An ultra-wideband circularly polarized antenna with a side-loaded vertical hollow parasitic copper plate

Abstract

The present invention discloses an ultra-wideband circularly polarized antenna with a side-loaded vertical hollow parasitic copper plate, comprising a cross-dipole unit, four side-vertical parasitic copper plates, a rectangular bottom reflector, four nylon columns, and a feed coaxial cable. The present invention extends the current length and increases the S11 impedance bandwidth by dividing the arms of the cross-dipole into two metal patches of different widths; the stepped metal patch can excite the coupling mode at high frequencies, significantly widening the axial ratio bandwidth; by introducing four side-vertical parasitic copper plates, the coupling effect between the parasitic copper plates and the cross-dipole is utilized to generate additional low-frequency resonance points and axial ratio passbands; by opening X-shaped slots on the side-vertical parasitic copper plates, the current distribution is improved, the coupling is enhanced, and the CP low-frequency radiation characteristics are improved, thereby widening the axial ratio bandwidth to 89.1% (0.97-2.53GHz) and the impedance bandwidth to 95.1% (0.85-2.39GHz).

Description

Technical Field

[0001] The invention relates to a circularly polarized cross-dipole antenna, in particular to an ultra-wideband circularly polarized antenna with a vertically hollowed parasitic copper plate loaded on the side. Background Art

[0002] In today's wireless communication systems, circularly polarized antennas with wide impedance bandwidth and wide axial ratio bandwidth are widely used compared to linearly polarized antennas because they can eliminate polarization mismatch and mitigate multipath effects. These antennas are used in applications such as satellite communications, global positioning systems, and radio frequency identification. In recent years, crossed-dipole antennas have been widely adopted in mobile communications and microwave energy harvesting and transmission due to their excellent circular polarization characteristics.

[0003] However, it is currently difficult for circularly polarized cross-dipole antennas to meet the requirements of axial ratio bandwidth (i.e., AR bandwidth) and impedance bandwidth within a wider frequency band. In order to meet the needs of modern wireless communication systems, various broadband cross-dipole antennas have been proposed one after another. There are three main traditional technologies for increasing bandwidth: one is to use various parasitic units, the second is to use wider planar dipoles, and the third is to use multi-layer microstrip patch structures or additional resonators. In 2019, Professor Shang Feng et al. of Xi'an University of Posts and Telecommunications (Journal of Terahertz Science and Electronic Information Technology, 17(3):430-434, 2019) added coupling patches as parasitic units near the cross-dipole arms, and cut and slotted the coupling patches, achieving an impedance bandwidth of 66.7% and an axial ratio bandwidth of 33.3%. In addition, multi-layer microstrip patch structures or additional resonators can also widen the bandwidth to a certain extent, but this makes the antenna design more complicated and increases the manufacturing cost, which is not conducive to mass production.

[0004] For circularly polarized antennas, it is required to achieve a low axial ratio within a wide frequency band so that the antenna can receive signals well in various situations. Therefore, designing an ultra-wideband circularly polarized antenna is of great significance. Summary of the Invention

[0005] To address the narrow impedance bandwidth and axial ratio bandwidth of circularly polarized cross-dipole antennas, this paper proposes an ultra-wideband circularly polarized antenna with side-loaded vertical hollow parasitic copper plates. This planar dipole, composed of stepped metal patches and quarter-wavelength metal rings, generates high-frequency impedance and an AR passband. The introduction of four side vertical parasitic copper plates significantly broadens the impedance bandwidth and axial ratio bandwidth. Slotting the side vertical parasitic copper plates improves current distribution, enhances coupling, and improves low-frequency CP radiation characteristics.

[0006] The technical solution adopted by the present invention to solve the above technical problems is: an ultra-wideband circularly polarized antenna with a side-loaded vertical hollow parasitic copper plate, comprising a cross-dipole unit, four side vertical parasitic copper plates, a rectangular bottom reflector, four nylon columns and a feeding coaxial cable;

[0007] The cross-dipole unit includes a cross-dipole, two metal rings with a quarter of the ring missing, and a rectangular first dielectric substrate layer. The cross-dipole is composed of two dipoles, each of which contains two dipole arms of the same size and shape, and each dipole arm is composed of a small rectangular metal patch and a large rectangular metal patch. The large rectangular metal patches in the two dipoles are the same in size and shape, and the small rectangular metal patches in the two dipoles are different in length. The dipole with the longer small rectangular metal patch is the first type of dipole, and the dipole with the shorter small rectangular metal patch is the second type of dipole. The first type of dipole includes a first dipole arm and a second dipole. Sub-arms, the second type of dipole includes a third dipole arm and a fourth dipole arm; the first dipole arm and the third dipole arm are etched on the upper surface of the first dielectric substrate layer and connected by a metal ring, and the second dipole arm and the fourth dipole arm are etched on the lower surface of the first dielectric substrate layer and connected by another metal ring; the large rectangular metal patches of the first dipole arm, the second dipole arm, the third dipole arm, and the fourth dipole arm are respectively provided with two slits, the two slits being symmetrically arranged on both sides of the connection between the large rectangular metal patch and the small rectangular metal patch, and each large rectangular metal patch is provided with a cut corner on a pair of opposite corners;

[0008] The bottom reflector is arranged directly below the first dielectric substrate layer, the four nylon columns respectively connect the first dielectric substrate layer with the bottom reflector, and the four nylon columns are respectively fixed at the four corners of the first dielectric substrate layer and the bottom reflector; the four side vertical parasitic copper plates are respectively connected vertically to the four sides of the bottom reflector, the bottom surface of each side vertical parasitic copper plate is flush with the bottom surface of the bottom reflector, and the top surface of each side vertical parasitic copper plate is flush with the bottom surface of the first dielectric substrate layer; the middle part of each side vertical parasitic copper plate is opened X-shaped grooves, each of the X-shaped grooves extending through the thickness direction of each of the side perpendicular parasitic copper plates; the bottom reflector comprises a first metal layer, a second dielectric substrate layer, and a second metal layer stacked in sequence, the first metal layer and the second metal layer being of the same material, size, and shape, and the first dielectric substrate layer and the second dielectric substrate layer being made of the same material; the feed coaxial cable passing through the center of the bottom reflector, the inner conductor of the feed coaxial cable being connected to the first dipole arm, and the outer conductor of the feed coaxial cable being connected to the second dipole arm;

[0009] Looking from top to bottom: in the cross-dipole unit, the two dipoles are placed orthogonally, the first dipole arm, the third dipole arm, and the metal ring located on the upper surface of the first dielectric substrate layer are symmetrical with the second dipole arm, the fourth dipole arm, and the metal ring located on the lower surface of the first dielectric substrate layer about the center point of the first dielectric substrate layer, the wide side of the small rectangular metal patch of the first dipole arm is aligned with the long side of the small rectangular metal patch of the third dipole arm, the inner circle of one end of the metal ring connecting the first dipole arm and the third dipole arm is tangent to the midpoint of the wide side of the small rectangular metal patch of the third dipole arm, and the other end passes counterclockwise around the wide side of the small rectangular metal patch of the first dipole arm and is connected to the small rectangular metal patch of the first dipole arm.

[0010] The ultra-wideband circularly polarized antenna with a side-loaded vertical hollow parasitic copper plate of the present invention creates a 90° phase difference between adjacent dipole arms by designing the size and shape of the metal arms of the cross dipoles, thereby generating circularly polarized radiation. Two slits are respectively opened on each dipole arm and the angles are cut to form current disturbances, thereby improving the axial ratio characteristics of the antenna. Four side vertical parasitic copper plates are introduced between the first dielectric substrate layer and the bottom reflector, and the side vertical parasitic copper plates can be equivalent to parasitic elements. Through the strong coupling effect between the side vertical parasitic copper plates and the cross dipoles, additional low-frequency resonance can be generated, greatly broadening the impedance bandwidth and axial ratio bandwidth. In addition, by opening X-shaped slots in the side-loaded vertical hollow parasitic copper plates, the current distribution can be improved, the coupling can be enhanced, the low-frequency axial ratio characteristics can be optimized, and a certain amount of gain can be increased.

[0011] The ultra-wideband circularly polarized antenna of the present invention can have an impedance bandwidth of 95.1% (0.85-2.39GHz), an axial ratio bandwidth of 89.1% (0.97-2.53GHz), and a passband peak gain of approximately 5.1dBic. Compared with traditional cross-dipole antennas, the ultra-wideband circularly polarized antenna of the present invention has a wider impedance bandwidth and axial ratio bandwidth, and its overall size is relatively small, which makes it more practical. The materials used in the ultra-wideband circularly polarized antenna of the present invention are all conventional materials, which are easy to implement and have low production costs. It can be simply manufactured using existing PCB processing technology.

[0012] Preferably, the first dielectric substrate layer is a square with a side length of 78 mm and a thickness of 0.8 mm; the second dielectric substrate layer is a square with a side length of 82 mm and a thickness of 1.93 mm.

[0013] Preferably, the small rectangular metal patch of the first dipole is 17.4 mm long and 6.8 mm wide, and the large rectangular metal patch is 24.1 mm long and 20 mm wide; the small rectangular metal patch of the second dipole is 7.4 mm long and 6.8 mm wide, and the large rectangular metal patch is 24.1 mm long and 20 mm wide.

[0014] Preferably, the side lengths of the triangular cut-off portion corresponding to each of the cut corners are 2.5 mm and 2 mm respectively, wherein 2.5 mm is the side length along the wide side direction of each large rectangular metal patch, and 2 mm is the side length along the long side direction of each large rectangular metal patch.

[0015] Preferably, the inner radius of each metal ring is 6.7 mm and the ring width is 0.3 mm.

[0016] Preferably, each of the slits is 3.4 mm long and 1.2 mm wide; and the thickness of the large rectangular metal patch, the small rectangular metal patch, the first metal layer and the second metal layer are all 0.035 mm.

[0017] Preferably, each of the side vertical parasitic copper plates has a length of 44 mm, a width of 42 mm, and a thickness of 0.8 mm.

[0018] Preferably, each of the X-shaped grooves coincides with the center of the side vertical parasitic copper plate where it is located, and the two grooves constituting each of the X-shaped grooves are respectively arranged along the two diagonals of each of the side vertical parasitic copper plates. The two grooves constituting each of the X-shaped grooves are identical in size and shape, both of which are 35 mm in length and 2 mm in width. When viewed from any side, the distance between the right edge of the side vertical parasitic copper plate and the right edge of the bottom reflector is 7 mm.

[0019] Preferably, the distance between the bottom reflector and the first dielectric substrate layer is 40 mm.

[0020] Preferably, the material of the first dielectric substrate layer and the second dielectric substrate layer are both F4b, which has a relative dielectric constant of 2.2 and a loss tangent of 0.001.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] (1) The ultra-wideband circularly polarized antenna with a side-loaded vertical hollow parasitic copper plate proposed in the present invention extends the current length and increases the S11 impedance bandwidth by dividing the arms of the cross dipole into two metal patches of different widths; this stepped metal patch can excite the coupling mode at high frequencies and significantly widen the axial ratio bandwidth; in addition, two slits are cut at the junction of the two rectangular metal patches, and the patches are chamfered to form current disturbances, change the current phase, and thus widen the axial ratio bandwidth.

[0023] (2) The ultra-wideband circularly polarized antenna with side-loaded vertical hollow parasitic copper plates proposed in the present invention introduces four side vertical parasitic copper plates on the sides of the cross-dipole unit and the bottom reflector, and utilizes the coupling effect between the parasitic copper plates and the cross-dipole to generate additional low-frequency resonance points and axial ratio passbands; by opening X-shaped slots on the side vertical parasitic copper plates, the current distribution is improved, the coupling is strengthened, and the CP low-frequency radiation characteristics are improved, thereby widening the axial ratio bandwidth to 89.1% (0.97-2.53GHz) and the impedance bandwidth to 95.1% (0.85-2.39GHz).

[0024] (3) The proposed ultra-wideband circularly polarized antenna with a side-loaded vertical hollowed parasitic copper plate is made of conventional materials, is easy to manufacture, has low production costs, and can be fabricated using existing PCB processing techniques. Compared to conventional crossed-dipole antennas, the proposed ultra-wideband circularly polarized antenna has a wider impedance bandwidth and axial ratio bandwidth, and its overall size is relatively small, making it more practical for application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 1 is a model diagram of an ultra-wideband circularly polarized antenna according to an embodiment of the present invention;

[0026] Figure 2 is a top view of an ultra-wideband circularly polarized antenna according to an embodiment;

[0027] Figure 3 is a top view of a cross-dipole unit in an embodiment;

[0028] Figure 4 is a side view of an ultra-wideband circularly polarized antenna according to an embodiment;

[0029] Figure 5 This is a front view of a single side vertical parasitic copper plate in the embodiment;

[0030] Figure 6 A bottom view of the ultra-wideband circularly polarized antenna of an embodiment;

[0031] Figure 7 This is a partial enlarged view of the bottom reflector in the embodiment;

[0032] Figure 8 1 is an impedance bandwidth diagram of an ultra-wideband circularly polarized antenna according to an embodiment;

[0033] Figure 9 1 is an axial ratio bandwidth diagram of the ultra-wideband circularly polarized antenna of an embodiment;

[0034] Figure 10 : is a gain diagram of the ultra-wideband circularly polarized antenna in the +Z axis direction of an embodiment;

[0035] Figure 11 1. The antenna radiation patterns of the ultra-wideband circularly polarized antenna of the embodiment at the frequencies of 1.52 GHz and 2.4 GHz, respectively. DETAILED DESCRIPTION

[0036] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0037] As an embodiment, an ultra-wideband circularly polarized antenna with a side-loaded vertical hollow parasitic copper plate, as shown in the figure, includes a cross dipole unit 7, four side vertical parasitic copper plates 8, a rectangular bottom reflector 9, four nylon columns 10 and a feeding coaxial cable 11.

[0038] The cross-dipole unit 7 includes a cross-dipole, two metal rings 5 with one quarter of the metal ring missing, and a rectangular first dielectric substrate layer 6. The cross-dipole is composed of two types of dipoles, each of which contains two dipole arms of the same size and shape. Each dipole arm is composed of a small rectangular metal patch and a large rectangular metal patch. The large rectangular metal patches in the two dipoles are the same in size and shape, and the small rectangular metal patches in the two dipoles are different in length. The dipole with the longer small rectangular metal patch is the first type of dipole, and the dipole with the shorter small rectangular metal patch is the second type of dipole. The first type of dipole includes a first dipole arm 1 and a second dipole. The first and third dipole arms 1 and 3 are etched on the upper surface of the first dielectric substrate layer 6 and connected by a metal ring 5, and the second and fourth dipole arms 2 and 4 are etched on the lower surface of the first dielectric substrate layer 6 and connected by another metal ring 5. The large rectangular metal patches of the first, second, third, and fourth dipole arms 1, 2, 3, and 4 are each provided with two slits 15. The two slits 15 are symmetrically arranged on both sides of the connection between the large rectangular metal patch and the small rectangular metal patch, and each large rectangular metal patch has a pair of cut corners.

[0039] The bottom reflector 9 is arranged directly below the first dielectric substrate layer 6. Four nylon posts 10 connect the first dielectric substrate layer 6 and the bottom reflector 9 respectively. The four nylon posts 10 are fixed at the four corners of the first dielectric substrate layer 6 and the bottom reflector 9 respectively. Four side vertical parasitic copper plates 8 are vertically connected to the four sides of the bottom reflector 9 respectively. The bottom surface of each side vertical parasitic copper plate 8 is flush with the bottom surface of the bottom reflector 9, and the top surface of each side vertical parasitic copper plate 8 is flush with the bottom surface of the first dielectric substrate layer 6. An X-shaped groove 16 is opened in the middle of each side vertical parasitic copper plate 8. Each X A slot 16 extends through the thickness direction of each side of the parasitic copper plate 8. The bottom reflector 9 includes a first metal layer 12, a second dielectric substrate layer 13, and a second metal layer 14 stacked in sequence. The first metal layer 12 and the second metal layer 14 are made of the same material, size, and shape. The first dielectric substrate layer 6 and the second dielectric substrate layer 13 are made of the same material. The feed coaxial cable 11 passes through the center of the bottom reflector 9. The inner conductor of the feed coaxial cable 11 is connected to the first dipole arm 1, and the outer conductor of the feed coaxial cable 11 is connected to the second dipole arm 2.

[0040] Viewed from top to bottom: In the cross-dipole unit 7, two types of dipoles are placed orthogonally. The first dipole arm 1, third dipole arm 3, and metal ring 5 located on the upper surface of the first dielectric substrate layer 6 are symmetrical with the second dipole arm 2, fourth dipole arm 4, and metal ring 5 located on the lower surface of the first dielectric substrate layer 6 about the center point of the first dielectric substrate layer 6. The wide side of the small rectangular metal patch of the first dipole arm 1 is aligned with the long side of the small rectangular metal patch of the third dipole arm 3. The inner circle of one end of the metal ring 5 connecting the first dipole arm 1 and the third dipole arm 3 is tangent to the midpoint of the wide side of the small rectangular metal patch of the third dipole arm 3, and the other end passes counterclockwise around the wide side of the small rectangular metal patch of the first dipole arm 1 and then connects to the small rectangular metal patch of the first dipole arm 1.

[0041] In this embodiment, the first dielectric substrate layer 6 is square, with a side length W of 78 mm and a thickness h1 of 0.8 mm. The second dielectric substrate layer 13 is square, with a side length W0 of 82 mm and a thickness d1 of 1.93 mm. Both the first and second dielectric substrate layers 6 and 13 are made of F4b, which has a relative dielectric constant of 2.2 and a loss tangent of 0.001. The distance H between the bottom reflector 9 and the first dielectric substrate layer 6 is 40 mm.

[0042] The length L1 of the small rectangular metal patch of the first dipole is 17.4 mm and the width W1 is 6.8 mm, and the length L3 of the large rectangular metal patch is 24.1 mm and the width W2 is 20 mm; the length L2 of the small rectangular metal patch of the second dipole is 7.4 mm and the width W1 is 6.8 mm, and the length L3 of the large rectangular metal patch is 24.1 mm and the width W2 is 20 mm.

[0043] The inner radius r of each metal ring 5 is 6.7 mm, and the ring width W d 0.3mm.

[0044] The length L of each slit is 15 d The large rectangular metal patch, the small rectangular metal patch, the first metal layer 12 and the second metal layer 14 all have a thickness d2 of 0.035 mm.

[0045] The side lengths a1 and b1 of the triangular cut-off part corresponding to each cut corner are 2.5 mm and 2 mm respectively, where 2.5 mm is the side length along the wide side direction of each large rectangular metal patch (i.e., the X-axis direction in the figure), and 2 mm is the side length along the long side direction of each large rectangular metal patch (i.e., the Y-axis direction in the figure).

[0046] Each side vertical parasitic copper plate 8 has a length a of 44 mm, a width b of 42 mm, and a thickness h2 of 0.8 mm.

[0047] Each X-shaped slot 16 coincides with the center of the parasitic copper plate 8 on which it is located. The two slots that make up each X-shaped slot 16 are respectively arranged along the two diagonals of each parasitic copper plate 8 on the side. The two slots that make up each X-shaped slot 16 are identical in size and shape, with a length b2 of 35 mm and a width a2 of 2 mm. When viewed from any side, the distance E between the right edge of the parasitic copper plate 8 on the side and the right edge of the bottom reflector 9 is 7 mm.

[0048] Figure 8 The impedance bandwidth diagram of the ultra-wideband circularly polarized antenna with the vertical hollow parasitic copper plate 8 loaded on the side of the above embodiment is shown in FIG. Figure 8 It can be seen that the -10dB impedance bandwidth is 95.1% (0.85~2.39GHz), and the center frequency of the antenna is 1.62Ghz;

[0049] Figure 9 The axial ratio bandwidth diagram of the ultra-wideband circularly polarized antenna of the above embodiment, the -3dB axial ratio bandwidth ARBW is 89.1%

[0050] (0.97~2.53GHz); Figure 10 : is the gain diagram of the ultra-wideband circularly polarized antenna in the +Z-axis direction of the above embodiment. The antenna presents an RHCP wave with a peak gain of about 5.1 dBic at 1.08 GHz. It can be seen that its passband peak gain is about 5.1 dBic. Figure 11 The antenna radiation patterns of the ultra-wideband circularly polarized antenna of the above-mentioned embodiment at 1.52 GHz and 2.4 GHz, respectively, are shown. The measured results are essentially consistent with the simulation results. Furthermore, the ultra-wideband circularly polarized antenna exhibits a good radiation pattern in the 1-2.3 GHz range. Therefore, this ultra-wideband circularly polarized antenna has great application potential and can be widely used in GNSS and modern wireless satellite communication systems.

Claims

1. An ultra-wideband circularly polarized antenna with a side-loaded vertical hollow parasitic copper plate, characterized in that: It includes a cross dipole unit, four side vertical parasitic copper plates, a rectangular bottom reflector, four nylon columns and a feeding coaxial cable; The cross-dipole unit includes a cross-dipole, two metal rings with a quarter of the ring missing, and a rectangular first dielectric substrate layer. The cross-dipole is composed of two dipoles, each of which contains two dipole arms of the same size and shape, and each dipole arm is composed of a small rectangular metal patch and a large rectangular metal patch. The large rectangular metal patches in the two dipoles are the same in size and shape, and the small rectangular metal patches in the two dipoles are different in length. The dipole with the longer small rectangular metal patch is the first type of dipole, and the dipole with the shorter small rectangular metal patch is the second type of dipole. The first type of dipole includes a first dipole arm and a second dipole. Sub-arms, the second type of dipole includes a third dipole arm and a fourth dipole arm; the first dipole arm and the third dipole arm are etched on the upper surface of the first dielectric substrate layer and connected by a metal ring, and the second dipole arm and the fourth dipole arm are etched on the lower surface of the first dielectric substrate layer and connected by another metal ring; the large rectangular metal patches of the first dipole arm, the second dipole arm, the third dipole arm, and the fourth dipole arm are respectively provided with two slits, the two slits being symmetrically arranged on both sides of the connection between the large rectangular metal patch and the small rectangular metal patch, and each large rectangular metal patch is provided with a cut corner on a pair of opposite corners; The bottom reflector is arranged directly below the first dielectric substrate layer, the four nylon columns respectively connect the first dielectric substrate layer with the bottom reflector, and the four nylon columns are respectively fixed at the four corners of the first dielectric substrate layer and the bottom reflector; the four side vertical parasitic copper plates are respectively connected vertically to the four sides of the bottom reflector, the bottom surface of each side vertical parasitic copper plate is flush with the bottom surface of the bottom reflector, and the top surface of each side vertical parasitic copper plate is flush with the bottom surface of the first dielectric substrate layer; the middle part of each side vertical parasitic copper plate is opened X-shaped grooves, each of the X-shaped grooves extending through the thickness direction of each of the side perpendicular parasitic copper plates; the bottom reflector comprises a first metal layer, a second dielectric substrate layer, and a second metal layer stacked in sequence, the first metal layer and the second metal layer being of the same material, size, and shape, and the first dielectric substrate layer and the second dielectric substrate layer being made of the same material; the feed coaxial cable passing through the center of the bottom reflector, the inner conductor of the feed coaxial cable being connected to the first dipole arm, and the outer conductor of the feed coaxial cable being connected to the second dipole arm; Looking from top to bottom: in the cross-dipole unit, the two dipoles are placed orthogonally, the first dipole arm, the third dipole arm, and the metal ring located on the upper surface of the first dielectric substrate layer are symmetrical with the second dipole arm, the fourth dipole arm, and the metal ring located on the lower surface of the first dielectric substrate layer about the center point of the first dielectric substrate layer, the wide side of the small rectangular metal patch of the first dipole arm is aligned with the long side of the small rectangular metal patch of the third dipole arm, the inner circle of one end of the metal ring connecting the first dipole arm and the third dipole arm is tangent to the midpoint of the wide side of the small rectangular metal patch of the third dipole arm, and the other end passes counterclockwise around the wide side of the small rectangular metal patch of the first dipole arm and is connected to the small rectangular metal patch of the first dipole arm.

2. The ultra-wideband circularly polarized antenna with a side-loaded vertical hollow parasitic copper plate according to claim 1, characterized in that: The first dielectric substrate layer is a square with a side length of 78 mm and a thickness of 0.8 mm; the second dielectric substrate layer is a square with a side length of 82 mm and a thickness of 1.93 mm.

3. The ultra-wideband circularly polarized antenna with a side-loaded vertical hollow parasitic copper plate according to claim 2, characterized in that: The small rectangular metal patch of the first dipole is 17.4 mm long and 6.8 mm wide, and the large rectangular metal patch is 24.1 mm long and 20 mm wide; the small rectangular metal patch of the second dipole is 7.4 mm long and 6.8 mm wide, and the large rectangular metal patch is 24.1 mm long and 20 mm wide.

4. The ultra-wideband circularly polarized antenna with a side-loaded vertical hollow parasitic copper plate according to claim 2, characterized in that: The side lengths of the triangular cutout portion corresponding to each of the cut corners are 2.5 mm and 2 mm respectively, wherein 2.5 mm is the side length along the wide side direction of each large rectangular metal patch, and 2 mm is the side length along the long side direction of each large rectangular metal patch.

5. The ultra-wideband circularly polarized antenna with a side-loaded vertical hollow parasitic copper plate according to claim 2, characterized in that: The inner radius of each metal ring is 6.7 mm and the ring width is 0.3 mm.

6. The ultra-wideband circularly polarized antenna with a side-loaded vertical hollow parasitic copper plate according to claim 2, characterized in that: Each of the slits is 3.4 mm long and 1.2 mm wide; the thickness of the large rectangular metal patch, the small rectangular metal patch, the first metal layer, and the second metal layer are all 0.035 mm.

7. The ultra-wideband circularly polarized antenna with a side-loaded vertical hollow parasitic copper plate according to claim 2, characterized in that: Each of the side vertical parasitic copper plates has a length of 44 mm, a width of 42 mm, and a thickness of 0.8 mm.

8. The ultra-wideband circularly polarized antenna with a side-loaded vertical hollowed parasitic copper plate according to claim 7, characterized in that: Each of the X-shaped grooves coincides with the center of the side vertical parasitic copper plate where it is located, and the two grooves constituting each of the X-shaped grooves are respectively arranged along the two diagonals of each of the side vertical parasitic copper plates. The two grooves constituting each of the X-shaped grooves are identical in size and shape, with a length of 35 mm and a width of 2 mm. When viewed from any side, the distance between the right edge of the side vertical parasitic copper plate and the right edge of the bottom reflector is 7 mm.

9. The ultra-wideband circularly polarized antenna with a side-loaded vertical hollowed parasitic copper plate according to claim 2, characterized in that: The distance between the bottom reflector and the first dielectric substrate layer is 40 mm.

10. An ultra-wideband circularly polarized antenna with a side-loaded vertical hollow parasitic copper plate according to any one of claims 1 to 9, characterized in that: The material of the first dielectric substrate layer and the second dielectric substrate layer are both F4b, with a relative dielectric constant of 2.2 and a loss tangent of 0.001.

Images