A wide-angle low-axis ratio four-feed dual circular polarization antenna unit and dual circular polarization antenna

Abstract

The invention discloses a wide-angle low-axis ratio four-feed dual circular polarization antenna unit and a dual circular polarization antenna. The antenna unit includes an equivalent shielding cavity structure and a guide layer, a radiation layer, a feed network layer, a power layer, a control layer, and a surface radio frequency interconnection function layer stacked in sequence from top to bottom; wherein the radiation layer includes four monopole radiation plates that are symmetrically distributed with a 90-degree interval and a central rotation; the feed network layer includes a double-layer feeding structure, which uses a power divider and a 3dB bridge to form left-handed and right-handed circular polarization, and realizes a four-feed dual circular polarization feeding network; the equivalent shielding cavity structure includes a first equivalent shielding cavity, a second equivalent shielding cavity, and a feed-like coaxial; the first equivalent shielding cavity is used to realize antenna shielding; the second equivalent shielding cavity is used to realize feed network shielding; the feed-like coaxial is used to realize the interconnection between the feed network and the radio frequency chip. The antenna unit has a low axis ratio index characteristic, and realizes the wide-angle scanning polarization isolation index characteristic within the working frequency band.

Description

Technical Field

[0001] The invention belongs to the technical field of antennas, and in particular relates to a wide-angle, low-axis ratio, four-feed dual circular polarization antenna unit and a dual circular polarization antenna. Background Art

[0002] With the development of mobile communication technology, millimeter wave antennas have been widely used due to their rich spectrum resources and have become one of the important evolutionary directions. Compared with linearly polarized antennas that can only receive the same linearly polarized waves as themselves, circularly polarized antennas can receive any linearly polarized waves as well as circularly polarized waves, which can avoid polarization loss caused by polarization mismatch between the transmitting and receiving antennas. Circularly polarized antennas have excellent performance in solving polarization mismatch, suppressing rain and fog interference, and eliminating the Faraday effect. Therefore, the research and design of circularly polarized antennas in the millimeter wave band is very important.

[0003] Compared with ordinary circularly polarized antennas, dual circularly polarized antennas can increase the channel capacity of wireless communication links. However, due to the high difficulty of design and implementation, there is relatively little research on millimeter-wave planar dual circularly polarized antennas. In particular, when the antenna units form an array, multi-channel RF chips are required to provide the power amplitude and phase required for synthesized beam scanning for each antenna unit in the millimeter-wave phased array, and the dual circularly polarized feed circuit needs to consider hybrid integration with power supply and control signals.

[0004] For dual circularly polarized antennas, the axial ratio index is crucial. Radiating units with excellent axial ratio index and large bandwidth can significantly improve the synthetic beam scanning characteristics of array antennas. However, most of the existing dual circularly polarized antennas mainly use a two-point asymmetric feeding method, with poor antenna axial ratio and limited axial ratio bandwidth, which cannot meet the needs of wide-angle scanning phased array antennas. At the same time, due to the asymmetry of the feeding point, the deflection problem of the main lobe pattern is also introduced. Summary of the invention

[0005] In order to solve the problems of poor axial ratio and limited axial ratio bandwidth of existing dual circular polarization antennas, the present invention provides a wide-angle low axial ratio four-feed dual circular polarization antenna unit and a dual circular polarization antenna. The technical problem to be solved by the present invention is achieved by the following technical solutions:

[0006] In the first aspect, the present invention proposes a wide-angle, low-axis ratio, four-feed, dual-circularly polarized antenna unit, comprising an equivalent shielding cavity structure and a guide layer, a radiation layer, a feed network layer, a power supply layer, a control layer, and a surface radio frequency interconnection functional layer stacked in sequence from top to bottom; wherein,

[0007] The guiding layer includes a first dielectric substrate; a circular guiding patch is provided on the upper surface of the first dielectric substrate;

[0008] The radiation layer includes a second dielectric substrate; four identical monopole radiation plates are arranged on the upper surface of the second dielectric substrate; the four monopole radiation plates are symmetrically distributed with a 90-degree interval and the center of symmetry is located directly below the center of the circular guide patch; an antenna metal bottom plate is arranged on the lower surface of the second dielectric substrate;

[0009] The feeding network layer includes a third dielectric substrate, a fourth dielectric substrate and a feeding network; the feeding network adopts a double-layer structure, the upper structure is located in the third dielectric substrate, and the lower structure is located in the fourth dielectric substrate; the feeding network uses a power divider and a 3dB bridge to realize left-hand circular polarization and right-hand circular polarization; and the four end output ports of the feeding network are respectively connected to the four monopole radiation plates through the feeding metal holes to form a four-feed dual circular polarization feeding network;

[0010] The equivalent shielding cavity structure includes multiple first equivalent shielding cavities, multiple second equivalent shielding cavities and two groups of feeding coaxials; multiple first equivalent shielding cavities and multiple second equivalent shielding cavities are arranged at intervals around the edges of the entire antenna unit; wherein the first equivalent shielding cavity runs through the upper surface of the first dielectric substrate to the lower surface of the surface RF interconnection functional layer to achieve shielding of the entire antenna unit and connectivity between multiple layers; the second equivalent shielding cavity runs through the upper surface of the third dielectric substrate to the lower surface of the fourth dielectric substrate to achieve shielding of the feeding network; two groups of feeding coaxials run from the feeding network layer to the lower surface of the surface RF interconnection functional layer to achieve interconnection between the feeding network and the RF chip.

[0011] In the second aspect, the present invention proposes a dual circularly polarized antenna, comprising a plurality of antenna units arranged in an array, the antenna unit comprising a wide-angle, low-axis ratio, four-feed dual circularly polarized antenna unit provided in the first aspect of the present invention, and the first equivalent shielding cavity and the second equivalent shielding cavity at the edges of two adjacent antenna units are shared.

[0012] Beneficial effects of the present invention:

[0013] The wide-angle low-axis ratio four-feed dual circularly polarized antenna unit provided by the present invention, on the one hand, designs four groups of radiating plates, and adopts a central rotation symmetric structure to realize the radiating layer, improves the axial ratio of the circularly polarized antenna, and ensures the symmetry of the array antenna pattern; at the same time, the power divider and the 3dB bridge are used to realize the four-point rotation and mirror-symmetric feeding of the left and right circularly polarized antenna units, which not only improves the axial ratio index characteristics of the dual circular polarization within the wide angle, but also avoids the deflection problem of the main lobe pattern; on the other hand, an equivalent shielding cavity integrated structure is adopted to reduce the overall size of the antenna unit, improve the mutual coupling effect between the antenna units in the array, and meet the needs of the wide-angle scanning phased array antenna array. By combining the equivalent shielding cavity design with the multi-point feeding antenna technology, the antenna unit significantly improves the axial ratio index characteristics of the circularly polarized antenna within the wide-angle frequency band, and has a high radiation efficiency, and realizes the wide-angle scanning polarization isolation index characteristics within the working frequency band.

[0014] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the three-dimensional structure of a wide-angle, low-axis ratio, four-feed dual circularly polarized antenna unit provided by an embodiment of the present invention;

[0016] Figure 2 yes Figure 1 A top view of a wide-angle, low-axis ratio, four-feed dual circularly polarized antenna unit is shown;

[0017] Figure 3 yes Figure 1 A side view of a wide-angle, low-axis ratio, four-feed dual circularly polarized antenna unit is shown;

[0018] Figure 4 is a schematic diagram of the structure of a feeding network provided by an embodiment of the present invention;

[0019] Figure 5 is a schematic diagram of the principle of a feeding network provided by an embodiment of the present invention;

[0020] Figure 6 It is a schematic diagram of the interconnection structure of the feed-type coaxial and surface radio frequency interconnection functional layer provided by an embodiment of the present invention;

[0021] Description of reference numerals:

[0022] 1-equivalent shielding cavity structure, 11-first equivalent shielding cavity, 12-second equivalent shielding cavity, 13-feeding coaxial, 13-1-inner column, 13-2-outer column;

[0023] 2-guiding layer, 21-first dielectric substrate, 22-guiding patch;

[0024] 3-radiation layer, 31-second dielectric substrate, 32-monopole radiation plate, 32-1-feed pad;

[0025] 4-feeding network layer, 41-third dielectric substrate, 42-fourth dielectric substrate, 43-feeding network, 43-1-first Wilkinson power divider, 43-2-second Wilkinson power divider, 43-3-first 3dB bridge, 43-4-second 3dB bridge, 43-5-first phase shifter, 43-6-second phase shifter, 43-7-printed resistor, 44-feeding metal hole, 45-strip line middle metal plate, 46-metal bottom plate;

[0026] 5- Power layer;

[0027] 6- Control layer;

[0028] 7-surface radio frequency interconnection functional layer, 71-BGA pad, 72-surface matching microstrip line, 73-quasi-coaxial pad. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] A first aspect of the present invention provides a wide-angle, low-axial-ratio four-feed dual circularly polarized antenna unit.

[0031] Please see the joint Figure 1-3 , Figure 1 is a schematic diagram of a three-dimensional structure of a wide-angle, low-axis ratio, four-feed dual circularly polarized antenna unit provided by an embodiment of the present invention, Figure 2 yes Figure 1 A top view of a wide-angle, low-axis ratio, four-feed dual circularly polarized antenna unit is shown. Figure 3 yes Figure 1 The wide-angle, low-axis ratio, four-fed, dual-circular polarization antenna unit provided in this embodiment specifically includes an equivalent shielding cavity structure 1 and a guide layer 2, a radiation layer 3, a feed network layer 4, a power supply layer 5, a control layer 6, and a surface RF interconnection function layer 7 stacked in sequence from top to bottom; wherein,

[0032] The guiding layer 2 includes a first dielectric substrate 21; a circular guiding patch 22 is provided on the upper surface of the first dielectric substrate 21;

[0033] The radiation layer 3 includes a second dielectric substrate 31; four identical monopole radiation plates 32 are provided on the upper surface of the second dielectric substrate 31; the four monopole radiation plates 32 are symmetrically distributed with a 90-degree interval and the center of symmetry is located directly below the center of the circular guide patch 22; an antenna metal plate (not shown in the figure) is provided on the lower surface of the second dielectric substrate 31;

[0034] The feeding network layer 4 includes a third dielectric substrate 41, a fourth dielectric substrate 42 and a feeding network 43; the feeding network 43 adopts a double-layer structure, the upper structure is located in the third dielectric substrate 41, and the lower structure is located in the fourth dielectric substrate 42; the feeding network 43 uses a power divider and a 3dB bridge to achieve left-hand circular polarization and right-hand circular polarization; and the four end output ports of the feeding network 43 are respectively connected to the four monopole radiation plates 32 through the feeding metal holes 44 to form a four-feed dual circular polarization feeding network;

[0035] The equivalent shielding cavity structure 1 includes a plurality of first equivalent shielding cavities 11, a plurality of second equivalent shielding cavities 12 and two groups of feeding coaxial cables 13; the plurality of first equivalent shielding cavities 11 and the plurality of second equivalent shielding cavities 12 are arranged at intervals around the edges of the entire antenna unit; wherein the first equivalent shielding cavity 11 penetrates from the upper surface of the first dielectric substrate 21 to the lower surface of the surface RF interconnection functional layer 7 to achieve shielding of the entire antenna unit and connectivity between multiple layers; the second equivalent shielding cavity 12 penetrates from the upper surface of the third dielectric substrate 41 to the lower surface of the fourth dielectric substrate 42 to achieve shielding of the feeding network 43; the two groups of feeding coaxial cables 13 penetrate from the feeding network layer 4 to the lower surface of the surface RF interconnection functional layer 7 to achieve interconnection between the feeding network 43 and the RF chip.

[0036] In this embodiment, the guiding layer 2, the radiating layer 3, the feeding network layer 4, the power layer 5, the control layer 6 and the surface radio frequency interconnection functional layer 7 are all formed by a multi-layer laminated PCB board as a substrate.

[0037] Specifically, in the guiding layer 2 , the circular guiding patch 22 is located at the center of the first dielectric substrate 21 .

[0038] Optionally, in the radiation layer 3, the monopole radiation piece 32 adopts a rectangular structure and is interconnected with the circular guide patch 22 through coupling. Each monopole radiation piece 32 is provided with a feeding pad 32-1 at the vertex of the rectangle away from the symmetry center; the four end output ports of the feeding network 43 are respectively connected to the feeding pads 32-1 of the four monopole radiation pieces 32 through the feeding metal holes 44, and the feeding metal holes 44 are not in contact with the antenna metal plate. Among them, the feeding pad 32-1 generally adopts a circular structure.

[0039] The wide-angle, low-axis-ratio four-feed dual circularly polarized antenna unit provided by the present invention is designed with four groups of radiating plates, and a central rotationally symmetrical structure is adopted to realize the radiating layer, thereby improving the axial ratio of the circularly polarized antenna and ensuring the symmetry of the array antenna pattern.

[0040] For further information, see Figure 4 , Figure 4 : is a schematic diagram of the structure of the feeding network provided by an embodiment of the present invention. The feeding network 43 designed in this embodiment adopts a double-layer feeding structure to simultaneously realize four-feed clockwise and counterclockwise 90-degree equal differences, specifically including: a first Wilkinson power divider 43-1, a second Wilkinson power divider 43-2, a first 3dB bridge 43-3, a second 3dB bridge 43-4, a first phase shifter 43-5 and a second phase shifter 43-6; and the first 3dB bridge 43-3 and the second 3dB bridge 43-4 are both 90-degree bridges, and the first phase shifter 43-5 and the second phase shifter 43-6 are both 180-degree fixed phase shifters; wherein,

[0041] The first Wilkinson power divider 43-1 is arranged in the fourth dielectric substrate 42, and has an input port and two output ports; wherein the input port of the first Wilkinson power divider 43-1 serves as a left-handed circularly polarized input port of the feeding network 43, is connected to the surface RF interconnection functional layer 7 through a group of feeding coaxials 13, one output port is connected to the first 3dB bridge 43-3, and the other output port is connected to the second 3dB bridge 43-4 through the first phase shifter 43-5, so as to realize left-handed circularly polarized feeding;

[0042] The second Wilkinson power divider 43-2 is arranged in the third dielectric substrate 41 and has one input port and two output ports; wherein the input port of the second Wilkinson power divider 43-2 serves as the right-hand circular polarization input port of the feeding network 43, is connected to the surface RF interconnection functional layer 7 through another group of feeding coaxial 13, one output port is connected to the second 3dB bridge 43-4, and the other output port is connected to the first 3dB bridge 43-3 through the second phase shifter 43-6 to realize right-hand circular polarization feeding;

[0043] The four output feed ports of the first 3dB bridge 43 - 3 and the second 3dB bridge 43 - 4 serve as four terminal output ports of the feeding network 43 , and the phases of the four output feed ports differ by 90 degrees in a counterclockwise direction.

[0044] In this embodiment, the first 3dB bridge 43-3 and the second 3dB bridge 43-4 are both formed by folding strip lines, the folded upper structure is located in the third dielectric substrate 41, the lower structure is located in the fourth dielectric substrate 42, and the folded parts are vertically interconnected through vias.

[0045] In addition, please continue to see Figure 4Printed resistors 43 - 7 are integrated at the two output ports of the first Wilkinson power divider 43 - 1 and the two output ports of the second Wilkinson power divider 43 - 2 .

[0046] It should be noted that a strip line intermediate metal plate 45 is provided between the third dielectric substrate 41 and the fourth dielectric substrate 42, that is, in the middle of the feed network 43, to provide a ground for the microstrip line;

[0047] The upper surface of the third dielectric substrate 41 and the lower surface of the second dielectric substrate 31 share the antenna metal plate;

[0048] A metal bottom plate 46 is further provided on the lower surface of the fourth dielectric substrate 42 .

[0049] It is understandable that when the feed metal hole 44 is used to realize the vertical interconnection between the end port of the feed network 43 and the four feed pads 32-1, the feed metal hole 44 and the antenna metal plate are electrically interconnected and avoided through the slot. At the same time, the folded parts of the first 3dB bridge 43-3 and the second 3dB bridge 43-4 avoid the strip line middle metal plate 45 through the opening when interconnecting.

[0050] The principle of the feeding network designed in this embodiment is described in detail below.

[0051] See also Figure 5 , Figure 5 Schematic diagram of the principle of the feeding network provided by the embodiment of the present invention. This embodiment mainly realizes dual circular polarization through two Wilkinson power dividers and two 3dB bridges. Among them, the left-hand circular polarization is fed into the electromagnetic field energy through a group of feeding coaxial 13 penetrating from the bottom of the surface RF interconnection functional layer 7 to the first Wilkinson power divider 43-1 of the feeding network 43. The power is divided into two paths by the first Wilkinson power divider 43-1, one of which is directly fed into port 1 of the first 3dB bridge 43-3, and two paths of electromagnetic energy with equal power and a phase difference of 90 degrees are output at ports 3 and 4 of the first 3dB bridge 43-3; the other output of the first Wilkinson power divider 43-1 is fed into port 1 of the second 3dB bridge 43-4 after being phase-shifted by 180 degrees by the first phase shifter 43-5, and two paths of electromagnetic energy with equal power and a phase difference of 90 degrees are output at ports 3 and 4 of the second 3dB bridge 43-4, thereby ports 3 and 4 of the first 3dB bridge 43-3 and ports 3 and 4 of the second 3dB bridge 43-4 are respectively 90 degrees apart, forming a left-hand circularly polarized four-port energy feed source.

[0052] Further, the right-hand circular polarization is fed into the electromagnetic field energy from the bottom of the surface RF interconnection functional layer 7 to the second Wilkinson power divider 43-2 of the feeding network 43 through another group of feeding coaxial 13. The power is divided into two paths by the second Wilkinson power divider 43-2, one of which is directly fed into the 2nd port of the second 3dB bridge 43-4, and two paths of electromagnetic energy with equal power and a phase difference of -90 degrees are output at the 3rd and 4th ports of the second 3dB bridge 43-4; the other output of the second Wilkinson power divider 43-2 is fed into the 2nd port of the first 3dB bridge 43-3 after being phase-shifted by 180 degrees by the second phase shifter 43-6, and two paths of electromagnetic energy with equal power and a phase difference of 90 degrees are output at the 3rd and 4th ports of the first 3dB bridge 43-3.

[0053] Therefore, the 3rd and 4th ports of the first 3dB bridge 43-3 and the 3rd and 4th ports of the second 3dB bridge 43-4 are respectively different by -90 degrees, forming a right-hand circularly polarized four-port energy feed source.

[0054] The present invention utilizes a Wilkinson power divider and a 3dB bridge to realize four-point rotation and mirror-symmetric feeding of left-hand and right-hand circularly polarized antenna units, which not only improves the axial ratio index characteristics of dual circular polarization within a wide angle, but also avoids the deflection problem of the main lobe pattern.

[0055] Furthermore, for the above two groups of feeding coaxial structures 13, the present embodiment adopts the same structural design, both of which include an inner column 13-1 and a plurality of outer columns 13-2; the plurality of outer columns 13-2 are evenly distributed around the center of the inner column 13-1; wherein,

[0056] The lower ends of the inner columns 13-1 of the two groups of feeding coaxial cables 13 are connected to the surface RF interconnection functional layer 7, and the upper ends penetrate the feeding network layer 4 and are respectively connected to the left-hand circular polarization input port and the right-hand circular polarization input port of the feeding network 43;

[0057] The lower ends of several outer columns 13-2 of the two groups of feed coaxial cables 13 are connected to the surface RF interconnection functional layer 7, and the upper ends penetrate the feed network layer 4, wherein the upper ends of several outer columns 13-2 of the first group of feed coaxial cables 13 are connected to the metal bottom plate 46 on the lower surface of the fourth dielectric substrate 42; the upper ends of several outer columns 13-2 of the second group of feed coaxial cables 13 are connected to the strip line middle metal plate 45.

[0058] Optionally, as an implementation method, this embodiment designs a quasi-coaxial structure in which four outer columns surround one inner column. Figure 6 , Figure 6Schematic diagram of the interconnection structure of the feed quasi-coaxial and surface RF interconnection functional layer provided in an embodiment of the present invention. The surface RF interconnection functional layer 7 includes a seventh dielectric substrate, and the lower surface of the seventh dielectric substrate is provided with two groups of BGA (Ball Grid Array, ball grid array packaging) pads 71, two groups of surface matching microstrip lines 72 and two groups of quasi-coaxial pads 73;

[0059] Two groups of BGA pads 71 ​​are connected to the RF chip via a multifunctional chip surface mount;

[0060] One end of the two sets of surface matching microstrip lines 72 is correspondingly connected to the lower ends of the inner columns 13 - 1 of the two sets of feeding coaxials 13 , and the other ends of the two sets of surface matching microstrip lines 72 are correspondingly connected to the two sets of BGA pads 71 ​​;

[0061] The two groups of quasi-coaxial pads 73 are connected to the lower ends of the outer columns 13 - 2 of the two groups of feeding quasi-coaxial pads 13 .

[0062] The feeding coaxial structure designed in this embodiment can ensure that the amplitude and phase multifunctional receiving and transmitting radio frequency signals are input / output to the feeding network 43 in a low impedance manner.

[0063] It can be understood that, in this embodiment, the power layer 5 includes a fifth dielectric substrate, and the control layer 6 includes a sixth dielectric substrate;

[0064] A power line is provided in the middle of the fifth dielectric substrate, and the power line penetrates from the fifth dielectric substrate to the surface radio frequency interconnection functional layer 7 to be connected to an external power source;

[0065] A control line is provided in the middle of the sixth dielectric substrate, and the control line penetrates from the sixth dielectric substrate to the surface radio frequency interconnection functional layer 7 to be connected to an external control terminal;

[0066] The lower surfaces of the fifth dielectric substrate and the sixth dielectric substrate are both provided with metal grounding plates.

[0067] The wide-angle low-axis ratio four-fed dual circularly polarized antenna unit provided by the present invention, on the one hand, designs four groups of radiating plates, and adopts a central rotation symmetric structure to realize the radiation layer, improves the axial ratio of the circularly polarized antenna, and ensures the symmetry of the array antenna pattern; at the same time, the Wilkinson power divider and the 3dB bridge are used to realize the four-point rotation and mirror-symmetric feeding of the left and right circularly polarized antenna units, which not only improves the axial ratio index characteristics of the dual circular polarization within the wide angle, but also avoids the deflection problem of the main lobe pattern; on the other hand, an equivalent shielding cavity integrated structure is adopted to reduce the overall size of the antenna unit, improve the mutual coupling effect between the antenna units in the array, and meet the needs of the wide-angle scanning phased array antenna array. By combining the equivalent shielding cavity design with the multi-point feeding antenna technology, the antenna unit significantly improves the axial ratio index characteristics of the circularly polarized antenna within the wide-angle frequency band, and has a high radiation efficiency, and realizes the wide-angle scanning polarization isolation index characteristics within the working frequency band.

[0068] In addition, in order to verify the beneficial effects of the present invention, this embodiment also simulates the S11 parameters of the wide-angle, low-axis ratio four-fed dual circularly polarized antenna unit designed by the present invention. In the specific simulation experiment, the axis ratios of left-handed and right-handed circular polarizations at intervals of 0.75 GHz from 14 GHz to 17 GHz were simulated respectively. The results show that within the range of ±60°, the axis ratios of both circular polarizations are better than 1.5, providing a good unit axis ratio basis for array broadband scanning.

[0069] The second aspect of the present invention also provides a dual circularly polarized antenna, which includes a plurality of antenna units arranged in an array. The antenna unit includes a wide-angle, low-axis ratio, four-feed dual circularly polarized antenna unit provided by the first aspect of the present invention, and the first equivalent shielding cavity and the second equivalent shielding cavity at the edges of two adjacent antenna units are shared.

[0070] Therefore, the antenna unit also has a lower axial ratio index and higher radiation efficiency, which can meet the needs of wide-angle scanning phased array antennas.

[0071] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0072] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0073] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0074] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0075] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.

Claims

1. A wide-angle, low-axis ratio, four-feed dual circularly polarized antenna unit, characterized in that: It includes an equivalent shielding cavity structure and a guide layer, a radiation layer, a feed network layer, a power supply layer, a control layer, and a surface RF interconnection functional layer stacked in sequence from top to bottom; among which, The guiding layer comprises a first dielectric substrate; a circular guiding patch is provided on the upper surface of the first dielectric substrate; The radiation layer includes a second dielectric substrate; four identical monopole radiation plates are arranged on the upper surface of the second dielectric substrate; the four monopole radiation plates are symmetrically distributed with a 90-degree interval and the center of symmetry is located directly below the center of the circular guide patch; an antenna metal plate is arranged on the lower surface of the second dielectric substrate; each of the monopole radiation plates adopts a rectangular structure; and a feeding pad is arranged at the vertex of the rectangle away from the center of symmetry of each monopole radiation plate; the four terminal output ports of the feeding network are respectively connected to the feeding pads of the four monopole radiation plates through feeding metal holes, and the feeding metal holes are not in contact with the antenna metal plate; The feeding network layer includes a third dielectric substrate, a fourth dielectric substrate and a feeding network; the feeding network adopts a double-layer structure, the upper structure is located in the third dielectric substrate, and the lower structure is located in the fourth dielectric substrate; the feeding network uses a power divider and a 3dB bridge to achieve left-hand circular polarization and right-hand circular polarization; and the four end output ports of the feeding network are respectively connected to the four monopole radiation plates through feeding metal holes to form a four-feed dual circular polarization feeding network; The feed network layer specifically includes a first Wilkinson power divider, a second Wilkinson power divider, a first 3dB bridge, a second 3dB bridge, a first phase shifter and a second phase shifter; and the first 3dB bridge and the second 3dB bridge are both 90-degree bridges, and the first phase shifter and the second phase shifter are both 180-degree fixed phase shifters; wherein, The first Wilkinson power divider is arranged in the fourth dielectric substrate and has one input port and two output ports; wherein the input port of the first Wilkinson power divider serves as a left-hand circularly polarized input port of the feeding network, is connected to the surface RF interconnection functional layer through a group of the feeding coaxials, one output port is connected to the first 3dB bridge, and the other output port is connected to the second 3dB bridge through the first phase shifter to realize left-hand circularly polarized feeding; The second Wilkinson power divider is arranged in the third dielectric substrate and has an input port and two output ports; wherein the input port of the second Wilkinson power divider serves as a right-hand circularly polarized input port of the feeding network, is connected to the surface RF interconnection functional layer through another group of the feeding coaxials, one output port is connected to the second 3dB bridge, and the other output port is connected to the first 3dB bridge through the second phase shifter to realize right-hand circularly polarized feeding; The four output feed ports of the first 3dB bridge and the second 3dB bridge serve as four terminal output ports of the feeding network, and the phases of the four output feed ports differ by 90 degrees counterclockwise; The first 3dB bridge and the second 3dB bridge are both formed by folding strip lines, the folded upper structure is located in the third dielectric substrate, the lower structure is located in the fourth dielectric substrate, and the folded parts are vertically interconnected through vias; The equivalent shielding cavity structure includes multiple first equivalent shielding cavities, multiple second equivalent shielding cavities and two groups of feeding coaxials; multiple first equivalent shielding cavities and multiple second equivalent shielding cavities are arranged at intervals around the edges of the entire antenna unit; wherein, the first equivalent shielding cavity runs through the upper surface of the first dielectric substrate to the lower surface of the surface RF interconnection functional layer to achieve shielding of the entire antenna unit and connectivity between multiple layers; the second equivalent shielding cavity runs through the upper surface of the third dielectric substrate to the lower surface of the fourth dielectric substrate to achieve shielding of the feeding network; two groups of feeding coaxials run through the feeding network layer to the lower surface of the surface RF interconnection functional layer to achieve interconnection between the feeding network and the RF chip.

2. A wide-angle, low-axis ratio, four-feed dual circularly polarized antenna unit according to claim 1, characterized in that: Printed resistors are integrated at the two output ports of the first Wilkinson power divider and the two output ports of the second Wilkinson power divider.

3. A wide-angle, low-axis ratio, four-fed, dual circularly polarized antenna unit according to claim 1, characterized in that: A stripline intermediate metal plate is also provided between the third dielectric substrate and the fourth dielectric substrate; The upper surface of the third dielectric substrate and the lower surface of the second dielectric substrate share the antenna metal plate; A metal bottom plate is also provided on the lower surface of the fourth dielectric substrate.

4. A wide-angle, low-axis ratio, four-fed dual circularly polarized antenna unit according to claim 3, characterized in that: The two groups of feed-type coaxials have the same structure, both comprising an inner column and a plurality of outer columns; the plurality of outer columns are evenly distributed around the center of the inner column; wherein, The lower ends of the inner columns of the two groups of the feed-like coaxial cables are connected to the surface RF interconnection functional layer, and the upper ends penetrate the feed network layer and are respectively connected to the left-hand circular polarization input port and the right-hand circular polarization input port of the feed network; The lower ends of several outer columns of the two groups of feed coaxial cables are connected to the surface RF interconnection functional layer, and the upper ends penetrate the feed network layer; wherein, the upper ends of several outer columns of the first group of feed coaxial cables are connected to the metal bottom plate on the lower surface of the fourth dielectric substrate, and the upper ends of several outer columns of the second group of feed coaxial cables are connected to the middle metal plate of the strip line.

5. A wide-angle, low-axis ratio, four-fed, dual circularly polarized antenna unit according to claim 4, characterized in that: The surface RF interconnection functional layer includes a seventh dielectric substrate, and the lower surface of the seventh dielectric substrate is provided with two groups of BGA pads, two groups of surface matching microstrip lines and two groups of quasi-coaxial pads; wherein, The two groups of BGA pads are connected to the radio frequency chip through a multifunctional chip surface mount; One end of the two groups of surface matching microstrip lines is correspondingly connected to the lower ends of the inner columns of the two groups of feed-type coaxials, and the other end of the two groups of surface matching microstrip lines is correspondingly connected to the two groups of BGA pads; The two groups of quasi-coaxial pads are correspondingly connected to the lower ends of several outer columns of the two groups of feeding quasi-coaxial.

6. A wide-angle, low-axis ratio, four-feed dual circularly polarized antenna unit according to claim 1, characterized in that: The power supply layer includes a fifth dielectric substrate, and the control layer includes a sixth dielectric substrate; A power line is provided in the middle of the fifth dielectric substrate, and the power line penetrates from the fifth dielectric substrate to the surface RF interconnection functional layer to be connected to an external power source; A control line is provided in the middle of the sixth dielectric substrate, and the control line penetrates from the sixth dielectric substrate to the surface radio frequency interconnection functional layer to be connected to an external control terminal; The lower surfaces of the fifth dielectric substrate and the sixth dielectric substrate are both provided with metal grounding plates.

7. A dual circular polarization antenna, comprising a plurality of antenna units arranged in an array, characterized in that: The antenna unit comprises a wide-angle, low-axis ratio, four-feed, dual-circularly polarized antenna unit as described in any one of claims 1 to 6, and a first equivalent shielding cavity and a second equivalent shielding cavity at the edges of two adjacent antenna units are shared.

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