A non-periodic non-uniform slot capacitively loaded ring type broadband horizontally polarized omnidirectional antenna

Abstract

The application discloses a kind of based on non-periodic non-uniform gap capacitance loading ring type broadband horizontal polarization omnidirectional antenna, including first dielectric substrate, single loop radiation patch, first feed port and impedance matching line, single loop radiation patch is set on the upper surface of first dielectric substrate, and first feed port is fed to single loop radiation patch by impedance matching line;Single loop radiation patch is non-periodic non-uniform gap capacitance loading structure, and the non-periodic non-uniform gap capacitance loading structure is obtained by cutting gap in the direction of loop close to first feed port on circular ring transmission line, and the radian of each gap cut is different;The gap cut is equivalent to introducing series capacitance on circular ring transmission line, by introducing series capacitance, the current phase and current direction on single loop radiation patch remain unchanged, and horizontal polarization omnidirectional radiation mode is obtained.

Description

Technical Field

[0001] This invention relates to the field of antennas in communication technology, and specifically to a ring-shaped broadband horizontally polarized omnidirectional antenna based on non-periodic non-uniform slot capacitance loading. Background Technology

[0002] An antenna is a wireless device used to transmit and receive electromagnetic waves, playing a crucial role in communication systems. In practical applications, different communication environments have different requirements for antennas. Directional antennas can only radiate in a specific direction, while omnidirectional antennas can radiate 360° within the azimuth plane. Omnidirectional antennas are required in many wireless communication systems, such as wireless local area networks (WLANs), base stations, and portable devices. Omnidirectional antennas are divided into vertically polarized omnidirectional antennas and horizontally polarized omnidirectional antennas. Horizontally polarized omnidirectional antennas can be used in urban or indoor wireless communication environments because the polarization characteristics of electromagnetic waves propagating in such environments change after complex multiple reflections or scatterings. Vertically polarized waves are more susceptible to these environmental influences than horizontally polarized waves. Therefore, horizontally polarized omnidirectional antennas are commonly used in television broadcasting communication systems, and they are also widely used in mobile phones, tablets, and laptops.

[0003] With the rapid development of 5G / 6G communication, scenarios where multiple wireless communication systems coexist will persist for a long time. Achieving broadband and miniaturized antenna design can save base station resources and costs. Currently, the design of narrowband horizontally polarized omnidirectional antennas is very mature and diverse. However, some problems and challenges remain in the design of broadband horizontally polarized omnidirectional antennas. Among these, antenna bandwidth and size are a design contradiction, with size including both the overall structural dimensions and the cross-sectional dimensions. Currently, horizontally polarized omnidirectional antennas with simple structures and low cross-sections have relatively small operating bandwidths, while those with larger bandwidths are typically larger and more complex in structure and feeding network. Given the current communication environment, designing high-performance horizontally polarized omnidirectional antennas not only has significant academic value but also important engineering application significance.

[0004] The main drawbacks of existing technologies are as follows:

[0005] (1) Most horizontally polarized omnidirectional antennas realized by electric dipole array are three-dimensional structures with high profiles, large space requirements, and high processing costs.

[0006] (2) The profile of the horizontally polarized omnidirectional antenna achieved by the combined loop antenna structure is relatively low, but the bandwidth is narrow.

[0007] (3) Existing horizontally polarized omnidirectional antennas are difficult to achieve simultaneously with large bandwidth, small size, simple structure and feeding network, which limits the application of horizontally polarized omnidirectional antennas in wireless communication systems.

[0008] Therefore, it is necessary to study a horizontally polarized omnidirectional antenna with large bandwidth, small size and easy manufacturing. Summary of the Invention

[0009] Purpose of the invention: To address the problems of large overall size and complex structure of existing broadband horizontally polarized omnidirectional antennas, this invention proposes a ring-shaped broadband horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading, which can simultaneously achieve large bandwidth, small overall size and simple structure, and can be used in wireless communication and other fields.

[0010] Technical solution: A ring-shaped broadband horizontally polarized omnidirectional antenna based on non-periodic non-uniform slot capacitance loading, comprising a first dielectric substrate, a single-ring radiating patch, a first feed port, and an impedance matching line. The single-ring radiating patch is disposed on the upper surface of the first dielectric substrate, and the first feed port feeds the single-ring radiating patch through the impedance matching line.

[0011] The single-ring radiating patch is an aperiodic non-uniform slot capacitive loading structure. The aperiodic non-uniform slot capacitive loading structure is obtained by aperiodicly cutting slots along the loop direction near the first feed port on the circular transmission line, and the curvature of each cut slot is different.

[0012] The cut gap is equivalent to introducing a series capacitor on the circular transmission line. By introducing the series capacitor, the current phase and current direction on the single-ring radiating patch remain unchanged, thus obtaining a horizontally polarized omnidirectional radiation mode.

[0013] Furthermore, by changing the curvature of the gap, the antenna resonant frequency and impedance matching effect can be adjusted, thereby increasing the antenna bandwidth.

[0014] Furthermore, both the first power supply port and the impedance matching line are located inside the single-ring radiating patch.

[0015] Furthermore, by adjusting the length and width of the impedance matching line, the impedance matching between the first feed port and the single-ring radiating patch can be adjusted.

[0016] The present invention also discloses a ring-shaped broadband horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading, comprising a second dielectric substrate, an outer ring radiating patch, an inner ring radiating patch, and a second feed port; the outer ring radiating patch, the inner ring radiating patch, and the second feed port are all located on the upper surface of the second dielectric substrate, the inner ring radiating patch is disposed inside the outer ring radiating patch as a parasitic ring, and the second feed port directly feeds the outer ring radiating patch and coupled to feed the inner ring radiating patch;

[0017] The outer ring radiating patch is an aperiodic, non-uniform slot capacitor loading structure. The aperiodic, non-uniform slot capacitor loading structure is obtained by making aperiodic cuts along the loop direction near the second feed port on the circular transmission line, with each cut having a different arc. The cuts are equivalent to introducing series capacitors on the circular transmission line. By introducing series capacitors, the current phase and current direction on the outer ring radiating patch remain unchanged, thus obtaining a horizontally polarized omnidirectional radiation mode.

[0018] The arc and position of the slits cut on the inner ring radiating patch correspond to the arc and position of the slits cut on the outer ring radiating patch, thus forming horizontally polarized omnidirectional radiation while adjusting the impedance matching of the antenna.

[0019] Furthermore, the resonant frequency and impedance matching of the antenna can be adjusted by changing the curvature of the gap, the width of the outer ring radiating patch, and the width of the inner ring radiating patch.

[0020] Furthermore, by adjusting the radius and width of the outer and inner ring radiating patches, the resonant points of the outer and inner ring radiating patches are brought closer to each other, thereby expanding the antenna bandwidth.

[0021] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0022] (1) Based on the non-periodic non-uniform slot capacitor loading structure, this invention proposes a single-ring broadband horizontally polarized omnidirectional antenna, which can simultaneously achieve the advantages of broadband, small overall size, simple structure and simple feeding.

[0023] (2) Based on the non-periodic non-uniform slot capacitor loading structure, the present invention proposes a dual-ring bandwidth horizontal polarization omnidirectional antenna. By loading a parasitic ring inside the single-ring broadband horizontal polarization omnidirectional antenna based on non-periodic non-uniform slot capacitor loading, the bandwidth of the antenna can be further increased and the feeding structure can be simplified.

[0024] (3) Based on the non-periodic non-uniform slot capacitor loading structure, the present invention solves the problems of large overall size and complex structure of existing broadband horizontal polarization omnidirectional antennas. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the single-ring broadband horizontally polarized omnidirectional antenna based on aperiodic, non-uniform slot capacitance loading proposed in this invention; wherein, Figure 1 (a) in the figure is the overall structure diagram of a single-loop broadband horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading. Figure 1 Image (b) is a side view of a single-loop broadband horizontally polarized omnidirectional antenna based on aperiodic, non-uniform slot capacitance loading. Figure 1(c) in the figure is a front view of the first dielectric substrate. Figure 1 (d) in the figure is a rear view of the first dielectric substrate;

[0026] Figure 2 The surface current distribution on the single-loop broadband horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in this invention is shown at 2.8 GHz, 3.3 GHz, 3.8 GHz, 4.3 GHz, 4.8 GHz, and 5.3 GHz.

[0027] Figure 3 The S-parameter diagram of the single-loop broadband horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in this invention is shown.

[0028] Figure 4 This is the electric field pattern of the single-loop broadband horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in this invention, operating at 2.8 GHz; wherein, Figure 4 (a) in the diagram represents the XOY plane. Figure 4 (b) in the diagram represents the YOZ plane;

[0029] Figure 5 This is the electric field pattern of the single-loop broadband horizontally polarized omnidirectional antenna based on aperiodic, non-uniform slot capacitance loading proposed in this invention, operating at 3.3 GHz; wherein, Figure 5 (a) in the diagram represents the XOY plane. Figure 5 (b) in the diagram represents the YOZ plane;

[0030] Figure 6 This is the electric field pattern of the single-loop broadband horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in this invention when operating at 3.8 GHz; wherein, Figure 6 (a) in the diagram represents the XOY plane; Figure 6 (b) in the diagram represents the YOZ plane;

[0031] Figure 7 This is the electric field pattern of the single-loop broadband horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in this invention when operating at 4.3 GHz; wherein, Figure 7 (a) in the diagram represents the XOY plane; Figure 7 (b) in the diagram represents the YOZ plane;

[0032] Figure 8 This is the electric field pattern of the single-loop broadband horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in this invention when operating at 4.8 GHz; wherein, Figure 8 (a) in the diagram represents the XOY plane; Figure 8 (b) in the diagram represents the YOZ plane;

[0033] Figure 9 This is the electric field pattern of the single-loop broadband horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in this invention when operating at 5.3 GHz; wherein, Figure 9 (a) in the diagram represents the XOY plane; Figure 9 (b) in the diagram represents the YOZ plane;

[0034] Figure 10 This is a structural diagram of a horizontally polarized omnidirectional antenna based on periodic uniform slot capacitance loading.

[0035] Figure 11 The S-parameters of a horizontally polarized omnidirectional antenna based on periodic uniform slot capacitance loading are given.

[0036] Figure 12 This is a schematic diagram of the structure of the dual-ring bandwidth horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in this invention; wherein, Figure 12 (a) in the diagram is the overall structure of a dual-ring bandwidth horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading. Figure 12 Image (b) is a side view of a dual-loop bandwidth horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading. Figure 12 (c) in the figure is a front view of the second dielectric substrate. Figure 12 (d) in the figure is a rear view of the second dielectric substrate;

[0037] Figure 13 The S-parameter diagram of the dual-ring bandwidth horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in this invention is shown.

[0038] Figure 14 This is the electric field pattern of the dual-ring bandwidth horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in this invention, operating at 2.85 GHz; wherein, Figure 14 (a) in the diagram represents the XOY plane. Figure 14 (b) in the diagram represents the YOZ plane;

[0039] Figure 15 This is the electric field pattern of the dual-ring bandwidth horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in this invention when operating at 3.35 GHz; wherein, Figure 15 (a) in the diagram represents the XOY plane. Figure 15 (b) in the diagram represents the YOZ plane;

[0040] Figure 16 This is the electric field pattern of the dual-ring bandwidth horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in this invention when operating at 3.85 GHz; wherein, Figure 16 (a) in the diagram represents the XOY plane. Figure 16(b) in the diagram represents the YOZ plane;

[0041] Figure 17 This is the electric field pattern of the dual-ring bandwidth horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in this invention when operating at 4.35 GHz; wherein, Figure 17 (a) in the diagram represents the XOY plane. Figure 17 (b) in the diagram represents the YOZ plane;

[0042] Figure 18 This is the electric field pattern of the dual-ring bandwidth horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in this invention when operating at 4.85 GHz; wherein, Figure 18 (a) in the diagram represents the XOY plane. Figure 18 (b) in the diagram represents the YOZ plane;

[0043] Figure 19 This is the electric field pattern of the dual-ring bandwidth horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in this invention when operating at 5.35 GHz; wherein, Figure 19 (a) in the diagram represents the XOY plane. Figure 19 (b) in the diagram represents the YOZ plane;

[0044] Figure 20 This is the electric field pattern of the dual-ring bandwidth horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in this invention when operating at 5.85 GHz; wherein, Figure 20 (a) in the diagram represents the XOY plane. Figure 20 (b) in the diagram represents the YOZ plane;

[0045] Figure 21 This is the electric field pattern of the dual-ring bandwidth horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in this invention when operating at 6.35 GHz; wherein, Figure 21 (a) in the diagram represents the XOY plane. Figure 21 (b) in the diagram represents the YOZ plane;

[0046] Figure 22 This is the electric field pattern of the dual-ring bandwidth horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in this invention when operating at 6.85 GHz; wherein, Figure 22 (a) in the diagram represents the XOY plane. Figure 22 (b) in the diagram represents the YOZ plane. Detailed Implementation

[0047] The technical solution of the present invention will now be further described in conjunction with the accompanying drawings and embodiments.

[0048] This embodiment discloses a single-loop broadband horizontally polarized omnidirectional antenna based on aperiodic, non-uniform slot capacitance loading, such as... Figure 1 As shown in (a) and (b), the antenna includes a first dielectric substrate 1, a single-ring radiating patch 2, a first feed port 3, and an impedance matching line 4. The single-ring radiating patch 2 is disposed on the upper surface of the first dielectric substrate 1, and the lower surface of the first dielectric substrate 1 is unstructured. The first feed port 3 uses an SMA coaxial interface with a characteristic impedance of 50 ohms to feed the single-ring radiating patch 2 through the impedance matching line 4.

[0049] In this embodiment, the single-ring radiating patch 2 is a circular segmented line structure. This circular segmented line structure is obtained by cutting gaps in the circular transmission line. The position of the gaps on the single-ring radiating patch 2 is a non-periodic cut along the loop direction close to the first feed port 3, and the curvature of the gaps is designed to have different values, thus forming a non-periodic non-uniform gap capacitor loading structure.

[0050] The cut gap can be equivalent to introducing a series capacitor on the circular transmission line. The series capacitor can compensate for the phase shift along the circular transmission line to reduce the phase lag of the current, so that the current phase and current direction on the single-ring radiating patch 2 remain unchanged, and a horizontally polarized omnidirectional radiation mode is obtained.

[0051] The single-ring radiating patch 2 has a left-right symmetrical structure. The introduced series capacitor is designed to be loaded non-periodically along the loop. The arc of the slits cut on each segment line is designed to be different to adjust the resonant frequency and impedance matching of the antenna, thereby increasing the bandwidth of the antenna and designing a small-sized broadband horizontally polarized omnidirectional antenna.

[0052] The non-periodic loading will now be explained in more detail.

[0053] Along the loop direction near the first feed port 3, the curvature of each segment line gradually increases. Therefore, the position of the slot cut in the loop is aperiodic, forming an aperiodic slot capacitor loading structure. The aperiodic slot capacitor loading structure is beneficial for adjusting the impedance matching of the antenna and increasing the bandwidth of the antenna.

[0054] The following explanation further details how different values ​​are used to design the arc of the slits cut on each segment line to adjust the resonant frequency and impedance matching of the antenna.

[0055] The arc value of the slit cut along the loop direction near the first feed port 3 is also different, forming an aperiodic non-uniform slit capacitor loading structure. By changing the arc of the slit, the value of the equivalent series capacitance on the circular transmission line can be changed, which is used to adjust the antenna resonant frequency and the antenna impedance matching effect, and increase the antenna bandwidth.

[0056] In this embodiment, the first impedance matching line 4 is a pair of impedance matching striplines, which are directly connected to the single-ring radiating patch 2. By adjusting the length and width of the impedance matching line 4, the impedance matching between the first feed port 3 and the single-ring radiating patch 2 can be adjusted. The entire feed structure is located within the internal space of the single-ring broadband horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading, making the antenna structure simple and compact.

[0057] like Figure 2 As shown in (a) to (f) of the figure, the surface current distribution of the single-loop broadband horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in this embodiment is as follows when it operates sequentially at 2.8 GHz, 3.3 GHz, 3.8 GHz, 4.3 GHz, 4.8 GHz, and 5.3 GHz. It can be seen from the figures that when the antenna of this embodiment operates near the 2.8 GHz-3.8 GHz frequency band, the surface current of the single-loop radiating patch 2 is distributed in the same direction; when the antenna of this embodiment operates near the 3.8 GHz-4.8 GHz frequency band, the surface current of the single-loop radiating patch 2 shows a small reverse direction near the first feed port 3, but overall the current can be considered to be distributed in the same direction; when the antenna of this embodiment operates near 5.3 GHz, the currents in the upper and lower half-loops of the single-loop radiating patch 2 are in opposite directions, resulting in slightly poor omnidirectionality of the horizontal plane (XOY plane) radiation pattern.

[0058] Figure 3 The S-parameter curves of the single-ring broadband horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in this embodiment are shown below. Figure 3 As can be seen, the -10 dB impedance bandwidth of the antenna in this embodiment is 2.82 GHz (2.60-5.42 GHz), and the relative bandwidth is 70.3%.

[0059] like Figure 4 ~ Figure 9 The figures show the electric field patterns of the antenna in this embodiment when it operates at 2.8 GHz, 3.3 GHz, 3.8 GHz, 4.3 GHz, 4.8 GHz, and 5.3 GHz, respectively. It can be seen that the antenna in this embodiment exhibits good omnidirectional radiation patterns at 2.8 GHz, 3.3 GHz, 3.8 GHz, 4.3 GHz, and 4.8 GHz, generally maintaining horizontally polarized omnidirectional radiation. However, the omnidirectionality slightly deteriorates when the antenna operates near 5.3 GHz.

[0060] Therefore, the single-loop broadband horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in this embodiment can simultaneously meet the application requirements of broadband and low profile, with an overall size of 0.75×0.75×0.01. The relative bandwidth is 70.3%.

[0061] To further illustrate the advantages of the single-loop broadband horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading obtained by implementing multiple technologies in this embodiment, a model is now constructed as follows: Figure 10 The diagram shows a structure of a horizontally polarized omnidirectional antenna based on periodic uniform slot capacitance loading. It also consists of a first dielectric substrate 1, a single-ring radiating patch 2, a first feed port 3, and an impedance matching line 4. Figure 10 As shown in (b), the gap positions on the single-ring radial patch 2 are periodic, meaning the positions of the loaded capacitors are periodic, and the curvature of the gaps is the same. Figure 11 The S-parameter curve shows that this horizontally polarized omnidirectional antenna based on periodically uniform slot capacitance loading has a -10 dB impedance bandwidth of 1.2 GHz (2.65-3.85 GHz) and a relative bandwidth of 40%. This is compared to... Figure 3 and Figure 11 It can be seen that non-periodic, non-uniformly loaded slot capacitance can significantly increase the bandwidth of a single-loop horizontally polarized omnidirectional antenna.

[0062] Compared with the single-loop broadband horizontally polarized omnidirectional antenna based on aperiodic and non-uniform slot capacitance loading proposed in this embodiment, the relative bandwidth of the constructed horizontally polarized omnidirectional antenna based on periodic uniform slot capacitance loading is increased from 40% to 70.3%.

[0063] This embodiment proposes a dual-ring bandwidth horizontally polarized omnidirectional antenna based on aperiodic, non-uniform slot capacitance loading, such as... Figure 12 As shown in (a) and (b), the antenna includes: a second dielectric substrate 5, an outer ring radiating patch 6, an inner ring radiating patch 7, and a second feed port 8; the second feed port 8 uses an SMA coaxial interface with a characteristic impedance of 50 ohms to directly feed the outer ring radiating patch 6 and to couple the feed to the inner ring radiating patch 7. Figure 12 As shown in (c) and (d), the outer ring radiating patch 6, the inner ring radiating patch 7, and the second power supply port 8 are all located on the upper surface of the second dielectric substrate 5, and the lower surface of the second dielectric substrate 5 has no structure.

[0064] In this embodiment, both the outer ring radiating patch 6 and the inner ring radiating patch 7 are aperiodic, non-uniform slot capacitor loading structures, and are symmetrical. This aperiodic, non-uniform slot capacitor loading structure is obtained by cutting slots in a circular transmission line. The slots on the outer ring radiating patch 6 are cut aperiodically along the loop direction near the second feed port 8, and the arc of the slots is designed to have different values, allowing the arc of each segment to gradually increase. By introducing series capacitors through slots in the circular transmission line, the phase lag of the current on the radiating patch is reduced, resulting in the current being distributed in the same direction on the dual-ring bandwidth horizontally polarized omnidirectional antenna based on aperiodic, non-uniform slot capacitor loading, thus obtaining a horizontally polarized omnidirectional radiation mode. The arc and position of the slots cut in the inner ring radiating patch 7 correspond to the arc and position of the slots cut in the outer ring radiating patch 6, forming horizontally polarized omnidirectional radiation while adjusting the antenna impedance matching.

[0065] A challenge in the design of horizontally polarized omnidirectional antennas is how to achieve both high bandwidth and miniaturization using a simple structure. This embodiment presents a multi-ring structure obtained by combining two non-periodic, non-uniform slot capacitively loaded radiating patches, where the inner ring radiating patch 7 acts as a parasitic ring. This structure can significantly increase the antenna's bandwidth, and by changing the arc of the slots and the widths of the inner and outer rings, the resonant frequency and impedance matching of the antenna can be adjusted together, while simultaneously reducing the overall size of the antenna.

[0066] Because the outer ring radiating patch 6 and the inner ring radiating patch 7 have different radii, they can operate in different frequency bands. By adjusting the radii and widths of the inner and outer rings, the resonant points of the two rings can be brought closer together, thereby further extending the antenna bandwidth. In this embodiment, a parasitic ring is loaded inside a single-ring broadband horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading, thereby further increasing the antenna bandwidth and simplifying the feeding structure.

[0067] Figure 13 The S-parameter curves of a dual-ring bandwidth horizontally polarized omnidirectional antenna based on aperiodic, non-uniform slot capacitance loading are shown below. Figure 13 As can be seen, the -10 dB impedance bandwidth of the antenna in this embodiment is 4 GHz (2.85-6.85 GHz), and the relative bandwidth is 82.5%.

[0068] like Figure 14 ~ Figure 22As shown, the electric field patterns of the antenna in this embodiment are displayed sequentially at 2.85 GHz, 3.35 GHz, 3.85 GHz, 4.35 GHz, 4.85 GHz, 5.35 GHz, 5.85 GHz, 6.35 GHz, and 6.85 GHz. It can be seen that the antenna in this embodiment maintains good horizontal polarization radiation at these frequencies. The omnidirectionality of the (XOY plane) pattern is well maintained at the lower frequencies of 2.85 GHz, 3.35 GHz, 3.85 GHz, and 4.35 GHz, but deteriorates slightly at higher frequencies. The dual-loop broadband horizontally polarized omnidirectional antenna based on aperiodic non-uniform capacitor loading proposed in this embodiment can simultaneously meet the application requirements of broadband and low profile, with an overall size of 0.97 × 0.97 × 0.01 mm. The relative bandwidth is 82.5%.

[0069] The single-loop broadband horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in Embodiment 1, and the double-loop broadband horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading proposed in Embodiment 2, are compared with existing horizontally polarized omnidirectional antennas. Their performance is summarized in Table 1. The wavelength represents the center frequency of the operating band. Table 1 shows that existing horizontally polarized omnidirectional antennas struggle to simultaneously achieve large bandwidth, small size, and low profile. The single-loop broadband horizontally polarized omnidirectional antenna based on aperiodic, non-uniform slot capacitance loading proposed in Example 1 has a large bandwidth, a small lateral dimension, a simple and compact structure, and very simple feeding. Compared to similar horizontally polarized omnidirectional antennas, it has the largest bandwidth-to-area ratio. The dual-loop bandwidth horizontally polarized omnidirectional antenna based on aperiodic, non-uniform slot capacitance loading proposed in Example 2 also has a large bandwidth, a simple and compact structure, and even simpler feeding. Compared to similar horizontally polarized omnidirectional antennas, it also has a large bandwidth-to-area ratio.

[0070] Table 1 Performance Comparison of Horizontally Polarized Omnidirectional Antennas

[0071]

[0072] Reference [1] is Liu Gang, Li Yuanjun, Ye Lianghua. A broadband horizontally polarized omnidirectional antenna with low non-circularity [J]. Electronic Components and Materials, 2022, 41(8): 854-858.

[0073] The literature [2] is Wen SC, Xu YZ, Dong Y D. A horizontally polarized omnidirectional antenna for LTE applications [C]. 2021 IEEE InternationalSymposium on Antennas and Propagation and USNC-URSI Radio Science Meeting (APS / URSI), 2021: 1567-1568.

[0074] Document [3] is Cui F, Li

[0075] Reference [1] proposes a broadband horizontally polarized omnidirectional antenna based on an electric dipole array. Three arc-shaped electric dipoles are uniformly printed on the surface of a cylindrical dielectric substrate. The antenna uses a 1-to-3 power divider and broadband balun feeding to achieve good horizontal omnidirectional radiation. Three sets of directors are added to make the antenna's relative bandwidth reach 51.6%. The antenna size is only 0.48 × 0.48 mm. λ 0 2 However, due to the use of a three-dimensional structure, the cross-section is relatively high, reaching 0.24. λ 0.

[0076] Reference [2] proposes a broadband horizontally polarized omnidirectional antenna based on a Vivaldi slot antenna. Omnidirectional radiation is achieved by slotting the patch, including four Vivaldi slots and four straight slots. A 1-to-4 power divider is designed at the bottom of the dielectric substrate to feed the Vivaldi slots. The antenna has a relative bandwidth of 54.6% and a low profile of 0.007. λ 0, but the antenna's lateral dimension is relatively large, at 0.89 × 0.89. λ 0 2 .

[0077] Reference [3] proposes a broadband horizontally polarized omnidirectional antenna based on a combined loop antenna structure. The coaxial feed line excites eight circular arcs through a power divider to form horizontally polarized omnidirectional radiation. Parasitic patches are loaded outside the circular arcs to increase the antenna bandwidth. The antenna is relatively small, with a lateral dimension of 0.81 × 0.81 mm. λ 0 2 The lowest profile is 0.007. λ 0, but the antenna bandwidth is only 27.4%.

Claims

1. A loop-type broadband horizontally polarized omnidirectional antenna based on aperiodic, non-uniform slot capacitance loading, characterized in that: It includes a first dielectric substrate, a single-ring radiating patch, a first power supply port, and an impedance matching line. The single-ring radiating patch is disposed on the upper surface of the first dielectric substrate, and the first power supply port supplies power to the single-ring radiating patch through the impedance matching line. The lower surface of the first dielectric substrate is unstructured; The single-ring radiating patch is an aperiodic non-uniform slot capacitive loading structure. The aperiodic non-uniform slot capacitive loading structure is obtained by aperiodicly cutting slots along the loop direction near the first feed port on the circular transmission line, and the curvature of each cut slot is different. The cut gap is equivalent to introducing a series capacitor on the circular transmission line. By introducing the series capacitor, the current phase and current direction on the single-ring radiating patch remain unchanged, and a horizontally polarized omnidirectional radiation mode is obtained. By changing the curvature of the gap, the resonant frequency of the antenna and the impedance matching effect are adjusted, thereby increasing the bandwidth of the antenna.

2. The ring-shaped broadband horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading according to claim 1, characterized in that: The first feed port and impedance matching line are both located inside the single-ring radiating patch.

3. A ring-shaped broadband horizontally polarized omnidirectional antenna based on aperiodic non-uniform slot capacitance loading according to claim 1, characterized in that: The impedance matching between the first feed port and the single-ring radiating patch can be adjusted by adjusting the length and width of the impedance matching line.

4. A loop-type broadband horizontally polarized omnidirectional antenna based on aperiodic, non-uniform slot capacitance loading, characterized in that: It includes a second dielectric substrate, an outer ring radiating patch, an inner ring radiating patch, and a second power supply port; the outer ring radiating patch, the inner ring radiating patch, and the second power supply port are all located on the upper surface of the second dielectric substrate, the inner ring radiating patch is disposed inside the outer ring radiating patch as a parasitic ring, the second power supply port directly feeds the outer ring radiating patch and couples to feed the inner ring radiating patch; the lower surface of the second dielectric substrate has no structure; The outer ring radiating patch is an aperiodic, non-uniform slot capacitor loading structure. The aperiodic, non-uniform slot capacitor loading structure is obtained by making aperiodic cuts along the loop direction near the second feed port on the circular transmission line, with each cut having a different arc. The cuts are equivalent to introducing series capacitors on the circular transmission line. By introducing series capacitors, the current phase and current direction on the outer ring radiating patch remain unchanged, thus obtaining a horizontally polarized omnidirectional radiation mode. The arc and position of the slits cut on the inner ring radiating patch correspond to the arc and position of the slits cut on the outer ring radiating patch, so as to form horizontally polarized omnidirectional radiation while adjusting the impedance matching of the antenna. The resonant frequency and impedance matching of the antenna can be adjusted by changing the curvature of the slit, the width of the outer ring radiating patch, and the width of the inner ring radiating patch. By adjusting the radius and width of the outer and inner ring radiating patches, the resonant points of the outer and inner ring radiating patches are brought closer to each other, thereby extending the antenna bandwidth.

Images