Dual-frequency common-aperture antenna radiation element and dual-frequency common-aperture antenna

Abstract

The present application provides a dual-band common-aperture antenna radiation element and a dual-band common-aperture antenna, which relate to communication and antenna technologies. Each radiation element includes a K-band folded dipole, four Ka-band microstrip patches, and two groups of feed baluns with an orthogonal layout. The Ka-band microstrip patches are coupled to the feed network layer through two orthogonally arranged H-shaped Ka-band coupling slots. The orthogonal feed balun is used to achieve the option of K-band dual linear polarization, left-handed circular polarization or right-handed circular polarization, and the orthogonal H-shaped slot is used to achieve the option of Ka-band dual linear polarization, left-handed circular polarization or right-handed circular polarization. The dual-band common-aperture antenna includes an antenna layer, a feed network layer, a strip line and a waveguide transition layer. The antenna layer includes radiation elements arranged in a periodic array. By means of technologies such as bridging and vertical conductive vias, a high-density feed network layout is achieved while reducing the number of PCB layers, effectively realizing the common-aperture design of the K-band / Ka-band and the multi-polarization application with polarization options.

Description

Technical Field

[0001] This application belongs to the field of communication technologies, relates to a dual-band common-aperture antenna, and particularly relates to a dual-band common-aperture antenna radiation element and a dual-band common-aperture antenna. Background Art

[0002] Dual-band common-aperture antennas are widely used in modern communication systems, especially in full-duplex communications such as satellite communications and mobile communications. It is a widely adopted method to effectively reduce the number of antennas, improve the system integration degree, and reduce the antenna cost.

[0003] Common methods to achieve dual-band common-aperture include using the same broadband radiation element or aperture, such as parabolic antennas, waveguide horn arrays, etc.

[0004] Although the broadband radiation element or aperture solves the problem of common-aperture, it often brings deterioration of other performances. For example, a dual-band parabolic antenna requires a complex dual-feed structure and cannot achieve optimal efficiency in both operating frequency bands, and some performances need to be sacrificed. In addition, the dual-band parabolic structure is heavy, has a high profile, and has high requirements for the platform. For example, the waveguide horn array is limited by the element spacing, and grating lobes are extremely likely to be generated in the high-frequency band, resulting in greatly deteriorated performance and seriously interfering with communications in other directions.

[0005] Other dual-band common-aperture methods include stacked design, staggered layout, etc., where radiation elements of different frequency bands are arranged in the same physical aperture. The challenge faced by this type of design is how to achieve high isolation in the same physical aperture and reduce the mutual interference of performances between the two frequency bands. And achieving polarization-selectable design is also a very severe challenge for the layout of the feeding network.

[0006] Currently, dual-band common-aperture antennas adopting the stacked design and staggered layout schemes mainly focus on the low-frequency band, such as the L band; while there are fewer executable schemes in the high-frequency band, such as the K band and Ka band.

[0007] Generally speaking, dual-band parabolic antennas and waveguide horn arrays perform poorly in the K band / Ka band, while dual-band common-aperture antennas adopting the stacked design and staggered layout schemes face many challenges in aspects such as multi-polarization and high-frequency band applications. Summary of the Invention

[0008] Aiming at problems such as easy mutual interference of the radiation performances of K / Ka dual-band common-aperture antennas, difficult layout of the feeding network, and great difficulty in achieving multi-polarization, this application provides a dual-band common-aperture antenna radiation element and a dual-band common-aperture antenna, effectively realizing the K / Ka dual-band common-aperture design and polarization-selectable multi-polarization applications, and providing a compact K / Ka dual-band common-aperture satellite terminal antenna solution with a low profile, broadband, and high aperture efficiency for satellite communications.

[0009] To achieve the above object, the present invention adopts the following technologies:

[0010] A dual-frequency common-aperture antenna radiation unit is arranged in a periodic array on the antenna layer of the antenna. Each radiation unit includes:

[0011] A K-band folded dipole located on the top surface of the antenna layer;

[0012] Four Ka-band microstrip patches located in the middle interlayer of the antenna layer and evenly distributed around the K-band folded dipole; and

[0013] Two groups of feeding baluns arranged orthogonally and located in the middle interlayer of the antenna layer. The feeding baluns are connected to the K-band folded dipole through conductive vias;

[0014] The feeding baluns are coupled to the feeding network layer below the antenna layer through H-shaped K-band coupling slots. When the two groups of feeding baluns are fed with the same phase, K-band dual linear polarization is achieved. When fed with a 90° phase difference, K-band left-handed circular polarization or right-handed circular polarization is achieved;

[0015] Each Ka-band microstrip patch is coupled to the feeding network layer through two orthogonally arranged H-shaped Ka-band coupling slots. When the two H-shaped Ka-band coupling slots are fed with the same phase, Ka-band dual linear polarization is achieved. When fed with a 90° phase difference, Ka-band left-handed circular polarization or right-handed circular polarization is achieved;

[0016] The H-shaped K-band coupling slots and the H-shaped Ka-band coupling slots are located in the H-shaped coupling slot array provided on the bottom surface of the antenna layer or the top surface of the feeding network layer.

[0017] Furthermore, the K-band folded dipole has a cross-shaped ring structure, including four circularly arranged ring structures connected together to form a cross shape, and has a filtering characteristic for Ka-band electromagnetic signals.

[0018] Furthermore, each group of feeding baluns includes a feeding balun upper structure and a feeding balun lower structure. Along the height direction of the antenna layer, the feeding balun upper structure is higher than the feeding balun lower structure. One end of the feeding balun upper structure is a 180° phase feeding wire, and the other end is connected to the floor layer in the antenna layer through a grounding via. One end of the feeding balun lower structure is a 0° phase feeding wire, and the other end is coupled to the feeding network layer through an H-shaped K-band coupling slot;

[0019] Furthermore, the K-band folded dipole is connected to two 0° phase feeding wires and two 180° phase feeding wires through four conductive vias.

[0020] Further, the K-band folded dipole corresponds to two independent K-band electromagnetic transmission paths. When receiving signals, one path sequentially passes through the K-band folded dipole, a set of feed baluns, and the H-shaped K-band coupling slot, and the other path sequentially passes through the K-band folded dipole, another set of feed baluns, and the H-shaped K-band coupling slot. The path for transmitting signals is opposite to the path for receiving signals.

[0021] Further, the length direction of the annular structure is arranged at a predetermined angle with the side of the antenna layer, and the Ka-band microstrip patches are respectively located in the length direction of the annular structure.

[0022] Further, each Ka-band microstrip patch includes an upper-layer microstrip patch unit and a lower-layer microstrip patch unit arranged at intervals along the height direction of the antenna layer.

[0023] Further, a circle of grounding conductive vias are respectively arrayed around the edges of the upper-layer microstrip patch unit and the lower-layer microstrip patch unit, and the grounding conductive vias are connected to the ground plane layer in the antenna layer.

[0024] Further, each Ka-band microstrip patch corresponds to two independent Ka-band electromagnetic transmission paths. When transmitting signals, one path sequentially passes through one of the H-shaped Ka-band coupling slots, the lower-layer microstrip patch unit, and the upper-layer microstrip patch unit, and the other path sequentially passes through the other H-shaped Ka-band coupling slot, the lower-layer microstrip patch unit, and the upper-layer microstrip patch unit. The path for receiving signals is opposite to the path for transmitting signals.

[0025] A dual-band common-aperture antenna includes an antenna layer, a feed network layer, and a stripline-to-waveguide transition layer stacked from top to bottom. The antenna layer includes the dual-band common-aperture antenna radiation unit described above.

[0026] Further, the feed network layer includes a plurality of mutually isolated multi-stage H-shaped stripline feed networks. The ends of the multi-stage H-shaped stripline feed networks have electrical coupling structures for electrical coupling with the H-shaped coupling slot array provided on the bottom surface of the antenna layer or the top surface of the feed network layer to conduct signals with the antenna layer. The input / output interlayer coupling slots of the multi-stage H-shaped stripline feed networks are connected to the stripline-to-waveguide transition layer.

[0027] Further, the feed network layer includes four mutually isolated multi-stage H-shaped stripline feed networks, namely the first H-shaped feed network, the second H-shaped feed network, the third H-shaped feed network, and the fourth H-shaped feed network. The signal transmission lengths of the first H-shaped feed network and the second H-shaped feed network are the same, and they are two orthogonal polarization feed networks for the Ka band. The signal transmission lengths of the third H-shaped feed network and the fourth H-shaped feed network are the same, and they are two orthogonal polarization feed networks for the K band.

[0028] Furthermore, the feeding network layer includes two PCB layers. The first H-shaped feeding network and the third H-shaped feeding network are located on one of the PCB layers, and the second H-shaped feeding network and the fourth H-shaped feeding network are located on the other PCB layer. At the intersection of the transmission branches of different multi-stage H-shaped stripline feeding networks on the same PCB layer, a bridging structure is adopted. One of the transmission branches of the multi-stage H-shaped stripline feeding network at the intersection is disconnected, and vertical vias are respectively arranged at both ends of the disconnected part. The two vertical vias are connected to the same transmission bridge line located on the other PCB layer.

[0029] Furthermore, the stripline-to-waveguide transition layer includes a plurality of transition units. Each transition unit includes a signal transmission stripline and a coupling patch located in different interlayers. One end of the signal transmission stripline is connected and conducted with the input end / output end of the multi-stage H-shaped stripline feeding network through an interlayer coupling gap, and the other end is signal-conducted with the coupling patch through an H-shaped microstrip coupling gap.

[0030] Furthermore, among the plurality of transition units, there are at least a pair of K-band transition units and at least a pair of Ka-band transition units. A circle of first grounding holes arranged in a rectangular ring is provided on the peripheral side of the coupling patch, and the first grounding holes are connected to the ground layer in the stripline-to-waveguide transition layer. In the K-band transition unit, the rectangular area surrounded by the first grounding holes serves as a K-band input / output port. In the Ka-band transition unit, the rectangular area surrounded by the first grounding holes serves as a Ka-band input / output port.

[0031] Furthermore, second grounding holes are respectively arranged in an array on both sides of the signal transmission stripline and around the coupling patch, and the second grounding holes are connected to the ground layer in the stripline-to-waveguide transition layer.

[0032] Furthermore, the H-shaped microstrip coupling gap includes a straight section and open rectangular rings symmetrically and perpendicularly connected to both ends in the length direction of the straight section. The openings of the open rectangular rings face outward and are on the extension line of the straight section in the length direction. In the height direction of the stripline-to-waveguide transition layer, the projection of the signal transmission stripline is perpendicularly intersected with the projection of the straight section.

[0033] Furthermore, the antenna layer, the feeding network layer, and the stripline-to-waveguide transition layer are respectively implemented by multi-layer PCB boards.

[0034] The beneficial effects of the present invention are as follows:

[0035] 1. By combining a heterogeneous folded dipole and a double-layer microstrip patch and arranging them vertically and staggeredly, a co-aperture radiation unit design for K / Ka bands can be realized. By optimizing the structure of the folded dipole, the re-radiation of Ka-band electromagnetic signals on the K-band antenna can be suppressed, ensuring the performance of the Ka band. In addition, H-shaped slots are used to achieve electromagnetic coupling, reducing the processing difficulty of the PCB;

[0036] 2. Two sets of orthogonal feeding baluns are used to realize the optional dual linear polarization, left-hand circular polarization or right-hand circular polarization in the K band, and two orthogonal H-type Ka band coupling slots are used to realize the optional dual linear polarization, left-hand circular polarization or right-hand circular polarization in the Ka band, which can be adapted according to application needs. The wiring density of the single-layer feeding network and the staggered layout of the orthogonal polarization feeding network are reduced by bridging, vertical conductive vias and other technical means, so as to achieve a high-density feeding network layout while reducing the number of PCB layers. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a diagram of the overall structure of the dual-frequency common-aperture antenna of an embodiment of the present application.

[0038] Figure 2 It is a schematic diagram of the cross section of the radiation unit and the transmission path of an embodiment of the present application.

[0039] Figure 3 It is a schematic diagram of the structure of the K-band folded oscillator and the Ka-band microstrip patch in the radiation unit of the embodiment of the present application.

[0040] Figure 4 It is the antenna gain simulation result with and without the folded dipole in the embodiment of the present application.

[0041] Figure 5 It is a schematic diagram of the structure of the K-band folded oscillator and the feeding balun in the radiation unit of the embodiment of the present application.

[0042] Figure 6 It is a partial top view of the H-type coupling slot array according to an embodiment of the present application.

[0043] Figure 7 It is a top view of the feed network layer of an embodiment of the present application.

[0044] Figure 8 It is a schematic diagram of the bridging structure of an embodiment of the present application.

[0045] Figure 9 It is a schematic diagram of the structure of the switching unit of an embodiment of the present application.

[0046] Figure 10 This is a diagram of the overall structure of the dual-frequency co-aperture antenna from another perspective of an embodiment of the present application.

[0047] Figure 11 It is a simulation result diagram of the stripline and waveguide transition layer in the K band of the embodiment of the present application.

[0048] Figure 12 It is a simulation result diagram of the stripline and waveguide transition layer in the Ka band of an embodiment of the present application.

[0049] Reference numerals: 100a - antenna layer, 100b - feed network layer, 100c - stripline - waveguide transition layer, 111 - K - band folded dipole, 111a - ring structure, 112 - Ka - band microstrip patch, 112a - upper - layer microstrip patch unit, 112b - lower - layer microstrip patch unit, 113a - first Ka - band path, 113b - second Ka - band path, 114a - first K - band path, 114b - second K - band path, 121 - conductive via, 122 - feed balun, 122a - upper - layer structure of feed balun, 122b - lower - layer structure of feed balun, 122c - 180° phase feed line, 122d - 0° phase feed line, 123 - ground via, 124 - floor layer, 125 - H - type Ka - band coupling slot, 126 - H - type K - band coupling slot, 130 - H - type coupling slot array, 140 - first H - type feed network, 142 - second H - type feed network, 144 - third H - type feed network, 146 - fourth H - type feed network, 148 - electrical coupling structure, 151 - transmission branch line, 152 - vertical via, 153 - transmission bridge line, 170 - second ground hole, 171 - signal - transmission stripline, 172 - coupling patch, 173 - H - type microstrip coupling slot, 173a - straight section, 173b - open rectangular ring, 174 - first ground hole, 175 - rectangular area, 181 - K - band input / output port, 182 - Ka - band input / output port. Detailed implementation manners

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following describes the embodiments of the present invention in detail with reference to the accompanying drawings. However, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0051] In one aspect of the embodiments of the present application, a dual - frequency co - aperture antenna radiation unit is provided. As Figures 1 - 3 、 Figure 5 shown, it is arranged in a periodic array on the antenna layer 100a of the antenna. Each radiation unit includes: a K - band folded dipole 111 located on the top surface of the antenna layer 100a, four Ka - band microstrip patches 112 located in the middle sandwich layer of the antenna layer 100a and evenly distributed around the K - band folded dipole 111, and two groups of feed baluns 122 arranged orthogonally in the middle sandwich layer of the antenna layer 100a.

[0052] The feed balun 122 is connected to the K - band folded dipole 111 through the conductive via 121; and is coupled to the feed network layer 100b below the antenna layer 100a in the antenna through the H - type K - band coupling slot 126. When the feed balun 122 is fed with the same phase, K - band dual - linear polarization is achieved, and when fed with a 90° phase difference, K - band left - hand circular polarization or right - hand circular polarization is achieved.

[0053] Each Ka-band microstrip patch 112 is coupled to the feed network layer 100b through two orthogonally arranged H-shaped Ka-band coupling slots 125. When the H-shaped Ka-band coupling slots 125 are fed with the same phase, Ka-band dual linear polarization is achieved. When fed with a 90° phase difference, Ka-band left-handed circular polarization or right-handed circular polarization is achieved.

[0054] As Figure 6 shown, the H-shaped K-band coupling slot 126 and the H-shaped Ka-band coupling slot 125 are located in the H-shaped coupling slot array 130; as Figure 1 shown, the H-shaped coupling slot array 130 is located on the bottom surface of the antenna layer 100a or the top surface of the feed network layer 100b. Specifically, the dimensions, spacings, relative positions, etc. of the slots in the H-shaped coupling slot array 130 are set according to the operating frequency. Using the H-shaped coupling slot array 130 for coupling conduction can reduce the processing difficulty of the PCB layers and allow independent processing of each functional layer.

[0055] As Figure 3 and Figure 5 shown, a structural example of the K-band folded dipole 111 is a cross-shaped ring structure, including four circular ring structures 111a arranged in a circular array and connected together to form a cross shape, which can optimize the suppression of the re-radiation of Ka-band electromagnetic signals on the K-band folded dipole 111 and has a filtering characteristic for Ka-band electromagnetic signals.

[0056] The two sets of feed baluns 122 are arranged orthogonally and staggered from each other. As Figure 5 shown, the feed balun 122 adopts a stripline structure. Each set includes a feed balun upper structure 122a and a feed balun lower structure 122b. Along the height direction of the antenna layer 100a, the feed balun upper structure 122a is set higher than the feed balun lower structure 122b. One end of the feed balun upper structure 122a is a 180° phase feed line 122c, and the other end is connected to the floor layer 124 in the antenna layer 100a through a grounding via 123. One end of the feed balun lower structure 122b is a 0° phase feed line 122d, and the other end is coupled to the feed network layer 100b through the H-shaped K-band coupling slot 126; the K-band folded dipole 111 is connected to two 0° phase feed lines 122d and two 180° phase feed lines 122c through four conductive vias 121 to achieve equal-amplitude feeding of 0° and 180°. Since the feed balun upper structure 122a is set higher than the feed balun lower structure 122b, the lengths of the two conductive vias 121 connecting the feed balun upper structure 122a are different from the lengths of the two conductive vias 121 connecting the feed balun lower structure 122b, forming an upper and lower staggered layout structure.

[0057] Specifically, the lengths of the upper structure 122a and the lower structure 122b of the feeding balun are reasonably set according to the dielectric constant of the PCB layer where they are located and the operating frequency.

[0058] As Figure 2 shown, the K-band folded dipole 111 corresponds to two independent K-band electromagnetic transmission paths. When receiving signals, one path sequentially passes through the K-band folded dipole 111, a set of feeding baluns 122, and the H-shaped K-band coupling slot 126, as Figure 2 shown in the first K-band path 114a; the other path sequentially passes through the K-band folded dipole 111, another set of feeding baluns 122, and the H-shaped K-band coupling slot 126, as Figure 2 shown in the second K-band path 114b. Figure 2 Only the paths for receiving signals are shown. After the signals are received by the K-band folded dipole 111, they are transmitted through the first K-band path 114a and the second K-band path 114b respectively, corresponding to the incoming wave signals in two orthogonal polarization directions. The paths for transmitting signals are opposite to those for receiving signals.

[0059] A particularly desired radiation characteristic is that when the radiation unit in the low-frequency band is blocked, the radiation performance of the high-frequency band antenna located below does not distort or deteriorate. Such radiation performance includes, but is not limited to: axial gain, radiation pattern, axial ratio, cross-polarization isolation, etc. Combining Figure 1 and Figure 3 shown, the sides of the K-band folded dipole 111 are not parallel to the sides of the antenna layer 100a, but are arranged at a certain angle. The length direction of the ring structure 111a is arranged at a predetermined angle with the sides of the antenna layer 100a, preferably at a 45° angle. The Ka-band microstrip patches 112 are respectively located in the length direction of the ring structure 111a. Specifically, in the coordinate system as Figure 3 shown, in the XY plane, the four Ka-band microstrip patches 112 are respectively located in the four quadrants centered on the K-band folded dipole 111. Based on this structure, as Figure 4 shown, the simulation results of the Ka-band axial gain in the presence / absence of the K-band folded dipole 111 are shown. Figure 4 In , the ordinate represents the axial gain (dBi), the abscissa represents the operating frequency (GHz), the line 1002 shows the Ka-band axial gain in the absence or without the K-band folded dipole 111, and the line 1004 shows the Ka-band axial gain in the absence or without the K-band folded dipole 111. It can be seen that in the case of a common aperture, the structure and layout angle of the K-band folded dipole 111 and the position setting method of the Ka-band microstrip patches 112 adopted in this example have little impact on the Ka-band axial gain, and the entire operating frequency band is controlled below 0.4 dB.

[0060] As Figure 2 and Figure 3 shown, each Ka-band microstrip patch 112 includes an upper-layer microstrip patch unit 112a and a lower-layer microstrip patch unit 112b that are arranged at intervals along the height direction of the antenna layer 100a. The upper-layer microstrip patch unit 112a is located above the lower-layer microstrip patch unit 112b.

[0061] Preferably, a circle of grounding conductive vias are respectively arrayed around the peripheries of the upper-layer microstrip patch unit 112a and the lower-layer microstrip patch unit 112b. The grounding conductive vias are connected to the ground plane layer 124 in the antenna layer 100a to share the ground plane with the K-band folded dipole 111. Through the arrangement of the grounding conductive vias, the mutual interference between the feed balun 122 and the Ka-band microstrip patch 112 is isolated to achieve electrical isolation.

[0062] As Figure 2 shown, each Ka-band microstrip patch 112 corresponds to two independent Ka-band electromagnetic transmission paths. When transmitting signals, one path sequentially passes through one of the H-shaped Ka-band coupling slots 125, the lower-layer microstrip patch unit 112b, and the upper-layer microstrip patch unit 112a, as Figure 2 shown by the first Ka-band path 113a; the other path sequentially passes through the other H-shaped Ka-band coupling slot 125, the lower-layer microstrip patch unit 112b, and the upper-layer microstrip patch unit 112a, as Figure 2 shown by the second Ka-band path 113b. Figure 2 Only the path conditions for transmitting signals are shown. The transmitted signals are introduced through two orthogonal H-shaped Ka-band coupling slots 125 and are respectively transmitted after passing through the first Ka-band path 113a and the second Ka-band path 113b to achieve the input of two orthogonal polarized electromagnetic signals. The path for receiving signals is opposite to the path for transmitting signals.

[0063] On the other hand, an embodiment of the present application provides a dual-frequency common-aperture antenna, which is implemented by using a multi-layer PCB board structure. As Figure 1 and Figure 10 shown, it includes an antenna layer 100a, a feed network layer 100b, and a stripline-to-waveguide transition layer 100c that are stacked from top to bottom. The feed network layer 100b is arranged between the antenna layer 100a and the stripline-to-waveguide transition layer 100c. Although not shown, each layer of the antenna layer 100a, the feed network layer 100b, and the stripline-to-waveguide transition layer 100c includes one or more PCB sub-layers. Preferably, they are respectively implemented by using multi-layer PCB boards.

[0064] The antenna layer 100a, the feed network layer 100b, and the stripline-to-waveguide transition layer 100c are electrically connected through coupling slots. For example, the antenna layer 100a and the feed network layer 100b can be electrically connected through the H-shaped coupling slot array 130 located on the bottom surface of the antenna layer 100a or the top surface of the feed network layer 100b. Signal conduction and electromagnetic shielding are achieved through different vias inside each layer.

[0065] Among them, the antenna layer 100a includes the dual-band common-aperture antenna radiation units described in the previous implementation.

[0066] As an optional example, the periodic array formed by the antenna radiation units in the antenna layer 100a includes 4×4 K-band folded dipoles 111 and 8×8 Ka-band microstrip patches 112. The array of K-band folded dipoles 111 corresponds to the K-band antenna radiation array, and the array of Ka-band microstrip patches 112 corresponds to the Ka-band antenna radiation array. The period of the Ka-band antenna radiation array is half of the period of the K-band antenna radiation array. Specifically, the array scale can be conveniently adjusted and expanded according to application requirements.

[0067] As Figure 7 shown, the feed network layer 100b includes a plurality of mutually isolated multi-stage H-shaped stripline feed networks. The ends of the multi-stage H-shaped stripline feed networks have electrical coupling structures 148 for electrically coupling with the H-shaped coupling slot array 130 located on the bottom surface of the antenna layer 100a or the top surface of the feed network layer 100b to conduct signals with the antenna layer 100a. The input / output ends of the multi-stage H-shaped stripline feed networks are connected to the stripline-to-waveguide transition layer 100c through layer-to-layer coupling slots.

[0068] As a specific example, the feed network layer 100b includes four mutually isolated multi-stage H-shaped stripline feed networks, namely the first H-shaped feed network 140, the second H-shaped feed network 142, the third H-shaped feed network 144, and the fourth H-shaped feed network 146.

[0069] Among them, the signal transmission lengths of the first H-shaped feed network 140 and the second H-shaped feed network 142 are the same, and they are two orthogonal polarization feed networks for the Ka band; the signal transmission lengths of the third H-shaped feed network 144 and the fourth H-shaped feed network 146 are the same, and they are two orthogonal polarization feed networks for the K band. By setting the same signal transmission length, signal delay caused by different path lengths for each path can be avoided.

[0070] In the prior art, each feeding network in each polarization direction requires an independent PCB layer. As the number of feeding networks increases, the number of required PCB layers also increases. For example, a dual-band dual-polarization common-aperture antenna requires 4 feeding networks, so the antenna should include 4 independent feeding network PCB layers. However, the introduction of more PCB layers will cause more potential signal losses, resulting in higher costs and higher manufacturing difficulties, as well as potential alignment risks, etc. Preferably, compared with the existing method of arranging each feeding network on a single PCB layer, in this embodiment, the feeding network layer 100b can adopt a solution that only includes two PCB layers. The first H-shaped feeding network 140 and the third H-shaped feeding network 144 are located on one PCB layer, and the second H-shaped feeding network 142 and the fourth H-shaped feeding network 146 are located on the other PCB layer, thereby reducing the number of required PCB layers.

[0071] When using two PCB layers, there may be crossovers. To address this problem caused by reducing the number of PCB layers, preferably, at the crossover of the transmission branches of different multi-stage H-shaped stripline feeding networks on the same PCB layer, a bridging structure is adopted, such as Figure 8 shown. Disconnect one of the transmission branches 151 of the multi-stage H-shaped stripline feeding network at the crossover, and respectively set vertical vias 152 at both ends of the disconnection. The two vertical vias 152 are connected to the same transmission bridge line 153 located on another PCB layer, so that the transmission branch 151 of the other multi-stage H-shaped stripline feeding network can pass below or above the transmission bridge line 153 (specifically determined according to the relationship between the PCB layers where the two multi-stage H-shaped stripline feeding networks corresponding to the bridging structure at the crossover are located and the PCB layer where the transmission bridge line 153 is located). Through the bridging structure, the multi-stage H-shaped stripline feeding networks in two polarization directions are formed in a staggered layout, achieving the purpose of reducing interference between different multi-stage H-shaped stripline feeding networks on the same layer and reducing the number of PCB layers while ensuring the necessary port isolation.

[0072] As Figure 9 shown, the stripline-to-waveguide transition layer 100c includes multiple transition units. The transition unit includes a signal transmission stripline 171 and a coupling patch 172 in different interlayers. One end of the signal transmission stripline 171 is connected and conducted with the input / output end of the multi-stage H-shaped stripline feeding network through an interlayer coupling gap, and the other end is signal-conducted with the coupling patch 172 through an H-shaped microstrip coupling gap 173. The signal is transmitted along the signal transmission stripline 171 and coupled to the coupling patch 172 through the H-shaped microstrip coupling gap 173 to excite the TM of the coupling patch 172 01A broadband transition of a rectangular waveguide is implemented in this mode to achieve the connection between a stripline and a waveguide. To constrain electromagnetic signals, a first ground hole 174 arranged in a rectangular ring is provided on the peripheral side of the coupling patch 172, and the first ground hole 174 is connected to the ground layer in the stripline and waveguide transition layer 100c.

[0073] As Figure 11 and Figure 12 respectively show the simulation results of the stripline and waveguide transition layer 100c in the K band and Ka band. Among them, the ordinate represents the reflection coefficient (dB), and the abscissa represents the operating frequency (GHz). It can be seen from Figure 11 that the reflection coefficients of line 1108 in the K band are all below -15 dB. It can be seen from Figure 12 that the reflection coefficients of line 1112 in the Ka band are all below -19 dB.

[0074] Specifically, among the multiple transition units, there are at least a pair of K-band transition units and at least a pair of Ka-band transition units; in the K-band transition unit, the rectangular region 175 surrounded by the first ground hole 174 serves as a K-band input / output port 181; in the Ka-band transition unit, the rectangular region 175 surrounded by the first ground hole 174 serves as a Ka-band input / output port 182.

[0075] Specifically, in the example shown in Figure 10 , there is a pair of K-band transition units, corresponding to a pair of K-band input / output ports 181; there are two pairs of Ka-band transition units, corresponding to two pairs of Ka-band input / output ports 182. The rectangular waveguide feeds the antenna through these ports. When a pair of K-band input / output ports 181 are fed with equal phases, the K-band antenna generates two orthogonal linearly polarized waves; when fed with a +90° or -90° phase difference, the K-band antenna generates a left-handed circularly polarized or right-handed circularly polarized wave. Similarly, when a pair of Ka-band input / output ports 182 are fed with equal phases, the Ka-band antenna generates two orthogonal linearly polarized waves; when fed with a +90° or -90° phase difference, the Ka-band antenna generates a left-handed circularly polarized or right-handed circularly polarized wave.

[0076] Preferably, second ground holes 170 are respectively arranged in an array on both sides of the signal transmission stripline 171 and the periphery of the coupling patch 172. The second ground holes 170 are connected to the ground layer in the stripline and waveguide transition layer 100c, and functions such as electromagnetic shielding, interference reduction, impedance matching optimization, and signal integrity improvement can be achieved.

[0077] Specifically, as Figure 9In the illustrated example, a specific structure of the H-shaped microstrip coupled slot 173 includes a straight section 173a and open rectangular loops 173b symmetrically and perpendicularly connected to both ends of the straight section 173a in the length direction. The openings of the open rectangular loops 173b face outward and are on the extension line of the straight section 173a in the length direction. By setting such a structure, the bandwidth of the coupled slot can be effectively increased to achieve the coupling of broadband signals.

[0078] In the height direction of the stripline and waveguide transition layer 100c, the projection of the signal transmission stripline 171 intersects perpendicularly with the projection of the straight section 173a to achieve the feeding of the straight section 173a and the open rectangular loops 173b.

[0079] The above are only the preferred embodiments of the present application and are not used to limit the present application. Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application.

Claims

1. A dual-frequency common aperture antenna radiating unit, characterized in that: The radiation units are arranged in a periodic array on an antenna layer (100a) of the antenna, and each radiation unit comprises: A K-band folded oscillator (111) located on the top surface of the antenna layer (100a); Four Ka-band microstrip patches (112) located in the middle interlayer of the antenna layer (100a) and evenly distributed around the K-band folded oscillator (111); and Two groups of feeding baluns (122) arranged in an orthogonal manner and located in the middle layer of the antenna layer (100a), the feeding baluns (122) being connected to the K-band folded oscillator (111) through conductive vias (121); The feeding balun (122) is coupled with a feeding network layer (100b) located below the antenna layer (100a) in the antenna through an H-shaped K-band coupling slot (126); when two groups of feeding baluns (122) are fed with the same phase, K-band dual linear polarization is achieved; and when 90° phase difference feeding is used, K-band left-hand circular polarization or right-hand circular polarization is achieved; Each Ka-band microstrip patch (112) is coupled to a feeding network layer (100b) via two orthogonally arranged H-type Ka-band coupling slots (125); when the two H-type Ka-band coupling slots (125) are fed with the same phase, Ka-band dual linear polarization is achieved; and when 90° phase difference feeding is used, Ka-band left-hand circular polarization or right-hand circular polarization is achieved; The H-type K-band coupling slot (126) and the H-type Ka-band coupling slot (125) are located in an H-type coupling slot array (130) arranged on the bottom surface of the antenna layer (100a) or the top surface of the feed network layer (100b); The K-band folded oscillator (111) is in a cross-shaped annular structure, comprising four annular structures (111a) in a circular array and connected together to form a cross shape, the length direction of the annular structure (111a) being arranged at a predetermined angle with the side of the antenna layer (100a), and the Ka-band microstrip patches (112) are respectively located in the length direction of the annular structure (111a).

2. The dual-frequency common-aperture antenna radiation unit according to claim 1, characterized in that: Each group of feeding baluns (122) includes a feeding balun upper structure (122a) and a feeding balun lower structure (122b); one end of the feeding balun upper structure (122a) is a 180° phase feeding line (122c), and the other end is connected to the floor layer (124) in the antenna layer (100a) through a ground via (123); one end of the feeding balun lower structure (122b) is a 0° phase feeding line (122d), and the other end is coupled to the feeding network layer (100b) through an H-type K-band coupling slot (126); The K-band folded oscillator (111) is connected to two 0° phase feed lines (122d) and two 180° phase feed lines (122c) through four conductive vias (121).

3. The dual-frequency common-aperture antenna radiation unit according to claim 1, characterized in that: The K-band folded oscillator (111) corresponds to two independent K-band electromagnetic transmission paths. When used for receiving signals, one of the paths passes through the K-band folded oscillator (111), a group of feeding baluns (122), and an H-type K-band coupling slot (126) in sequence, and the other path passes through the K-band folded oscillator (111), another group of feeding baluns (122), and an H-type K-band coupling slot (126) in sequence. The path used for transmitting signals is opposite to the path used for receiving signals.

4. The dual-frequency common-aperture antenna radiation unit according to claim 1, characterized in that: Each Ka-band microstrip patch (112) comprises an upper microstrip patch unit (112a) and a lower microstrip patch unit (112b) which are arranged at intervals along the layer height direction of the antenna layer (100a).

5. The dual-frequency common-aperture antenna radiation unit according to claim 4, characterized in that: A circle of grounding conductive holes is arrayed on the periphery of the edges of the upper microstrip patch unit (112a) and the lower microstrip patch unit (112b), and the grounding conductive holes are connected to the floor layer (124) in the antenna layer (100a).

6. The dual-frequency common-aperture antenna radiation unit according to claim 4, characterized in that: Each Ka-band microstrip patch (112) corresponds to two independent Ka-band electromagnetic transmission paths. When used to transmit signals, one of the paths passes through one of the H-type Ka-band coupling slots (125), a lower microstrip patch unit (112b), and an upper microstrip patch unit (112a) in sequence, and the other path passes through another H-type Ka-band coupling slot (125), a lower microstrip patch unit (112b), and an upper microstrip patch unit (112a) in sequence. The path used for receiving signals is opposite to the path used for transmitting signals.

7. A dual-frequency common aperture antenna, characterized in that: It comprises an antenna layer (100a), a feed network layer (100b), and a stripline and waveguide transition layer (100c) stacked from top to bottom, wherein the antenna layer (100a) comprises a dual-frequency co-aperture antenna radiation unit as described in any one of claims 1 to 6.

8. The dual-frequency common aperture antenna according to claim 7, characterized in that: The feed network layer (100b) comprises a plurality of mutually isolated multi-stage H-type stripline feed networks, the ends of the multi-stage H-type stripline feed networks having an electrical coupling structure (148) for electrically coupling with an H-type coupling slot array (130) arranged on the bottom surface of the antenna layer (100a) or the top surface of the feed network layer (100b) to conduct signals with the antenna layer (100a), and the input / output interlayer coupling slots of the multi-stage H-type stripline feed network connect the stripline and the waveguide switching layer (100c).

9. The dual-frequency common aperture antenna according to claim 8, characterized in that: The feeding network layer (100b) comprises four mutually isolated multi-stage H-type stripline feeding networks, namely a first H-type feeding network (140), a second H-type feeding network (142), a third H-type feeding network (144), and a fourth H-type feeding network (146); The signal transmission lengths of the first H-type feeding network (140) and the second H-type feeding network (142) are the same, and they are two orthogonal polarization feeding networks in the Ka frequency band; The third H-type feeding network (144) and the fourth H-type feeding network (146) have the same signal transmission length and are two orthogonal polarization feeding networks in the K frequency band.

10. The dual-frequency common aperture antenna according to claim 9, characterized in that: The feed network layer (100b) comprises two PCB layers, the first H-type feed network (140) and the third H-type feed network (144) are located on one of the PCB layers, and the second H-type feed network (142) and the fourth H-type feed network (146) are located on the other PCB layer; A bridge structure is used at the intersection of transmission branches of different multi-level H-type stripline feeding networks in the same PCB layer, and a transmission branch line (151) of one of the multi-level H-type stripline feeding networks at the intersection is disconnected, and vertical conductive vias (152) are respectively provided at two ends of the disconnection, and the two vertical conductive vias (152) are connected to the same transmission bridge line (153) located in another PCB layer.

11. The dual-frequency common aperture antenna according to claim 9, characterized in that: The stripline and waveguide switching layer (100c) comprises a plurality of switching units, wherein the switching units comprise signal transmission striplines (171) and coupling patches (172) located in different interlayers, wherein one end of the signal transmission stripline (171) is connected and conducted with the input end / output end of a multi-stage H-type stripline feeding network via an interlayer coupling gap, and the other end is connected and conducted with the coupling patch (172) via an H-type microstrip coupling gap (173).

12. The dual-frequency common aperture antenna according to claim 11, characterized in that: The multiple switching units include at least one pair of K-band switching units and at least one pair of Ka-band switching units; A circle of first grounding holes (174) arranged in a rectangular ring is provided on the circumference of the coupling patch (172), and the first grounding holes (174) are connected to the ground layer in the strip line and waveguide transition layer (100c); In the K-band switching unit, a rectangular area (175) surrounded by the first grounding hole (174) serves as a K-band input / output port (181); In the Ka-band switching unit, a rectangular area (175) surrounded by the first grounding hole (174) serves as a Ka-band input / output port (182).

13. The dual-frequency common aperture antenna according to claim 12, characterized in that: Second grounding holes (170) are respectively arranged in arrays on both sides of the signal transmission stripline (171) and on the periphery of the coupling patch (172); the second grounding holes (170) are connected to the ground layer in the stripline and waveguide switching layer (100c).

14. The dual-frequency common aperture antenna according to claim 11, characterized in that: The H-shaped microstrip coupling gap (173) comprises a straight section (173a) and an open rectangular ring (173b) symmetrically and vertically connected to both ends of the straight section (173a) in the length direction, wherein the opening of the open rectangular ring (173b) faces outward and is located on an extension line of the straight section (173a) in the length direction; In the layer height direction of the stripline and waveguide transition layer (100c), the projection of the signal transmission stripline (171) and the projection of the straight segment (173a) intersect vertically.

Images