Dual-polarization filtering base station antenna

Abstract

The invention discloses a dual-polarization base station filtering antenna without an external filtering circuit. The dual-polarization base station filtering antenna comprises a dielectric plate I, a dielectric plate II, a dielectric plate III and a reflection metal ground, four square hollow parasitic metal rings are arranged at the bottom of the dielectric plate I; two pairs of grooved rhombic antenna radiation patches are printed at the bottom of the dielectric plate II; the middle of each antenna radiation patch is hollowed out, and slotting processing is carried out on each antenna radiation patch; a cross-shaped hollow parasitic ring is printed on the top of the third dielectric plate, and the cross-shaped hollow parasitic ring and the microstrip feeder line are arranged at an angle of 45 degrees. According to the antenna, better out-of-band rejection and good frequency selection characteristics of a passband can be achieved through small changes in a non-cascade filter circuit mode, and high isolation of two ports and stable directional diagrams in the passband are achieved.

Description

Technical Field

[0001] The present application relates to the field of antennas, and in particular to a dual-polarization filtering base station antenna. Background Art

[0002] The mobile communications industry has experienced rapid development over the past few decades. From the early days of 1G to the present day of 5G, it has undergone a rapid evolution from analog to digital communications, from narrowband to broadband communications, and from low capacity to high capacity. Base station antennas play a crucial role in providing this broadband, high-speed user experience. Antennas act as converters between guided waves in transmission lines and electromagnetic waves in free space, playing a crucial role in mobile communications. Modern communication systems operate in complex and volatile environments with significant interference. Dual-polarized base station antennas can overcome multipath fading while increasing channel capacity. Modern mobile communication systems are coexisting with second, third, fourth, and fifth generation mobile communications. This requires base station antennas to provide broadband and multi-frequency coverage. This not only saves site space but also reduces costs. However, the coexistence of multiple mobile communication standards leads to mutual coupling between antennas in different frequency bands, posing a challenge to the miniaturization of high- and low-frequency antenna units.

[0003] In existing technologies, people generally achieve out-of-passband suppression by cascading a filter in front of the antenna. However, this method requires a large volume and reduces the gain of the original antenna. Summary of the Invention

[0004] The purpose of this application is to provide a dual-polarization filtering base station antenna to address the problems in the prior art that the antenna volume required for achieving out-of-passband suppression is too large and the antenna gain is reduced.

[0005] An embodiment of the present application provides a dual-polarization filtering base station antenna, comprising:

[0006] An antenna body and a metal reflective ground, wherein the antenna body comprises: a dielectric plate 1, a dielectric plate 2, and a dielectric plate 3, wherein the dielectric plate 1, the dielectric plate 2, and the dielectric plate 3 are all square dielectric plates;

[0007] Four first metal parasitic rings are printed on the bottom surface of the dielectric plate 1; four antenna radiation patches are printed on the top surface of the dielectric plate; and a second metal parasitic ring is printed on the top of the dielectric plate 3;

[0008] The dielectric plate 1, dielectric plate 2, and dielectric plate 3 are sequentially connected from top to bottom to form the antenna body; the antenna body is connected to the metal reflective ground via a coaxial line.

[0009] Optionally, the first metal parasitic ring is a square metal parasitic ring with a hollow center, and the four first metal parasitic rings are respectively printed at the four corners of the dielectric plate 1;

[0010] Two sides of each first metal parasitic ring close to a corner of the dielectric plate 1 are parallel to two sides of a corresponding corner of the dielectric plate 1;

[0011] The four first metal parasitic rings are distributed on the dielectric plate 1 in a centrally symmetrical manner.

[0012] Optionally, the antenna radiation patch is a diamond-shaped patch with a hollow center, and the four antenna radiation patches are centrally symmetrical on the second dielectric plate;

[0013] The ends of two sides of each antenna radiation patch form a slot structure, and each of the slot structures is located at a corner of the second dielectric plate;

[0014] The two sides of the slot formed on the antenna radiation patch are respectively parallel to the two sides of the two corresponding corners of the dielectric plate.

[0015] Optionally, the second metal parasitic ring is a cross-shaped metal parasitic ring with a hollow center;

[0016] Optionally, the first metal parasitic ring is placed symmetrically with the antenna radiation patch; a microstrip feed line group is also printed on the second top surface of the dielectric plate; and the microstrip feed line group consists of two clamp-shaped microstrip feed lines.

[0017] Optionally, the second dielectric plate further includes two metal short-circuit posts, and the two clamp-shaped microstrip library wires are connected via the metal short-circuit posts to achieve bridge processing.

[0018] Optionally, the coaxial line is fixed to the bottom of the metal reflective ground, and the coaxial line includes an inner core and an outer conductor included on the surface of the inner core;

[0019] The top of the outer conductor is connected to the bottom of the dielectric plate 3 to achieve a grounding effect; the top of the inner core passes through the bottom of the dielectric plate 3 and is connected to the end of the microstrip feeder;

[0020] Optionally, the antenna radiation patch is a dipole patch antenna, and the bandwidth height of the dual-polarization filtering base station antenna is less than 0.25 times the wavelength of its operating center frequency.

[0021] The beneficial effects of the embodiments of the present invention compared with the prior art are: the antenna can achieve better out-of-band suppression and good frequency selection characteristics with minor modifications by not cascading the filtering circuit, achieve high isolation of the two ports and a stable radiation pattern within the passband, and at the same time have the characteristics of high gain, high isolation, and wide operating bandwidth. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1A three-dimensional structural diagram of a dual-polarization filtering base station antenna provided in an embodiment of the present application;

[0023] Figure 2 An exploded diagram of a dual-polarization filtering base station antenna provided in an embodiment of the present application;

[0024] Figure 3 A schematic diagram of the structure of three dielectric plates of a dual-polarization filtering base station antenna provided in an embodiment of the present application;

[0025] Figure 4 A gain simulation curve of a dual-polarization filtering base station antenna provided in an embodiment of the present application operating in the 3.1 GHz-5.6 GHz frequency band;

[0026] Figure 5 A reflection coefficient simulation curve of a dual-polarization filtering base station antenna provided in an embodiment of the present application operating in the 3.1 GHz-5.6 GHz frequency band;

[0027] Figure 6 This is a simulation curve of the isolation of a dual-polarization filtering base station antenna provided in an embodiment of the present application operating in the 3.1 GHz-5.6 GHz frequency band;

[0028] Figure 7 This is a radiation pattern of a dual-polarization filtering base station antenna provided in an embodiment of the present application;

[0029] Figure 8 This is a schematic diagram of the movement of the radiation zero point of a dual-polarization filtering base station antenna with the size of the square parasitic ring spacing provided by an embodiment of the present application;

[0030] Reference numerals: dielectric plate 1 1, dielectric plate 2 2, dielectric plate 3 3, rectangular metal reflective ground 4, square metal parasitic ring 5, antenna radiation patch 6, slotted structure slot 7, cross metal parasitic ring 8, metal short-circuit post 9, microstrip feeder group 10, outer conductor 11, inner core 12 DETAILED DESCRIPTION

[0031] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0032] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0033] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0035] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] like Figure 1 、 Figure 2 As shown, an embodiment of the present invention provides a dual-polarization filtering base station antenna, which includes an antenna body and a metal reflective ground 4, wherein the antenna body includes a dielectric plate 1, a dielectric plate 2, and a dielectric plate 3; four first metal parasitic rings 5 ​​are printed on the bottom surface of the dielectric plate 1; four antenna radiation patches 6 are printed on the top surface of the dielectric plate 2; a second metal parasitic ring 8 is printed on the top of the dielectric plate 3; the dielectric plate 1, the dielectric plate 2, and the dielectric plate 3 are connected in sequence from top to bottom to form the antenna body; the antenna body is connected to the metal reflective ground 4 through a coaxial line.

[0037] Specifically, such as Figure 3 The left side shows a preferred embodiment of a dielectric plate-1, wherein the first metal parasitic ring 5 is a square metal parasitic ring with a hollow center. Four first metal parasitic rings 5 ​​are printed at the four corners of the dielectric plate-1. The two sides of each first metal parasitic ring near the corner of the dielectric plate-1 are parallel to the two sides of the corresponding corner of the dielectric plate-1. The four first metal parasitic rings 5 ​​are distributed symmetrically around the dielectric plate-1. Through the coupling of these four square metal parasitic rings with the antenna radiating patch, a current with a direction opposite to the main polarization of the antenna radiating patch appears at 5.76 GHz, creating a radiation null point and effectively enhancing the filtering characteristics at this point.

[0038] When the antenna is working, the current is most densely distributed at the edge of the antenna radiation patch, so the resonance point can be moved by controlling the distance between the four radiation patches, thereby widening the working bandwidth. Figure 3 The right side shows a preferred embodiment of dielectric plate 2, wherein the antenna radiating patch 6 is a diamond-shaped patch with a hollow center. The four antenna radiating patches 6 are centrally symmetrical on dielectric plate 2. Each antenna radiating patch 6 has slotted structures at the ends of two of its sides, and each slotted structure is located at a corner of dielectric plate 2. The two slotted sides of the antenna radiating patch 6 are parallel to the two sides at the corresponding corners of dielectric plate 2. This slotted structure changes the current path of the antenna radiating patch, generating a current opposite to the main polarization direction at 2.72 GHz, thereby creating a radiation null and effectively enhancing the filtering effect.

[0039] Specifically, such as Figure 3 The middle figure shows a preferred embodiment of the dielectric plate 3, wherein the second metal parasitic ring 8 is a cross-shaped metal parasitic ring with a hollow center.

[0040] Please refer to the figure. As a preferred embodiment, the first metal parasitic ring printed on the dielectric plate 1 is symmetrically placed with the antenna radiation patch 6 printed on the dielectric plate 2. A microstrip feed line group 8 is also printed on the top surface of the dielectric plate 2. The microstrip feed line group 8 consists of two clamp-shaped microstrip feed lines. The microstrip feed line group provided in the embodiment of the present invention reduces the feeding area for the antenna radiation patch 6, improves impedance matching, and thus increases the radiation characteristics.

[0041] Furthermore, as a preferred embodiment, the dielectric plate 2 further includes two metal short-circuit posts. In order to avoid the two microstrip feed lines from crossing and forming a short circuit, the two microstrip feed lines are connected by the metal short-circuit posts to achieve bridge processing.

[0042] Furthermore, as a preferred embodiment, by coupling the cross parasitic ring of the dielectric plate three 3 with the antenna radiation patch on the dielectric plate two 2, the current path through the parasitic ring is changed, and radiation zero points are generated at 2.06GHz and 6.87GHz, respectively, thereby effectively enhancing the filtering characteristics of the antenna without increasing the volume of the antenna.

[0043] Please continue to see Figure 1 、 Figure 2A rectangular metal reflective ground 4 is set directly below the dielectric plate 3, and the rectangular metal reflective ground 4 can reflect the electromagnetic waves of the antenna and enhance the gain; the coaxial line is fixed to the bottom of the metal reflective ground 4. Specifically, two holes are opened in the middle of the rectangular metal ground for welding and fixing two coaxial lines. The coaxial line includes an inner core 12 and an outer conductor 11 included on the surface of the inner core 12; the top of the outer conductor 11 is connected to the bottom of the dielectric plate 3 3, so that the antenna radiation patch can be contacted and grounded with the metal reflective ground; the top of the inner core 12 passes through the bottom of the dielectric plate 3 3 and is connected to the end of the microstrip feed line, so that energy transmission between the microstrip feed line and the antenna radiation patch is achieved in a coupled feeding manner, thereby achieving the effect of expanding the working bandwidth.

[0044] As a preferred embodiment, the antenna radiation patch is a dipole patch antenna, and the bandwidth height of the dual-polarization filtering base station antenna is less than 0.25 times the wavelength of its operating center frequency.

[0045] See Figure 4 When the operating frequency of the dual-polarization filtering base station antenna is between 3GHz and 5.6GHz, the average in-band gain reaches 8.5db, achieving the high gain of the dual-polarization filtering base station antenna.

[0046] See Figure 5 , the reflection coefficient of the two ports of the dual-polarization filtering base station antenna is less than -10db within the working frequency band;

[0047] See Figure 6 The isolation between the two ports of the dual-polarization filtering base station antenna within the working frequency band is greater than 25db, achieving a high internal isolation;

[0048] See Figure 7 The antenna has a stable main polarization pattern at 3.1GHz, 4.6GHz and 5.1GHz, and the cross-polarization is less than -20db.

[0049] See Figure 8 The antenna radiation zero point moves with the size of the square parasitic ring spacing.

[0050] The dual-polarization filtering base station antenna described in the embodiment of the present invention can change the radiation characteristics of the dual-polarization filtering base station antenna by placing the cross metal parasitic ring 8 directly below the diamond-shaped hollow antenna radiation patch 6. When the antenna is working, the two are coupled, which can produce better filtering effect. At the same time, by providing a slot structure on the diamond-shaped radiation patch 6, the current path is changed, and two radiation zero points are generated at high and low frequencies respectively, thereby further obtaining better filtering characteristics without affecting the gain, thereby achieving miniaturization of the array. Furthermore, by loading four square metal parasitic rings 5 ​​above the diamond-shaped radiation patch 6, new radiation zero points are further introduced at high frequencies, and the problem of poor impedance matching caused by the slotting of the antenna radiation patch 6 is solved, so that the dual-polarization filtering base station antenna can be used in the 5G operating frequency band. The dual-polarization filtering base station antenna provided in this embodiment has high gain, high isolation, wide operating bandwidth and maintains a stable directional pattern, which is conducive to the realization of a broadband base station antenna array.

[0051] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A dual-polarization filtering base station antenna, characterized in that: include: An antenna body and a metal reflective ground (4), wherein the antenna body comprises: a dielectric plate 1 (1), a dielectric plate 2 (2) and a dielectric plate 3 (3), and the dielectric plate 1 (1), the dielectric plate 2 (2) and the dielectric plate 3 (3) are all square dielectric plates; The bottom surface of the dielectric plate 1 (1) is printed with four first metal parasitic rings (5); the top surface of the dielectric plate (2) is printed with four antenna radiation patches (6); the top surface of the dielectric plate 3 (3) is printed with a second metal parasitic ring (8); The dielectric plate 1 (1), dielectric plate 2 (2), and dielectric plate 3 (3) are sequentially connected from top to bottom to form the antenna body; the antenna body is connected to the metal reflective ground (4) via a coaxial line.

2. The dual-polarization filtering base station antenna according to claim 1, characterized in that: The first metal parasitic ring (5) is a square metal parasitic ring with a hollow center, and the four first metal parasitic rings are respectively printed at the four corners of the dielectric plate (1); The two sides of each first metal parasitic ring close to the corner of the dielectric plate (1) are parallel to the two sides of the corresponding corner of the dielectric plate (1); The four first metal parasitic rings (5) are distributed on the dielectric plate (1) in a centrally symmetrical manner.

3. The dual-polarization filtering base station antenna according to claim 1, wherein: The antenna radiation patch (6) is a diamond-shaped patch with a hollow center, and the four antenna radiation patches (6) are centrally symmetrical on the second dielectric plate (2); The ends of two sides of each antenna radiation patch (6) form a slot structure, and each slot structure is located at a corner of the dielectric plate (2); The antenna radiation patch (6) forms two slotted sides, which are respectively parallel to the two sides of the second (2) corresponding corner of the dielectric plate.

4. The dual-polarization filtering base station antenna according to claim 1, characterized in that: The second metal parasitic ring (8) is a cross-shaped metal parasitic ring with a hollow center.

5. The dual-polarization filtering base station antenna according to claim 1, characterized in that: The first metal parasitic ring (5) and the antenna radiation patch (6) are placed symmetrically; a microstrip feeder group (10) is also printed on the top surface of the second dielectric plate (2); the microstrip feeder group (10) consists of two clamp-shaped microstrip feeders.

6. The dual-polarization filtering base station antenna according to claim 5, characterized in that: The dielectric plate 2 (2) further includes a metal short-circuit column (9), and the two clamp-shaped microstrip feed lines are connected via the metal short-circuit column to achieve bridge processing.

7. The dual-polarization filtering base station antenna according to claim 6, characterized in that: The coaxial line is fixed to the bottom of the metal reflective ground (4), and the coaxial line includes an inner core (12) and an outer conductor (11) included on the surface of the inner core; The top of the outer conductor (11) is connected to the bottom of the dielectric plate three (3) to achieve a grounding effect; the top of the inner core (12) passes through the bottom of the dielectric plate three (3) and is connected to the end of the microstrip feeder.

8. The dual-polarization filtering base station antenna according to any one of claims 1 to 7, characterized in that: The antenna radiation patch is a dipole patch antenna, and the bandwidth height of the dual-polarization filtering base station antenna is less than 0.25 times the wavelength of its operating center frequency.

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