A broadband dual-polarized hollow waveguide slot antenna

Abstract

The present invention discloses a broadband dual-polarized slot hollow waveguide antenna, which includes a radiation slot layer, an H-polarization full-common-feed feeding network, an orthogonal mode separation layer, and a V-polarization full-common-feed feeding network stacked from top to bottom. The V-polarization full-common-feed feeding network adopts a bottom-feed feeding method to excite the radiation slot layer to generate vertically polarized waves. The H-polarization full-common-feed feeding network adopts a side-feed feeding method to cause the radiation slot layer to generate horizontally polarized waves. The orthogonal mode separation layer is designed based on a double-ridge rectangular waveguide cavity. The radiation slot layer is used to generate vertically polarized waves under the excitation of the V-polarization full-common-feed feeding network and horizontally polarized waves under the excitation of the H-polarization full-common-feed feeding network, and synthesize the vertically polarized waves and the horizontally polarized waves into cross-polarized waves and radiate them into free space. The advantages are that while having a relatively wide impedance bandwidth, the grating lobe level will not deteriorate significantly, and it has a high antenna efficiency and a high cross-polarization (XPD).

Description

Technical Field

[0001] The present invention relates to a dual-polarized hollow waveguide slot antenna, and more particularly to a broadband dual-polarized hollow waveguide slot antenna. Background Art

[0002] With the emergence of various new wireless communication applications such as the Internet of Things, AR / VR, etc., the demand for wireless communication capacity has increased rapidly. In long-distance wireless communication scenarios, broadband, high-gain, and high-efficiency array antennas are the first choice for establishing stable communication. Among them, since broadband dual-polarized antennas can eliminate multipath fading and increase the channel capacity within a given spectrum, broadband dual-polarized antennas are a very good choice for forming array antennas. Given the advantages of broadband dual-polarized antennas, broadband dual-polarized antennas implemented using low-loss schemes have become very attractive. Parabolic reflectors and mirrors have the advantages of low cost and easy manufacturing, and are a common choice for designing broadband dual-polarized antennas at present. However, the broadband dual-polarized antennas designed based on parabolic reflectors and mirrors are very large in volume and very high in shape, and are increasingly unable to meet the current demand for miniaturization of products. The hollow waveguide slot antenna that has emerged in recent years has a compact structure and a small volume. When applied to an array antenna, it can make the array antenna compact in volume and achieve miniaturization, and has become an ideal candidate antenna for planar high-efficiency dual-polarized antennas.

[0003] The existing dual-polarized hollow waveguide slot antennas mainly fall into two categories: the first is based on a series (or partially series) feed network structure; the second is based on a full common-feed feed network structure. The dual-polarized hollow waveguide slot antenna based on the series (or partially series) feed network structure has two typical designs: (1) exciting a series of orthogonally arranged continuous transverse shorting arrays or crossed slot arrays, (2) exciting vertical and offset longitudinal slots in combination with a partially series feed network. For the convenience of the layout of the feed network, the two typical designs of the dual-polarized hollow waveguide slot antenna based on the series (or partially series) feed network structure both use a 1-4 back cavity to excite a 2×2 element subarray. The dual-polarized hollow waveguide slot antenna based on the full common-feed feed network structure realizes dual polarization using a cross-shaped slot, a square slot, and a magnetoelectric dipole, respectively.

[0004] However, the dual-polarized hollow waveguide slot antennas of the above two categories have the following problems: First, the fractional bandwidth (FBW) of the dual-polarized hollow waveguide slot antenna based on a series (or partially series) feed network structure is relatively narrow (FBW is usually within 10%), and for the dual-polarized hollow waveguide slot antenna based on a full common-feed feed network structure, due to the problem of the back cavity size, its FBW is still relatively narrow (less than 20%); Second, both of these two types of dual-polarized hollow waveguide slot antennas use a common back cavity to excite polarization, which will increase the possibility of cross-polarization deterioration. In addition, the method of enhancing the FBW by increasing the back cavity size will cause a significant deterioration of the grating lobe level (only about -13 dB), thus affecting the antenna efficiency. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a broadband hollow waveguide slot array antenna that has a relatively wide impedance bandwidth, does not have a significant deterioration in the grating lobe level, has a relatively high antenna efficiency, and has a relatively high cross-polarization (XPD).

[0006] The technical solution adopted by the present invention to solve the above technical problems is: A broadband dual-polarized slot hollow waveguide antenna, comprising a radiation slot layer, an H-polarized full common-feed feed network, an orthogonal mode separation layer, and a V-polarized full common-feed feed network stacked from top to bottom. The V-polarized full common-feed feed network adopts a bottom-feed feeding method. The V-polarized full common-feed feed network is used to excite the radiation slot layer to generate vertically polarized waves. The H-polarized full common-feed feed network is a compact feed network based on a hybrid structure of a double-ridge waveguide and a square coaxial line and realized by using a plurality of T-junctions. The H-polarized full common-feed feed network adopts a side-feed feeding method. The H-polarized full common-feed feed network is in direct contact with the radiation slot layer and is used to perform face-to-face excitation on the radiation slot layer so that the radiation slot layer generates horizontally polarized waves. The orthogonal mode separation layer is designed based on a double-ridge rectangular waveguide cavity. The orthogonal mode separation layer is used to increase the isolation between the vertically polarized waves excited by the V-polarized full common-feed feed network and the horizontally polarized waves excited by the H-polarized full common-feed feed network, and at the same time improve the impedance matching between the V-polarized full common-feed feed network and the radiation slot layer and the impedance matching between the H-polarized full common-feed feed network and the radiation slot layer. The radiation slot layer is designed based on a square slot element structure combined with side-feed and bottom-feed. The radiation slot layer is used to generate vertically polarized waves under the excitation of the V-polarized full common-feed feed network and horizontally polarized waves under the excitation of the H-polarized full common-feed feed network, and synthesize the vertically polarized waves and the horizontally polarized waves into cross-polarized waves and radiate them into free space, and at the same time realize a broadband impedance matching response to the cross-polarized waves.

[0007] The described radiation slot layer includes a first metal plate and a square radiation slot group unit disposed on the first metal plate. The first metal plate is a rectangular plate. The square radiation slot group unit is composed of 4 square radiation slot groups opened on the first metal plate. The 4 square radiation slot groups are arranged at equal intervals in a 2-row and 2-column manner. Among them, the 2 square radiation slot groups in the same row are symmetric about the symmetry line in the front-back direction of the first metal plate, and the 2 square radiation slot groups in the same column are symmetric about the symmetry line in the left-right direction of the first metal plate. Each of the square radiation slot groups includes 16 square radiation slots, and the 16 square radiation slots are evenly spaced in a 4-row and 4-column manner. Each of the square radiation slots is realized by opening a hollow square air slot on the first metal plate. The radiation slot layer has 64 square radiation slots;The described H-polarization full-common-feed feeding network includes a second metal plate and four 1-way 16-way equal-amplitude and anti-phase power dividers. The second metal plate is a rectangular plate and is located below the first metal plate. The four 1-way 16-way equal-amplitude and anti-phase power dividers have exactly the same structural dimensions and are respectively realized by slotting on the second metal plate. Each 1-way 16-way equal-amplitude and anti-phase power divider has one input port and sixteen output ports. The input ports of the four 1-way 16-way equal-amplitude and anti-phase power dividers are connected, and their connection end serves as one input port of the H-polarization full-common-feed feeding network. The sixteen output ports of the four 1-way 16-way equal-amplitude and anti-phase power dividers, a total of sixty-four output ports, serve as the sixty-four output ports of the H-polarization full-common-feed feeding network. The input port of the H-polarization full-common-feed feeding network uses a multi-stage rectangular waveguide stepped matching to transition to a standard waveguide input port (WR-51). Each 1-way 16-way equal-amplitude and anti-phase power divider is respectively composed of four 1-way 4-way equal-amplitude and anti-phase power dividers distributed at intervals in two rows and two columns. Each 1-way 4-way equal-amplitude and anti-phase power divider has one input port and four output ports. In each 1-way 16-way equal-amplitude and anti-phase power divider, the input ports of the four 1-way 4-way equal-amplitude and anti-phase power dividers are connected, and their connection end serves as the input port of the 1-way 16-way equal-amplitude and anti-phase power divider. The four output ports of the four 1-way 4-way equal-amplitude and anti-phase power dividers, a total of sixteen output ports, serve as the sixteen output ports of the 1-way 16-way equal-amplitude and anti-phase power divider. Each 1-way 4-way equal-amplitude and anti-phase power divider is respectively realized by connecting one H-plane double-ridge T-type 1-way 2-way power divider and two E-plane double-ridge T-type 1-way 2-way power dividers. The H-plane double-ridge T-type 1-way 2-way power divider is located in the middle of the two E-plane double-ridge T-type 1-way 2-way power dividers. The H-plane double-ridge T-type 1-way 2-way power divider has one input port and two output ports. The input port of the H-plane double-ridge T-type 1-way 2-way power divider uses a square coaxial structure. Each E-plane double-ridge T-type 1-way 2-way power divider has one input port and two output ports. Each output port of each E-plane double-ridge T-type 1-way 2-way power divider uses a square coaxial structure. The input port of the H-plane double-ridge T-type 1-way 2-way power divider is the input port of the 1-way 4-way equal-amplitude and anti-phase power divider. The two output ports of the H-plane double-ridge T-type 1-way 2-way power divider are respectively connected to the input ports of the two E-plane double-ridge T-type 1-way 2-way power dividers in one-to-one correspondence. The two output ports of the two E-plane double-ridge T-type 1-way 2-way power dividers, a total of four output ports, serve as the four output ports of the 1-way 4-way equal-amplitude and anti-phase power divider;The orthogonal mode splitting layer includes a third metal plate and 4 groups of double-ridge rectangular waveguide cavities arranged on the third metal plate. The third metal plate is a rectangular plate, and the 4 groups of double-ridge rectangular waveguide cavities are spaced apart in a 2-row and 2-column manner. The 2 groups of double-ridge rectangular waveguide cavities in the same row are symmetric about the symmetry line in the front-back direction of the third metal plate, and the 2 groups of double-ridge rectangular waveguide cavities in the same column are symmetric about the symmetry line in the left-right direction of the third metal plate. Each group of double-ridge rectangular waveguide cavities is composed of 16 double-ridge rectangular waveguide cavities. In each group of double-ridge rectangular waveguide cavities, the 16 double-ridge rectangular waveguide cavities are arranged at equal intervals in a 4-row and 4-column pattern. The 16 double-ridge rectangular waveguide cavities in each group of double-ridge rectangular waveguide cavities are equally divided into 4 double-ridge rectangular waveguide cavity sub-groups. Each double-ridge rectangular waveguide cavity sub-group includes 4 double-ridge rectangular waveguide cavities arranged at equal intervals in a 2-row and 2-column pattern. Each double-ridge rectangular waveguide cavity has a square coaxial input port on the side, a double-ridge waveguide input port at the bottom, and an output port. Each double-ridge rectangular waveguide cavity is realized by slotting on the third metal plate. The orthogonal mode splitting layer has 64 double-ridge rectangular waveguide cavities. The square coaxial input ports on the side of the 64 double-ridge rectangular waveguide cavities serve as the 64 side-fed square coaxial input ports of the orthogonal mode splitting layer. The double-ridge waveguide input ports at the bottom of the 64 double-ridge rectangular waveguide cavities serve as the 64 bottom-fed double-ridge waveguide input ports of the orthogonal mode splitting layer. The output ports of the 64 double-ridge rectangular waveguide cavities serve as the 64 output ports of the orthogonal mode splitting layer. The V-polarization full-common-feed feeding network includes a fourth metal plate and 4 1-to-16 equal-amplitude and in-phase power dividers. The fourth metal plate is a rectangular plate. The fourth metal plate is located below the third metal plate. The 4 1-to-16 equal-amplitude and in-phase power dividers have exactly the same structural dimensions and are respectively realized by slotting on the fourth metal plate. Each 1-to-16 equal-amplitude and in-phase power divider has 1 input port and 16 output ports. The input ports of the 4 1-to-16 equal-amplitude and in-phase power dividers are connected, and the connection port serves as the input port of the V-polarization full-common-feed feeding network. The input port of the V-polarization full-common-feed feeding network is transitioned to a standard waveguide input port (WR-51) by using a multi-stage rectangular waveguide step. The 16 output ports of the 4 1-to-16 equal-amplitude and in-phase power dividers, a total of 64 output ports, serve as the 64 output ports of the V-polarization full-common-feed feeding network.Each 1-way 16-way equal-amplitude in-phase power divider is respectively composed of 4 1-way 4-way equal-amplitude in-phase power dividers. Each 1-way 4-way equal-amplitude in-phase power divider has 1 input port and 4 output ports. The input ports of the 4 1-way 4-way equal-amplitude in-phase power dividers are connected, and the connection end serves as the input port of the 1-way 16-way equal-amplitude in-phase power divider. The 4 output ports of the 4 1-way 4-way equal-amplitude in-phase power dividers, a total of 16 output ports, serve as the 16 output ports of the 1-way 16-way equal-amplitude in-phase power divider. The output port of each 1-way 4-way equal-amplitude in-phase power divider is of a double-ridge waveguide structure; in each 1-way 16-way equal-amplitude in-phase power divider, each of the 1-way 4-way equal-amplitude in-phase power dividers is realized by cascading 3 H-plane single-ridge T-type 1-way 2-way power dividers in sequence. Each of the H-plane single-ridge T-type 1-way 2-way power dividers has one input port and two output ports. In each of the 1-way 4-way equal-amplitude in-phase power dividers, the input port of the middle H-plane single-ridge T-type 1-way 2-way power divider serves as the input port of the 1-way 4-way equal-amplitude in-phase power divider. The 2 output ports of the middle H-plane single-ridge T-type 1-way 2-way power divider are connected to the input ports of the H-plane single-ridge T-type 1-way 2-way power dividers on both sides in one-to-one correspondence. The 2 output ports of the 2 H-plane double-ridge T-type 1-way 2-way power dividers on both sides, a total of 4 output ports, serve as the 4 output ports of the 1-way 4-way equal-amplitude in-phase power divider; the 64 side-fed square coaxial input ports of the orthogonal mode splitting layer are connected to the 64 output ports of the H-polarization full common-feed feeding network in one-to-one correspondence. The 64 bottom-fed double-ridge waveguide input ports of the orthogonal mode splitting layer are connected to the 64 output ports of the V-polarization full common-feed feeding network in one-to-one correspondence. The 64 output ports of the orthogonal mode splitting layer are connected to the 64 square radiation slots of the radiation slot layer in one-to-one correspondence; when the broadband dual-polarized slot hollow waveguide antenna realizes the transmitting function, the standard waveguide input port (WR-51) connected to the input port of the H-polarization full common-feed feeding network is excited by the circuit to generate a TE mode with a frequency of 17 - 21.5 GHz. 10 mode, and the standard waveguide input port (WR-51) connected to the input port of the V-polarization full common-feed feeding network is excited by the circuit to generate a TE 10 mode, where the TE mode with a frequency of 17 - 21.5 GHz generated by the standard waveguide input port (WR-51) connected to the input port of the H-polarization full common-feed feeding network being excited by the circuit 10The TE10 mode is transmitted to the input port of the H-polarization full-common-feed feeding network, and then equally divided and transmitted to 16 1-way 4-way equal-amplitude and in-phase power dividers of the H-polarization full-common-feed feeding network. Each 1-way 4-way equal-amplitude and in-phase power divider of the H-polarization full-common-feed feeding network further equally divides the TE10 mode transmitted to it and transmits it to the double-ridge rectangular waveguide cavity of the orthogonal mode splitting layer connected to it. The standard waveguide input port (WR-51) connected to the input port of the V-polarization full-common-feed feeding network is excited by the circuit to generate the TE 10 mode, which is equally divided and transmitted to the input port of the V-polarization full-common-feed feeding network. The input port of the V-polarization full-common-feed feeding network converts the TE 10 mode into the TEM mode and equally divides it and transmits it to 64 1-way 4-way equal-amplitude and in-phase power dividers of the V-polarization full-common-feed feeding network. In the V-polarization full-common-feed feeding network, each 1-way 4-way equal-amplitude and in-phase power divider converts the TEM mode transmitted to it into the TE01 mode and then equally divides it and transmits it to the double-ridge rectangular waveguide cavity of the orthogonal mode splitting layer connected to it. The double-ridge rectangular waveguide cavity feeds the TE10 mode and the TE01 mode fed to it to the radiation slot layer respectively. The radiation slot layer generates horizontal polarization waves and vertical polarization waves and then forms cross-polarization waves and radiates them out.

[0008] Compared with the prior art, the advantages of the present invention are as follows. A broadband dual-polarized slot hollow waveguide antenna is realized by stacking a radiation slot layer, an H-polarized full-common-feed feeding network, a cross-mode separation layer, and a V-polarized full-common-feed feeding network from top to bottom. The V-polarized full-common-feed feeding network adopts a bottom-feed feeding method and is used to excite the radiation slot layer to generate vertically polarized waves. The H-polarized full-common-feed feeding network is a compact feeding network based on a hybrid structure of double-ridge waveguide and square coaxial line and realized by multiple T-junctions. The H-polarized full-common-feed feeding network adopts a side-feed feeding method and is in direct contact with the radiation slot layer to perform face-to-face excitation on the radiation slot layer, so that the radiation slot layer generates horizontally polarized waves. The cross-mode separation layer is designed based on a double-ridge rectangular waveguide cavity and is used to increase the isolation between the vertically polarized waves excited by the V-polarized full-common-feed feeding network and the horizontally polarized waves excited by the H-polarized full-common-feed feeding network, and at the same time improve the impedance matching between the V-polarized full-common-feed feeding network and the radiation slot layer and the impedance matching between the H-polarized full-common-feed feeding network and the radiation slot layer. The radiation slot layer is designed based on a square slot element structure combined with side-feed and bottom-feed methods and is used to generate vertically polarized waves under the excitation of the V-polarized full-common-feed feeding network and horizontally polarized waves under the excitation of the H-polarized full-common-feed feeding network, and synthesize the vertically polarized waves and horizontally polarized waves into cross-polarized waves and radiate them into free space, and at the same time realize the broadband impedance matching response to the cross-polarized waves. Therefore, the present invention adopts a feeding method combining side-feed and bottom-feed feeding methods to directly excite the radiation slot layer to achieve broadband dual-polarization characteristics, effectively reducing the number of radiation slots in the radiation slot layer, so that while having a relatively wide impedance bandwidth, the grating lobe level will not deteriorate significantly, and has a high antenna efficiency and a high cross-polarization (XPD). BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is an exploded view of the broadband dual-polarized slot hollow waveguide antenna of the present invention;

[0010] Figure 2 is a schematic structural diagram of the radiation slot layer of the broadband dual-polarized slot hollow waveguide antenna of the present invention;

[0011] Figure 3 is a schematic structural diagram of the H-polarized full-common-feed feeding network of the broadband dual-polarized slot hollow waveguide antenna of the present invention;

[0012] Figure 4 is a schematic structural diagram of the cross-mode separation layer of the broadband dual-polarized slot hollow waveguide antenna of the present invention;

[0013] Figure 5 is a schematic structural diagram of the V-polarized full-common-feed feeding network of the broadband dual-polarized slot hollow waveguide antenna of the present invention;

[0014] Figure 6 Side view of the broadband dual-polarized slot hollow waveguide antenna of the present invention;

[0015] Figure 7 Simulated and measured H-polarization reflection coefficient curve of the broadband dual-polarized slot hollow waveguide antenna of the present invention;

[0016] Figure 8 Simulated and measured V-polarization reflection coefficient curve of the broadband dual-polarized slot hollow waveguide antenna of the present invention. Detailed implementation manners

[0017] The present invention will be further described in detail below in conjunction with the embodiments with reference to the drawings.

[0018] Embodiment: As Figure 1 shown, a broadband dual-polarized slot hollow waveguide antenna includes a radiation slot layer 1, an H-polarization full-common-feed feeding network 2, a quadrature mode layer 3, and a V-polarization full-common-feed feeding network 4 stacked from top to bottom. The V-polarization full-common-feed feeding network 4 adopts a bottom-feed feeding method, and the V-polarization full-common-feed feeding network 4 is used to excite the radiation slot layer 1 to generate vertically polarized waves. The H-polarization full-common-feed feeding network 2 is a compact feeding network based on a hybrid structure of double-ridge waveguide and square coaxial line and realized by using a plurality of T-junctions. The H-polarization full-common-feed feeding network 2 adopts a side-feed feeding method, and the H-polarization full-common-feed feeding network 2 is in direct contact with the radiation slot layer 1 and is used to perform face-to-face excitation on the radiation slot layer 1 to make the radiation slot layer 1 generate horizontally polarized waves. The quadrature mode layer 3 is designed based on a double-ridge rectangular waveguide cavity. The quadrature mode layer 3 is used to increase the isolation between the vertically polarized waves excited by the V-polarization full-common-feed feeding network 4 and the horizontally polarized waves excited by the H-polarization full-common-feed feeding network 2, and at the same time improve the impedance matching between the V-polarization full-common-feed feeding network 4 and the radiation slot layer 1 and the impedance matching between the H-polarization full-common-feed feeding network 2 and the radiation slot layer 1. The radiation slot layer 1 is designed based on a square slot array element structure combined with side-feed and bottom-feed. The radiation slot layer 1 is used to generate vertically polarized waves under the excitation of the V-polarization full-common-feed feeding network 4 and horizontally polarized waves under the excitation of the H-polarization full-common-feed feeding network 2, and synthesize the vertically polarized waves and horizontally polarized waves into cross-polarized waves and radiate them into free space, and at the same time realize the broadband impedance matching response to the cross-polarized waves.

[0019] As Figures 2 to 5As shown, in this embodiment, the radiation slot layer 1 includes a first metal plate 5 and a square radiation slot group unit disposed on the first metal plate 5. The first metal plate 5 is a rectangular plate. The square radiation slot group unit is composed of 4 square radiation slot groups opened on the first metal plate 5. The 4 square radiation slot groups are arranged at equal intervals in a 2-row and 2-column manner. Among them, the 2 square radiation slot groups in the same row are symmetric about the symmetry line in the front-back direction of the first metal plate 5, and the 2 square radiation slot groups in the same column are symmetric about the symmetry line in the left-right direction of the first metal plate 5. Each square radiation slot group includes 16 square radiation slots 6, and the 16 square radiation slots 6 are evenly spaced in a 4-row and 4-column manner. Each square radiation slot 6 is respectively realized by opening a hollow square air groove on the first metal plate 5. The radiation slot layer 1 has 64 square radiation slots 6;The H-polarization full-common-feed feeding network 2 includes a second metal plate 7 and four 1-way 16-way equal-amplitude and anti-phase power dividers 8. The second metal plate 7 is a rectangular plate and is located below the first metal plate 5. The four 1-way 16-way equal-amplitude and anti-phase power dividers 8 have exactly the same structural dimensions and are respectively realized by slotting on the second metal plate 7. Each 1-way 16-way equal-amplitude and anti-phase power divider 8 has one input port and sixteen output ports. The input ports of the four 1-way 16-way equal-amplitude and anti-phase power dividers 8 are connected, and their connection end serves as one input port of the H-polarization full-common-feed feeding network 2. The sixteen output ports of the four 1-way 16-way equal-amplitude and anti-phase power dividers 8, a total of sixty-four output ports, serve as the sixty-four output ports of the H-polarization full-common-feed feeding network 2. The input port of the H-polarization full-common-feed feeding network 2 is matched and transitioned to a standard waveguide input port 11 (WR-51) by a multi-stage rectangular waveguide step 10. Each 1-way 16-way equal-amplitude and anti-phase power divider 8 is respectively composed of four 1-way 4-way equal-amplitude and anti-phase power dividers 9 arranged at intervals in two rows and two columns. Each 1-way 4-way equal-amplitude and anti-phase power divider 9 has one input port and four output ports. In each 1-way 16-way equal-amplitude and anti-phase power divider 8, the input ports of the four 1-way 4-way equal-amplitude and anti-phase power dividers 9 are connected, and their connection end serves as the input port of the 1-way 16-way equal-amplitude and anti-phase power divider 8. The four output ports of the four 1-way 4-way equal-amplitude and anti-phase power dividers 9, a total of sixteen output ports, serve as the sixteen output ports of the 1-way 16-way equal-amplitude and anti-phase power divider 8. Each 1-way 4-way equal-amplitude and anti-phase power divider 9 is respectively realized by connecting one H-plane double-ridge T-type 1-way 2-way power divider and two E-plane double-ridge T-type 1-way 2-way power dividers. The H-plane double-ridge T-type 1-way 2-way power divider is located in the middle of the two E-plane double-ridge T-type 1-way 2-way power dividers. The H-plane double-ridge T-type 1-way 2-way power divider has one input port and two output ports. The input port of the H-plane double-ridge T-type 1-way 2-way power divider adopts a square coaxial structure. Each E-plane double-ridge T-type 1-way 2-way power divider has one input port and two output ports. Each output port of each E-plane double-ridge T-type 1-way 2-way power divider adopts a square coaxial structure. The input port of the H-plane double-ridge T-type 1-way 2-way power divider is the input port of the 1-way 4-way equal-amplitude and anti-phase power divider 9. The two output ports of the H-plane double-ridge T-type 1-way 2-way power divider are respectively connected to the input ports of the two E-plane double-ridge T-type 1-way 2-way power dividers in one-to-one correspondence. The two output ports of the two E-plane double-ridge T-type 1-way 2-way power dividers, a total of four output ports, serve as the four output ports of the 1-way 4-way equal-amplitude and anti-phase power divider 9;The orthogonal mode-splitting layer 3 includes a third metal plate 12 and four dual-ridge rectangular waveguide cavity groups disposed on the third metal plate 12. The third metal plate 12 is a rectangular plate. The four dual-ridge rectangular waveguide cavity groups are spaced apart in a 2-row and 2-column manner. The two dual-ridge rectangular waveguide cavity groups in the same row are symmetric about the symmetry line in the front-rear direction with respect to the third metal plate 12, and the two dual-ridge rectangular waveguide cavity groups in the same column are symmetric about the symmetry line in the left-right direction with respect to the third metal plate 12. Each dual-ridge rectangular waveguide cavity group is composed of 16 dual-ridge rectangular waveguides 13. In each dual-ridge rectangular waveguide cavity group, the 16 dual-ridge rectangular waveguides 13 are arranged at equal intervals in a 4-row and 4-column manner. The 16 dual-ridge rectangular waveguides 13 in each dual-ridge rectangular waveguide cavity group are equally divided into four dual-ridge rectangular waveguide sub-groups. Each dual-ridge rectangular waveguide sub-group includes four dual-ridge rectangular waveguides 13 arranged at equal intervals in a 2-row and 2-column manner. Each dual-ridge rectangular waveguide 13 has a square coaxial input port 14 on the side, a dual-ridge waveguide input port 15 at the bottom, and an output port. Each dual-ridge rectangular waveguide is realized by slotting on the third metal plate 12. The orthogonal mode-splitting layer 3 has 64 dual-ridge rectangular waveguides. The square coaxial input ports 14 on the sides of the 64 dual-ridge rectangular waveguides serve as the 64 side-fed square coaxial input ports of the orthogonal mode-splitting layer 3. The dual-ridge waveguide input ports 15 at the bottoms of the 64 dual-ridge rectangular waveguides serve as the 64 bottom-fed dual-ridge waveguide input ports of the orthogonal mode-splitting layer 3. The output ports of the 64 dual-ridge rectangular waveguides serve as the 64 output ports of the orthogonal mode-splitting layer 3. The V-polarization full-common-feed feeding network 4 includes a fourth metal plate 16 and four 1-to-16 equal-amplitude and in-phase power dividers 17. The fourth metal plate 16 is a rectangular plate. The fourth metal plate 16 is located below the third metal plate 12. The four 1-to-16 equal-amplitude and in-phase power dividers 17 have exactly the same structural dimensions and are respectively realized by slotting on the fourth metal plate 16. Each 1-to-16 equal-amplitude and in-phase power divider 17 has one input port and 16 output ports. The input ports of the four 1-to-16 equal-amplitude and in-phase power dividers 17 are connected, and the connection port serves as the input port of the V-polarization full-common-feed feeding network 4. The input port of the V-polarization full-common-feed feeding network 4 is matched and transitioned to a standard waveguide input port 20 (WR-51) by a multi-stage rectangular waveguide step 19. The 16 output ports of the four 1-to-16 equal-amplitude and in-phase power dividers 17, a total of 64 output ports, serve as the 64 output ports of the V-polarization full-common-feed feeding network 4;Each 1-way 16-way equal-amplitude in-phase power divider 17 is respectively composed of 4 1-way 4-way equal-amplitude in-phase power dividers 18. Each 1-way 4-way equal-amplitude in-phase power divider 18 has 1 input port and 4 output ports. The input ports of the 4 1-way 4-way equal-amplitude in-phase power dividers 18 are connected, and the connection end serves as the input port of the 1-way 16-way equal-amplitude in-phase power divider 17. The 4 output ports of the 4 1-way 4-way equal-amplitude in-phase power dividers 18, a total of 16 output ports, serve as the 16 output ports of the 1-way 16-way equal-amplitude in-phase power divider 17. The output port of each 1-way 4-way equal-amplitude in-phase power divider 18 is of double-ridge waveguide structure; in each 1-way 16-way equal-amplitude in-phase power divider 17, each 1-way 4-way equal-amplitude in-phase power divider 18 is respectively realized by cascading 3 H-plane single-ridge T-type 1-way 2-way power dividers in sequence. Each H-plane single-ridge T-type 1-way 2-way power divider has one input port and two output ports. In each 1-way 4-way equal-amplitude in-phase power divider 18, the input port of the H-plane single-ridge T-type 1-way 2-way power divider in the middle serves as the input port of the 1-way 4-way equal-amplitude in-phase power divider 18. The 2 output ports of the H-plane single-ridge T-type 1-way 2-way power divider in the middle are connected to the input ports of the H-plane single-ridge T-type 1-way 2-way power dividers on both sides in one-to-one correspondence. The 2 output ports of the 2 H-plane double-ridge T-type 1-way 2-way power dividers on both sides, a total of 4 output ports, serve as the 4 output ports of the 1-way 4-way equal-amplitude in-phase power divider 18; the 64 side-fed square coaxial input ports of the orthogonal mode splitting layer 3 are connected to the 64 output ports of the H-polarization full common-feed feeding network 2 in one-to-one correspondence. The 64 bottom-fed double-ridge waveguide input ports of the orthogonal mode splitting layer 3 are connected to the 64 output ports of the V-polarization full common-feed feeding network 4 in one-to-one correspondence. The 64 output ports of the orthogonal mode splitting layer 3 are connected to the 64 square radiation slots of the radiation slot layer 1 in one-to-one correspondence; when the broadband dual-polarized slot hollow waveguide antenna realizes the transmitting function, the standard waveguide input port (WR-51) connected to the input port of the H-polarization full common-feed feeding network 2 is excited by the circuit to generate a TE mode with a frequency of 17 - 21.5 GHz; 10 mode, and the standard waveguide input port (WR-51) connected to the input port of the V-polarization full common-feed feeding network 4 is excited by the circuit to generate a TE 10 mode, where the TE mode with a frequency of 17 - 21.5 GHz generated by the standard waveguide input port 11 (WR-51) connected to the input port of the H-polarization full common-feed feeding network 2 being excited by the circuit 10The TE10 mode is transmitted to the input port of the H-polarization full-common-feed feeding network 2, and then equally divided and transmitted to the 16 1-way 4-way equal-amplitude and in-phase power dividers 18 of the H-polarization full-common-feed feeding network 2. Each 1-way 4-way equal-amplitude and in-phase power divider 18 of the H-polarization full-common-feed feeding network 2 further equally divides the TE10 mode transmitted thereto and transmits it to the double-ridge rectangular waveguide cavity of the orthogonal mode splitting layer 3 connected thereto. The standard waveguide input port 20 (WR-51) connected to the input port of the V-polarization full-common-feed feeding network 4 generates the TE 10 mode, which is equally divided and transmitted to the input port of the V-polarization full-common-feed feeding network 4. The input port of the V-polarization full-common-feed feeding network 4 converts the TE 10 mode into a TEM mode and equally divides it and transmits it to the 64 1-way 4-way equal-amplitude and in-phase power dividers 18 of the V-polarization full-common-feed feeding network 4. In the V-polarization full-common-feed feeding network 4, each 1-way 4-way equal-amplitude and in-phase power divider 18 converts the TEM mode transmitted thereto into a TE01 mode and then equally divides it and transmits it to the double-ridge rectangular waveguide cavity of the orthogonal mode splitting layer 3 connected thereto. The double-ridge rectangular waveguide cavity feeds the TE10 mode and the TE01 mode fed thereto to the radiation slot layer 1 respectively. The radiation slot layer 1 generates horizontal polarization waves and vertical polarization waves and then radiates cross-polarization waves.

[0020] The simulated and actually measured H-polarization reflection coefficient curves of the broadband dual-polarization slot hollow waveguide antenna of the present invention are as shown in Figure 7 The simulated and actually measured V-polarization reflection coefficient curves of the broadband dual-polarization slot hollow waveguide antenna of the present invention are as shown in Figure 8 Shown. Analysis Figure 7 and Figure 8 It can be seen that the actual test results are in good agreement with the simulation results. The slight differences are mainly due to manufacturing tolerances and assembly errors. The simulated relative bandwidth (|S11| < -10 dB) is 24.0% (16.9 - 21.5 GHz) and 27.4% (16.7 - 22.0 GHz) for H-polarization and V-polarization respectively. The measured H-polarization relative bandwidth is 23.4% (17.0 - 21.5 GHz), and the V-polarization FBW is 25.6% (17.0 - 22.0 GHz). Thus, the present invention has a relatively wide impedance bandwidth, the grating lobe level will not deteriorate significantly, and has a high antenna efficiency and a high cross-polarization (XPD).

Claims

1. A broadband dual-polarized slot hollow waveguide antenna, characterized in that it comprises a radiation slot layer, an H-polarization full-common-feed feeding network, a mode-separating layer, and a V-polarization full-common-feed feeding network stacked from top to bottom. The V-polarization full-common-feed feeding network adopts a bottom-feed feeding method and is used to excite the radiation slot layer to generate vertically polarized waves. The H-polarization full-common-feed feeding network is a compact feeding network based on a hybrid structure of double-ridge waveguide and square coaxial line and realized by using multiple T-junctions. The H-polarization full-common-feed feeding network adopts a side-feed feeding method and is in direct contact with the radiation slot layer for face-to-face excitation of the radiation slot layer to make the radiation slot layer generate horizontally polarized waves. The mode-separating layer is designed based on a double-ridge rectangular waveguide cavity and is used to increase the isolation between the vertically polarized waves excited by the V-polarization full-common-feed feeding network and the horizontally polarized waves excited by the H-polarization full-common-feed feeding network, and at the same time improve the impedance matching between the V-polarization full-common-feed feeding network and the radiation slot layer and the impedance matching between the H-polarization full-common-feed feeding network and the radiation slot layer. The radiation slot layer is designed based on a square slot array element structure combined with side-feed and bottom-feed methods and is used to generate vertically polarized waves under the excitation of the V-polarization full-common-feed feeding network and horizontally polarized waves under the excitation of the H-polarization full-common-feed feeding network, and synthesize the vertically polarized waves and horizontally polarized waves into cross-polarized waves and radiate them into free space, and at the same time realize the broadband impedance matching response to the cross-polarized waves; The described radiation slot layer includes a first metal plate and a square radiation slot group unit disposed on the first metal plate. The first metal plate is a rectangular plate. The square radiation slot group unit includes a plurality of square radiation slots, and each square radiation slot is realized by opening a hollow square air slot on the first metal plate. The H-polarization full common-feed feeding network includes a second metal plate and a plurality of 1-to-16 equal-amplitude and anti-phase power dividers. The second metal plate is a rectangular plate, and the second metal plate is located below the first metal plate. The 1-to-16 equal-amplitude and anti-phase power dividers are realized by slotting on the second metal plate, and each 1-to-16 equal-amplitude and anti-phase power divider has 1 input port and 16 output ports respectively. The orthogonal mode separation layer includes a third metal plate and a plurality of double-ridge rectangular waveguide cavities disposed on the third metal plate. The third metal plate is a rectangular plate, and each double-ridge rectangular waveguide cavity has a square coaxial input port on the side, a double-ridge waveguide input port at the bottom, and an output port. Each double-ridge rectangular waveguide cavity is realized by slotting on the third metal plate. The square coaxial input port on the side of each double-ridge rectangular waveguide cavity serves as its side-feed square coaxial input port, and the double-ridge waveguide input port at the bottom serves as its bottom-feed double-ridge waveguide input port. The V-polarization full common-feed feeding network includes a fourth metal plate and a plurality of 1-to-16 equal-amplitude and in-phase power dividers. The fourth metal plate is a rectangular plate, and the fourth metal plate is located below the third metal plate. The 1-to-16 equal-amplitude and in-phase power dividers are realized by slotting on the fourth metal plate, and each 1-to-16 equal-amplitude and in-phase power divider has 1 input port and 16 output ports respectively. The side-feed square coaxial input ports of the respective double-ridge rectangular waveguide cavities in the orthogonal mode separation layer are connected in one-to-one correspondence with the output ports of the respective 1-to-16 equal-amplitude and anti-phase power dividers in the H-polarization full common-feed feeding network. The bottom-feed double-ridge waveguide input ports of the respective double-ridge rectangular waveguide cavities in the orthogonal mode separation layer are connected in one-to-one correspondence with the output ports of the respective 1-to-16 equal-amplitude and in-phase power dividers in the V-polarization full common-feed feeding network. The output ports of the respective double-ridge rectangular waveguide cavities in the orthogonal mode separation layer are connected in one-to-one correspondence with the square radiation slots in the radiation slot layer.

2. A broadband dual-polarized slot hollow waveguide antenna according to claim 1, wherein the number of square radiation slots in the square radiation slot group unit is 64, forming 4 square radiation slot groups. The 4 square radiation slot groups are arranged at equal intervals in a 2-row and 2-column manner. Among them, the 2 square radiation slot groups in the same row are symmetric about the symmetry line in the front-back direction of the first metal plate left and right, and the 2 square radiation slot groups in the same column are symmetric about the symmetry line in the left-right direction of the first metal plate front and back. Each square radiation slot group includes 16 square radiation slots, and the 16 square radiation slots are evenly spaced in a 4-row and 4-column manner; The number of 1-way 16-way equal-amplitude and anti-phase power dividers in the described H-polarization full-common-feed feed network is 4. The structural dimensions of the 4 1-way 16-way equal-amplitude and anti-phase power dividers are exactly the same. The input ports of the 4 1-way 16-way equal-amplitude and anti-phase power dividers are connected, and their connection end serves as one input port of the H-polarization full-common-feed feed network. The 16 output ports of the 4 1-way 16-way equal-amplitude and anti-phase power dividers, a total of 64 output ports, serve as the 64 output ports of the H-polarization full-common-feed feed network. The input port of the H-polarization full-common-feed feed network is transitioned to a standard waveguide input port by a multi-stage rectangular waveguide step. Each 1-way 16-way equal-amplitude and anti-phase power divider is respectively composed of 4 1-way 4-way equal-amplitude and anti-phase power dividers distributed at intervals of 2 rows and 2 columns. Each 1-way 4-way equal-amplitude and anti-phase power divider has one input port and 4 output ports. In each 1-way 16-way equal-amplitude and anti-phase power divider, the input ports of the 4 1-way 4-way equal-amplitude and anti-phase power dividers are connected, and their connection end serves as the input port of the 1-way 16-way equal-amplitude and anti-phase power divider. The 4 output ports of the 4 1-way 4-way equal-amplitude and anti-phase power dividers, a total of 16 output ports, serve as the 16 output ports of the 1-way 16-way equal-amplitude and anti-phase power divider. Each 1-way 4-way equal-amplitude and anti-phase power divider is respectively realized by connecting 1 H-plane double-ridge T-type 1-way 2-way power divider and 2 E-plane double-ridge T-type 1-way 2-way power dividers. The H-plane double-ridge T-type 1-way 2-way power divider is located in the middle of the 2 E-plane double-ridge T-type 1-way 2-way power dividers. The H-plane double-ridge T-type 1-way 2-way power divider has one input port and two output ports. The input port of the H-plane double-ridge T-type 1-way 2-way power divider adopts a square coaxial structure. Each E-plane double-ridge T-type 1-way 2-way power divider has one input port and two output ports. Each output port of each E-plane double-ridge T-type 1-way 2-way power divider adopts a square coaxial structure. The input port of the H-plane double-ridge T-type 1-way 2-way power divider is the input port of the 1-way 4-way equal-amplitude and anti-phase power divider. The two output ports of the H-plane double-ridge T-type 1-way 2-way power divider are connected in one-to-one correspondence with the input ports of the 2 E-plane double-ridge T-type 1-way 2-way power dividers. The 2 output ports of the 2 E-plane double-ridge T-type 1-way 2-way power dividers, a total of 4 output ports, serve as the 4 output ports of the 1-way 4-way equal-amplitude and anti-phase power divider; The number of double-ridge rectangular waveguide cavities in the orthogonal mode-splitting layer is 64, which form 4 double-ridge rectangular waveguide cavity groups. The 4 double-ridge rectangular waveguide cavity groups are spaced apart in a 2-row and 2-column manner. The 2 double-ridge rectangular waveguide cavity groups in the same row are symmetric about the symmetry line in the front-back direction with respect to the third metal plate, and the 2 double-ridge rectangular waveguide cavity groups in the same column are symmetric about the symmetry line in the left-right direction with respect to the third metal plate. Each of the double-ridge rectangular waveguide cavity groups is composed of 16 double-ridge rectangular waveguide cavities. In each of the double-ridge rectangular waveguide cavity groups, the 16 double-ridge rectangular waveguide cavities are arranged at equal intervals in a 4-row and 4-column pattern. The 16 double-ridge rectangular waveguide cavities in each double-ridge rectangular waveguide cavity group are equally divided into 4 double-ridge rectangular waveguide cavity subgroups, and each double-ridge rectangular waveguide cavity subgroup includes 4 double-ridge rectangular waveguide cavities arranged at equal intervals in a 2-row and 2-column pattern. The number of 1-to-16 equal-amplitude and in-phase power dividers in the V-polarization full-common-feed feeding network is 4. The 4 1-to-16 equal-amplitude and in-phase power dividers have exactly the same structural dimensions. The input ports of the 4 1-to-16 equal-amplitude and in-phase power dividers are connected, and their connection port serves as the input port of the V-polarization full-common-feed feeding network. The input port of the V-polarization full-common-feed feeding network is transitioned to the standard waveguide input port by a multi-stage rectangular waveguide step matching. The 16 output ports of the 4 1-to-16 equal-amplitude and in-phase power dividers, a total of 64 output ports, serve as the 64 output ports of the V-polarization full-common-feed feeding network. Each 1-to-16 equal-amplitude and in-phase power divider is composed of 4 1-to-4 equal-amplitude and in-phase power dividers. Each 1-to-4 equal-amplitude and in-phase power divider has 1 input port and 4 output ports. The input ports of the 4 1-to-4 equal-amplitude and in-phase power dividers are connected, and their connection end serves as the input port of the 1-to-16 equal-amplitude and in-phase power divider. The 4 output ports of the 4 1-to-4 equal-amplitude and in-phase power dividers, a total of 16 output ports, serve as the 16 output ports of the 1-to-16 equal-amplitude and in-phase power divider. The output port of each 1-to-4 equal-amplitude and in-phase power divider is of a double-ridge waveguide structure. In each of the 1-to-16 equal-amplitude and in-phase power dividers, each 1-to-4 equal-amplitude and in-phase power divider is realized by cascading 3 H-plane single-ridge T-type 1-to-2 power dividers in sequence. Each of the H-plane single-ridge T-type 1-to-2 power dividers has one input port and two output ports. In each of the 1-to-4 equal-amplitude and in-phase power dividers, the input port of the H-plane single-ridge T-type 1-to-2 power divider in the middle serves as the input port of the 1-to-4 equal-amplitude and in-phase power divider. The 2 output ports of the H-plane single-ridge T-type 1-to-2 power divider in the middle are connected to the input ports of the H-plane single-ridge T-type 1-to-2 power dividers on both sides in a one-to-one correspondence. The 2 output ports of the 2 H-plane double-ridge T-type 1-to-2 power dividers on both sides, a total of 4 output ports, serve as the 4 output ports of the 1-to-4 equal-amplitude and in-phase power divider; When the broadband dual-polarized slot hollow waveguide antenna realizes the transmitting function, the standard waveguide input port connected to the input port of the H-polarized full-common-feed feeding network is excited by the circuit to generate a TE 10 mode at a frequency of 17 - 21.5 GHz, and the standard waveguide input port connected to the input port of the V-polarized full-common-feed feeding network is excited by the circuit to generate a TE 10 mode at a frequency of 17 - 21.5 GHz. Among them, the TE 10 mode at a frequency of 17 - 21.5 GHz generated by the circuit excitation of the standard waveguide input port connected to the input port of the H-polarized full-common-feed feeding network is transmitted to the input port of the H-polarized full-common-feed feeding network, and then equally divided and transmitted to 16 1-to-4 equal-amplitude and in-phase power dividers of the H-polarized full-common-feed feeding network. Each 1-to-4 equal-amplitude and in-phase power divider of the H-polarized full-common-feed feeding network further equally divides the TE10 mode transmitted to it and transmits it to the double-ridge rectangular waveguide cavity of the orthogonal mode splitting layer connected to it. The TE 10 mode at a frequency of 17 - 21.5 GHz generated by the circuit excitation of the standard waveguide input port connected to the input port of the V-polarized full-common-feed feeding network is equally divided and transmitted to the input port of the V-polarized full-common-feed feeding network. The input port of the V-polarized full-common-feed feeding network converts the TE 10 mode into a TEM mode and equally divides it and transmits it to 64 1-to-4 equal-amplitude and in-phase power dividers of the V-polarized full-common-feed feeding network. In the V-polarized full-common-feed feeding network, each 1-to-4 equal-amplitude and in-phase power divider converts the TEM mode transmitted to it into a TE01 mode and then equally divides it and transmits it to the double-ridge rectangular waveguide cavity of the orthogonal mode splitting layer connected to it. The double-ridge rectangular waveguide cavity feeds the TE10 mode and the TE01 mode fed to it to the radiation slot layer respectively. After the radiation slot layer generates horizontal polarized waves and vertical polarized waves, cross-polarized waves are radiated out.

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