A low-profile ultrawideband antenna array

Abstract

This invention discloses a low-profile ultra-wideband antenna array, comprising a feeding network and a radiating network. The feeding network is implemented based on a suspended microstrip line structure, and the radiating network is implemented using a four-stage transition double-ridge waveguide horn structure. A transmission network is provided 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, feeding external radio frequency signals 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, transmitting the radio frequency signals fed into it by the feeding network to the radiating network. The radiating network is used to radiate the radio frequency signals transmitted thereto into free space. The advantage is that while having a low profile, it can also operate in the 10-31 GHz satellite communication band, completely covering the Ku-band and K-band, achieving low profile and ultra-wideband compatibility in satellite communication systems.

Description

Technical Field

[0001] This invention relates to ultra-wideband antenna arrays, and more particularly to a low-profile ultra-wideband antenna array. Background Technology

[0002] With the development of satellite communication systems towards multifunctionality and high integration, the space required for antennas, as core components of satellite communication systems, is gradually shrinking, while the requirements for operating bandwidth are also constantly 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 transmit / reflect array antenna [J]. Solid State Electronics Research and Progress, 2024, 44(02):138-142." proposes a space-fed broadband array antenna with high gain and low profile, and its operating bandwidth is 18-27 GHz. 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. By designing the contours of the four parasitic patches and dipole arms as curves, the impedance bandwidth is broadened. At the same time, the profile height is reduced by replacing the traditional metal back cavity in the dielectric substrate with metallized vias. Its operating bandwidth is 15.5-23.5 GHz. Although the antenna arrays proposed in References [1] and [2] have achieved low-profile characteristics, the use of metallized vias or specific parasitic structures also limits the propagation path of electromagnetic waves. The impedance matching of ultra-wideband cannot be achieved, resulting in the bandwidth not being able to be further extended. It can only cover part of the Ku-band and part of the K-band. It is difficult to achieve compatibility between ultra-wideband and low profile in satellite communication systems at the same time. 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 10-31GHz satellite communication frequency band while having a low profile, fully covering the Ku-band and K-band, and realizing low profile and ultra-wideband compatibility in satellite communication systems.

[0004] The technical solution adopted by this invention to solve the above-mentioned technical problems is as follows: a low-profile ultra-wideband antenna array, comprising a feeding network and a radiating network. The feeding network is implemented based on a suspended microstrip line structure, and the radiating network is implemented using a four-stage transition double-ridge waveguide horn structure. A transmission network is provided 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, feeding external radio frequency signals 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, transmitting the radio frequency signals fed into it by the feeding network to the radiating network. The radiating network is used to radiate the radio frequency signals transmitted thereto into free space.

[0005] Compared with existing technologies, the advantages of this invention lie in realizing the feed network based on a suspended microstrip line structure. The suspended microstrip line structure effectively reduces the transmission loss of the feed network and improves the stability of signal transmission. Simultaneously, it makes the overall design of the feed network more compact and reduces the cross-section. A transmission network is set between the feed network and the radiating network. The transmission network is implemented based on a horn coupling slot structure and a curved coupling slot structure. The transmission network couples with the feed network through its internal curved coupling slot structure and with the radiating network through the horn coupling slot structure, transmitting the radio frequency signal from the feed network to the radiating network, thus enhancing the strength of the radio frequency signal and reducing its... To reduce losses and expand the operating bandwidth, a radiation network is implemented based on a four-stage transition double-ridged waveguide horn structure. The characteristics of the double-ridged waveguide horn structure are optimized step-by-step by adjusting the characteristics of the four-stage transition region, allowing the impedance of the double-ridged waveguide horn structure to transition gradually, thereby achieving smooth impedance matching within the ultra-wideband. Simultaneously, the double-ridged waveguide horn structure improves the radiation efficiency of RF signals without increasing the antenna's vertical height. Therefore, this invention achieves both low profile and ultra-wideband characteristics, covering the 10-31 GHz satellite communication frequency band, encompassing the complete Ku-band and the complete k-band, 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 disposed 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-back direction, the width direction as the left-right direction, and the height direction as the up-down direction. The 32 radiation units are evenly distributed in 4 rows and 8 columns to form a radiation array. The row direction of the radiation array is along the front-back direction, and the column direction is along the left-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 formed on the first metal plate and are vertically connected, penetrating the first metal plate from top to bottom. Both the first hollow slot and the second hollow slot are cuboid structures. The structure consists of a first hollow groove, a second hollow groove, and a third hollow groove. The second hollow groove is flush with the first metal plate, and the third hollow groove is flush with the first metal plate. The upper surface of the second hollow groove is in contact with the lower surface of the first hollow groove. The central axes of the first and second hollow grooves along the vertical direction are on the same straight line. The length of the second hollow groove is less than the length of the first hollow groove, and the width of the second hollow groove is less than the width of the first hollow groove. The plane that makes the first hollow groove symmetrical from left to right is called the first symmetry plane of the radiation unit, and the plane that makes the first hollow groove symmetrical from front to back is called the second symmetry plane of the radiation unit.The metal partition is located within the second hollowed-out groove. The height of the metal partition is vertical, its length is horizontal, and its width is horizontal, with its length less than its width. The upper and lower surfaces of the metal partition are flush with the upper and lower surfaces of the second hollowed-out groove. The left and right surfaces of the metal partition are connected to and fitted with the left and right surfaces of the second hollowed-out groove. The distance from the front surface of the metal partition to the front surface of the second hollowed-out groove is equal to the distance from the rear surface of the metal partition to the rear surface of the second hollowed-out groove. The metal partition described herein has a third hollow slot, which is a cuboid structure. The length of the third hollow slot is along the front-to-back direction, the width is along the left-to-right direction, and the height is along the top-to-bottom direction. The upper end face, front end face, and rear end face of the third hollow slot are flush with the upper end face of the metal partition. The height and width of the third hollow slot are less than the height and width of the metal partition. The third hollow slot is symmetrical about the first plane of symmetry of the radiating unit. The two four-stage transition double-ridge waveguide horns are respectively referred to as the first... The fourth-stage transition double-ridge waveguide horn and the second fourth-stage transition double-ridge waveguide horn are described. The first fourth-stage transition double-ridge waveguide horn includes a first waveguide step and a second waveguide step. The first waveguide step is disposed within the first and second hollow slots and is located on the front side of the metal partition. The first waveguide step includes a connecting block, a first-level step, a second-level step, a third-level step, and a fourth-level step. The connecting block, the first-level step, the second-level step, the third-level step, and the fourth-level step are all cuboid structures, with their length direction along the front-back direction, their width direction along the left-right direction, and their height direction along the up-down direction. The first-level step, the second-level step, the third-level step, the fourth-level step... The length of the ladder and the fourth step is less than their width; 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 to the right of the connecting block. The left end face of the first step is connected to and fitted against the right end face of the connecting block. 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. 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 and fitted against the lower end face of the first step. The left end face of the second step is flush with the left end face of the first step. The front end face of the second step is flush with the right end face of the first step. The front face of the first step is flush with the front face of the second step, and the rear face of the second step is flush with the rear face of the first step. The width of the second step is greater than the width of the first step. The lower face of the second step is located above the lower face of the first hollowed-out groove, and there is a distance between them. The third step is located below the second step. The upper face of the third step is connected to and fits against the lower face of the second step. The left face of the third step is flush with the left face of the second step. The front face of the third step is flush with the front face of the second step. The rear face of the third step is flush with the rear face of the second step. The rear end face of the ladder is flush with the front end face. The width of the third step is greater than the width of the second step. The lower end face of the third step is located below the lower end face of the first hollowed-out groove, and there is a distance between them. The fourth step is located below the third step. The upper end face of the fourth step is connected to and fits against the lower end face of the third step. The left end face of the fourth step is flush with the left end face of the third step. The front end face of the fourth step is flush with the front end face of the third step. The rear end face of the fourth step is flush with the rear end face of the third step. The width of the fourth step is greater than that of the third step. The width of the steps is such that the lower end face of the fourth step is flush with the lower end face of the second hollowed-out groove, and the right end face of the fourth step is located to the left of the first symmetry plane of the radiating unit, with a distance between them; the second waveguide step is located to the right of the first symmetry plane of the radiating unit and to the front of the second symmetry plane of the radiating unit, and the first and second waveguide steps are symmetrical about the first symmetry plane of the radiating unit; the second four-stage transition double-ridge waveguide horn is located to the rear of the second symmetry plane of the radiating unit, and the first and second four-stage transition double-ridge waveguide horns are symmetrical about the second symmetry plane of the radiating unit.

[0007] Furthermore, the transmission network includes a metal patch and 32 transmission units disposed 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 has a cuboid structure, with its length along the front-to-back direction, its width along the left-to-right direction, and its height along the top-to-bottom 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, and the left end face of the metal patch is flush with the left end face of the first metal plate. The right end face is flush with the right end face of the first metal plate; each transmission unit is implemented by slotting the metal patch, and each transmission unit includes a fourth cutout slot and a fifth cutout slot. The fourth cutout slot includes a first rectangular slot, an isosceles trapezoidal slot, a second rectangular slot, a curved slot, and a third rectangular slot arranged sequentially 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 vertically. The length direction of the first rectangular slot, the second rectangular slot, and the third rectangular slot is along the left-right direction. The width directions of the first rectangular 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 is along the left-to-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 along the front-to-back direction. The front protrusion is different from the center of the two circles. The first plane and the second plane are located on the same vertical plane. The first plane is located to the left 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 front to back. The third rectangular groove is located behind 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 behind the fourth hollow groove. There is a distance between the two. The fourth hollow groove and the fifth hollow groove are symmetrical about a certain plane.There is a one-to-one correspondence between the 32 transmission units and the 32 radiation units. Within each corresponding transmission unit and radiation unit, the fourth and fifth hollow slots of the transmission unit are symmetrical about the second symmetry plane of the radiation unit. The first rectangular slot, isosceles trapezoidal slot, second rectangular slot, and third rectangular slot of the fourth hollow slot of the transmission unit are symmetrical about the first symmetry plane of the radiation unit. The first and second planes of the curved slot of the fourth hollow slot of the transmission unit are symmetrical about the first symmetry plane of the radiation unit. The rear end face of the third rectangular slot of the fourth hollow slot of the transmission unit is symmetrical about the first symmetry plane of the radiation unit. The front ends of the metal partitions of the radiating unit are on the same plane. The left end face of the third rectangular slot of the fourth hollow slot of the transmission unit is located to the left of the left end face of the third hollow slot of the radiating unit, and the right end face of the third rectangular slot of the fourth hollow slot of the transmission unit is located to the right of the left end face of the third hollow slot of the radiating unit. When a corresponding transmission unit and a radiating unit radiate to the same plane in the vertical direction, the first rectangular slot of the fourth hollow slot of the transmission unit is located between the first waveguide step and the second waveguide step of the first four-stage transition double-ridge waveguide horn of the radiating unit, connecting the two.

[0008] Furthermore, the power supply network includes a second metal plate, an electromagnetic bandgap structure, a 1-to-32 power distribution network, and a metal coaxial probe. The second metal plate is located below the metal patch, and its upper surface is a distance from the lower surface of the metal patch. The second metal plate has a cuboid structure, with its length along the front-to-back direction, its width along the left-to-right direction, and its height along the top-to-bottom 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... The surface is flush with the right end face of the metal patch; a slot matching the outline of the 1 / 32 power distribution network is formed on the second metal plate, and the slot extends vertically through the second metal plate. The 1 / 32 power distribution network is formed by setting microstrip lines within the slot. The 1 / 32 power distribution network has one input terminal and 32 output terminals, and each of the 32 output terminals corresponds to one of the 32 transmission units. The input terminal of the 1 / 32 power distribution network is connected to the metal coaxial probe, and the input terminal of the 1 / 32 power distribution network is connected to the metal coaxial probe. The external radio frequency (RF) signal, as described in the 1-to-32 power distribution network, is used to divide the external RF signal input to its input terminal into 32 equal RF signals. These signals are then coupled one-to-one through its 32 output terminals and fed into the curved slots of the fourth and fifth slots of the 32 transmission units, at locations symmetrical to the curved slots of the fourth slot. When an RF signal is fed into the curved slot of the fourth slot and the fifth slot of a transmission unit at a location symmetrical to the curved slot of the fourth slot, the RF signal at the curved slot of that transmission unit is transmitted to the first rectangular slot of the fourth slot of that transmission unit, and then fed into the first fourth-stage transition double-ridge waveguide horn of the radiation unit corresponding to that transmission unit. Between the first and second waveguide steps, the radio frequency signal at the symmetrical location of the curved groove in the fifth slot of the transmission unit and the fourth slot is transmitted to the symmetrical location of the first rectangular groove in the fifth slot of the transmission unit and the fourth slot, and then fed into the second and fourth stage transition double-ridge waveguide horn of the radiation unit corresponding to the transmission unit; the electromagnetic bandgap structure is composed of multiple metal cylinders, the axes of the multiple metal cylinders are all along the vertical direction, and their lower end faces are all fixed and in contact with the upper end face of the second metal plate, and their upper end faces are all fixed and in contact with the lower end face of the metal patch; the multiple metal cylinders are distributed around the gap to prevent electromagnetic leakage. Attached Figure Description

[0009] Figure 1 This is an exploded view of the low-profile ultra-wideband antenna array of the present invention.

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

[0011] Figure 3 This is an overall perspective view of a single radiating element of the low-profile ultra-wideband antenna array of the present invention.

[0012] Figure 4 This is a partial perspective view of a single radiating element of the low-profile ultra-wideband antenna array of the present invention.

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

[0014] Figure 6 This is a perspective view of the metal partition of the low-profile ultra-wideband antenna array of the present invention.

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

[0016] Figure 8 This is an overall structural diagram of the transmission network of the low-profile ultra-wideband antenna array of the present invention.

[0017] Figure 9 This is a perspective view of a single transmission element of the low-profile ultra-wideband antenna array of the present invention.

[0018] Figure 10 This is a structural diagram of the feed network for the low-profile ultra-wideband antenna array of the present invention;

[0019] Figure 11 This is a perspective view of the electromagnetic bandgap of the low-profile ultra-wideband antenna array of the present invention.

[0020] Figure 12 This is a perspective view of the 1 to 32 power distribution network of the low-profile ultra-wideband antenna array of the present invention.

[0021] Figure 13 This is a perspective view of the metal coaxial probe of the low-profile ultra-wideband antenna array of the present invention.

[0022] Figure 14 This is a front view of the feed network of the low-profile ultra-wideband antenna array of the present invention.

[0023] Figure 15 This is a diagram showing the return loss characteristics of the low-profile ultra-wideband antenna array of the present invention. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0025] Example 1: As Figure 1 As shown, a low-profile ultra-wideband antenna array includes a feeding network 1 and a radiating network 2. The feeding network 1 is implemented based on a suspended microstrip line structure, and the radiating network 2 is implemented using a four-stage transition double-ridge waveguide horn structure. A transmission network 3 is provided between the feeding network 1 and the radiating network 2. 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, feeding external radio frequency signals 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, transmitting the radio frequency signals fed into it by the feeding network 1 to the radiating network 2. The radiating network 2 is used to radiate the radio frequency signals transmitted thereto into free space.

[0026] In this embodiment, the feed network 1 is implemented based on a suspended microstrip line structure. The suspended microstrip line structure effectively reduces the transmission loss of the feed network 1 and improves the stability of signal transmission. At the same time, it makes the overall design of the feed network 1 more compact and reduces the cross-section. A transmission network 3 is set between the feed network 1 and the radiation network 2. The transmission network 3 is implemented based on a horn coupling slot structure and a curved coupling slot structure. The transmission network 3 couples with the feed network 1 through its internal curved coupling slot structure and couples with the radiation network 2 through the horn coupling slot structure, transmitting the radio frequency signal from the feed network 1 to the radiation network 2, enhancing the strength of the radio frequency signal, reducing its loss, and expanding the operating bandwidth. The radiation network 2 is implemented based on a four-stage transition double-ridge waveguide horn structure. The characteristics of the double-ridge waveguide horn structure are adjusted step by step through the four-stage transition region to optimize the impedance of the double-ridge waveguide horn structure step by step, thereby achieving smooth impedance matching in the ultra-wideband. At the same time, the double-ridge waveguide horn structure improves the radiation efficiency of the radio frequency signal without increasing the vertical height of the antenna.

[0027] Example 2: This example is basically the same as Example 1, except that: in this example, as Figures 2 to 7As shown, the radiation network 2 includes a first metal plate 4 and 32 radiation units 5 disposed 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-back direction, the width direction as the left-right direction, and the height direction as the up-down direction. The 32 radiation units 5 are evenly distributed in 4 rows and 8 columns to form a radiation array. The row direction of the radiation array is along the front-back direction, and the column direction is along the left-right direction. Each radiation unit 5 includes a first hollow slot 6, a second hollow slot 7, two four-stage transition double-ridge waveguide horns, and a metal partition 8. The first hollow slot 6 and the second hollow slot 7 are both formed on the first metal plate 4, and they are vertically connected, passing through the first metal plate 4 vertically. The first hollow slot 6 and the second hollow slot 7 are both... The structure is a cuboid, with its length along the front-to-back direction, its width along the left-to-right direction, and its height along the up-to-down direction. The upper end face of the first hollow groove 6 is flush with the upper end face of the first metal plate 4, and the lower end face of the second hollow groove 7 is flush with the lower end face of the first metal plate 4. The upper end face of the second hollow groove 7 is in contact with the lower end face of the first hollow groove 6. The central axes of the first hollow groove 6 and the second hollow groove 7 along the up-to-down direction are located on 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 from left to right is called the first symmetry plane of the radiation unit 5, and the plane that makes the first hollow groove 6 symmetrical from front to back is called the second symmetry plane of the radiation unit 5.The metal partition 8 is located within the second hollowed-out groove 7. The height of the metal partition 8 is along the vertical direction, the length along the front-back direction, and the width along the left-right direction, with its length being less than its width. The upper and lower ends of the metal partition 8 are flush with the upper and lower ends of the second hollowed-out groove 7. The left and right ends of the metal partition 8 are connected to and fitted with the left and right ends of the second hollowed-out groove 7. The distance from the front end of the metal partition 8 to the front end of the second hollowed-out groove 7 is equal to the distance from the rear end of the metal partition 8 to the rear end of the second hollowed-out groove 7. A third hollowed-out groove is formed in the metal partition 8. The third hollow slot 9 is a cuboid structure. The length of the third hollow slot 9 is along the front-to-back direction, the width is along the left-to-right direction, and the height is along the top-to-bottom 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 radiating unit 5. The two fourth-stage transition double-ridge waveguide horns are respectively called the first fourth-stage transition double-ridge waveguide horn 10 and the second fourth-stage transition double-ridge waveguide horn 10. The first four-stage transition double-ridged waveguide horn 10 includes a first waveguide step 12 and a second waveguide step 13. The first waveguide step 12 is disposed within the first hollow slot 6 and the second hollow slot 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-level step 15, a second-level step 16, a third-level step 17, and a fourth-level step 18. The connecting block 14, the first-level step 15, the second-level step 16, the third-level step 17, and the fourth-level step 18 are all cuboid structures, with their length direction along the front-back direction, their width direction along the left-right direction, and their height direction along the up-down direction. The first-level step 15, the second-level step 16... The lengths of the third step 17 and the fourth step 18 are both less 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 to the right of the connecting block 14. The left end face of the first step 15 is connected to and in contact with the right end face of the connecting block 14. 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. The rear end face of the first step 15 is flush with the rear end face of the connecting block 14. The second step 16 is located below the first step 15. The upper end face of the second step 16 is connected to and in contact with the lower end face of the first step 15. The left end face of the second step 16 is flush with the left end face of the first step 15. 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 above the lower end face of the first hollow groove 6, and there is a distance between them. The third step 17 is located below the second step 16. The upper end face of the third step 17 is connected to and fits against the lower end face of the second step 16. 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. 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 face of the third step 17 is located below the lower end face of the first hollow groove 6, and there is a distance between them. The fourth step 18 is located below the third step 17. The upper end face of the fourth step 18 is connected to and fits against the lower end face of the third step 17. The left end face of the fourth step 18 is flush with the left end face of the third step 17. The front end face of the fourth step 18 is flush with the front end face of the third step 17. The rear end face of the fourth step 18 is flush with the rear end face of the third step 17. The width of the fourth step 18 is greater than the width of the third step 17. The lower end face of step 18 is flush with the lower end face of the second hollowed-out groove 7. The right end face of the fourth step 18 is located to the left of the first symmetry plane of the radiating unit 5, and there is a distance between them. The second waveguide step 13 is located to the right of the first symmetry plane of the radiating unit 5 and to the front of the second symmetry plane of the radiating unit 5. The first waveguide step 12 and the second waveguide step 13 are symmetrical about the first symmetry plane of the radiating unit 5. The second fourth-stage transition double-ridge waveguide horn 11 is located to the rear of the second symmetry plane of the radiating unit 5. The first fourth-stage transition double-ridge waveguide horn 10 and the second fourth-stage transition double-ridge waveguide horn 11 are symmetrical about the second symmetry plane of the radiating unit 5.

[0028] In this embodiment, the radiation network 2 is realized based on a four-stage transition double-ridge waveguide horn structure. The four-stage transition double-ridge waveguide horn structure is realized based on the first four-stage transition double-ridge waveguide horn 10 and the second four-stage transition double-ridge waveguide horn 11. The first four-stage transition double-ridge 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 connected and fixed to the first metal plate 4 through the connecting block 14. The double-ridge waveguide horn structure is optimized and adjusted step by step through the four steps: the fourth step 18, the third step 17, the second step 16, and the first step 15. The ridge waveguide horn structure's characteristics allow for a gradual impedance transition, achieving smooth impedance matching within the ultra-wideband. This enables the transmission network 3 to feed the RF signal into the first four-stage transition double-ridge waveguide horn 10 (between the first waveguide step 12 and the second waveguide step 13), allowing it to radiate smoothly from the radiation network 2 into free space. Similarly, when the transmission network 3 feeds the RF signal into the second four-stage transition double-ridge waveguide horn 11, it can also radiate smoothly from the radiation network 2 into free space. Both the first four-stage transition double-ridge waveguide horn 10 and the second four-stage transition double-ridge waveguide horn 11 employ a double-ridge waveguide horn structure, allowing the RF signal to diffuse outwards, thus improving the RF signal radiation efficiency without increasing the antenna's vertical height.

[0029] Example 3: This example is basically the same as Example 2, except that: in this example, as Figure 8 and Figure 9As shown, the transmission network 3 includes a metal patch 19 and 32 transmission units 20 disposed 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 has a cuboid structure, with its length along the front-to-back direction, its width along the left-to-right direction, and its 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 implemented by slotting on the metal patch 19. Each transmission unit 20 includes a fourth cutout slot 21 and a fifth cutout slot 22. The fourth cutout 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 sequentially 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 vertically. The length direction of the first rectangular slot 23, the second rectangular slot 25, and the third rectangular slot 27 is along the left-right direction. The width direction of the first rectangular slot 23, the second rectangular slot 25, and the third rectangular slot 27 is... Along the front-back direction, the lower base of the isosceles trapezoidal groove 24 is located in front of its upper base, and 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 formed by the sequential connection of the first arc surface 261, the first plane 262, the second arc surface 263, and the second plane 264. The first arc surface 261 and the second arc surface 263 both bulge forward, and they are not at their 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 to the left 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 front to back. The third rectangular groove 27 is located behind the first plane 262 of the curved groove 26. The front end face 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 behind the fourth hollow groove 21. There is a distance between the two. The fourth hollow groove 21 and the fifth hollow groove 22 are symmetrical about a certain plane.There is a one-to-one correspondence between the 32 transmission units 20 and the 32 radiation units 5. In a corresponding transmission unit 20 and radiation unit 5, the fourth hollow slot 21 and the fifth hollow slot 22 of the transmission unit 20 are symmetrical about the second plane of symmetry of the radiation unit 5. The first rectangular slot 23, the isosceles trapezoidal slot 24, the second rectangular slot 25, and the third rectangular slot 27 of the fourth hollow slot 21 of the transmission unit 20 are symmetrical about the first plane of symmetry of the radiation unit 5. The first plane 262 and the second plane 264 of the curved slot 26 of the fourth hollow slot 21 of the transmission unit 20 are symmetrical about the first plane of symmetry of the radiation unit 5. The third rectangular slot 27 of the fourth hollow slot 21 of the transmission unit 20... The rear end face of the transmission unit 20 is on the same plane as the front end face of the metal partition 8 of the radiating unit 5. The left end face of the third rectangular groove 27 of the fourth hollow groove 21 of the transmission unit 20 is located to the left of the left end face of the third hollow groove 9 of the radiating unit 5, and the right end face of the third rectangular groove 27 of the fourth hollow groove 21 of the transmission unit 20 is located to the right of the left end face of the third hollow groove 9 of the radiating unit 5. When a corresponding transmission unit 20 and a radiating unit 5 radiate to the same plane in the vertical direction, the first rectangular groove 23 of the fourth hollow groove 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 radiating unit 5, connecting the two.

[0030] In this embodiment, a transmission network 3 is implemented based on a metal patch 19 and 32 transmission units 20 disposed on the metal patch 19. Each transmission unit 20 includes a fourth cutout slot 21 and a fifth cutout slot 22. The fourth cutout slot 21 is implemented based on 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 and connected sequentially from front to back. The curved slot 26 and the third rectangular slot 27 form a curved coupling seam structure. The first rectangular slot 23, the isosceles trapezoidal slot 24, and the second rectangular slot 25 form a horn coupling gap structure. Since the fifth cutout slot 22 is symmetrical to the fourth cutout slot 21, there is also a curved coupling seam structure and a horn coupling gap structure in the fifth cutout slot 22. Therefore, each transmission unit 20 of the transmission network 3 has two horn coupling gap structures and two curved coupling gap structures. The two curved coupling gap structures are integrated as a whole. The power supply network 1 generates coupling, feeding the radio frequency (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 to it. The two horn coupling slot structures of each transmission unit 20 are coupled one-to-one with the first and second fourth-stage transition double-ridge waveguide horns 10 and 11 of a radiating unit, feeding the RF signal into the first and second fourth-stage transition double-ridge waveguide horns 10 and 11 of the radiating unit. The first and second fourth-stage transition double-ridge waveguide horns 10 and 11 of each radiating unit radiate the RF signal fed into them into free space. In the entire RF signal coupling and transmission process, horn structures are used in multiple places, thereby enhancing the strength of the RF signal, reducing its loss, and expanding the overall operating bandwidth.

[0031] Example 4: This example is basically the same as Example 3, except that: in this example, as Figure 10 and Figure 14As shown, the power supply network 1 includes a second metal plate 28, an electromagnetic bandgap structure 29, a 1-to-32 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 a distance away from the lower surface of the metal patch 19. The second metal plate 28 has a cuboid structure, with its length along the front-to-back direction, its width along the left-to-right direction, and its 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 plate 28 has a slot that matches the contour of the 1 / 32 power distribution network 30. This slot extends vertically through the second metal plate 28. The 1 / 32 power distribution network 30 is formed by placing microstrip lines within the slot. The 1 / 32 power distribution network 30 has one input terminal and 32 output terminals. Each of the 32 output terminals corresponds to one of the 32 transmission units 20. The input terminal of the 1 / 32 power distribution network 30 is connected to a metal coaxial probe 31, which receives an external radio frequency signal. The 1 / 32 power distribution network 30 is used to divide the external radio frequency signal received at its input terminal into 32 equal channels. Radio frequency (RF) signals are fed into the curved slots 26 and 5th slots 22 of the fourth slot 21 of the 32 transmission units 20 through their 32 output terminals, respectively, at the locations symmetrical to the curved slots 26 of the fourth slot 21. When an RF signal is fed into the location symmetrical to the curved slots 26 and 5th slots 22 of the fourth slot 21 of a certain transmission unit 20, the RF signal at the curved slot 26 of the fourth slot 21 of that transmission unit 20 is transmitted to the first rectangular slot 23 of the fourth slot 21 of that transmission unit 20, and then fed into the first waveguide step 12 and the second waveguide step of the first four-stage transition double-ridge waveguide horn 10 of the radiation unit 5 corresponding to that transmission unit 20. Between 13, the radio frequency signal at the symmetrical position of 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 symmetrical position of 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-stage transition double-ridge waveguide horn 11 of the radiation unit 5 corresponding to the transmission unit 20; the electromagnetic bandgap structure 29 is composed of multiple metal cylinders 32, the axes of the multiple metal cylinders 32 are all along the vertical direction, and their lower end faces are all fixed and in contact with the upper end face of the second metal plate 28, and their upper end faces are all fixed and in contact with the lower end face of the metal patch 19; the multiple metal cylinders 32 are distributed around the gap to prevent electromagnetic leakage.

[0032] 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 simulation and measured return loss characteristics of the low-profile ultra-wideband antenna array of the present invention are shown in Figure 15.

[0033] Figure 15 In this context, "Simulated" represents the simulation result, and "Mearsured" represents the actual test result. Analysis Figure 15 Simulation results show that the low-profile ultra-wideband antenna array of the present invention has a reflection coefficient (|S11|) of less than -10dB in the entire 10-31GHz frequency band, and even less 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 stable gain characteristics and small fluctuation amplitude throughout the entire frequency band. This shows that the low-profile ultra-wideband antenna array of the present invention can make the signal transmission more stable and effectively improve the reliability of the communication link. Figure 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. Gain stability is crucial for satellite communication, especially for high-altitude, long-distance communication needs. The low-profile ultra-wideband antenna array of the present invention has high gain stability, meeting the high-altitude, long-distance communication requirements of satellite communication. Furthermore, its 10-31 GHz frequency band coverage satisfies the needs of satellite communication systems for multiple frequency bands, including Ku-band and Ka-band, achieving excellent wideband coverage and impedance matching performance.

[0034] In summary, the low-profile ultra-wideband antenna array of this invention exhibits excellent performance in terms of bandwidth coverage, impedance matching, signal gain, and simulation consistency. It fully covers both the Ku and K bands and is suitable for the low-profile and multi-band requirements of modern satellite communications. It 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 radiating network, characterized in that... The feeding network is implemented based on a suspended microstrip line structure, and the radiating network is implemented using a four-stage transition double-ridge waveguide horn structure. A transmission network is provided 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 to feed external radio frequency signals 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 to transmit the radio frequency signals fed into it by the feeding network to the radiating network. The radiating network is used to radiate the radio frequency signals transmitted thereto into free space.

2. The 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 disposed 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-back direction, the width direction is defined as the left-right direction, and the height direction is defined as the up-down direction. The 32 radiation units are evenly distributed in 4 rows and 8 columns to form a radiation array. The row direction of the radiation array is along the front-back direction, and the column direction is along the left-right direction. Each radiating unit includes a first hollow slot, a second hollow slot, two four-stage transition double-ridge waveguide horns, and a metal partition. Both the first and second hollow slots are formed on the first metal plate, and are vertically connected, penetrating the first metal plate from top to bottom. Both the first and second hollow slots are cuboid structures, with their length along the front-to-back direction, their width along the left-to-right direction, and their height along the top-to-bottom direction. The upper surface of the first hollow slot is flush with the upper surface of the first metal plate, and the lower surface of the second hollow slot is flush with the upper surface of the first metal plate. The lower end face of the first metal plate is flush with the upper end face of the second hollow groove, and the upper end face of the second hollow groove is in contact with the lower end face of the first hollow groove. The central axes of the first hollow groove and the second hollow groove are located on the same straight line along the vertical direction. The length of the second hollow groove is less than the length of the first hollow groove, and the width of the second hollow groove is less than the width of the first hollow groove. The plane that makes the first hollow groove symmetrical from left to right is called the first symmetry plane of the radiation unit, and the plane that makes the first hollow groove symmetrical from front to back is called the second symmetry plane of the radiation unit.The metal partition is located within the second hollowed-out groove. The height of the metal partition is vertical, its length is horizontal, and its width is horizontal, with its length less than its width. The upper and lower surfaces of the metal partition are flush with the upper and lower surfaces of the second hollowed-out groove. The left and right surfaces of the metal partition are connected to and fitted with the left and right surfaces of the second hollowed-out groove. The distance from the front surface of the metal partition to the front surface of the second hollowed-out groove is equal to the distance from the rear surface of the metal partition to the rear surface of the second hollowed-out groove. The metal partition described herein has a third hollow slot, which is a cuboid structure. The length of the third hollow slot is along the front-to-back direction, the width is along the left-to-right direction, and the height is along the top-to-bottom direction. The upper end face, front end face, and rear end face of the third hollow slot are flush with the upper end face of the metal partition. The height and width of the third hollow slot are less than the height and width of the metal partition. The third hollow slot is symmetrical about the first plane of symmetry of the radiating unit. The two four-stage transition double-ridge waveguide horns are respectively referred to as the first... The fourth-stage transition double-ridge waveguide horn and the second fourth-stage transition double-ridge waveguide horn are described. The first fourth-stage transition double-ridge waveguide horn includes a first waveguide step and a second waveguide step. The first waveguide step is disposed within the first and second hollow slots and is located on the front side of the metal partition. The first waveguide step includes a connecting block, a first-level step, a second-level step, a third-level step, and a fourth-level step. The connecting block, the first-level step, the second-level step, the third-level step, and the fourth-level step are all cuboid structures, with their length direction along the front-back direction, their width direction along the left-right direction, and their height direction along the up-down direction. The first-level step, the second-level step, the third-level step, the fourth-level step... The length of the ladder and the fourth step is less than their width; 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 to the right of the connecting block. The left end face of the first step is connected to and fitted against the right end face of the connecting block. 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. 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 and fitted against the lower end face of the first step. The left end face of the second step is flush with the left end face of the first step. The front end face of the second step is flush with the right end face of the first step. The front face of the first step is flush with the front face of the second step, and the rear face of the second step is flush with the rear face of the first step. The width of the second step is greater than the width of the first step. The lower face of the second step is located above the lower face of the first hollowed-out groove, and there is a distance between them. The third step is located below the second step. The upper face of the third step is connected to and fits against the lower face of the second step. The left face of the third step is flush with the left face of the second step. The front face of the third step is flush with the front face of the second step. The rear face of the third step is flush with the rear face of the second step. The rear end face of the ladder is flush with the front end face. The width of the third step is greater than the width of the second step. The lower end face of the third step is located below the lower end face of the first hollowed-out groove, and there is a distance between them. The fourth step is located below the third step. The upper end face of the fourth step is connected to and fits against the lower end face of the third step. The left end face of the fourth step is flush with the left end face of the third step. The front end face of the fourth step is flush with the front end face of the third step. The rear end face of the fourth step is flush with the rear end face of the third step. The width of the fourth step is greater than that of the third step. The width of the steps is such that the lower end face of the fourth step is flush with the lower end face of the second hollowed-out groove, and the right end face of the fourth step is located to the left of the first symmetry plane of the radiating unit, with a distance between them; the second waveguide step is located to the right of the first symmetry plane of the radiating unit and to the front of the second symmetry plane of the radiating unit, and the first and second waveguide steps are symmetrical about the first symmetry plane of the radiating unit; the second four-stage transition double-ridge waveguide horn is located to the rear of the second symmetry plane of the radiating unit, and the first and second four-stage transition double-ridge waveguide horns are symmetrical about the second symmetry plane of the radiating 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 disposed 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 has a cuboid structure, with its length along the front-to-back direction, its width along the left-to-right direction, and its height 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 implemented by slotting the metal patch. Each transmission unit includes a fourth slot and a fifth slot. The fourth slot includes, from front to back, a first rectangular slot, an isosceles trapezoidal slot, a second rectangular slot, a curved slot, and a third rectangular slot. 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 vertically. The length of the first rectangular slot, the second rectangular slot, and the third rectangular slot is along the left-right direction, and the width of the first rectangular slot, the second rectangular slot, and the third rectangular slot is along the front-back direction. The lower base of the isosceles trapezoidal slot is located in front of its upper base and is also 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 a first arc surface, a first plane, a second arc surface, and a second plane in sequence. Both the first and second arc surfaces bulge forward and have different centers. The first and second planes are located on the same vertical plane, with the first plane located to the left of the second plane. The first rectangular groove, the isosceles trapezoidal groove, the second rectangular groove, and the curved groove are connected sequentially from front to back. The third rectangular groove is located within the... Behind 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 behind the fourth hollow groove, with a distance between them, and the fourth and fifth hollow grooves are symmetrical about a certain plane; 32 transmission units correspond one-to-one with 32 radiation units, and in a corresponding transmission unit and a radiation unit, the fourth and fifth hollow grooves of the transmission unit are symmetrical about the second symmetry plane of the radiation unit, and the first rectangular groove, isosceles trapezoidal groove, second rectangular groove, and third rectangular groove of the fourth hollow groove of the transmission unit are symmetrical about the first symmetry plane of the radiation unit. The curvature of the fourth hollow groove of the transmission unit is... The first and second planes of the curved groove are symmetrical about the first symmetry plane of the radiating unit. The rear end face of the third rectangular groove of the fourth hollow groove of the transmission unit is on the same plane as the front end face of the metal partition of the radiating unit. The left end face of the third rectangular groove of the fourth hollow groove of the transmission unit is located to the left of the left end face of the third hollow groove of the radiating unit, and the right end face of the third rectangular groove of the fourth hollow groove of the transmission unit is located to the right of the left end face of the third hollow groove of the radiating unit. When a corresponding transmission unit and a radiating unit radiate to the same plane in the vertical 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-stage transition double-ridge waveguide horn of the radiating unit, connecting the two.

4. A low-profile ultra-wideband antenna array according to claim 3, characterized in that... The power supply network includes a second metal plate, an electromagnetic bandgap structure, a 1 to 32 power distribution network, and a metal coaxial probe. The second metal plate is located below the metal patch, and its upper surface is a certain distance from the lower surface of the metal patch. The second metal plate has a cuboid structure, with its length along the front-to-back direction, its width along the left-to-right direction, and its 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 has a slot matching the contour of the 1 / 32 power distribution network, which extends vertically through the second metal plate. The 1 / 32 power distribution network is formed by placing microstrip lines within the slot. The 1 / 32 power distribution network has one input terminal and 32 output terminals, each corresponding to one of the 32 transmission units. The input terminal of the 1 / 32 power distribution network is connected to the metal coaxial probe. The input terminal of the 1 / 32 power distribution network receives an external radio frequency signal through the metal coaxial probe. The 1 / 32 power distribution network is used to divide the external radio frequency signal received at its input terminal into 32 equal radio frequency signals, which are then coupled and fed into the curved slots of the fourth and fifth hollow slots of the 32 transmission units, symmetrical to the curved slots of the fourth hollow slot. When the curved slot of the fourth hollow slot of a certain transmission unit... When an RF signal is fed into the fifth slot symmetrical to the curved slot of the fourth slot, the RF signal at the curved slot of the fourth slot of the transmission unit is transmitted to the first rectangular slot of the fourth slot of the transmission unit, and then fed into the first waveguide step and the second waveguide step of the first fourth-stage transition double-ridge waveguide horn of the radiation unit corresponding to the transmission unit. The RF signal at the fifth slot symmetrical to the curved slot of the fourth slot of the transmission unit is transmitted to the fifth slot symmetrical to the first rectangular slot of the fourth slot of the transmission unit, and then fed into the second fourth-stage transition double-ridge waveguide horn of the radiation unit corresponding to the transmission unit. The electromagnetic bandgap structure is composed of multiple metal cylinders, the axes of which are all along the vertical direction, and their lower end faces are all fixed and in contact with the upper end face of the second metal plate, and their upper end faces are all fixed and in contact with the lower end face of the metal patch. The multiple metal cylinders are distributed around the gap to prevent electromagnetic leakage.

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