WO2015109996A1

WO2015109996A1 - Horizontally polarized omni-directional antenna

Info

Publication number: WO2015109996A1
Application number: PCT/CN2015/071142
Authority: WO
Inventors: Yihong Qi; Wei Yu
Original assignee: Supeq(Nanjing) Communication Technologies Co., Ltd.
Priority date: 2014-01-21
Filing date: 2015-01-20
Publication date: 2015-07-30
Also published as: CN103811861A; CN103811861B

Abstract

A horizontally polarized omni-directional antenna (20) includes a dielectric plate (710); a feed network (720) disposed above the dielectric plate (710) and including a plurality of feeder lines (721); a ground plate (730) disposed below the dielectric plate (710); and a plurality of printed dipoles (740) disposed below the dielectric plate (710), each printed dipole (740) being connected with the ground plate (730) and defining a gap (743) therein, the plurality of the feeder lines (721) are coupled in one-to-one correspondence with the plurality of gaps (743), and the plurality of the feeder lines (721) are short-circuited in one-to-one correspondence with the plurality of the printed dipoles (740).

Description

HORIZONTALLY POLARIZED OMNI-DIRECTIONAL ANTENNA

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority and benefits of Chinese Patent Application No.201410027024.6, filed with State Intellectual Property Office on January 21, 2014, the entire contents of which are incorporated herein by reference.

FIELD

Embodiments of the present disclosure generally relate to a horizontally polarized omni-directional antenna.

BACKGROUND

A horizontally polarized omni-directional antenna in the related art has disadvantages of poor assembling consistency, instability and lower polarization isolation between the vertically and horizontal polarized omni-directional antennas.

SUMMARY

Embodiments of the present invention seek to solve at least one of the problems existing in the related art to at least some extent.

Embodiments of the present invention provide a horizontally polarized omni-directional antenna includes a dielectric plate； a feed network disposed above the dielectric plate and including a plurality of feeder lines； a ground plate disposed below the dielectric plate； a plurality of printed dipoles disposed below the dielectric plate, each printed dipole being connected with the ground plate and defining a gap therein, wherein the plurality of the feeder lines are coupled in one-to-one correspondence with the plurality of gaps, and the plurality of the feeder lines are short-circuited in one-to-one correspondence with the plurality of the printed dipoles.

With the plurality of the feeder lines being coupled in one-to-one correspondence with the plurality of the gaps and short-circuited in one-to-one correspondence with the plurality of the printed dipoles, when the coaxial cable is introduced into the horizontally polarized omni-directional antenna, an electric current in the external conductor of the coaxial cable is suppressed efficiently, and consequently the polarization isolation between the vertically and horizontally polarized omni-directional antennas can be dramatically improved. For example, the polarization isolation between the vertically and horizontally polarized omni-directional antennas can be increased to 40dB from 25dB. Moreover, the horizontally polarized omni-directional antenna according to embodiments of the present invention has a better assembling consistency and a high stability.

Thus, the horizontally polarized omni-directional antenna according to embodiments of the present invention has a better assembling consistency, a high stability and a high polarization isolation between the vertically and horizontally polarized omni-directional antennas.

In some embodiments, the feed network further comprises a central connecting element, each feeder line has one end connected with the central connecting element and is extended in a direction away from the central connecting element. Thus, the feed network has a reasonable structure and a manufacturing difficulty of the feed network is reduced.

In some embodiments, each printed dipole comprises a left arm and a right arm, each of the left and right arms is connected with the ground plate, the gap is formed between the left and right arms, and the feeder line is short-circuited with one of the left and right arms. Thus, the printed dipole has a reasonable structure.

In some embodiments, terminals of the plurality of the feeder lines are short-circuited in one-to-one correspondence with the plurality of the printed dipoles. Thus, when the coaxial cable is introduced into the horizontally polarized omni-directional antenna, an electric current in the external conductor of the coaxial cable is suppressed efficiently, and consequently the polarization isolation between the vertically and horizontally polarized omni-directional antennas can be further improved.

In some embodiments, a short point of the feeder line and the printed dipole is adjacent to the gap. Thus, when the coaxial cable is introduced into the horizontally polarized omni-directional antenna, an electric current in the external conductor of the coaxial cable is suppressed efficiently, and consequently the polarization isolation between the vertically and horizontally polarized omni-directional antennas can be further improved.

In some embodiments, at least three feeder lines are provided, and at least three printed dipoles are provided.

In some embodiments, the horizontally polarized omni-directional antenna further includes a metal element disposed on a lower surface of the ground plate. With the metal element disposed on the lower surface of the ground plate, the out-of-roundness of the horizontally polarized omni-directional antenna is improved and an effect of the horizontally polarized omni-directional antenna on a standing wave ratio of high frequency band of the vertically polarized omni-directional antenna is reduced.

In some embodiments, the metal element is configured to have a triangular shape and extended in a vertical direction. Thus, the out-of-roundness of the horizontally polarized omni-directional antenna is further improved and an effect of the horizontally polarized omni-directional antenna on a standing wave ratio of high frequency band of the vertically polarized omni-directional antenna is further reduced.

In some embodiments, the horizontally polarized omni-directional antenna further includes a plurality of coupling branches, each coupling branch has a first end connected with the ground plate and a second end extended in a direction away from the ground plate, each coupling branch is disposed between two adjacent printed dipoles, and each printed dipole is disposed between two adjacent coupling branches. With the plurality of coupling branches, isolations and pattern out-of-roundness of the horizontally polarized omni-directional antenna and the 4G dual polarized omni-directional ceiling antenna can be adjustable.

Additional aspects and advantages of embodiments of present disclosure will be given in part in the following descriptions, become apparent in part from the following descriptions, or be learned from the practice of the embodiments of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and advantages of embodiments of the present invention will become apparent and more readily appreciated from the following descriptions made with reference the accompanying drawings, in which:

Fig. 1 is a perspective view of a 4G dual polarized omni-directional ceiling antenna according to an embodiment of the present invention；

Fig. 2 is a perspective view of a 4G dual polarized omni-directional ceiling antenna according to an embodiment of the present invention；

Fig. 3 is a perspective view of a 4G dual polarized omni-directional ceiling antenna according to an embodiment of the present invention；

Fig. 4 is a perspective view of a 4G dual polarized omni-directional ceiling antenna according to an embodiment of the present invention；

Fig. 5 is a perspective view of a vertically polarized omni-directional antenna according to an embodiment of the present invention；

Fig. 6 is a perspective view of a horizontally polarized omni-directional antenna according to an embodiment of the present invention；

Fig. 7 is a perspective view of a horizontally polarized omni-directional antenna according to an embodiment of the present invention；

Fig. 8 is a perspective view of a support of a 4G dual polarized omni-directional ceiling antenna according to an embodiment of the present invention.

DETAILED DESCRIPTION

Reference will be made in detail to embodiments of the present invention. The same or similar elements and the elements having same or similar functions are denoted by like reference numerals throughout the descriptions. The embodiments described herein with reference to drawings are explanatory, illustrative, and used to generally understand the present invention. The embodiments shall not be construed to limit the present invention.

In the specification, unless specified or limited otherwise, relative terms such as “central” , “longitudinal” , “lateral” , “front” , “rear” , “right” , “left” , “inner” , “outer” , “lower” , “upper” , “horizontal” , “vertical” , “above” , “below” , “up” , “top” , “bottom” , “inner” , “outer” , “clockwise” , “anticlockwise” as well as derivative thereof (e.g. , “horizontally” , “downwardly” , “upwardly” , etc. ) should be construed to refer to the orientation as then described or as shown in the drawings under discussion. These relative terms are for convenience of description and do not require that the present invention be constructed or operated in a particular orientation. In addition, terms such as “first” and “second” are used herein for purposes of description and are not intended to indicate or imply relative importance or significance.

In the description of the present invention, unless specified or limited otherwise, it should be noted that, terms “mounted, ” “connected” “coupled” and “fastened” may be understood broadly, such as permanent connection or detachable connection, electronic connection or mechanical connection, direct connection or indirect connection via intermediary, inner communication or interreaction between two elements. These having ordinary skills in the art should understand the specific meanings in the present invention according to specific situations.

A 4G dual polarized omni-directional ceiling antenna 1 according to embodiments of the present invention will be described with reference to Figs. 1-8. The 4G dual polarized omni-directional ceiling antenna 1 according to embodiments of the present invention includes a vertically polarized omni-directional antenna 10 and a horizontally polarized omni-directional antenna 20.

As shown in Fig. 1 to Fig. 5, the vertically polarized omni-directional antenna 10 according to embodiments of the present invention includes a base plate 100, a monopole 200, a first feeder 300, a plurality of connecting elements 400 and a coaxial cable 600.

The monopole 200 includes a central portion 210 disposed on the base plate 100 and a plurality of radiating portions 220. Each of the radiating portions 210 has an inner end connected with the central portion 210 and is extended in a direction away from the central portion 210. In other words, the plurality of radiating portions 220 are arranged radially with respect to a central axis of the central portion 210. The inner ends of the radiating portions 220 are spaced apart from one another in a circumferential direction, so as to form an accommodation space 230. The first feeder 300 is connected with the base plate 100 and the central portion 210.

The plurality of connecting elements 400 are connected in one-to-one correspondence with the plurality of the radiating portions 220, and each connecting element 400 is connected with the base plate 100. In other words, a number of the connecting elements 400 is equal to that of the radiating portions 220, and each connecting element 400 is connected with one corresponding radiating portion 220. The coaxial cable 600 has a first section 610 positioned in the accommodation space 230 and a second section.

As shown in Fig. 1 to Fig. 4, Fig. 6 and Fig. 7, the horizontally polarized omni-directional antenna 20 according to embodiments of the present invention includes a dielectric plate 710, a feed network 720, a ground plate 730 and a plurality of printed dipoles 740.

The feed network 720 is disposed above the dielectric plate 710 and includes a plurality of feeder lines 721. The ground plate 730 is disposed below the dielectric plate 710. The plurality of printed dipoles 740 are disposed below the dielectric plate 710, and each of the printed dipoles 740 is connected with the ground plate 730 and defines a gap 743 therein. The plurality of the feeder lines 721 are coupled in one-to-one correspondence with the plurality of gaps 743, and the plurality of the feeder lines 721 are short-circuited in one-to-one correspondence with the plurality of the printed dipoles 740. In other words, numbers of the feeder lines 721, printed dipoles 740 and the gaps 743 are identical, and each of the feeder lines 721 is coupled to one corresponding gap 743 and is short-circuited with one corresponding printed dipole 740.

The coaxial cable 600 includes an external conductor connected with the ground plate 730 and an internal conductor disposed within the external conductor and penetrated through the dielectric plate 710 to connect with the feed network 720.

Since a vertically polarized omni-directional antenna in the related art is generally configured as a discone antenna, i.e. an overall shape of the vertically polarized omni-directional antenna is conical. Thus, the vertically polarized omni-directional antenna in the related art is manufactured by a stamping process for metal stretch forming, which has disadvantages of complex mould and high manufacturing cost.

With the radial arrangement of the plurality of radiating portions 220 with respect to the central axis of the central portion 210, the vertically polarized omni-directional antenna 10 according to embodiments of the present invention can form a pattern of omni-directional radiation and it is not necessary for the vertically polarized omni-directional antenna to be processed into the conical shape. Thus, the manufacturing cost and difficulty of the vertically polarized omni-directional antenna 10 can be dramatically reduced.

Far more importantly, with the accommodation space 230 formed by the inner ends of the radiating portions 220 spaced apart from one another, the first section 610 of the coaxial cable 600 can be placed in the accommodation space 230, i.e. the vertically polarized omni-directional antenna 10 may have a symmetrical structure, so that an influence of the electricity of the shielding layer of the coaxial cable 600 on the out-of-roundness and the cross polarization of the vertically polarized omni-directional antenna 10 can be effectively reduced. For example, the out-of-roundness of the vertically polarized omni-directional antenna 10 can be less than 3.5dB, and the cross polarization of the vertically polarized omni-directional antenna 10 can be more than 10dB. Moreover, the coupling connection between the vertically and horizontally polarized omni-

directional antennas

10, 20 can be decreased as well, such that an assembling consistency of the vertically polarized omni-directional antenna 10 is improved.

Thus, the vertically polarized omni-directional antenna 10 according to embodiments of the present invention has advantages of a smaller out-of-roundness, a larger cross polarization, an omni-directional radiation, lower manufacturing cost and difficulty and better assembling consistency.

In the horizontally polarized omni-directional antenna 20 according to embodiments of the present invention, the feed network 720, the ground plate 730 and the plurality of printed dipoles 740 may constitute a microstrip power divider. With the plurality of the feeder lines 721 coupled in one-to-one correspondence with the plurality of the gaps 743 and short-circuited in one-to-one correspondence with the plurality of the printed dipoles 740, when the coaxial cable 600 is introduced into the horizontally polarized omni-directional antenna 20, an electric current in the external conductor of the coaxial cable 600 is suppressed efficiently, and consequently the polarization isolation between the vertically and horizontally polarized omni-

directional antennas

10, 20 can be dramatically improved. For example, the polarization isolation between the vertically and horizontally polarized omni-

directional antennas

10, 20 can be increased to 40dB from 25dB. Moreover, the horizontally polarized omni-directional antenna 20 according to embodiments of the present invention has a better assembling consistency and a high stability.

Thus, the horizontally polarized omni-directional antenna 20 according to embodiments of the present invention has a better assembling consistency, a high stability and a high polarization isolation between the vertically and horizontally polarized omni-

directional antennas

10, 20.

By disposing the vertically and horizontally polarized omni-

directional antennas

10, 20, the 4G dual polarized omni-directional ceiling antenna 1 according to embodiments of the present invention has all of advantages of the vertically and horizontally polarized omni-

directional antennas

10, 20 described above.

Therefore, the 4G dual polarized omni-directional ceiling antenna 1 according to embodiments of the present invention may be used widely in a variety of fields, such as an indoor distribution system of 4G mobile communication. In this 4G mobile communication, in order to achieve a higher communication rate, a MIMO technique may be selected, such that the vertically and horizontally polarized omni-

directional antennas

10, 20 according to embodiments of the present invention may be used as two transmission channels of the MIMO technique respectively.

In some embodiments, the inner end of each radiating element 220 and a central axis of the central portion 210 are spaced apart from each other. Thus, the vertically polarized omni-directional antenna 10 may have a reasonable structure.

Preferably, the inner end of each radiating element 220 and the central axis of the central portion 210 are spaced by a predetermined distance in a radial direction of the central portion 210. In other words, the inner ends of the plurality of the radiating elements 220 are disposed at the same circumference, and the center of the circumference is located in the central axis of the central portion 210. Thus, the vertically polarized omni-directional antenna 10 may have a reasonable structure.

As shown in Fig. 1 to Fig. 5, each of the radiating portions 220 is configured to have a plate-like shape (i.e. each of the radiating portions 220 is configured as a sheet) and oriented in a vertical direction. Thus, the vertically polarized omni-directional antenna 10 may have a reasonable structure, and the manufacturing cost and difficulty of the monopole 200 can be reduced, such that the manufacturing cost and difficulty of vertically polarized omni-directional antenna 10 can be reduced.

In some embodiments, a primary surface of each radiating portion 220 may be configured as a flat surface or a curved surface. The primary surface of the radiating portion 220 is the surface of the radiating portion 220 with the largest area. Each radiating portion 220 may have a shape of a regular polygon (such as a rectangle) or an irregular polygon. Each radiating portion 220 may be perpendicular to the base plate 100, in other words, the primary surface of each of the radiating portions 220 may be perpendicular to an upper surface of the base plate 100.

The shape, structure or dimension of the radiating portions 220 may be different from or identical to one another.

As shown in Fig. 1 to Fig. 5, in one embodiment, included angles formed between adjacent radiating portions 220 may be equal to one another, in other words, the included angle formed between two adjacent radiating portions 220 is a predetermined angle, and the plurality of radiating portions 220 are arranged at equal intervals in the circumferential direction of the central portion 210. Thus, radiations of the vertically polarized omni-directional antenna 10 and the 4G dual polarized omni-directional ceiling antenna 1 in various directions are substantially equal, the radiating out-of-roundness requirement of the vertically polarized omni-directional antenna 10 and the 4G dual polarized omni-directional ceiling antenna 1 can be further satisfied, and the omni-directional radiation of the vertically polarized omni-directional antenna 10 and the 4G dual polarized omni-directional ceiling antenna 1 can be improved.

There are at least three radiating portions 220 provided. More specifically, three radiating portions 220 are provided and an included angle between two adjacent radiating portions 220 is 120 degrees.

In some embodiments, the monopole 200 may be a metal element, i.e. the monopole 200 may be made of a metal. The connecting element 400 may be a metal element as well, i.e. the connecting element 400 may be made of a metal.

In some embodiments, as shown in Fig. 1 to Fig. 5, the second portion 620 of the coaxial cable 600 is connected with the base plate 100, one of the plurality of connecting elements 400 and one of the plurality of radiating portions 220, and the coaxial cable 600 may be passed thought the base plate 100. Thus, the influence of the electricity of the shielding layer of the coaxial cable 600 on the out-of-roundness and the cross polarization of the vertically polarized omni-directional antenna 10 can be further reduced, i.e. the out-of-roundness of the vertically polarized omni-directional antenna 10 can be further decreased, and the cross polarization ratio of the vertically polarized omni-directional antenna 10 can be further increased.

More specifically, the second portion 620 of the coaxial cable 600 may be adjacent to the first portion 610 of the coaxial cable 600 and may be welded to one of the radiating portions 220, one of the connecting elements 400 (this connecting element 400 is connected to the one radiating portion 200) and the base plate 100 in turn.

In some embodiments, the first feeder 300 includes an external conductor connected with the base plate 100 and an internal conductor disposed within the external conductor. The internal conductor of the first feeder 300 is penetrated through the base plate 100 to connect with the central portion 210.

Advantageously, as shown in Fig. 2 to Fig. 5, the internal conductor of the first feeder 300 is penetrated through a central area of the base plate 100, and the coaxial cable 600 is penetrated through the central area of the base plate 100 as well. In other words, both of the internal conductor and the coaxial cable 600 are penetrated through the central area of the base plate 100 such that the first feeder 300 and the coaxial cable 600 may be formed as a whole. Thus, the influence of the electricity of the shielding layer of the coaxial cable 600 on the out-of-roundness and the cross polarization of the vertically polarized omni-directional antenna 10 can be further reduced, i.e. the out-of-roundness of the vertically polarized omni-directional antenna 10 can be further decreased, and the cross polarization ratio of the vertically polarized omni-directional antenna 10 can be further increased.

As shown in Fig. 2 to Fig. 5, a portion of the first feeder 300 located below the base plate 100 may be adjacent to a portion of the coaxial cable 600 located below the base plate 100. Thus, the influence of the electricity of the shielding layer of the coaxial cable 600 on the out-of-roundness and the cross polarization of the vertically polarized omni-directional antenna 10 can be further reduced, i.e. the out-of-roundness of the vertically polarized omni-directional antenna 10 can be further decreased, and the cross polarization ratio of the vertically polarized omni-directional antenna 10 can be further increased.

After deep studying and researching, inventors found out the reason of passive intermodulation generated by the antenna. Metal components of a conventional antenna are connected with one another directly, however, in a manufacturing practice of the antenna, it is difficult to ensure the contact surfaces between the metal components in an ideal condition, in other words, the contact surface of each metal component cannot be guaranteed to be absolutely flat, such that the contact surfaces between the metal components connected to each other cannot be contacted completely. Thus, the conventional antenna inevitably generates a passive intermodulation due to the incomplete contact between the metal components.

In some embodiments, the connecting element 400 is directly connected with the radiating portion 220 and coupled with the base plate 100. Thus, the 4G dual polarized omni-directional ceiling antenna 1 can have a higher electrical performance and a sufficient bandwidth (an operation frequency range of the 4G dual polarized omni-directional ceiling antenna 1 are at least between 806MHz-960MHz and between 1710MHz-2700MHz) , and a passive intermodulation generated by the 4G dual polarized omni-directional ceiling antenna is also reduced.

Advantageously, the vertically polarized omni-directional antenna further includes an insulating element (not shown) disposed between the connecting element 400 and the base plate 100. With the insulating element, the coupling connection between the connecting element 400 and the base plate 100 is achieved. Thus, the 4G dual polarized omni-directional ceiling antenna 1 can have a simple and reasonable structure, and the passive intermodulation generated by the 4G dual polarized omni-directional ceiling antenna 1 is also reduced.

A coupling area of the connecting element 400 and the base plate 100 is determined and adjustable depending on a performance requirement of the 4G dual polarized omni-directional ceiling antenna 1, so that the 4G dual polarized omni-directional ceiling antenna 1 can have a sufficient capacitance under a desired frequency.

In some embodiments, the base plate 100 may be a metal plate, i.e. the base plate 100 may be made of a metal. As shown in Fig. 1 and Fig. 2, the base plate 100 may be configured as a flat plate. The connecting element 400 is coupled to an upper surface of the base plate 100 which may be configured as a flat surface. A shape of the base plate 100 may be configured as a circle, an irregular polygon or a regular polygon.

Furthermore, the base plate 100 may be substantially cylindrical and defines an accommodation chamber with an open bottom, so that portions of the first feeder 300 and the coaxial cable 600 may be received within the accommodation chamber.

In an embodiment, the insulating element may be connected to both of the connecting element 400 and the base plate 100. In other words, the insulating element may be contacted with both of the connecting element 400 and the base plate 100. Thus, the 4G dual polarized omni-directional ceiling antenna can have a simple processing and a stable structure.

The insulating element may be a non-metallic gasket, and a layer of insulating varnish or a plastic film.

In some embodiments, as shown in Fig. 1 to Fig. 5, the vertically polarized omni-directional antenna 10 further includes a metal ring 500 fitted over the plurality of radiating portions 220 and separated from the plurality of the radiating portions 220, in other words, the plurality of radiating portions 220 are disposed within the metal ring 500 without contacting with the metal ring 500. By mounting the metal ring 500, mutual couplings between the vertically and horizontally polarized omni-

directional antennas

10, 20 can be reduced, and the metal ring 500 performs a function of frequency selection to further improve the out-of-roundness and the cross polarization of the vertically polarized omni-directional antenna 10 (especially in some frequency points) . After disposing the metal ring 500, the vertically polarized omni-directional antenna 10 has an out-of-roundness less than 2.5dB and a cross polarization more than 15dB.

More specifically, the metal ring 500 is not connected to any components or portions of the vertically polarized omni-directional antenna 10.

In some embodiments, as shown in Fig. 1 to Fig. 5, each of the connecting elements 400 includes an inclined portion 410, a vertical portion 420 and a horizontal portion 430. An upper end of the inclined portion 410 is directly connected to the radiating portion 220, an upper end of the vertical portion 420 is connected to a lower end of the inclined portion 410, and the horizontal portion 430 is connected to a lower end of the vertical portion 420 and coupled to the base plate 100. In other words, the vertical portion 420 is oriented or extended in the vertical direction (i.e. an up-down direction A as shown in Fig. 1 to Fig. 5) , and the horizontal portion 430 is oriented or extended in a horizontal direction. Thus, the connecting element 400 has a simple and reasonable structure.

Each of the inclined portion 410, the vertical portion 420 and the horizontal portion 430 may have a sheet-like shape.

A primary surface of the inclined portion 410 may be a flat surface or a curved surface, and the primary surface of the inclined portion 410 is the surface of the inclined portion 410 with the largest area. A primary surface of the vertical portion 420 may be a flat surface or a curved surface, and the primary surface of the vertical portion 420 is the surface of the vertical portion 420 with the largest area. A primary surface of the horizontal portion 430 may be a flat surface or a curved surface, and the primary surface of the horizontal portion 430 is the surface of the horizontal portion 430 with the largest area.

The connecting element 400 may be a metal element, i.e. the connecting element may be made of a metal. Preferably, the inclined portion 410, the vertical portion 420 and the horizontal portion 430 may be formed integrally.

In some embodiments, as shown in Fig. 1 to Fig. 4, Fig. 6 and Fig. 7, the feed network 720 further includes a central connecting element 722, each feeder line 721 has one end connected with the central connecting element 722 and is extended in a direction away from the central connecting element 722. Thus, the feed network 720 has a reasonable structure and a manufacturing difficulty of the feed network 720 is reduced.

More specifically, the central connecting element 722 may have a circular shape, i.e. a projection of the central connecting element 722 on a horizontal plane is a circle.

In some embodiments, as shown in Fig. 1 to Fig. 4, Fig. 6 and Fig. 7, each printed dipole 740 includes a left arm 741 and a right arm 742, each of the left and

right arms

741, 742 is connected with the ground plate 730. A gap 743 is formed between the left and

right arms

741, 742, and the feeder line 721 is short-circuited with one of the left and

right arms

741, 742. Thus, the printed dipole 740 has a reasonable structure.

Advantageously, terminals of the plurality of the feeder lines 721 are short-circuited in one-to-one correspondence with the plurality of the printed dipoles 740. Thus, when the coaxial cable 600 is introduced into the horizontally polarized omni-directional antenna 20, an electric current in the external conductor of the coaxial cable 600 is suppressed efficiently, and consequently the polarization isolation between the vertically and horizontally polarized omni-

directional antennas

10, 20 can be further improved.

More specifically, the terminal of one of the feeder lines 721 may be short-circuited with one of the right and left

arms

741, 742 of one of the printed dipoles 740.

In some embodiments, a short point of the feeder line 721 and the printed dipole 740 is adjacent to the gap 743. Thus, when the coaxial cable 600 is introduced into the horizontally polarized omni-directional antenna 20, the electric current in the external conductor of the coaxial cable 600 is suppressed efficiently, and consequently the polarization isolation between the vertically and horizontally polarized omni-

directional antennas

10, 20 can be further improved.

In an embodiment, there are at least three feeder lines 721 provided, correspondingly, there are at least three printed dipoles 740 provided.

Included angles formed between adjacent feeder lines 721 may be equal to one another, in other words, the included angle formed between two adjacent feeder lines 721 is a predetermined angle, and the plurality of feeder lines 721 are arranged at equal intervals in a circumferential direction of the central connecting element 722. Thus, radiations of the horizontally polarized omni-directional antenna 20 and the 4G dual polarized omni-directional ceiling antenna 1 in various directions are substantially equal, the radiating out-of-roundness requirement of the horizontally polarized omni-directional antenna 20 and the 4G dual polarized omni-directional ceiling antenna 1 can be further satisfied, and the omni-directional radiation of the horizontally polarized omni-directional antenna 20 and the 4G dual polarized omni-directional ceiling antenna 1 can be improved.

Included angles formed between adjacent printed dipoles 740 may be equal to one another, in other words, the included angle formed between two adjacent printed dipoles 740 is a predetermined angle, and the plurality of printed dipoles 740 are arranged at equal intervals in a circumferential direction of the ground plate 730. Thus, radiations of the horizontally polarized omni-directional antenna 20 and the 4G dual polarized omni-directional ceiling antenna 1 in various directions are substantially equal, the radiating out-of-roundness requirement of the horizontally polarized omni-directional antenna 20 and the 4G dual polarized omni-directional ceiling antenna 1 can be further satisfied, and the omni-directional radiation of the horizontally polarized omni-directional antenna 20 and the 4G dual polarized omni-directional ceiling antenna 1 can be improved.

More specifically, there are three feeder lines 721 provided, correspondingly, there are three printed dipoles 740 provided. Thus, the feed network 720, the ground plate 730 and the printed dipoles 740 may constitute a microstrip power divider. The included angles formed between the two adjacent feeder lines 721 and between the two adjacent printed dipoles 740 may be 120 degrees.

In some embodiments, as shown in Fig. 7, the horizontally polarized omni-directional antenna 20 further includes a metal element 750 disposed on a lower surface of the ground plate 730. With the metal element 750 disposed on the lower surface of the ground plate 730, the out-of-roundness of the horizontally polarized omni-directional antenna 20 is improved and an effect of the horizontally polarized omni-directional antenna 20 on a standing wave ratio of high frequency band of the vertically polarized omni-directional antenna 10 is reduced.

Preferably, the metal element 750 may be configured to have a triangular shape and extended in the vertical direction. In other words, the projection of the metal element 750 in a vertical plane is triangular. Thus, the out-of-roundness of the horizontally polarized omni-directional antenna 20 is further improved and the effect of the horizontally polarized omni-directional antenna 20 on a standing wave ratio of high frequency band of the vertically polarized omni-directional antenna 10 is further reduced.

In some embodiments, as shown in Fig. 6 and Fig. 7, the horizontally polarized omni-directional antenna 20 further includes a plurality of coupling branches 800, each coupling branch 800 has a first end connected with the ground plate 730 and a second end extended in a direction away from the ground plate 730. Each coupling branch 800 is disposed between two adjacent printed dipoles 740, and each printed dipole 740 is disposed between two adjacent coupling branches 800. With the plurality of coupling branches 800, isolations and pattern out-of-roundness of the horizontally polarized omni-directional antenna 20 and the 4G dual polarized omni-directional ceiling antenna can be adjustable.

Advantageously, each coupling branch 800 may be a metal element, i.e. each coupling branch 800 may be made of a metal. Each coupling branch 800 may have a bar shape.

In some embodiments, as shown in Fig. 3 and Fig. 8, the 4G dual polarized omni-directional ceiling antenna 1 further includes a support 900 disposed on the vertically polarized omni-directional antenna 10, and the horizontally polarized omni-directional antenna 20 is supported on the support 900. With the support 900, the 4G dual polarized omni-directional ceiling antenna 1 has a stable structure.

More specifically, the support 900 may be disposed on the plurality of radiating portions 220 and defines a cable hole 910 penetrated through the support 900 in the vertical direction, so as to allow the coaxial cable 600 to pass therethrough via the cable hole 910. Thus, the coaxial cable 600 can be mounted more stably, and a travel path of the coaxial cable 600 can be controlled.

Reference throughout this specification to “an embodiment, ” “some embodiments, ” “one embodiment” , “another example, ” “an example, ” “aspecific example, ” or “some examples, ” means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. Thus, the appearances of the phrases such as “in some embodiments, ” “in one embodiment” , “in an embodiment” , “in another example, ” “in an example, ” “in a specific example, ” or “in some examples, ” in various places throughout this specification are not necessarily referring to the same embodiment or example of the present invention. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

Although explanatory embodiments have been shown and described, it would be appreciated by those skilled in the art that the above embodiments cannot be construed to limit the present invention, and changes, alternatives, and modifications can be made in the embodiments without departing from spirit, principles and scope of the present invention.

Claims

A horizontally polarized omni-directional antenna, comprising:

a dielectric plate；

a feed network disposed above the dielectric plate and comprising a plurality of feeder lines；

a ground plate disposed below the dielectric plate； and

a plurality of printed dipoles disposed below the dielectric plate, each printed dipole being connected with the ground plate and defining a gap therein,

wherein the plurality of the feeder lines are coupled in one-to-one correspondence with the plurality of gaps, and the plurality of the feeder lines are short-circuited in one-to-one correspondence with the plurality of the printed dipoles.
The antenna of claim 1, wherein the feed network further comprises a central connecting element, each feeder line has one end connected with the central connecting element and is extended in a direction away from the central connecting element.
The antenna of claim 1 or 2, wherein each printed dipole comprises a left arm and a right arm, each of the left and right arms is connected with the ground plate, the gap is formed between the left and right arms, and the feeder line is short-circuited with one of the left and right arms.
The antenna of any one of claims 1-3, wherein terminals of the plurality of the feeder lines are short-circuited in one-to-one correspondence with the plurality of the printed dipoles.
The antenna of any one of claims 1-4, wherein a short point of the feeder line and the printed dipole is adjacent to the gap.
The antenna of any one of claims 1-5, wherein at least three feeder lines are provided, and at least three printed dipoles are provided.
The antenna of any one of claims 1-6, further comprising a metal element disposed on a lower surface of the ground plate.
The antenna of claim 7, wherein the metal element is configured to have a triangular shape and extended in a vertical direction.
The antenna of any one of claims 1-8, wherein the horizontally polarized omni-directional antenna further comprises a plurality of coupling branches, each coupling branch has a first end connected with the ground plate and a second end extended in a direction away from the ground plate, each coupling branch is disposed between two adjacent printed dipoles, and each printed dipole is disposed between two adjacent coupling branches.