Ultra-wideband low-profile vertically polarized omnidirectional antenna

Abstract

The present application provides an ultra-wideband low-profile vertically polarized omnidirectional antenna, comprising a metal floor, a radiation arm, and a metal disc. The radiation arm comprises corrugated radiation arms and long straight radiation arms which are alternately arranged in a radial shape; the top of the radiation arm is fixedly connected to the metal disc; the outer ends of the corrugated radiation arms are connected to the metal floor; and the parts inside the outer ends of the corrugated radiation arms are suspended above the metal floor. According to the antenna of the present invention, the corrugated radiation arms are combined with the metal disc at the top, thereby reducing the profile height of the antenna; the long straight radiation arms can generate resonance points at high-frequency points, and the resonance points are combined with resonance points generated by the corrugated radiation arms, thereby expanding the bandwidth of the antenna; six arc-shaped grooves are etched in the metal floor, so that the radiation performance at the high-frequency points can be improved, thereby ensuring the stability of the pattern of the antenna in the whole working frequency band; and the outermost end of the metal floor is bent upwards and inwards, thereby reducing the plane size of the antenna while achieving a low profile and not affecting the performance of the antenna.

Description

Ultra-wideband low-profile vertically polarized omnidirectional antenna

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on August 7, 2023, with application number 202310982592.0 and application name “An ultra-wideband low-profile vertically polarized omnidirectional antenna for indoor distributed systems”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of antenna technology, and in particular to an ultra-wideband low-profile vertically polarized omnidirectional antenna. Background Art

[0003] In current mobile communications, the demand for indoor base stations is increasing, and indoor communications have become a primary communication scenario in daily life. Omnidirectional antennas that achieve 360° signal coverage are the preferred choice for indoor base stations. With the large-scale commercialization of 5G, the use of 5G antennas has become widespread. Meanwhile, the 2G / 3G / LTE frequency bands continue to play an important role in the evolution of communications technology. Therefore, developing antennas that simultaneously cover the 2G / 3G / LTE / 5G frequency bands holds great promise. The 1.7-2.7 GHz frequency band is a key application for 4G LTE (long-term evolution) networks and has attracted considerable attention in base station antenna design. Furthermore, N78 (3.3-3.8 GHz) and N79 (4.8-5 GHz) are key frequency bands for 5G communications deployment and testing. Since indoor distributed omnidirectional antennas are mounted on the ceiling, their low profile saves space and enhances aesthetics. Therefore, there is an urgent need for low-profile indoor distributed antennas that can simultaneously cover all three frequency bands.

[0004] Traditional indoor distributed omnidirectional antennas are primarily categorized as single-polarization omnidirectional and dual-polarization omnidirectional. Single-polarization omnidirectional antennas typically utilize vertical polarization. This is because vertically polarized waves propagate more easily over undulating terrain in terrestrial mobile communications, significantly reducing energy attenuation. Currently, vertically polarized antennas are often implemented using monopoles or conical antennas, which are large in size and expensive to manufacture. Furthermore, ultra-wideband omnidirectional antennas often suffer from pattern degradation at high frequencies.

[0005] After searching, it was found that Chinese invention patent CN109687132A discloses a low-profile vertically polarized ultra-wideband omnidirectional antenna, which includes: several triangular metal pieces, short-circuit metal posts, circular metal pieces, rectangular ground plates and coaxial feed parts. The cross-sectional height of the vertically polarized omnidirectional antenna is 0.128λ. low (λ lowis the wavelength in free space at the lowest operating frequency of the antenna). At high frequencies, the horizontal plane pattern deteriorates severely, with a non-circularity greater than 5dB.

[0006] Summary of the Invention

[0007] In view of this, the present application provides an ultra-wideband low-profile vertically polarized omnidirectional antenna, which effectively solves the problems of large cross-sectional size and deteriorated radiation pattern at high frequency points of existing ultra-wideband vertically polarized omnidirectional antennas.

[0008] In the first aspect, the present application discloses an ultra-wideband, low-profile, vertically polarized omnidirectional antenna, comprising a metal disc, a radiating arm, and a metal floor. An SMA head is inserted upward from the central hole of the metal floor, the inner conductor of the SMA head is connected to the inner end of the radiating arm, and the outer conductor of the SMA head is connected to the metal floor. The metal disc is supported overhead above the metal floor by the radiating arm, and the radiating arm comprises a long straight radiating arm and a wavy radiating arm arranged alternately in a radial pattern; the outer end of the long straight radiating arm is fixedly connected to the metal disc; the top of the wavy radiating arm is fixedly connected to the metal disc, the bottom of the outer end of the wavy radiating arm is connected to the metal floor, and the part within the outer end of the wavy radiating arm is suspended above the metal floor.

[0009] In some possible implementations, the metal disc and the metal floor are circular in shape, and the centers of the two circles are located on the same vertical line.

[0010] In some possible implementations, the wavy radiating arm is formed by a rectangular metal sheet that is bent several times. The wavy radiating arm is combined with a metal disk to reduce the cross-sectional height of the antenna; the long straight radiating arm generates a resonance point at a high frequency point, which is combined with the resonance point generated by the wavy radiating arm to expand the bandwidth of the antenna.

[0011] In some possible implementations, the metal floor is provided with arc-shaped grooves located one-to-one on the outside of the radiating arm, and the center of the arc-shaped groove and the center of the metal floor are located on the same vertical line, which is used to improve the radiation performance at high frequency points to ensure the stability of the antenna's radiation pattern within the entire working frequency band.

[0012] In some possible implementations, the outer end of the metal floor is bent upward and inward to reduce the planar size of the antenna while achieving a low profile and not affecting antenna performance.

[0013] In some possible implementations, the number of the long straight radiating arms and the number of the wavy radiating arms are both 3, and the angle between adjacent long straight radiating arms and wavy radiating arms is 60°.

[0014] In some possible implementations, a feeding port is provided at the central hole of the metal floor, and the SMA head is fixed through the feeding port.

[0015] In some possible implementations, the number of bends and the bending angle of the zigzag radiating arm are adjusted according to impedance matching of the antenna.

[0016] In some possible implementations, the metal disc, the radiation arm, and the metal floor are made of copper and are formed into an integral structure through 3D printing technology.

[0017] In a second aspect, the present application provides an antenna, comprising any of the above-mentioned ultra-wideband low-profile vertically polarized omnidirectional antennas.

[0018] Combining the aforementioned technical solutions, the undulating radiating arm and the top metal disc reduce the antenna height to meet low-profile application requirements, with a profile height of only 5.4% of the vacuum wavelength at the lowest operating frequency. The long straight radiating arm generates resonance points at high frequencies, which, combined with the resonance points generated by the undulating radiating arm, expands the antenna's bandwidth. The radiating arm also serves as a support for the top metal disc. Six arc-shaped grooves etched into the metal floor mitigate the degradation of ultra-wideband antenna radiation performance at high frequencies, ensuring the stability of the antenna's radiation pattern across the entire operating frequency band. The outermost end of the metal floor curves upward and inward, reducing the antenna's planar dimensions while achieving a low profile without compromising performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG1 is a structural perspective view of an ultra-wideband low-profile vertically polarized omnidirectional antenna according to the present invention;

[0020] FIG2 is a front view of an ultra-wideband low-profile vertically polarized omnidirectional antenna according to the present invention;

[0021] FIG3 is a top view of a metal floor of an ultra-wideband low-profile vertically polarized omnidirectional antenna according to the present invention;

[0022] FIG4 is a reflection coefficient and gain curve diagram of an ultra-wideband low-profile vertically polarized omnidirectional antenna according to the present invention;

[0023] FIG5 is a directional diagram of an ultra-wideband low-profile vertically polarized omnidirectional antenna according to the present invention at a frequency of 2.2 GHz;

[0024] FIG6 is a directional diagram of an ultra-wideband low-profile vertically polarized omnidirectional antenna according to the present invention at a frequency of 3.5 GHz;

[0025] FIG7 is a directional diagram of an ultra-wideband low-profile vertically polarized omnidirectional antenna according to the present invention at a frequency of 4.8 GHz.

[0026] In the accompanying drawings, 1 is a metal disc; 2 is a radiation arm; 3 is a metal floor; 21 is a wavy metal arm; 22 is a long straight metal arm; 31 is an arc-shaped groove; and 32 is a central hole. DETAILED DESCRIPTION

[0027] In order to more clearly understand the above-mentioned objectives, features and advantages of the present application, the present application is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features therein can be combined with each other in the absence of conflict.

[0028] In the following description, many specific details are set forth to facilitate a full understanding of the present application. The described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0030] It should be further noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0031] In this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural.

[0032] As shown in Figures 1 to 3, the present invention relates to a structural perspective view of an ultra-wideband, low-profile, vertically polarized omnidirectional antenna, comprising a metal disc 1, a radiating arm 2, and a metal floor 3. An SMA head is inserted upward from the central hole 32 of the metal floor 3. The inner conductor of the SMA head is connected to the inner end of the radiating arm 2, and the outer conductor of the SMA head is connected to the metal floor 3. The metal disc 1 is supported overhead above the metal floor 3 by the radiating arm 2. The metal disc 1 and the metal floor 3 are circular in shape, with their centers located on the same vertical line. A feed port is provided at the central hole 32 of the metal floor 3, and the SMA head is fixed via the feed port. The metal disc 1, radiating arm 2, and the metal floor 3 are made of copper and formed into an integral structure using 3D printing technology.

[0033] In this embodiment, the radiation arm 2 includes three long straight radiation arms 22 and three wavy radiation arms 21. The long straight radiation arms 22 and the wavy radiation arms 21 are arranged alternately in a radial pattern, and the angle between adjacent long straight radiation arms 22 and wavy radiation arms 21 is 60°. The outer end of the long straight radiation arm 22 is upturned and fixedly connected to the metal disc 1, and the inner end of the long straight radiation arm 22 is connected to the inner conductor of the SMA head. The long straight radiation arm 22 is used to generate a resonance point at a high frequency point to expand the antenna bandwidth. The wavy radiation arm 21 is formed by a rectangular metal sheet that is bent several times. The number of bends and the bending angle can be adjusted according to the antenna performance (antenna impedance matching). The top of the wavy radiating arm 21 is fixedly connected to the metal disc 1, the bottom of the outer end of the wavy radiating arm 21 is connected to the metal floor 3, the inner end of the wavy radiating arm 21 is connected to the inner conductor of the SMA head, and the part inside the outer end of the wavy radiating arm 21 is suspended above the metal floor 3, that is, a gap is formed between the bottom of the part inside the outer end of the wavy radiating arm 21 and the metal floor 3.

[0034] As shown in Figure 1, the metal floor 3 is provided with six arcuate slots 31, one for each of the outer sides of the radiating arms 2, with the center of each slot 31 and the center of the metal floor 3 lying on the same vertical line. These six arcuate slots 31 effectively improve the deterioration of the ultra-wideband antenna's radiation performance at high frequencies, thereby ensuring the stability of the antenna's radiation pattern throughout the entire operating frequency band. The outermost end of the metal floor 3 bends upward and inward to reduce the antenna's planar dimensions to 0.82λ. low (λ low The wavelength in free space at the antenna's lowest operating frequency).

[0035] The metal disc 1 extends the current path on the radiating arm 2. The three wavy radiating arms 21 combined with the metal disc 1 help reduce the antenna's profile height. The three long straight radiating arms 22 are used to generate high-frequency resonance points to expand the antenna's bandwidth. The antenna's cross-sectional size is only 0.054λ. low, which to a large extent makes up for the common defect of large cross-sectional size in existing similar antennas.

[0036] The embodiment of the present invention optimizes the dimensions of various parts of the antenna. Specific antenna parameters are shown in the table below:

[0037] In the table, r1 is the radius of the metal disk 1, r2 is the radius of the metal floor 3, r3 is the inward bend width of the metal floor 3, r4 is the distance from the center of the arcuate slot 31, t is the thickness of the metal disk 1 and the metal floor 3, l1 is the projected length of the undulating radiating arm 21, l2 is the projected length of the long straight radiating arm 22, w1 is the width of the undulating radiating arm 21, w2 is the width of the long straight radiating arm 22, w3 is the width of the arcuate slot 31, h1 is the distance between the metal disk 1 and the metal floor 3, h2 is the height of the upward bend of the metal floor 3, h3 is the distance between the inner bottom of the undulating radiating arm 21 and the metal floor 3, and α is the angle of the arcuate slot 31. Furthermore, the thickness of the undulating radiating arm 21 is 1.91 mm, and the thickness of the long straight radiating arm 22 is 1.78 mm.

[0038] FIG4 shows the reflection coefficient and gain curve of an ultra-wideband low-profile vertically polarized omnidirectional antenna involved in the present invention. The results show that the relative bandwidth of the design is 105.22% (1.68 to 5.41 GHz), and the gain within the operating frequency band is between 3.8 dBi and 8 dBi.

[0039] Figures 5, 6, and 7 show the antenna's radiation patterns at three different frequencies. The results demonstrate that the design maintains good directional consistency across the operating frequency band, particularly at high frequencies, where the pattern exhibits excellent omnidirectionality, achieving excellent omnidirectional radiation performance across the entire operating frequency band.

[0040] In addition, the present invention also claims protection for an antenna, including the ultra-wideband low-profile vertically polarized omnidirectional antenna of this embodiment.

[0041] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An ultra-wideband low-profile vertically polarized omnidirectional antenna, comprising a metal disc (1), a radiating arm (2) and a metal floor (3), wherein an SMA head is inserted upward from a central hole (32) of the metal floor (3), an inner conductor of the SMA head is connected to an inner end of the radiating arm (2), and an outer conductor of the SMA head is connected to the metal floor (3), and the metal disc (1) is supported overhead above the metal floor (3) by the radiating arm (2), characterized in that: The radiation arm (2) comprises a long straight radiation arm (22) and a wavy radiation arm (21) which are alternately arranged in a radial shape; the outer end of the long straight radiation arm (22) is fixedly connected to the metal disc (1); the top of the wavy radiation arm (21) is fixedly connected to the metal disc (1), the bottom of the outer end of the wavy radiation arm (21) is connected to the metal floor (3), and the portion inside the outer end of the wavy radiation arm (21) is suspended above the metal floor (3).

2. The ultra-wideband low-profile vertically polarized omnidirectional antenna according to claim 1, characterized in that: The metal disc (1) and the metal floor (3) are circular in shape, and the centers of the two circles are located on the same vertical line.

3. The ultra-wideband low-profile vertically polarized omnidirectional antenna according to claim 1, characterized in that: The wavy radiating arm (21) is formed by bending a rectangular metal sheet several times, and the wavy radiating arm (21) is combined with the metal disc (1) to reduce the cross-sectional height of the antenna; the long straight radiating arm (22) generates a resonance point at a high frequency point, which is combined with the resonance point generated by the wavy radiating arm to expand the bandwidth of the antenna.

4. The ultra-wideband low-profile vertically polarized omnidirectional antenna according to claim 1, characterized in that: The metal floor (3) is provided with arc grooves (31) located one-to-one on the outside of the radiation arm (2), and the center of the arc groove (31) and the center of the metal floor (3) are located on the same vertical line, which are used to improve the radiation performance at high frequency points to ensure the stability of the antenna's directional pattern in the entire working frequency band.

5. The ultra-wideband low-profile vertically polarized omnidirectional antenna according to claim 1, characterized in that: The outer end of the metal floor (3) is bent upward and inward, so as to reduce the planar size of the antenna while achieving a low profile and not affecting the antenna performance.

6. The ultra-wideband low-profile vertically polarized omnidirectional antenna according to claim 5, characterized in that: The number of the long straight radiation arms (22) and the number of the wavy radiation arms (21) are both three, and the angle between adjacent long straight radiation arms (22) and wavy radiation arms (21) is 60°.

7. The ultra-wideband low-profile vertically polarized omnidirectional antenna according to claim 1, characterized in that: A feeding port is provided at the central hole (32) of the metal floor (3), and the SMA head is fixed via the feeding port.

8. The ultra-wideband low-profile vertically polarized omnidirectional antenna according to claim 1, characterized in that: The number of bends and the bend angle of the folded radiation arm (21) are adjusted according to the impedance matching of the antenna.

9. The ultra-wideband low-profile vertically polarized omnidirectional antenna according to claim 1, characterized in that: The metal disc (1), the radiation arm (2) and the metal floor (3) are made of copper and form an integral structure through 3D printing technology.

10. An antenna, characterized in that: It comprises an ultra-wideband low-profile vertically polarized omnidirectional antenna as described in any one of claims 1 to 9.

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