Low-profile ultra-wideband antenna array

Abstract

A low-profile ultra-wideband antenna array disclosed by the present invention comprises a feed network and a radiation network, the feed network is realized based on a suspended microstrip line structure, the radiation network is realized by adopting a four-stage transition double-ridge waveguide horn structure, and a transmission network is arranged between the feed network and the radiation network. The transmission network is realized based on a horn coupling slot structure and a bent coupling slot structure, the feed network is used for generating coupling with the bent coupling slot structure in the transmission network and feeding an external radio frequency signal into the transmission network by adopting a suspended microstrip line feed mode, and the horn coupling slot structure in the transmission network is used for coupling with the radiation network. The radiation network is used for radiating the radio-frequency signals transmitted to the radiation network to a free space; the radio-frequency signals fed into the radiation network by the feed network are transmitted to the free space by the radiation network; the antenna has the advantages that the antenna can work in a 10-31 GHz satellite communication frequency band while having a low profile, the Ku wave band and the K wave band are completely covered, and compatibility of the low profile and the ultra wide band in a satellite communication system is achieved.

Description

Technical Field

[0001] The invention relates to an ultra-wideband antenna array, and in particular to a low-profile ultra-wideband antenna array. Background Art

[0002] As satellite communication systems develop towards multifunctionality and high integration, the space required for antennas as core components of satellite communication systems is gradually shrinking, while the requirements for working bandwidth are also increasing. Antennas with both low profile and wide bandwidth have a wide range of application needs. Reference [1] "Du Yongji, Wang Zehua, Zhang Chi, et al. K-band high-gain broadband heteropolarized transmittance / reflection array antenna [J]. Research and Progress in Solid-State Electronics, 2024, 44(02): 138-142." A broadband array antenna based on space feeding is proposed, which has the characteristics of high gain and low profile, and its working bandwidth is 18-27GHz. Reference [2] "Jiang Guangming, Yang Xiaoqing, Zhou Jian. Design of a Ku / K band broadband circularly polarized array antenna [J]. Modern Computer, 2022, 28(10): 67-71." proposes a low-profile broadband circularly polarized cross-dipole antenna array. The impedance bandwidth is widened by designing the contours of the four parasitic patches and the dipole arms as curves. At the same time, the profile height is reduced by replacing the traditional metal back cavity in the dielectric substrate with a metallized through hole. The operating bandwidth is 15.5-23.5GHz. Although the antenna arrays proposed in references [1] and [2] both achieve low-profile characteristics, the use of metallized through holes or specific parasitic structures also limits the propagation path of electromagnetic waves, making it impossible to achieve ultra-wideband impedance matching, resulting in the inability to further expand the bandwidth. It can only cover part of the Ku band and part of the K band. It is difficult to achieve compatibility of ultra-wideband and low profile in satellite communication systems at the same time, and the performance still needs to be improved. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a low-profile ultra-wideband antenna array that can operate in the 10-31 GHz satellite communication frequency band, completely covering the Ku band and the K band, and realizing low-profile and ultra-wideband compatibility in the satellite communication system.

[0004] The technical solution adopted by the present invention to solve the above technical problems is: a low-profile ultra-wideband antenna array, comprising a feeding network and a radiating network, wherein the feeding network is implemented based on a suspended microstrip line structure, and the radiating network is implemented using a double-ridged waveguide horn structure with a four-level transition, a transmission network is arranged between the feeding network and the radiating network, and the transmission network is implemented based on a horn coupling slot structure and a curved coupling slot structure, the feeding network is used to couple with the curved coupling slot structure in the transmission network, and an external radio frequency signal is fed into the transmission network using a suspended microstrip line feeding method, the horn coupling slot structure in the transmission network is used to couple with the radiating network, and the radio frequency signal fed into it by the feeding network is transmitted to the radiating network, and the radiating network is used to radiate the radio frequency signal transmitted thereto into free space.

[0005] Compared with the prior art, the present invention has the advantage of realizing a feeding network based on a suspended microstrip line structure, which effectively reduces the transmission loss of the feeding network and improves the stability of signal transmission, while making the overall design of the feeding network more compact and reducing the cross-section, and setting a transmission network between the feeding network and the radiating network, the transmission network is realized based on a horn coupling slot structure and a curved coupling slot structure, the transmission network is coupled with the feeding network through its inner curved coupling slot structure, and the horn coupling slot structure is coupled with the radiating network, the radio frequency signal is transmitted from the feeding network to the radiating network, the strength of the radio frequency signal is enhanced and the radiation loss is reduced. Loss, expand the working bandwidth, realize the radiation network based on the double-ridged waveguide horn structure with four-level transition, adjust the double-ridged waveguide horn structure characteristics through the four-level transition area to optimize step by step, so that the impedance of the double-ridged waveguide horn structure transitions step by step, thereby realizing smooth impedance matching within the ultra-wideband, and at the same time, the double-ridged waveguide horn structure improves the radiation efficiency of the radio frequency signal without increasing the vertical height of the antenna. Therefore, the present invention has both low profile and ultra-wideband characteristics, can cover the 10-31GHz satellite communication frequency band, and covers the complete Ku band and the complete K band, thus realizing low profile and ultra-wideband compatibility in satellite communication systems.

[0006] Furthermore, the radiation network includes a first metal plate and 32 radiation units arranged on the first metal plate, the length of the first metal plate is greater than its width, the length direction of the first metal plate is defined as the front-to-back direction, the width direction is defined as the left-to-right direction, and the height direction is defined as the up-down direction, the 32 radiation units are evenly spaced in 4 rows and 8 columns to form a radiation array, the row direction of the radiation array is along the front-to-back direction, and the column direction is along the left-to-right direction; each radiation unit includes a first hollow groove, a second hollow groove, two four-level transition double-ridge waveguide horns and a metal partition; the first hollow groove and the second hollow groove are both opened on the first metal plate, and the two are connected up and down to penetrate the first metal plate up and down, and the first hollow groove and the second hollow groove are both rectangular structures The structure has a length direction along the front-to-back direction, a width direction along the left-to-right direction, and a height direction along the up-down direction. The upper end surface of the first hollow groove is flush with the upper end surface of the first metal plate, and the lower end surface of the second hollow groove is flush with the lower end surface of the first metal plate. The upper end surface of the second hollow groove is in a fitted state with the lower end surface of the first hollow groove. The central axes of the first hollow groove and the second hollow groove in the up-down direction are located in the same straight line. The length of the second hollow groove is smaller than the length of the first hollow groove, and the width of the second hollow groove is smaller than the width of the first hollow groove. The plane that makes the first hollow groove symmetrical in the left-right direction is called the first symmetry plane of the radiation unit, and the plane that makes the first hollow groove symmetrical in the front-to-back direction is called the second symmetry plane of the radiation unit.The metal partition is located in the second hollow groove, the height direction of the metal partition is along the up-down direction, the length direction is along the front-to-back direction, the width is along the left-to-right direction, and its length is smaller than its width, the upper end face of the metal partition is flush with the upper end face of the second hollow groove, the lower end face of the metal partition is flush with the lower end face of the second hollow groove, the left end face of the metal partition is connected to the left end face of the second hollow groove and is in a fitted state, the right end face of the metal partition is connected to the right end face of the second hollow groove and is in a fitted state, the distance from the front end face of the metal partition to the front end face of the second hollow groove is equal to the distance from the rear end face of the metal partition to the rear end face of the second hollow groove, A third hollow groove is provided in the metal partition, and the third hollow groove is a rectangular parallelepiped structure. The length direction of the third hollow groove is along the front-to-back direction, the width direction is along the left-to-right direction, and the height direction is along the up-down direction. The upper end face of the third hollow groove is flush with the upper end face of the metal partition, the front end face of the third hollow groove is flush with the front end face of the metal partition, and the rear end face of the third hollow groove is flush with the rear end face of the metal partition. The height of the third hollow groove is less than the height of the metal partition, and the width of the third hollow groove is less than the width of the metal partition. The third hollow groove is left-right symmetrical about the first symmetry plane of the radiation unit, and the two four-stage transition double-ridge waveguide horns are respectively referred to as the first A four-level transition double-ridge waveguide horn and a second four-level transition double-ridge waveguide horn, the first four-level transition double-ridge waveguide horn includes a first waveguide step and a second waveguide step, the first waveguide step is arranged in the first hollow groove and the second hollow groove, and is located on the front side of the metal partition, the first waveguide step includes a connecting block, a first step, a second step, a third step and a fourth step, the connecting block, the first step, the second step, the third step and the fourth step are all rectangular structures, and the length direction is along the front-to-back direction, the width direction is along the left-right direction, and the height direction is along the up-down direction, the first step, the second step, the third step The lengths of the ladder and the fourth step are both smaller than their widths; the left end face of the connecting block is flush with the left end face of the first hollow groove, the right end face of the connecting block is flush with the left end face of the second hollow groove, the upper end face of the connecting block is flush with the upper end face of the first hollow groove, the lower end face of the connecting block is flush with the lower end face of the first hollow groove, there is a distance between the front end face of the connecting block and the front end face of the first hollow groove, there is a distance between the rear end face of the connecting block and the front end face of the metal partition, and the distance between the front end face of the connecting block and the front end face of the first hollow groove is equal to the distance between the rear end face of the connecting block and the front end face of the metal partition;The first step is located on the right side of the connecting block, the left end face of the first step is connected to the right end face of the connecting block and is in a fitted state, the upper end face of the first step is flush with the upper end face of the connecting block, the front end face of the first step is flush with the front end face of the connecting block, and the rear end face of the first step is flush with the rear end face of the connecting block. The second step is located below the first step, the upper end face of the second step is connected to the lower end face of the first step and is in a fitted state, the left end face of the second step is flush with the left end face of the first step, and the front end face of the second step is flush with the The front end face of the ladder is flush, the rear end face of the second step is flush with the rear end face of the first step, the width of the second step is greater than the width of the first step, the lower end face of the second step is located on the upper side of the lower end face of the first hollow groove, and there is a distance between the two, the third step is located below the second step, the upper end face of the third step is connected to the lower end face of the second step and is in a fitted state, the left end face of the third step is flush with the left end face of the second step, the front end face of the third step is flush with the front end face of the second step, and the rear end face of the third step is flush with the The rear end surface of the ladder is flush, the width of the third step is greater than the width of the second step, the lower end surface of the third step is located at the lower side of the lower end surface of the first hollow groove, and there is a distance between the two, the fourth step is located below the third step, the upper end surface of the fourth step is connected to the lower end surface of the third step and is in a fitted state, the left end surface of the fourth step is flush with the left end surface of the third step, the front end surface of the fourth step is flush with the front end surface of the third step, the rear end surface of the fourth step is flush with the rear end surface of the third step, and the width of the fourth step is greater than the width of the third step The width of the step, the lower end face of the fourth step is flush with the lower end face of the second hollow groove, the right end face of the fourth step is located on the left side of the first symmetry plane of the radiation unit, and there is a distance between the two; the second waveguide step is located on the right side of the first symmetry plane of the radiation unit and on the front side of the second symmetry plane of the radiation unit, the first waveguide step and the second waveguide step are symmetrical about the first symmetry plane of the radiation unit, the second four-level transition double-ridge waveguide horn is located on the rear side of the second symmetry plane of the radiation unit, and the first four-level transition double-ridge waveguide horn and the second four-level transition double-ridge waveguide horn are symmetrical about the second symmetry plane of the radiation unit. ;

[0007] Furthermore, the transmission network includes a metal patch and 32 transmission units arranged on the metal patch, the metal patch is located below the first metal plate, and its upper surface is in contact with the lower surface of the first metal plate, the metal patch is a rectangular structure, its length is along the front-to-back direction, its width is along the left-to-right direction, and its height is along the up-down direction, the front end face of the metal patch is flush with the front end face of the first metal plate, the rear end face of the metal patch is flush with the rear end face of the first metal plate, the left end face of the metal patch is flush with the left end face of the first metal plate, and the metal patch The right end surface of the metal patch is flush with the right end surface of the first metal plate; each transmission unit is realized by slotting the metal patch, and each transmission unit includes a fourth hollow groove and a fifth hollow groove, and the fourth hollow groove includes a first rectangular groove, an isosceles trapezoidal groove, a second rectangular groove, a curved groove and a third rectangular groove arranged in sequence from front to back, and the first rectangular groove, the isosceles trapezoidal groove, the second rectangular groove, the curved groove and the third rectangular groove all penetrate the metal patch from top to bottom, and the length directions of the first rectangular groove, the second rectangular groove and the third rectangular groove are all along the left-right direction, and the first rectangular groove The width directions of the isosceles trapezoidal groove, the second rectangular groove and the third rectangular groove are all along the front-to-back direction, the lower base of the isosceles trapezoidal groove is located in front of its upper base, and are all along the left-right direction, the first rectangular groove, the isosceles trapezoidal groove, the second rectangular groove and the third rectangular groove are symmetrical about the same plane, the length of the first rectangular groove is greater than the length of the lower base of the isosceles trapezoidal groove, the length of the upper base of the isosceles trapezoidal groove is equal to the length of the second rectangular groove, the curved groove is surrounded by the first arcuate surface, the first plane, the second arcuate surface and the second plane in sequence, and the first arcuate surface and the second arcuate surface are both oriented The front side is convex, and the two have different centers, the first plane and the second plane are located on the same vertical plane, the first plane is located on the left side of the second plane, the first rectangular groove, the isosceles trapezoidal groove, the second rectangular groove and the curved groove are connected in sequence from the front, the third rectangular groove is located on the rear side of the first plane of the curved groove, the front end surface of the third rectangular groove is connected to the first plane of the curved groove, and the two completely overlap; the fifth hollow groove is located on the rear side of the fourth hollow groove, there is a distance between the two, and the fourth hollow groove and the fifth hollow groove are symmetrical about a certain plane;The 32 transmission units correspond to the 32 radiation units one by one. In a corresponding transmission unit and a radiation unit, the fourth hollow groove and the fifth hollow groove of the transmission unit are front-to-back symmetrical about the second symmetry plane of the radiation unit, the first rectangular groove, the isosceles trapezoidal groove, the second rectangular groove and the third rectangular groove of the fourth hollow groove of the transmission unit are left-right symmetrical about the first symmetry plane of the radiation unit, the first plane and the second plane of the curved groove of the fourth hollow groove of the transmission unit are left-right symmetrical about the first symmetry plane of the radiation unit, and the rear end surface of the third rectangular groove of the fourth hollow groove of the transmission unit is symmetrical to the third rectangular groove of the fourth hollow groove of the transmission unit. The front end surface of the metal partition of the radiation unit is located in the same plane, the left end surface of the third rectangular groove of the fourth hollow groove of the transmission unit is located on the left side of the left end surface of the third hollow groove of the radiation unit, and the right end surface of the third rectangular groove of the fourth hollow groove of the transmission unit is located on the right side of the left end surface of the third hollow groove of the radiation unit; when a corresponding transmission unit and a radiation unit radiate to the same plane in the up-down direction, the first rectangular groove of the fourth hollow groove of the transmission unit is located between the first waveguide step and the second waveguide step of the first four-level transition double-ridge waveguide horn of the radiation unit, connecting the two. ;

[0008] Furthermore, the feeding network includes a second metal plate, an electromagnetic bandgap structure, a one-to-thirty-two power distribution network and a metal coaxial probe. The second metal plate is located below the metal patch, and its upper surface is at a distance from the lower surface of the metal patch. The second metal plate is a rectangular structure with a length along the front-to-back direction, a width along the left-to-right direction, and a height along the up-down direction. The front end face of the second metal plate is flush with the front end face of the metal patch, the rear end face of the second metal plate is flush with the rear end face of the metal patch, the left end face of the second metal plate is flush with the left end face of the metal patch, and the right end of the second metal plate is flush with the left end face of the metal patch. The surface is flush with the right end surface of the metal patch; a gap matching the outline of the one-to-thirty-two power distribution network is opened on the second metal plate, and the gap runs through the second metal plate from top to bottom. The one-to-thirty-two power distribution network is formed by arranging a microstrip line in the gap. The one-to-thirty-two power distribution network has an input end and 32 output ends. The 32 output ends of the one-to-thirty-two power distribution network correspond one-to-one to the 32 transmission units. The input end of the one-to-thirty-two power distribution network is connected to the metal coaxial probe, and the input end of the one-to-thirty-two power distribution network is connected to the metal coaxial probe through the metal coaxial probe. An external radio frequency signal, the one-to-thirty-two power distribution network is used to equally divide the external radio frequency signal connected to its input end into 32 radio frequency signals and couple and feed the external radio frequency signals into the curved groove of the fourth hollow groove and the symmetrical part of the curved groove of the fourth hollow groove in the fifth hollow groove of the 32 transmission units through its 32 output ends one by one; when the curved groove of the fourth hollow groove and the symmetrical part of the curved groove of the fourth hollow groove in the fifth hollow groove of a certain transmission unit are fed with radio frequency signals, the radio frequency signal at the curved groove of the fourth hollow groove of the transmission unit is transmitted to the first rectangular groove of the fourth hollow groove of the transmission unit, and then fed into the first four-stage transition double-ridge waveguide horn of the radiation unit corresponding to the transmission unit. Between a waveguide step and a second waveguide step, the radio frequency signal in the fifth hollow slot of the transmission unit which is symmetrical to the curved slot of the fourth hollow slot is transmitted to the fifth hollow slot of the transmission unit which is symmetrical to the first rectangular slot of the fourth hollow slot, and then fed into the second fourth-level transition double-ridge waveguide horn of the radiation unit corresponding to the transmission unit; the electromagnetic band gap structure is composed of a plurality of metal cylinders, the axes of the plurality of metal cylinders are all along the up-down direction, and the lower end faces thereof are all fixed and in a fitting state with the upper end face of the second metal plate, and the upper end faces thereof are all fixed and in a fitting state with the lower end face of the metal patch; the plurality of metal cylinders are distributed around the gap to prevent electromagnetic leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 An exploded view of a low-profile ultra-wideband antenna array of the present invention;

[0010] Figure 2 A structural diagram of a radiation network of a low-profile ultra-wideband antenna array of the present invention;

[0011] Figure 3 It is an overall stereogram of a single radiating unit of the low-profile ultra-wideband antenna array of the present invention;

[0012] Figure 4 A partial stereogram of a single radiating element of the low-profile ultra-wideband antenna array of the present invention

[0013] Figure 5 A perspective view of a first waveguide step of a low-profile ultra-wideband antenna array of the present invention;

[0014] Figure 6 A three-dimensional view of a metal partition of a low-profile ultra-wideband antenna array of the present invention;

[0015] Figure 7 A front view of a single radiating element of the low-profile ultra-wideband antenna array of the present invention;

[0016] Figure 8 The overall structure diagram of the transmission network of the low-profile ultra-wideband antenna array of the present invention;

[0017] Fig. 9 A perspective view of a single transmission unit of the low-profile ultra-wideband antenna array of the present invention;

[0018] Fig.10 A structural diagram of a feeding network of a low-profile ultra-wideband antenna array of the present invention;

[0019] Fig.11 A three-dimensional diagram of the electromagnetic band gap of the low-profile ultra-wideband antenna array of the present invention;

[0020] Fig.12 A three-dimensional diagram of a one-to-thirty-two power distribution network of a low-profile ultra-wideband antenna array of the present invention;

[0021] Fig.13 A perspective view of a metal coaxial probe of a low-profile ultra-wideband antenna array of the present invention;

[0022] Fig.14 A front view of a feed network of a low-profile ultra-wideband antenna array of the present invention;

[0023] Fig.15 This is a return loss characteristic diagram of the low-profile ultra-wideband antenna array of the present invention. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below with reference to the accompanying drawings.

[0025] Embodiment 1: Figure 1 As shown, a low-profile ultra-wideband antenna array includes a feeding network 1 and a radiating network 2, wherein the feeding network 1 is implemented based on a suspended microstrip line structure, and the radiating network 2 is implemented using a double-ridged waveguide horn structure with a four-level transition. A transmission network 3 is provided between the feeding network 1 and the radiating network 2, and the transmission network 3 is implemented based on a horn coupling slot structure and a curved coupling slot structure. The feeding network 1 is used to couple with the curved coupling slot structure in the transmission network 3, and feed an external RF signal into the transmission network 3 using a suspended microstrip line feeding method. The horn coupling slot structure in the transmission network 3 is used to couple with the radiating network 2, and transmit the RF signal fed thereto by the feeding network 1 to the radiating network 2, and the radiating network 2 is used to radiate the RF signal transmitted thereto into free space.

[0026] In this embodiment, the feeding network 1 is realized based on a suspended microstrip line structure. The suspended microstrip line structure effectively reduces the transmission loss of the feeding network 1 and improves the stability of signal transmission, while making the overall design of the feeding network 1 more compact and reducing the cross-section. A transmission network 3 is arranged between the feeding network 1 and the radiation network 2. The transmission network 3 is realized based on a horn coupling slot structure and a curved coupling slot structure. The transmission network 3 is coupled with the feeding network 1 through its inner curved coupling slot structure, and the horn coupling slot structure is coupled with the radiation network 2, so that the RF signal is transmitted from the feeding network 1 to the radiation network 2, the strength of the RF signal is enhanced, the loss is reduced, and the working bandwidth is expanded. The radiation network 2 is realized based on a double-ridged waveguide horn structure with four-level transition. The double-ridged waveguide horn structure characteristics are adjusted through the four-level transition region for step-by-step optimization, so that the impedance of the double-ridged waveguide horn structure is gradually transitioned, thereby realizing smooth impedance matching within an ultra-wideband. At the same time, the double-ridged waveguide horn structure improves the radiation efficiency of the RF signal without increasing the vertical height of the antenna.

[0027] Embodiment 2: This embodiment is basically the same as Embodiment 1, except that: in this embodiment, Figures 2 to 7As shown, the radiation network 2 includes a first metal plate 4 and 32 radiation units 5 arranged on the first metal plate 4. The length of the first metal plate 4 is greater than its width. The length direction of the first metal plate 4 is defined as the front-to-back direction, the width direction is defined as the left-to-right direction, and the height direction is defined as the up-down direction. The 32 radiation units 5 are evenly spaced in 4 rows and 8 columns to form a radiation array. The row direction of the radiation array is along the front-to-back direction, and the column direction is along the left-to-right direction. Each radiation unit 5 includes a first hollow slot 6, a second hollow slot 7, two four-level transition double-ridge waveguide horns and a metal partition 8. The first hollow slot 6 and the second hollow slot 7 are both opened on the first metal plate 4, and the two are connected up and down to penetrate the first metal plate 4 up and down. The first hollow slot 6 and the second hollow slot 7 are A rectangular parallelepiped structure, and its length direction is along the front-to-back direction, the width direction is along the left-to-right direction, and the height direction is along the up-down direction. The upper end surface of the first hollow groove 6 is flush with the upper end surface of the first metal plate 4, and the lower end surface of the second hollow groove 7 is flush with the lower end surface of the first metal plate 4. The upper end surface of the second hollow groove 7 is in a fitted state with the lower end surface of the first hollow groove 6. The central axis of the first hollow groove 6 and the second hollow groove 7 along the up-down direction are located in the same straight line. The length of the second hollow groove 7 is less than the length of the first hollow groove 6, and the width of the second hollow groove 7 is less than the width of the first hollow groove 6. The plane that makes the first hollow groove 6 symmetrical in the left-right direction is called the first symmetry plane of the radiation unit 5, and the plane that makes the first hollow groove 6 symmetrical in the front-to-back direction is called the second symmetry plane of the radiation unit 5;The metal partition plate 8 is located in the second hollow groove 7, the height direction of the metal partition plate 8 is along the up-down direction, the length direction is along the front-back direction, the width is along the left-right direction, and its length is smaller than its width, the upper end face of the metal partition plate 8 is flush with the upper end face of the second hollow groove 7, the lower end face of the metal partition plate 8 is flush with the lower end face of the second hollow groove 7, the left end face of the metal partition plate 8 is connected to the left end face of the second hollow groove 7 and is in a fitted state, the right end face of the metal partition plate 8 is connected to the right end face of the second hollow groove 7 and is in a fitted state, the distance from the front end face of the metal partition plate 8 to the front end face of the second hollow groove 7 is equal to the distance from the rear end face of the metal partition plate 8 to the rear end face of the second hollow groove 7, and a third hollow groove is provided in the metal partition plate 8. The third hollow slot 9 is a rectangular parallelepiped structure. The length direction of the third hollow slot 9 is along the front-to-back direction, the width direction is along the left-to-right direction, and the height direction is along the up-down direction. The upper end face of the third hollow slot 9 is flush with the upper end face of the metal partition 8, the front end face of the third hollow slot 9 is flush with the front end face of the metal partition 8, and the rear end face of the third hollow slot 9 is flush with the rear end face of the metal partition 8. The height of the third hollow slot 9 is less than the height of the metal partition 8, and the width of the third hollow slot 9 is less than the width of the metal partition 8. The third hollow slot 9 is symmetrical about the first symmetry plane of the radiation unit 5. The two four-level transition double-ridged waveguide horns are respectively referred to as the first four-level transition double-ridged waveguide horn 10 and the second four-level transition double-ridged waveguide horn 10. The first four-stage transition double-ridge waveguide horn 11 includes a first waveguide step 12 and a second waveguide step 13. The first waveguide step 12 is arranged in the first hollow groove 6 and the second hollow groove 7, and is located on the front side of the metal partition 8. The first waveguide step 12 includes a connecting block 14, a first step 15, a second step 16, a third step 17 and a fourth step 18. The connecting block 14, the first step 15, the second step 16, the third step 17 and the fourth step 18 are all rectangular structures, and the length direction is along the front-to-back direction, the width direction is along the left-right direction, and the height direction is along the up-down direction. The first step 15, the second step 16, The lengths of the third step 17 and the fourth step 18 are both smaller than their widths; the left end face of the connecting block 14 is flush with the left end face of the first hollow groove 6, the right end face of the connecting block 14 is flush with the left end face of the second hollow groove 7, the upper end face of the connecting block 14 is flush with the upper end face of the first hollow groove 6, the lower end face of the connecting block 14 is flush with the lower end face of the first hollow groove 6, there is a distance between the front end face of the connecting block 14 and the front end face of the first hollow groove 6, there is a distance between the rear end face of the connecting block 14 and the front end face of the metal partition 8, and the distance between the front end face of the connecting block 14 and the front end face of the first hollow groove 6 is equal to the distance between the rear end face of the connecting block 14 and the front end face of the metal partition 8;The first step 15 is located on the right side of the connecting block 14, the left end face of the first step 15 is connected to the right end face of the connecting block 14 and is in a fitted state, the upper end face of the first step 15 is flush with the upper end face of the connecting block 14, the front end face of the first step 15 is flush with the front end face of the connecting block 14, and the rear end face of the first step 15 is flush with the rear end face of the connecting block 14, and the second step 16 is located below the first step 15, the upper end face of the second step 16 is connected to the lower end face of the first step 15 and is in a fitted state, the left end face of the second step 16 is flush with the left end face of the first step 15, and the front end face of the second step 16 is flush with the front end face of the first step 15. The rear end face of the second step 16 is flush with the rear end face of the first step 15, the width of the second step 16 is greater than the width of the first step 15, the lower end face of the second step 16 is located on the upper side of the lower end face of the first hollow groove 6, and there is a distance between the two, the third step 17 is located below the second step 16, the upper end face of the third step 17 is connected to the lower end face of the second step 16 and is in a fitted state, the left end face of the third step 17 is flush with the left end face of the second step 16, the front end face of the third step 17 is flush with the front end face of the second step 16, and the rear end face of the third step 17 is flush with the rear end face of the second step 16 The width of the third step 17 is greater than the width of the second step 16, the lower end surface of the third step 17 is located at the lower side of the lower end surface of the first hollow groove 6, and there is a distance between the two, the fourth step 18 is located below the third step 17, the upper end surface of the fourth step 18 is connected to the lower end surface of the third step 17 and is in a fitted state, the left end surface of the fourth step 18 is flush with the left end surface of the third step 17, the front end surface of the fourth step 18 is flush with the front end surface of the third step 17, the rear end surface of the fourth step 18 is flush with the rear end surface of the third step 17, the width of the fourth step 18 is greater than the width of the third step 17, and the fourth step The lower end surface of the ladder 18 is flush with the lower end surface of the second hollow groove 7, the right end surface of the fourth step 18 is located on the left side of the first symmetry plane of the radiation unit 5, and there is a distance between the two; the second waveguide step 13 is located on the right side of the first symmetry plane of the radiation unit 5 and on the front side of the second symmetry plane of the radiation unit 5, the first waveguide step 12 and the second waveguide step 13 are symmetrical about the first symmetry plane of the radiation unit 5, the second fourth-level transition double-ridge waveguide horn 11 is located on the rear side of the second symmetry plane of the radiation unit 5, and the first fourth-level transition double-ridge waveguide horn 10 and the second fourth-level transition double-ridge waveguide horn 11 are symmetrical about the second symmetry plane of the radiation unit 5. ;

[0028] In this embodiment, the radiation network 2 is realized based on the double-ridged waveguide horn structure of the four-level transition, the double-ridged waveguide horn structure of the four-level transition is realized based on the first four-level transition double-ridged waveguide horn 10 and the second four-level transition double-ridged waveguide horn 11, the first four-level transition double-ridged waveguide horn 10 is realized based on the first waveguide step 12 and the second waveguide step 13, the first waveguide step 12 is realized based on the connecting block 14, the first step 15, the second step 16, the third step 17 and the fourth step 18, the first waveguide step 12 is realized, the first waveguide step 12 is connected and fixed to the first metal plate 4 through the connecting block 14, and the double-ridged waveguide horn structure is realized step by step through the four steps of the fourth step 18, the third step 17, the second step 16 and the first step 15. The structural characteristics of the ridge waveguide horn allow the impedance of the double-ridged waveguide horn structure to transition step by step, thereby achieving smooth impedance matching within an ultra-wideband, so that when the transmission network 3 feeds the RF signal into the first four-level transition double-ridged waveguide horn 10 (between the first waveguide step 12 and the second waveguide step 13), it can be smoothly radiated from the radiation network 2 to the free space. Similarly, when the transmission network 3 feeds the RF signal into the second four-level transition double-ridged waveguide horn 11, it can also be smoothly radiated from the radiation network 2 to the free space. The first four-level transition double-ridged waveguide horn 10 and the second four-level transition double-ridged waveguide horn 11 both adopt a double-ridged waveguide horn structure, and the RF signal is diffused and transmitted outward, so that the radiation efficiency of the RF signal is improved without increasing the vertical height of the antenna.

[0029] Embodiment 3: This embodiment is basically the same as Embodiment 2, except that: in this embodiment, Figure 8 and Fig. 9As shown, the transmission network 3 includes a metal patch 19 and 32 transmission units 20 arranged on the metal patch 19. The metal patch 19 is located below the first metal plate 4, and its upper surface is in contact with the lower surface of the first metal plate 4. The metal patch 19 is a rectangular parallelepiped structure with a length along the front-to-back direction, a width along the left-to-right direction, and a height along the up-down direction. The front end face of the metal patch 19 is flush with the front end face of the first metal plate 4, the rear end face of the metal patch 19 is flush with the rear end face of the first metal plate 4, the left end face of the metal patch 19 is flush with the left end face of the first metal plate 4, and the right end face of the metal patch 19 is flush with the right end face of the first metal plate 4; each The transmission units 20 are all realized by slotting the metal patch 19, and each transmission unit 20 includes a fourth hollow slot 21 and a fifth hollow slot 22. The fourth hollow slot 21 includes a first rectangular slot 23, an isosceles trapezoidal slot 24, a second rectangular slot 25, a curved slot 26 and a third rectangular slot 27 arranged in sequence from front to back. The first rectangular slot 23, the isosceles trapezoidal slot 24, the second rectangular slot 25, the curved slot 26 and the third rectangular slot 27 all penetrate the metal patch 19 from top to bottom. The length directions of the first rectangular slot 23, the second rectangular slot 25 and the third rectangular slot 27 are all along the left-right direction, and the width directions of the first rectangular slot 23, the second rectangular slot 25 and the third rectangular slot 27 are all along the left-right direction. The first rectangular groove 23, the isosceles trapezoidal groove 24, the second rectangular groove 25 and the third rectangular groove 27 are all along the front-to-back direction, the lower base of the isosceles trapezoidal groove 24 is located in front of its upper base, and are all along the left-right direction. The first rectangular groove 23, the isosceles trapezoidal groove 24, the second rectangular groove 25 and the third rectangular groove 27 are symmetrical about the same plane. The length of the first rectangular groove 23 is greater than the length of the lower base of the isosceles trapezoidal groove 24, and the length of the upper base of the isosceles trapezoidal groove 24 is equal to the length of the second rectangular groove 25. The curved groove 26 is surrounded by the first arc surface 261, the first plane 262, the second arc surface 263 and the second plane 264 connected in sequence. The first arc surface 261 and the second arc surface 263 are both convex to the front side, and the two have different centers. The first arc surface 261 is located at On the front side of the second arc-shaped surface 263, the first plane 262 and the second plane 264 are located on the same vertical plane, the first plane 262 is located on the left side of the second plane 264, the first rectangular groove 23, the isosceles trapezoidal groove 24, the second rectangular groove 25 and the curved groove 26 are connected in sequence from the front, the third rectangular groove 27 is located on the rear side of the first plane 262 of the curved groove 26, the front end surface of the third rectangular groove 27 is connected to the first plane 262 of the curved groove 26, and the two completely overlap; the fifth hollow groove 22 is located on the rear side of the fourth hollow groove 21, there is a distance between the two, and the fourth hollow groove 21 and the fifth hollow groove 22 are symmetrical about a certain plane;The 32 transmission units 20 correspond to the 32 radiation units 5 one by one. In a corresponding transmission unit 20 and a radiation unit 5, the fourth hollow groove 21 and the fifth hollow groove 22 of the transmission unit 20 are front-to-back symmetrical about the second symmetry plane of the radiation unit 5, the first rectangular groove 23, the isosceles trapezoidal groove 24, the second rectangular groove 25 and the third rectangular groove 27 of the fourth hollow groove 21 of the transmission unit 20 are left-right symmetrical about the first symmetry plane of the radiation unit 5, the first plane 262 and the second plane 264 of the curved groove 26 of the fourth hollow groove 21 of the transmission unit 20 are left-right symmetrical about the first symmetry plane of the radiation unit 5, and the third rectangular groove 27 of the fourth hollow groove 21 of the transmission unit 20 is left-right symmetrical. The rear end face of the transmission unit 20 is located in the same plane as the front end face of the metal partition 8 of the radiation unit 5, the left end face of the third rectangular slot 27 of the fourth hollow slot 21 of the transmission unit 20 is located on the left side of the left end face of the third hollow slot 9 of the radiation unit 5, and the right end face of the third rectangular slot 27 of the fourth hollow slot 21 of the transmission unit 20 is located on the right side of the left end face of the third hollow slot 9 of the radiation unit 5; when a corresponding transmission unit 20 and a radiation unit 5 radiate to the same plane in the up-down direction, the first rectangular slot 23 of the fourth hollow slot 21 of the transmission unit 20 is located between the first waveguide step 12 and the second waveguide step 13 of the first four-stage transition double-ridge waveguide horn 10 of the radiation unit 5, connecting the two. ;

[0030] In this embodiment, the transmission network 3 is realized based on the metal patch 19 and 32 transmission units 20 arranged on the metal patch 19, each transmission unit 20 includes a fourth hollow groove 21 and a fifth hollow groove 22, and the fourth hollow groove 21 is realized based on the first rectangular groove 23, the isosceles trapezoidal groove 24, the second rectangular groove 25, the curved groove 26 and the third rectangular groove 27 which are arranged and connected in sequence from front to back, the curved groove 26 and the third rectangular groove 27 form a curved coupling slot structure, the first rectangular groove 23, the isosceles trapezoidal groove 24 and the second rectangular groove 25 form a speaker coupling slot structure, and since the fifth hollow groove 22 is symmetrical with the fourth hollow groove 21, there is also a curved coupling slot structure and a speaker coupling slot structure in the fifth hollow groove 22, thereby, there are two speaker coupling slot structures and two curved coupling slot structures in each transmission unit 20 of the transmission network 3, and the two curved coupling slot structures are as a whole, and The feeding network 1 generates coupling, and the feeding network 1 feeds the RF signal into the two curved coupling slot structures of each transmission unit 20. Each curved coupling slot structure of each transmission unit 20 transmits the RF signal to the horn coupling slot structure connected thereto respectively. The two horn coupling slot structures of each transmission unit 20 correspond one-to-one with the first four-level transition double-ridged waveguide horn 10 and the second four-level transition double-ridged waveguide horn 11 of a radiation unit to generate coupling, and the RF signal is fed into the first four-level transition double-ridged waveguide horn 10 and the second four-level transition double-ridged waveguide horn 11 of the radiation unit. The first four-level transition double-ridged waveguide horn 10 and the second four-level transition double-ridged waveguide horn 11 of each radiation unit radiate the RF signal fed thereto into the free space. In the entire RF signal coupling and transmission process, horn structures are used in multiple places, so as to enhance the strength of the RF signal, reduce its loss, and expand the overall working bandwidth.

[0031] Embodiment 4: This embodiment is basically the same as Embodiment 3, except that: in this embodiment, Fig.10 and Fig.14As shown, the feeding network 1 includes a second metal plate 28, an electromagnetic bandgap structure 29, a one-to-thirty-two power distribution network 30 and a metal coaxial probe 31. The second metal plate 28 is located below the metal patch 19, and its upper surface is at a distance from the lower surface of the metal patch 19. The second metal plate 28 is a rectangular parallelepiped structure with a length along the front-to-back direction, a width along the left-to-right direction, and a height along the up-down direction. The front end face of the second metal plate 28 is flush with the front end face of the metal patch 19, the rear end face of the second metal plate 28 is flush with the rear end face of the metal patch 19, the left end face of the second metal plate 28 is flush with the left end face of the metal patch 19, and the right end face of the second metal plate 28 is flush with the right end face of the metal patch 19; the second metal The metal plate 28 is provided with a slot matching the outline of the one-to-thirty-two power distribution network 30, and the slot runs through the second metal plate 28 from top to bottom. The one-to-thirty-two power distribution network 30 is formed by setting a microstrip line in the slot. The one-to-thirty-two power distribution network 30 has an input end and 32 output ends. The 32 output ends of the one-to-thirty-two power distribution network 30 correspond to the 32 transmission units 20 one by one. The input end of the one-to-thirty-two power distribution network 30 is connected to the metal coaxial probe 31. The input end of the one-to-thirty-two power distribution network 30 is connected to the external radio frequency signal through the metal coaxial probe 31. The one-to-thirty-two power distribution network 30 is used to divide the external radio frequency signal connected to its input end into 32 equal paths. The radio frequency signal is coupled and fed into the curved groove 26 of the fourth hollow groove 21 and the fifth hollow groove 22 of the 32 transmission units 20 at the positions symmetrical to the curved groove 26 of the fourth hollow groove 21 through the 32 output ends thereof; when the radio frequency signal is fed into the curved groove 26 of the fourth hollow groove 21 and the fifth hollow groove 22 of a certain transmission unit 20 at the positions symmetrical to the curved groove 26 of the fourth hollow groove 21, the radio frequency signal at the curved groove 26 of the fourth hollow groove 21 of the transmission unit 20 is transmitted to the first rectangular groove 23 of the fourth hollow groove 21 of the transmission unit 20, and then fed into the first waveguide step 12 and the second waveguide step 10 of the first four-level transition double-ridge waveguide horn 10 of the radiation unit 5 corresponding to the transmission unit 20. 13, the RF signal at the position symmetrical to the curved groove 26 of the fourth hollow groove 21 in the fifth hollow groove 22 of the transmission unit 20 is transmitted to the position symmetrical to the first rectangular groove 23 of the fourth hollow groove 21 in the fifth hollow groove 22 of the transmission unit 20, and then fed into the second fourth-level transition double-ridge waveguide horn 11 of the radiation unit 5 corresponding to the transmission unit 20; the electromagnetic band gap structure 29 is composed of a plurality of metal cylinders 32, the axes of the plurality of metal cylinders 32 are all along the up and down directions, and the lower end faces thereof are fixed and fitted with the upper end face of the second metal plate 28, and the upper end faces thereof are fixed and fitted with the lower end face of the metal patch 19; the plurality of metal cylinders 32 are distributed around the gap to prevent electromagnetic leakage.

[0032] In order to verify the performance of the low-profile ultra-wideband antenna array of the present invention, the low-profile ultra-wideband antenna array of the present invention was simulated, and the low-profile ultra-wideband antenna array of the present invention was actually manufactured based on the simulation data and then tested. The simulated and measured return loss characteristic diagrams of the low-profile ultra-wideband antenna array of the present invention are shown in Figure 15.

[0033] Fig.15 In the table, Simulated represents the simulation result, and Mearsured represents the actual test result. Fig.15 From the simulation results, it can be seen that within the 10-31 GHz frequency band, the reflection coefficient (|S11|) of the low-profile ultra-wideband antenna array of the present invention is lower than -10dB in the entire frequency band, and even lower than -20dB in some frequency bands. This indicates that the low-profile ultra-wideband antenna array of the present invention has low reflection loss and high transmission efficiency during signal transmission, while maintaining a stable gain characteristic and a small fluctuation amplitude in the entire frequency band. This indicates that the low-profile ultra-wideband antenna array of the present invention can make the signal more stable during transmission, effectively improving the reliability of the communication link. Fig.15 The simulation results shown are basically consistent with the actual test results, further verifying the accuracy and reliability of the low-profile ultra-wideband antenna array of the present invention. For satellite communications, gain stability is crucial, especially for high-altitude and long-distance communication needs. The low-profile ultra-wideband antenna array of the present invention has high gain stability, which can meet the high-altitude and long-distance communication needs of satellite communications, and the 10-31GHz frequency band coverage meets the satellite communication system's requirements for multiple frequency bands such as the Ku band and the Ka band, achieving good broadband coverage and impedance matching performance.

[0034] In summary, the low-profile ultra-wideband antenna array of the present invention performs excellently in frequency band coverage, impedance matching, signal gain and simulation consistency, completely covers the Ku band and K band, is suitable for the low-profile and multi-band requirements of modern satellite communications, and is an efficient, stable satellite communication antenna solution with multiple application potentials.

Claims

1. A low-profile ultra-wideband antenna array, comprising a feed network and a radiation network, characterized in that The feeding network is implemented based on a suspended microstrip line structure, the radiating network is implemented using a double-ridge waveguide horn structure with four-level transition, a transmission network is arranged between the feeding network and the radiating network, the transmission network is implemented based on a horn coupling slot structure and a curved coupling slot structure, the feeding network is used to couple with the curved coupling slot structure in the transmission network, and an external radio frequency signal is fed into the transmission network using a suspended microstrip line feeding method, the horn coupling slot structure in the transmission network is used to couple with the radiating network, and the radio frequency signal fed into it by the feeding network is transmitted to the radiating network, and the radiating network is used to radiate the radio frequency signal transmitted thereto into free space.

2. A low-profile ultra-wideband antenna array according to claim 1, characterized in that The radiation network includes a first metal plate and 32 radiation units arranged on the first metal plate, the length of the first metal plate is greater than its width, the length direction of the first metal plate is defined as the front-to-back direction, the width direction is defined as the left-to-right direction, and the height direction is defined as the up-down direction, the 32 radiation units are evenly spaced in 4 rows and 8 columns to form a radiation array, the row direction of the radiation array is along the front-to-back direction, and the column direction is along the left-to-right direction; Each radiation unit includes a first hollow slot, a second hollow slot, two four-stage transition double-ridge waveguide horns and a metal partition; the first hollow slot and the second hollow slot are both opened on the first metal plate, and the two are connected up and down to penetrate the first metal plate up and down, the first hollow slot and the second hollow slot are both rectangular structures, and their length directions are along the front-to-back direction, the width directions are along the left-to-right direction, and the height directions are along the up-down direction. The upper end face of the first hollow slot is flush with the upper end face of the first metal plate, and the lower end face of the second hollow slot is flush with the The lower end surface of the first metal plate is flush, the upper end surface of the second hollow groove is in a state of being in contact with the lower end surface of the first hollow groove, the central axis of the first hollow groove and the second hollow groove along the up-down direction are located in the same straight line, the length of the second hollow groove is smaller than the length of the first hollow groove, the width of the second hollow groove is smaller than the width of the first hollow groove, the plane that makes the first hollow groove bilaterally symmetrical is called the first symmetry plane of the radiation unit, and the plane that makes the first hollow groove front-back symmetrical is called the second symmetry plane of the radiation unit;The metal partition is located in the second hollow groove, the height direction of the metal partition is along the up-down direction, the length direction is along the front-to-back direction, the width is along the left-to-right direction, and its length is smaller than its width, the upper end face of the metal partition is flush with the upper end face of the second hollow groove, the lower end face of the metal partition is flush with the lower end face of the second hollow groove, the left end face of the metal partition is connected to the left end face of the second hollow groove and is in a fitted state, the right end face of the metal partition is connected to the right end face of the second hollow groove and is in a fitted state, the distance from the front end face of the metal partition to the front end face of the second hollow groove is equal to the distance from the rear end face of the metal partition to the rear end face of the second hollow groove, A third hollow groove is provided in the metal partition, and the third hollow groove is a rectangular parallelepiped structure. The length direction of the third hollow groove is along the front-to-back direction, the width direction is along the left-to-right direction, and the height direction is along the up-down direction. The upper end face of the third hollow groove is flush with the upper end face of the metal partition, the front end face of the third hollow groove is flush with the front end face of the metal partition, and the rear end face of the third hollow groove is flush with the rear end face of the metal partition. The height of the third hollow groove is less than the height of the metal partition, and the width of the third hollow groove is less than the width of the metal partition. The third hollow groove is left-right symmetrical about the first symmetry plane of the radiation unit, and the two four-stage transition double-ridge waveguide horns are respectively referred to as the first A four-level transition double-ridge waveguide horn and a second four-level transition double-ridge waveguide horn, the first four-level transition double-ridge waveguide horn includes a first waveguide step and a second waveguide step, the first waveguide step is arranged in the first hollow groove and the second hollow groove, and is located on the front side of the metal partition, the first waveguide step includes a connecting block, a first step, a second step, a third step and a fourth step, the connecting block, the first step, the second step, the third step and the fourth step are all rectangular structures, and the length direction is along the front-to-back direction, the width direction is along the left-right direction, and the height direction is along the up-down direction, the first step, the second step, the third step The lengths of the ladder and the fourth step are both smaller than their widths; the left end face of the connecting block is flush with the left end face of the first hollow groove, the right end face of the connecting block is flush with the left end face of the second hollow groove, the upper end face of the connecting block is flush with the upper end face of the first hollow groove, the lower end face of the connecting block is flush with the lower end face of the first hollow groove, there is a distance between the front end face of the connecting block and the front end face of the first hollow groove, there is a distance between the rear end face of the connecting block and the front end face of the metal partition, and the distance between the front end face of the connecting block and the front end face of the first hollow groove is equal to the distance between the rear end face of the connecting block and the front end face of the metal partition;The first step is located on the right side of the connecting block, the left end face of the first step is connected to the right end face of the connecting block and is in a fitted state, the upper end face of the first step is flush with the upper end face of the connecting block, the front end face of the first step is flush with the front end face of the connecting block, and the rear end face of the first step is flush with the rear end face of the connecting block. The second step is located below the first step, the upper end face of the second step is connected to the lower end face of the first step and is in a fitted state, the left end face of the second step is flush with the left end face of the first step, and the front end face of the second step is flush with the The front end face of the ladder is flush, the rear end face of the second step is flush with the rear end face of the first step, the width of the second step is greater than the width of the first step, the lower end face of the second step is located on the upper side of the lower end face of the first hollow groove, and there is a distance between the two, the third step is located below the second step, the upper end face of the third step is connected to the lower end face of the second step and is in a fitted state, the left end face of the third step is flush with the left end face of the second step, the front end face of the third step is flush with the front end face of the second step, and the rear end face of the third step is flush with the The rear end surface of the ladder is flush, the width of the third step is greater than the width of the second step, the lower end surface of the third step is located at the lower side of the lower end surface of the first hollow groove, and there is a distance between the two, the fourth step is located below the third step, the upper end surface of the fourth step is connected to the lower end surface of the third step and is in a fitted state, the left end surface of the fourth step is flush with the left end surface of the third step, the front end surface of the fourth step is flush with the front end surface of the third step, the rear end surface of the fourth step is flush with the rear end surface of the third step, and the width of the fourth step is greater than the width of the third step The width of the step, the lower end face of the fourth step is flush with the lower end face of the second hollow groove, the right end face of the fourth step is located on the left side of the first symmetry plane of the radiation unit, and there is a distance between the two; the second waveguide step is located on the right side of the first symmetry plane of the radiation unit and on the front side of the second symmetry plane of the radiation unit, the first waveguide step and the second waveguide step are symmetrical about the first symmetry plane of the radiation unit, the second four-level transition double-ridge waveguide horn is located on the rear side of the second symmetry plane of the radiation unit, and the first four-level transition double-ridge waveguide horn and the second four-level transition double-ridge waveguide horn are symmetrical about the second symmetry plane of the radiation unit. ; 3. A low-profile ultra-wideband antenna array according to claim 2, characterized in that The transmission network includes a metal patch and 32 transmission units arranged on the metal patch, the metal patch is located below the first metal plate, and its upper surface is in contact with the lower surface of the first metal plate, the metal patch is a rectangular structure, its length is along the front-to-back direction, its width is along the left-to-right direction, and its height is along the up-down direction, the front end face of the metal patch is flush with the front end face of the first metal plate, the rear end face of the metal patch is flush with the rear end face of the first metal plate, the left end face of the metal patch is flush with the left end face of the first metal plate, and the right end face of the metal patch is flush with the right end face of the first metal plate; Each transmission unit is realized by slotting on the metal patch, and each transmission unit includes a fourth hollow slot and a fifth hollow slot. The fourth hollow slot includes a first rectangular slot, an isosceles trapezoidal slot, a second rectangular slot, a curved slot and a third rectangular slot arranged in sequence from front to back. The first rectangular slot, the isosceles trapezoidal slot, the second rectangular slot, the curved slot and the third rectangular slot all penetrate the metal patch from top to bottom. The length directions of the first rectangular slot, the second rectangular slot and the third rectangular slot are all along the left-right direction, and the width directions of the first rectangular slot, the second rectangular slot and the third rectangular slot are all along the front-back direction. The lower base of the isosceles trapezoidal slot is located in front of its upper base and is along the left-right direction. The first rectangular groove, the isosceles trapezoidal groove, the second rectangular groove and the third rectangular groove are symmetrical about the same plane. The length of the first rectangular groove is greater than the length of the lower base of the isosceles trapezoidal groove, and the length of the upper base of the isosceles trapezoidal groove is equal to the length of the second rectangular groove. The curved groove is formed by connecting the first arc surface, the first plane, the second arc surface and the second plane in sequence. The first arc surface and the second arc surface are both convex to the front side, and the two have different centers. The first plane and the second plane are located on the same vertical plane, and the first plane is located on the left side of the second plane. The first rectangular groove, the isosceles trapezoidal groove, the second rectangular groove and the curved groove are connected in sequence from the front. The third rectangular groove is located in the On the rear side of the first plane of the curved groove, the front end face of the third rectangular groove is connected to the first plane of the curved groove, and the two completely overlap; the fifth hollow groove is located on the rear side of the fourth hollow groove, with a distance between the two, and the fourth hollow groove and the fifth hollow groove are symmetrical front to back about a certain plane; 32 transmission units correspond to 32 radiation units one by one, and in a corresponding transmission unit and a radiation unit, the fourth hollow groove and the fifth hollow groove of the transmission unit are symmetrical front to back about the second symmetry plane of the radiation unit, the first rectangular groove, the isosceles trapezoidal groove, the second rectangular groove and the third rectangular groove of the fourth hollow groove of the transmission unit are symmetrical left to right about the first symmetry plane of the radiation unit, and the bending of the fourth hollow groove of the transmission unit The first plane and the second plane of the curved groove are symmetrical about the first symmetry plane of the radiation unit, the rear end face of the third rectangular groove of the fourth hollow groove of the transmission unit and the front end face of the metal partition of the radiation unit are located in the same plane, the left end face of the third rectangular groove of the fourth hollow groove of the transmission unit is located on the left side of the left end face of the third hollow groove of the radiation unit, and the right end face of the third rectangular groove of the fourth hollow groove of the transmission unit is located on the right side of the left end face of the third hollow groove of the radiation unit; when a corresponding transmission unit and a radiation unit radiate to the same plane along the up and down directions, the first rectangular groove of the fourth hollow groove of the transmission unit is located between the first waveguide step and the second waveguide step of the first four-level transition double-ridge waveguide horn of the radiation unit, connecting the two.

4. A low-profile ultra-wideband antenna array according to claim 3, characterized in that The feeding network includes a second metal plate, an electromagnetic bandgap structure, a one-to-thirty-two power distribution network and a metal coaxial probe. The second metal plate is located below the metal patch, and its upper surface is at a distance from the lower surface of the metal patch. The second metal plate is a rectangular parallelepiped structure with a length along the front-to-back direction, a width along the left-to-right direction, and a height along the up-down direction. The front end face of the second metal plate is flush with the front end face of the metal patch, the rear end face of the second metal plate is flush with the rear end face of the metal patch, the left end face of the second metal plate is flush with the left end face of the metal patch, and the right end face of the second metal plate is flush with the right end face of the metal patch. The second metal plate is provided with a gap matching the contour of the one-to-thirty-two power distribution network, and the gap runs through the second metal plate from top to bottom. The one-to-thirty-two power distribution network is formed by arranging a microstrip line in the gap. The one-to-thirty-two power distribution network has an input end and 32 output ends, and the 32 output ends of the one-to-thirty-two power distribution network correspond one-to-one to the 32 transmission units. The input end of the one-to-thirty-two power distribution network is connected to the metal coaxial probe, and the input end of the one-to-thirty-two power distribution network is connected to the external radio frequency signal through the metal coaxial probe. The one-to-thirty-two power distribution network is used to divide the external radio frequency signal connected to its input end into 32 radio frequency signals and couple and feed them into the curved groove of the fourth hollow groove of the 32 transmission units and the curved groove of the fifth hollow groove symmetrical to the curved groove of the fourth hollow groove through its 32 output ends. When the curved groove of the fourth hollow groove of a certain transmission unit When the RF signal is fed into the fifth hollow groove at a position symmetrical to the curved groove of the fourth hollow groove, the RF signal at the curved groove of the fourth hollow groove of the transmission unit is transmitted to the first rectangular groove of the fourth hollow groove of the transmission unit, and then fed into between the first waveguide step and the second waveguide step of the first four-level transition double-ridge waveguide horn of the radiation unit corresponding to the transmission unit, the RF signal at a position symmetrical to the curved groove of the fourth hollow groove of the transmission unit in the fifth hollow groove of the transmission unit is transmitted to a position symmetrical to the first rectangular groove of the fourth hollow groove in the fifth hollow groove of the transmission unit, and then fed into the second four-level transition double-ridge waveguide horn of the radiation unit corresponding to the transmission unit; the electromagnetic band gap structure is composed of a plurality of metal cylinders, the axes of the plurality of metal cylinders are all along the up-down direction, and the lower end faces thereof are all fixed and in a fit with the upper end face of the second metal plate, and the upper end faces thereof are all fixed and in a fit with the lower end face of the metal patch; the plurality of metal cylinders are distributed around the gap to prevent electromagnetic leakage.

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