Circularly polarized antenna, antenna apparatus, and vehicle

Abstract

The present application relates to the technical field of antennas, provides a circularly polarized antenna, an antenna apparatus, and a vehicle, and can solve the problem in the related art of an excessively large size of circularly polarized antennas. The circularly polarized antenna comprises a ground plane, a dielectric plate, a plurality of first radiation arms, a plurality of parasitic radiation arms, and a feed unit; the dielectric plate is spaced apart from the ground plane; the plurality of first radiation arms are provided on the dielectric plate and constitute at least one crossed dipole; the plurality of parasitic radiation arms are distributed at the edge of the dielectric plate in the circumferential direction of the dielectric plate, each parasitic radiation arm is coupled to a first radiation arm that is close to the parasitic radiation arm, each parasitic radiation arm has a ground end and an open end, the ground end is connected to the ground plane, the open end is located at the edge of the dielectric plate, and the cross-sectional area of the parasitic radiation arm at the ground end is smaller than the cross-sectional area of the parasitic radiation arm at the open end; and the feed unit is used for feeding the first radiation arms. The present application can be used in a vehicle.

Description

Circularly polarized antennas, antenna devices and vehicles

[0001] This application claims priority to Chinese patent application filed on January 20, 2025, with application number 202520134574.1 and entitled "Circularly Polarized Antenna, Antenna Device and Vehicle", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of antenna technology, and in particular to a circularly polarized antenna, antenna device, and vehicle. Background Technology

[0003] With the continuous development of modern wireless communication technology, circularly polarized antennas have been widely used in many fields such as satellite communication, satellite navigation systems, radio frequency identification, and wireless local area networks due to their unique performance advantages, such as reducing multipath interference, counteracting the Faraday rotation effect caused by the ionosphere, and reducing mismatch loss.

[0004] Today, the requirements for communication in the field of vehicle communication are increasing. Vehicles need to have satellite communication capabilities to support satellite communication with multiple networks. In the vehicle environment, to meet the needs of multi-network satellite communication, a wide-bandwidth beam-coordinated circularly polarized antenna is required to effectively receive and transmit signals in different frequency bands, ensuring a stable communication connection with satellites while the vehicle is in motion.

[0005] However, while circularly polarized antennas in related technologies offer the advantage of wide-bandwidth beams, their large size makes them unsuitable for the miniaturization trend in automotive antennas. Within the limited space of a vehicle, large antennas are not only inconvenient to install but may also negatively impact the vehicle's aesthetics and performance. Therefore, there is an urgent need to develop a miniaturized circularly polarized antenna to meet the requirements of multi-network satellite communication in vehicles. Summary of the Invention

[0006] Embodiments of this application provide a circularly polarized antenna, an antenna device, and a vehicle to address the problem of excessively large dimensions of circularly polarized antennas in related technologies.

[0007] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0008] In a first aspect, embodiments of this application provide a circularly polarized antenna, including a ground plane, a dielectric substrate, a plurality of first radiating arms, a plurality of parasitic radiating arms, and a feeding unit; the dielectric substrate and the ground plane are spaced apart along the thickness direction of the dielectric substrate; the plurality of first radiating arms are disposed on the dielectric substrate and form at least one cross dipole, the first end of each first radiating arm is disposed near the central region of the dielectric substrate, and the second end of each first radiating arm is disposed near the edge of the dielectric substrate; the plurality of parasitic radiating arms are distributed along the circumference of the dielectric substrate at the edge of the dielectric substrate, each parasitic radiating arm is coupled to the adjacent first radiating arm, each parasitic radiating arm has a ground end and an open end, the ground end is connected to the ground plane, the open end is located at the edge of the dielectric substrate, and the cross-sectional area of ​​the parasitic radiating arm at the ground end is smaller than the cross-sectional area at the open end; the feeding unit is used to feed power to each first radiating arm.

[0009] In this embodiment of the circularly polarized antenna, the cross-sectional area of ​​the parasitic radiating arm at the ground end is set to be smaller than that at the open end. This is equivalent to making the cross-sectional area of ​​the parasitic radiating arm at the ground end smaller. According to the current distribution law on the parasitic radiating arm when the circularly polarized antenna is working, that is, the ground end is the point of maximum current and the open end is the point of minimum current, reducing the cross-sectional area of ​​the parasitic radiating arm at the point of maximum current can increase the inductance of the parasitic radiating arm. Since the resonant frequency of the antenna is inversely proportional to the inductance of the radiator, increasing the inductance of the parasitic radiating arm can reduce the resonant frequency of the circularly polarized antenna, which is equivalent to increasing the electrical length of the radiator (here, the radiator refers to the first radiating arm and the parasitic radiating arm) in the circularly polarized antenna. Therefore, the physical length of the radiator does not need to be designed to be so large, which helps to reduce the volume of the circularly polarized antenna to meet the installation requirements of vehicle-mounted antennas.

[0010] In some embodiments of the first aspect, the parasitic radiating arm includes a first arm segment and a second arm segment, the second arm segment being connected between the first arm segment and the ground. The cross-sectional area of ​​the second arm segment is smaller than that of the first arm segment, the open end is located in the first arm segment, and the grounded end is located in the second arm segment. This configuration, while ensuring the coupling efficiency between the parasitic radiating arm and the corresponding first radiating arm, also helps to reduce the size of the circularly polarized antenna.

[0011] In some embodiments of the first aspect, both the first and second arm segments are rectangular sheet structures, the length of the short side of the second arm segment is less than the length of the long side of the first arm segment, and the short side of the second arm segment is connected to the middle of the long side of the first arm segment. This configuration can optimize the axial ratio of the circularly polarized antenna.

[0012] In some embodiments of the first aspect, the dielectric substrate is a polygonal plate with multiple corners, and each parasitic radiating arm is located at a corresponding corner, forming a radiating arm group with a nearby first radiating arm. In the radiating arm group, the dimensions of the parasitic radiating arms overlap with those of the first radiating arms in both the length and width directions. This arrangement helps to reduce the size of the circularly polarized antenna.

[0013] In some embodiments of the first aspect, the dielectric substrate is a polygonal plate with multiple edges, and each parasitic radiating arm is located at a corresponding edge, forming a radiating arm group with a nearby first radiating arm; in the radiating arm group, in the length direction of the first radiating arm, the size of the parasitic radiating arm is smaller than the size of the first radiating arm, and the size of the parasitic radiating arm completely overlaps with that of the first radiating arm. This arrangement helps to reduce the volume of the circularly polarized antenna.

[0014] In some embodiments of the first aspect, a notch is provided at the first end of each first radiating arm. This arrangement optimizes the axial ratio of the circularly polarized antenna.

[0015] In some embodiments of the first aspect, the dielectric substrate includes a first surface and a second surface disposed opposite to each other. The number of first radiating arms is four, arranged around the central region of the dielectric substrate and forming two cross dipoles. One cross dipole is disposed on the first surface, and the other on the second surface. The first ends of the two first radiating arms in each cross dipole are connected by a phase delay line. The feed unit is a coaxial cable, including an outer conductor, an inner conductor, and an insulator filling the space between the outer and inner conductors. The coaxial cable extends to the central region of the dielectric substrate. The outer conductor is electrically connected to a first radiating arm located on the second surface, and the inner conductor passes through the dielectric substrate and is electrically connected to a first radiating arm located on the first surface. The two first radiating arms electrically connected to the inner and outer conductors, respectively, extend in the same direction. This configuration allows the outer conductor to effectively shield against external electromagnetic interference and prevent internal signals from radiating outwards, thereby improving the electromagnetic compatibility of the circularly polarized antenna. Simultaneously, it allows for a more compact structure of the feed unit of the circularly polarized antenna, avoiding the feed unit occupying other space and increasing the overall size of the circularly polarized antenna.

[0016] In some embodiments of the first aspect, on the first plate, a first end of a first radiating arm is provided with a first connecting flange, the first connecting flange extending into the area enclosed by the phase delay line and abutting against the inner conductor; on the second plate, a first end of a first radiating arm is provided with a second connecting flange, the second connecting flange extending into the area enclosed by the phase delay line and abutting against the outer conductor. This arrangement facilitates the electrical connection of the power supply unit to the corresponding first radiating arm.

[0017] Secondly, embodiments of this application provide an antenna device, including an antenna array, the antenna array including a plurality of circularly polarized antennas as described in the first aspect.

[0018] The beneficial effects of the antenna device in this embodiment are the same as those of the circularly polarized antenna in the first aspect, and will not be repeated here.

[0019] In some embodiments of the second aspect, the number of circularly polarized antennas is three, arranged in a triangular or L-shaped pattern. The antenna device further includes a phase adjustment unit and a switching unit. The phase adjustment unit has a first input port, a second input port, a first output port, and a second output port. The first and second input ports are respectively used for electrical connection to a communication transceiver. The first and second output ports are respectively used for outputting signals with a 90° phase difference. The switching unit is electrically connected to the first input port, the second input port, and the three circularly polarized antennas, respectively. The switching unit is used to make the first and second input ports electrically connected to any two circularly polarized antennas in a one-to-one correspondence. With this configuration, through phase adjustment by the phase adjustment unit and state switching by the switching unit, the antenna device can generate multiple beams, thereby achieving zenith wide-beam coverage and meeting the communication needs of vehicles under different orientation conditions.

[0020] In some embodiments of the second aspect, the phase adjustment unit is a 3dB bridge. This configuration reduces signal interference between different ports of the phase adjustment unit.

[0021] In some embodiments of the second aspect, the switching unit is a double-pole four-throw switch, which has two input contacts and four output contacts. The two input contacts are respectively connected to the first input port and the second input port, and the three output contacts are respectively electrically connected to three circularly polarized antennas. This configuration can improve the isolation effect between different signal channels in the switching unit.

[0022] In some embodiments of the second aspect, the first input port is used to connect to a satellite communication transceiver, and the second input port is used to connect to a cellular communication transceiver. With this configuration, the antenna device can perform both satellite communication to meet the vehicle's satellite communication needs under different orientations, and cellular communication to meet the vehicle's cellular communication needs under different orientations, providing good communication performance in scenarios such as underground parking lots and remote control applications.

[0023] Thirdly, embodiments of this application provide a vehicle, including a vehicle body and the antenna device described in the second aspect, wherein the antenna device is disposed on the vehicle body.

[0024] The beneficial effects of the vehicle in this embodiment are the same as those of the circularly polarized antenna in the first aspect, and will not be repeated here.

[0025] In some embodiments of the third aspect, the antenna device is mounted on the top of the vehicle body. This configuration can improve the communication performance between the antenna device and the satellite. Attached Figure Description

[0026] Figure 1 is a schematic diagram of the structure of the circularly polarized antenna in the first embodiment of this application;

[0027] Figure 2 is a top view of the circularly polarized antenna shown in Figure 1;

[0028] Figure 3 is a bottom view of the circularly polarized antenna shown in Figure 1 after the floor has been removed;

[0029] Figure 4 is a schematic diagram of the structure of the circularly polarized antenna shown in Figure 1 after the dielectric substrate is removed;

[0030] Figure 5a is an AA cross-sectional view of the circularly polarized antenna shown in Figure 2;

[0031] Figure 5b is a magnified view of a portion of Figure 5a;

[0032] Figure 6a shows the current distribution of the circularly polarized antenna shown in Figure 1 when it is in the first resonance.

[0033] Figure 6b shows the current distribution of the circularly polarized antenna shown in Figure 1 when it is at the second resonance.

[0034] Figure 6c shows the current distribution of the circularly polarized antenna shown in Figure 1 when it is at the third resonance.

[0035] Figure 6d shows the current distribution of the circularly polarized antenna shown in Figure 1 when it is at the fourth resonance.

[0036] Figure 7a shows the S11 and antenna efficiency curve of the circularly polarized antenna shown in Figure 1.

[0037] Figure 7b is a graph of the zenith axial ratio of the circularly polarized antenna shown in Figure 1.

[0038] Figure 7c is a curve showing the minimum left-hand circular gain of the circularly polarized antenna shown in Figure 1 when the beam elevation angle is 10° / 20°.

[0039] Figure 8a shows the 3D radiation pattern of the circularly polarized antenna shown in Figure 1 at 1.52 GHz;

[0040] Figure 8b shows the 3D radiation pattern shown in Figure 8a in the XOZ section.

[0041] Figure 8c shows the 3D radiation pattern shown in Figure 8a in the YOZ section.

[0042] Figure 8d shows the 3D radiation pattern of the circularly polarized antenna shown in Figure 1 at 2.2 GHz;

[0043] Figure 8e shows the 3D radiation pattern shown in Figure 8d in the XOZ section.

[0044] Figure 8f shows the 3D radiation pattern shown in Figure 8d in the YOZ cross-section;

[0045] Figure 9 is a schematic diagram of the structure of the circularly polarized antenna in the second embodiment of this application;

[0046] Figure 10a is a top view of the circularly polarized antenna shown in Figure 9;

[0047] Figure 10b is a schematic diagram of the structure of the circularly polarized antenna shown in Figure 9 after the dielectric substrate is removed;

[0048] Figure 11a shows the S11 and antenna efficiency curve of the circularly polarized antenna shown in Figure 9.

[0049] Figure 11b is a graph of the zenith axial ratio of the circularly polarized antenna shown in Figure 9.

[0050] Figure 11c is a graph showing the maximum left-hand circular gain of the circularly polarized antenna shown in Figure 9;

[0051] Figure 11d is a curve showing the minimum left-hand circular gain of the circularly polarized antenna shown in Figure 9 when the beam elevation angle is 10° / 20°.

[0052] Figure 12a shows the 3D radiation pattern of the circularly polarized antenna shown in Figure 9 at 1.52 GHz;

[0053] Figure 12b shows the 3D radiation pattern shown in Figure 12a in the XOZ section.

[0054] Figure 12c shows the 3D radiation pattern shown in Figure 12a in the YOZ section.

[0055] Figure 12d shows the 3D radiation pattern of the circularly polarized antenna shown in Figure 9 at 2.2 GHz;

[0056] Figure 12e shows the 3D radiation pattern shown in Figure 12d in the XOZ section;

[0057] Figure 12f shows the 3D radiation pattern shown in Figure 12d in the YOZ cross-section;

[0058] Figure 13 is a schematic diagram of the vehicle structure in an embodiment of this application;

[0059] Figure 14 is a top view of the vehicle shown in Figure 13;

[0060] Figure 15 is a schematic diagram of the internal structure of the antenna device of the vehicle shown in Figure 13;

[0061] Figure 16 is a schematic block diagram of the antenna device in an embodiment of this application;

[0062] Figure 17 is a schematic diagram of the antenna beam pointing in the antenna device shown in Figure 16;

[0063] Figure 18 shows the beam pattern that the antenna device shown in Figure 16 can generate;

[0064] Figure 19 is a schematic diagram of the division of the vehicle's directional sector in an embodiment of this application;

[0065] Figure 20 is a schematic diagram of the change in the orientation angle of a vehicle when turning in an embodiment of this application;

[0066] Figure 21 is a comparison diagram of a single antenna (with one circularly polarized antenna) and an antenna device (i.e., multiple circularly polarized antennas) in the embodiments of this application.

[0067] Figure 22 shows a comparison of the beamwidth of a single antenna and the antenna device in the embodiment of this application;

[0068] Figure 23 shows the communication effect of the antenna device in the embodiment of this application under different beam elevation angles;

[0069] Figure 24 is a comparison diagram of the antenna gain of the antenna device in the embodiment of this application and the gain of a conventional cellular antenna;

[0070] Figure 25 is a schematic diagram of the internal structure of the antenna device in some other embodiments of this application. Detailed Implementation

[0071] Against the backdrop of the continuous development of modern wireless communication technology, circularly polarized antennas play a key role in many fields due to their unique performance advantages.

[0072] Circularly polarized antennas possess significant advantages, including reducing multipath interference, counteracting Faraday rotation caused by the ionosphere, and minimizing mismatch losses. In multipath interference scenarios, their circular polarization allows multipath signals to partially cancel each other out over time, effectively reducing interference. In scenarios involving ionospheric propagation, such as satellite communications, they can adapt to the polarization plane rotation caused by the ionosphere, ensuring stable signal transmission. Furthermore, their ability to receive signals with different polarizations reduces losses caused by polarization mismatch. These advantages have led to the widespread application of circularly polarized antennas in modern wireless communication systems such as satellite communications, satellite navigation systems, radio frequency identification (RFID), and wireless local area networks (WLANs).

[0073] Today, the demands on vehicle-mounted communications are increasing, requiring vehicles to have satellite communication capabilities to support multi-network satellite communication. Examples include the Tiantong satellite communication system (transmitter band: 1980–2010 MHz, receiver band: 2170–2200 MHz) and the Xingwang satellite communication system (transmitter band: 1668–1675 MHz, receiver band: 1518–1525 MHz). In a vehicle environment, to meet the needs of multi-network satellite communication, a wide-bandwidth circularly polarized antenna is required to effectively receive and transmit signals in different frequency bands, ensuring a stable communication connection with satellites while the vehicle is moving.

[0074] However, as shown in Table 1, while circularly polarized antennas in related technologies possess the advantage of wide-bandwidth beams, their large size makes them difficult to adapt to the trend of miniaturization in vehicle antennas. Within the limited space of a vehicle, a large antenna is not only inconvenient to install but may also affect the vehicle's aesthetics and performance. Therefore, there is an urgent need to develop a miniaturized circularly polarized antenna to meet the requirements of multi-network satellite communication in vehicles.

[0075] Table 1 shows the parameters of some circularly polarized antennas and the requirements for vehicle-mounted antennas in related technologies.

[0076] Where λ is the wavelength of the frequency point to the left of the 3dB axial ratio passband. In the antenna dimensions, a×b×c represents “length×width×height”.

[0077] To address this, this application provides a circularly polarized antenna, antenna device, and vehicle. By arranging parasitic radiating arms for grounding around the cross dipoles in the circularly polarized antenna, and having a small cross-sectional area at the grounding end, the electric length of the parasitic radiating arms is increased. When the overall electric length of the antenna radiator is constant, this helps to reduce the overall physical size of the radiator, thereby miniaturizing the circularly polarized antenna to meet the installation requirements of vehicle-mounted antennas.

[0078] Figure 1 is a schematic diagram of the circularly polarized antenna in the first embodiment of this application; Figure 2 is a top view of the circularly polarized antenna shown in Figure 1; Figure 3 is a bottom view of the circularly polarized antenna shown in Figure 1 after the ground plane 1 is removed; and Figure 4 is a schematic diagram of the circularly polarized antenna shown in Figure 1 after the dielectric substrate 2 is removed. As shown in Figures 1 to 4, the circularly polarized antenna includes a ground plane 1, a dielectric substrate 2, a first radiating arm 31, a parasitic radiating arm 32, and a feed unit 4.

[0079] As shown in Figure 1, the floor 1 can be a metal plate, such as a copper plate or an aluminum plate. In addition, the floor 1 can also be a composite electromagnetic material plate, such as adding conductive components such as metal particles or fibers to a substrate made of polymer matrix material.

[0080] Along the thickness direction H, the dielectric substrate 2 is spaced apart from the ground plate 1. The dielectric substrate 2 can be an FR-4 board (glass fiber epoxy resin copper clad laminate), a PTFE (polytetrafluoroethylene) board, a ceramic board, a liquid crystal polymer board, etc. As shown in Figure 1, the dielectric substrate 2 can be a rectangular board, such as a square board, but it is not limited to this. The dielectric substrate 2 can also be a circular board or other polygonal boards, such as a triangular board, a pentagonal board, etc.

[0081] As shown in Figure 1, the dielectric plate 2 and the base plate 1 can be supported by a supporting side plate 5. The supporting side plate 5 is located at the edge of the dielectric plate 2 and forms a cavity with the dielectric plate 2 and the base plate 1. Alternatively, the supporting side plate 5 can be omitted, and the space between the dielectric plate 2 and the base plate 1 can be filled with an insulating medium, which separates the dielectric plate 2 from the base plate 1.

[0082] As shown in Figures 1, 2, and 3, there are multiple first radiating arms 31, which together form at least one cross dipole 30. The first end of each first radiating arm 31 is located near the central region 21 of the dielectric substrate 2, and the second end of each first radiating arm 31 is located near the edge 22 of the dielectric substrate 2.

[0083] In some embodiments, as shown in Figures 1, 2, and 3, the dielectric substrate 2 includes a first substrate surface 2a and a second substrate surface 2b arranged opposite to each other. The number of first radiating arms 31 is four, namely first radiating arm 31a, first radiating arm 31b, first radiating arm 31c, and first radiating arm 31d. The first radiating arms 31a, 31b, 31c, and 31d are arranged around the central region 21 of the dielectric substrate 2 and form two cross dipoles 30. As shown in Figure 1, one cross dipole 30 (i.e., the cross dipole 30 formed by the first radiating arms 31a and 31b) is arranged on the first substrate surface 2a. As shown in Figure 3, the other cross dipole 30 (i.e., the cross dipole 30 formed by the first radiating arms 31c and 31d) is arranged on the second substrate surface 2b. The first ends of the two first radiating arms 31 in each cross dipole 30 are connected by a phase delay line 34.

[0084] Of course, there can also be two first radiating arms 31, which together form a cross dipole 30 and are disposed on the first plate surface 2a.

[0085] As shown in Figures 1, 3, and 4, there are multiple parasitic radiating arms 32, which are distributed along the circumference of the dielectric plate 2 at the edge 22 of the dielectric plate 2. Each parasitic radiating arm 32 is coupled to the first radiating arm 31 that is close to it. Each parasitic radiating arm 32 has a grounding end 3201 and an open end 3202. The grounding end 3201 is connected to the floor 1, and the open end 3202 is located at the edge 22 of the dielectric plate 2. The cross-sectional area of ​​the parasitic radiating arm 32 at the grounding end 3201 is smaller than the cross-sectional area at the open end 3202.

[0086] Specifically, the cross-sectional area of ​​the parasitic radiating arm 32 refers to the area of ​​the cross-section formed by the parasitic radiating arm 32 after it is cut by a plane perpendicular to the thickness direction of the floor 1. The open end 3202 and the grounding end 3201 are relative to whether or not they are grounded; the grounding end 3201 is grounded, and the open end 3202 is not grounded. The parasitic radiating arm 32 can be mounted on the supporting side plate 5.

[0087] In some embodiments, as shown in Figures 1 and 4, the number of parasitic radiation arms 32 can be equal to the number of first radiation arms 31. Multiple parasitic radiation arms 32 are coupled to multiple first radiation arms 31 in a one-to-one correspondence. For example, as shown in Figure 4, the multiple parasitic radiation arms 32 are parasitic radiation arms 32a, 32b, 32c, and 32d. First radiation arms 31a are coupled to parasitic radiation arms 32a, first radiation arms 31b are coupled to parasitic radiation arms 32b, first radiation arms 31c are coupled to parasitic radiation arms 32c, and first radiation arms 31d are coupled to parasitic radiation arms 32d.

[0088] Of course, the number of parasitic radiation arms 32 can also be different from the number of first radiation arms 31. For example, the number of parasitic radiation arms 32 can be twice the number of first radiation arms 31.

[0089] As shown in Figures 3 and 4, the power supply unit 4 is used to supply power to each of the first radiating arms 31.

[0090] In this embodiment of the circularly polarized antenna, by setting the cross-sectional area of ​​the parasitic radiating arm 32 at the grounding end 3201 to be smaller than that at the open end 3202, it is equivalent to making the cross-sectional area of ​​the parasitic radiating arm 32 at the grounding end 3201 smaller. Thus, according to the current distribution pattern on the parasitic radiating arm 32 during the operation of the circularly polarized antenna—that is, the grounding end 3201 is the point of maximum current and the open end 3202 is the point of minimum current—reducing the cross-sectional area of ​​the parasitic radiating arm 32 at the point of maximum current increases the inductance of the parasitic radiating arm 32. Since the resonant frequency of the antenna is inversely proportional to the inductance of the radiator, increasing the inductance of the parasitic radiating arm 32 can improve the circular polarization... The reduced resonant frequency of the circularly polarized antenna is equivalent to increasing the electrical length of the radiator (here, the radiator refers to the first radiating arm 31 and the parasitic radiating arm 32) in the circularly polarized antenna. Therefore, the physical length of the radiator does not need to be designed to be so large, which helps to reduce the volume of the circularly polarized antenna to meet the installation requirements of vehicle antennas. For example, compared with the circularly polarized antenna in the related technology [3], the antenna size of the circularly polarized antenna in this embodiment can be reduced from 0.28λ×0.28λ×0.11λ to 0.2λ×0.2λ×0.09λ, and the antenna layout area is reduced by 49%, which greatly reduces the area occupied by the circularly polarized antenna and helps to miniaturize the circularly polarized antenna product.

[0091] In some embodiments, as shown in FIG1 and FIG4, the dielectric plate 2 is a polygonal plate having multiple edges 22 and multiple corners 23. The multiple edges 22 are edge 22a, edge 22b, edge 22c and edge 22d, and the corners 23 are formed at the junction of two adjacent edges 22.

[0092] Each parasitic radiating arm 32 is located at a corresponding corner 23 and forms a radiating arm group 33 with the adjacent first radiating arm 31. For example, as shown in Figures 1, 3 and 4, the parasitic radiating arm 32a and the first radiating arm 31a form a radiating arm group 33; the parasitic radiating arm 32b and the first radiating arm 31b form a radiating arm group 33; the parasitic radiating arm 32c and the first radiating arm 31c form a radiating arm group 33; and the parasitic radiating arm 32d and the first radiating arm 31d form a radiating arm group 33.

[0093] In the radiating arm group 33, the parasitic radiating arm 32 overlaps in size with the first radiating arm 31 in both the length direction and the width direction. For example, as shown in Figure 2, from the top view of the circularly polarized antenna, in the radiating arm group 33 formed by the parasitic radiating arm 32b and the first radiating arm 31b, along the length direction X of the first radiating arm 31b, the orthographic projections of the first radiating arm 31b and the parasitic radiating arm 32b on their corresponding edges 22b overlap by at least a portion; along the width direction Y of the first radiating arm 31b, the orthographic projections of the first radiating arm 31b and the parasitic radiating arm 32b on their corresponding edges 22c overlap by at least a portion.

[0094] The length direction of the first radiating arm 31 refers to the direction from the first end of the first radiating arm 31 to the second end, or from the second end of the first radiating arm 31 to the first end. The width direction of the first radiating arm 31 is perpendicular to the length direction of the first radiating arm 31 and the thickness direction H of the dielectric plate 2.

[0095] This configuration allows the parasitic radiating arm 32 to be coupled to the first radiating arm 31 in both the length and width directions. This increases the coupling area between the parasitic radiating arm 32 and the first radiating arm 31, increases the coupling capacitance between them, and extends the electrical length of the first radiating arm 31. Thus, when the electrical length requirement of the first radiating arm 31 is fixed, the physical size of the first radiating arm 31 does not need to be set too large, which helps to reduce the volume of the circularly polarized antenna.

[0096] In some embodiments, as shown in Figures 1 and 4, the parasitic radiating arm 32 includes a first arm segment 321 and a second arm segment 322. The second arm segment 322 is connected between the first arm segment 321 and the ground plane 1. The cross-sectional area of ​​the second arm segment 322 is smaller than that of the first arm segment 321. The open end 3202 is located in the first arm segment 321, and the ground end 3201 is located in the second arm segment 322. That is, the cross-sectional area of ​​the first arm segment 321 is set to be larger, and the cross-sectional area of ​​the second arm segment 322 is set to be smaller. By setting the cross-sectional area of ​​the first arm segment 321 to be larger, it is beneficial to increase the coupling efficiency between the parasitic radiating arm 32 and the corresponding first radiating arm 31; by setting the cross-sectional area of ​​the second arm segment 322 to be smaller, it is beneficial to increase the inductance of the parasitic radiating arm 32. Thus, while ensuring the coupling efficiency between the parasitic radiating arm 32 and the corresponding first radiating arm 31, it is beneficial to reduce the size of the circularly polarized antenna.

[0097] To optimize the axial ratio of the circularly polarized antenna, in some embodiments, as shown in Figures 1 and 4, both the first arm segment 321 and the second arm segment 322 are rectangular sheet structures. The length of the short side of the second arm segment 322 is less than the length of the long side of the first arm segment 321. The short side of the second arm segment 322 is connected to the middle of the long side of the first arm segment 321 (e.g., the midpoint of the long side). That is, the grounding position of the first arm segment 321 is located at the middle of the long side of the first arm segment 321. With this setting, the electric and magnetic field distributions of the circularly polarized antenna can be better adjusted, making the amplitudes of the two orthogonal polarization components generated by the circularly polarized antenna closer to equal and the phase difference closer to 90°. This can balance the energy radiation of different polarization directions and thus optimize the axial ratio of the circularly polarized antenna.

[0098] To optimize the axial ratio of the circularly polarized antenna, in some embodiments, as shown in Figures 1 and 2, a notch 311 is provided at the first end of each first radiating arm 31. By providing the notch 311, the current path on the first radiating arm 31 changes, which alters the current distribution on the first radiating arm 31. This adjusts the distribution of the electric field generated in the space around the circularly polarized antenna in two orthogonal directions, thereby optimizing the axial ratio of the circularly polarized antenna.

[0099] In some embodiments, the feed unit 4 can be a coaxial cable, as shown in Figures 4, 5a, and 5b. Figure 5a is an AA cross-sectional view of the circularly polarized antenna shown in Figure 2, and Figure 5b is a partial enlarged view of Figure 5a. The feed unit 4 includes an outer conductor 41, an inner conductor 42, and an insulator 43 filling the space between the outer conductor 41 and the inner conductor 42. The coaxial cable extends to the central region 21 of the dielectric substrate 2, and the outer conductor 41 is electrically connected to a first radiating arm 31 located on the second plate surface 2b. The inner conductor 42 passes through the dielectric substrate 2 and is electrically connected to a first radiating arm 31 located on the first plate surface 2a. The two first radiating arms 31, which are electrically connected to the inner conductor 42 and the outer conductor 41 respectively, extend in the same direction. For example, as shown in Figures 4 and 5b, the first radiating arm 31c is electrically connected to the outer conductor 41, and the first radiating arm 31a is electrically connected to the inner conductor 42. Both the first radiating arms 31c and the first radiating arm 31a extend along the Y direction.

[0100] By configuring the feed unit 4 as a coaxial cable, and the coaxial cable including an outer conductor 41, an inner conductor 42, and an insulator 43, the outer conductor can effectively shield against external electromagnetic interference and prevent internal signals from radiating outward, thereby improving the electromagnetic compatibility of the circularly polarized antenna. Furthermore, the coaxial cable extends to the central region 21 of the dielectric substrate 2 and is electrically connected to the first radiating arms 31 on the first plate surface 2a and the second plate surface 2b, respectively. This allows for a more compact structure of the feed unit 4 of the circularly polarized antenna, preventing the feed unit 4 from occupying other space and increasing the size of the circularly polarized antenna.

[0101] In some embodiments, as shown in FIG4, the first radiating arm 31a is electrically connected to the inner conductor 42, and the phase of the first radiating arm 31a can be 0°. The first radiating arm 31b is electrically connected to the first radiating arm 31a through a phase delay line 34, and the phase of the first radiating arm 31b lags behind the phase of the first radiating arm 31a by 90°. The first radiating arm 31c is electrically connected to the outer conductor 41, and the phase of the first radiating arm 31c lags behind the phase of the first radiating arm 31a by 180°. The first radiating arm 31d is electrically connected to the first radiating arm 31c through a phase delay line 34, and the phase of the first radiating arm 31d lags behind the phase of the first radiating arm 31c by 90°.

[0102] In some embodiments, as shown in Figures 1 and 4, on the first plate surface 2a, a first connecting flange 312 is provided at the first end of a first radiating arm 31 (e.g., a first radiator 31a), the first connecting flange 312 extends into the area enclosed by the phase delay line 34 and abuts against the inner conductor 42; as shown in Figures 3 and 4, on the second plate surface 2b, a second connecting flange 313 is provided at the first end of a first radiating arm 31, the second connecting flange 313 extends into the area enclosed by the phase delay line 34 and abuts against the outer conductor 41.

[0103] By providing a first connecting flange 312 and a second connecting flange 313, which serve as intermediate connections, the power supply unit 4 can be easily electrically connected to its corresponding first radiating arm 31. Simultaneously, the first connecting flange 312 and the second connecting flange 313 extend into the area enclosed by the corresponding phase delay line 34, thus preventing interference caused by the intersection of the first connecting flange 312, the second connecting flange 313 and the corresponding phase delay line 34.

[0104] As shown in Figures 1 and 3, the phase delay line 34 can be an arc-shaped line, but it is not limited to this; the phase delay line 34 can also be a broken line.

[0105] The aforementioned power supply unit 4 is not limited to a coaxial cable; it can also be a microstrip line.

[0106] Figure 6a shows the current distribution of the circularly polarized antenna shown in Figure 1 at the first resonance, Figure 6b shows the current distribution of the circularly polarized antenna shown in Figure 1 at the second resonance, Figure 6c shows the current distribution of the circularly polarized antenna shown in Figure 1 at the third resonance, and Figure 6d shows the current distribution of the circularly polarized antenna shown in Figure 1 at the fourth resonance.

[0107] In some embodiments, the circularly polarized antenna has a first resonance, a second resonance, a third resonance, and a fourth resonance. The first resonance is a resonance at 1.48 GHz, the second resonance is a resonance at 1.54 GHz, the third resonance is a resonance at 2.2 GHz, and the fourth resonance is a resonance at 3 GHz.

[0108] As shown in Figure 6a, the first resonance of the circularly polarized antenna is generated by the cross dipole 30 and the parasitic radiating arm 32. When the circularly polarized antenna is at the first resonance, the current flow direction of the cross dipole 30 and the two adjacent parasitic radiating arms 32 is the same (i.e., the counterclockwise direction shown in Figure 6a). The parasitic radiating arm 32 plays the role of extending the electrical length of the first radiating arm 31 that is coupled.

[0109] As shown in Figure 6b, the second resonance of the circularly polarized antenna is also generated by the cross dipole 30 and the parasitic radiating arm 32. When the circularly polarized antenna is in the second resonance, the current flow direction of the cross dipole 30 and the two adjacent parasitic radiating arms 32 is the same, and the parasitic radiating arm 32 plays the role of extending the electrical length of the adjacent first radiating arm 31.

[0110] As shown in Figure 6c, the third resonance of the circularly polarized antenna is also generated by the cross dipole 30 and the parasitic radiating arm 32. When the circularly polarized antenna is at the third resonance, the current flow direction of two of the parasitic radiating arms 32 is the same as that of the adjacent first radiating arm 31, while the current flow direction of the other two parasitic radiating arms 32 is opposite to that of the adjacent first radiating arm 31. The parasitic radiating arm 32 plays the role of adjusting the current amplitude of the two cross dipoles 30.

[0111] As shown in Figure 6d, the fourth resonance of the circularly polarized antenna is generated by the cross dipole 30 itself. When the circularly polarized antenna is at the fourth resonance, the current is mainly concentrated on the cross dipole 30.

[0112] Figure 7a shows the S11 and antenna efficiency curves of the circularly polarized antenna shown in Figure 1. Figure 7b shows the zenith axis ratio curve of the circularly polarized antenna shown in Figure 1. Figure 7c shows the minimum left-hand gain curve of the circularly polarized antenna shown in Figure 1 when the beam elevation angle is 10° / 20°.

[0113] As shown in Figures 7a, 7b, and 7c, within the transmit and receive frequency bands of the StarNet satellite communication system, the antenna efficiency of the circularly polarized antenna is > -1.0dB, the zenith axial ratio of the circularly polarized antenna is < 5.2dB, and the left-hand gain is ≥ -2.8dBic at elevation angles above 20° (i.e., Theta is 70°).

[0114] Within the transceiver frequency band of the Tiantong satellite communication system, the antenna efficiency of the circularly polarized antenna is > -0.6dB, the zenith axial ratio of the circularly polarized antenna is < 2.8dB, and the left-hand gain is ≥ -1.6dBic at elevation angles above 20° (i.e., Theta is 70°).

[0115] Figure 8a shows the 3D radiation pattern of the circularly polarized antenna shown in Figure 1 at 1.52 GHz. Figure 8b shows the radiation pattern of the 3D radiation pattern shown in Figure 8a in the XOZ section. Figure 8c shows the radiation pattern of the 3D radiation pattern shown in Figure 8a in the YOZ section. As can be seen from the radiation patterns shown in Figures 8a, 8b, and 8c, the circularly polarized antenna in the first embodiment of this application exhibits multiple lobes, upward radiation, and a wide beam at 1.52 GHz, which can better meet the needs of satellite communication.

[0116] Figure 8d shows the 3D radiation pattern of the circularly polarized antenna shown in Figure 1 at 2.2 GHz. Figure 8e shows the radiation pattern of the 3D radiation pattern shown in Figure 8d in the XOZ section, and Figure 8f shows the radiation pattern of the 3D radiation pattern shown in Figure 8d in the YOZ section. As can be seen from the radiation patterns shown in Figures 8d, 8e, and 8f, the circularly polarized antenna in the first embodiment of this application exhibits multiple lobes, upward radiation, and a wide beam at 2.2 GHz, which can better meet the needs of satellite communication.

[0117] Figure 9 is a schematic diagram of the circularly polarized antenna in the second embodiment of this application. Figure 10a is a top view of the circularly polarized antenna shown in Figure 9. Figure 10b is a schematic diagram of the circularly polarized antenna shown in Figure 9 after the dielectric substrate 2 has been removed. The main difference between the circularly polarized antenna in the second embodiment of this application and the circularly polarized antenna in the first embodiment is that the positional relationship between the parasitic radiating arm 32 and the adjacent first radiating arm 31 is different, as described below:

[0118] As shown in Figures 9 and 10a, the dielectric plate 2 is a polygonal plate with multiple edges 22. Each parasitic radiating arm 32 is located at the corresponding edge 22 and forms a radiating arm group 33 with the adjacent first radiating arm 31.

[0119] For example, as shown in Figures 9 and 10a, the dielectric plate 2 has four edges 22, namely edge 22a, edge 22b, edge 22c and edge 22d, and four parasitic radiating arms 32, namely parasitic radiating arms 32a, parasitic radiating arms 32b, parasitic radiating arms 32c and parasitic radiating arms 32d. Parasitic radiating arms 32a and the first radiating arm 31a form a radiating arm group 33; parasitic radiating arms 32b and the first radiating arm 31b form a radiating arm group 33; parasitic radiating arms 32c and the first radiating arm 31c form a radiating arm group 33; parasitic radiating arms 32d and the first radiating arm 31d form a radiating arm group 33.

[0120] As shown in Figures 10a and 10b, in the radiating arm group 33, in the length direction of the first radiating arm 31, the size of the parasitic radiating arm 32 is smaller than the size of the first radiating arm 31, and the size of the parasitic radiating arm 32 completely overlaps with that of the first radiating arm 31.

[0121] For example, as shown in Figure 10a, from the top view of the circularly polarized antenna, in the radiating arm group 33 formed by the parasitic radiating arm 32b and the first radiating arm 31b, along the width direction Y of the first radiating arm 31b, the orthographic projection of the parasitic radiating arm 32b on the edge 22b completely coincides with the orthographic projection of the first radiating arm 31b on the edge 22b.

[0122] This configuration helps to increase the coupling area between the parasitic radiating arm 32 and the corresponding first radiating arm 31, increases the coupling capacitance between the parasitic radiating arm 32 and the first radiating arm 31, and extends the electrical length of the first radiating arm 31. Thus, when the electrical length requirement of the first radiating arm 31 is fixed, the physical size of the first radiating arm 31 does not need to be set too large, which helps to reduce the volume of the circularly polarized antenna.

[0123] In some embodiments, as shown in Figures 9 and 10b, the parasitic radiation arm 32 includes a first arm segment 321 and a second arm segment 322. The second arm segment 322 is connected between the first arm segment 321 and the floor 1. The cross-sectional area of ​​the second arm segment 322 is smaller than that of the first arm segment 321. The open end 3202 is located in the first arm segment 321, and the grounding end 3201 is located in the second arm segment 322. That is, the cross-sectional area of ​​the first arm segment 321 is set to be larger, and the cross-sectional area of ​​the second arm segment 322 is set to be smaller.

[0124] In some embodiments, as shown in Figures 9 and 10b, both the first arm segment 321 and the second arm segment 322 are rectangular sheet structures. The length of the short side of the second arm segment 322 is less than the length of the long side of the first arm segment 321. The short side of the second arm segment 322 is connected to the middle part (e.g., the midpoint of the long side) of the first arm segment 321. The second arm segment 322 and the first arm segment 321 together form a T-shaped sheet structure.

[0125] Figure 11a shows the S11 and antenna efficiency curves of the circularly polarized antenna shown in Figure 9. Figure 11b shows the zenith axis ratio curve of the circularly polarized antenna shown in Figure 9. Figure 11c shows the maximum left-hand circular gain curve of the circularly polarized antenna shown in Figure 9. Figure 11d shows the minimum left-hand circular gain curve of the circularly polarized antenna shown in Figure 9 when the beam elevation angle is 10° / 20°.

[0126] As shown in Figures 11a to 11d, within the transmit and receive frequency bands of the StarNet satellite communication system, the antenna efficiency of the circularly polarized antenna is > -0.9dB, the zenith axial ratio of the circularly polarized antenna is < 5dB, and the left-hand gain is ≥ -2.4dBic at elevation angles above 20° (i.e., Theta is 70°).

[0127] Within the transceiver frequency band of the Tiantong satellite communication system, the antenna efficiency of the circularly polarized antenna is > -0.6dB, the zenith axial ratio of the circularly polarized antenna is < 3dB, and the left-hand gain is ≥ -1.2dBic at elevation angles above 20° (i.e., Theta is 70°).

[0128] Figure 12a shows the 3D radiation pattern of the circularly polarized antenna shown in Figure 9 at 1.52 GHz. Figure 12b shows the radiation pattern of the 3D radiation pattern shown in Figure 12a in the XOZ section. Figure 12c shows the radiation pattern of the 3D radiation pattern shown in Figure 12a in the YOZ section. As can be seen from the radiation patterns shown in Figures 12a, 12b, and 12c, the circularly polarized antenna in the second embodiment of this application exhibits multiple lobes, upward radiation, and a wide beam at 1.52 GHz, which can better meet the needs of satellite communication.

[0129] Figure 12d shows the 3D radiation pattern of the circularly polarized antenna shown in Figure 9 at 2.2 GHz. Figure 12e shows the radiation pattern of the 3D radiation pattern shown in Figure 12d in the XOZ section. Figure 12f shows the radiation pattern of the 3D radiation pattern shown in Figure 12d in the YOZ section. As can be seen from the radiation patterns shown in Figures 12d, 12e, and 12f, the circularly polarized antenna in the second embodiment of this application exhibits multiple lobes, upward radiation, and a wide beam at 2.2 GHz, which can better meet the needs of satellite communication.

[0130] The above is an introduction to the circularly polarized antenna in the embodiments of this application. The following is an introduction to the application scenarios of the circularly polarized antenna in the embodiments of this application.

[0131] Figure 13 is a structural schematic diagram of the vehicle in an embodiment of this application, Figure 14 is a top view of the vehicle shown in Figure 13, and Figure 15 is a schematic diagram of the internal structure of the antenna device 1000 of the vehicle shown in Figure 13. As shown in Figures 13-15, the vehicle includes a vehicle body 2000 and an antenna device 1000, which is mounted on the vehicle body 2000. As shown in Figure 15, the antenna device 1000 includes an antenna array 200, which includes the circularly polarized antenna 100 described in any of the above embodiments. With this configuration, the vehicle can conduct satellite communication via the antenna device 1000 on the vehicle body 2000 during operation.

[0132] The aforementioned vehicles can be SUVs, MPVs, sedans, motorhomes, vans, buses, trucks, etc., without specific limitations.

[0133] To improve the communication performance between the antenna device 1000 and the satellite, in some embodiments, as shown in Figures 13 and 14, the antenna device 1000 is disposed on the top of the vehicle body 2000. For example, as shown in Figures 13 and 14, the antenna device 1000 can be disposed on the outer surface of the top wall of the vehicle body 2000.

[0134] Of course, it is not limited to this. The antenna device 1000 can be embedded in the top wall of the vehicle body 2000 or set in other parts of the vehicle body 2000, depending on the actual situation.

[0135] To better protect the antenna array 200, in some embodiments, as shown in Figures 13, 14 and 15, the antenna device 1000 further includes a housing 600, in which the antenna array 200 is disposed.

[0136] In some embodiments, as shown in Figures 14 and 15, there are three circularly polarized antennas 100, namely circularly polarized antenna 100a, circularly polarized antenna 100b and circularly polarized antenna 100c, wherein, as shown in Figure 15, the three circularly polarized antennas 100 are arranged in a triangular pattern.

[0137] In some embodiments, as shown in Figures 14 and 15, circularly polarized antennas 100b and 100c are arranged along the width direction W of the vehicle body 2000 to form an antenna array, and circularly polarized antenna 100a and the antenna array are arranged along the length direction L of the vehicle body 2000.

[0138] In some embodiments, as shown in Figure 15, along the arrangement direction of the circularly polarized antennas 100b and 100c (e.g., the width direction W of the vehicle body 2000), the circularly polarized antenna 100a is positioned close to the circularly polarized antenna 100b. For example, as shown in Figure 15, the circularly polarized antennas 100c are arranged symmetrically about the central plane F, and the center point O of the circularly polarized antenna 100a is located on the side of the central plane F closest to the circularly polarized antenna 100b.

[0139] In addition to being arranged in a triangular pattern, the three circularly polarized antennas 100 can also be arranged in an L-shape.

[0140] In some embodiments, as shown in FIG15, a first circuit board 800 is provided inside the housing 600, and circularly polarized antennas 100a, 100b and 100c are disposed on the carrier substrate of the first circuit board 800.

[0141] Figure 16 is a principle block diagram of the antenna device 1000 in the embodiment of this application, Figure 17 is a principle diagram of the antenna beam pointing in the antenna device 1000 shown in Figure 16, and Figure 18 is a beam pattern that the antenna device 1000 shown in Figure 16 can generate.

[0142] In some embodiments, as shown in Figures 15 and 16, the antenna device further includes a phase adjustment unit 300 and a switch unit 400. The phase adjustment unit 300 has a first input port I1, a second input port I2, a first output port P1, and a second output port P2. The first input port I1 and the second input port I2 are respectively used to electrically connect to a communication transceiver. The first output port P1 and the second output port P2 are respectively used to output signals with a phase difference of 90°. The switch unit 400 is electrically connected to the first input port I1, the second input port I2, and the three circularly polarized antennas 100, respectively. The switch unit 400 is used to make the first input port I1 and the second input port I2 electrically connected to any two circularly polarized antennas 100 in a one-to-one correspondence.

[0143] By switching the state of the switch unit 400, the phase adjustment unit 300 can be electrically connected to any two circularly polarized antennas 100, enabling the two circularly polarized antennas 100 electrically connected to the phase adjustment unit 300 to operate. Since the output port P1 and the second output port P2 are used to output signals with a 90° phase difference, as shown in Figure 17, the beams generated by the two circularly polarized antennas 100 electrically connected to the phase adjustment unit 300 will point to the side where the phase-lagging circularly polarized antenna 100 is located. Thus, through the phase adjustment of the phase adjustment unit 300 and the state switching of the switch unit 400, the antenna device 1000 can generate multiple beams, such as the front beam, rear beam, left beam, right beam, upper left corner beam, and lower right corner beam shown in Figure 18, thereby achieving zenith wide beam coverage and meeting the communication needs of vehicles in different orientations.

[0144] In some embodiments, as shown in Figures 15, 16, and 18, when the switching unit 400 switches the circularly polarized antennas 100a and 100b to be electrically connected to the first input port I1 and the second input port I2 of the phase adjustment unit 300, the antenna device 1000 can generate front and rear beams (i.e., front beam and rear beam); when the switching unit 400 switches the circularly polarized antennas 100b and 100c to be electrically connected to the first input port I1 and the second input port I2 of the phase adjustment unit 300, the antenna device 1000 can generate left and right beams (i.e., left beam and right beam); when the switching unit 400 switches the circularly polarized antennas 100a and 100c to be electrically connected to the first input port I1 and the second input port I2 of the phase adjustment unit 300, the antenna device 1000 can generate diagonal beams (i.e., upper left corner beam and lower right corner beam).

[0145] In some embodiments, as shown in FIG16, the first input port I1 is used for electrical connection with the satellite communication transceiver 510, wherein the satellite communication transceiver 510 can be a Tianwang satellite communication transceiver or a Tiantong satellite communication transceiver; the second input port I2 is used for electrical connection with the cellular communication transceiver 520. With this configuration, the antenna device 1000 can perform both satellite communication to meet the satellite communication needs of the vehicle under different orientations, and cellular communication to meet the cellular communication needs of the vehicle under different orientations, providing good communication performance in scenarios such as underground parking lots and remote control applications.

[0146] In some embodiments, the vehicle can determine its orientation using sensors such as GNSS positioning and gyroscopes, so that the beam of the antenna device 1000 is aligned with the satellite.

[0147] In order to reduce signal interference between different ports of the phase adjustment unit 300, in some embodiments, as shown in FIG16, the phase adjustment unit 300 is a 3dB bridge.

[0148] Of course, in addition to the 3dB bridge, the phase adjustment unit 300 can also be a phase shifter, etc.

[0149] To improve the isolation effect between different signal channels in the switch unit 400, in some embodiments, as shown in Figure 16, the switch unit 400 is a double-pole four-throw switch. The double-pole four-throw switch has two input contacts 410 and four output contacts 420. The two input contacts 410 are respectively connected to the first input port I1 and the second input port I2, and the three output contacts 420 are respectively electrically connected to the three circularly polarized antennas 100. When the double-pole four-throw switch is switched to a certain position, it can effectively isolate other unselected signal paths, thereby reducing mutual interference between signals.

[0150] In the antenna device 1000 of this application embodiment, the number of circularly polarized antennas 100 is not limited to three. For example, the number of circularly polarized antennas 100 can also be two. The two circularly polarized antennas 100 can be arranged side by side along the length direction L of the vehicle body 2000, or they can be arranged side by side along the width direction W of the vehicle body 2000. For another example, the number of circularly polarized antennas 100 can also be four. The four circularly polarized antennas 100 are arranged in a grid shape, that is, a 2*2 array.

[0151] Figure 19 is a schematic diagram of the division of the directional sector of the vehicle in the embodiment of this application, and Figure 20 is a schematic diagram of the change of the directional angle of the vehicle when turning in the embodiment of this application.

[0152] To address the beam switching issue of the antenna device 1000 during vehicle movement, in some embodiments, the vehicle orientation is refreshed and an antenna switch is performed every 100ms. Calculated based on a turning speed of 30km / h, the vehicle orientation angle changes by approximately 5°, as shown in Figure 19. The vehicle is divided into four 90° sectors (front, rear, left, and right), and the beamwidth of the antenna device 1000 is made greater than 100°. This ensures smooth switching of the circularly polarized antenna 100 within the antenna device 1000 without disconnection.

[0153] The approximately 5° change in the vehicle's orientation angle can be derived as follows, as shown in Figure 20: When a vehicle moves in a circle with a radius R of 10m at a speed of 30km / h, the distance traveled in 100ms is: 30km / h*100ms≈0.83m; the circumference of the circle = 2*3.14*10m = 62.8m, so the vehicle's angle phi = 360*0.83 / 62.8≈5°.

[0154] Figure 21 is a comparison diagram of a single antenna (with one circularly polarized antenna 100) and an antenna device 1000 (i.e., multiple circularly polarized antennas 100) in the embodiments of this application. Figure 22 is a comparison diagram of the beamwidth of a single antenna and an antenna device 1000 in the embodiments of this application. Figure 23 is a communication effect diagram of the antenna device 1000 in the embodiments of this application under different beam elevation angles.

[0155] As shown in Figures 21 and 22, the antenna gain of antenna device 1000 increases by 3 dB max at theta 70° (i.e., elevation angle 20°). As shown in Figure 23, the antenna gain of antenna device 1000 meets the requirements of satellite communication at beam elevation angles above 10° (theta = 80°), and antenna device 1000 has a wide beam and a relatively wide signal coverage area.

[0156] Figure 24 is a comparison diagram of the antenna gain of the antenna device 1000 in this embodiment and the gain of a conventional cellular antenna. Specifically, Figure 24(a) shows the antenna gain from 0° to 360° with an azimuth angle phi when the beam elevation angle is 20° (theta = 70°); Figure 24(b) shows the antenna gain from 0° to 360° with an azimuth angle phi when the beam elevation angle is 10° (theta = 80°); and Figure 24(c) shows the antenna gain from 0° to 360° with an azimuth angle phi when the beam elevation angle is 0° (theta = 90°, i.e., horizontal plane). As shown in Figure 24, taking cellular Band 3 as an example, the antenna gain of the antenna device 1000 is significantly improved in the low elevation angle region (theta 70°-90°) compared to the original cellular antenna (IFA / IL, etc.).

[0157] Figure 25 is a schematic diagram of the internal structure of the antenna device 1000 in some other embodiments of this application. As shown in Figure 25, the antenna device 1000 includes a housing 600, and a second circuit board 750, an antenna array 200, a cellular low-frequency antenna 710, and a cellular high-frequency antenna 720, all disposed within the housing 600. The antenna array 200, the cellular low-frequency antenna 710, and the cellular high-frequency antenna are disposed on a carrier substrate of the second circuit board 750. The number of cellular low-frequency antennas 710 can be two, and the number of cellular high-frequency antennas 720 can be four.

[0158] In some embodiments, as shown in FIG25, the antenna device 1000 further includes a power supply battery 730, which is disposed on the carrier substrate of the second circuit board 750 and is used to supply power to the antenna array 200, the cellular low-frequency antenna 710 and the cellular high-frequency antenna 720.

[0159] In some embodiments, as shown in FIG25, the antenna device 1000 further includes a connector 740, which is mounted on the housing wall of the housing 600.

[0160] While the description of this application is presented in conjunction with some embodiments, this does not mean that the features of this application are limited to this embodiment. On the contrary, the purpose of describing the application in conjunction with embodiments is to cover other options or modifications that may arise based on the claims of this application. To provide a thorough understanding of this application, many specific details are included in the above description. This application may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of this application, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0161] In the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0162] In the embodiments of this application, "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0163] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. The directional terms mentioned in the embodiments of this application, such as "upper," "lower," "left," "right," "inner," and "outer," are only for reference to the directions in the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of this application, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application. "Multiple" refers to at least two.

[0164] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0165] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A circularly polarized antenna, characterized in that, include: Floor (1); Medium plate (2), along the thickness direction of the medium plate (2), the medium plate (2) is spaced apart from the floor (1); Multiple first radiating arms (31) are disposed on the dielectric plate (2) and form at least one cross dipole (30). The first end of each first radiating arm (31) is disposed close to the central region (21) of the dielectric plate (2), and the second end of each first radiating arm (31) is disposed close to the edge (22) of the dielectric plate (2). Multiple parasitic radiating arms (32) are distributed along the circumference of the dielectric plate (2) at the edge (22) of the dielectric plate (2). Each parasitic radiating arm (32) is coupled to the first radiating arm (31) that is close to it. Each parasitic radiating arm (32) has a ground end (3201) and an open end (3202). The ground end (3201) is connected to the floor (1), and the open end (3202) is located at the edge (22) of the dielectric plate (2). The cross-sectional area of ​​the parasitic radiating arm (32) at the ground end (3201) is smaller than the cross-sectional area at the open end (3202). The power supply unit (4) is used to supply power to each of the first radiating arms (31).

2. The circularly polarized antenna according to claim 1, characterized in that, The parasitic radiation arm (32) includes a first arm segment (321) and a second arm segment (322). The second arm segment (322) is connected between the first arm segment (321) and the floor (1). The cross-sectional area of ​​the second arm segment (322) is smaller than that of the first arm segment (321). The open end (3202) is located in the first arm segment (321), and the grounding end (3201) is located in the second arm segment (322).

3. The circularly polarized antenna according to claim 2, characterized in that, Both the first arm segment (321) and the second arm segment (322) are rectangular sheet structures. The length of the short side of the second arm segment (322) is less than the length of the long side of the first arm segment (321). The short side of the second arm segment (322) is connected to the middle of the long side of the first arm segment (321).

4. The circularly polarized antenna according to claim 1 or 2, characterized in that, The dielectric plate (2) is a polygonal plate with multiple corners (23). Each parasitic radiating arm (32) is located at the corresponding corner (23) and forms a radiating arm group (33) with the adjacent first radiating arm (31). In the radiating arm group (33), the parasitic radiating arm (32) overlaps with the first radiating arm (31) in both the length direction and the width direction of the first radiating arm (31).

5. The circularly polarized antenna according to any one of claims 1 to 3, characterized in that, The dielectric plate (2) is a polygonal plate with multiple edges (22). Each parasitic radiating arm (32) is located at the corresponding edge (22) and forms a radiating arm group (33) with the adjacent first radiating arm (31). In the radiating arm group (33), in the length direction of the first radiating arm (31), the size of the parasitic radiating arm (32) is smaller than the size of the first radiating arm (31), and the size of the parasitic radiating arm (32) completely overlaps with that of the first radiating arm (31).

6. The circularly polarized antenna according to any one of claims 1 to 5, characterized in that, Each of the first radiating arms (31) has a notch (311) at its first end.

7. The circularly polarized antenna according to any one of claims 1 to 6, characterized in that, The dielectric plate (2) includes a first plate surface (2a) and a second plate surface (2b) arranged opposite to each other. There are four first radiation arms (31). The four first radiation arms (31) are arranged around the central region (21) of the dielectric plate (2) and form two cross dipoles (30). One cross dipole (30) is arranged on the first plate surface (2a) and the other cross dipole (30) is arranged on the second plate surface (2b). The first ends of the two first radiation arms (31) in each cross dipole (30) are connected by a phase delay line (34). The power supply unit (4) is a coaxial cable and includes an outer conductor (41), an inner conductor (42), and an insulator (43) filling the space between the outer conductor (41) and the inner conductor (42). The coaxial cable extends to the central region (21) of the dielectric plate (2), and the outer conductor (41) is electrically connected to a first radiating arm (31) located on the second plate surface (2b). The inner conductor (42) passes through the dielectric plate (2) and is electrically connected to a first radiating arm (31) located on the first plate surface (2a). The two first radiating arms (31) electrically connected to the inner conductor (42) and the outer conductor (41) extend in the same direction.

8. The circularly polarized antenna according to claim 7, characterized in that, On the first plate surface (2a), a first end of a first radiating arm (31) is provided with a first connecting flange (312), the first connecting flange (312) extends into the area enclosed by the phase delay line (34) and abuts against the inner conductor (42); On the second plate surface (2b), a first end of a first radiating arm (31) is provided with a second connecting flange (313), which extends into the area enclosed by the phase delay line (34) and abuts against the outer conductor (41).

9. An antenna device, characterized in that, It includes an antenna array (200) comprising a plurality of circularly polarized antennas (100) according to any one of claims 1 to 8.

10. The antenna device according to claim 9, characterized in that, The number of the circularly polarized antennas (100) is three, and the three circularly polarized antennas (100) are arranged in a triangular or L-shaped pattern; The antenna device further includes a phase adjustment unit (300) and a switch switching unit (400); The phase adjustment unit (300) has a first input port (I1), a second input port (I2), a first output port (P1), and a second output port (P2). The first input port (I1) and the second input port (I2) are respectively used to electrically connect to a communication transceiver; the first output port (P1) and the second output port (P2) are respectively used to output signals with a phase difference of 90°. The switch switching unit (400) is electrically connected to the first input port (I1), the second input port (I2), and the three circularly polarized antennas (100), respectively. The switch switching unit (400) is used to make the first input port (I1) and the second input port (I2) electrically connected to any two of the circularly polarized antennas (100) in a one-to-one correspondence.

11. The antenna device according to claim 10, characterized in that, The phase adjustment unit (300) is a 3dB bridge; And / or, the switch switching unit (400) is a double-pole four-throw switch, which has two input contacts (410) and four output contacts (420). The two input contacts (410) are respectively connected to the first input port (I1) and the second input port (I2), and the three output contacts (420) are respectively electrically connected to the three circularly polarized antennas (100).

12. The antenna device according to claim 10 or 11, characterized in that, The first input port (I1) is used to electrically connect to the satellite communication transceiver (510), and the second input port (I2) is used to electrically connect to the cellular communication transceiver (520).

13. A vehicle, characterized in that, The vehicle includes a vehicle body (2000) and an antenna device (1000) according to any one of claims 9 to 12, the antenna device (1000) being disposed on the vehicle body (2000).

14. The vehicle according to claim 13, characterized in that, The antenna device (1000) is located on the top of the vehicle body (2000).

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