A low-profile broadband conical beam antenna

Abstract

The present invention discloses a low-profile broadband conical beam antenna, which includes a cylindrical metal back cavity, a circular copper sheet, four L-shaped copper sheets, a metal single cone, and an SMA coaxial probe. A frustum-shaped cavity is provided on the cylindrical metal back cavity, and the frustum-shaped cavity is coaxial with the cylindrical metal back cavity. The circular copper sheet is arranged in the frustum-shaped cavity, and the metal single cone is located in the frustum-shaped cavity. The metal single cone includes a first frustum, a second frustum, a cylindrical copper sheet, and four identical rectangular copper sheets. The first frustum, the second frustum, and the cylindrical copper sheet are arranged in sequence from bottom to top. The four rectangular copper sheets are evenly spaced around the cylindrical copper sheet in a circle. The four L-shaped copper sheets are located in the frustum-shaped cavity and are evenly spaced around the metal single cone in a circle. The SMA coaxial probe passes through the circular copper sheet and is fixedly connected to the lower bottom surface of the first frustum. The advantages are that while being able to generate a conical beam, it has a wide bandwidth, a low profile, and a high gain.

Description

Technical Field

[0001] The present invention relates to a conical beam antenna, and in particular to a low-profile broadband conical beam antenna. Background Art

[0002] Different from traditional pencil beam antennas, conical beam antennas radiate weakly in the normal direction of the aperture, and the maximum radiation direction is on a conical surface at a certain inclination angle with the normal. Moreover, both its radiation pattern and polarization have circumferential symmetry. Based on the particularity of its radiation pattern, conical beam antennas have been widely used in systems such as ground satellite communication terminals, indoor WLAN micro base stations, and radio fuzes. The carriers of ground satellite communication terminals include various mobile carriers such as people and vehicles, and the movement of the carriers is chaotic. In this case, to ensure that the ground satellite communication terminal is always in good connection with the satellite, the radiation pattern of the antenna on the ground satellite communication terminal should have circumferential omnidirectionality. Ground satellite communication terminals in the Northern and Southern Hemispheres are always obliquely below geostationary satellites. Even when communicating with non-synchronous satellites such as low-earth orbit satellites, since the operating speed of low-earth orbit satellites is very fast, the time when the terminal is directly below the satellite is very short. Considering the above two factors, in order to make the main lobe of the antenna beam on the ground satellite communication terminal align with the satellite as much as possible to maintain communication stability, obviously, conical beam antennas are more suitable than traditional pencil beam antennas.

[0003] In the operating scenario of indoor WLAN micro base stations, the positional relationship between communication terminals and micro base stations is similar to satellite communication. In addition, in missile-borne applications, due to the need for fuse-warhead coordination, conical beams with a certain inclination angle are required. In modern warfare, the speed range of aerial targets varies greatly. Armed helicopters can hover, bombers can fly at supersonic speeds, and the maneuverability of various ground targets is also very high. Solving the efficiency problem of fuse-warhead coordination becomes even more prominent. For high-speed targets, a conical beam with a smaller angle between the pointing direction and the missile axis is required, while for low-speed targets, a conical beam with a larger angle between the pointing direction and the missile axis is needed to simplify the complexity of the signal processing system. Therefore, in order to enable the fuse to take into account various targets with different moving speeds and improve the damage efficiency, a reconfigurable conical beam antenna needs to be installed on the fuse to greatly enhance the battlefield adaptability of the fuse system.

[0004] Low-profile conical beam antennas play an important role in applications such as portable satellite communication devices and wireless local area network access terminal devices. These scenarios require the antenna to have advantages such as light weight, small volume, easy adjustment, easy conformal shaping, less occupied space, low wind resistance, and high efficiency. Although a single-cone antenna structure can also achieve a conical beam, the traditional single-cone antenna structure has good broadband only at a height of half a wavelength, which does not conform to the current trend of miniaturization in wireless communication. When reducing the profile, the bandwidth and gain of the antenna also decrease. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a low-profile broadband conical beam antenna that can generate a conical beam while having a wide bandwidth, a low profile, and a high gain.

[0006] The technical solution adopted by the present invention to solve the above technical problems is as follows: A low-profile broadband conical beam antenna includes a cylindrical metal back cavity, a circular copper sheet, four identical L-shaped copper sheets, a metal single cone, and an SMA coaxial probe. A frustum-shaped cavity is provided on the cylindrical metal back cavity. The frustum-shaped cavity is coaxial with the cylindrical metal back cavity. The lower bottom surface of the frustum-shaped cavity and the lower bottom surface of the cylindrical metal back cavity are in the same plane. The upper bottom surface of the frustum-shaped cavity and the upper bottom surface of the cylindrical metal back cavity are in the same plane. The diameter of the upper bottom surface of the frustum-shaped cavity is greater than the diameter of its lower bottom surface and less than the diameter of the cylindrical metal back cavity. The circular copper sheet is arranged in the frustum-shaped cavity. The diameter of the circular copper sheet is equal to the diameter of the lower bottom surface of the frustum-shaped cavity. The circular copper sheet is coaxial with the cylindrical metal back cavity. The lower bottom surface of the circular copper sheet and the lower bottom surface of the cylindrical metal back cavity are in the same plane. The metal single cone is located in the frustum-shaped cavity. The metal single cone includes a first frustum, a second frustum, a cylindrical copper sheet, and four identical rectangular copper sheets. The first frustum, the second frustum, and the cylindrical copper sheet are arranged in sequence from bottom to top. The first frustum, the second frustum, and the cylindrical copper sheet are all coaxial with the frustum-shaped cavity. The diameter of the upper bottom surface of the first frustum is greater than the diameter of its lower bottom surface and less than the diameter of the circular copper sheet. The lower bottom surface of the first frustum is attached and fixedly connected to the upper end surface of the circular copper sheet. The lower bottom surface of the second frustum is attached and fixedly connected to the upper bottom surface of the first frustum. The diameter of the lower bottom surface of the second frustum is equal to the diameter of the upper bottom surface of the first frustum. The diameter of the upper bottom surface of the second frustum is greater than the diameter of its lower bottom surface. The diameter of the upper bottom surface of the second frustum is less than the diameter of the upper bottom surface of the frustum-shaped cavity. The height of the first frustum is greater than the height of the second frustum. The lower bottom surface of the cylindrical copper sheet is attached and fixedly connected to the upper bottom surface of the second frustum. The diameter of the cylindrical copper sheet is greater than the diameter of the upper bottom surface of the second frustum. The diameter of the cylindrical copper sheet is less than the diameter of the upper bottom surface of the frustum-shaped cavity. The height of the cylindrical copper sheet is less than the height of the second frustum. The upper bottom surface of the cylindrical copper sheet and the upper bottom surface of the frustum-shaped cavity are in the same plane. The four rectangular copper sheets are evenly spaced around the cylindrical copper sheet in a circle. The length of the long side of each rectangular copper sheet is greater than the length of its short side. One long side of each rectangular copper sheet is close to the cylindrical copper sheet, and an arc-shaped groove with a depth less than the length of the short side of the rectangular copper sheet is provided at this long side. The cylindrical copper sheet is embedded in the arc-shaped grooves of the four rectangular copper sheets. The outer side wall of the cylindrical copper sheet is completely attached and fixedly connected to the side walls of the arc-shaped grooves at the four rectangular copper sheets. The upper end surfaces of the four rectangular copper sheets and the upper end surface of the cylindrical copper sheet are in the same plane.The lower end faces of the four rectangular copper sheets are in the same plane as the lower end face of the cylindrical copper sheet, and the sum of the width length of the rectangular copper sheet and the diameter of the cylindrical copper sheet is less than the upper bottom diameter of the frustum-shaped cavity; the four L-shaped copper sheets are located in the frustum-shaped cavity and are evenly spaced along a circle around the metal single cone. Each L-shaped copper sheet includes a first copper sheet and a second copper sheet respectively. The second copper sheet is above the first copper sheet. The length of the first copper sheet is greater than the length of the second copper sheet. The upper bottom surface of the first copper sheet and the lower bottom surface of the second copper sheet are connected and in a fitting state; the lower bottom surface of the first copper sheet in each L-shaped copper sheet is fixedly connected to the upper end face of the circular copper sheet, and the upper bottom surface of the second copper sheet in each L-shaped copper sheet is fixedly connected to the outer side surface of the second frustum of the metal single cone. The angle between the first copper sheet and the circular copper sheet in each L-shaped copper sheet is complementary to the angle between the second copper sheet and the circular copper sheet in this L-shaped copper sheet; the SMA coaxial probe passes through the center of the circular copper sheet and is fixedly connected to the center of the lower bottom surface of the first frustum.,

[0007] The diameter of the cylindrical metal back cavity is 50 mm, the height is 3 mm, the lower bottom diameter of the frustum-shaped cavity is 31 mm, the upper bottom diameter is 39 mm, the height is 3 mm, the diameter of the circular copper sheet is 31 mm, the lower bottom diameter of the first frustum is 2.8 mm, the upper bottom diameter is 7.8 mm, the height is 1.8 mm, the lower bottom diameter of the second frustum is 7.8 mm, the upper bottom diameter is 16.115 mm, the height is 1 mm, the diameter of the cylindrical copper sheet is 20.5 mm, the height is 0.2 mm, the long side length of the rectangular copper sheet is 6 mm, the width side width is 1.2 mm, the radian of the arc-shaped groove is 33.4°, and the depth is 0.448 mm.

[0008] Each L-shaped copper sheet is formed by bending a straight copper sheet with a square cross-section once. The side length of the square is 1.2 mm. The first copper sheet and the second copper sheet are two bent segments of the straight copper sheet. The length of the first copper sheet is 4 mm, and the length of the second copper sheet is 3.6 mm. Among them, the angle between the first copper sheet and the circular copper sheet is 21.8°, and the angle between the second copper sheet and the circular copper sheet is 158.2°.

[0009] Compared with the prior art, the advantages of the present invention are that a low-profile broadband conical beam antenna is constructed by a cylindrical metal back cavity, a circular copper sheet, four identical L-shaped copper sheets, a metal single cone, and an SMA coaxial probe. A frustum-shaped cavity is provided on the cylindrical metal back cavity. The frustum-shaped cavity is coaxial with the cylindrical metal back cavity. The lower bottom surface of the frustum-shaped cavity and the lower bottom surface of the cylindrical metal back cavity are in the same plane. The upper bottom surface of the frustum-shaped cavity and the upper bottom surface of the cylindrical metal back cavity are in the same plane. The diameter of the upper bottom surface of the frustum-shaped cavity is greater than the diameter of its lower bottom surface and less than the diameter of the cylindrical metal back cavity. The circular copper sheet is arranged in the frustum-shaped cavity. The diameter of the circular copper sheet is equal to the diameter of the lower bottom surface of the frustum-shaped cavity. The circular copper sheet is coaxial with the cylindrical metal back cavity. The lower bottom surface of the circular copper sheet and the lower bottom surface of the cylindrical metal back cavity are in the same plane. The metal single cone is located in the frustum-shaped cavity. The metal single cone includes a first frustum, a second frustum, a cylindrical copper sheet, and four identical rectangular copper sheets. The first frustum, the second frustum, and the cylindrical copper sheet are arranged in sequence from bottom to top. The first frustum, the second frustum, and the cylindrical copper sheet are all coaxial with the frustum-shaped cavity. The diameter of the upper bottom surface of the first frustum is greater than the diameter of its lower bottom surface and less than the diameter of the circular copper sheet. The lower bottom surface of the first frustum is attached to and fixedly connected to the upper end surface of the circular copper sheet. The lower bottom surface of the second frustum is attached to and fixedly connected to the upper bottom surface of the first frustum. The diameter of the lower bottom surface of the second frustum is equal to the diameter of the upper bottom surface of the first frustum. The diameter of the upper bottom surface of the second frustum is greater than the diameter of its lower bottom surface. The diameter of the upper bottom surface of the second frustum is less than the diameter of the upper bottom surface of the frustum-shaped cavity. The height of the first frustum is greater than the height of the second frustum. The lower bottom surface of the cylindrical copper sheet is attached to and fixedly connected to the upper bottom surface of the second frustum. The diameter of the cylindrical copper sheet is greater than the diameter of the upper bottom surface of the second frustum. The diameter of the cylindrical copper sheet is less than the diameter of the upper bottom surface of the frustum-shaped cavity. The height of the cylindrical copper sheet is less than the height of the second frustum. The upper bottom surface of the cylindrical copper sheet and the upper bottom surface of the frustum-shaped cavity are in the same plane. The four rectangular copper sheets are evenly spaced around the cylindrical copper sheet in a circle. The length of the long side of each rectangular copper sheet is greater than the length of its short side. One long side of each rectangular copper sheet is close to the cylindrical copper sheet, and an arc-shaped groove with a depth less than the length of the short side of the rectangular copper sheet is provided at this long side. The cylindrical copper sheet is embedded in the arc-shaped grooves of the four rectangular copper sheets. The outer side wall of the cylindrical copper sheet is completely attached to and fixedly connected to the side walls of the arc-shaped grooves at the four rectangular copper sheets. The upper end surfaces of the four rectangular copper sheets and the upper end surface of the cylindrical copper sheet are in the same plane. The lower end surfaces of the four rectangular copper sheets and the lower end surface of the cylindrical copper sheet are in the same plane. The sum of the length of the short side of the rectangular copper sheet and the diameter of the cylindrical copper sheet is less than the diameter of the upper bottom surface of the frustum-shaped cavity;Four L-shaped copper sheets are located inside the frustum-shaped cavity and are evenly spaced around the metal single cone in a circle. Each L-shaped copper sheet includes a first copper sheet and a second copper sheet. The second copper sheet is above the first copper sheet. The length of the first copper sheet is greater than that of the second copper sheet. The upper bottom surface of the first copper sheet is connected to the lower bottom surface of the second copper sheet and they are in a fitting state. The lower bottom surface of the first copper sheet in each L-shaped copper sheet is fixedly connected to the upper end surface of the circular copper sheet. The upper bottom surface of the second copper sheet in each L-shaped copper sheet is fixedly connected to the outer side surface of the second frustum of the metal single cone. The angle between the first copper sheet and the circular copper sheet in each L-shaped copper sheet is complementary to the angle between the second copper sheet and the circular copper sheet in the same L-shaped copper sheet. The SMA coaxial probe passes through the center of the circular copper sheet and is fixedly connected to the center of the lower bottom surface of the first frustum. The first frustum, the second frustum and the cylindrical copper sheet form a tapered metal single cone. The gradual change in the diameter of the metal single cone can effectively achieve a smooth transition from the impedance of the metal single cone to free space, reducing unnecessary reflections and radiation. The design of the four rectangular copper sheets embedded on the outer side surface of the cylindrical copper sheet can shift the impedance bandwidth of the antenna to a lower frequency. The rectangular copper sheets play a guiding role in the surface current of the metal single cone, increasing the path length of the current flowing on the surface of the metal single cone, changing the resonant frequency of the antenna, and effectively changing the low-frequency characteristics of the antenna. The four L-shaped copper sheets connected between the metal single cone and the circular copper sheet are rotationally symmetrically distributed about the center of the metal single cone. The experimental results show that the L-shaped copper sheets can short-circuit the metal single cone, equivalent to introducing inductance, so the standing wave characteristics at the low-frequency end of the antenna can be improved. The L-shaped copper sheets can adjust the current distribution on the surfaces of the metal single cone and the circular copper sheet, achieving the design goal of broadband miniaturization. The structure of the L-shaped copper sheets evenly and symmetrically distributed around the center of the metal single cone ensures that the horizontal omnidirectional radiation performance of the antenna does not change significantly. The cylindrical metal back cavity is equivalent to a sleeve structure, used to broaden the impedance bandwidth. The design of the cylindrical metal back cavity increases the radiation aperture of the antenna and improves the radiation gain of the antenna. The frustum-shaped cavity is mainly used to adjust the impedance bandwidth of the antenna at medium and high frequencies. According to the actual processing and welding principle, the SMA coaxial probe passes through the center of the circular copper sheet and is welded to the center of the lower bottom of the first frustum in the metal single cone. Through the design of each component of the antenna, finally the antenna reaches the broadband performance index and maintains good omnidirectional performance in the entire frequency band range. The experimental simulation results confirm that when the return loss value of the antenna is less than -10 dB, the bandwidth of the antenna achieves a broadband range of 6.05 GHz - 19.82 GHz, and the gain is improved, which is beneficial to long-distance signal transmission. While being able to generate a conical beam, it has a wide bandwidth, a low profile and a high gain. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a three-dimensional view of the low-profile broadband conical beam antenna of the present invention Figure 1 ;

[0011] Figure 2 is the three-dimensional view of the low-profile broadband conical beam antenna of the present invention Figure 2 ;

[0012] Figure 3 is the sectional view of the low-profile broadband conical beam antenna of the present invention;

[0013] Figure 4 is the exploded view of the low-profile broadband conical beam antenna of the present invention;

[0014] Figure 5(a) is the three-dimensional view of the metal single cone and L-shaped copper skin of the low-profile broadband conical beam antenna of the present invention Figure 1 ;

[0015] Figure 5(b) is the three-dimensional view of the metal single cone and L-shaped copper skin of the low-profile broadband conical beam antenna of the present invention Figure 2 ;

[0016] Figure 6 is the three-dimensional view of the cylindrical metal back cavity and SMA coaxial probe of the low-profile broadband conical beam antenna of the present invention;

[0017] Figure 7 is the three-dimensional view of the L-shaped copper skin of the low-profile broadband conical beam antenna of the present invention;

[0018] Figure 8 is the simulated S11 diagram of the low-profile broadband conical beam antenna of the present invention;

[0019] Figure 9 is the E-plane pattern and H-plane pattern of the low-profile broadband conical beam antenna of the present invention at 6G frequency points;

[0020] Figure 10 is the E-plane pattern and H-plane pattern of the low-profile broadband conical beam antenna of the present invention at 9G frequency points;

[0021] Figure 11 is the E-plane pattern and H-plane pattern of the low-profile broadband conical beam antenna of the present invention at 12G frequency points;

[0022] Figure 12 is the E-plane pattern and H-plane pattern of the low-profile broadband conical beam antenna of the invention at 15G frequency points;

[0023] Figure 13 is the E-plane pattern and H-plane pattern of the low-profile broadband conical beam antenna of the invention at 18G frequency points. Detailed implementation manners

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

[0025] Embodiment: AsFigures 1 to 7As shown in the figure, a low-profile broadband conical beam antenna includes a cylindrical metal back cavity 1, a circular copper sheet 2, four identical L-shaped copper sheets 3, a metal single cone, and an SMA coaxial probe 4. A frustum-shaped cavity 5 is provided on the cylindrical metal back cavity 1. The frustum-shaped cavity 5 is coaxial with the cylindrical metal back cavity 1. The lower bottom surface of the frustum-shaped cavity 5 and the lower bottom surface of the cylindrical metal back cavity 1 are in the same plane. The upper bottom surface of the frustum-shaped cavity 5 and the upper bottom surface of the cylindrical metal back cavity 1 are in the same plane. The diameter of the upper bottom surface of the frustum-shaped cavity 5 is greater than the diameter of its lower bottom surface and less than the diameter of the cylindrical metal back cavity 1. The circular copper sheet 2 is arranged in the frustum-shaped cavity 5. The diameter of the circular copper sheet 2 is equal to the diameter of the lower bottom surface of the frustum-shaped cavity 5. The circular copper sheet 2 is coaxial with the cylindrical metal back cavity 1. The lower bottom surface of the circular copper sheet 2 and the lower bottom surface of the cylindrical metal back cavity 1 are in the same plane. The metal single cone is located in the frustum-shaped cavity 5. The metal single cone includes a first frustum 6, a second frustum 7, a cylindrical copper sheet 8, and four identical rectangular copper sheets 9. The first frustum 6, the second frustum 7, and the cylindrical copper sheet 8 are arranged in sequence from bottom to top. The first frustum 6, the second frustum 7, and the cylindrical copper sheet 8 are all coaxial with the frustum-shaped cavity 5. The diameter of the upper bottom surface of the first frustum 6 is greater than the diameter of its lower bottom surface and less than the diameter of the circular copper sheet 2. The lower bottom surface of the first frustum 6 is attached to and fixedly connected to the upper end surface of the circular copper sheet 2. The lower bottom surface of the second frustum 7 is attached to and fixedly connected to the upper bottom surface of the first frustum 6. The diameter of the lower bottom surface of the second frustum 7 is equal to the diameter of the upper bottom surface of the first frustum 6. The diameter of the upper bottom surface of the second frustum 7 is greater than the diameter of its lower bottom surface. The diameter of the upper bottom surface of the second frustum 7 is less than the diameter of the upper bottom surface of the frustum-shaped cavity 5. The height of the first frustum 6 is greater than the height of the second frustum 7. The lower bottom surface of the cylindrical copper sheet 8 is attached to and fixedly connected to the upper bottom surface of the second frustum 7. The diameter of the cylindrical copper sheet 8 is greater than the diameter of the upper bottom surface of the second frustum 7. The diameter of the cylindrical copper sheet 8 is less than the diameter of the upper bottom surface of the frustum-shaped cavity 5. The height of the cylindrical copper sheet 8 is less than the height of the second frustum 7. The upper bottom surface of the cylindrical copper sheet 8 and the upper bottom surface of the frustum-shaped cavity 5 are in the same plane. The four rectangular copper sheets 9 are evenly spaced around the cylindrical copper sheet 8 in a circle. The length of the long side of each rectangular copper sheet 9 is greater than the length of its short side. One long side of each rectangular copper sheet 9 is close to the cylindrical copper sheet 8, and an arc-shaped groove with a depth less than the length of the short side of the rectangular copper sheet 9 is provided at this long side. The cylindrical copper sheet 8 is embedded in the arc-shaped grooves of the four rectangular copper sheets 9. The outer side wall of the cylindrical copper sheet 8 is completely attached to and fixedly connected to the side walls of the arc-shaped grooves at the four rectangular copper sheets 9. The upper end surfaces of the four rectangular copper sheets 9 and the upper end surface of the cylindrical copper sheet 8 are in the same plane. The lower end surfaces of the four rectangular copper sheets 9 and the lower end surface of the cylindrical copper sheet 8 are in the same plane. The sum of the length of the short side of the rectangular copper sheet 9 and the diameter of the cylindrical copper sheet 8 is less than the diameter of the upper bottom surface of the frustum-shaped cavity 5;Four L-shaped copper sheets 3 are located inside the frustum-shaped cavity 5 and are evenly spaced along a circle around the metal single cone. Each L-shaped copper sheet 3 includes a first copper sheet 31 and a second copper sheet 32 respectively. The second copper sheet 32 is above the first copper sheet 31. The length of the first copper sheet 31 is greater than that of the second copper sheet 32. The upper bottom surface of the first copper sheet 31 and the lower bottom surface of the second copper sheet 32 are connected and in a fitting state. The lower bottom surface of the first copper sheet 31 in each L-shaped copper sheet 3 is fixedly connected to the upper end surface of the circular copper sheet 2. The upper bottom surface of the second copper sheet 32 in each L-shaped copper sheet 3 is fixedly connected to the outer side surface of the second frustum 7 of the metal single cone. The angle between the first copper sheet 31 and the circular copper sheet 2 in each L-shaped copper sheet 3 is complementary to the angle between the second copper sheet 32 and the circular copper sheet 2 in the same L-shaped copper sheet 3. The SMA coaxial probe 4 passes through the center of the circular copper sheet 2 and is fixedly connected to the center of the lower bottom surface of the first frustum 6.;

[0026] In this embodiment, the diameter of the cylindrical metal back cavity 1 is 50 mm, the height is 3 mm, the diameter of the lower bottom surface of the frustum-shaped cavity 5 is 31 mm, the diameter of the upper bottom surface is 39 mm, the height is 3 mm, the diameter of the circular copper sheet 2 is 31 mm, the diameter of the lower bottom surface of the first frustum 6 is 2.8 mm, the diameter of the upper bottom surface is 7.8 mm, the height is 1.8 mm, the diameter of the lower bottom surface of the second frustum 7 is 7.8 mm, the diameter of the upper bottom surface is 16.115 mm, the height is 1 mm, the diameter of the cylindrical copper sheet 8 is 20.5 mm, the height is 0.2 mm, the length of the long side of the rectangular copper sheet 9 is 6 mm, the width of the short side is 1.2 mm, the radian of the arc-shaped groove is 33.4°, and the depth is 0.448 mm.

[0027] In this embodiment, each L-shaped copper sheet 3 is formed by bending a straight copper sheet with a square cross-section once. The side length of the square is 1.2 mm. The first copper sheet 31 and the second copper sheet 32 are two bent segments of the straight copper sheet. The length of the first copper sheet 31 is 4 mm, and the length of the second copper sheet 32 is 3.6 mm. Among them, the angle between the first copper sheet 31 and the circular copper sheet 2 is 21.8°, and the angle between the second copper sheet 32 and the circular copper sheet 2 is 158.2°.

[0028] To verify the excellent performance of the low-profile broadband conical beam antenna of the present invention, the low-profile broadband conical beam antenna of the present invention is simulated. Among them, the simulation S11 diagram of the low-profile broadband conical beam antenna of the present invention is as Figure 8 shown. The E-plane pattern and H-plane pattern of the low-profile broadband conical beam antenna of the present invention at the 6G frequency point are as Figure 9 shown. The E-plane pattern and H-plane pattern of the low-profile broadband conical beam antenna of the present invention at the 9G frequency point are as Figure 10 shown. The E-plane pattern and H-plane pattern of the low-profile broadband conical beam antenna of the present invention at the 12G frequency point are as Figure 11As shown, the E-plane pattern and H-plane pattern of the low-profile broadband conical beam antenna of the invention at the 15G frequency point are as follows Figure 12 As shown, the E-plane pattern and H-plane pattern of the low-profile broadband conical beam antenna of the invention at the 18G frequency point are as follows Figure 13 shown.

[0029] Analysis Figure 8 It can be seen that the low-profile broadband conical beam antenna of the present invention has an impedance bandwidth of 6.05 GHz - 19.82 GHz. Analysis Figure 9 It can be seen that the radiation gain of the low-profile broadband conical beam antenna of the present invention is 2.8 dBi at a frequency of 6 GHz and Theta of 28°. From Figure 9 it can be seen that the low-profile broadband conical beam antenna of the present invention has a good conical beam at 6 GHz. Analysis Figure 10 It can be seen that the radiation gain of the low-profile broadband conical beam antenna of the present invention is 6.34 dBi at a frequency of 9 GHz and Theta of 28°. From Figure 10 it can be seen that the low-profile broadband conical beam antenna of the present invention has a good conical beam at 9 GHz. Analysis Figure 11 It can be seen that the radiation gain of the low-profile broadband conical beam antenna of the present invention is 7.8 dBi at the center frequency of 12 GHz and Theta of 28°. From,11 it can be seen that the low-profile broadband conical beam antenna of the present invention has a good conical beam at 12 GHz. Analysis Figure 12 It can be seen that the radiation gain of the low-profile broadband conical beam antenna of the present invention is 8.7 dBi at a frequency of 15 GHz and Theta of 28°. From Figure 12 it can be seen that the low-profile broadband conical beam antenna of the present invention has a good conical beam at 15 GHz. Analysis Figure 13 It can be seen that the radiation gain of the low-profile broadband conical beam antenna of the present invention is 6.7 dBi at a frequency of 18 GHz and Theta of 28°. From Figure 13 it can be seen that the low-profile broadband conical beam antenna of the present invention has a good conical beam at 18 GHz. The above analysis shows that the low-profile broadband conical beam antenna of the present invention has a good conical beam in the whole frequency band, has a wide bandwidth, a low profile and a high gain, and has excellent performance.

Claims

1. A low-profile broadband conical beam antenna, characterized in that It includes a cylindrical metal back cavity, a circular copper sheet, four identical L-shaped copper sheets, a metal single cone, and an SMA coaxial probe. A frustum-shaped cavity is provided on the cylindrical metal back cavity. The frustum-shaped cavity is coaxial with the cylindrical metal back cavity. The lower bottom surface of the frustum-shaped cavity and the lower bottom surface of the cylindrical metal back cavity are in the same plane. The upper bottom surface of the frustum-shaped cavity and the upper bottom surface of the cylindrical metal back cavity are in the same plane. The diameter of the upper bottom surface of the frustum-shaped cavity is greater than the diameter of its lower bottom surface and less than the diameter of the cylindrical metal back cavity. The circular copper sheet is arranged in the frustum-shaped cavity. The diameter of the circular copper sheet is equal to the diameter of the lower bottom surface of the frustum-shaped cavity. The circular copper sheet is coaxial with the cylindrical metal back cavity. The lower bottom surface of the circular copper sheet and the lower bottom surface of the cylindrical metal back cavity are in the same plane. The metal single cone is located in the frustum-shaped cavity. The metal single cone includes a first frustum, a second frustum, a cylindrical copper sheet, and four identical rectangular copper sheets. The first frustum, the second frustum, and the cylindrical copper sheet are arranged in sequence from bottom to top. The first frustum, the second frustum, and the cylindrical copper sheet are all coaxial with the frustum-shaped cavity. The diameter of the upper bottom surface of the first frustum is greater than the diameter of its lower bottom surface and less than the diameter of the circular copper sheet. The lower bottom surface of the first frustum is attached and fixedly connected to the upper end surface of the circular copper sheet. The lower bottom surface of the second frustum is attached and fixedly connected to the upper bottom surface of the first frustum. The diameter of the lower bottom surface of the second frustum is equal to the diameter of the upper bottom surface of the first frustum. The diameter of the upper bottom surface of the second frustum is greater than the diameter of its lower bottom surface. The diameter of the upper bottom surface of the second frustum is less than the diameter of the upper bottom surface of the frustum-shaped cavity. The height of the first frustum is greater than the height of the second frustum. The lower bottom surface of the cylindrical copper sheet is attached and fixedly connected to the upper bottom surface of the second frustum. The diameter of the cylindrical copper sheet is greater than the diameter of the upper bottom surface of the second frustum. The diameter of the cylindrical copper sheet is less than the diameter of the upper bottom surface of the frustum-shaped cavity. The height of the cylindrical copper sheet is less than the height of the second frustum. The upper bottom surface of the cylindrical copper sheet and the upper bottom surface of the frustum-shaped cavity are in the same plane. The four rectangular copper sheets are evenly spaced around the cylindrical copper sheet in a circle. The length of the long side of each rectangular copper sheet is greater than the length of its short side. One long side of each rectangular copper sheet is close to the cylindrical copper sheet, and an arc-shaped groove with a depth less than the length of the short side of the rectangular copper sheet is provided at this long side. The cylindrical copper sheet is embedded in the arc-shaped grooves of the four rectangular copper sheets. The outer side wall of the cylindrical copper sheet is completely attached and fixedly connected to the side walls of the arc-shaped grooves at the four rectangular copper sheets. The upper end surfaces of the four rectangular copper sheets and the upper end surface of the cylindrical copper sheet are in the same plane. The lower end surfaces of the four rectangular copper sheets and the lower end surface of the cylindrical copper sheet are in the same plane.The sum of the width of the rectangular copper sheet and the diameter of the cylindrical copper sheet is less than the upper base diameter of the frustum-shaped cavity; the four L-shaped copper sheets are located inside the frustum-shaped cavity and are evenly spaced around the metal single cone in a circle. Each of the L-shaped copper sheets includes a first copper sheet and a second copper sheet. The second copper sheet is above the first copper sheet. The length of the first copper sheet is greater than the length of the second copper sheet. The upper bottom surface of the first copper sheet and the lower bottom surface of the second copper sheet are connected and in a fitting state; the lower bottom surface of the first copper sheet in each L-shaped copper sheet is fixedly connected to the upper end surface of the circular copper sheet, and the upper bottom surface of the second copper sheet in each L-shaped copper sheet is fixedly connected to the outer side surface of the second frustum of the metal single cone. The angle between the first copper sheet and the circular copper sheet in each L-shaped copper sheet is complementary to the angle between the second copper sheet and the circular copper sheet in the same L-shaped copper sheet; the SMA coaxial probe passes through the center of the circular copper sheet and is fixedly connected to the center of the lower bottom surface of the first frustum.

2. The low-profile broadband conical beam antenna according to claim 1, wherein The diameter of the cylindrical metal back cavity is 50 mm, and its height is 3 mm. The diameter of the lower bottom surface of the frustum-shaped cavity is 31 mm, the diameter of the upper bottom surface is 39 mm, and its height is 3 mm. The diameter of the circular copper sheet is 31 mm. The diameter of the lower bottom surface of the first frustum is 2.8 mm, the diameter of the upper bottom surface is 7.8 mm, and its height is 1.8 mm. The diameter of the lower bottom surface of the second frustum is 7.8 mm, the diameter of the upper bottom surface is 16.115 mm, and its height is 1 mm. The diameter of the cylindrical copper sheet is 20.5 mm, and its height is 0.2 mm. The length of the long side of the rectangular copper sheet is 6 mm, the width of the short side is 1.2 mm, the radian of the arc-shaped groove is 33.4°, and the depth is 0.448 mm.

3. The low-profile broadband conical beam antenna according to claim 1, wherein Each of the L-shaped copper sheets is formed by bending a straight copper sheet with a square cross-section once. The side length of the square is 1.2 mm. The first copper sheet and the second copper sheet are two bent segments of the straight copper sheet. The length of the first copper sheet is 4 mm, and the length of the second copper sheet is 3.6 mm. The included angle between the first copper sheet and the circular copper sheet is 21.8°, and the included angle between the second copper sheet and the circular copper sheet is 158.2°.

Images