Differential feed network and antenna

Abstract

The invention provides a differential feed network for a dual polarized antenna and an antenna. The differential feed network comprises a first feed line and a second feed line which intersect with each other, and the first feed line and the second feed line intersect at a central point. The first feed line comprises a first feed output port and a second feed output port which are respectively arranged at two end points of the first feed line, and the second feed line comprises a third feed output port and a fourth feed output port which are respectively arranged at two end points of the second feed line. The differential feed network also includes a first input feed line and a second input feed line. One end of the first input feeder line is provided with a first feed input port, and the other end of the first input feeder line is electrically connected to the first feeder line. One end of the second input feeder line is provided with a second feed input port, and the other end of the second input feeder line is electrically connected to the second feeder line. The first feed line and the second feed line are electrically connected to each other at a center point.

Description

Technical Field

[0001] The present disclosure relates to the field of communication technology, and in particular to a differential feeding network and an antenna. Background Art

[0002] With the rapid development of mobile communication technology, the operating frequency of base station antennas is constantly increasing, and the degree of integration is gradually increasing. Therefore, the antenna needs to have high radiation efficiency, low cross polarization, and symmetrical pattern. In addition, due to the gradual depletion of space resources for setting up antennas, compact small-pitch antenna arrays and multi-frequency co-aperture antenna arrays can obtain stronger signal transmission capabilities within a limited antenna aperture, and therefore have received widespread attention. However, these application environments place higher requirements on the miniaturization of antenna units and feed networks.

[0003] Therefore, providing a compact differential feeding network is the key to achieving high performance base station antennas. Summary of the invention

[0004] The present disclosure provides a differential feeding network and an antenna.

[0005] In a first aspect, an embodiment of the present disclosure provides a differential feeding network for a dual-polarized antenna, comprising: a first feeder and a second feeder intersecting each other, wherein the first feeder intersects with the second feeder at a center point, the first feeder comprises a first feed output port and a second feed output port respectively arranged at two end points of the first feeder, the second feeder comprises a third feed output port and a fourth feed output port respectively arranged at two end points of the second feeder, the differential feeding network further comprises a first input feeder and a second input feeder, one end of the first input feeder is provided with a first feed input port, the other end of the first input feeder is electrically connected to the first feeder, one end of the second input feeder is provided with a second feed input port, the other end of the second input feeder is electrically connected to the second feeder, wherein the first feeder and the second feeder are electrically connected to each other at the center point.

[0006] In a second aspect, an embodiment of the present disclosure provides a matrix differential feeding network, comprising a plurality of unit differential feeding networks arranged in a matrix, wherein the unit differential feeding network comprises a differential feeding network according to an embodiment of the present disclosure, wherein the first input feed lines of at least two unit differential feeding networks located in the same column are electrically connected to each other and the second input feed lines are electrically connected to each other, and the at least two unit differential feeding networks are fed via the same first feeding input port and the same second feeding input port.

[0007] In a third aspect, an embodiment of the present disclosure provides an antenna, comprising a metal radiation patch, a differential feeding network and a metal reflector, wherein the differential feeding network comprises a differential feeding network according to an embodiment of the present disclosure, the metal radiation patch is placed above the differential feeding network, and the differential feeding network is placed above the metal reflector, and the antenna also includes a connecting structure arranged between the metal radiation patch and the differential feeding network.

[0008] The differential feeding network according to the embodiment of the present disclosure is a miniaturized differential feeding network. By arranging the first feed line and the second feed line to be electrically connected to each other at a center point, the wiring area of ​​the differential feeding network can be reduced, and the differential feeding network can have a symmetrical structure to avoid the problem of asymmetry in the antenna radiation pattern. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In the accompanying drawings of the embodiments of the present disclosure:

[0010] Figure 1 An example of a dual-polarized antenna and a differential feeding network in the related art is shown;

[0011] Figure 2 A top view of a differential feeding network for a dual-polarized antenna according to an embodiment of the present disclosure is shown;

[0012] Figure 3 A schematic diagram of current when a differential feeding network excites an antenna according to an embodiment of the present disclosure is shown;

[0013] Figure 4 An equivalent circuit diagram of an antenna using a differential feeding network according to an embodiment of the present disclosure is shown;

[0014] Figure 5 shows circuit simulation results of an antenna using a differential feed network according to an embodiment of the present disclosure;

[0015] Figure 6 Another top view of a differential feed network according to an embodiment of the present disclosure is shown;

[0016] Figure 7 Another top view of a differential feed network according to an embodiment of the present disclosure is shown;

[0017] Figure 8 Another top view of a differential feed network according to an embodiment of the present disclosure is shown;

[0018] Fig. 9 A schematic diagram of the structure of an antenna according to an embodiment of the present disclosure is shown;

[0019] Fig.10 Shows Fig. 9 The connection structure in the antenna shown;

[0020] Fig.11 Shows Fig. 9 The surface electric field distribution of the differential feed network of the antenna shown;

[0021] Fig.12 Shows Fig. 9 The S-parameter diagram of the antenna shown;

[0022] Fig.13 Shows Fig. 9 The radiation pattern of the antenna shown;

[0023] Fig.14 Another example of a differential feed network according to an embodiment of the present disclosure is shown;

[0024] Fig.15 A schematic diagram of the structure of an antenna according to an embodiment of the present disclosure is shown;

[0025] Fig.16 Shows Fig.15 The surface electric field distribution of the metal radiation patch and differential feed network of the antenna shown;

[0026] Fig.17 Shows Fig.15 The S-parameter diagram of the antenna shown;

[0027] Fig.18 Shows Fig.15 The radiation pattern of the antenna shown;

[0028] Fig.19 Various modified examples of antennas according to embodiments of the present disclosure are shown;

[0029] Fig. 20 shows a modified example of the antenna according to an embodiment of the present disclosure;

[0030] Fig.21 An example of a matrix differential feed network according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the technical solution of the present disclosure, the embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0032] The present disclosure will be described more fully below with reference to the accompanying drawings, but the embodiments shown may be embodied in different forms, and the present disclosure should not be construed as being limited to the embodiments set forth below. On the contrary, the purpose of providing these embodiments is to make the present disclosure thorough and complete, and to enable those skilled in the art to fully understand the scope of the present disclosure.

[0033] The accompanying drawings of the embodiments of the present disclosure are used to provide a further understanding of the embodiments of the present disclosure, and constitute a part of the specification, and are used together with the detailed embodiments to explain the present disclosure, and do not constitute a limitation of the present disclosure. By describing the detailed embodiments with reference to the accompanying drawings, the above and other features and advantages will become more apparent to those skilled in the art.

[0034] The present disclosure may be described with reference to plan views and / or cross-sectional views by means of ideal schematic views of the present disclosure. Therefore, the exemplary illustrations may be modified according to manufacturing techniques and / or tolerances.

[0035] In the absence of conflict, the various embodiments of the present disclosure and the various features therein may be combined with each other.

[0036] The terms used in the present disclosure are only used to describe specific embodiments and are not intended to limit the present disclosure. The term "and / or" as used in the present disclosure includes any and all combinations of one or more related enumerated items. The singular forms "one" and "the" as used in the present disclosure are also intended to include plural forms, unless the context clearly indicates otherwise. The terms "including", "made of..." as used in the present disclosure specify the presence of the features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or groups thereof.

[0037] Unless otherwise defined, all terms (including technical and scientific terms) used in this disclosure have the same meaning as commonly understood by those of ordinary skill in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and this disclosure, and will not be interpreted as having an idealized or overly formal meaning unless expressly defined in this disclosure.

[0038] The present disclosure is not limited to the embodiments shown in the drawings, but includes modifications of the configurations formed based on the manufacturing process. Therefore, the regions illustrated in the drawings have schematic properties, and the shapes of the regions shown in the drawings illustrate the specific shapes of the regions, but are not intended to be limiting.

[0039] Common base station antenna unit forms include microstrip antennas and dipole antennas. In order to ensure the working bandwidth, the antenna usually needs to have a certain profile height, but this will cause the antenna pattern to shift and worsen the cross-polarization. In some designs, cross-polarization is suppressed by opening slots or loading parasitic mechanisms at specific locations of the antenna, but this will make the antenna structure complicated.

[0040] In order to solve these problems, differential feeding has become the mainstream design solution in current base station antenna design. In the related art, in order to avoid the overlap and short circuit of the two polarization lines of the differential feeding network, a large wiring area is required, which cannot adapt to the miniaturization trend of array antennas. In addition, for microstrip antennas with low profile heights, the asymmetric routing form of the differential feeding network in the related art can easily produce asymmetric coupling with the radiation structure, resulting in asymmetric antenna patterns and deterioration of standing waves, gain and other performance.

[0041] Figure 1 An example of a dual-polarization antenna and a differential feeding network in the related art is shown. Figure 1 The left side of FIG. shows a perspective view of a dual-polarized antenna including a metal radiation patch and a differential feed network. Figure 1 The right side of FIG shows a top view of the differential feed network.

[0042] like Figure 1 As shown, to achieve symmetrical radiation patterns and low cross-polarization, dual-polarized antennas usually use differential feeding structures. The antenna has four feed output ports, and each polarization is excited by two feed output ports with equal amplitudes and a phase difference of 180 degrees. In order to interconnect with the feed network of the antenna array, two 1-to-2 power dividers are required to form a differential feeding network to reduce the number of feed input ports for each polarization to one.

[0043] like Figure 1 As shown, ports P1 and P2 of the differential feeding network are respectively used for the two polarization feeding input ports of the dual-polarized antenna, and the differential feeding network feeds the metal radiation patch via four feeding output ports P3, P4, P5 and P6. Feeding output ports P3 and P6 are a pair of differential pairs, and feeding output ports P4 and P5 are a pair of differential pairs. When port P1 is fed, the current flows to feeding output ports P3 and P6 along path a and path b (shown as dotted lines in the figure) respectively. The phase difference between feeding output ports P3 and P6 is determined by the length difference between path a and path b. In order to ensure a symmetrical directional pattern, the phase difference is usually set to 180 degrees. Similarly, when port P2 is fed, feeding output ports P4 and P5 are excited, with equal amplitudes and a phase difference of 180 degrees. By using a differential feeding network, high isolation can be maintained between port P1 and port P2.

[0044] pass Figure 1It can be seen from the example that in the differential feeding network of the related art, in order to ensure the isolation between the feeding input ports P1 and P2 for the two polarizations, a separate 1-to-2 power divider is used for each polarization. At the same time, in order to reduce the coupling between the transmission lines, a certain distance needs to be maintained between the two power dividers. The above settings will cause the entire differential feeding network to occupy a large wiring area, which not only restricts the miniaturization of the antenna array, but also causes additional insertion loss, resulting in reduced antenna efficiency. On the other hand, Figure 1 The differential feeding network shown will also cause an asymmetric problem in the antenna radiation pattern due to its own asymmetric structure.

[0045] The embodiments of the present disclosure provide a compact differential feeding network.

[0046] Figure 2 A top view of a differential feeding network for a dual-polarized antenna according to an embodiment of the present disclosure is shown.

[0047] like Figure 2 As shown, the differential feeding network for the dual-polarized antenna according to the embodiment of the present disclosure includes a first feed line FL1 and a second feed line FL2 intersecting each other, and the first feed line FL1 and the second feed line FL2 intersect at a center point O. The first feed line FL1 includes a first feed output port P3 and a second feed output port P6 respectively arranged at two end points of the first feed line FL1, and the second feed line FL2 includes a third feed output port P4 and a fourth feed output port P5 respectively arranged at two end points of the second feed line FL2. Figure 1 As shown, the differential feeding network for the dual-polarized antenna according to the embodiment of the present disclosure further includes a first input feeder IFL1 and a second input feeder IFL2. A first feed input port P1 is provided at one end of the first input feeder IFL1, and the other end of the first input feeder IFL1 is electrically connected to the first feeder FL1. A second feed input port P2 is provided at one end of the second input feeder IFL2, and the other end of the second input feeder IFL2 is electrically connected to the second feeder FL2. The first feeder FL1 and the second feeder FL2 are electrically connected to each other at a center point O.

[0048] The differential feeding network according to the embodiment of the present disclosure may be integrally formed of metal material.

[0049] Figure 3 A schematic diagram of current when a differential feeding network excites an antenna according to an embodiment of the present disclosure is shown.

[0050] like Figure 3As shown, when the first feed input port P1 is fed, the current (shown as a dotted line in the figure) flows through the first feed output port P3 and the second feed output port P6. The phase difference between the first feed output port P3 and the second feed output port P6 is the line length L from the center point O to each feed output port. f Determine the line width W f The power ratio of the two feed output ports can be controlled. When the differential feed network according to the embodiment of the present disclosure is used to excite the antenna unit, each feed output port P3, P4, P5 and P6 is connected to the four feed positions corresponding to the antenna, and the impedance from each feed output port to the antenna is the same and matches the impedance of the antenna.

[0051] The technical principle of the present disclosure is described below.

[0052] First, it is explained why high isolation can be maintained between the feeding input ports P1 and P2 in the case where the first feed line FL1 and the second feed line FL2 intersect and are electrically connected.

[0053] When the feed input port P1 is excited, the corresponding polarized antenna mode (for example, +45 degree polarization mode) is excited, and the current flows as follows: Figure 3 As shown in the figure, the dotted line represents the current path when the feed input port P1 is excited, and the arrow indicates the direction of the current. f , so that the phase difference θ between the center point O and each feeding output port lf =90°, the phase difference between the first feed output port P3 and the second feed output port P6 is 180°. In this case, the +45 degree polarization mode of the antenna is excited, while the -45 degree polarization mode of the antenna is an orthogonal mode, which is related to the excitation of the feed input port P2.

[0054] The impedance Z from the third feed output port P4 and the fourth feed output port P5 to the antenna 4a and Z 5a is infinite, that is: Z 4a =Z 5a =∞

[0055] The impedance Z from the first feeding output port P3 to the third feeding output port P4 and the fourth feeding output port P5 34 and Z 35 It can be calculated by the following formula: Where Z0 is the characteristic impedance of the feeder.

[0056] Therefore, the current at the feed input port P1 will flow along the path shown in the figure (i.e., the line of the first feed line FL1) to excite the +45 degree polarization mode of the antenna, but will not flow along the center point O to the orthogonal line (i.e., the line of the second feed line FL2), thereby not affecting the isolation between the antenna feed input ports P1 and P2, nor affecting the cross-polarization performance of the radiation pattern.

[0057] Next, the reason why a short-circuit point to the ground can be provided at the center point O is explained.

[0058] The impedance Z from the center point O to the third feed output port P4 and the fourth feed output port P5 O4 and Z O5 It can be calculated by the following formula:

[0059] Therefore, relative to the +45 degree polarization, the -45 degree polarization orthogonal thereto can be equivalent to a short-circuit structure at a center point O. Therefore, a short-circuit point to the ground can be set at the center point O without affecting the performance of the antenna.

[0060] Compared with the differential feeding network of the related art, the differential feeding network according to the embodiment of the present disclosure can effectively reduce the line length of the feeding network, thereby reducing the loss of the feeding network. When the differential feeding network according to the embodiment of the present disclosure is applied to a small-pitch antenna array, it can have the advantages of symmetry and miniaturization. The symmetrical feeding structure can produce symmetrical near-field coupling with the antenna radiation structure, so as not to affect the symmetry of the antenna pattern. In addition, the miniaturized differential feeding network can reserve a larger area for the feeding network of the subarray, avoiding line crosstalk caused by too small line spacing, thereby avoiding affecting the transmission performance. The differential feeding network according to the embodiment of the present disclosure can be used as a differential feeding network for a dual-polarized antenna, and can solve the problem of performance deterioration of the differential feeding antenna and the problem of a large wiring area of ​​the differential feeding network.

[0061] Figure 4 An equivalent circuit diagram of an antenna using a differential feeding network according to an embodiment of the present disclosure is shown.

[0062] like Figure 4 As shown, each feed output port is connected to the metal radiation patch of the antenna, which can be equivalent to a parallel RLC (PRLC) load. The coupling between each feed output port can be equivalent to a parallel LC circuit. TL1 to TL4 are differential feed networks connected in the center. Feed input ports P1 and P2 feed the antenna unit through transmission lines TL5 and TL6, respectively, and correspond to two different polarization modes. The reflection coefficient and isolation of the antenna can be adjusted according to actual requirements. Figure 5The circuit simulation results of the antenna using the differential feeding network according to the embodiment of the present disclosure are shown, wherein the S(1, 1) curve shows the change of the reflection coefficient with the frequency, and the S(1, 2) curve shows the change of the isolation with the frequency. Figure 5 As shown, the antenna resonates at 4.9 GHz and the isolation of the ports is greater than 33 dB.

[0063] Figures 6 to 8 Various modified examples of the differential feeding network according to the embodiments of the present disclosure are shown.

[0064] like Figure 6 As shown, according to a modified example of the differential feeding network of the embodiment of the present disclosure, the first feeder FL1 may include a first bend and a second bend, the second feeder FL2 may include a third bend and a fourth bend, the first bend is arranged between the first feed output port P3 and the center point O, the second bend is arranged between the second feed output port P6 and the center point O, the third bend is arranged between the third feed output port P4 and the center point O, and the fourth bend is arranged between the fourth feed output port P5 and the center point O. The first bend to the fourth bend have the same wiring pattern and are arranged to be rotationally symmetrical about the center point O. By arranging bends on the first feeder FL1 and the second feeder FL2, miniaturization can be further achieved.

[0065] like Figure 7 As shown, according to a modified example of the differential feeding network of the embodiment of the present disclosure, the first feeder FL1 may include a first portion located between the first feed output port P3 and the center point O, and a second portion located between the second feed output port P6 and the center point O, and the first portion includes a fifth bend. The second feeder FL2 may include a third portion located between the third feed output port P4 and the center point O, and a fourth portion located between the fourth feed output port P5 and the center point O, and the third portion includes a sixth bend. The first portion of the first feeder FL1 and the fourth portion of the second feeder FL2 form a first pattern, the third portion of the second feeder FL2 and the second portion of the first feeder FL1 form a second pattern, and the first pattern and the second pattern are symmetrical to each other.

[0066] like Figure 8As shown, according to a variation example of the differential feeding network of the embodiment of the present disclosure, the first feeder FL1 may include a first portion located between the first feed output port P3 and the center point O, and a second portion located between the second feed output port P6 and the center point O, and the first portion and the second portion are not on the same straight line. The second feeder FL2 may include a third portion located between the third feed output port P4 and the center point O, and a fourth portion located between the fourth feed output port P5 and the center point O, and the third portion and the fourth portion are not on the same straight line. The first portion of the first feeder FL1 and the fourth portion of the second feeder FL2 constitute a third pattern, the third portion of the second feeder FL2 and the second portion of the first feeder FL1 constitute a fourth pattern, and the third pattern and the fourth pattern are symmetrical to each other.

[0067] According to the embodiment of the present disclosure, Figure 2 and Figure 6 As shown, the first input feeder line IFL1 is electrically connected to the first feed output port P3 of the first feeder line FL1, and the second input feeder line IFL2 is electrically connected to the third feed output port P4 of the second feeder line FL2.

[0068] According to the embodiment of the present disclosure, Figure 7 and Figure 8 As shown, the connection point between the first input feeder IFL1 and the first feeder FL1 is located between the first feed output port P3 and the center point O, and the connection point between the second input feeder IFL2 and the second feeder FL2 is located between the third feed output port P4 and the center point O.

[0069] It should be recognized that the differential feeding network can be formed into various other forms as needed, for example, forming through holes on the feeder lines, changing the line width and thickness of the routing, etc. As long as there is a connection between the two polarized feeding lines for the antenna, it is within the scope of protection of the present application, and the present application is intended to protect all possible variant implementations.

[0070] In addition, although in the previous embodiment, the phase difference between the same polarization feed input port and the two feed output ports is expressed as 180°, for example, the phase difference between the first feed output port P3 and the second feed output port P6 is expressed as 180°, those skilled in the art should understand that the phase difference between the same polarization feed input port and the two feed output ports can be an integer multiple of 180 degrees, for example, θ 16 -θ 13 =n×180°, n=1, 2, 3… θ 25 -θ 24 =n×180°, n=1, 2, 3… Among them, θ 16represents the phase difference between the first feeding input port P1 and the second feeding output port P6, θ 13 represents the phase difference between the first feeding input port P1 and the first feeding output port P3, θ 25 represents the phase difference between the second feeding input port P2 and the fourth feeding output port P5, θ 24 represents the phase difference between the second feeding input port P2 and the third feeding output port P4.

[0071] Below, Figure 6 The example of the differential feeding network shown is used as an example to illustrate the antenna according to the embodiment of the present disclosure.

[0072] Fig. 9 A schematic structural diagram of an antenna according to an embodiment of the present disclosure is shown. Fig. 9 The left side shows a top view of the antenna. Fig. 9 The right side shows a perspective view of the antenna.

[0073] like Fig. 9 As shown, the antenna according to the embodiment of the present disclosure includes a metal radiation patch 901, a differential feeding network 902, a metal reflection plate 903, and a connection structure 904 arranged between the metal radiation patch and the differential feeding network. Fig. 9 In the example of FIG. 1 , the differential feed network 902 is Figure 6 An example of a differential feeding network is shown in FIG. 9 . A metal radiation patch 901 is placed above a differential feeding network 902 , and a differential feeding network 902 is placed above a metal reflection plate 903 . Fig. 9 The antenna shown may be an integrated pure metal structure and can function normally without an additional fixing structure.

[0074] According to the embodiment of the present disclosure, Fig. 9 and Fig.10 As shown, the connection structure 904 may include four metal pillars electrically connected to the first feed output port P3 to the fourth feed output port P5 respectively, one end of each metal pillar is electrically connected to one of the first feed output port P3 to the fourth feed output port P5, and the other end of each metal pillar is electrically connected to the corresponding feeding position in the metal radiation patch 901.

[0075] right Fig. 9When designing the antenna shown, the radiation structure and the feeding structure can be designed separately. The size of the metal radiation patch 901 can be selected according to the appropriate frequency band, and the metal radiation patch 901 is fed through four rotationally symmetrical vertical metal pillars (i.e., the connecting structure 904), and four feeding ports are provided below the metal pillars. The antenna can be adjusted to a matching state by optimizing the position of the metal pillars. When designing the differential feeding network 902, the equivalent circuit diagram can be referred to, and the impedance and position of the feeding output ports (i.e., the first feeding output port P3 to the fourth feeding output port P5) of the differential feeding network 902 are consistent with the four feeding ports below the metal pillars. By adjusting the line length L of the cross structure located in the center f and line width W f , the power ratio of the feed output port of the same polarization is adjusted to 1:1, and the phase is 180 degrees. The designed radiation structure (ie, metal radiation patch 901) and the feeding structure (ie, differential feeding network 902) are combined according to the position of the feed output port to obtain the designed antenna.

[0076] Fig.11 Shows Fig. 9 The surface electric field distribution of the differential feed network of the antenna is shown.

[0077] like Fig.11 As shown in the figure, when a single feed input port is fed, power is transmitted to the two feed output ports and of the corresponding polarization, while the electric field on the other polarization path is very small, which is equivalent to the disconnected state. The lighter the color, the larger the electric field value, and the darker the color, the smaller the electric field value. It can be seen that Fig.11 The surface electric field distribution of the differential feed network shown is consistent with the technical principle description provided previously.

[0078] Fig.12 Shows Fig. 9 The S-parameter diagram of the antenna is shown. Fig.13 Shows Fig. 9 The radiation pattern of the antenna is shown. Fig.13 The left side shows the radiation pattern when phi=0 degrees. Fig.13 The right side of the diagram shows the radiation pattern when phi = 90 degrees.

[0079] like Fig.12 As shown, Fig. 9 The antenna shown has a return loss of less than -37 dB at 4.876 GHz (see curves S(1, 1) and S(2, 2)) and an isolation of greater than 24 dB (see curve S(2, 1)). Fig.13 As shown, Fig. 9The antenna shown has symmetrical radiation patterns at the two main radiation planes at phi = 0 degrees and phi = 90 degrees (see the curve in the middle part of the figure), an antenna gain of 9.5 dB, and a low cross-polarization level (see the curve in the lower part of the figure), and has good radiation characteristics.

[0080] Fig.14 Another example of a differential feed network according to an embodiment of the present disclosure is shown.

[0081] like Fig.14 As shown, the differential feeding network according to the embodiment of the present disclosure may also include four L-shaped feeding coupling components electrically connected to the first feeding output port to the fourth feeding output port, respectively. Each L-shaped feeding coupling component includes a vertical portion and a horizontal portion, one end of the vertical portion is connected to one end of the horizontal portion, and the other end of the vertical portion is connected to one of the first feeding output port to the fourth feeding output port. The horizontal portion extends in a direction toward the center point, and the extension length of the horizontal portion is less than the distance between one of the first feeding output port to the fourth feeding output port and the center point.

[0082] It should be recognized that Fig.14 The column located at the center point shown in the figure is a connection structure connecting the differential feeding network with the metal radiation patch above it, and should not be understood as a part of the differential feeding network.

[0083] According to the embodiment of the present disclosure, the vertical portion may have a cylindrical shape, and the horizontal portion may have a rectangular, circular, elliptical, or fan-shaped shape. It should be recognized that the vertical portion and the horizontal portion may have various shapes as needed, as long as the horizontal portion has a certain projection area relative to the radiation patch, that is, suitable coupling can be provided, so that the radiation patch can be fed, which is within the protection scope of the present application, and the present application is intended to protect all possible variant implementations.

[0084] Below, Fig.14 The example of the differential feeding network shown is used as an example to illustrate the antenna according to the embodiment of the present disclosure.

[0085] Fig.15 A schematic structural diagram of an antenna according to an embodiment of the present disclosure is shown. Fig.15 The left side shows a top view of the antenna. Fig.15 The right side shows an exploded perspective view of the antenna.

[0086] like Fig.15 As shown, the antenna according to the embodiment of the present disclosure includes a metal radiation patch 1501, a differential feeding network 1502, a metal reflection plate 1503, and a connection structure 1504 arranged between the metal radiation patch and the differential feeding network. Fig.15 In the example of FIG. 1 , the differential feed network 1502 is Fig.14 An example of a differential feeding network is shown. The metal radiation patch 1501 is placed above the differential feeding network 1502, and the differential feeding network 1502 is placed above the metal reflector 1503. The four feeding output ports of the differential feeding network 1502 are respectively connected to four L-shaped feeding coupling components to excite the upper metal radiation patch 1501 in a coupled manner. Each L-shaped feeding coupling component includes a vertical portion and a horizontal portion, one end of the vertical portion is connected to one end of the horizontal portion, and the other end of the vertical portion is connected to one of the first feeding output port to the fourth feeding output port. The horizontal portion extends in a direction toward the center point, and the extension length of the horizontal portion is less than the distance between one of the first feeding output port to the fourth feeding output port and the center point. The cross structure in the middle of the differential feeding network 1502 is connected to the center point of the metal radiation patch 1501 through a metal column (i.e., the connecting structure 1504). Fig.15 The antenna shown may be a unitary pure metal structure.

[0087] According to the embodiment of the present disclosure, Fig.15 As shown, the connection structure 1504 may include a central connection column connected to the center point of the differential feed network 1502 and the center point of the metal radiation patch 1501. The height of the central connection column is greater than the height of the vertical portion of the L-shaped feed coupling component.

[0088] Fig.16 Shows Fig.15 The surface electric field distribution of the antenna’s metal radiation patch and differential feed network is shown. Fig.16 The left side shows the surface electric field distribution of the metal radiation patch. Fig.16 The right side of shows the surface electric field distribution of the differential feeding network.

[0089] like Fig.16 As shown in the figure, when a single feed input port is fed, power is transmitted to the two feed output ports and of the corresponding polarization, while the electric field on the other polarization path is very small, which is equivalent to the disconnected state. The lighter the color, the larger the electric field value, and the darker the color, the smaller the electric field value. It can be seen that Fig.16 The surface electric field distribution of the differential feeding network shown is consistent with the technical principle description provided previously. On the other hand, the electric field strength at the center of the metal radiation patch is the smallest, which is equivalent to a disconnected state. Since the electric field strength at the center of the metal radiation patch and the center of the differential feeding network are very small, setting a metal center connecting column for support between the two to connect the metal radiation patch and the differential feeding network will not introduce new current distribution, and the antenna can maintain the original working mode.

[0090] Fig.17 Shows Fig.15 The S-parameter diagram of the antenna is shown. Fig.18 Shows Fig.15 The radiation pattern of the antenna is shown. Fig.18 The left side shows the radiation pattern when phi=0 degrees. Fig.18 The right side of the diagram shows the radiation pattern when phi = 90 degrees.

[0091] like Fig.17 As shown, Fig.15 The antenna shown has a return loss of less than -21 dB at 4.89 GHz (see curves S(1, 1) and S(2, 2)) and an isolation of greater than 32 dB (see curve S(2, 1)). Fig.18 As shown, Fig.15 The antenna shown has symmetrical radiation patterns at the two main radiation planes of phi=0 degrees and phi=90 degrees (see the curve in the middle part of the figure), an antenna gain of 8.8dB, and a low cross-polarization level (see the curve in the lower part of the figure). It has good radiation characteristics and can be used as a base station antenna unit.

[0092] According to the embodiment of the present disclosure, a grounded short-circuit point may be set at the center point of the differential feeding network.

[0093] Through the equivalent circuit analysis of the antenna, it can be known that a grounded short-circuit point can be set at the center point O of the differential feed network. In actual antenna arrays, the asymmetric coupling between the antenna's radiation structure and the feeding structure cannot be completely avoided. Although this asymmetry has little effect on the antenna pattern, it still causes the current on the differential feed network to not maintain absolute symmetry. Setting a grounded short-circuit point at the center point O can ensure that the amplitude and phase difference of each polarized differential port are closer to the ideal state, ensuring a more symmetrical pattern.

[0094] Fig.19 Various modified examples of the antenna according to the embodiment of the present disclosure are shown.

[0095] like Fig.19 As shown, according to an embodiment of the present disclosure, the vertical portion of the L-shaped feed coupling component of the differential feed network is formed to be connected to the feed line and the horizontal portion of the L-shaped feed coupling component by means of rounded corners.

[0096] According to an embodiment of the present disclosure, the metal radiation patch may have one of a square, a rectangle or a circle, or any other suitable shape. The metal radiation patch may also have at least one of the following structures: a groove, a bend or a droop. The metal radiation patch may have a stacked structure of multiple layers of patches.

[0097] According to the embodiment of the present disclosure, the central connecting column is formed of a metal material or a non-metal material, that is, a pure metal antenna structure can use a non-metal support, or be attached to a non-metal structure. For example, around a structure with a small surface electric field distribution of the antenna, a non-metal structure can be used instead of a metal structure for support. When applied to a dual-frequency antenna array, common-mode interference to lower-frequency antenna units can be avoided, while also being adaptable to a variety of processing techniques and still maintaining a high radiation efficiency. Fig.19 It is shown that a central connecting column made of non-metallic material or other non-metallic structural members that can play a supporting and / or positioning role are arranged below the central position of the metal radiation patch.

[0098] The antenna according to the embodiment of the present disclosure can be formed into an integrated pure metal antenna, with low cross polarization and symmetrical radiation pattern, and has higher efficiency. Without the need for additional non-metallic support structures, the antenna according to the embodiment of the present disclosure is easy to assemble and has better environmental friendliness.

[0099] In the antenna according to the embodiment of the present disclosure, a structure made of non-metallic materials can be used instead of a structure made of metallic materials for support, and the non-metallic part can be set at the position where the electric field distribution is minimal. Therefore, it can also have the advantages of low loss and high efficiency, and there is no common mode interference, and it can be applied to compact dual-frequency array antennas.

[0100] Fig. 20 A modified example of the antenna according to the embodiment of the present disclosure is shown.

[0101] like Fig. 20 As shown, the antenna can be made using traditional printed circuit board (PCB) technology or plastic modules, where metal materials are attached to non-metallic dielectric materials. In this way, symmetrical radiation patterns and low cross-polarization can still be achieved. However, due to the use of non-metallic dielectric materials in areas with dense electric fields, the radiation efficiency of the antenna will be lost.

[0102] Fig.21 An example of a matrix differential feed network according to an embodiment of the present disclosure is shown.

[0103] like Fig.21 As shown, an embodiment of the present disclosure further provides a matrix differential feeding network, comprising a plurality of unit differential feeding networks arranged in a matrix, the unit differential feeding network comprising a differential feeding network according to each embodiment of the present disclosure, wherein the first input feed lines of at least two unit differential feeding networks located in the same column are electrically connected to each other and the second input feed lines are electrically connected to each other, and the at least two unit differential feeding networks are fed via the same first feeding input port and the same second feeding input port.

[0104] exist Fig.21 In the example of the matrix differential feeding network shown, a small-pitch array of 4×8 scale with a horizontal spacing of 0.35 times the wavelength is shown. It can be seen that the differential feeding network has a very small wiring size, thus effectively alleviating the pressure of the line layout of the differential feeding network of the compact array antenna.

[0105] It should be recognized that although Fig.21 It is shown that the first input feeders of the unit differential feeding networks located in the same column are electrically connected to each other and the second input feeders are electrically connected to each other, but the present disclosure is not limited thereto. According to a specific implementation process, the unit differential feeding networks located in the same column can be divided into a plurality of sub-arrays, and the unit differential feeding networks in the same sub-array are connected to each other, but not necessarily connected between the sub-arrays.

[0106] The present disclosure has disclosed example embodiments, and although specific terms are employed, they are used and should be interpreted only in a general illustrative sense and not for limiting purposes. In some instances, it will be apparent to those skilled in the art that, unless otherwise expressly stated, features, characteristics, and / or elements described in conjunction with a particular embodiment may be used alone or in combination with features, characteristics, and / or elements described in conjunction with other embodiments. Therefore, those skilled in the art will appreciate that various changes in form and detail may be made without departing from the scope of the present disclosure as set forth in the appended claims.

Claims

1. A differential feeding network for a dual-polarized antenna, comprising: a first feeder and a second feeder intersecting each other, wherein the first feeder intersects the second feeder at a center point, The first feeder includes a first feed output port and a second feed output port respectively arranged at two ends of the first feeder, The second feeder includes a third feed output port and a fourth feed output port respectively arranged at two end points of the second feeder, The differential feed network further comprises a first input feed line and a second input feed line, One end of the first input feeder is provided with a first feeding input port, and the other end of the first input feeder is electrically connected to the first feeder. One end of the second input feeder is provided with a second feed input port, and the other end of the second input feeder is electrically connected to the second feeder. Wherein, the first feeder line and the second feeder line are electrically connected to each other at the center point.

2. The differential feed network according to claim 1, wherein: The first feeder and the second feeder are integrally formed.

3. The differential feed network according to claim 1, wherein: The first feeder includes a first bending portion and a second bending portion, and the second feeder includes a third bending portion and a fourth bending portion. The first bending portion is arranged between the first feeding output port and the center point, The second bending portion is arranged between the second feeding output port and the center point, The third bending portion is arranged between the third feeding output port and the center point, The fourth bending portion is arranged between the fourth feeding output port and the center point, The first to fourth bent portions have the same wiring pattern and are arranged rotationally symmetrically about the center point.

4. The differential feed network according to claim 1, wherein: The first input feeder is electrically connected to the first feed output port of the first feeder, The second input feeder is electrically connected to the third feed output port of the second feeder.

5. The differential feed network according to claim 1, wherein: The connection point between the first input feeder and the first feeder is located between the first feed output port and the center point, A connection point between the second input feeder and the second feeder is located between the third feed output port and the center point.

6. The differential feed network according to claim 1, wherein: The first feed line includes a first portion located between the first feed output port and the center point, and a second portion located between the second feed output port and the center point, and the first portion includes a fifth bend, The second feeder line includes a third portion located between the third feed output port and the center point, and a fourth portion located between the fourth feed output port and the center point, and the third portion includes a sixth bend. The first portion of the first feeder and the fourth portion of the second feeder form a first pattern, the third portion of the second feeder and the second portion of the first feeder form a second pattern, and the first pattern and the second pattern are symmetrical to each other.

7. The differential feed network according to claim 1, wherein: The first feed line includes a first portion located between the first feed output port and the center point, and a second portion located between the second feed output port and the center point, and the first portion and the second portion are not on the same straight line, The second feeder line includes a third portion located between the third feed output port and the center point, and a fourth portion located between the fourth feed output port and the center point, and the third portion and the fourth portion are not on the same straight line, The first portion of the first feeder and the fourth portion of the second feeder form a third pattern, the third portion of the second feeder and the second portion of the first feeder form a fourth pattern, and the third pattern and the fourth pattern are symmetrical to each other.

8. The differential feeding network according to claim 1, further comprising four L-shaped feeding coupling components electrically connected to the first feeding output port to the fourth feeding output port, respectively, wherein: Each L-shaped feed coupling component comprises a vertical portion and a horizontal portion, One end of the vertical portion is connected to one end of the horizontal portion, and the other end of the vertical portion is connected to one of the first feed output port to the fourth feed output port. The horizontal portion extends in a direction toward the center point, and an extending length of the horizontal portion is smaller than a distance between one of the first to fourth feeding output ports and the center point.

9. The differential feed network according to claim 8, wherein: The vertical portion has a cylindrical shape.

10. The differential feed network according to any one of claims 1 to 9, wherein: The differential feeding network is formed of a metal material.

11. A matrix differential feeding network, comprising a plurality of unit differential feeding networks arranged in a matrix, wherein the unit differential feeding network comprises a differential feeding network according to any one of claims 1 to 10, wherein: The first input feed lines of at least two unit differential feeding networks in the same column are electrically connected to each other and the second input feed lines are electrically connected to each other, and the at least two unit differential feeding networks are fed via the same first feeding input port and the same second feeding input port.

12. An antenna comprising a metal radiation patch, a differential feeding network and a metal reflector, wherein the differential feeding network comprises the differential feeding network according to any one of claims 1 to 7, The metal radiation patch is placed above the differential feeding network, and the differential feeding network is placed above the metal reflection plate. The antenna also includes a connection structure disposed between the metal radiation patch and the differential feed network.

13. The antenna according to claim 12, wherein: The connection structure includes four metal pillars electrically connected to the first feed output port to the fourth feed output port respectively. One end of each metal column is electrically connected to one of the first feeding output port to the fourth feeding output port, and the other end of each metal column is electrically connected to a corresponding feeding position in the metal radiation patch.

14. The antenna according to claim 12, wherein: The differential feeding network further includes four L-shaped feeding coupling components electrically connected to the first feeding output port to the fourth feeding output port, respectively. Each L-shaped feed coupling component comprises a vertical portion and a horizontal portion, One end of the vertical portion is connected to one end of the horizontal portion, and the other end of the vertical portion is connected to one of the first feed output port to the fourth feed output port. The horizontal portion extends in a direction toward the center point, and an extension length of the horizontal portion is less than a distance between one of the first feeding output port to the fourth feeding output port and the center point, The connection structure includes a central connection column, one end of which is connected to the central point, the other end of which is connected to the center of the metal radiation patch, and the height of the central connection column is greater than the height of the vertical portion.

15. The antenna according to claim 14, wherein: The central connecting column is formed of a metal material, or the central connecting column is formed of a non-metal material.

16. The antenna according to any one of claims 12 to 15, wherein: A short-circuit point connected to ground is provided at the center point of the differential feed network.

17. The antenna according to claim 12, wherein: The metal radiation patch has at least one of the following structures: a groove, a bend or a droop.

18. The antenna according to claim 12, wherein: The metal radiation patch has a stacked structure of multiple layers of patches.

Images