A dual-polarized omni-directional antenna applied to indoor distribution

Abstract

The application belongs to the technical field of wireless communication, and particularly relates to a dual-polarized omnidirectional antenna applied to indoor distribution, which comprises a vertical polarization unit and a horizontal polarization unit. The vertical polarization unit comprises two vertically placed metal patches, a top-loaded metal disc and a vertical polarization unit input port. The horizontal polarization unit comprises a dielectric substrate, a metal ground and a dielectric resonator. The lower surface of the dielectric substrate is provided with a feed structure. The dielectric resonator is annular in shape and has a circular truncated cone-shaped gap in the center. The metal ground is symmetrically provided on both sides with a pair of arc-shaped metal dipoles located above the dielectric substrate. The arc-shaped metal dipole comprises two dipole arms and an open-circuit stub. The outer side of the arc-shaped metal dipole is symmetrically provided with four parasitic patches. The combination of the dielectric resonator and the arc-shaped metal dipole ensures wideband omnidirectional radiation while greatly reducing the planar size of the antenna, thereby making up for the defect of large structure size commonly existing in the existing indoor distribution antenna.

Description

Technical Field

[0001] This invention belongs to the field of wireless communication technology, specifically relating to a dual-polarized omnidirectional antenna for indoor distribution. Background Technology

[0002] Indoor communication, as one of the main communication scenarios in modern mobile communication, requires indoor distributed antenna systems to ensure its communication quality. Indoor distributed antennas can provide both source and destination signals for indoor communication, enabling signal transmission, and have broad application prospects in 2G / 3G / LTE / 5G frequency bands. Generally, each destination in an indoor scenario needs to receive a good signal, which requires indoor distributed antennas to have good omnidirectional radiation characteristics, i.e., low non-circularity across the omnidirectional plane.

[0003] Currently, when implementing dual polarization in indoor distributed antennas, it is generally accomplished by two omnidirectional radiating elements: a vertical polarization element and a horizontal polarization element. The vertical polarization element can easily achieve a wider frequency coverage, while the horizontal polarization element usually struggles to achieve a comparable operating bandwidth and has a larger planar size, making miniaturization designs rare. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a dual-polarized omnidirectional antenna for indoor distribution, thereby realizing the miniaturization of the antenna.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0006] A dual-polarized omnidirectional antenna for indoor distribution includes a vertical polarization unit and a horizontal polarization unit, with the vertical polarization unit embedded within the horizontal polarization unit. The vertical polarization unit includes two vertically placed metal patches, a top-loaded metal disk, and a vertical polarization unit input port. The horizontal polarization unit includes a dielectric substrate, a metal ground, and a dielectric resonator stacked sequentially from bottom to top. The lower surface of the dielectric substrate has a feed structure for the horizontal polarization unit. The dielectric resonator is annular in shape with a frustum-shaped notch in its center, the radius of which gradually decreases from the side furthest from the dielectric substrate to the side closest to it. A pair of arc-shaped metal elements are symmetrically arranged on both sides of the metal ground, located above the dielectric substrate. Each arc-shaped metal element includes two arms and an open-circuit stub located at the end of the arm furthest from the metal ground. Four parasitic patches are symmetrically arranged on the outer side of the arc-shaped metal elements, located above the dielectric substrate. The arms and parasitic patches are completely covered by the dielectric resonator, while the upper surface of the open-circuit stub is exposed to the outside.

[0007] As a further preferred embodiment of the present invention, the metal patch of the vertical polarization unit is composed of a trapezoid and a rectangle.

[0008] Furthermore, as a preferred embodiment of the present invention, the two arc-shaped metal oscillators are arranged in a symmetrical manner to form an equivalent current loop.

[0009] As a further preferred embodiment of the present invention, the metal ground and the dielectric substrate have overlapping central circular holes in the metal ground and the dielectric substrate, and the projections of the central circular hole in the metal ground, the central circular hole in the dielectric substrate, and the inner hole of the ring dielectric resonator on the dielectric substrate are concentric.

[0010] As a further preferred embodiment of the present invention, the metal ground is provided with two rectangular grooves symmetrically at both ends near the arc-shaped metal oscillator.

[0011] As a further preferred embodiment of the present invention, the power supply structure of the horizontal polarization unit includes an input port, a power divider, and two power supply arms; the input port is connected to the center point of the power divider; and the two ends of the power divider are respectively connected to the two power supply arms.

[0012] As a further preferred embodiment of the present invention, the metal ground, the arc-shaped metal oscillator and the parasitic patch are printed on the upper surface of the dielectric substrate.

[0013] As a further preferred embodiment of the present invention, the feeding structure of the horizontal polarization unit is printed on the lower surface of the dielectric substrate.

[0014] As a further preferred embodiment of the present invention, the feeding structure of the horizontal polarization unit excites the arc-shaped metal oscillator and the dielectric resonator through coupling.

[0015] The dual-polarized omnidirectional antenna for indoor distribution described in this invention has the following technical advantages compared with existing technologies:

[0016] The two vertically placed metal patches of this invention reduce coupling with the horizontal polarization unit and improve isolation between the two ports. The frustum-shaped notch of the ring dielectric resonator helps to extend the antenna's operating bandwidth and facilitates the embedding of the vertical polarization unit to meet the application requirements of dual polarization. The arm of the arc-shaped metal vibrator is completely covered by the dielectric resonator, and the dielectric covering the arm effectively reduces the waveguide wavelength of the arm to achieve miniaturization. The two arc-shaped metal vibrators are arranged symmetrically to form an equivalent current loop, providing good omnidirectional radiation performance. At the same time, four parasitic patches symmetrically placed on the outside of the arc-shaped metal vibrators can improve the non-circularity of the omnidirectional radiation pattern of the antenna in the azimuth plane. The combination of the dielectric resonator and the arc-shaped metal vibrator greatly reduces the planar size of the antenna while ensuring wideband omnidirectional radiation, making up for the large structural size defect that is common in existing indoor distributed antennas. Attached Figure Description

[0017] Figure 1 This invention relates to a structural perspective view of a dual-polarized omnidirectional antenna for indoor distribution;

[0018] Figure 2 This invention relates to a side view of a dual-polarized omnidirectional antenna for indoor distribution;

[0019] Figure 3 This is a top view of a horizontally polarized cell.

[0020] Figure 4 A bottom view of a horizontally polarized cell;

[0021] Figure 5 This invention relates to an S-parameter diagram of a dual-polarized omnidirectional antenna for indoor distribution;

[0022] Figure 6 The radiation pattern of the horizontally polarized unit at 0.725 GHz;

[0023] Figure 7 The radiation pattern of the horizontally polarized unit at 0.79 GHz;

[0024] Figure 8 The radiation pattern of the horizontally polarized unit at 0.92 GHz;

[0025] Figure 9 The radiation pattern of the vertically polarized unit at 0.725 GHz;

[0026] Figure 10 The radiation pattern of the vertically polarized unit at 0.79 GHz;

[0027] Figure 11The radiation pattern of the vertically polarized unit at 0.92 GHz;

[0028] In the attached diagram, 11-metal patch; 12-top-loaded metal disk; 13-vertical polarization unit input port; 2-dielectric resonator; 3-metal ground; 31-central circular hole of metal ground; 32-rectangular slot; 4-arc-shaped metal oscillator; 41-oscillator arm; 42-open circuit stub; 5-parasitic patch; 6-dielectric substrate; 61-central circular hole of dielectric substrate; 7-feeding structure of horizontal polarization unit; 71-input port; 72-power divider; 73-feeding arm. Detailed Implementation

[0029] The present invention will be further explained in detail below with reference to the accompanying drawings, so that those skilled in the art can better understand and implement the present invention. However, the following examples are only used to explain the present invention and are not intended to limit the present invention.

[0030] Figure 1 This invention relates to a structural perspective view of a dual-polarized omnidirectional antenna for indoor distribution, comprising a metal patch 11, a top-loaded metal disk 12, a vertical polarization unit input port 13, a dielectric resonator 2, a metal ground 3, a pair of arc-shaped metal elements 4, a parasitic patch 5, a dielectric substrate 6, and a feeding structure 7 for the horizontal polarization unit. The metal ground 3, the arc-shaped metal elements 4, and the parasitic patch 5 are printed on the upper surface of the dielectric substrate 6, and both arc-shaped metal elements 4 are connected to the metal ground 3; the feeding structure 7 for the horizontal polarization unit is printed on the lower surface of the dielectric substrate 6, and excites the arc-shaped metal elements 4 and the dielectric resonator 2 through coupled feeding.

[0031] like Figure 2 As shown, the metal patch 11 consists of a trapezoid and a rectangle, and the vertical polarization unit input port 13 is connected to the vertically placed metal patch 11.

[0032] like Figure 3 As shown, the dielectric resonator 2 is annular in shape with a frustum-shaped notch in the center. The radius of the frustum-shaped notch gradually decreases from the side away from the dielectric substrate 6 to the side closer to the dielectric substrate 6. The frustum-shaped notch helps to expand the operating bandwidth of the antenna and facilitates the embedding of vertical polarization units to meet the application requirements of dual polarization. Each of the arc-shaped metal elements 4 includes two elements arms 41 and two open-circuit stubs 42, with the open-circuit stubs located at the ends of the two arc-shaped elements arms 41 away from the metal ground 3. The two arc-shaped metal elements 4 are arranged symmetrically to form an equivalent current loop, which can provide good omnidirectional radiation performance. The metal ground 3 has a central circular hole 31 in the center, and two rectangular slots 32 are symmetrically distributed at both ends of the metal ground 3 near the arc-shaped metal elements 4. Parasitic patches 5 are symmetrically placed on the outside of the arc-shaped metal elements 4 to reduce the non-circularity of the antenna.

[0033] like Figure 4 As shown, the dielectric substrate 6 is circular in shape and has a central circular hole 61. The central circular hole 61 of the dielectric substrate is completely overlapped with the central circular hole 31 of the metal ground 3 printed on the upper surface of the dielectric substrate 6. The power supply structure 7 of the horizontal polarization unit is printed on the lower surface of the dielectric substrate 6 and includes an input port 71, a power divider 72 and two power supply arms 73. The input port 71 is connected to the center point of the power divider 72. The two ends of the power divider 72 are respectively connected to the two power supply arms 73.

[0034] The feeding structure 7 of the horizontally polarized unit excites the arc-shaped metal oscillator 4 and the dielectric resonator 2 through coupling. The dielectric resonator 2 partially covers the arc-shaped metal oscillator 4 to achieve miniaturization of the arc-shaped metal oscillator 4. Specifically, the oscillator arm 41 of the arc-shaped metal oscillator 4 is completely covered by the dielectric resonator 2, and the upper surface of the open-circuit stub 42 is exposed to the outside world, located between the dielectric resonator 2 and the dielectric substrate 6. The dielectric covering the oscillator arm 41 can effectively reduce the waveguide wavelength of the oscillator arm 41 to achieve miniaturization of the oscillator arm 41. The present invention relates to a dual-polarized omnidirectional antenna for indoor distribution, which uses the arc-shaped metal oscillator 4 and the dielectric resonator 2 to achieve broadband omnidirectional radiation performance. Its planar dimensions are only 0.36λlow × 0.36λlow (λlow is the wavelength in free space at the lowest operating frequency of the antenna), showing a significant advantage in miniaturization.

[0035] Figure 5 This invention illustrates the S-parameter plot of a dual-polarized omnidirectional antenna for indoor distribution, demonstrating that the relative bandwidth of the horizontal polarization element (|S_parameter|) is... 11 |<-10dB) is 30% (0.72GHz~0.96GHz), the relative bandwidth of the vertical polarization unit (|S 22 The overlap bandwidth between horizontal and vertical polarization units is 81.25% (0.65GHz to 1.30GHz), the overlap bandwidth between horizontal and vertical polarization units is 30% (0.72GHz to 0.96GHz), and the isolation between input port 13 and input port 71 of vertical polarization unit is greater than 40dB.

[0036] Figure 6 , Figure 7 and Figure 8 The radiation patterns of the horizontally polarized unit at 0.725 GHz, 0.79 GHz, and 0.92 GHz are shown. The results indicate that the design exhibits good pattern consistency within the operating frequency band, with the main polarization pattern non-circularity of the horizontal plane of the unit being less than 1.8 dB and the cross-polarization level within the band being below -25 dB; the horizontal polarization also demonstrates good omnidirectional radiation performance.

[0037] Figure 9, Figure 10 and Figure 11 The radiation patterns of the vertical polarization unit at 0.725 GHz, 0.79 GHz, and 0.92 GHz are shown. The results indicate that the design exhibits good pattern consistency within the operating frequency band, with the main polarization pattern non-circularity in the horizontal plane of the vertical polarization unit being less than 0.5 dB, and the cross-polarization level within the band being below -30 dB. The omnidirectional radiation performance of the vertical polarization is also good.

[0038] The two vertically placed metal patches of this invention reduce coupling with the horizontal polarization unit and improve isolation between the two ports. The frustum-shaped notch of the ring dielectric resonator helps to extend the antenna's operating bandwidth and facilitates the embedding of the vertical polarization unit to meet the application requirements of dual polarization. The arm of the arc-shaped metal oscillator is completely covered by the dielectric resonator, and the dielectric covering the arm effectively reduces the waveguide wavelength of the arm to achieve miniaturization. The two arc-shaped metal oscillators are arranged "face-to-face" to form an equivalent current loop, which provides good omnidirectional radiation performance. At the same time, four parasitic patches symmetrically placed on the outside of the arc-shaped metal oscillators can reduce the antenna's non-circularity. This invention enables the isolation between the two ports of an indoor distributed dual-polarized omnidirectional antenna to be greater than 40dB, and the planar size to be reduced to 0.36λlow×0.36λlow (λlow is the lowest operating frequency of the antenna, the wavelength in free space). The non-circularity of the horizontal polarization element is less than 1.8dB, and the non-circularity of the vertical polarization element is less than 0.5dB. This largely overcomes the shortcomings of existing antennas of the same type, such as large structural size, poor non-circularity, and low isolation.

[0039] The specific implementation schemes described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific implementation schemes of the present invention and are not intended to limit the scope of the present invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention should fall within the scope of protection of the present invention.

Claims

1. A dual-polarized omni-directional antenna applied to indoor distribution, comprising a vertical polarization unit and a horizontal polarization unit, the vertical polarization unit being embedded in the horizontal polarization unit; the vertical polarization unit comprising two vertically placed metal patches (11), a top-loaded metal disc (12) and a vertical polarization unit input port (13); the horizontal polarization unit comprising a dielectric substrate (6), a metal ground (3) and a dielectric resonator (2) stacked in order from bottom to top, the lower surface of the dielectric substrate (6) being provided with a horizontal polarization unit feed structure (7), characterized in that, The shape of the dielectric resonator (2) is annular and has a circular truncated cone-shaped notch in the center, the radius of the circular truncated cone-shaped notch gradually decreases from the side far away from the dielectric substrate (6) to the side close to the dielectric substrate (6); the metal ground (3) is symmetrically provided with a pair of arc-shaped metal oscillators (4) above the dielectric substrate (6), the arc-shaped metal oscillator (4) includes two oscillator arms (41) and an open-circuit stub (42) at the end of the oscillator arm (41) away from the metal ground (3), the outer side of the arc-shaped metal oscillator (4) is symmetrically provided with four parasitic patches (5) above the dielectric substrate (6), the oscillator arm (41) and the parasitic patch (5) are completely covered by the dielectric resonator (2), and the upper surface of the open-circuit stub (42) is exposed to the outside; the two arc-shaped metal oscillators (4) are arranged in a symmetrical form, forming an equivalent current loop; the metal ground (3) and the dielectric substrate (6) have a coincident metal ground central circular hole (31) and a dielectric substrate central circular hole (61), and the metal ground central circular hole (31), the dielectric substrate central circular hole (61) and the inner hole of the annular dielectric resonator (2) are concentric on the dielectric substrate (6).

2. The dual-polarized omni-directional antenna for indoor distribution according to claim 1, characterized in that, The metal patch (11) is composed of a trapezoid and a rectangle.

3. The dual-polarized omni-directional antenna for indoor distribution according to claim 1, characterized in that, The metal ground (3) is symmetrically provided with two rectangular grooves (32) near the two ends of the arc-shaped metal oscillator (4).

4. The dual-polarized omni-directional antenna for indoor distribution according to claim 1, characterized in that, The feed structure (7) of the horizontal polarization unit includes an input port (71), a power divider (72) and two feed arms (73); the input port (71) is connected with the center point of the power divider (72); the two ends of the power divider (72) are respectively connected with the two feed arms (73).

5. The dual-polarized omni-directional antenna for indoor distribution according to claim 1, characterized in that, The metal ground (3), the arc-shaped metal oscillator (4) and the parasitic patch (5) are printed on the upper surface of the dielectric substrate (6).

6. The dual-polarized omni-directional antenna for indoor distribution according to claim 1, characterized in that, The feed structure (7) of the horizontal polarization unit is printed on the lower surface of the dielectric substrate (6).

7. The dual-polarized omni-directional antenna for indoor distribution according to claim 1, characterized in that, The feed structure (7) of the horizontal polarization unit excites the arc-shaped metal oscillator (4) and the dielectric resonator (2) in a coupling mode.

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