A broadband dual circularly polarized microstrip array antenna and communication terminal

Abstract

The present application provides a broadband dual-circular polarization microstrip array antenna and a communication terminal, which relate to the field of communication technology and include a metal backplane, a microstrip dielectric plate assembly, and a broadband antenna unit and a dual-rotational feeding network located in the microstrip dielectric plate assembly and interconnected. The microstrip dielectric plate assembly includes a microstrip dielectric composite plate, which includes a stacked first dielectric plate and a second dielectric plate. A microstrip metal stratum is sandwiched between the first dielectric plate and the second dielectric plate. The first dielectric plate is opposite to and spaced from the metal backplane to form a back cavity between the first dielectric plate and the metal backplane. A bottom feed structure with the first dielectric plate passing through its end is provided in the back cavity. Thus, a good electrical connection between the microstrip metal stratum and the metal backplane can be formed with the help of the bottom feed structure.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a broadband dual circularly polarized microstrip array antenna and a communication terminal. Background Art

[0002] Wideband dual circularly polarized antennas offer strong resistance to interference and attenuation, and are widely used in remote sensing, telemetry, satellite communications, and other fields. Dual circularly polarized antennas can be implemented in a variety of configurations, with microstrip antennas being widely used due to their low profile, light weight, and ease of fabrication. To achieve dual circular polarization with microstrip antennas, linearly polarized microstrip antenna structures can be used in conjunction with orthogonal power dividers and couplers, often forming an array using a sequential rotating feed network.

[0003] In many application scenarios, the antenna is required to have a metal backplane that is easy to fix and load. Therefore, part of the feed network will face the metal backplane, which requires a certain thickness of air layer between the metal backplane and this part of the feed network for isolation. However, this also makes the air layer separate the metal backplane and the microstrip metal stratum, making it difficult for the metal backplane and the microstrip metal stratum to achieve good electrical contact under backfeed conditions. Summary of the Invention

[0004] The purpose of this application is to address the deficiencies in the above-mentioned prior art and provide a broadband dual circularly polarized microstrip array antenna and a communication terminal, which can achieve good electrical contact between the metal backplane and the microstrip metal stratum under backfeed conditions.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of the present application are as follows:

[0006] According to one aspect of an embodiment of the present application, a broadband dual circularly polarized microstrip array antenna is provided, comprising a metal backplane, a microstrip dielectric plate assembly, and a broadband antenna unit and a dual-rotational feeding network located in the microstrip dielectric plate assembly and interconnected. The microstrip dielectric plate assembly comprises a microstrip dielectric composite plate, the microstrip dielectric composite plate comprises a stacked first dielectric plate and a second dielectric plate, a microstrip metal ground layer is sandwiched between the first dielectric plate and the second dielectric plate, the first dielectric plate is opposite to and spaced from the metal backplane to form a back cavity between the first dielectric plate and the metal backplane, a bottom feed structure with the first dielectric plate passed through its end is provided in the back cavity, and the microstrip metal ground layer is electrically connected to the metal backplane via the bottom feed structure.

[0007] Optionally, a feeding through hole is provided on the microstrip dielectric composite board, which sequentially passes through the microstrip dielectric composite board and the bottom feeding structure, and the dual-rotation feeding network is used to electrically connect to the microwave connector in the feeding through hole.

[0008] Optionally, the dual-rotational feeding network includes a first rotational feeding network and a second rotational feeding network respectively connected to the broadband antenna unit, the first rotational feeding network is located on the surface of the first dielectric plate facing away from the second dielectric plate, and the second rotational feeding network is located on the surface of the second dielectric plate facing away from the first dielectric plate; the bottom feeding structure includes two, and the feeding holes corresponding to each of the two bottom feeding structures correspond one-to-one to the first rotational feeding network and the second rotational feeding network respectively; the first rotational feeding network is led out to the surface of the second dielectric plate facing away from the first dielectric plate through the switching through hole passing through the microstrip dielectric composite plate, and the first rotational feeding network and the second rotational feeding network are respectively electrically connected to the microwave connector through the corresponding feeding through holes.

[0009] Optionally, the broadband dual circularly polarized microstrip array antenna further includes a support member, which is supported between the metal back plate and the first dielectric plate.

[0010] Optionally, the support member includes a plurality of step structures fixed to the metal back plate and distributed along the periphery of the metal back plate, two adjacent step structures are arranged at intervals, and the first dielectric plate is overlapped on the table of the step structure.

[0011] Optionally, the support member further includes a plurality of pillars supported on the first dielectric plate and the metal back plate, and the plurality of pillars are evenly distributed in the back cavity.

[0012] Optionally, the broadband antenna unit includes a first metal patch and a broadband branch line coupler, the first metal patch is located on the surface of the second dielectric plate facing away from the first dielectric plate, the broadband branch line coupler is located on the surface of the first dielectric plate facing away from the second dielectric plate, the first metal patch is connected to the broadband branch line coupler through a connecting through hole passing through the microstrip dielectric composite plate, and the broadband branch line coupler is connected to the dual-rotation feeding network.

[0013] Optionally, the microstrip dielectric plate assembly also includes a third dielectric plate opposite to and spaced apart from the second dielectric plate to form a cavity between the third dielectric plate and the second dielectric plate, and the broadband antenna unit also includes a second metal patch located on the third dielectric plate close to the surface of the second dielectric plate, and the second metal patch corresponds to the first metal patch.

[0014] Optionally, the broadband dual circularly polarized microstrip array antenna includes a plurality of broadband antenna units arranged in a rectangular array, and four adjacent broadband antenna units are rotated sequentially to form a group of antenna subarrays.

[0015] Another aspect of an embodiment of the present application provides a communication terminal comprising any one of the above-mentioned broadband dual circularly polarized microstrip array antennas.

[0016] The beneficial effects of this application include:

[0017] The present application provides a broadband dual-circular polarization microstrip array antenna and a communication terminal, including a metal backplane, a microstrip dielectric plate assembly, and a broadband antenna unit and a dual-rotational feeding network located in the microstrip dielectric plate assembly and interconnected. The microstrip dielectric plate assembly includes a microstrip dielectric composite plate, which includes a stacked first dielectric plate and a second dielectric plate. A microstrip metal stratum is sandwiched between the first dielectric plate and the second dielectric plate. The first dielectric plate is opposite to and spaced from the metal backplane to form a back cavity between the first dielectric plate and the metal backplane. A bottom feed structure with the first dielectric plate passing through its end is provided in the back cavity. Thus, a good electrical connection between the microstrip metal stratum and the metal backplane can be formed with the help of the bottom feed structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 A top view of a broadband dual circularly polarized microstrip array antenna provided in an embodiment of the present application;

[0020] Figure 2 A side view of a broadband dual circularly polarized microstrip array antenna provided in an embodiment of the present application;

[0021] Figure 3 for Figure 2 A partial enlarged view of the

[0022] Figure 4 A schematic structural diagram of a broadband antenna unit provided in an embodiment of the present application;

[0023] Figure 5a A top view of an antenna subarray provided in an embodiment of the present application;

[0024] Figure 5b A bottom view of an antenna subarray provided in an embodiment of the present application;

[0025] Figure 6a A feeding schematic diagram of a second rotational direction feeding network provided in an embodiment of the present application;

[0026] Figure 6b A feeding schematic diagram of a first rotational direction feeding network provided in an embodiment of the present application;

[0027] Figure 7 A schematic structural diagram of a step structure provided in an embodiment of the present application;

[0028] Figure 8 A schematic diagram of the input standing wave ratio and frequency of a left-hand and right-hand port provided in an embodiment of the present application;

[0029] Figure 9 A schematic diagram of isolation and frequency provided in an embodiment of the present application;

[0030] Figure 10 A schematic diagram of the axial ratio and frequency of left-hand and right-hand circular polarization provided in an embodiment of the present application;

[0031] Figure 11 A schematic diagram of left-hand and right-hand circular polarization gain and frequency provided in an embodiment of the present application.

[0032] Icons: 100- broadband antenna unit; 110- first rotational feeding network; 120- second rotational feeding network; 130- bottom feed structure; 140- step structure; 141- corner step structure; 1411- first step surface; 1412- second step surface; 142- side step structure; 150- radome; 160- microstrip dielectric plate assembly; 170- microstrip dielectric composite plate; 171- first dielectric plate; 172- second dielectric plate; 180- third dielectric plate; 210- metal backplane; 220- pillar; 231- first metal patch; 2311- adjustment branch; 232- second metal patch; 240- broadband branch line coupler; 241- first rotational port; 242- second rotational port; 250- metal probe; 260- antenna subarray; 270- screw; 280- transfer microstrip line. DETAILED DESCRIPTION

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application as claimed, but merely represents selected embodiments of the present application. It should be noted that, unless there is a conflict, the various features of the embodiments of the present application may be combined with each other, and the combined embodiments are still within the scope of protection of the present application.

[0035] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of this application is typically placed when in use. These terms are used solely to facilitate the description of this application and to simplify the description, and therefore should not be construed as limiting this application. Furthermore, the terms "first," "second," and "third," etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0036] It should also be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0037] One aspect of an embodiment of the present application provides a broadband dual circularly polarized microstrip array antenna. When the antenna includes an air layer formed by a metal backplate 210, the antenna utilizes a bottom feed structure 130 to achieve good electrical contact between the metal backplate 210 and the microstrip metal layer. This improves the engineering applicability of the broadband dual circularly polarized microstrip array antenna. The embodiments of the present application are described below with reference to the accompanying drawings.

[0038] Please refer to Figure 1 As shown, the broadband dual circularly polarized microstrip array antenna includes a metal backplane 210, a microstrip dielectric plate assembly 160, a broadband antenna unit 100 and a dual-rotational feeding network, wherein the broadband antenna unit 100 can be multiple and arranged in the form of an array on the microstrip dielectric plate assembly 160, and the dual-rotational feeding network is also correspondingly arranged on the microstrip dielectric plate assembly 160 and connected to the broadband antenna unit 100, thereby forming a dual circularly polarized antenna.

[0039] Please refer to Figure 2 and Figure 3 The metal backplate 210 and the microstrip dielectric plate assembly 160 are relative and spaced apart to form an air layer therebetween. Specifically, the microstrip dielectric plate assembly 160 includes a microstrip dielectric composite plate 170. The dual-rotational feeding network can be located on the microstrip dielectric composite plate 170. The microstrip dielectric composite plate 170 includes a stacked first dielectric plate 171 and a second dielectric plate 172. A microstrip metal ground layer is also sandwiched between the first dielectric plate 171 and the second dielectric plate 172, so that the first dielectric plate 171 and the second dielectric plate 172 can be back-to-back grounded, forming a relatively compact and simple structure to lay out the dual-rotational feeding network.

[0040] The metal backplate 210 and the first dielectric plate 171 are opposite to and spaced apart from each other, thereby forming a back cavity with an air layer between the metal backplate 210 and the first dielectric plate 171. The air layer can separate the first dielectric plate 171 and the metal backplate 210. In order to achieve electrical connection between the microstrip metal stratum and the metal backplate 210 under backfeed conditions, a bottom feed structure 130 can be provided in the back cavity. The bottom end of the bottom feed structure 130 is electrically connected to the metal backplate 210, and the top end of the bottom feed structure 130 passes through the first dielectric plate 171, thereby being electrically connected to the microstrip metal stratum. Thus, with the help of the bottom feed structure 130, a good electrical connection between the microstrip metal stratum and the metal backplate 210 can be formed.

[0041] In some embodiments, the bottom-feed structure 130 can be a conductive metal block structure, such as copper, gold, or silver. The bottom-feed structure 130 can also have various shapes, such as a square or a cylinder, and the corresponding cross-sectional shape can be various shapes, such as a circle, a triangle, a quadrilateral, or a pentagon. This application does not impose any specific restrictions on this, and a reasonable selection can be made based on actual needs.

[0042] In some embodiments, the metal backplate 210 can be milled integrally with the bottom feed structure 130, that is, integrally formed; of course, in other embodiments, the metal backplate 210 and the bottom feed structure 130 can also be formed separately and then connected and assembled.

[0043] Optionally, in order to achieve bottom feeding of the antenna, combine Figure 1 and Figure 3 As shown, a feed through-hole is provided on the microstrip dielectric composite board 170, sequentially penetrating the microstrip dielectric composite board 170 and the bottom feed structure 130. Thus, a dual-rotational feed network disposed on the microstrip dielectric composite board 170 can be connected to a microwave connector (e.g., an SMA connector) within the feed through-hole, thereby enabling bottom feeding of the antenna via the bottom feed structure 130. It should be understood that when the dual-rotational feed network is electrically connected to the microwave connector within the feed through-hole, it should be insulated and isolated from the bottom feed structure 130 by a dielectric.

[0044] Optional, such as Figure 1 As shown, the dual-handed feeding network includes a first handed feeding network 110 and a second handed feeding network 120 , wherein the first handed feeding network 110 may be a left-handed circularly polarized sequential rotation feeding network, and the second handed feeding network 120 may be a right-handed circularly polarized sequential rotation feeding network.

[0045] The first rotational feed network 110 can be located on the lower surface of the microstrip dielectric composite plate 170, opposite the metal backplate 210. The first rotational feed network 110 is isolated from the metal backplate 210 by an air layer. The second rotational feed network 120 can be located on the upper surface of the microstrip dielectric composite plate 170. Specifically, the first rotational feed network 110 is located on the surface of the first dielectric plate 171 facing away from the second dielectric plate 172, while the second rotational feed network 120 is located on the surface of the second dielectric plate 172 facing away from the first dielectric plate 171. As a result, the first rotational feed network 110 and the second rotational feed network 120 can be distributed on the first dielectric plate 171 and the second dielectric plate 172, resulting in a relatively compact and simple structure.

[0046] In order to facilitate the feeding of the first rotational feeding network 110 and the second rotational feeding network 120, as shown in FIG. Figure 1 As shown, two bottom feed structures 130 can be provided, wherein the feeding through hole corresponding to one bottom feed structure 130 is used for feeding the first rotational direction feeding network 110 , and the feeding through hole corresponding to the other bottom feed structure 130 is used for feeding the second rotational direction feeding network 120 .

[0047] Please combine Figure 1 and Figure 6a As shown, specifically, since the second rotational feeding network 120 is located on the upper surface of the second dielectric plate 172, and the upper end opening of the corresponding feeding through-hole is also located on the upper surface of the second dielectric plate 172, the second rotational feeding network 120 can be directly connected to the microwave connector in the feeding through-hole through the upper end opening of the feeding through-hole.

[0048] Please combine Figure 1 and Figure 6b As shown, specifically, since the first rotational feeding network 110 is located on the lower surface of the first dielectric plate 171, and the upper end opening of the corresponding feeding through-hole is located on the upper surface of the second dielectric plate 172, the first rotational feeding network 110 cannot be directly led out through the feeding through-hole. Therefore, a transfer through-hole can be provided on the microstrip dielectric composite plate 170, penetrating the first dielectric plate 171, the microstrip metal layer, and the second dielectric plate 172. In this case, the first rotational feeding network 110 located on the lower surface of the first dielectric plate 171 can first be led to the upper surface of the second dielectric plate 172 through the transfer through-hole, and then introduced into the corresponding feeding through-hole from the upper surface of the second dielectric plate 172 via a short transfer microstrip line 280 and connected to the microwave connector in the feeding through-hole.

[0049] Optional, such as Figure 2 and Figure 3As shown, the microstrip dielectric plate assembly 160 further includes a third dielectric plate 180 , which is located above the second dielectric plate 172 . The third dielectric plate 180 is opposite to and spaced from the second dielectric plate 172 to form a cavity between the third dielectric plate 180 and the second dielectric plate 172 .

[0050] The broadband antenna unit 100 includes a first metal patch 231 and a second metal patch 232, wherein the first metal patch 231 is located on the upper surface of the second dielectric plate 172, and the second metal patch 232 is located on the third dielectric plate 180 close to the second metal patch 232 on the surface of the second dielectric plate 172, that is, located on the lower surface of the third dielectric plate 180. The second metal patch 232 corresponds to the first metal patch 231, thereby effectively widening the frequency band of the antenna.

[0051] In order to maintain a uniform spacing between the first dielectric plate 171 and the metal back plate 210, and between the second dielectric plate 172 and the third dielectric plate 180, this can be achieved by combining the bottom feed structure 130 with the support member. Figure 2 and Figure 3 As shown, the broadband dual circularly polarized microstrip array antenna further includes a support member, which can be supported between the metal back plate 210 and the first dielectric plate 171 , the second dielectric plate 172 and the third dielectric plate 180 .

[0052] In some embodiments, as Figure 7 As shown, the support member includes a step structure 140, which can be a two-level step. There can be multiple step structures 140. The bottom surfaces of the multiple step structures 140 are fixed to the upper surface of the metal back plate 210, and the multiple step structures 140 are evenly and spaced along the periphery of the metal back plate 210. Therefore, the weight of the support member can be effectively reduced by discontinuous arrangement, which is conducive to the lightweighting of the broadband dual circular polarization microstrip array antenna. The lower surface of the microstrip dielectric composite plate 170 can be aligned with the first step surface 1411 of the step structure 140, and the lower surface of the third dielectric plate 180 can be aligned with the second step surface 1412 of the step structure 140. Therefore, the height difference between the step surfaces and the bottom surface of the step structure 140 is used to maintain the spacing between the first dielectric plate 171 and the metal back plate 210, and between the second dielectric plate 172 and the third dielectric plate 180.

[0053] For example Figure 7 As shown, the step structure 140 can be set as a side step structure 142 and a corner step structure 141 according to its position, combined with Figure 1 As shown, four corner step structures 141 are distributed at the four corners of the antenna, and four side step structures 142 are respectively located in the middle of each side to form a good support.

[0054] On this basis, the bottom-feed structure 130 in the back cavity can also be supported between the microstrip dielectric composite board 170 and the metal backboard 210 .

[0055] Optional, such as Figure 2 and Figure 3 As shown, the support member also includes a support post 220. The support post 220 can penetrate the microstrip dielectric composite plate 170 and connect to the metal backplate 210 and the third dielectric plate 180, respectively, thereby maintaining a spacing between the first dielectric plate 171 and the metal backplate 210, and between the second dielectric plate 172 and the third dielectric plate 180. When the antenna array is large, multiple support posts 220 can be provided, evenly distributed across the antenna array, to maintain a uniform spacing between the first dielectric plate 171 and the metal backplate 210, and between the second dielectric plate 172 and the third dielectric plate 180 at all locations. The support posts 220 can be metal studs.

[0056] It should be understood that the integral body formed by the first dielectric plate 171 and the second dielectric plate 172 can be secured by welding with metal probes 250 or by gluing using multilayer board technology. The bottom-feed structure 130 and the second dielectric plate 172, the bottom-feed structure 130 and the metal backplate 210, the metal backplate 210 and the support 220, and the metal backplate 210 and the step structure 140 can be secured by screws 270. The size and position of the step structure 140, the size and position of the metal studs, and the size and position of the bottom-feed structure 130 can be adjusted according to actual design requirements.

[0057] Optional, such as Figure 2 and Figure 3 As shown, the outer surface of the antenna can also be designed with an antenna cover 150 as needed. Since the cavity formed by various supporting parts and the metal backplate 210 is open, the antenna cover 150 needs to form a sealed package for the entire antenna structure. The specific materials and processes can be customized as needed.

[0058] Optional, such as Figure 4As shown, the broadband antenna unit 100 also includes a broadband branch line coupler 240, which is located on the lower surface of the first dielectric plate 171. In order to enable the first metal patch 231 located on the surface of the second dielectric plate 172 to be connected to the broadband branch line coupler 240, a connecting through hole that penetrates the microstrip dielectric composite plate 170 can also be opened on the microstrip dielectric composite plate 170. Thus, the first metal patch 231 can be connected to the broadband branch line coupler 240 through two microstrip lines with adjustment branches 2311 through the metal probe 250 in the connecting through hole, and then the broadband branch line coupler 240 is connected to the dual-rotation feeding network to respectively realize left-handed circularly polarized radiation and right-handed circularly polarized radiation of the broadband antenna unit 100. It should be understood that the side lengths of the first metal patch 231 and the second metal patch 232 and their mutual spacing, the width and length of the adjustment branch 2311, the diameter of the metal probe 250 and the diameter of the corresponding circular hole on the microstrip metal formation, and the size of the broadband branch line coupler 240 can be adjusted and optimized according to design requirements, and this application does not impose any specific restrictions on them.

[0059] Specifically, the first rotational feeding network 110 is located on the lower surface of the first dielectric plate 171. Therefore, the first rotational feeding network 110 can be directly connected to the first rotational port 241 (left-handed port) of the broadband branch-line coupler 240, which is also located on the lower surface of the first dielectric plate 171. Since the second rotational feeding network 120 is located on the upper surface of the second dielectric plate 172, the second rotational feeding network 120 cannot be directly connected to the broadband branch-line coupler 240 located on the lower surface of the first dielectric plate 171. Therefore, the second rotational feeding network 120 can be connected to the second rotational port 242 (right-handed port) of the broadband branch-line coupler 240 via a through-hole extending through the microstrip dielectric composite plate 170.

[0060] Optional, such as Figure 1 As shown, the broadband dual circularly polarized microstrip array antenna includes a plurality of broadband antenna units 100 arranged in a rectangular array, and four adjacent broadband antenna units 100 are rotated sequentially to form a group of antenna sub-arrays 260, namely Figure 1 16 broadband antenna units 100 are shown, and form 4 antenna sub-arrays 260.

[0061] The four antenna subarrays 260 are connected by a two-stage power splitter network to achieve equal amplitude and phase array operation. The two-stage power splitter network for feeding the first and second rotational directions is composed of T-shaped power splitters, ultimately forming an array antenna. Figure 4 Each of the four broadband antenna units 100 in the embodiment forms a sub-array in a sequentially rotating manner (e.g. Figure 5a and Figure 5b As shown), the spacing between the broadband antenna units 100 can be adjusted according to the requirements of the array design.

[0062] The broadband antenna unit 100 within each antenna subarray 260 implements dual circular polarization feeding via a first rotational feed network 110 (left-hand circular polarization sequential rotation feed network) and a second rotational feed network 120 (right-hand circular polarization sequential rotation feed network). The left-hand circular polarization sequential rotation feed network and the right-hand circular polarization sequential rotation feed network are located on the lower surface of the first dielectric plate 171 and the upper surface of the second dielectric plate 172, respectively. They are mainly composed of Wilkinson power dividers connected by microstrip lines of different lengths. The difference in the length of the microstrip lines satisfies the phase required for the unit sequential rotation feeding to form circular polarization, forming Figure 5a 、 Figure 5b The phase lag sequence is 0°, -90°, -180°, and -270°. The phase lag sequence for the left-handed circularly polarized feed network and the right-handed circularly polarized feed network conforms to the four-finger bending orientation of the left and right hands, respectively. The connection between the two feed networks and the broadband antenna unit 100 through the microstrip dielectric composite board 170 is achieved through a metal probe 250 and a through-hole. At the location of the metal probe 250, a circular area is etched on the microstrip metal layer to ensure upper and lower conductivity of the metallized via.

[0063] In some embodiments, the thickness of the first dielectric plate 171 is 1 mm, the thickness of the second dielectric plate 172 is 1 mm, and the thickness of the third dielectric plate 180 is 1.5 mm.

[0064] In some embodiments, the thickness of the bottom feed structure 130 is 6 mm.

[0065] In some embodiments, the distance between the first dielectric plate 171 and the metal back plate 210 is 5 mm, and the distance between the second dielectric plate 172 and the third dielectric plate 180 is 8 mm.

[0066] As can be seen from the above embodiments, the present application utilizes a broadband dual circularly polarized antenna based on a broadband dual linear polarized microstrip antenna and a broadband branch line coupler 240 as a unit, and realizes a lightweight broadband dual circularly polarized microstrip array antenna by sequential rotation and conventional arrangement, combined with the bottom feed structure 130 grounding method and the step structure 140 + support 220 cavity construction method of the present application. The broadband dual circularly polarized microstrip array antenna in the present application can achieve a left-handed and right-handed polarized feed port input standing wave ratio of less than 1.4 (such as 1.4) within the frequency range of 2.15GHz-2.55GHz (relative bandwidth 17%). Figure 8 As shown), the isolation is greater than 15dB (as shown Figure 9 As shown), the main radiation direction axial ratio is less than 1.6dB (as shown Figure 10 As shown), the gain is greater than 22.7dBi (as shown Figure 11The broadband circularly polarized microstrip array antenna in this application can be fed through a bottom-feed method, making it more widely applicable and convenient. In addition, the step structure 140 is combined with the support 220 to construct the cavity required for antenna operation, which can effectively achieve weight reduction.

[0067] Another aspect of the present application provides a communication terminal comprising any of the aforementioned broadband dual circularly polarized microstrip array antennas. By applying the broadband dual circularly polarized microstrip array antenna to the communication terminal, power can be fed through a bottom-feed method, effectively reducing the weight of the communication terminal. The communication terminal in this application may be a mobile device, a user terminal, a wireless communication device, or the like.

[0068] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A broadband dual circularly polarized microstrip array antenna, characterized in that: The invention comprises a metal backplane, a microstrip dielectric plate assembly, and a broadband antenna unit and a dual-rotational feeding network located on and interconnected with the microstrip dielectric plate assembly. The microstrip dielectric plate assembly comprises a microstrip dielectric composite plate, which comprises a first dielectric plate and a second dielectric plate stacked together. A microstrip metal ground layer is sandwiched between the first dielectric plate and the second dielectric plate. The first dielectric plate is opposite to and spaced from the metal backplane to form a back cavity between the first dielectric plate and the metal backplane. A bottom feed structure with the first dielectric plate passing through its end is provided in the back cavity. The microstrip metal ground layer is electrically connected to the metal backplane via the bottom feed structure. A feeding through hole is provided on the microstrip dielectric composite board, which passes through the microstrip dielectric composite board and the bottom feed structure in sequence, and the dual-rotation feeding network is used to be electrically connected to the microwave connector in the feeding through hole; The dual-rotational feeding network includes a first rotational feeding network and a second rotational feeding network respectively connected to the broadband antenna unit, the first rotational feeding network being located on a surface of the first dielectric plate facing away from the second dielectric plate, and the second rotational feeding network being located on a surface of the second dielectric plate facing away from the first dielectric plate; The bottom-feed structure comprises two, and the feeding through holes corresponding to the two bottom-feed structures correspond one-to-one to the first rotational feeding network and the second rotational feeding network respectively; The first rotational feeding network is led out to the surface of the second dielectric plate facing away from the first dielectric plate through a transfer through-hole penetrating the microstrip dielectric composite plate, and the first rotational feeding network and the second rotational feeding network are electrically connected to the microwave connector through the corresponding feeding through-holes respectively; The broadband antenna unit includes a first metal patch and a broadband branch line coupler. The first metal patch is located on the surface of the second dielectric plate facing away from the first dielectric plate. The broadband branch line coupler is located on the surface of the first dielectric plate facing away from the second dielectric plate. The first metal patch is connected to the broadband branch line coupler via a connecting through hole passing through the microstrip dielectric composite plate. The broadband branch line coupler is connected to the dual-rotational feeding network.

2. The broadband dual circularly polarized microstrip array antenna according to claim 1, wherein: The broadband dual circularly polarized microstrip array antenna further includes a support member, which is supported by the metal back plate and the first dielectric plate.

3. The broadband dual circularly polarized microstrip array antenna according to claim 2, wherein: The support member includes a plurality of step structures fixed to the metal back plate and distributed along the periphery of the metal back plate, with two adjacent step structures spaced apart, and the first dielectric plate overlaps the table tops of the step structures.

4. The broadband dual circularly polarized microstrip array antenna according to claim 2, wherein: The support member further includes a plurality of pillars supported on the first dielectric plate and the metal back plate, and the plurality of pillars are evenly distributed in the back cavity.

5. The broadband dual circularly polarized microstrip array antenna according to claim 1, wherein: The microstrip dielectric plate assembly also includes a third dielectric plate opposite to and spaced apart from the second dielectric plate to form a cavity between the third dielectric plate and the second dielectric plate. The broadband antenna unit also includes a second metal patch located on the third dielectric plate near the surface of the second dielectric plate, and the second metal patch corresponds to the first metal patch.

6. The broadband dual circularly polarized microstrip array antenna according to claim 1, wherein: The broadband dual circularly polarized microstrip array antenna includes a plurality of broadband antenna units arranged in a rectangular array, and four adjacent broadband antenna units are rotated sequentially to form a group of antenna subarrays.

7. A communication terminal, characterized in that: It comprises the broadband dual circularly polarized microstrip array antenna according to any one of claims 1 to 6.

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