Dual-band dual-polarization planar base station antenna

Abstract

This application provides a dual-band dual-polarized planar base station antenna, comprising a dielectric substrate and a metal layer. A differential feed network is provided on one side surface of the dielectric substrate. The differential feed network includes four differential input feed line branches, which are arranged in pairs and are centrally symmetrical with respect to the center of the dielectric substrate. Each differential input feed line branch has a first output feed line on one side and a second output feed line on the other side. The metal layer is disposed on the side of the dielectric substrate opposite to the differential feed network and has multiple first and second radiation slots with opposite opening directions arranged in pairs. The dielectric substrate has metallized vias penetrating both sides. Each first output feed line is connected to a second radiation slot through the metallized via. Each second output feed line is connected to a first radiation slot through the metallized via. The dual-band dual-polarized planar base station antenna provided by this application has a low profile and simple structure, making it more suitable for miniaturization requirements.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a dual-frequency dual-polarized planar base station antenna. Background Technology

[0002] With the rapid development of fifth-generation mobile communication technology (5G), the role of base station antennas in communication networks is becoming increasingly crucial. 5G networks typically need to simultaneously support dual-band coverage with operating center frequencies of 3.5GHz and 5GHz to meet communication needs in different scenarios: the 3.5GHz band is suitable for wide-area coverage, while the 5GHz band leverages wider spectrum resources to achieve high-speed data transmission, supporting the high-capacity demands of hotspot areas. On the other hand, dual-polarized antennas can improve spatial signal capacity through polarization multiplexing technology and mitigate multipath interference using polarization diversity, thereby enhancing the stability and anti-interference capabilities of communication links. Against this backdrop, base station antennas must possess dual-band dual-polarization characteristics to simultaneously support dual-polarized signal transmission across two frequency bands.

[0003] In related technologies, base station antennas typically employ multi-layer structures or complex three-dimensional components to achieve dual-frequency dual-polarization functionality, resulting in high antenna profiles and complex structures, making it difficult to meet the requirements of 5G base stations for antenna miniaturization, low profile, and low cost. Summary of the Invention

[0004] This application provides a dual-frequency dual-polarized planar base station antenna to solve the technical problems of current antennas having high profile, complex structure, and large size.

[0005] This application provides a dual-band dual-polarization planar base station antenna, which includes:

[0006] A dielectric substrate has a differential feed network on one side surface. The differential feed network includes four differential input feed branches, a first output feed line, and a second output feed line. The four differential input feed branches are arranged in pairs and are centrally symmetrical with respect to the center of the dielectric substrate. Each differential input feed branch has a first output feed line on one side and a second output feed line on the other side.

[0007] A metal layer is disposed on the side of the dielectric substrate opposite to the differential feed network; the metal layer is provided with a plurality of first radiation slots and second radiation slots in a U-shape; the first radiation slots and second radiation slots are arranged in pairs and have opposite opening directions.

[0008] The dielectric substrate has metallized vias extending through both sides; each first output feed line is connected to a second radiation slot through the metallized via; and each second output feed line is connected to a first radiation slot through the metallized via.

[0009] The dual-band dual-polarization planar base station antenna provided in this application has two sets of differential feed networks on one side of the dielectric substrate. Each set of differential feed networks includes two differential input feed branches. The four differential input feed branches realize efficient signal distribution and impedance matching. A metal layer is set on the other side of the dielectric substrate. The metal layer has a differentiated size design with back-to-back U-shaped radiation slots to realize independent coverage of dual bands. The radiation slots and feed networks are both distributed in a rotationally symmetrical manner with respect to the center of the ground plane to ensure the consistency of radiation characteristics in all directions. This achieves high-performance dual-band dual-polarization function. The structure is simple and has a low profile, making it more suitable for miniaturization requirements.

[0010] As an optional implementation, each differential input feed line includes a microstrip line and a main transmission line. One end of the microstrip line is flush with the edge of the dielectric substrate, and the main transmission line is connected to the end of the microstrip line away from the edge of the dielectric substrate. The main transmission line extends in the same direction as the microstrip line.

[0011] The first output feeder and the second output feeder are located on both sides of the main transmission line.

[0012] As an optional implementation, both the first output feeder and the second output feeder include a long arm segment and a short arm segment; the long arm segment and the short arm segment are connected to form an L-shaped broken line segment structure, and the length of the long arm segment is greater than the length of the short arm segment;

[0013] The long arm segment is set parallel to the main transmission line, and the short arm segment is connected to the end of the long arm segment away from the microstrip line. The short arm segment bends away from the main transmission line relative to the long arm segment.

[0014] This configuration, using long and short arm segments to form an L-shaped output feeder structure, achieves impedance matching with the differential input feeder branch, ensuring low signal loss transmission.

[0015] As an alternative implementation, the metallized via is connected to the short arm segment.

[0016] As an optional implementation, on both sides of the corresponding differential input feeder branch, the short arm segments of the first output feeder and the short arm segments of the second output feeder are arranged collinearly.

[0017] This configuration, by setting the two short arm segments on both sides of the differential input feeder branch to be collinear, helps to maintain the relative phase difference of the signals of the two short arm segments.

[0018] As an alternative implementation, the spacing between the long arm segment of the first output feed and the main transmission line on both sides of the corresponding differential input feed branch is different from the spacing between the long arm segment of the second output feed and the main transmission line.

[0019] This configuration allows the differential input feeder branch to have different coupling coefficients with the first and second output feeders, thus enabling more flexible impedance matching between the branch and the first and second radiation slots, respectively.

[0020] As an optional implementation, the dielectric substrate is square, and the four differential input feed lines are symmetrically distributed around the center of the dielectric substrate at a 90° rotation center; the signals of the two differential input feed line branches arranged in pairs have opposite phases and equal amplitudes.

[0021] This configuration, by symmetrically arranging the differential feed network along the center of the dielectric substrate, helps to ensure the uniformity of signal input.

[0022] As an optional implementation, there are four first radiation slots and four second radiation slots. The four first radiation slots form a radiation slot group, and the four second radiation slots form another radiation slot group. Both radiation slot groups are symmetrically distributed around the center of the dielectric substrate at a 90° rotation center.

[0023] This configuration, by symmetrically distributing the two radiation slot groups along the center of the dielectric substrate, helps to ensure the consistency of radiation characteristics in all directions, supports polarization multiplexing and diversity reception, and effectively improves system capacity and anti-interference capability.

[0024] As an optional implementation, both the first and second radiation slots are half-wavelength resonant structures corresponding to the center operating frequency.

[0025] This configuration helps to improve the radiation efficiency of the first and second radiation slits.

[0026] As an optional implementation, both the first and second radiating slots are parallel to the main transmission line of the corresponding differential input feeder branch, and the distance between the first and second radiating slots and the main transmission line is equal.

[0027] This setup can most effectively excite the half-wavelength resonance of the gap.

[0028] This application provides a dual-band dual-polarized planar base station antenna, comprising a dielectric substrate and a metal layer. A differential feed network is provided on one side surface of the dielectric substrate. The differential feed network includes four differential input feed branches, a first output feed line, and a second output feed line. The four differential input feed branches are arranged in pairs and are centrally symmetrical with respect to the center of the dielectric substrate. Each differential input feed branch has a first output feed line on one side and a second output feed line on the other side. The metal layer is disposed on the side of the dielectric substrate opposite to the differential feed network and has multiple U-shaped first and second radiating slots. The first and second radiating slots are arranged in pairs and have opposite opening directions. The dielectric substrate has metallized vias penetrating both sides. Each first output feed line is connected to a second radiating slot through a metallized via. Each second output feed line is connected to a first radiating slot through a metallized via. The dual-band dual-polarized planar base station antenna provided by this application has a low profile and simple structure, making it more suitable for miniaturization requirements.

[0029] In addition to the technical problems solved by the embodiments of this application, the technical features constituting the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions described above, other technical problems that can be solved by the dual-frequency dual-polarized planar base station antenna provided by this application, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features will be further explained in detail in the specific implementation. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the structure of a dual-band dual-polarization planar base station antenna provided in an embodiment of this application;

[0032] Figure 2 A schematic diagram of a differential input feeder branch provided in an embodiment of this application;

[0033] Figure 3 This is a schematic diagram of the structure of the metal layer provided in an embodiment of this application;

[0034] Figure 4 The S-parameter simulation diagram of the dual-frequency dual-polarization planar base station antenna provided in the embodiments of this application;

[0035] Figure 5 A simulation diagram of the gain curve of a dual-frequency dual-polarization planar base station antenna provided in an embodiment of this application;

[0036] Figure 6 A simulation diagram of the radiation direction of a dual-frequency dual-polarized planar base station antenna provided in an embodiment of this application.

[0037] Explanation of reference numerals in the attached figures:

[0038] 10- Dual-band dual-polarization planar base station antenna;

[0039] 100 - Dielectric substrate; 110 - Metallized via;

[0040] 200 - Differential feed network; 210 - Differential input feed branch; 211 - Microstrip line; 212 - Main transmission line; 213 - First differential input feed branch; 214 - Second differential input feed branch; 215 - Third differential input feed branch; 216 - Fourth differential input feed branch; 220 - First output feed; 221 - Long arm segment; 222 - Short arm segment; 230 - Second output feed;

[0041] 300 - Metal layer; 301 - First radiation slot pair; 302 - Second radiation slot pair; 303 - Third radiation slot pair; 304 - Fourth radiation slot pair; 310 - First radiation slot; 320 - Second radiation slot. Detailed Implementation

[0042] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0043] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0044] The terms "first," "second," and "third" (if any) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein.

[0045] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such as a process, method, system, product, or maintenance tool that includes a series of steps or units, not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or maintenance tool.

[0046] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] With the rapid development of fifth-generation mobile communication technology (5G), the role of base station antennas in communication networks is becoming increasingly crucial. 5G networks typically need to simultaneously support dual-band coverage with operating center frequencies of 3.5GHz and 5GHz to meet communication needs in different scenarios: the 3.5GHz band is suitable for wide-area coverage, while the 5GHz band leverages wider spectrum resources to achieve high-speed data transmission, supporting the high-capacity demands of hotspot areas. On the other hand, dual-polarized antennas can improve spatial signal capacity through polarization multiplexing technology and mitigate multipath interference using polarization diversity, thereby enhancing the stability and anti-interference capabilities of communication links. Against this backdrop, base station antennas must possess dual-band dual-polarization characteristics to simultaneously support dual-polarized signal transmission across two frequency bands.

[0048] In related technologies, base station antennas typically employ multi-layer structures or complex three-dimensional components to achieve dual-frequency dual-polarization functionality, resulting in high antenna profiles and complex structures, making it difficult to meet the requirements of 5G base stations for antenna miniaturization, low profile, and low cost.

[0049] To address the aforementioned technical issues, this application provides a dual-band dual-polarization planar base station antenna. Through the collaborative design of a differential feed network and symmetrical back-to-back U-shaped slots, the antenna achieves structural simplification and performance optimization. The core of this concept lies in utilizing a differential feed network to achieve efficient signal distribution and impedance matching, and in using the differentiated size design of the back-to-back U-shaped slots to achieve independent coverage of both frequency bands. Simultaneously, both the radiating slots and the feed network are rotationally symmetrically distributed around the center of the ground plane, ensuring consistent radiation characteristics in all directions, thereby achieving high-performance dual-band dual-polarization functionality in a low-profile structure. This concept overcomes the limitations of traditional multi-layer or three-dimensional structures, offering a low profile, simple structure, and better suitability for miniaturization requirements.

[0050] Reference Figures 1 to 6As shown, this application provides a dual-band dual-polarized planar base station antenna 10. The dual-band dual-polarized planar base station antenna 10 includes a dielectric substrate 100, a differential feed network 200, and a metal layer 300. The differential feed network 200 is disposed on one side of the dielectric substrate 100, and the metal layer 300 is disposed on the other side of the dielectric substrate 100. The metal layer 300 has a radiation slot. The differential feed network 200 is connected to the radiation slot to transmit or receive signals.

[0051] In this embodiment of the application, the differential feed network 200 includes four differential input feed branches 210, a first output feed 220, and a second output feed 230; the four differential input feed branches 210 are arranged in pairs and are centrally symmetrical with respect to the center of the dielectric substrate 100; each differential input feed branch 210 has a first output feed 220 on one side and a second output feed 230 on the other side.

[0052] It should be noted that the differential input feed branch 210 can stably distribute the signal to the first output feed 220 and the second output feed 230 on both sides through electromagnetic coupling, and then the first output feed 220 and the second output feed 230 transmit the signal to the metal layer 300.

[0053] In this embodiment, the metal layer 300 is provided with four first radiation slots 310 and four second radiation slots 320 in a U-shape; the first radiation slots 310 and the second radiation slots 320 are arranged in pairs and have opposite opening directions, the opening of the first radiation slots 310 faces the edge of the dielectric substrate 100, and the second radiation slots 320 face the center of the dielectric substrate 100, and the paired first radiation slots 310 and second radiation slots 320 form a back-to-back structure.

[0054] The dielectric substrate 100 has metallized vias 110 extending through both sides. Each first output feed line 220 is connected to a second radiation slot 320 through the metallized via 110, and the first output feed line 220 and the second radiation slot 320 are impedance matched. Each second output feed line 230 is connected to a first radiation slot 310 through the metallized via 110, and the second output feed line 230 and the first radiation slot 310 are impedance matched. When a signal is input through the differential input feed line branch 210, the signal is transmitted to the corresponding second radiation slot 320 or first radiation slot 310 via the first output feed line 220 and the second output feed line 230, ensuring low-loss signal transmission. The signal is also induced by the U-shaped slot on the metal layer 300 through the metallized via 110, ultimately forming radiation.

[0055] Understandably, the differential feed network 200 and the back-to-back radiation slot structure are integrated on the upper and lower surfaces of a single dielectric substrate 100, and adopt a centrally symmetrical layout. The cross-sectional height is the same as the thickness of the dielectric substrate 100. The planar design reduces the antenna cross-section, making it more suitable for miniaturization requirements. The symmetrical design of the differential feed network 200 ensures the uniformity of signal distribution and avoids radiation pattern deviation caused by structural asymmetry. The back-to-back radiation slots on the metal layer 300, through their opposite opening directions, form a complementary distribution of electromagnetic fields, effectively suppressing electromagnetic interference between dual-polarized channels.

[0056] In this embodiment, the differential input feed branch 210 includes a microstrip line 211 and a main transmission line 212. The microstrip line 211 is flush with the edge of the dielectric substrate 100, and the main transmission line 212 is connected to the end of the microstrip line 211 away from the edge of the dielectric substrate 100. The main transmission line 212 extends in the same direction as the microstrip line 211. The first output feed line 220 and the second output feed line 230 are disposed on both sides of the main transmission line 212.

[0057] Understandably, one end of the microstrip line 211 is flush with the edge of the dielectric substrate 100. This end of the microstrip line 211 forms an input port for connecting to an external signal source and transmitting the signal to the main transmission line 212. The main transmission line 212 is connected to the end of the microstrip line 211 and distributes the signal to the first output feed line 220 and the second output feed line 230 on both sides. The first output feed line 220 and the second output feed line 230 serve as output ports for exciting the first radiation slot 310 and the second radiation slot 320.

[0058] The width of microstrip line 211 is greater than that of main transmission line 212, resulting in a lower impedance for microstrip line 211 than for main transmission line 212. The larger width of microstrip line 211 allows for impedance matching with external standard transmission systems, preventing energy reflection at the interface. The smaller width of main transmission line 212 allows for impedance matching with the first output feed line 220 and the second output feed line 230, thereby efficiently coupling energy to both output feed lines 220 and 230.

[0059] As one possible implementation, both the first output feed line 220 and the second output feed line 230 include a long arm segment 221 and a short arm segment 222; the long arm segment 221 and the short arm segment 222 are connected in an L-shaped broken line structure, and the length of the long arm segment 221 is greater than the length of the short arm segment 222; wherein, the long arm segment 221 is set parallel to the main transmission line 212, the short arm segment 222 is connected to the end of the long arm segment 221 away from the microstrip line 211, and the short arm segment 222 bends away from the main transmission line 212 relative to the long arm segment 221.

[0060] Understandably, the long arm segments 221 of the first output feed line 220 and the second output feed line 230 are parallel to the main transmission line 212, forming a coupling region for energy transfer from the main transmission line 212 to the output feed lines. The long arm segments 221 are relatively long, ensuring the strength and quality of the coupling effect, so that energy can be efficiently coupled from the main transmission line 212 to the long arm segments 221 of the two output feed lines. At the same time, the long arm segments 221 must also be long enough to establish a coupling mechanism that generates the required phase relationship within the required operating frequency band. The end of the short arm segment 222 facing away from the main transmission line 212 is connected to the metallized via 110. The short arm segment 222 is used for direction turning and signal transmission. Its electrical length is usually designed to be much smaller than the operating wavelength to ensure that its impact on the phase is small and predictable.

[0061] In this embodiment, the long arm segment 221 and the short arm segment 222 are perpendicular to each other. By adjusting the length and width of the long arm segment 221 and the short arm segment 222, the impedance matching balance of the signals in the low frequency band and the high frequency band can be adjusted. The length ratio of the long arm segment 221 and the short arm segment 222 is not specifically limited in this embodiment.

[0062] As one possible implementation, on both sides of the corresponding differential input feed branch 210, the short arm segment 222 of the first output feed 220 and the short arm segment 222 of the second output feed 230 are arranged collinearly.

[0063] It is understandable that, since the short arm segments 222 of the first output feed line 220 and the short arm segments 222 of the second output feed line 230 are of equal length and collinearly arranged, the physical path length of each short arm segment 222 from the L-shaped connection inflection point to the connection point of the metallized via 110 is equal. Thus, the total physical path length of the signal from the equivalent coupling start point on the main transmission line 212 to the output point of the short arm segments 222 on both sides is absolutely equal for the two output channels, thereby ensuring that the physical transmission path will not cause a difference in the phase of the first output feed line 220 and the second output feed line 230.

[0064] In this embodiment, the long arm segment 221 of the first output feed line 220 and the long arm segment 221 of the second output feed line 230 are of equal length. Thus, the structures of the first output feed line 220 and the second output feed line 230 are completely identical, ensuring that the signal paths of the first output feed line 220 and the second output feed line 230 are exactly the same, thereby ensuring that the phase difference between the signals of the first output feed line 220 and the second output feed line 230 is always the same.

[0065] As one possible implementation, the spacing between the long arm segment 221 of the first output feed line 220 and the main transmission line 212 on both sides of the corresponding differential input feed line branch 210 is different from the spacing between the long arm segment 221 of the second output feed line 230 and the main transmission line 212.

[0066] It is understandable that the signal transmission paths of the first output feed line 220 and the second output feed line 230 will not cause a difference in signal phase. However, since the spacing between the long arm segment 221 of the first output feed line 220 and the main transmission line 212 is different from that of the long arm segment 221 of the second output feed line 230 and the main transmission line 212, the coupling strength between the main transmission line 212 and the first output feed line 220 and the second output feed line 230 is different. Therefore, the signal amplitude coupled to the long arm segment 221 of the first output feed line 220 and the signal amplitude coupled to the long arm segment 221 of the second output feed line 230 can be achieved by different coupling strengths.

[0067] In this embodiment, the long arm segment 221 of the first output feed line 220 has the same width as the long arm segment 221 of the second output feed line 230. This reduces the variables in the power supply network structure parameters, lowers the structural complexity, and thus improves design efficiency. (Refer to...) Figure 2 The distance between the long arm segment 221 of the first output feed line 220 and the main transmission line 212 is g1, and the distance between the long arm segment 221 of the second output feed line 230 and the main transmission line 212 is g2, where g1 is greater than g2. This ensures that the coupling strength between the main transmission line 212 and the first output feed line 220 is less than the coupling strength between the main transmission line 212 and the second output feed line 230. By adjusting g1 and g2, the impedance matching between the main transmission line 212 and the first output feed line 220 and the second output feed line 230 can be flexibly adjusted, ensuring low-loss signal transmission. The signals from the first output feed line 220 and the second output feed line 230 are transmitted from the long arm segment 221 to the short arm segment 222, and finally through the metallized via 110 to the corresponding radiating slot, thus radiating the signal outwards.

[0068] In this embodiment, the dielectric substrate 100 is square and made of Rogers 5880 material with a dielectric constant of 2.2. It has a length and width of 120 mm and a thickness of 2 mm. Four differential input feed branches 210 are formed, and the differential feed network 200 is symmetrically distributed around the center of the dielectric substrate 100 at a 90° rotational center, ensuring signal input uniformity. Two pairs of differential input feed branches 210 are symmetrically arranged with respect to the center point of the dielectric substrate 100. The signals of the two pairs of differential input feed branches 210 have opposite phases and equal amplitudes, forming a differential feed structure. The four differential input feed branches 210 form two pairs of differential feed structures, allowing the antenna's radiated signal to form two polarization directions in space.

[0069] There are four first radiation slots 310 and four second radiation slots 320. The four first radiation slots 310 form a radiation slot group, and the four second radiation slots 320 form another radiation slot group. Both radiation slot groups are symmetrically distributed around the center of the dielectric substrate 100 at a 90° rotation center.

[0070] It is understandable that the differential feed network 200 and the radiating slots are both distributed in a rotationally symmetrical manner around the center of the dielectric substrate 100, which not only ensures the consistency of radiation characteristics in all directions, but also supports polarization multiplexing and diversity reception, effectively improving system capacity and anti-interference capability.

[0071] In this embodiment, four first radiating slots 310 and two radiating slots 320 form four pairs of radiating slots, including a first radiating slot pair 301, a second radiating slot pair 302, a third radiating slot pair 303, and a fourth radiating slot pair 304. The differential input feeder branch 210 includes a first differential input feeder branch 213, a second differential input feeder branch 214, a third differential input feeder branch 215, and a fourth differential input feeder branch 216. The first differential input feeder branch 213 mates with the first radiating slot pair 301, the second differential input feeder branch 214 mates with the second radiating slot pair 302, the third differential input feeder branch 215 mates with the third radiating slot pair 303, and the fourth differential input feeder branch 216 mates with the fourth radiating slot pair 304. The first differential input feed branch 213 and the third differential input feed branch 215 are paired to form a differential feed structure, and the second differential input feed branch 214 and the fourth differential input feed branch 216 are paired to form another differential feed structure. The first radiating slot pair 301 and the third radiating slot pair 303 form one polarization channel with the polarization direction X in the figure, and the second radiating slot pair 302 and the fourth radiating slot pair 304 form another polarization channel with the polarization direction Y in the figure. The signal radiation directions of the two polarization channels are perpendicular to each other, forming a dual-frequency, dual-polarized antenna.

[0072] For example, when it is necessary to activate the polarization channel formed by the first radiation slot pair 301 and the third radiation slot pair 303, the external differential signal is respectively connected to the microstrip line 211 of the first differential input feed branch 213 and the microstrip line 211 of the third differential input feed branch 215, and then enters the two main transmission lines 212. The two main transmission lines 212 electromagnetically couple the signal to the two first output feed lines 220 and the two second output feed lines 230 on their respective sides. The two first output feed lines 220 pass through the dielectric substrate 100 through the corresponding two metallized vias, respectively stimulating the second radiation slot 320 of the first radiation slot pair 301 and the second radiation slot 320 of the third radiation slot pair 303, generating induced current. The two second output feed lines 230 pass through the dielectric substrate 100 through the corresponding two metallized vias, respectively stimulating the first radiation slot 310 of the first radiation slot pair 301 and the first radiation slot 310 of the third radiation slot pair 303, generating induced current, and finally forming radiation. The radiation mode of the polarization channel formed by the second radiation slot pair 302 and the fourth radiation slot pair 304 is the same as the radiation mode described above.

[0073] As one possible implementation, both the first radiation slot 310 and the second radiation slot 320 are half-wavelength resonant structures corresponding to the center operating frequency.

[0074] Understandably, the effective electrical length of the first radiating slot 310 and the second radiating slot 320 is approximately equal to half the wavelength of the antenna's operating center frequency. When the slot length is half a wavelength, the slot can be considered an efficient magnetic current source, achieving peak efficiency in radiating electromagnetic waves into free space. Simultaneously, near the half-wavelength resonant point, the slot's input impedance exhibits relatively pure resistivity, and its resistance can be adjusted through the slot width, dielectric substrate 100 parameters, etc., facilitating good matching with the differential feed network 200 and ensuring efficient energy transmission.

[0075] It should be noted that the dimensions of the first radiation slot 310 and the second radiation slot 320 are different. By adjusting the length and width of the first radiation slot 310 and the second radiation slot 320, independent dual-band coverage can be achieved.

[0076] As one possible implementation, the first radiating slot 310 and the second radiating slot 320 are both parallel to the main transmission line 212 of the corresponding differential input feed branch 210, and the distance between the first radiating slot 310 and the second radiating slot 320 and the main transmission line 212 is equal.

[0077] Understandably, the geometric alignment of the first radiating slot 310 and the second radiating slot 320 ensures that the differential signal of the main transmission line 212 can be precisely fed into the optimal positions at both ends of the first radiating slot 310 and the second radiating slot 320 through the metallized via 110, thereby most effectively exciting the half-wavelength resonance of the slot.

[0078] Figure 4 and Figure 5 The diagram shows the antenna's S-parameters and gain as a function of frequency. It can be observed that the center frequencies of the two operating frequency bands of the dual-band dual-polarization planar base station antenna 10 are 3.55 GHz and 4.96 GHz, respectively, with -10 dB bandwidths of 4.6% and 11.8% (3.47-3.63 GHz, 4.51-5.09 GHz), respectively. The low-frequency band has one in-band radiation pole, while the high-frequency band has two. The isolation between the two polarization channels is greater than 55 dB. The maximum gains within the two operating frequency bands are 10.4 dBi and 9.0 dBi, respectively.

[0079] Figure 6 The diagram shows the radiation patterns within the two passbands of the polarization channel formed by the first radiation slot pair 301 and the third radiation slot pair 303. It can be seen that the maximum radiation direction of the antenna remains consistent within both passbands, and the antenna's cross-polarization level is below -25 dB. Furthermore, the radiation patterns of the two polarization channels are completely identical.

[0080] The dual-band dual-polarized planar base station antenna 10 of this application can achieve high performance and similar radiation beams in two frequency bands based on a simple structure, which is beneficial to improving the signal coverage problem of wireless communication systems. At the same time, it has the advantages of low profile, light weight, simple processing and low price.

[0081] This application provides a dual-band dual-polarized planar base station antenna 10, including a dielectric substrate 100 and a metal layer 300. A differential feed network 200 is provided on one side surface of the dielectric substrate 100. The differential feed network 200 includes four differential input feed line branches 210, which are arranged in pairs and are centrally symmetrical with respect to the center of the dielectric substrate 100. Each differential input feed line branch 210 has a first output feed line 220 on one side and a second output feed line 230 on the other side. The metal layer 300 is provided with... The antenna is positioned on the side of the dielectric substrate 100 opposite to the differential feed network 200 and has a plurality of U-shaped first radiating slots 310 and second radiating slots 320. The first radiating slots 310 and second radiating slots 320 are arranged in pairs with opposite opening directions. The dielectric substrate 100 has metallized vias 110 extending through both sides. Each first output feed line 220 is connected to a second radiating slot 320 through the metallized via 110. Each second output feed line 230 is connected to a first radiating slot 310 through the metallized via 110. The dual-band dual-polarized planar base station antenna 10 provided in this application has a low profile and simple structure, making it more suitable for miniaturization requirements.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A dual-frequency, dual-polarization planar base station antenna, characterized in that, include: A dielectric substrate (100) has a differential feed network (200) on one side surface. The differential feed network (200) includes four differential input feed branches (210), a first output feed (220), and a second output feed (230). The four differential input feed branches (210) are arranged in pairs and are centrally symmetrical with respect to the center of the dielectric substrate (100). Each differential input feed branch (210) has a first output feed (220) on one side and a second output feed (230) on the other side. A metal layer (300) is disposed on the side of the dielectric substrate (100) facing away from the differential feed network (200); the metal layer (300) is provided with a plurality of U-shaped first radiation slots (310) and second radiation slots (320); the first radiation slots (310) and the second radiation slots (320) are arranged in pairs and have opposite opening directions; the first radiation slots (310) and the second radiation slots (320) have different sizes, and by adjusting the length and slot width of the first radiation slots (310) and the second radiation slots (320), dual-band independent coverage can be achieved; The dielectric substrate (100) is provided with metallized vias (110) extending through both sides therethrough; each of the first output feed lines (220) is connected to a second radiation slot (320) through the metallized vias (110); each of the second output feed lines (230) is connected to a first radiation slot (310) through the metallized vias (110); The dielectric substrate (100) is square, and the four differential input feed branches (210) are symmetrically distributed at a 90° rotation center relative to the center of the dielectric substrate (100); the signals of the two differential input feed branches (210) arranged in pairs have opposite phases and equal amplitudes; The first radiation slot (310) and the second radiation slot (320) are both half-wavelength resonant structures corresponding to the center operating frequencies of the two frequency bands.

2. The dual-frequency dual-polarization planar base station antenna according to claim 1, characterized in that, Each of the differential input feed branch (210) includes a microstrip line (211) and a main transmission line (212). The microstrip line (211) is flush with the edge of the dielectric substrate (100), and the main transmission line (212) is connected to the end of the microstrip line (211) away from the edge of the dielectric substrate (100). The main transmission line (212) extends in the same direction as the microstrip line (211). The first output feed (220) and the second output feed (230) are disposed on both sides of the main transmission line (212).

3. The dual-frequency dual-polarization planar base station antenna according to claim 2, characterized in that, Both the first output feed line (220) and the second output feed line (230) include a long arm segment (221) and a short arm segment (222); the long arm segment (221) and the short arm segment (222) are connected to form an L-shaped broken line structure, and the length of the long arm segment (221) is greater than the length of the short arm segment (222); The long arm segment (221) is arranged parallel to the main transmission line (212), the short arm segment (222) is connected to the end of the long arm segment (221) away from the microstrip line (211), and the short arm segment (222) is bent away from the main transmission line (212) relative to the long arm segment (221).

4. The dual-frequency dual-polarization planar base station antenna according to claim 3, characterized in that, The metallized through hole (110) is connected to the short arm segment (222).

5. The dual-frequency dual-polarization planar base station antenna according to claim 3, characterized in that, On both sides of the corresponding differential input feed branch (210), the short arm segment (222) of the first output feed (220) and the short arm segment (222) of the second output feed (230) are collinear.

6. The dual-frequency dual-polarization planar base station antenna according to claim 3, characterized in that, On both sides of the corresponding differential input feed branch (210), the spacing between the long arm segment (221) of the first output feed (220) and the main transmission line (212) is different from the spacing between the long arm segment (221) of the second output feed (230) and the main transmission line (212).

7. The dual-frequency dual-polarization planar base station antenna according to any one of claims 1-6, characterized in that, There are four of each of the first radiation slots (310) and the second radiation slots (320). The four first radiation slots (310) form a radiation slot group, and the four second radiation slots (320) form another radiation slot group. Both radiation slot groups are symmetrically distributed around the center of the dielectric substrate (100) at a 90° rotation center.

8. The dual-frequency dual-polarization planar base station antenna according to any one of claims 2-6, characterized in that, The first radiating slot (310) and the second radiating slot (320) are both parallel to the main transmission line (212) of the corresponding differential input feed branch (210), and the first radiating slot (310) and the second radiating slot (320) are equally spaced from the main transmission line (212).

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