Electromagnetic transparent dual polarized base station antenna

Abstract

The application is an electromagnetic transparent dual-polarized base station antenna. The application relates to the technical field of mobile communication, and the antenna comprises a first radiator, a second radiator, a third radiator, a fourth radiator, a dielectric substrate, a first balun feed structure, a second balun feed structure and a common metal ground layer. Compared with the prior art, the application can realize the coverage of the two 5G frequency bands of 3.3-3.8GHz and 4.8-5GHz through opening various types of slots on the radiators, and the antenna itself can work in the 1.7-2.7GHz frequency band. Under the condition of the radiation of the lower high-frequency antenna, the slots on the radiators generate opposite cancellation currents, and the secondary radiation generated by the currents can be offset, so that the shielding effect on the radiation of the lower high-frequency antenna is not generated.

Description

Technical Field

[0001] This invention relates to the field of mobile communication technology and is an electromagnetically transparent dual-polarized base station antenna. Background Technology

[0002] As demands for communication capacity, speed, and latency continue to increase, communication technologies are constantly iterating, leading to a continuous increase in the number of antennas in base station antennas and ever-larger array sizes. The rising frequency bands allocated by these technological advancements reduce the coverage area of ​​corresponding base station antennas, necessitating increased base station density to achieve the same coverage as previous generations. This has significantly increased the demand for the construction of various encrypted base stations and indoor base stations.

[0003] On the other hand, the transition of communication standards is not something that can be achieved overnight, and base stations must meet the usage needs of users with different communication standards. Therefore, 5G communication systems need to be compatible with previous 2G / 3G / 4G communication systems. Due to the limited space resources on base stations, 2G / 3G / 4G antennas are already deployed in the optimal positions of the base station's radiation aperture, and often antennas of different frequency bands share the same aperture to improve the base station.

[0004] Traditional base station antennas suffer from severe inter-array coupling when deployed densely, and there are also cross-band mutual coupling between antennas of different frequency bands. Furthermore, there are issues such as the low-frequency antenna above blocking the radiation of the high-frequency antenna below. These problems cause the antenna's radiation performance to decrease or even deteriorate compared to its performance when radiating alone.

[0005] Therefore, developing new base station antenna unit structures to achieve electromagnetic transparency of antenna units to other frequency band antenna units that are blocked by their radiation is an effective way to alleviate the shortage of base station site space resources, improve the overall network efficiency and user experience, and promote the development of mobile communications without sacrificing performance. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides an electromagnetically transparent dual-polarized base station antenna. The coaxial feed structure of this invention avoids the use of any wire bridges, short-circuit pins, or feed probes, making the dual-polarized antenna feed structure simple and reducing manufacturing costs.

[0007] This invention provides the following technical solutions:

[0008] An electromagnetically transparent dual-polarized base station antenna, the antenna comprising: a first radiator, a second radiator, a third radiator, a fourth radiator, a dielectric substrate, a first balun feed structure, a second balun feed structure, and a common metallic ground layer;

[0009] The first balun feed structure and the second balun feed structure are printed on the front side of the dielectric substrate. The first balun feed structure is located behind and connected to the first and third radiators, and the second balun feed structure is located behind and connected to the second and fourth radiators. The two feed baluns are vertically embedded and embedded in a common metal ground layer. The balun feed structure is fed by a coaxial line under the common metal ground layer.

[0010] The common metallic stratum is used to reflect the downward radiation energy of the first, second, third, and fourth radiators and is connected to the backplate of the first and second balun feed structures as ground.

[0011] Preferably, the radiator is obtained by chamfering and opening a series of shaped grooves on a circular patch, wherein the groove shapes include: rectangular long grooves, pincer-shaped grooves and fan-shaped narrow grooves.

[0012] Preferably, the rectangular slot is located at the diameter of the circular radiator, and its directional angle is consistent with the ±45° dual polarization direction of the antenna;

[0013] The clamp slots are attached to the diameter and outer circumference of the circular radiator. There are two clamp slots in a quarter circle unit of the antenna radiator. One side of the clamp slot is attached to the rectangular long slot, and the other side is attached to one side of another clamp slot. The two clamp slots form a quarter fan shape.

[0014] The fan-shaped groove is a groove cut into the inner patch of the fan-shaped patch formed by the previously mentioned clamp-shaped groove.

[0015] Preferably, the polarization of the radiator in two directions is fed by two balun feeding structures respectively; the two balun feeding structures are printed on two dielectric substrates respectively, the other side of the dielectric substrate is a common metal ground layer, and the middle is separated by interlocking. The two dielectric substrates are perpendicular to each other and placed perpendicular to the common metal ground layer; one dielectric substrate has a groove in the lower half and the other dielectric substrate has a groove in the upper half, and the two can be interlocked perpendicularly to each other.

[0016] Preferably, the balun feed structure is "Γ" shaped, and the structures near the two balun feed structures are connected by a semi-circular ring to reduce mutual interference between the baluns.

[0017] The balun-fed structure adds a branch to the overall "Γ" shape. The polarization of the radiator in two directions is fed by two coaxial lines respectively. A pair of dipole units responsible for radiation in one polarization direction are printed on the upper and lower surfaces of the dielectric substrate respectively.

[0018] Preferably, in one polarization direction, the outer conductor of the coaxial line is connected to one of a pair of dipoles located on the lower surface of the dielectric substrate, and the other of the pair of dipoles located on the upper surface of the dielectric substrate extends a microstrip stub to the coaxial line position, and the inner conductor is connected to it.

[0019] In another polarization direction, one of the dipoles on the lower surface of the dielectric substrate extends a microstrip stub to below the other of the dipoles on the upper surface of the dielectric substrate. The inner conductor of the coaxial line is connected to the dipole on the lower surface of the dielectric substrate, while the outer conductor is connected to the dipole on the upper surface of the dielectric substrate.

[0020] Preferably, the inner conductor is connected to the lower radiator of the dielectric substrate, and its stub extension length does not completely cover the coaxial line. The remaining part of the outer conductor can bypass the stub and connect to the upper radiator of the dielectric substrate. In the sector dipole unit, the inner corners are all chamfered.

[0021] A base station antenna includes an electromagnetically transparent dual-polarized base station antenna and a reflector, the reflector being disposed behind the electromagnetically transparent dual-polarized base station antenna and used for its directional radiation.

[0022] A tri-band base station antenna ， The antenna includes an electromagnetically transparent dual-polarized base station antenna and another dual-band antenna placed coaxially below the electromagnetically transparent antenna. The overall antenna structure can cover three frequency bands: 1.7-2.7GHz, 3.3-3.8GHz, and 4.8-5GHz. Each frequency band can radiate normally, and the interference between frequency bands is minimal.

[0023] A design method for an electromagnetically transparent dual-polarized base station antenna, characterized in that: the method is based on a magnetically transparent dual-polarized base station antenna. 。

[0024] The present invention has the following beneficial effects:

[0025] Compared with the prior art, the present invention:

[0026] Compared to existing technologies, this invention achieves electromagnetic transparency coverage of the 3.3-3.8GHz and 4.8-5GHz 5G frequency bands by creating various types of slots on the radiator, while the antenna itself can operate in the 1.7-2.7GHz frequency band. Under the condition of radiation from the high-frequency antenna below, the slots on the radiator generate opposing canceling currents, and the secondary radiation generated by the current cancels each other out, thus not blocking the radiation of the high-frequency antenna below.

[0027] In terms of feeding structure, the balun feeding structure is stable and robust, requiring no additional nylon pillars or other fixing methods. Balun feeding can provide multiple resonant points within the band, ensuring stable in-band matching coefficients. Simultaneously, the additional filter stub design reduces interference to high-frequency antennas and eliminates the space required for additional filters on the base station.

[0028] The coaxial feed structure avoids the use of any wire bridges, short-circuit pins or feed probes, making the dual-polarized antenna feed structure simple and reducing manufacturing costs. Attached Figure Description

[0029] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 The diagram shown is a schematic diagram of the electromagnetic transparent dual-polarized base station antenna unit structure of the present invention.

[0031] Figure 2 The diagram shown is a top view of the electromagnetic transparent dual-polarized base station antenna radiator of the present invention.

[0032] Figure 3 The diagram shown is a side view of the electromagnetic transparent dual-polarized base station antenna radiator of the present invention.

[0033] Figure 4 The diagram shown is a schematic diagram of the electromagnetic transparent dual-polarized coaxial tri-band base station antenna structure of the present invention.

[0034] Figure 5 The diagram shows the electromagnetic transparent dual-polarized base station antenna unit and high-frequency antenna array structure of the present invention.

[0035] Figure 6 The following are the port S-parameters of the balun-fed electromagnetic transparent dual-polarized base station antenna unit of the present invention.

[0036] Figure 7 The following are the port S-parameters of the coaxial-fed electromagnetic transparent dual-polarized base station antenna of the present invention.

[0037] Figure 8 The actual gain of the balun-fed electromagnetic transparent dual-polarized base station antenna of the present invention is shown.

[0038] Figure 9 The image shows a gain comparison of the electromagnetic transparent dual-polarized coaxial tri-band base station antenna of the present invention. Detailed Implementation

[0039] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0041] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0042] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0043] The present invention will be described in detail below with reference to specific embodiments. Specific Implementation Example 1:

[0045] To address the shortcomings of existing technologies, this invention provides an electromagnetically transparent dual-polarized base station antenna:

[0046] according to Figures 1 to 9 As shown:

[0047] An electromagnetically transparent dual-polarized base station antenna, the antenna comprising: a first radiator 1, a second radiator 2, a third radiator 3, a fourth radiator 4, a dielectric substrate 5, a first balun feed structure 6, a second balun feed structure 7, and a common metallic ground layer 8;

[0048] The first balun feed structure 6 and the second balun feed structure 7 are printed on the front side of the dielectric substrate 5. The first balun feed structure 6 is located behind and connected to the first radiator 1 and the third radiator 3, and the second balun feed structure 7 is located behind and connected to the second radiator 2 and the fourth radiator 4. The two feed baluns are vertically embedded and embedded in the common metal ground layer 8. The balun feed structure is fed by a coaxial line under the common metal ground layer 8.

[0049] The common metallic stratum 8 is used to reflect the downward radiation energy of the first radiator 1, the second radiator 2, the third radiator 3, and the fourth radiator 4, and is connected to the back plate of the first balun feed structure 6 and the second balun feed structure 7 as ground.

[0050] This invention achieves electromagnetic transparency coverage of the 3.3-3.8GHz and 4.8-5GHz 5G frequency bands by creating various types of slots on the radiator, while the antenna itself can operate in the 1.7-2.7GHz frequency band. Under the condition of radiation from the high-frequency antenna below, the slots on the radiator generate canceling currents in opposite directions, and the secondary radiation generated by the current cancels each other out, thus not blocking the radiation of the high-frequency antenna below.

[0051] In terms of the feeding structure, this invention features a stable and robust balun feeding structure that eliminates the need for additional nylon pillars or other fixing methods. The balun feeding can provide multiple resonant points within the band, ensuring stable in-band matching coefficients. Simultaneously, the additional filter stub design reduces interference to high-frequency antennas and eliminates the space required for additional filters on the base station.

[0052] The coaxial feed structure of this invention avoids the use of any wire bridges, short-circuit pins or feed probes, making the dual-polarized antenna feed structure simple and reducing manufacturing costs. Specific Implementation Example 2:

[0054] The only difference between Embodiment 2 and Embodiment 1 of this application is that:

[0055] The radiator is obtained by chamfering and opening a series of shaped grooves on a circular patch, including rectangular long grooves, pincer-shaped grooves and fan-shaped narrow grooves. Specific Implementation Example 3:

[0057] The only difference between Embodiment 3 and Embodiment 2 of this application is that:

[0058] The rectangular slot is located at the diameter of the circular radiator, and its directional angle is consistent with the ±45° dual polarization direction of the antenna.

[0059] The clamp slots are attached to the diameter and outer circumference of the circular radiator. There are two clamp slots in a quarter circle unit of the antenna radiator. One side of the clamp slot is attached to the rectangular long slot, and the other side is attached to one side of another clamp slot. The two clamp slots form a quarter fan shape.

[0060] The fan-shaped groove is a groove cut into the inner patch of the fan-shaped patch formed by the previously mentioned clamp-shaped groove. Specific Implementation Example 4:

[0062] The only difference between Embodiment 4 and Embodiment 3 of this application is that:

[0063] The polarization of the radiator in two directions is fed by two balun feeding structures. The two balun feeding structures are printed on two dielectric substrates. The other side of the dielectric substrate is a common metal ground layer. The two dielectric substrates are separated by interlocking. The two dielectric substrates are perpendicular to each other and placed perpendicular to the common metal ground layer. One dielectric substrate has a groove in the lower half and the other dielectric substrate has a groove in the upper half. The two can be interlocked perpendicularly. Specific Implementation Example 5:

[0065] The difference between Embodiment 5 and Embodiment 4 of the present invention lies only in:

[0066] The balun feed structure is "Γ" shaped, and the structures near the two balun feed structures are connected by a semi-circular ring to reduce mutual interference between the baluns.

[0067] The balun-fed structure adds a branch to the overall "Γ" shape. The polarization of the radiator in two directions is fed by two coaxial lines respectively. A pair of dipole units responsible for radiation in one polarization direction are printed on the upper and lower surfaces of the dielectric substrate respectively. Specific Implementation Example Six:

[0069] The difference between Embodiment Six and Embodiment Five of the present invention lies only in:

[0070] In one polarization direction, the outer conductor of the coaxial line is connected to one of a pair of dipoles located on the lower surface of the dielectric substrate, and the other of the pair of dipoles located on the upper surface of the dielectric substrate extends a microstrip stub to the coaxial line position, and the inner conductor is connected to it.

[0071] In another polarization direction, one of the dipoles on the lower surface of the dielectric substrate extends a microstrip stub to below the other of the dipoles on the upper surface of the dielectric substrate. The inner conductor of the coaxial line is connected to the dipole on the lower surface of the dielectric substrate, while the outer conductor is connected to the dipole on the upper surface of the dielectric substrate. Specific Implementation Example 7:

[0073] The difference between Embodiment Seven and Embodiment Six of the present invention lies only in:

[0074] The inner conductor is connected to the lower radiator of the dielectric substrate. The extension length of its stub does not completely cover the coaxial line. The remaining part of the outer conductor can bypass the stub and connect to the upper radiator of the dielectric substrate. In the sector dipole unit, the inner corners are all chamfered. Specific Implementation Example 8:

[0076] The difference between Embodiment 8 and Embodiment 7 of the present invention lies only in:

[0077] The present invention provides a base station antenna, the antenna comprising an electromagnetically transparent dual-polarized base station antenna and a reflector, the reflector being disposed behind the electromagnetically transparent dual-polarized base station antenna and used for its directional radiation. Specific Implementation Example Nine:

[0079] The difference between Embodiment Nine and Embodiment Eight of the present invention lies only in:

[0080] This invention provides a tri-band base station antenna ， The antenna includes an electromagnetically transparent dual-polarized base station antenna and another dual-band antenna placed coaxially below the electromagnetically transparent antenna. The overall antenna structure can cover three frequency bands: 1.7-2.7GHz, 3.3-3.8GHz, and 4.8-5GHz. Each frequency band can radiate normally, and the interference between frequency bands is minimal. Specific Implementation Example 10:

[0082] The only difference between Embodiment 10 and Embodiment 9 of the present invention is that:

[0083] This invention provides a design method for an electromagnetically transparent dual-polarized base station antenna, characterized in that the method is based on a magnetically transparent dual-polarized base station antenna.

[0084] This invention achieves electromagnetic transparency coverage of the 3.3-3.8GHz and 4.8-5GHz 5G frequency bands by creating various types of slots on the radiator, while the antenna itself can operate in the 1.7-2.7GHz frequency band. Under the condition of radiation from the high-frequency antenna below, the slots on the radiator generate canceling currents in opposite directions, and the secondary radiation generated by the current cancels each other out, thus not blocking the radiation of the high-frequency antenna below.

[0085] In terms of the feeding structure, this invention features a stable and robust balun feeding structure that eliminates the need for additional nylon pillars or other fixing methods. The balun feeding can provide multiple resonant points within the band, ensuring stable in-band matching coefficients. Simultaneously, the additional filter stub design reduces interference to high-frequency antennas and eliminates the space required for additional filters on the base station.

[0086] The coaxial feed structure of this invention avoids the use of any wire bridges, short-circuit pins or feed probes, making the dual-polarized antenna feed structure simple and reducing manufacturing costs. Specific Implementation Example Eleven:

[0088] The only difference between Embodiment Eleven and Embodiment Ten of this invention is that:

[0089] See Figure 1The core of this invention is to provide an electromagnetically transparent dual-polarized base station antenna unit, including a first radiator 1, a second radiator 2, a third radiator 3, a fourth radiator 4, a dielectric substrate 5, a first balun feed structure 6, a second balun feed structure 7, and a common metallic ground layer 8.

[0090] The first balun feed structure 6 is located behind and connected to the first radiator 1 and the third radiator 3, and the second balun feed structure 7 is located behind and connected to the second radiator 2 and the fourth radiator 4. The two feed baluns are vertically embedded and embedded in a common metallic ground layer 8, which is fed by a coaxial line. The common metallic ground layer 8 is used to reflect the downward radiation energy of the radiators and is connected to the backplate opposite to the first balun feed structure 6 and the second balun feed structure 7 as ground.

[0091] The specific structure and parameters of the radiator are as follows: Figure 2 As shown. The radiator is obtained by opening various types of slots on the fan-shaped patch, including: a clamp-shaped slot 9 attached to the edge of the fan-shaped patch, a rectangular long slot 10 along the radial line, and a fan-shaped long slot 11 placed inside and attached to the clamp-shaped slot.

[0092] The main parameters of the radiator are as follows: dipole radius R1 = 30 mm, dipole patch spacing W0 = 0.6 mm, rectangular long slot width W1 = 0.5 mm, one side slot width of the clamp-shaped slot W2 = 4.5 mm, the middle slot width of the clamp-shaped slot W3 = 0.7 mm, and the other side slot width of the clamp-shaped slot W4 = 1.2 mm.

[0093] Figure 3 The specific structure of the two balun feeds is shown. The balun feed structure is printed on the front of the dielectric substrate, and a metal backplate is printed on the back. The dielectric substrate has a slot in the middle to allow for interlocking. A rectangular protrusion on the top is used to fix the radiators on it. The intersection of the balun feed structures in the middle is rounded, and filter stubs extend from the main feed arm. Feeding is achieved at the bottom via a coaxial line. The metal backplate is connected to a common metal ground layer 8. Specific Implementation Example Twelve:

[0095] The only difference between Embodiment Twelve and Embodiment Eleven of the present invention is that:

[0096] Figure 4This paper presents an electromagnetically transparent dual-polarized coaxial tri-band base station antenna structure. The antenna is based on the aforementioned electromagnetically transparent dual-polarized base station antenna unit, but with a coaxial feed line and a high-frequency antenna placed coaxially below. The high-frequency antenna consists of two dielectric substrates, a differentially fed coaxial feed line, a radiator on the upper surface of the dielectric substrate, a radiator on the lower surface of the dielectric substrate, and a radiator on the lower surface of the dielectric substrate. The main function of the radiator is to extend the bandwidth. This high-frequency antenna has a wide radiation bandwidth, covering the 3.3-3.8 GHz and 4.8-5 GHz 5G frequency bands. This electromagnetically transparent dual-polarized coaxial tri-band base station antenna can cover three typical communication frequency bands: 1.7-2.7 GHz, 3.3-3.8 GHz, and 4.8-5 GHz. Because the uppermost electromagnetically transparent radiator is electromagnetically transparent to the 3.3-3.8 GHz and 4.8-5 GHz frequency bands, the lower high-frequency antenna can radiate normally in these two frequency bands without obstruction. This electromagnetically transparent dual-polarized coaxial tri-band base station antenna will greatly improve the space utilization of the base station.

[0097] Example 3

[0098] Figure 5 This study demonstrates a periodic element array composed of an electromagnetically transparent dual-polarized base station antenna and four high-frequency antennas. The array consists of one electromagnetically transparent dual-polarized base station antenna and four high-frequency base station antennas. This periodic element can be periodically extended in the x or y direction to form a larger base station antenna array. This is equivalent to inserting electromagnetically transparent dual-polarized base station antennas at intervals within a high-frequency antenna array, while both types of antennas can operate normally in their respective frequency bands. Compared to traditional base station configurations that group antenna arrays of different frequency bands horizontally, this array arrangement saves more base station space.

[0099] Figure 6 Simulation results of S-parameters for the feed port of a balun-fed electromagnetic transparent dual-polarized base station antenna are presented. S11 and S22 represent the port reflection coefficients. The reflection coefficients are below -15dB in the 1.7-2.7GHz frequency band, indicating excellent antenna matching within this band. S12 and S21 represent the isolation coefficients between the two polarized feed ports. The isolation coefficients are both below -30dB in the 1.7-2.7GHz frequency band, indicating excellent isolation between the two polarized feed ports.

[0100] Figure 7 Simulation results of S-parameters for the feed port of a coaxially fed electromagnetic transparent dual-polarized base station antenna are presented. S11 and S22 represent the reflection coefficients of the ports. The reflection coefficients are below -10dB in the 1.7-2.7GHz frequency band, indicating excellent antenna matching within this band. S12 and S21 represent the isolation coefficients between the two polarized feed ports. The isolation coefficients are approximately -30dB in the 1.7-2.7GHz frequency band, indicating excellent isolation between the two polarized feed ports.

[0101] Figure 8 Simulation results of the actual gain of the electromagnetically transparent dual-polarized base station antenna fed by a balun. As shown in the figure, the actual antenna gain is stable within the operating frequency band of 1.7-2.7 GHz, basically around 8 dBi. Due to the addition of a filter in the balun structure, it can be observed that after 3 GHz, the actual antenna gain drops sharply to below 0 dBi, reducing the radiated interference of the antenna to high-frequency antennas on the base station.

[0102] Figure 9 The figure compares the actual gain of a standalone high-frequency antenna and an electromagnetically transparent dual-polarized base station antenna above it in the 3.3-3.8 GHz and 4.8-5 GHz frequency bands. As shown in the figure, after the high-frequency antenna radiation passes through the electromagnetically transparent dual-polarized base station antenna, the actual gain decreases in the 4.0-4.7 GHz band due to obstruction, while the actual gain in the 3.3-4.0 GHz band is on average consistent with the actual gain of the standalone high-frequency antenna, with some areas showing an improvement. In the 4.8-5 GHz band, the actual gain is only slightly lower than that of the standalone high-frequency antenna. Overall, the actual gain is higher than 8.5 dB in both the 3.3-3.8 GHz and 4.8-5 GHz bands. This indicates that the electromagnetically transparent antenna does indeed achieve electromagnetic transparency in these two frequency bands. Specific Implementation Example Thirteen:

[0104] The only difference between Embodiment Thirteen and Embodiment Twelve of the present invention is that:

[0105] To address the problems in the background art, the present invention provides an electromagnetically transparent dual-polarized base station antenna unit, which, from top to bottom, consists of a radiator, a dielectric substrate, a feeding structure, and a common metallic ground layer.

[0106] The radiator is obtained by chamfering and opening a series of shaped grooves on a circular patch, wherein the groove shapes include: long rectangular grooves, pincer-shaped grooves and fan-shaped narrow grooves;

[0107] The rectangular slot is located at the diameter of the circular radiator, and its directional angle is consistent with the ±45° dual polarization direction of the antenna.

[0108] The clamp-shaped slots are attached to the diameter and outer circumference of the circular radiator. There are two clamp-shaped slots within a quarter-circle unit of the antenna radiator. One side of each clamp-shaped slot is attached to the previously mentioned rectangular slot, and the other side is attached to one side of another clamp-shaped slot. The two clamp-shaped slots approximately form a quarter-sector.

[0109] The fan-shaped groove is a groove cut into the inner patch of the fan-shaped patch formed by the previously mentioned clamp-shaped groove.

[0110] The polarization of the radiator of the dual-polarized base station antenna unit in two directions can be fed by two baluns respectively.

[0111] The two baluns are printed on two dielectric substrates, one side of which is a metal ground plane, with a gap in the middle due to interlocking. The two dielectric substrates are perpendicular to each other and placed perpendicular to the metal ground plane. One dielectric substrate has a groove in its lower half, and the other dielectric substrate has a groove in its upper half, allowing them to be interlocked perpendicularly.

[0112] The shape of the balun is approximately "Γ". The structures at the close points of the two baluns are connected by a semi-circular ring, which can reduce mutual interference between the close points of the baluns.

[0113] The balun adds a branch to the overall "Γ" shape. This branch acts as a filter, which can reduce out-of-band gain above the antenna operating frequency and reduce the impact on other high-frequency gains in the base station.

[0114] The polarization of the radiator in the dual-polarized base station antenna unit can also be fed by two coaxial lines respectively; a pair of dipole units responsible for radiation in one polarization direction are printed on the upper and lower surfaces of the dielectric substrate respectively.

[0115] In one polarization direction, the outer conductor of the coaxial line is connected to one of a pair of dipoles located on the lower surface of the dielectric substrate, and the other of the pair of dipoles located on the upper surface of the dielectric substrate extends a microstrip stub to the coaxial line position, and the inner conductor is connected to it.

[0116] In another polarization direction, one of the dipoles on the lower surface of the dielectric substrate extends a microstrip stub to below the other of the dipoles on the upper surface of the dielectric substrate. The inner conductor of the coaxial line is connected to the dipole on the lower surface of the dielectric substrate, while the outer conductor is connected to the dipole on the upper surface of the dielectric substrate.

[0117] The inner conductor is connected to the lower radiator of the dielectric substrate, and its stub extension length does not completely cover the coaxial line, allowing the remaining portion of the outer conductor to bypass the stub and connect to the upper radiator of the dielectric substrate.

[0118] Preferably, the interior corners of the sector-shaped dipole unit are chamfered.

[0119] Based on the same concept, the present invention also provides a base station antenna, including at least one electromagnetically transparent dual-polarized base station antenna unit as described in any one of the above claims and a reflector, wherein the reflector is disposed behind the electromagnetically transparent dual-polarized base station antenna unit and is used for directional radiation therefrom.

[0120] Based on the same concept, the present invention also provides a tri-band base station antenna, comprising at least one of the electromagnetically transparent dual-polarized base station antenna elements described above, with another dual-band antenna placed coaxially below and with the electromagnetically transparent antenna. The overall antenna structure can cover three frequency bands: 1.7-2.7GHz, 3.3-3.8GHz, and 4.8-5GHz, with normal radiation in each band and minimal inter-band interference.

[0121] The above description is merely a preferred embodiment of an electromagnetically transparent dual-polarized base station antenna. The protection scope of an electromagnetically transparent dual-polarized base station antenna is not limited to the above embodiments; all technical solutions falling within this conceptual framework are within the protection scope of this invention. It should be noted that for those skilled in the art, any improvements and variations made without departing from the principles of this invention should also be considered within the protection scope of this invention.

Claims

1. An electromagnetically transparent dual-polarized base station antenna, characterized in that: The antenna includes: a first radiator, a second radiator, a third radiator, a fourth radiator, a dielectric substrate, a first balun feed structure, a second balun feed structure, and a common metallic ground layer; The first balun feed structure and the second balun feed structure are printed on the front side of the dielectric substrate. The first balun feed structure is located behind and connected to the first and third radiators, and the second balun feed structure is located behind and connected to the second and fourth radiators. The two feed baluns are vertically embedded and embedded in a common metal ground layer. The balun feed structure is fed by a coaxial line under the common metal ground layer. The common metallic stratum is used to reflect the downward radiation energy of the first, second, third, and fourth radiators and is connected to the back plate of the first and second balun feed structures as ground. The radiator is obtained by chamfering and opening a series of shaped grooves on a circular patch, wherein the groove shapes include: long rectangular grooves, pincer-shaped grooves and fan-shaped narrow grooves; The rectangular slot is located at the diameter of the circular radiator, and its directional angle is consistent with the ±45° dual polarization direction of the antenna. The clamp slots are attached to the diameter and outer circumference of the circular radiator. There are two clamp slots in a quarter circle unit of the antenna radiator. One side of the clamp slot is attached to the rectangular long slot, and the other side is attached to one side of another clamp slot. The two clamp slots form a quarter fan shape. The fan-shaped groove is a groove cut into the inner patch of the fan-shaped patch formed by the previously mentioned clamp-shaped groove; The polarization of the radiator in two directions is fed by two balun feed structures respectively; the two balun feed structures are printed on two dielectric substrates respectively, the other side of the dielectric substrate is a common metal ground layer, and the middle is separated by interlocking. The two dielectric substrates are perpendicular to each other and placed perpendicular to the common metal ground layer; one dielectric substrate has a groove in the lower half and the other dielectric substrate has a groove in the upper half, and the two can be placed perpendicular to each other. The balun feed structure is "Γ" shaped, and the structures near the two balun feed structures are connected by a semi-circular ring to reduce mutual interference between the baluns. The balun-fed structure adds a branch to the overall "Γ" shape. The polarization of the radiator in two directions is fed by two coaxial lines respectively. A pair of dipole units responsible for radiation in one polarization direction are printed on the upper and lower surfaces of the dielectric substrate respectively. In one polarization direction, the outer conductor of the coaxial line is connected to one of a pair of dipoles located on the lower surface of the dielectric substrate, and the other of the pair of dipoles located on the upper surface of the dielectric substrate extends a microstrip stub to the coaxial line position, and the inner conductor is connected to it. In another polarization direction, one of the dipoles on the lower surface of the dielectric substrate extends a microstrip stub to below the other of the dipoles on the upper surface of the dielectric substrate. The inner conductor of the coaxial line is connected to the dipole on the lower surface of the dielectric substrate, while the outer conductor is connected to the dipole on the upper surface of the dielectric substrate. The inner conductor is connected to the lower radiator of the dielectric substrate. The extension length of its stub does not completely cover the coaxial line. The remaining part of the outer conductor can bypass the stub and connect to the upper radiator of the dielectric substrate. In the sector dipole unit, the inner corners are all chamfered.

2. A base station antenna, characterized in that: The antenna includes the electromagnetically transparent dual-polarized base station antenna as described in claim 1 and a reflector, wherein the reflector is disposed behind the electromagnetically transparent dual-polarized base station antenna and is used for its directional radiation.

3. A tri-band base station antenna, characterized in that: The antenna includes the electromagnetic transparent dual-polarized base station antenna as described in claim 1, and another dual-band antenna is placed coaxially below the electromagnetic transparent antenna. The overall antenna structure can cover three frequency bands: 1.7-2.7GHz, 3.3-3.8GHz, and 4.8-5GHz. Each frequency band can radiate normally, and the interference between frequency bands is minimal.

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