiction between gain and bandwidth, weak anti-interference capability, electromagnetic interference introduced by fixed array, and the need for additional fixing of the feed connector. To address these issues, a high-gain, wide-bandwidth omnidirectional antenna structure is proposed. This antenna can cover a wide frequency band, with an H-plane pattern non-circularity ≤0.18dB and a gain ≥10dBi.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A high-gain, wide-bandwidth omnidirectional antenna structure, comprising: Medium plate; A radial choke assembly is disposed on the dielectric substrate; the radial choke assembly includes a radial oscillator array and a choke sleeve; the radial oscillator array includes a plurality of oscillator units arranged along the axial direction of the dielectric substrate; at least one of the choke sleeves is disposed on one side of each oscillator unit along the axial direction of the dielectric substrate; the radial oscillator array shares all of the choke sleeves. A grounding wire is provided on the dielectric plate and is also used to connect the oscillator unit and the choke sleeve; U-shaped coupled elements, each U-shaped coupled element covering the dipole group of each said element unit to form an antenna element.

[0006] As a preferred embodiment of the high-gain, wide-bandwidth omnidirectional antenna structure provided by the present invention, the choke sleeve is a λ / 4 impedance transformation choke sleeve.

[0007] As a preferred embodiment of the high-gain, wide-bandwidth omnidirectional antenna structure provided by the present invention, the U-shaped coupling element is a U-shaped component with a flange, and the flange abuts against the element arms located on both sides of the dielectric substrate.

[0008] In a preferred embodiment of the high-gain, wide-bandwidth omnidirectional antenna structure provided by the present invention, all U-shaped coupled elements on the same horizontal plane are rigidly connected and fixed by composite material tie rods.

[0009] As a preferred embodiment of the high-gain, wide-bandwidth omnidirectional antenna structure provided by the present invention, it further includes a feeding structure; the feeding point of the feeding structure is located at the center of the radiating dipole array.

[0010] As a preferred embodiment of the high-gain, wide-bandwidth omnidirectional antenna structure provided by the present invention, the feeding structure is a feeding structure that realizes multiple parallel stages and one series stage.

[0011] As a preferred embodiment of the high-gain, wide-bandwidth omnidirectional antenna structure provided by the present invention, the composite material rod is also used to fix the connector component of the feed structure.

[0012] As a preferred embodiment of the high-gain, wide-bandwidth omnidirectional antenna structure provided by the present invention, the composite material rod is made of non-metallic insulating material and is fixed to the U-shaped coupling element by an insulating fastener.

[0013] As a preferred embodiment of the high-gain, wide-bandwidth omnidirectional antenna structure provided by the present invention, the feeding structure is directly connected to the radiation choke component, and impedance matching is achieved through the impedance transformation characteristics of the λ / 4 impedance transformation choke sleeve.

[0014] In a preferred embodiment of the high-gain, wide-bandwidth omnidirectional antenna structure provided by the present invention, the U-shaped coupled vibrator and the vibrator unit are isolated from each other and fixed by insulating fasteners.

[0015] As a preferred embodiment of the high-gain, wide-bandwidth omnidirectional antenna structure provided by the present invention, it also includes an antenna radome for covering all components such as the dielectric substrate, U-shaped coupled vibrator, composite material tie rod, and feeding structure.

[0016] In a preferred embodiment of the high-gain, wide-bandwidth omnidirectional antenna structure provided by the present invention, the dielectric substrate is an RF substrate.

[0017] As a preferred embodiment of the high-gain, wide-bandwidth omnidirectional antenna structure provided by the present invention, the omnidirectional antenna structure has an omnidirectional radiation gain (Gain) ≥ 10 dBi and an H-plane pattern non-circularity ≤ 0.18 dB within the operating frequency band.

[0018] Compared with the prior art, the present invention has the following beneficial effects: (1) Gain and bandwidth synergistic optimization: The integrated design of the radiating dipole array sharing the choke sleeve effectively reduces the energy loss of the sidelobe and concentrates the radiated energy on the main lobe, significantly improving the antenna gain; the constraint effect of the U-shaped coupled dipole, combined with the impedance matching optimization of the choke sleeve, solves the technical contradiction between gain and bandwidth, and achieves wide-band signal coverage such as 698MHz-960MHz full-band coverage and a bandwidth ratio of more than 32%, while also possessing excellent omnidirectional radiation and anti-interference performance.

[0019] (2) Direction Figure 1 Excellent uniformity: The U-shaped coupled oscillator utilizes the electromagnetic reflection and boundary constraint characteristics of metal to precisely constrain the radiation pattern, effectively improving the uniformity and consistency of the horizontal plane pattern and significantly reducing the lobe fluctuation of the H-plane pattern. Combined with the common-mode rejection function of the choke sleeve, the H-plane pattern non-circularity of the antenna is ≤0.18dB throughout the entire operating frequency band, with low sidelobe levels, ensuring uniform signal strength in the communication coverage area.

[0020] (3) Outstanding anti-interference capability: The U-shaped coupled oscillator can block external clutter interference, and the choke sleeve can effectively suppress common-mode interference and stray radiation; the insulation design of the composite material tie rod avoids the introduction of additional electromagnetic interference and improves the communication stability in complex electromagnetic environments.

[0021] (4) Simplified structure and easy mass production: The radiating element and the choke sleeve are integrated on the same dielectric board, eliminating most of the welding process of traditional separate structures and reducing connection nodes; the U-shaped coupling element adopts a standardized design, and the assembly tolerance is easy to control; the composite material tie rod has the dual functions of array fixing and feed connector fixing, eliminating additional fixing parts, simplifying the assembly process of multi-element array, reducing antenna weight and production cost, and is suitable for mass production.

[0022] (5) Strong weather resistance and stability: The antenna cover has excellent outdoor weather resistance and can withstand harsh environments for a long time; the integrated internal structure design and the rigid fixation of the composite material rod improve the overall structural stability of the antenna and extend its outdoor service life. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the following description of the embodiments will be briefly introduced. The accompanying drawings described below are only one of the preferred embodiments of the present invention.

[0024] Figure 1 This is a schematic diagram of the high-gain, wide-bandwidth omnidirectional antenna structure of the present invention; Figure 2 for Figure 1 A schematic diagram of the decomposition process; Figure 3 This is a schematic diagram of a part of the omnidirectional antenna structure of the present invention; Figure 4 This is a schematic diagram of a portion of a dielectric plate with a radiation choke assembly according to the present invention, including top views of the front and back sides of the dielectric plate; Figure 5 for Figure 4 A schematic diagram of the decomposition process; Figure 6 for Figure 4 Front view; Figure 7 This is another schematic diagram of the high-gain, wide-bandwidth omnidirectional antenna structure of the present invention; Figure 8 for Figure 7 A schematic diagram of a part of it; Figure 9 This is a schematic diagram of the front and back sides of the dielectric substrate and the feeding structure of the present invention having a radiation choke component; Figure 10 The image shows the horizontal radiation pattern of the high-gain, wide-bandwidth omnidirectional antenna structure tested in the 0.7-0.96 GHz range according to an embodiment of the present invention. Figure 11 The vertical plane radiation pattern of the high-gain, wide-bandwidth omnidirectional antenna structure of this invention was tested in the 0.7-0.96 GHz range. Figure 12 The horizontal radiation pattern of the omnidirectional antenna structure in Comparative Example 1 was tested in the 0.7-0.96 GHz range. Figure 13 The vertical plane radiation pattern of the omnidirectional antenna structure in Comparative Example 1 was tested in the 0.7-0.96 GHz range. Figure 14 The horizontal radiation pattern of the omnidirectional antenna structure in Comparative Example 2 was tested in the 0.7-0.96 GHz range. Figure 15The vertical plane radiation pattern of the omnidirectional antenna structure in Comparative Example 2 was tested in the 0.7-0.96 GHz range. Figure 16 The horizontal radiation pattern of the omnidirectional antenna structure in Comparative Example 3 was tested in the 0.7-0.96 GHz range. Figure 17 The vertical plane radiation pattern of the omnidirectional antenna structure in Comparative Example 3 was tested in the range of 0.7-0.96 GHz.

[0025] In the diagram, the components are: dielectric plate-1, front side-11, back side-12, oscillator unit-2, first oscillator arm-211, second oscillator arm-212, first coupling line-213, second coupling line-214, choke sleeve-3, first choke section-31, second choke section-32, metal wire-33, metal via-4, grounding wire-5, U-shaped coupling oscillator-6, U-shaped component-61, flange-62, corner-63, insulating fastener-7, composite material pull rod-8, power supply structure-9, power supply point-91, input power supply line-92, transmission line-93, first-level parallel line-93a, second-level parallel line-93b, series line-93a', electrical connection line-94, connector component-10, and collinear end-emitting oscillator array-A. Detailed Implementation

[0026] To make the technical solution of the present invention clearer and easier to understand, the present invention will now be described in further detail with reference to specific embodiments. Preferred embodiments of the present invention are given below with reference to the accompanying drawings to illustrate the technical solution of the present invention in detail. Here, the corresponding accompanying drawings will be provided for detailed description of the present invention. It should be particularly noted that the preferred embodiments described herein are only for illustration and explanation of the present invention and are not intended to limit or restrict 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.

[0027] The structure and numbering of the present invention will be described in detail below with reference to the embodiments shown in the accompanying drawings.

[0028] like Figure 1-9 As shown in the figure, this embodiment illustrates a high-gain, wide-bandwidth omnidirectional antenna structure, specifically including a dielectric substrate 1, a radiation choke assembly and a grounding wire 5 formed on the dielectric substrate 1, and a U-shaped coupling element 6.

[0029] Dielectric substrate 1 is selected from RF substrates suitable for RF signal transmission. The RF substrate options can be chosen according to specific needs. For mainstream mass production, TG150 and above FR4 high-frequency boards are preferred to meet the large-scale deployment of conventional outdoor mobile communications and maximize the mass production advantages of the patent. For harsh environment, domestically produced polytetrafluoroethylene (PTFE) or rigid polyimide (PI) copper-clad RF substrates are selected to balance weather resistance and cost, and enhance the outdoor stability of the patent. For high-end high-performance, Rogers 4350B RF substrates can be selected to adapt to specific scenarios such as aerospace and aviation, achieving the patent's high gain / high consistency technical goals, as a supplement to the high-end model. Dielectric substrate 1 has two oppositely arranged surfaces, which are defined as the front 11 and the back 12.

[0030] The radiative choke assembly includes a radiative oscillator array and a choke sleeve 3.

[0031] The radiating oscillator array includes several oscillator units 2 arranged along the axial direction of the dielectric plate 1. In this embodiment, specifically, there are 9 oscillator units 2 arranged at intervals along the axial direction of the dielectric plate 1. It is understood that it is not limited to 9 units, and can be less than 9 units, such as 3, 4, 5, etc., or more than 9 units.

[0032] Each oscillator unit 2 includes two dipole groups 21 spaced apart along the axial direction of the dielectric plate 1. Each dipole group 21 includes a first oscillator arm 211 and a second oscillator arm 212. The first oscillator arm 211 is located on the front side 11 of the dielectric plate 1, and the second oscillator arm 212 is located on the back side 12 of the dielectric plate 1. The corresponding first oscillator arms 211 and second oscillator arms 212 are electrically connected to each other through metal vias 4 along the thickness direction of the dielectric plate 1. In one oscillator unit 2, the two first oscillator arms 211 of one dipole group 21 located at the side edge of the dielectric plate 1 are connected by a first coupling line 213, and the two second oscillator arms 212 of the other dipole group 21 located at the side edge of the dielectric plate 1 are connected by a second coupling line 214. The first coupling line 213 and the second coupling line 214 are respectively located on the front side 11 and the back side 12 of the dielectric plate 1.

[0033] At least one choke sleeve 3 is disposed on one side of each oscillator unit 2 along the axial direction of the dielectric plate 1, such as Figure 4 As shown, a choke sleeve 3 can be located on the upper side or the lower side of a vibrator unit 2. In this embodiment, a choke sleeve 3 is provided on one side of each vibrator unit 2.

[0034] The radiating dipole array shares all the aforementioned choke sleeves 3, which also function as common-mode current suppression, impedance matching, and the grounding layer for the radiating elements. The closer the choke sleeve 3 is to the dipole element 2, the greater its energy; the farther away, the less energy it has. Energy not completely choked by the first choke sleeve 3 is choked by the second, third, and other equidistant choke sleeves. This structural design effectively reduces sidelobe energy loss, concentrates radiated energy on the main lobe, and significantly improves antenna gain. The characteristic impedance adapts to impedance matching requirements, with a physical length of λ / 4 corresponding to the center frequency of the antenna's operating band. That is, the choke sleeve 3 is a λ / 4 impedance transformation choke sleeve 3, which also functions as dipole current common-mode suppression and standard impedance matching, effectively reducing sidelobe energy loss and improving antenna radiation efficiency. Integrating the radiating dipole array and choke sleeves 3 onto the dielectric substrate 1 simplifies the overall antenna structure and reduces assembly complexity and error risk.

[0035] Each choke sleeve 3 includes a first choke section 31 located on the front side 11 of the dielectric substrate 1 and a second choke section 32 located on the back side 12 of the dielectric substrate 1. The first choke section 31 and the second choke section 32 are correspondingly arranged along the thickness direction of the dielectric substrate 1 and are interconnected through metal vias 4. In one choke sleeve 3, the two first choke sections 31 located on the side edge of the dielectric substrate 1 are connected by a metal wire 33, while the second choke sections 32 located on the side edge of the dielectric substrate 1 are not connected and are in an open circuit state.

[0036] Grounding wire 5 is installed on dielectric board 1, serving as a grounding function and also effectively connecting the oscillator unit 2 and choke sleeve 3. In this embodiment, grounding wire 5 electrically connects all oscillator units 2 and choke sleeve 3 together, and also has parallel power supply and power distribution lines on the front, which function as an equivalent to the feeder sheath.

[0037] The U-shaped coupled oscillator 6 is the core component of the radiating unit, made of highly conductive aluminum alloy or metallic aluminum, or other alloys or metals with excellent conductivity. For example... Figure 5 As shown, each U-shaped coupled vibrator 6 covers a dipole group 21 of the vibrator unit 2 to form an antenna vibrator. That is, in this embodiment, each vibrator unit 2 and four U-shaped coupled vibrators 6 form a collinear end-fire vibrator array A, as shown. Figure 3 As shown. In this embodiment, the U-shaped coupling oscillator 6 does not cover the choke sleeve 3.

[0038] Furthermore, such as Figure 5 , Figure 6As shown, the U-shaped coupled vibrator 6 is a U-shaped component 61 with a flange 62. The opening of the U-shaped component 61 faces the vibrator element 2 and covers the vibrator element 2. The flange 62 abuts against the vibrator arms (first vibrator arm 211 / second vibrator arm 212) located on both sides of the dielectric substrate 1. The corner 63 of the U-shaped component 61 can be a right angle or a small rounded corner (the radius R of the small rounded corner is controlled at about 1mm, but is not limited to this), as shown in the figure. If a large arc R angle is used at the corner, it is equivalent to an elliptical coupled vibrator. The elliptical space is not fully utilized, and the bandwidth and gain of the antenna are relatively poor.

[0039] The U-shaped coupled oscillator 6 and the oscillator unit 2 are isolated from each other and fixed by insulating fasteners 7, such as Figure 2 , 5 As shown. Specifically, after the dielectric substrate 1 forms the radiation choke component, its surface is coated with a protective green oil, approximately 0.05mm thick. The green oil serves as an anti-oxidation protective layer for the copper-clad layer on the surface of the dielectric substrate 1, and also acts as an isolation layer between the PCB copper-clad layer and the U-shaped coupling vibrator 6. It utilizes the electromagnetic reflection and boundary constraint characteristics of metal to suppress clutter and precisely constrain the radiation pattern to improve the consistency of the horizontal plane radiation pattern. If a thin PCB board is bent into a semi-circle as the coupling vibrator and fixed to both sides of the PCB substrate by soldering, this solution has too many solder joints, is cumbersome to operate, and is prone to poor soldering leading to abnormal antenna intermodulation performance. Intermodulation performance is very difficult to control, and the soldering and labor costs are too high. In addition, the structural strength is also relatively weak. The U-shaped coupling vibrator can also achieve better non-circularity performance by adjusting the area of ​​the rectangular surface. Moreover, structurally, the rectangular structure is simple and convenient to process and assemble.

[0040] By leveraging the electromagnetic reflection and boundary constraint effects of metals, the radiation pattern can be precisely controlled, significantly improving the uniformity and consistency of the horizontal plane radiation pattern; effectively filtering out clutter interference, enhancing the antenna's anti-interference capability in complex electromagnetic environments, and reducing signal loss in the feed network; and simultaneously reducing the electromagnetic coupling effect of the antenna's own radiation on surrounding equipment.

[0041] Integrated design of radiating dipole and choke sleeve 3: The radiating dipole array and λ / 4 impedance transformation choke sleeve 3 are integrated on the same dielectric substrate 1. Combined with the electromagnetic confinement effect of U-shaped coupled dipole 6, the structure is greatly simplified and insertion loss is reduced. The confinement effect of U-shaped coupled dipole 6 on the radiation pattern significantly reduces the lobe undulation of the H-plane pattern. Combined with the common-mode rejection function of choke sleeve 3, the antenna has low non-circularity of the H-plane pattern and low sidelobe level throughout the entire operating frequency band, ensuring uniform signal strength in the communication coverage area.

[0042] Multi-element shared choke sleeve 3 design: As a shared structure of the radiating element array, the choke sleeve 3 effectively suppresses reverse current, significantly expands the antenna bandwidth, and improves radiation efficiency, breaking through the bottleneck of mutual constraint between gain and bandwidth of traditional omnidirectional antennas.

[0043] All U-shaped coupled oscillators 6 on the same horizontal plane are rigidly connected and fixed by composite material tie rods 8. The composite material tie rods 8 are made of non-metallic insulating material and are fixed to the U-shaped coupled oscillators 6 by insulating fasteners 7.

[0044] A non-metallic insulating material (such as nylon, polytetrafluoroethylene, or glass fiber reinforced PP, etc., for low-loss RF applications) is selected as the composite material pull rod 8. An insulating fastener 7 with an appropriate aperture is selected as the connector, which must simultaneously meet the fixing requirements of the composite material pull rod 8 and the U-shaped coupled vibrator 6. The composite material pull rod 8 serves both structural support and electrical isolation functions, and can also fix the connector component 10 of the feed structure 9, avoiding the introduction of electromagnetic interference while improving structural integration. This further simplifies the assembly process and improves mass production feasibility; at the same time, it avoids the additional electromagnetic interference introduced by metal connectors, improving the antenna's operational reliability in complex electromagnetic environments.

[0045] The feed point 91 of the feed structure 9 is located at the center of the radiating oscillator array. In this invention, the composite material tie rod 8 is also used to fix the connector component 10 of the feed structure 9. The feed structure 9 is directly connected to the radiating choke assembly, and impedance matching is achieved through the impedance transformation characteristics of the λ / 4 impedance transformation choke sleeve 3.

[0046] The feeding structure 9 adopts a standard 50Ω impedance coaxial feeding method. The feeding point 91 is located at the geometric center of the oscillator array. The inner conductor of the coaxial feeding wire is directly soldered to the pad of the feeding point 91 of the radiating choke assembly, ensuring a low-resistance and smooth current return path. Through the impedance transformation characteristics of the λ / 4 impedance transformation choke sleeve 3, precise impedance matching between the feeding structure 9 and the dielectric substrate 1 of the integrated radiating oscillator and choke sleeve 3 is achieved, reducing signal transmission loss. At the same time, the symmetry of the array feeding is ensured, avoiding radiation pattern distortion caused by feeding imbalance, and further improving the stability of radiation performance.

[0047] The feeding structure 9 also includes an input feed line 92 and several transmission lines 93. The input feed line 92 is the antenna's total RF signal input / output port, directly connected to the inner conductor of the external RF cable, with the other end connected to the feed point 91. The transmission lines 93 are used to connect adjacent vibrator elements 2, continuing to transmit the RF signal backward. At the same time, phase compensation is achieved through precise physical length (approximately equal to 1 / 2 wavelength of the center frequency of the operating band), ensuring that the next collinear end-fired vibrator array A radiates in phase with the previous collinear end-fired vibrator array A. Specifically, in this embodiment, the transmission line 93 includes a first-level parallel line 93a, a second-level parallel line 93b, and a series line 93a'. The first-level parallel line 93a, combined with a via and an electrical connection line 94, is used to connect adjacent collinear end-emitting dipole arrays A in parallel to form a parallel dipole array. The second-level parallel line 93b, combined with a via and an electrical connection line 94, is used to connect two pairs of parallel dipole arrays in parallel again, and then connect them in parallel to the feed point 91 to connect the input feed line 92. Using multi-level parallel connection can achieve a wider bandwidth and better performance. The series line 93a' is used to connect two collinear end-emitting dipole arrays A in series, and then connect other collinear end-emitting dipole arrays A in parallel to form a parallel dipole array.

[0048] If only a multi-stage parallel oscillator structure is used, the actual gain of the antenna will decrease as the frequency decreases, resulting in low gain in the low-frequency band. The operating frequency range of this embodiment is 698-960MHz. In conventional designs, the gain gradually decreases as the frequency decreases; the gain difference between the 800MHz and 900MHz bands is usually not significant, but in the 700MHz band, the gain decreases more rapidly, and the lower the frequency, the more significant the gain attenuation.

[0049] To address the aforementioned issues, this embodiment proposes a multi-stage parallel plus a single-stage series feeding structure, aiming to achieve equalized gain across the entire frequency band. Specifically, this embodiment sets the spacing between the series-connected collinear end-fire dipole arrays A to be equal to one dielectric wavelength in the low-frequency band, thereby achieving higher gain in the low-frequency band. By combining the parallel and series components, the high gain characteristics of the series component in the low-frequency band are utilized to compensate for the insufficient low-frequency gain of the parallel component, thereby improving the overall antenna gain level in the low-frequency band and ultimately achieving a more balanced gain distribution across the entire operating frequency band.

[0050] In this embodiment, the dielectric wavelength (λε) corresponding to the center frequencies of the three frequency bands of 700MHz, 800MHz, and 900MHz is approximately 210-220mm, 180-190mm, and 165-175mm, respectively. If only the gain of the 700MHz band is considered, the spacing of the series-fed elements can be set in the range of approximately 200-230mm. However, due to the narrow bandwidth limitation of the series-fed structure itself, in order to minimize the impact on the gain of the entire 698-960MHz operating frequency band, in actual design, a frequency located in the middle of the 700MHz and 800MHz bands (approximately 775-845MHz) can be selected, with a corresponding dielectric wavelength of approximately 180-215mm, as a compromise design reference range. Preferably, but not limited to, the spacing between the series-connected collinear end-fired element array A is set to 180-215mm.

[0051] In this embodiment, there are 9 collinear end-shooting oscillator arrays A. The first 8 collinear end-shooting oscillator arrays A are connected in pairs through 4 primary parallel lines 93a to form 4 parallel oscillator arrays. The last collinear end-shooting oscillator array A is connected in series with the previous collinear end-shooting oscillator array A through a series line 93a'. The two adjacent parallel oscillator arrays in the 4 parallel oscillator arrays are then connected in parallel through a secondary parallel line 93b.

[0052] The omnidirectional antenna structure also includes an antenna radome, which encloses all components such as the dielectric substrate 1, U-shaped coupled element 6, composite material tie rod 8, and feeding structure 9. The antenna radome is made of a low dielectric constant material (such as fiberglass) and coated with a composite coating (such as a nano-titanium dioxide composite coating) to enclose all internal components. This design avoids radome damage and provides wind, water, and corrosion resistance for outdoor use, allowing it to withstand long-term exposure to wind, rain, and ultraviolet radiation, ensuring stable antenna operation in harsh environments.

[0053] In this embodiment, the omnidirectional antenna structure has an omnidirectional radiation gain ≥ 10 dBi and an H-plane pattern non-circularity ≤ 0.18 dB within the operating frequency band. Figures 10-11 As shown.

[0054] By employing the above measures, the high-gain, wide-bandwidth omnidirectional antenna structure of the present invention achieves high gain, wide bandwidth, ideal omnidirectionality, and high efficiency. This scheme also features simple feeding, low intermodulation, and convenient assembly, making it an ideal omnidirectional antenna solution suitable for cellular base stations. Furthermore, this method is simple to implement, low-cost, and suitable for mass production, making it a preferred alternative to conventional broadband omnidirectional base station antennas. Moreover, it is also applicable and effective for the design and improvement of low-gain or narrow-bandwidth terminal omnidirectional antennas.

[0055] The fabrication and assembly process of the omnidirectional antenna of this invention: PCB assembly fabrication: The radiating oscillator array and λ / 4 impedance transformation choke sleeve 3 are fabricated on the PCB substrate 1 using printing technology. The soldering process of the feed point 91 pad is completed to ensure the connection and conduction between the oscillator and the choke sleeve 3. Component assembly: Cover the U-shaped coupled oscillator 6 on the dielectric plate 1 at the relative positions of the oscillator arms of the oscillator unit 2, ensuring that the spacing between the two is uniform, and fix the relative positions of the two by the insulating fastener 7; Array and connector fixing: The U-shaped coupling vibrators 6 on the same surface are arranged at the designed spacing. The composite material tie rod 8 is used and the composite material tie rod 8 is fixed to the U-shaped coupling vibrator 6 by the insulating fastener 7. At the same time, the connector component of the power supply structure 9 is rigidly connected to the composite material tie rod 8 to ensure that the array structure is stable and the power supply connector is not loose. Power supply welding: Weld the inner conductor of the coaxial power supply wire to the power supply pad of dielectric board 1, check the solder joint for any cold solder joints or short circuits, and ensure that the current return path is unobstructed; Outer enclosure encapsulation: The antenna top is fixed on the top of the antenna outer enclosure and sealed with adhesive. Then, the assembled internal components of the antenna are installed into the antenna outer enclosure. The bottom is sealed with a flange ring and then sealed with adhesive (outdoor weather-resistant silicone sealant) to complete the overall assembly of the antenna.

[0056] Comparative Example 1 The only difference between Comparative Example 1 and this embodiment is that there is no U-shaped coupling oscillator.

[0057] Comparative Example 2 The only difference between Comparative Example 2 and this embodiment is that it has only one choke sleeve.

[0058] Comparative Example 3 The only difference between Comparative Example 3 and this embodiment is that a hybrid power supply structure of multi-stage series connection plus one-stage parallel connection is adopted, that is, the first 8 collinear end-shooting oscillator arrays A are connected in series in sequence, and then connected in parallel with the last collinear end-shooting oscillator array A.

[0059] The tests in this embodiment and Comparative Examples 1-3 were conducted at 0.7-0.96 GHz, and the test data results are shown in Table 1 below. The test radiation patterns are as follows. Figures 10-17 As shown.

[0060] Table 1 Comparative data from tests conducted in the 0.7-0.96 GHz range.

[0061] Combining Table 1 and Figures 10-17 Compared with Comparative Examples 1-3, this embodiment has the best performance in terms of gain value, gain stability, beam pointing consistency, pattern consistency, non-circularity, and sidelobe level.

[0062] From Table 1 and Figure 10, Figure 11 and Figure 12 , Figure 13 It can be seen that without the aluminum alloy coupling element, the horizontal non-circularity index deteriorates. Based on the rectangular structure of the PCB substrate, the antenna's horizontal 360° direction can be regarded as four sectors at 90° angles. The effective electrical size of the radiator in each sector determines the radiation intensity in that direction. In this embodiment, by adjusting the "projection" size of the metal coupling element in these four directions, energy can be redistributed to compensate for the inherent deviation caused by the asymmetry of the PCB substrate shape and improve the non-circularity. Furthermore, without the aluminum alloy coupling element, the bandwidth narrows. In this embodiment, the metal coupling element can be equivalent to thickening the radiating arm of the element on the PCB substrate. Thickening the radiating arm can change the antenna's equivalent impedance and current distribution, allowing it to maintain good impedance matching over a wider frequency range. At the same time, the coupling of the metal coupling element can be fixed by introducing additional coupled resonant structures to form multiple resonant points, thereby widening the overall operating frequency band.

[0063] From Table 1 and Figure 10 , Figure 11 and Figure 14 , Figure 15 It can be seen that if multiple oscillator elements have only one choke, the main problem is that the gain will be lower than that of a multi-choke structure, and the vertical beam pointing will be inconsistent when the frequency band is wide. Because the choke's suppression function can reduce the sidelobes of the element pattern and narrow the vertical beam width of the element, the energy is more concentrated in the main radiation direction, thereby improving the gain. In this embodiment, the multi-choke scheme has a good choking effect, a smaller current at the bottom of the antenna main feed line, and a better intermodulation level than the single-choke method.

[0064] From Table 1 and Figure 10 , Figure 11 and Figure 16 , Figure 17 It can be seen that using a hybrid feeding structure with multiple series stages and one parallel stage results in a narrower radiation pattern bandwidth, with the actual usable bandwidth being only about 80MHz. Outside this bandwidth range, significant vertical beam distortion occurs, leading to a sharp drop in antenna gain. This embodiment employs a multi-stage parallel-one-stage series scheme to achieve equalized gain across the entire frequency band. By combining the parallel and series sections, the high gain characteristics of the series elements in the low-frequency band are utilized to compensate for the insufficient low-frequency gain of the parallel section, thereby improving the overall antenna gain level in the low-frequency band and ultimately achieving a more balanced gain distribution across the entire operating frequency band.

[0065] The embodiments described above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. The present invention can be implemented in many different forms; the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments or make equivalent substitutions for some of the technical features. Without departing from the concept and principle of the present invention, any equivalent structures made using the content of the present invention's specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the patent protection scope of the present invention.

Claims

1. A high-gain, wide-bandwidth omnidirectional antenna structure, characterized in that, It includes: Medium plate; A radiation choke assembly is disposed on the dielectric substrate; The radial choke assembly includes a radial oscillator array and a choke sleeve; the radial oscillator array includes a plurality of oscillator units arranged along the axial direction of the dielectric plate; at least one of the choke sleeves is disposed on one side of each oscillator unit along the axial direction of the dielectric plate; the radial oscillator array shares all of the choke sleeves. A grounding wire is provided on the dielectric plate and is also used to connect the oscillator unit and the choke sleeve; U-shaped coupled vibrators, each U-shaped coupled vibrator covering the dipole group of each vibrator unit to form an antenna vibrator; A feeding structure, wherein the feeding point of the feeding structure is located at the center of the radiating oscillator array; The power supply structure is a power supply structure that realizes multiple parallel stages and one series stage; The radiating oscillator array includes several collinear end-emitting oscillator arrays A. The feeding structure includes a first-stage parallel line, a second-stage parallel line, and a series line. Except for the two collinear end-emitting oscillator arrays A connected in series by the series line, the remaining collinear end-emitting oscillator arrays A are paired up, and each pair is connected in parallel by the first-stage parallel line to form a parallel oscillator array. Each of the parallel oscillator arrays is connected in parallel to the feeding point by the second-stage parallel line. The spacing between the two collinear end-emitting oscillator arrays A connected in series by the series line is 180-215mm. Each oscillator unit and four U-shaped coupled oscillators form a collinear end-fire oscillator array A; The U-shaped coupling oscillator is a U-shaped component with a flange. The opening of the U-shaped component faces the oscillator unit and covers the oscillator unit. The flange abuts against the oscillator arms located on both sides of the dielectric plate.

2. The high-gain, wide-bandwidth omnidirectional antenna structure according to claim 1, characterized in that, The distance between the feed points of two adjacent oscillator units is greater than λ / 4, where λ is the wavelength of the center operating frequency.

3. The high-gain, wide-bandwidth omnidirectional antenna structure according to claim 1, characterized in that, The choke sleeve is a λ / 4 impedance transformation choke sleeve.

4. The high-gain, wide-bandwidth omnidirectional antenna structure according to claim 1, characterized in that, All U-shaped coupled oscillators on the same horizontal plane are rigidly connected and fixed by composite material tie rods.

5. The high-gain, wide-bandwidth omnidirectional antenna structure according to claim 4, characterized in that, The composite material tie rod is also used to fix the connector component of the power supply structure.

6. The high-gain, wide-bandwidth omnidirectional antenna structure according to claim 5, characterized in that, The power supply structure is directly connected to the radiation choke component, and impedance matching is achieved through the impedance transformation characteristics of the choke sleeve.

7. The high-gain, wide-bandwidth omnidirectional antenna structure according to claim 4, characterized in that, The composite material tie rod is made of non-metallic insulating material and is fixed to the U-shaped coupling oscillator by insulating fasteners.

8. The high-gain, wide-bandwidth omnidirectional antenna structure according to claim 1, characterized in that, The U-shaped coupled oscillator and the oscillator unit are isolated from each other and fixed by insulating fasteners.

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