Ultra-wideband omni-directional dipole antenna based on double-point feed and capacitive loading

Abstract

This invention discloses an ultra-wideband omnidirectional dipole antenna based on dual-point feeding and capacitive loading, comprising a dipole antenna and a Wilkinson power divider, wherein the dipole antenna and the Wilkinson power divider are connected by two symmetrically placed coaxial cables. To meet the application requirements of Wi-Fi antennas for multi-band coverage, wide coverage range, and high gain, this invention proposes an ultra-wideband omnidirectional dipole antenna based on dual-point feeding and capacitive loading. This antenna employs a wide-arm dipole structure and loads capacitor structures on the antenna arms to achieve mode compression; utilizing the inherent broadband characteristics of the dipole antenna, combined with mode adjustment, an ultra-wide operating bandwidth exceeding 140% can be achieved, thereby meeting most of the frequency band coverage requirements of Wi-Fi antennas.

Description

Technical Field

[0001] This invention belongs to the field of antenna technology, specifically relating to an ultrawideband omnidirectional dipole antenna based on dual-point feeding and capacitive loading. Background Technology

[0002] With the rapid development of the mobile internet and IoT industries, a large number of terminal devices need to access wireless networks, placing higher demands on the coverage, transmission rate, and signal capacity of wireless signals. This drives the development of Wi-Fi antenna technology towards multi-band, high-gain, and integrated technologies. In typical application scenarios such as homes and offices, to adapt to the randomness of terminal positions and orientations, Wi-Fi antennas must achieve uniform coverage without dead zones. Therefore, omnidirectional antennas, such as monopole or dipole antennas, are mostly chosen. Monopole antennas have a simple structure and relatively small size, but their radiation pattern is unstable, dependent on a large floor, and their radiation performance is easily affected by the installation environment. Dipole antennas have more uniform and stable omnidirectional radiation and higher radiation efficiency, making them more suitable for Wi-Fi antenna design. However, their operating bandwidth is relatively narrow, making it difficult to achieve multi-band coverage that fully meets application requirements.

[0003] To achieve stable ultra-wideband omnidirectional radiation characteristics, existing technologies employ various methods to extend the operating bandwidth of dipole antennas, such as parasitic element loading, mode compression, and wide-arm dipoles. Parasitic element loading methods increase resonant frequencies by introducing structures such as parasitic loop antennas, folded dipoles, or resonant arrays, thus realizing multi-frequency dipole antennas. Mode compression methods selectively lower the resonant frequencies of certain higher-order modes or raise the resonant frequency of the fundamental mode by adding stubs or capacitive / inductive structures to the dipole antenna, achieving bandwidth superposition. The broadband effect obtained by these two methods largely depends on the broadband characteristics of the dipole antenna itself. Traditional thin-wire dipoles, even with parasitic element loading or mode compression, still struggle to achieve a relative operating bandwidth exceeding 100%. Therefore, wide-arm dipole antennas are increasingly used in the design of broadband dipoles. By increasing the antenna arm width, the antenna's quality factor (Q value) can be significantly reduced, making its impedance characteristics change more smoothly with frequency, thus facilitating the achievement of ultra-wideband performance. However, with increased arm width, the surface current distribution of the dipole antenna tends to become uneven, leading to poorer non-circularity and deteriorating gain stability within the operating frequency band. Currently, most solutions struggle to achieve both ultra-wideband performance and low non-circularity.

[0004] Therefore, designing an ultrawideband omnidirectional dipole antenna that combines high gain and low non-circularity is of great significance for achieving "strong signal, uniform coverage, good compatibility, and stable connection" in Wi-Fi antenna applications. Summary of the Invention

[0005] To meet the application requirements of Wi-Fi antennas for multi-band coverage, wide coverage range, and high gain, this invention proposes an ultra-wideband omnidirectional dipole antenna based on dual-point feeding and capacitive loading. This antenna employs a wide-arm dipole structure and loads capacitors on the antenna arms to achieve mode compression. Utilizing the inherent broadband characteristics of the dipole antenna, combined with mode tuning, an ultra-wide operating bandwidth exceeding 140% can be achieved, thus meeting most of the frequency band coverage requirements of Wi-Fi antennas.

[0006] To address the low gain issue caused by the anti-superposition of third-order and fifth-order modes at the center of a wide-arm dipole, this invention employs a dual-point feeding scheme. Specifically, two feed points of equal amplitude and in phase are set on both sides of the dipole to suppress the superposition of third-order and fifth-order modes, thereby achieving high gain within the operating frequency band. To achieve dual-point feeding, the antenna requires a Wilkinson power divider; based on bandwidth requirements, this power divider adopts a sixth-order structure. The overall radiating structure of the antenna is printed on a single-layer dielectric substrate, with a low overall profile, making it easy to embed into router housings or terminal devices. It features a simple structure, ease of fabrication, and ease of integration, making it more suitable for large-scale commercial applications of Wi-Fi antennas.

[0007] To achieve the above objectives, the present invention provides an ultra-wideband omnidirectional dipole antenna based on dual-point feeding and capacitive loading, comprising a dipole antenna (1) and a Wilkinson power divider (2), wherein the dipole antenna (1) and the Wilkinson power divider (2) are connected by two symmetrically placed coaxial cables (1-17), wherein: The dipole antenna (1) includes a first dielectric substrate (1-7) and a metal radiating patch structure mounted on the first dielectric substrate (1-7); The Wilkinson power divider (2) includes a second dielectric substrate (2-10) and a power divider, microstrip line, isolation resistor (2-9) and metal ground plane (2-11) mounted on the second dielectric substrate (2-10). The dipole antenna (1) adopts a wide-arm structure and combines a loaded capacitor structure to achieve mode compression and bandwidth expansion; the Wilkinson power divider (2) is based on impedance transformation characteristics, and divides the input signal into two equal paths through two branches with the same impedance, outputting two signals with equal amplitude and the same phase, and the two output terminals are respectively connected to the two symmetrical feed points of the dipole antenna (1) through corresponding coaxial cables (1-17) to achieve dual-point symmetrical feeding.

[0008] As a further preferred embodiment of the above technical solution, the metal radiating patch structure includes a first metal radiating patch (1-1), a second metal radiating patch (1-2), a third metal radiating patch (1-3), a fourth metal radiating patch (1-4), a fifth metal radiating patch (1-5), a sixth metal radiating patch (1-6), chamfer A (1-8), chamfer B (1-9), chamfer C (1-10), chamfer D (1-11), gap A (1-12), gap B (1-13), and gap C (1-14), wherein: The first metal radiation patch (1-1) and the second metal radiation patch (1-2), the third metal radiation patch (1-3) and the fourth metal radiation patch (1-4), and the fifth metal radiation patch (1-5) and the sixth metal radiation patch (1-6) are all mirror-symmetrical. The first metal radiation patch (1-1) and the third metal radiation patch (1-3) are loaded with chamfer A (1-8) and chamfer B (1-9), and the second metal radiation patch (1-2) and the fourth metal radiation patch (1-4) are loaded with chamfer C (1-10) and chamfer D (1-11). A gap A (1-12) is loaded between the first metal radiation patch (1-1) and the second metal radiation patch (1-2); a gap B (1-13) is loaded between the first metal radiation patch (1-1) and the third metal radiation patch (1-3), and between the second metal radiation patch (1-2) and the fourth metal radiation patch (1-4). Gap C (1-14) is loaded between the third metal radiating patch (1-3) and the fifth metal radiating patch (1-5), and between the fourth metal radiating patch (1-4) and the sixth metal radiating patch (1-6). Gap A (1-12), gap B (1-13) and gap C (1-14) form a capacitive loading structure. As a transverse gap, the capacitive loading structure introduces capacitive characteristics, causing the overall resonant point of the dipole antenna (1) to shift towards the high frequency direction. Furthermore, through the wide arm structure formed by the first to sixth metal radiating patches, the current path is extended and the low frequency bandwidth is expanded.

[0009] As a further preferred embodiment of the above technical solution, the first dielectric substrate (1-7) is provided with a first metal through-hole (1-15) and a second metal through-hole (1-16), wherein: The first metal through hole (1-15) is connected to the inner conductors of the second metal radiating patch (1-2), the fourth metal radiating patch 1-4 and the two coaxial cables (1-17), respectively, and its length is the same as the thickness of the first dielectric substrate (1-7). The second metal through hole (1-16) is connected to the outer conductors of the first metal radiating patch (1-1), the third metal radiating patch (1-3), and the two coaxial cables (1-17), respectively, and its length is the same as the thickness of the first dielectric substrate (1-7).

[0010] As a further preferred technical solution to the above technical solution, the Wilkinson power divider (2) includes a first Wilkinson power divider (2-1), a second Wilkinson power divider (2-2), a third Wilkinson power divider (2-3), a fourth Wilkinson power divider (2-4), a fifth Wilkinson power divider (2-5), and a sixth Wilkinson power divider (2-6); the microstrip line includes microstrip line A (2-7) and microstrip line B (2-8), wherein: The input terminal of the first Wilkinson power divider (2-1) is the signal input port, and the two output terminals are connected to the second Wilkinson power divider (2-2). The Wilkinson power dividers of each stage are connected in sequence. Each Wilkinson power divider has two branch lines and an isolation resistor (2-9) between the two branch lines. The two output terminals of the sixth Wilkinson power divider (2-6) output signals of equal amplitude and in phase, which are respectively connected to microstrip line A (2-7) and microstrip line B (2-8). The Wilkinson power divider (2) is connected to two coaxial cables (1-17) via microstrip line A (2-7) and microstrip line B (2-8) to provide dual-point feeding for the dipole antenna (1); The metal floor (2-11) is disposed on the reverse side of the second dielectric substrate (2-10).

[0011] As a further preferred technical solution of the above technical solution, the Wilkinson power divider (2) adopts the form of a sixth-order Wilkinson power divider, and the branch line length of each order of Wilkinson power divider is close to 0.25λ0, where λ0 is the wavelength corresponding to the center operating frequency of the antenna element. All Wilkinson power dividers are composed of a ring structure made of bent microstrip lines, and the bends of the bent microstrip lines are chamfered. Isolation resistors of 100Ω, 120Ω, 220Ω, 330Ω, 470Ω, and 680Ω are set between the two branches of each Wilkinson power divider (2-9).

[0012] The beneficial effects of this invention are as follows: (1) The antenna uses a single-layer PCB substrate with a low profile, which is suitable for integration; it has a simple structure, is easy to process and has a low cost.

[0013] (2) The antenna operates in the frequency band of 0.8-5GHz, and the voltage standing wave ratio is less than 2, achieving full coverage of the communication frequency band.

[0014] (3) The antenna is fed by two points, and its gain is stable and relatively high within the operating frequency band; the omnidirectional radiation pattern is stable and the non-circularity is low. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the present invention; Figure 2 This is a three-dimensional structural schematic diagram of the dipole antenna of the present invention; Figure 3 This is a side view of the dipole antenna of the present invention in the x-direction; Figure 4 This is a top view of the dipole antenna of the present invention. Figure 5 This is a three-dimensional structural schematic diagram of the Wilkinson power divider of the present invention; Figure 6 This is a top front view of the Wilkinson power divider of the present invention; Figure 7 These are the simulation diagrams of |S11| and gain within the operating frequency band of this invention; Figure 8 The simulation results of the E-plane and H-plane radiation patterns of this invention at (a) 0.9 GHz, (b) 2.1 GHz, (c) 3.2 GHz, (d) 4.2 GHz, and (e) 5 GHz are as follows.

[0016] The reference numerals in the attached figures include: dipole antenna 1, first metal radiating patch 1-1, second metal radiating patch 1-2, third metal radiating patch 1-3, fourth metal radiating patch 1-4, fifth metal radiating patch 1-5, sixth metal radiating patch 1-6, first dielectric substrate 1-7, chamfer A1-8, chamfer B1-9, chamfer C1-10, chamfer D1-11, gap A1-12, gap B1-13, gap C1-14, and first metal through-hole. 1-15, Second metal through-hole; 1-16, Coaxial cable; 1-17, Wilkinson power divider 2, First Wilkinson power divider 2-1, Second Wilkinson power divider 2-2, Third Wilkinson power divider 2-3, Fourth Wilkinson power divider 2-4, Fifth Wilkinson power divider 2-5, Sixth Wilkinson power divider 2-6, Microstrip line A; 2-7, Microstrip line B; 2-8, Isolation resistor; 2-9, Second dielectric substrate; 2-10, Metal ground plane; 2-11. Detailed Implementation

[0017] The following description is intended to disclose the present invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0018] In the preferred embodiments of the present invention, those skilled in the art should note that the resistors and the like involved in the present invention can be considered as prior art.

[0019] Preferred embodiment.

[0020] This invention discloses an ultra-wideband omnidirectional dipole antenna based on dual-point feeding and capacitive loading. The antenna operates in the frequency band of 0.8-5 GHz and has dimensions of 0.55 × 0.13 × 0.01λ. l 3 It features wide bandwidth coverage and low profile, and its structure is as follows: Figures 1 to 6 As shown, it includes a dipole antenna 1 and a Wilkinson power divider 2. The dipole antenna 1 and the Wilkinson power divider 2 are connected by two symmetrically placed coaxial cables 1-17, wherein: The dipole antenna 1 includes a first dielectric substrate 1-7 and a metal radiating patch structure mounted on the first dielectric substrate 1-7. The Wilkinson power divider 2 includes a second dielectric substrate 2-10 and a power divider, microstrip line, isolation resistor 2-9 and metal ground plane 2-11 mounted on the second dielectric substrate 2-10; The dipole antenna 1 and Wilkinson power divider 2 are printed on single-layer PCB dielectric substrates 1-7 and 2-10, with a dielectric constant of 2.55 and thicknesses of 3.8 mm and 0.762 mm, respectively.

[0021] The dipole antenna 1 adopts a wide-arm structure and combines it with a loaded capacitor structure to achieve mode compression and bandwidth expansion; the Wilkinson power divider 2 is based on the impedance transformation characteristics of the λ / 4 transmission line. It divides the input signal into two equal paths through two branches with the same impedance, and outputs two signals with equal amplitude and the same phase. The two output terminals are respectively connected to the two symmetrical feed points of the dipole antenna 1 through corresponding coaxial cables 1-17 to achieve dual-point symmetrical feeding.

[0022] Specifically, such as Figure 2 and Figure 3As shown, the metal radiating patch structure includes a first metal radiating patch 1-1, a second metal radiating patch 1-2, a third metal radiating patch 1-3, a fourth metal radiating patch 1-4, a fifth metal radiating patch 1-5, a sixth metal radiating patch 1-6, chamfers A1-8, B1-9, C1-10, and D1-11, gaps A1-12, B1-13, and C1-14, wherein: like Figure 4 As shown, the first metal radiation patch 1-1 and the second metal radiation patch 1-2, the third metal radiation patch 1-3 and the fourth metal radiation patch 1-4, and the fifth metal radiation patch 1-5 and the sixth metal radiation patch 1-6 are all mirror-symmetrical. The first metal radiating patch 1-1 and the third metal radiating patch 1-3 are fitted with chamfers A1-8 and B1-9, respectively. The second metal radiating patch 1-2 and the fourth metal radiating patch 1-4 are fitted with chamfers C1-10 and D1-11, respectively. The rectangular patch has a length of (L4+L5) and a width of W2. Chamfer A has a length of L4 and a width of (W2-W3) / 2. Chamfers A1-8 and B1-9 are symmetrical along the Y-axis. The third metal radiating patch 1-3 is a rectangular patch with chamfers C1-10 and D1-11. The rectangular patch has a length of (L2+L3) and a width of W2. Chamfer C1-10 has a length of L3 and a width of (W2-W3) / 2. Chamfers C1-10 and D1-11 are symmetrical along the Y-axis. The fifth metal radiating patch 1-5 is a rectangular patch with a length of L1 and a width of W1.

[0023] A1-12 is loaded between the first metal radiating patch 1-1 and the second metal radiating patch 1-2; B1-13 is loaded between the first metal radiating patch 1-1 and the third metal radiating patch 1-3, and between the second metal radiating patch 1-2 and the fourth metal radiating patch 1-4. Gap C1-14 is loaded between the third metal radiating patch 1-3 and the fifth metal radiating patch 1-5, and between the fourth metal radiating patch 1-4 and the sixth metal radiating patch 1-6. Gap A1-12, gap B1-13 and gap C1-14 form a capacitive loading structure. As a transverse gap, the capacitive loading structure introduces capacitive characteristics, causing the overall resonant point of the dipole antenna 1 to shift towards the high frequency direction. Furthermore, the wide-arm structure formed by the first to sixth metal radiating patches extends the current path and expands the low-frequency bandwidth.

[0024] A gap A1-12 with a width of W is provided between the first metal radiating patch 1-1 and the second metal radiating patch 1-2. slot1 ; A gap B1-13 with a width of W is provided between the first metal radiating patch 1-1 and the third metal radiating patch 1-3, and between the second metal radiating patch 1-2 and the fourth metal radiating patch 1-4. slot3 ; A gap C1-14, with a width of W, is provided between the third metal radiation patch 1-3 and the fifth metal radiation patch 1-5, and between the fourth metal radiation patch 1-4 and the sixth metal radiation patch 1-6. slot2 ; The length of the first dielectric substrate 1-7 is L sub Width is W sub ; More specifically, the first dielectric substrate 1-7 is provided with a first metal through-hole 1-15 and a second metal through-hole 1-16, wherein: The first metal through hole 1-15 is connected to the second metal radiating patch 1-2, the fourth metal radiating patch 1-4 and the inner conductors of the two coaxial cables 1-17 respectively, and the length Hsub is the same as the thickness of the first dielectric substrate 1-7. The second metal through-hole 1-16 is connected to the outer conductors of the first metal radiating patch 1-1, the third metal radiating patch 1-3, and the two coaxial cables 1-17, respectively, and the length Hsub is the same as the thickness of the first dielectric substrate 1-7.

[0025] Furthermore, such as Figure 5 As shown, for the Wilkinson power divider 2, the power divider includes a first Wilkinson power divider 2-1, a second Wilkinson power divider 2-2, a third Wilkinson power divider 2-3, a fourth Wilkinson power divider 2-4, a fifth Wilkinson power divider 2-5, and a sixth Wilkinson power divider 2-6; the microstrip line includes microstrip line A2-7 and microstrip line B2-8, wherein: The input terminal of the first Wilkinson power divider 2-1 is a signal input port, and its two output terminals are connected to the second Wilkinson power divider 2-2. The Wilkinson power dividers of each stage are connected in sequence, that is, the two output terminals of the second Wilkinson power divider 2-2 are connected to the third Wilkinson power divider 2-3, the two output terminals of the third Wilkinson power divider 2-3 are connected to the fourth Wilkinson power divider 2-4, the two output terminals of the fourth Wilkinson power divider 2-4 are connected to the fifth Wilkinson power divider 2-5, and the two output terminals of the fifth Wilkinson power divider 2-5 are connected to the sixth Wilkinson power divider 2-6. Each Wilkinson power divider has two branch lines and an isolation resistor of 2-9 is provided between the two branch lines; The two output terminals of the sixth Wilkinson power divider 2-6 output signals of equal amplitude and in phase, which are respectively connected to microstrip line A2-7 and microstrip line B2-8. The Wilkinson power divider 2 is connected to two 50Ω coaxial cables 1-17 via microstrip lines A2-7 and B2-8 to provide dual-point feeding for the dipole antenna 1. The metal floor 2-11 is disposed on the reverse side of the second dielectric substrate 2-10, and each Wilkinson power divider is disposed on the front side of the second dielectric substrate 2-10.

[0026] like Figure 6 As shown, the input port microstrip line width of the Wilkinson power divider 2 is Wd8. The first Wilkinson power divider 2-1 has a length of 2Ld9 and a width of Wd7. The second Wilkinson power divider 2-2 has a length of 2Ld8 and a width of Wd6. The third Wilkinson power divider 2-3 has a length of 2Ld7 and a width of Wd5. The fourth Wilkinson power divider 2-4 has a length of 2Ld6 and a width of Wd4. The fifth Wilkinson power divider 2-5 has a length of 2Ld5 and a width of Wd3. The sixth Wilkinson power divider 2-6 has a length of 2Ld4 and a width of Wd2. Microstrip line A2-7 has a length of (Ld2 + Ld3) and a width of Wd1. Microstrip line B2-8 has a length of (Ld2 + Ld3) and a width of Wd1. Additionally, the output port spacing of the Wilkinson power divider 2 is Ld1.

[0027] Furthermore, the Wilkinson power divider 2 adopts a sixth-order Wilkinson power divider form, with the branch line length of each order Wilkinson power divider being close to 0.25λ0, where λ0 is the wavelength corresponding to the center operating frequency of the antenna element. Each Wilkinson power divider consists of a ring structure composed of bent microstrip lines, and the bends of the bent microstrip lines are chamfered to reduce signal reflection and improve overall impedance matching; the widths of the fifth metal radiating patch 1-5 and the sixth metal radiating patch 1-6 are slightly smaller than those of the other metal radiating patches. Resistors 2-9 are located between the two branches of each Wilkinson power divider and include six resistors with resistance values ​​of R1, R2, R3, R4, R5, and R6. Isolation resistors 2-9 with values ​​of 100Ω, 120Ω, 220Ω, 330Ω, 470Ω, and 680Ω are sequentially placed between the two branches of each Wilkinson power divider.

[0028] The second dielectric substrate 2-10 and the metal ground plane 2-11 have the same lateral dimension, both being 100×48mm. 2 .

[0029] In this embodiment, the specific dimension is: L sub =230mm, H sub =3.8mm, W sub=70mm, L1=43mm, W1=28mm, L2=44mm, W2=26.5mm, L3=13mm, W3=11mm, L4=13mm, L5=13.75, W slot1 =2.5mm, W slot2 =1mm, W slot3 =1mm, Ld1=56.1mm, Wd1=2.1mm, Ld2=10mm, Wd2=1.78mm, Ld3=27.6mm, Wd3=1.5mm, Ld4=20.6mm, Wd4=1.27mm, Ld5=18.5mm, Wd5=0.96mm, Ld6 =18.5mm, Wd6=0.81mm, Ld7=17.5mm, Wd7=0.65mm, Ld8=18.5mm, Wd8=2.1mm, Ld9=, R1=680Ω, R2=470Ω, R3=330Ω, R4=220Ω, R5=120Ω, R6=100Ω.

[0030] Figure 7 The |S| of the ultrawideband dipole antenna based on dual-point feeding and capacitive loading of the present invention is... 11 Simulation results and gain simulation results show that the voltage standing wave ratio (VSWR) is less than 2 within the 0.79-5 GHz range, and the relative bandwidth is 145.2%, indicating that the antenna has wide bandwidth coverage and good impedance matching. Meanwhile, the gain ranges from 0.3 to 4.3 dBi within the operating frequency band, and the overall gain is relatively stable, demonstrating high gain characteristics.

[0031] Figure 8 The simulation results of the E-plane and H-plane radiation patterns of this invention at (a) 0.9 GHz, (b) 2.1 GHz, (c) 3.2 GHz, (d) 4.2 GHz, and (e) 5 GHz are shown. The ultra-wideband dipole antenna designed in this invention has a symmetrical radiation pattern in the E-plane with no dip in the main radiation direction; the radiation pattern in the H-plane has good omnidirectionality with a non-circularity of less than 4 dBi. This antenna has stable radiation performance, wide coverage, and excellent omnidirectional radiation characteristics.

[0032] It is worth mentioning that the technical features such as resistors involved in this patent application should be regarded as prior art. The specific structure, working principle, and possible control methods and spatial arrangement of these technical features can be adopted using conventional choices in the field, and should not be regarded as the inventive point of this patent. This patent will not be further elaborated in detail.

[0033] For those skilled in the art, modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the protection scope of this invention.

Claims

1. An ultrawideband omnidirectional dipole antenna based on dual-point feeding and capacitive loading, characterized in that, It includes a dipole antenna (1) and a Wilkinson power divider (2), wherein the dipole antenna (1) and the Wilkinson power divider (2) are connected by two symmetrically placed coaxial cables (1-17), wherein: The dipole antenna (1) includes a first dielectric substrate (1-7) and a metal radiating patch structure mounted on the first dielectric substrate (1-7); The Wilkinson power divider (2) includes a second dielectric substrate (2-10) and a power divider, microstrip line, isolation resistor (2-9) and metal ground plane (2-11) mounted on the second dielectric substrate (2-10). The dipole antenna (1) adopts a wide-arm structure and combines a loaded capacitor structure to achieve mode compression and bandwidth expansion; the Wilkinson power divider (2) is based on impedance transformation characteristics, and divides the input signal into two equal paths through two branches with the same impedance, outputting two signals with equal amplitude and the same phase, and the two output terminals are respectively connected to the two symmetrical feed points of the dipole antenna (1) through corresponding coaxial cables (1-17) to achieve dual-point symmetrical feeding.

2. The ultra-wideband omnidirectional dipole antenna based on dual-point feeding and capacitive loading according to claim 1, characterized in that, The metal radiating patch structure includes a first metal radiating patch (1-1), a second metal radiating patch (1-2), a third metal radiating patch (1-3), a fourth metal radiating patch (1-4), a fifth metal radiating patch (1-5), a sixth metal radiating patch (1-6), chamfer A (1-8), chamfer B (1-9), chamfer C (1-10), chamfer D (1-11), gap A (1-12), gap B (1-13), and gap C (1-14), wherein: The first metal radiation patch (1-1) and the second metal radiation patch (1-2), the third metal radiation patch (1-3) and the fourth metal radiation patch (1-4), and the fifth metal radiation patch (1-5) and the sixth metal radiation patch (1-6) are all mirror-symmetrical. The first metal radiation patch (1-1) and the third metal radiation patch (1-3) are loaded with chamfer A (1-8) and chamfer B (1-9), and the second metal radiation patch (1-2) and the fourth metal radiation patch (1-4) are loaded with chamfer C (1-10) and chamfer D (1-11). A gap A (1-12) is loaded between the first metal radiation patch (1-1) and the second metal radiation patch (1-2); a gap B (1-13) is loaded between the first metal radiation patch (1-1) and the third metal radiation patch (1-3), and between the second metal radiation patch (1-2) and the fourth metal radiation patch (1-4). Gap C (1-14) is loaded between the third metal radiating patch (1-3) and the fifth metal radiating patch (1-5), and between the fourth metal radiating patch (1-4) and the sixth metal radiating patch (1-6). Gap A (1-12), gap B (1-13) and gap C (1-14) form a capacitive loading structure. As a transverse gap, the capacitive loading structure introduces capacitive characteristics, causing the overall resonant point of the dipole antenna (1) to shift towards the high frequency direction. Furthermore, through the wide arm structure formed by the first to sixth metal radiating patches, the current path is extended and the low frequency bandwidth is expanded.

3. The ultra-wideband omnidirectional dipole antenna based on dual-point feeding and capacitive loading according to claim 2, characterized in that, The first dielectric substrate (1-7) is provided with a first metal through-hole (1-15) and a second metal through-hole (1-16), wherein: The first metal through hole (1-15) is connected to the inner conductors of the second metal radiating patch (1-2), the fourth metal radiating patch 1-4 and the two coaxial cables (1-17), respectively, and its length is the same as the thickness of the first dielectric substrate (1-7). The second metal through hole (1-16) is connected to the outer conductors of the first metal radiating patch (1-1), the third metal radiating patch (1-3), and the two coaxial cables (1-17), respectively, and its length is the same as the thickness of the first dielectric substrate (1-7).

4. The ultra-wideband omnidirectional dipole antenna based on dual-point feeding and capacitive loading according to claim 3, characterized in that, For the Wilkinson power divider (2), the power divider includes a first Wilkinson power divider (2-1), a second Wilkinson power divider (2-2), a third Wilkinson power divider (2-3), a fourth Wilkinson power divider (2-4), a fifth Wilkinson power divider (2-5), and a sixth Wilkinson power divider (2-6); the microstrip line includes microstrip line A (2-7) and microstrip line B (2-8), wherein: The input terminal of the first Wilkinson power divider (2-1) is the signal input port, and the two output terminals are connected to the second Wilkinson power divider (2-2). The Wilkinson power dividers of each stage are connected in sequence. Each Wilkinson power divider has two branch lines and an isolation resistor (2-9) between the two branch lines. The two output terminals of the sixth Wilkinson power divider (2-6) output signals of equal amplitude and in phase, which are respectively connected to microstrip line A (2-7) and microstrip line B (2-8). The Wilkinson power divider (2) is connected to two coaxial cables (1-17) via microstrip line A (2-7) and microstrip line B (2-8) to provide dual-point feeding for the dipole antenna (1); The metal floor (2-11) is disposed on the reverse side of the second dielectric substrate (2-10).

5. An ultra-wideband omnidirectional dipole antenna based on dual-point feeding and capacitive loading according to claim 4, characterized in that, The Wilkinson power divider (2) adopts the form of a sixth-order Wilkinson power divider. The branch line length of each order of Wilkinson power divider is close to 0.25λ0, where λ0 is the wavelength corresponding to the center operating frequency of the antenna element. All Wilkinson power dividers are composed of a ring structure made of bent microstrip lines, and the bends of the bent microstrip lines are chamfered. Isolation resistors of 100Ω, 120Ω, 220Ω, 330Ω, 470Ω, and 680Ω are set between the two branches of each Wilkinson power divider (2-9).

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