Ultra-wideband circularly polarized wide-beam four-ridged horn antenna

Abstract

The application discloses an ultra-wideband circularly polarized wide-beam four-ridged horn antenna, which comprises four ridges arranged in a circle and a bottom-closed and top-open metal horn side wall, the ridges are connected with the upper surface of the bottom of the metal horn side wall, the lower surface of the bottom of the metal horn side wall is connected with a power division and phase shift network, the power division and phase shift network is connected with metal probes respectively arranged between two adjacent ridges of the four ridges, and the other two ridges are in contact with the cladding part of the metal probes; the working frequency band and the beam width are improved under the premise of small size by loading a stepped radiation structure on the upper part of the metal horn side wall, the beam width is regulated by adjusting the height and width of each layer of the stepped radiation structure, the beam width is further improved by introducing a circular slot on the metal horn side wall, and meanwhile, the metal probes which are bent by 90 degrees are arranged in the probe baffle, the side-feeding form of the four-ridged horn antenna is changed into bottom-feeding, and the occupation of the lateral space can be reduced without changing the original performance of the antenna.

Description

Technical Field

[0001] This invention belongs to the field of horn antenna technology, and specifically relates to an ultra-wideband circularly polarized wide-beam four-ridge horn antenna. Background Technology

[0002] With the escalating nature of information warfare, the requirements for the stealth, anti-jamming capabilities, and reliability of missile-borne communication systems are becoming increasingly stringent. During real-time operation, the missile's flight attitude is constantly changing, resulting in complex motion characteristics, and antenna installation space is limited in missile-borne applications. Simultaneously, the increasing complexity of the electromagnetic environment places stricter demands on antenna polarization characteristics, rendering commonly used linearly polarized antennas increasingly inadequate. Circularly polarized waves, on the other hand, can suppress multipath fading, interconnect with any linearly polarized antenna, and resist interference from the ionosphere and weather phenomena such as rain and fog during propagation.

[0003] Airborne antennas need to combine advantages such as wide bandwidth, circular polarization, low profile, and high gain. On the one hand, the antenna must have a wide beam, ideally covering the upper half of the airspace; on the other hand, the gain in the low elevation angle region must not be too low, meaning the antenna must have uniform radiation characteristics throughout the entire upper airspace. The radiation pattern of such wide-beam antennas is hemispherical in the upper half of the airspace, hence the name hemispherical beam antenna, or simply a hemispherical antenna in engineering. To achieve the highest possible gain at low elevation angles, the radiation gain in the direction of maximum radiation needs to be "suppressed" to compensate for the low elevation angle direction. Therefore, when viewed in a Cartesian coordinate system, the direction of the hemispherical wide-beam antenna... Figure 1 Generally, they are flat-topped. Therefore, studying the structure and mechanism of ultra-wideband low-profile circularly polarized hemispherical radiating antennas is a key technical challenge in the design and testing of missile-borne antennas.

[0004] Patent application CN112615145B discloses a hemispherical ultra-wideband antenna, which includes a radome, a cross-shaped dielectric substrate, a bent cross-shaped dipole, a complementary parasitic dipole, a feed balun, a metal network cover plate, a network dielectric substrate, a power divider phase-shifting network, metallized vias, and a metal base plate. The radome adopts a hollow parabolic structure with local thickening at the bottom. The bent cross-shaped dipole has two consecutive bent arms, and the complementary parasitic dipole has complementary structures on both sides. The antenna can produce a radiation pattern greater than -3 dBi at elevation angles (±70 degrees). However, the impedance bandwidth of this antenna is only 68.2%, and only elevation angle radiation patterns at 0°, 45°, 90°, and 135° are shown; the azimuth radiation pattern is not shown.

[0005] There are three existing circular polarization techniques. The first is the double-arm helical antenna. While the beamwidth and operating bandwidth of the double-arm helical antenna are sufficient, the helix width becomes very narrow when operating at high frequencies. This results in poor power handling performance and makes the extremely narrow helix difficult to manufacture. The second method involves feeding vertically placed linearly polarized elements with equal amplitude and a 90° phase difference. However, this produces periodic dips when using Vivaldi or log-periodic antennas, and the operating bandwidth is limited when using dipole antennas. The third method is the four-ridged horn antenna, which has a relatively narrow beamwidth at high frequencies. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the present invention aims to provide an ultra-wideband circularly polarized wide-beam quad-ridged horn antenna. By loading a stepped radiation structure on the upper part of the metal horn sidewall, the operating bandwidth and beamwidth are improved while maintaining a small size. The beamwidth is controlled by adjusting the height and width of each layer of the stepped radiation structure. A circular slit is introduced on the metal horn sidewall to further improve the beamwidth. At the same time, a 90° bent metal probe is placed inside the probe baffle. This method changes the side-feed form of the quad-ridged horn antenna to a bottom-feed form, which can reduce the lateral space occupation without changing the original performance of the antenna.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] An ultra-wideband circularly polarized wide-beam four-ridge horn antenna includes four ridges 1 arranged in a circular shape and a metal horn sidewall 2 that is closed at the bottom and open at the top. The ridges 1 pass through the metal horn sidewall 2 and are connected to its bottom upper surface. A power divider phase shifter network 3 is connected to the bottom lower surface of the metal horn sidewall 2. Metal probes 6 are connected between the power divider phase shifter network 3 and two adjacent ridges 1. The other two ridges 1 are in contact with the cladding portion of the metal probes 6. A stepped radiation structure 7 is arranged between two adjacent ridges 1 located on the upper part of the metal horn sidewall 2.

[0009] The sides of the ridge 1 are all connected to metal disc structures 4, which are semi-circular metal pillars with straight edges that contact the ridge 1.

[0010] The metal horn sidewall 2 has a through hole 10 on its bottom upper surface, and the ridge 1 is inserted into the metal horn sidewall 2 and connected to the through hole 10 on its bottom upper surface.

[0011] Screw holes 8 are provided at corresponding positions on the metal horn sidewall 2 and the ridge 1. A first screw 5 is provided inside the screw hole 8. The first screw 5 passes through the screw hole 8 on the metal horn sidewall 2 and connects to the middle of the ridge 1.

[0012] The power divider phase shifter network 3 includes a power divider phase shifter network dielectric substrate 15. A metal patch 16 is provided on the upper surface of the power divider phase shifter network dielectric substrate 15, and a metal cladding layer 18 is provided on the lower surface of the power divider phase shifter network dielectric substrate 15. The metal cladding layer 18 is connected to the metal patch 16 through metallized vias.

[0013] The metallized vias include two types: a first type of metallized via 14-1 and a second type of metallized via 14-2. The first type of metallized via 14-1 is located at the tail of the two ports of the metal patch 16, and the second type of metallized via 14-2 is located at the tail of the short-circuit stub of the metal patch 16.

[0014] The metal probe 6 is bent at 90°. One end of the metal probe 6 is connected to the first metallized via 14-1 at the tail of the two ports of the metal patch 16. The other end of the metal probe 6 is inserted into the interior of two adjacent ridges 1 of the four ridges 1 to feed the antenna. The other two ridges 1 are in contact with the cladding portion of the metal probe 6.

[0015] Circular slits 9 are provided on the metal horn sidewall 2 located directly below the stepped radiating structure 7.

[0016] The bottom of the metal horn sidewall 2 is covered with a probe baffle 17, and the metal probe 6 is located inside the probe baffle 17.

[0017] The probe baffle 17 includes a first probe baffle 11 and a second probe baffle 12. The first probe baffle 11 is a quarter-circle ring, and the second probe baffle 12 is a three-quarter-circle ring. The first probe baffle 11 is connected to the second probe baffle 12 by a second screw 13.

[0018] The power divider phase shifter network 3 can be replaced by a bridge for power supply.

[0019] Compared with the prior art, the present invention has the following technical effects:

[0020] 1. The present invention loads a stepped radiation structure 7 on the upper part of the metal horn sidewall 2. On the one hand, the scattering effect of the stepped radiation structure 7 fills the gain depression in the azimuth plane. At the same time, the shape of the stepped radiation structure 7 gradually approaches the center of the antenna axis as the height increases, resulting in better coupling and scattering effect. On the other hand, this stepped radiation structure 7 reduces the overall radiation aperture of the antenna, achieving a wider beamwidth in the elevation plane without changing the antenna size.

[0021] 2. This invention loads metal disc structures 4 at the edges of the four ridges 1. On the one hand, the metal disc structures 4 can extend the current path and improve the low-frequency matching of the antenna. On the other hand, at high frequencies, the metal disc structures 4 can guide the current at the opening of the circular waveguide and form a side gap with the edge of the circular waveguide opening, increasing the radiation intensity at low elevation angles. This significantly improves the low elevation angle gain in the high-frequency band, enabling the antenna to achieve a wider operating bandwidth (operating frequency band of 8-40GHz) than the cross dipole antenna.

[0022] 3. By inserting the ridge 1 into the metal horn sidewall 2 and connecting it with the through hole 10 on its bottom upper surface, and connecting the metal horn sidewall 2 with the middle of the ridge 1, the stability of the antenna can be improved on the one hand, and the full contact between the ridge 1 and the metal horn sidewall 2 can be ensured on the other hand.

[0023] 4. The present invention can feed a four-ridged horn antenna with equal amplitude and 90° phase difference through the power divider phase shifter network 3, so that the antenna can achieve circular polarization; the power divider phase shifter network 3 is connected to two adjacent ridges 1 of the four ridges 1 by using a metal probe 6 bent at 90°. The metal probe 6 is located inside the probe baffle 17. The present invention can reduce the space occupied by the side cable by changing the side feed to the bottom feed.

[0024] 5. By loading a circular slot 9 structure on the metal horn sidewall 2, the azimuth radiation pattern is made more uniform and smooth, achieving a beamwidth in the azimuth plane that is wider than that of a cross dipole antenna.

[0025] Slotting in various waveguides such as rectangular waveguides, coaxial lines, and circular waveguides can create horizontal omnidirectional antennas; the radiation from the circular slot can effectively fill the pattern depressions, thereby improving the antenna's low elevation gain.

[0026] In summary, this invention, by using all-metal materials and loading a stepped radiation structure 7, a circular slit 9, and a metal disc structure 4, achieves an impedance bandwidth of 133.4% and a spatial coverage of ±90° pitch within the operating bandwidth greater than -5 dBi, while also exhibiting superior power handling performance. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of the antenna of the present invention.

[0028] Figure 2 This is an exploded view of part of the antenna structure of the present invention.

[0029] Figure 3 This is a schematic diagram of the connection between the power divider phase shifter network 3 and the spine 1 of the present invention.

[0030] Figure 4 This is a schematic diagram of the structure of the spine 1 of the present invention.

[0031] Figure 5 This is a schematic diagram of the metal disc structure 4 of the present invention.

[0032] Figure 6 This is a schematic diagram of the structure of the metal horn sidewall 2 of the present invention.

[0033] Figure 7 This is a schematic diagram of the connection between the ridge 1 and the metal probe 6 of the present invention.

[0034] Figure 8 This is a schematic diagram of the bottom structure of the metal horn sidewall 2 of the present invention.

[0035] Figure 9(a) is a schematic diagram of the front structure of the power divider phase shifter network 3, and Figure 9(b) is a schematic diagram of the back structure of the power divider phase shifter network 3.

[0036] Figure 10 This is a schematic diagram of the circular slit 9 of the present invention.

[0037] Figure 11 This is a top view of the metal horn sidewall 2 of the present invention.

[0038] Figure 12 This is a diagram showing the VSWR and axial ratio of the four-ridged horn antenna of the present invention.

[0039] Figure 13 This is the pitch diagram of the present invention, wherein, Figure 13 (a) is the radiation pattern at 8 GHz. Figure 13 (b) is the radiation pattern at 18 GHz. Figure 13 (c) is the radiation pattern at 28 GHz. Figure 13 (d) is the radiation pattern at 40 GHz.

[0040] Figure 14 This is the azimuth pattern of the present invention at 8GHz, 18GHz, 28GHz, and 40GHz.

[0041] Among them, 1. Ridge; 2. Metal speaker sidewall; 3. Power divider phase shifter network; 4. Metal disc structure; 5. First screw; 6. Metal probe; 7. Stepped radiation structure; 8. Screw hole; 9. Circular gap; 10. Through hole; 11. First probe baffle; 12. Second probe baffle; 13. Second screw; 14-1. First type of metallized via; 14.2. Second type of metallized via; 15. Power divider phase shifter network dielectric substrate; 16. Metal patch; 17. Probe baffle; 18. Metal coating. Detailed Implementation

[0042] The technical solution adopted by the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0043] Current circularly polarized quad-ridged horn antennas have relatively large horn diameters and long antennas. However, the larger the horn antenna's diameter, the narrower the beamwidth. Therefore, to achieve a wider beamwidth with existing horn antennas, the horn antenna's diameter needs to be reduced. But a smaller diameter also results in a worse VSWR (Standing Wave Ratio). To improve beamwidth, a method must be found to reduce the horn antenna's diameter without affecting the VSWR.

[0044] To address this issue, the present invention proposes a four-ridged horn antenna with a stepped radiation structure 7, which, in comparison, improves the operating bandwidth and beamwidth without affecting the standing wave ratio. Furthermore, slotting the sidewalls of the horn antenna further enhances the beamwidth. Changing the side-feed configuration of the four-ridged horn antenna to a bottom-feed configuration reduces the lateral space occupied and provides excellent radiation performance.

[0045] The present invention proposes an ultra-wideband circularly polarized wide-beam four-ridged horn antenna, which mainly realizes the ultra-wideband and wide-beam performance of circularly polarized antennas. Figure 1 This is an overall structural diagram of the antenna. To extend the impedance bandwidth, this invention sets a suitable ridge curve equation; the ridges are sharpened, the matching cavity is optimized, and a series of structures are loaded to adjust the impedance characteristics at the circular waveguide opening; to extend the axial ratio bandwidth, this invention controls the symmetry of the two pairs of ridges 1, adjusts the size of the matching cavity space, and reasonably adjusts the phase difference between the two polarized waves in the high-frequency band; while ensuring normal hemispherical radiation at low frequencies, the high-frequency beam is broadened. To improve the low elevation gain in the azimuth plane at high frequencies, this invention loads a metal disc structure 4 on the side of ridge 1, using side slot radiation to improve the low elevation gain; a stepped radiation structure 7 is introduced at the circular waveguide opening to eliminate the dip in the low elevation gain in the high-frequency azimuth plane; and circular slots 9 and metal disc structures 4 are introduced in the circular waveguide section to further improve the low elevation gain at high frequencies; ultimately, the antenna achieves good circularly polarized hemispherical radiation performance in the 8-40GHz range. Specifically:

[0046] like Figure 1 , Figure 2 As shown, an ultra-wideband circularly polarized wide-beam four-ridged horn antenna includes four ridges 1 arranged in a circular shape and a metal horn sidewall 2 that is closed at the bottom and open at the top. The ridges 1 penetrate into the metal horn sidewall 2 and are connected to its bottom upper surface. The bottom lower surface of the metal horn sidewall 2 is connected to a power-dividing phase-shifting network 3. Figure 3 As shown, the power divider phase shifter network 3 is connected to two adjacent ridges 1 of the four ridges 1, and the other two ridges 1 are in contact with the cladding portion of the metal probes 6.

[0047] like Figure 4As shown, the ridge 1 includes a radiating section, a waveguide section, and a fixing section. The radiating section is an arc-shaped structure that extends outward along the metal horn sidewall 2. The fixing section is rectangular and is inserted into the metal horn sidewall 2. The remaining part of the ridge 1 is the waveguide section, which is rectangular and directly contacts the metal probe 6 or the cladding of the metal probe 6. Metal disc structures 4 are connected to the sides of the ridge 1. Figure 5 As shown, the metal disc structure 4 is a semi-circular metal column, with the straight edge of the semi-circle in contact with the ridge 1.

[0048] The present invention extends a metal disc structure 4 on the side of the ridge 1. The metal disc structure 4 can extend the current path and improve the low-frequency matching. On the other hand, at high frequencies, the metal disc structure 4 can guide the current at the opening of the circular waveguide and form a side gap with the edge of the opening of the circular waveguide, thereby increasing the radiation intensity at low elevation angles and significantly improving the low elevation angle gain in the high-frequency band.

[0049] like Figure 6 , Figure 7 , Figure 11 As shown, a through hole 10 is provided on the bottom upper surface of the metal horn sidewall 2, and the ridge 1 is inserted into the metal horn sidewall 2 and connected to the through hole 10 provided on its bottom upper surface.

[0050] like Figure 8 As shown, screw holes 8 are provided at corresponding positions in the middle of the metal horn sidewall 2 and the ridge 1. There are four screw holes 8 in total. A first screw 5 is provided inside the screw hole 8. The first screw 5 passes through the screw hole 8 on the metal horn sidewall 2 and connects to the middle of the four ridges 1.

[0051] On the one hand, it can improve the stability of the antenna, and on the other hand, it can ensure that the ridge 1 and the metal horn sidewall 2 are in full contact.

[0052] The present invention introduces a first screw 5 between the metal sidewall 2 and the ridge 1 to facilitate the installation and fixation of the ridge 1. The first screw 5 has a diameter of 1.6 mm, a length of 4 mm, and is made of stainless steel.

[0053] As shown in Figures 9(a) and 9(b), the power divider phase shifter network 3 includes a power divider phase shifter network dielectric substrate 15. A metal patch 16 is provided on the upper surface of the power divider phase shifter network dielectric substrate 15, and a metal cladding layer 18 is provided on the lower surface of the power divider phase shifter network dielectric substrate 15. The metal cladding layer 18 is connected to the metal patch 16 through metallized vias. The metallized vias include two types: a first type of metallized via 14-1 and a second type of metallized via 14-2. The first type of metallized via 14-1 is located at the tail of the two ports of the metal patch 16, and the second type of metallized via 14-2 is located at the tail of the short-circuit stub of the metal patch 16.

[0054] The metal probe 6 is bent at 90°. One end of the metal probe 6 is connected to the first metallized via 14-1 at the tail of the two ports of the metal patch 16. The other end of the metal probe 6 is inserted into the interior of two adjacent ridges 1 of the four ridges 1 to feed the antenna. The other two ridges 1 are in contact with the cladding portion of the metal probe 6.

[0055] The power divider phase shifter network 3 can feed the four-ridged horn antenna with equal amplitude and 90° phase difference, so that the antenna can achieve circular polarization; the present invention changes the side feed to the bottom feed, which can reduce the space occupied by the side cabling.

[0056] For optimizing antenna standing waves, Bezier curves can be used to finely control ridge 1.

[0057] like Figure 10 As shown, a stepped radiation structure 7 is arranged between two adjacent ridges 1 on the upper part of the metal horn sidewall 2. The stepped radiation structure 7 includes five steps, wherein the thickness of each step is consistent, while the width decreases sequentially upwards to ensure that the two sides of each step remain on the same plane.

[0058] On the one hand, the scattering effect of the stepped radiation structure 7 fills the gain depression in the azimuth plane. At the same time, the shape of the stepped radiation structure 7 gradually approaches the center of the antenna axis as the height increases, resulting in better coupling and scattering effects. On the other hand, this stepped radiation structure 7 reduces the overall radiation aperture of the antenna and also widens the beamwidth.

[0059] The stepped radiating structure 7 of this invention is printed using 3D printing technology, with aluminum alloy as the printing material. The antenna dimensions are: 15.5mm × 15.5mm × 15.88mm.

[0060] like Figure 10 As shown, circular slots 9 are formed on the metal horn sidewall 2 located directly below the stepped radiating structure 7. These slots can be used to create a horizontal omnidirectional antenna by slotting various waveguides such as rectangular waveguides, coaxial lines, and circular waveguides. The radiation from the circular slots 9 effectively fills in the pattern recesses, improving the antenna's low elevation gain.

[0061] like Figure 11 As shown, the bottom of the metal horn sidewall 2 is covered with a probe baffle 17, and the metal probe 6 is located inside the probe baffle 17. This method transforms the side-fed configuration of the four-ridged horn antenna into a bottom-fed configuration, reducing the lateral space occupied without altering the antenna's original performance.

[0062] The probe baffle 17 includes a first probe baffle 11 and a second probe baffle 12. The first probe baffle 11 is a quarter-circle ring, and the second probe baffle 12 is a three-quarter-circle ring. The first probe baffle 11 is connected to the second probe baffle 12 by a second screw 13.

[0063] By setting a probe baffle 17 composed of a first probe baffle 11 with a quarter-circle structure and a second probe baffle 12 with a three-quarter-circle structure, the installation of the 90° bent metal probe 6 can be facilitated.

[0064] The present invention loads a stepped radiation structure 7 on the upper part of the metal horn sidewall 2, combines the metal horn sidewall 2 with the circular gap 9, improves the ridge shape and changes the feeding method to bottom feeding, and feeds the antenna through the designed power divider phase shifter network 3 to achieve circular polarization.

[0065] This invention uses an all-metal structure, which gives the antenna better power handling performance than a helical antenna.

[0066] The principle of the stepped radiation structure 7 proposed in this invention is mainly to improve the beamwidth of the antenna by reducing the radiation aperture and secondary radiation. The stepped structure can be replaced with other similar structures to still achieve the purpose of the invention. The Bezier curve of the antenna ridge can be replaced with other more refined curve models. In addition, the power divider phase shifter network 3 designed for the antenna can be replaced with a bridge circuit, which can also achieve the design of circular polarization.

[0067] Figure 12 The standing wave ratio (VSWR) and axial ratio of the four-ridged horn antenna are given. The figure shows that the antenna can achieve a VSWR of less than 2.5 and an axial ratio of less than 3 dB within an operating bandwidth of 8-40 GHz. Figure 13 Figures (a)-(d) show the antenna radiation patterns at 8 GHz, 18 GHz, 28 GHz, and 40 GHz, respectively. The figures show the antenna radiation patterns at four angles, and it can be seen that the antenna's -5 dBi beamwidth is ±90°. Figure 14 The antenna azimuth pattern is shown, indicating that the antenna provides greater than -5 dBi coverage within a 360° range in the 8, 18, 28, and 40 GHz azimuth planes. Ultimately, the antenna can achieve airspace coverage of greater than -5 dBi with an elevation range of ±90°.

[0068] In summary, the antenna of this invention exhibits excellent performance: its impedance bandwidth reaches 133.3%, and its 3dB axial ratio bandwidth also reaches 133.3%. Furthermore, within an elevation range of ±90°, the antenna gain is greater than -5dBi, meeting specific spatial coverage requirements. This means that the antenna can operate stably and efficiently over a wide range of signal transmission and reception angles.

[0069] The application prospects of this invention are:

[0070] This invention can be applied to the design of missile-borne antennas, enabling missile-borne antennas to have better beamwidth within a wider operating bandwidth.

[0071] Traditional circularly polarized hemispherical radiating antennas have narrow bandwidths, and their wide beam angles only cover a few surfaces. In contrast, the four-ridged horn antenna based on the stepped radiating structure 7 of this invention simultaneously possesses the advantage of an ultra-wide bandwidth beam, enabling a wide radiation angle within the hemispherical radiation range. When applied to missile-borne antennas, it can be suitable for high power inputs and complex electromagnetic environments. Due to its smaller antenna size and the reduction in lateral space by changing from side-feed to bottom-feed, it can be used in more compact installation spaces.

[0072] Previous four-ridged horn antennas could achieve ultra-wideband coverage, but their large aperture resulted in a narrow beamwidth. The stepped radiation structure 7 proposed in this invention not only enables secondary radiation but also reduces the antenna's radiating aperture. Furthermore, the combination of the metal horn sidewall 2 with the slot antenna further widens the beamwidth, utilizing the radiation from the slots to fill in the dips in the radiation pattern. In addition, the antenna undergoes a series of design improvements to ensure greater stability after fabrication.

Claims

1. An ultra-wideband circularly polarized wide-beam quad-ridged horn antenna, characterized in that, It includes four ridges (1) arranged in a circular shape and a metal horn sidewall (2) that is closed at the bottom and open at the top. The ridges (1) penetrate into the metal horn sidewall (2) and are connected to its bottom upper surface. A power divider phase shifter network (3) is connected to the bottom lower surface of the metal horn sidewall (2). A metal probe (6) is connected between the power divider phase shifter network (3) and two adjacent ridges (1) of the four ridges (1). The other two ridges (1) are in contact with the cladding portion of the metal probe (6). A stepped radiation structure (7) is arranged between two adjacent ridges (1) located on the upper part of the metal horn sidewall (2). The sides of the ridge (1) are all connected to metal disc structures (4), which are semi-circular metal pillars with straight edges of the semi-circle in contact with the ridge (1). Circular slots (9) are provided on the metal horn sidewall (2) located directly below the stepped radiation structure (7). The radiation from the circular slots (9) can effectively fill the pattern pits and improve the low elevation angle gain of the antenna.

2. The ultra-wideband circularly polarized wide-beam quad-ridge horn antenna according to claim 1, characterized in that, The metal horn sidewall (2) has a through hole (10) on its bottom upper surface, and the ridge (1) is inserted into the metal horn sidewall (2) and connected to the through hole (10) on its bottom upper surface; Screw holes (8) are provided at corresponding positions in the middle of the metal horn sidewall (2) and the ridge (1). A first screw (5) is provided inside the screw hole (8). The first screw (5) passes through the screw hole (8) on the metal horn sidewall (2) and connects to the middle of the ridge (1).

3. The ultra-wideband circularly polarized wide-beam quad-ridge horn antenna according to claim 1, characterized in that, The power divider phase shifter network (3) includes a power divider phase shifter network dielectric substrate (15), a metal patch (16) is provided on the upper surface of the power divider phase shifter network dielectric substrate (15), and a metal cladding (18) is provided on the lower surface of the power divider phase shifter network dielectric substrate (15). The metal cladding (18) is connected to the metal patch (16) through metallized vias.

4. The ultra-wideband circularly polarized wide-beam quad-ridge horn antenna according to claim 3, characterized in that, The metallized vias include two types: a first type of metallized via (14-1) and a second type of metallized via (14-2). The first type of metallized via (14-1) is located at the tail of the two ports of the metal patch (16), and the second type of metallized via (14-2) is located at the tail of the short-circuit stub of the metal patch (16).

5. The ultra-wideband circularly polarized wide-beam quad-ridge horn antenna according to claim 4, characterized in that, The metal probe (6) is bent at 90°. One end of the metal probe (6) is connected to the first metallized via (14-1) at the tail of the two ports of the metal patch (16). The other end of the metal probe (6) is inserted into the interior of two adjacent ridges (1) of the four ridges (1) to feed the antenna. The other two ridges (1) are in contact with the cladding portion of the metal probe (6).

6. The ultra-wideband circularly polarized wide-beam quad-ridge horn antenna according to claim 1, characterized in that, The bottom of the metal horn sidewall (2) is wrapped with a probe baffle (17), and the metal probe (6) is located inside the probe baffle (17).

7. The ultra-wideband circularly polarized wide-beam quad-ridge horn antenna according to claim 6, characterized in that, The probe baffle (17) includes a first probe baffle (11) and a second probe baffle (12). The first probe baffle (11) is a quarter ring and the second probe baffle (12) is a three-quarter ring. The first probe baffle (11) is connected to the second probe baffle (12) by a second screw (13).

8. The ultra-wideband circularly polarized wide-beam quad-ridge horn antenna according to claim 1, characterized in that, The power divider phase shifter network (3) is used to feed the bridge.

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