CN114824788A - Vehicle-mounted antenna - Google Patents

Abstract

The invention provides a vehicle-mounted antenna, wherein a first metal sheet and a second metal sheet are arranged as a feeder line, the feeder line feeds energy to two first metal branches, each first metal branch is in a closed ring shape, a plurality of first edges are respectively connected through a plurality of second edges, and each first metal branch is equivalent to a dipole array formed by arranging a plurality of dipoles side by side; when the distance between two adjacent dipoles keeps a proper distance, the radiation intensity of the antenna can be superposed and enhanced in the normal direction of the plane where the first metal branch is located, superposed and offset in the horizontal parallel direction of the plane where the first metal branch is located, and in addition, the second metal branch group is combined to form an array effect, so that the gain of the vehicle-mounted antenna in the vertical plane of the plane where the first metal branch and the second metal branch are located is compressed and enhanced, the gain distribution in the normal direction of the plane where the metal branches are located is optimized, and the gain in the front and back ranges of the plane where the metal branches are located is larger than the gain in the left and right ranges.

Description

Vehicle-mounted antenna

Technical Field

The invention relates to the technical field of vehicle-mounted wireless communication, in particular to a vehicle-mounted antenna.

Background

In recent years, in-vehicle wireless communication systems have become more important for modern automobiles, and antenna systems have played a significant role as an important component of wireless communication systems. Today's car antennas are of various kinds to achieve different functions: such as cellular communications, Global Navigation Satellite System (GNSS), V2X (Vehicle-to-event), Satellite digital broadcasting (SDARS), etc. In addition, due to the particularity of the automobile platform, the radiation pattern of each functional antenna has specific requirements, for example, cellular communication requires that the radiation pattern is concentrated on a horizontal plane, GNSS communication requires that the radiation pattern is directed to a vertex and concentrated on an upper half plane so as to receive satellite signals, V2X communication requires that the radiation pattern has a horizontal plane omnidirectional pattern, and the front-back gain (the front-back direction is the front-back direction with the vehicle traveling direction, the front end is the front, and the rear end is the rear) of a general pattern is larger than the left-right gain of the vehicle. On the other hand, regarding the installation of the vehicle-mounted antenna, the mainstream is still highly integrated: i.e. the antennas with different functions are integrated in one module, such as in a shark fin on the roof of a vehicle, or in a box near the center console. In recent years, with the development of new technologies, especially the development of 5G technologies, many new innovations and changes are brought, such as the addition of multiple frequency bands in the frequency spectrum, such as 600M low frequency, and the generalization of multi-antenna MIMO technology. But at the same time also presents challenges to antenna design: such as isolation requirements between multiple antennas (especially low frequency bands); the effect of adjacent antennas on the antenna pattern when the antennas are arranged, etc.

Disclosure of Invention

In view of the above drawbacks of the prior art, an object of the present invention is to provide a vehicle-mounted antenna, which is used to solve the problem that in a vehicle-mounted wireless communication system in the prior art, the isolation of multiple antennas in the vehicle-mounted antenna system during the integration process, the influence of adjacent antennas on an antenna pattern, and the like reduce the integration effect.

To achieve the above and other related objects, the present invention provides a vehicle antenna, including:

a reference ground metal plate;

the first metal sheet and the second metal sheet are arranged above the reference ground metal plate and are arranged in parallel relatively; one end of the first metal sheet is electrically connected with a feed point, and one end of the second metal sheet is electrically connected with the reference ground metal plate;

a first metal branch group and a second metal branch group are arranged at intervals along the up-down direction of the first metal sheet and the second metal sheet;

the first metal branch group is arranged below and comprises: two first metal branches which are identical and distributed on two sides of the first metal sheet and the second metal sheet in a mirror image manner; the first metal branch knot comprises at least two first edges which are arranged in parallel relatively and at least two second edges which are respectively connected with two ends of the at least two first edges; one first edge is provided with a disconnection point at the middle position, one end of the disconnection point is electrically connected to the first metal sheet, the other end of the disconnection point is electrically connected to the second metal sheet, and the first metal branches are vertically and symmetrically distributed relative to the electrical connection points with the first metal sheet and the second metal sheet;

the second metal branch group is arranged above and comprises: two identical second metal branches distributed on two sides of the first metal sheet and the second metal sheet in a mirror image manner; the second metal branch segment comprises at least one third edge; and a disconnection point is arranged at the middle position of the third edge, one end of the disconnection point is electrically connected to the first metal sheet, the other end of the disconnection point is electrically connected to the second metal sheet, and the second metal branches are vertically and symmetrically distributed relative to the electrical connection points with the first metal sheet and the second metal sheet.

Optionally, an extending direction of the first edge is consistent with extending directions of the first metal sheet and the second metal sheet; the extending direction of the third side is consistent with the extending direction of the first metal sheet and the second metal sheet.

Optionally, a vertical distance between the first metal branch group and the second metal branch group is between 0.5 λ and 1.2 λ, λ is a medium wavelength of an operating frequency of the vehicle-mounted antenna, and the distance refers to a distance between an electrical connection point of the first metal branch group and the first metal sheet and the second metal sheet and an electrical connection point of the second metal branch group and the first metal sheet and the second metal sheet.

Optionally, the first metal sheet and the second metal sheet between the first metal branch group and the second metal branch group are provided with bent lines in the same shape or first inductance elements in the same size.

Optionally, a disconnection point is arranged on the second metal sheet, and the disconnection point is arranged below the electrical connection point of the first metal branch knot group, the first metal sheet and the second metal sheet; and two ends of the disconnection point are connected into a first capacitance element or a second inductance element or a parallel connection structure or a saw-tooth coupling structure of the first capacitance element and the second inductance element.

Optionally, the vehicle-mounted antenna further includes a third metal branch electrically connected to the reference ground metal plate, where the third metal branch is disposed near the first metal sheet and generates a coupling effect with the first metal sheet.

Optionally, the vehicle-mounted antenna further includes a third metal branch electrically connected to the reference ground metal plate; one end of the first metal sheet is electrically connected with the feed point through a fourth metal branch, and the third metal branch and the fourth metal branch generate a coupling effect.

Optionally, a third inductance element is connected in series on the first metal sheet below the electrical connection point of the first metal branch and the first metal sheet.

Optionally, the other end of the first metal sheet and/or the second metal sheet is electrically connected to a section of metal structure, and an included angle between the metal structure and the perpendicular direction of the extending direction of the first metal sheet and/or the second metal sheet is-30 to-30 °.

Optionally, when the vehicle-mounted antenna is multiplexed, a duplexer is connected to the feed point to split different frequency signals.

Optionally, the vehicle-mounted antenna is disposed on a PCB dielectric material, and the other first edge without a disconnection point is connected through a metal via.

Optionally, the first metal branch knot includes three first edges that are arranged in parallel relatively and four second edges that connect two ends of the three first edges respectively.

Optionally, the second metal branch comprises one of the third sides.

Optionally, the second metal branch knot includes two third edges and two fourth edges, the two third edges are arranged in parallel relatively, an extending direction of the two third edges is consistent with an extending direction of the first metal sheet and the second metal sheet, and the two fourth edges are respectively connected to two ends of the two third edges.

As described above, in the vehicle-mounted antenna according to the present invention, the first metal piece and the second metal piece are provided as the feeder line, the feeder line feeds energy to the two first metal branches, each of the first metal branches is in a closed loop shape, and the plurality of first sides are connected to each other by the plurality of second sides, so that each of the first metal branches corresponds to a dipole array in which the plurality of dipoles are arranged side by side; when the distance between two adjacent dipoles keeps a proper distance, the antenna radiation intensity is superposed and enhanced in the normal direction of the plane where the first metal branch is located, superposed and offset in the direction horizontally parallel to the plane where the first metal branch is located, and combined with the second metal branch group to form an array effect, so that the gain of the vehicle-mounted antenna in the vertical plane, namely the horizontal plane, of the plane where the first metal branch and the second metal branch are located is compressed and enhanced, the gain distribution in the normal direction of the plane where the metal branches are located is optimized, and the gain in the front and back ranges of the plane where the metal branches are located is increased relative to the gain in the left and right ranges.

Drawings

Fig. 1 is a schematic diagram of a vehicle-mounted antenna structure according to an example of the present invention.

Fig. 2 is a schematic structural diagram of a vehicle-mounted antenna according to an example of the present invention, wherein the structure of the first metal branch group is mainly illustrated.

Fig. 3 is a schematic diagram of a vehicle-mounted antenna according to another example of the present invention.

Fig. 4 is a schematic structural diagram illustrating an example of the first metal branch group in the vehicle-mounted antenna according to the present invention.

Fig. 5 is a partial structural diagram of a vehicle-mounted antenna according to another example of the present invention.

Fig. 6 is a schematic structural view showing a vehicle-mounted antenna according to still another example of the present invention.

Fig. 7 is a return loss diagram of a single V2X antenna according to an embodiment of the invention.

Fig. 8 shows the efficiency of a single V2X antenna and a monopole antenna (monopole) according to an embodiment of the invention.

Fig. 9a shows a schematic view of a spherical coordinate system.

Fig. 9 is a graph showing the relationship between phi angle and the front and the rear of the vehicle in a spherical coordinate system.

Fig. 10 to 12 show the directional diagrams and the average gain of the vertical polarized wave of the single V2X antenna when the single V2X antenna takes theta of 80deg,90deg and 100deg respectively along the theta direction in the first embodiment of the present invention.

Fig. 13 to 15 are direction diagrams and average gains of vertical polarized waves of a monopole antenna (monopole) when the monopole antenna (monopole) takes theta of 80deg,90deg and 100deg respectively along the theta direction according to an embodiment of the present invention.

Fig. 16 is a schematic structural diagram of an automotive shark fin antenna according to a second embodiment of the invention.

FIG. 17 is a graph showing the efficiency of the V2X antenna in the shark fin antenna in an automobile according to the second embodiment of the invention.

Fig. 18 to 20 show the directional diagram and the average gain of the vertical polarized wave of the V2X antenna when the theta of the V2X antenna in the shark fin antenna for an automobile according to the second embodiment of the present invention is 80deg,90deg and 100deg, respectively.

Fig. 21 is a schematic structural diagram of a highly integrated shark fin antenna for a vehicle according to a third embodiment of the invention.

FIG. 22 is a graph showing the radiation efficiency of the V2X/5G1 full-band antenna in the highly integrated shark fin antenna for a vehicle according to the third embodiment of the present invention.

Fig. 23 shows a directional diagram and an average gain of vertical polarized waves of the V2X antenna when the theta direction of the V2X antenna is 80deg,90deg, and 100deg, respectively, in the V2X/5G1 full-band antenna according to the third embodiment of the present invention.

Fig. 24 shows a direction diagram and an average gain of vertical polarized waves of the V2X antenna when the V2X antenna and the 5G1 full-band antenna are separately timed in the third embodiment of the present invention, and a direction diagram and an average gain of vertical polarized waves of the V2X antenna when the V2X antenna respectively takes theta as 80deg,90deg and 100deg along the theta direction (normal theta), and a direction diagram and an average gain of vertical polarized waves of the V2X antenna when the V2X antenna respectively takes theta as 80deg,90deg and 100deg along the theta direction (patent theta) in the V2X/5G1 full-band antenna in the third embodiment of the present invention.

Fig. 25 is a graph showing the linear average gain of the V2X antenna (antenna design) in the V2X/5G1 full-band antenna according to the third embodiment of the present invention, compared with the linear average gain of the V2X antenna (normal design) when the V2X antenna and the 5G1 full-band antenna are separately configured.

Fig. 26 is a view showing the installation position of the single V2X antenna in the vehicle according to the fourth embodiment of the present invention.

Fig. 27 is a view showing a manner of mounting the single V2X antenna in the vehicle according to the fourth embodiment of the present invention.

Fig. 28 is a return loss diagram of the single V2X antenna according to the fourth embodiment of the present invention.

Fig. 29 is a graph showing the efficiency of the single V2X antenna according to the fourth embodiment of the present invention.

Fig. 30 to 32 show a direction diagram and an average gain of a vertical polarized wave of a single V2X antenna when the single V2X antenna (i.e., the antenna design) takes theta of 80deg,90deg and 100deg respectively along the theta direction, and a direction diagram and an average gain of a vertical polarized wave of a dipole antenna when the dipole antenna (i.e., the dipole) takes theta of 80deg,90deg and 100deg respectively along the theta direction.

Fig. 33 is a graph showing the omnidirectional average gain of a single V2X antenna (i.e., a antenna design) and a dipole antenna (dipole) at theta 80deg,90deg and 100deg according to the fourth embodiment of the present invention.

Fig. 34 shows an average gain diagram of a single V2X antenna (i.e., a antenna design) and a dipole antenna (dipole) in the tail direction (i.e., phi is 30 deg. to 150deg) when theta is 80 deg., 90 deg., and 100 deg. in the fourth embodiment of the present invention.

Description of the element reference numerals

10 reference ground metal plate

11 first metal sheet

12 second metal sheet

13 feeding point

14 first metal branch group

140 first metal branch

141 first side

142 second side

15 second metal branch group

150 second metal branch

151 third side

152 fourth side

16 bend line

17 first capacitance element

18 zigzag coupling structure

19 third metal branch

20 fourth metal branch

21 third inductive element

22 metallic structure

23 Metal Via

24 medium

25 casing

26V 2X antenna

27 FM antenna

285G antenna

29V 2X/5G1 full-frequency antenna

30 GNSS antenna

31 MIMO antenna

325G 2 full-frequency antenna

33 SDARS antenna

34 front end V2X antenna

35 vehicle tail

36 position of rearview mirror in vehicle

37 second inductive element

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.

Please refer to fig. 1 to 34. It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the drawings only show the components related to the present invention rather than being drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of each component in actual implementation may be changed according to actual needs, and the layout of the components may be more complicated.

As shown in fig. 1 to 3, the present invention provides a vehicle-mounted antenna, including:

a reference ground metal plate 10;

a first metal sheet 11 and a second metal sheet 12 disposed above the reference ground metal plate 10 and arranged in parallel to each other; wherein, one end of the first metal sheet 11 is electrically connected with a feeding point 13, and one end of the second metal sheet 12 is electrically connected with the reference ground metal plate 10;

first metal branch groups 14 and second metal branch groups 15 are arranged at intervals in the vertical direction of the first metal sheet 11 and the second metal sheet 12;

as shown in fig. 2, the first metal branch group 14 is disposed below (where below refers to below the first metal sheet 11 and the second metal sheet 12), and includes: two identical first metal branches 140 distributed in a mirror image manner on two sides of the first metal sheet 11 and the second metal sheet 12; the first metal branch 140 includes at least two first sides 141 arranged in parallel relatively and at least two second sides 142 respectively connecting two ends of the at least two first sides 141; one of the first sides 141 has a disconnection point at a middle position thereof, one end a of the disconnection point is electrically connected to the first metal sheet 11, the other end B of the disconnection point is electrically connected to the second metal sheet 12, and the first metal branches 140 are distributed vertically symmetrically with respect to the electrical connection points with the first metal sheet 11 and the second metal sheet 12 (here, the first metal branches 140 are located at the same height with respect to the electrical connection points with the first metal sheet 11 and the second metal sheet 12);

as shown in fig. 1 and 3, the second metal branch group 15 is disposed above (where above refers to above the first metal sheet 11 and the second metal sheet 12), and includes: two identical second metal branches 150 distributed on two sides of the first metal sheet 11 and the second metal sheet 12 in a mirror image manner; the second metal branch 150 comprises at least one third side 151; one of the third sides 151 has a disconnection point at a middle position thereof, one end C of the disconnection point is electrically connected to the first metal sheet 11, the other end D is electrically connected to the second metal sheet 12, and the second metal branches 150 are distributed vertically symmetrically with respect to the electrical connection points with the first metal sheet 11 and the second metal sheet 12 (here, the second metal branches 150 are located at the same height with respect to the electrical connection points with the first metal sheet 11 and the second metal sheet 12).

According to the vehicle-mounted antenna, the first metal sheet 11 and the second metal sheet 12 are arranged as the feeder lines, the feeder lines feed energy to the two first metal branches 140, each first metal branch 140 is in a closed ring shape, the plurality of first sides 141 are respectively connected through the plurality of second sides 142, and each first metal branch 140 is equivalent to a dipole array formed by arranging the plurality of dipoles in parallel; when the distance between two adjacent dipoles is kept at a proper distance, the radiation intensity of the antenna is superposed and enhanced (e.g. in the positive and negative u-axis directions in fig. 1) in the normal direction of the plane (e.g. the vOw plane in fig. 1) where the first metal branch 140 is located, and is offset in the positive and negative v-axis directions in the plane where the first metal branch 140 is located, and in combination with the second metal branch group 15, the arrangement in the vertical direction also forms an array effect, so that the gain of the radiation intensity of the antenna in the vertical plane (e.g. the uOv plane in fig. 1) of the plane (e.g. vOw in fig. 1) where the first metal branch 140 and the second metal branch 150 are located is further enhanced in a "compression". For the V2X antenna in the vehicle-mounted wireless communication system, the general communication requirement is that the directional diagram has the horizontal plane omnidirectionality, and the front and back gain requirement (the vehicle traveling direction is the front) of the general directional diagram is larger than the left and right gains of the vehicle, the vehicle-mounted antenna can be excellently applied to the V2X antenna in the vehicle-mounted wireless communication system.

As shown in fig. 1, for example, the extending direction of the first edge 141 coincides with the extending direction of the first metal piece 11 and the second metal piece 12; the extending direction of the third side 151 is the same as the extending direction of the first metal piece 11 and the second metal piece 12. That is, the first side 141 and the third side 151 are both disposed parallel to the first metal piece 11 and the second metal piece 12.

Since the second side 142 serves to connect the adjacent first sides 141, the shape of the second side 142 is not strictly limited as long as the adjacent first sides 141 can be connected.

As shown in fig. 1, for example, a vertical distance between the first metal branch group 14 and the second metal branch group 15 is 0.5 λ -1.2 λ, λ is a medium wavelength of an operating frequency of the vehicle-mounted antenna in the presence of a medium 24, and the vertical distance refers to a distance between an electrical connection point of the first metal branch group 14 and the first metal sheet 11 and the second metal sheet 12 and an electrical connection point of the second metal branch group 15 and the first metal sheet 11 and the second metal sheet 12.

As shown in fig. 1 and 3, for example, the first metal piece 11 and the second metal piece 12 between the first metal branch group 14 and the second metal branch group 15 are provided with a bent line 16 having the same shape or a first inductance element (not shown) having the same size.

As shown in fig. 5 and 6, as an example, a disconnection point is disposed on the second metal sheet 12, and the disconnection point is disposed below an electrical connection point between the first metal branch group 14 and the first metal sheet 11 and the second metal sheet 12; and two ends of the disconnection point are connected into a first capacitive element 17 (shown in fig. 6) or a second inductive element 37 (shown in fig. 2) or a parallel connection structure or a saw-tooth coupling structure 18 (shown in fig. 5) of the first capacitive element 17 and the second inductive element 37. When the first capacitor element 17 or the parallel structure of the first capacitor element 17 and the second inductor element 37 is connected, the vehicle-mounted antenna can be isolated from the low-frequency band of other antennas such as 5G antennas beside the vehicle-mounted antenna under the condition that the vehicle-mounted antenna is not multiplexed as a V2X antenna, so that the influence of the vehicle-mounted antenna on the low frequency of the nearby antenna is reduced; when the first capacitive element 17 or the saw-tooth coupling structure 18 is connected, the low-frequency performance of the 5G antenna can be improved under the condition that the vehicle-mounted antenna is multiplexed with the 5G antenna as a V2X antenna.

As an example, the vehicle-mounted antenna further includes a third metal branch 19 electrically connected to the reference ground metal plate 10, where the third metal branch 19 is disposed near the first metal sheet 11 and generates a coupling effect with the first metal sheet 11. The third metal branch 19 is provided, so that the intermediate frequency performance of the 5G antenna can be improved under the condition that the vehicle-mounted antenna is multiplexed with the 5G antenna as a V2X antenna.

As shown in fig. 6, as another example, the vehicle-mounted antenna further includes a third metal branch 19 electrically connected to the reference ground metal plate 10; one end of the first metal sheet 11 is electrically connected to the feeding point 13 through a fourth metal branch 20, and the third metal branch 19 and the fourth metal branch 20 generate a coupling effect. The third metal branch 19 and the fourth metal branch 20 are provided, so that the intermediate frequency performance of the 5G antenna can be improved under the condition that the vehicle-mounted antenna is used as a V2X antenna and is multiplexed with the 5G antenna.

As shown in fig. 6, as an example, a third inductance element 21 is connected in series on the first metal sheet 11 under the electrical connection point of the first metal branch 140 and the first metal sheet 11. The third inductance element 21 is provided to improve the if performance of the 5G antenna in the case where the vehicle-mounted antenna is multiplexed with the 5G antenna as the V2X antenna.

The other end of the first metal sheet 11 and/or the second metal sheet 12 is electrically connected to a section of metal structure 22, and an included angle between the metal structure 22 and the vertical direction of the extending direction of the first metal sheet 11 and/or the second metal sheet 12 is-30 to-30 degrees. As shown in fig. 6, as an example, the other end of the first metal sheet 11 is electrically connected to a metal structure 22, and the metal structure 22 is perpendicular to the extending direction (e.g., the Ow direction in fig. 1) of the first metal sheet 11. The provision of the metal structure 22 can improve the low-frequency performance of the 5G antenna in the case where the vehicle-mounted antenna is multiplexed with the 5G antenna as a V2X antenna.

It should be noted here that, when the vehicle-mounted antenna of the present invention is multiplexed, a duplexer needs to be connected to the feeding point 13, so as to implement splitting of different frequency signals.

As shown in fig. 3, as an example, the medium of the vehicle antenna may be made of a conventional insulating material. PCB dielectric materials are generally preferred in actual production.

The first metal branch 140 includes at least two first sides 141. For example, as shown in fig. 3, two first sides 141 and two second sides 142 respectively connecting two ends of the two first sides 141 are provided; as shown in fig. 4, the first metal branch 140 includes three first sides 141 arranged in parallel and four second sides 142 respectively connecting two ends of the three first sides 141. Preferably, the first metal branch 140 has two first sides 141 and two second sides 142. However, more than two first sides 141 may be provided according to actual needs.

As shown in fig. 3, by way of example, the second metal branch 150 includes one third side 151 in consideration of a space size limit of the vehicle-mounted antenna provided in the vehicle. Preferably, as shown in fig. 1, when the space provided in the vehicle is large, the second metal branch 150 may also include two third edges 151 and two fourth edges 152, the two third edges 151 are relatively parallel to each other, the two fourth edges 152 are respectively connected to two ends of the two third edges 151, and most preferably, the extending direction of the two third edges 151 is the same as the extending direction of the first metal sheet 11 and the second metal sheet 12.

The vehicle-mounted antenna of the present invention will be described in detail with reference to the specific drawings and the corresponding embodiments, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The single V2X antenna is designed by using the vehicle-mounted antenna provided by the invention.

The structure of the single V2X antenna can be seen in fig. 3: set up this monomer V2X antenna on height 47mm, width 21mm, thickness are 1 mm's PCB board medium 24, and this monomer V2X antenna sets up on the first layer and the second layer of PCB board, specifically includes:

a first metal sheet 11 and a second metal sheet 12 disposed above the reference ground metal plate 10 and arranged in parallel to each other; wherein, one end of the first metal sheet 11 is electrically connected with a feeding point 13, and one end of the second metal sheet 12 is electrically connected with the reference ground metal plate 10;

first metal branch groups 14 and second metal branch groups 15 are arranged at intervals in the vertical direction of the first metal sheet 11 and the second metal sheet 12;

as shown in fig. 2, the first metal branch group 14 is disposed below the first metal sheet 11 and the second metal sheet 12, and includes: two identical first metal branches 140 distributed in a mirror image manner on two sides of the first metal sheet 11 and the second metal sheet 12; the first metal branch 140 includes two first sides 141 arranged in parallel relatively and two second sides 142 respectively connecting two ends of the two first sides 141; one of the first edges 141 has a disconnection point at its middle position, one end a of the disconnection point is electrically connected to the first metal sheet 11, the other end B is electrically connected to the second metal sheet 12, and the first metal branches 140 are vertically and symmetrically distributed about the electrical connection points with the first metal sheet 11 and the second metal sheet 12; the length of the first side 141 is 16 mm; the first metal branch 140 is in a rectangular ring shape, and the rectangular ring shape is electrically connected with the two layer parts on the first layer and the second layer of the PCB through a metal via 23 (as shown in fig. 3);

the second metal branch group 15 is disposed above the first metal sheet 11 and the second metal sheet 12, the second metal branch group 15 is located 20mm above the first metal branch group 14, and the 20mm means: the distance between the electrical connection points of the first metal branch group 14 and the first metal sheet 11 and the second metal sheet 12 and the electrical connection points of the second metal branch group 15 and the first metal sheet 11 and the second metal sheet 12 includes: two identical second metal branches 150 distributed on two sides of the first metal sheet 11 and the second metal sheet 12 in a mirror image manner; the second metal branch 150 includes a third side 151; a break point is arranged at the middle position of the third side 151, one end C of the break point is electrically connected to the first metal sheet 11, the other end D of the break point is electrically connected to the second metal sheet 12, and the second metal branches 150 are distributed up and down symmetrically about the electrical connection points with the first metal sheet 11 and the second metal sheet 12 to form a dipole structure distributed left and right;

the first metal sheet 11 and the second metal sheet 12 between the first metal branch group 14 and the second metal branch group 15 are provided with bending lines 16 with the same shape, so that the phase difference of the upper and lower groups of antennas is about one period under the limitation of height, and the effect of an array antenna is formed, so that the directional diagram of the single V2X antenna is flattened, and the effect of enhancing the gain in the horizontal and omnidirectional directions is achieved.

An actual model was made according to the above structure and tested on a 60cm disc to simulate the scenario when placed on top of a car. Meanwhile, a common monopole antenna is manufactured, and the performances of the monopole antenna and the monopole antenna are compared. The s-parameter (return loss) of the single V2X antenna is shown in fig. 7. The efficiency of the single V2X antenna band and monopole antenna tested in the dark room is shown in fig. 8. The relationship between Phi angle and vehicle Front-Rear is shown in fig. 9, where Phi is 30deg-150deg in the Rear direction (real zone), Phi is 210deg-330deg in the Front direction (Front zone), and 150deg-210deg and 330deg-30deg in the side direction (side zone). Fig. 10 to 12 show the directional diagrams of the vertical polarized wave of the single V2X antenna and the average gain at three elevation angles (theta) of 2.27dBi, -0.10dBi, -4.11dBi in the case of theta being 80deg,90deg and 100 deg. For comparison, FIGS. 13-15 show the monopole antenna pattern and average gain at the same theta angle, which in turn is 1.10dBi, -3.18dBi, and-7.51 dBi. As can be seen from the comparison, the performance of the single-cell V2X antenna of the present embodiment is more advantageous than that of a monopole antenna when the elevation angle (theta) is larger, and as can be seen from the figure, the radiation intensity of the directional pattern of the single-cell V2X antenna of the present embodiment is larger in the direction of the vehicle head and tail region than in the direction of the vehicle both sides region, and the gain in the vehicle head and tail region is further increased.

Example 2

By using the single V2X antenna in example 1, this embodiment designs an automotive shark fin antenna including the functions of the V2X antenna, the 5G antenna and the FM antenna in example 1. The composition distribution is as shown in fig. 16, and a V2X antenna 26, an FM antenna 27 and a 5G antenna 28 are arranged in sequence from the tail of the shark fin.

The darkroom test data for the above described actual model is as follows. The antenna efficiency of V2X is shown in FIG. 17, the elevation angle theta is 80deg when placed in an automotive shark fin antenna, and the directivity patterns and average gain of 90deg and 100deg are shown in FIGS. 18-20. As can be seen from fig. 18 to 20, the presence of the FM antenna 27 and the 5G antenna 28 has a slight influence on the directional pattern of the V2X antenna 26, and generates a wave-like intensity change, but the average gain is reduced by about 0.5dBi compared with that of the single V2X antenna of example 1, and the directional pattern radiation intensity is still greater in the direction of the head and tail regions of the vehicle than in the direction of the two side regions of the vehicle, which is still more advantageous than the monopole antenna of example 1.

Example 3

In this embodiment, through the antenna multiplexing design, the integrated design of the V2X antenna and the 5G antenna is realized, which is specifically as follows:

as shown in fig. 21, a highly integrated shark fin antenna including 2 × 5G (full band) antenna, 2 × 5G (mimo) antenna, 2 × V2X antenna, 1 × GNSS antenna, and 1 × SDARS antenna was designed. This high integration shark fin antenna can place on the top platform of car etc. adopts the radius to be 260mm as reference ground metal sheet 10 during this embodiment emulation, and the overall arrangement of each antenna is followed the shark fin afterbody and is in proper order: the vehicle-mounted antenna comprises a V2X/5G1 full-frequency antenna (multiplexing) 29, a GNSS antenna 30, 2 MIMO antennas 31, a 5G2 full-frequency antenna 32, an SDARS antenna 33, and a front-end V2X antenna 34, wherein the V2X/5G1 full-frequency antenna (multiplexing) 29 is designed by using the structure of the vehicle-mounted antenna of the present invention, and other antennas are designed by using a more traditional design, for example, the GNSS antenna uses a ceramic patch stacked structure to implement a dual-frequency function, etc., and the description thereof is not specifically provided.

The structure of the multiplexed V2X/5G1 full-band antenna 29 can be seen in fig. 6: in the design, the dielectric 24 is a PCB board with a height of 58mm, and the used material is a high-frequency low-loss Rogers substrate. The structure is that the distance between the first metal branch group 14 and the second metal branch group 15 in the single V2X antenna of the embodiment 1 is changed from 20mm to 25mm, and the following design is added on the basis of the embodiment 1: a disconnection point is arranged at the bottom of the second metal sheet 12, and a first capacitance element 17 with the value of 0.5pF is connected to the disconnection point; a fourth metal branch 20 is arranged at the bottom end of the first metal sheet 11, and a third inductance element 21 with an inductance value of 1nH is connected in series between the first metal sheet 11 and the fourth metal branch 20; and a metal structure 22 with the length of 11mm is connected to the top of the first metal sheet 11; and a third metal branch 19 is arranged near the fourth metal branch 20 and is coupled with the fourth metal branch 20, and the lower end of the third metal branch 19 is electrically connected with the reference ground metal plate 10. The third inductance element 21, the third metal branch 19 and the fourth metal branch 20 improve the medium-frequency performance of the 5G1 full-frequency antenna together; the metal structure 22 improves the low frequency performance of the 5G1 full frequency antenna.

The simulation results for this design are as follows: the radiation efficiency of the multiplexed 5G1 full-band antenna and the V2X antenna is shown in fig. 22, and the efficiency of the 5G1 full-band antenna is above-4 dB in the low frequency band of 698M-960M, and above-4 dB in the 1700M-2000M, 3300-5000M and high frequency band without a matching circuit; the efficiency of V2X was-0.8 dB. The cross-sectional views of the multiplexed 5G1 full-band antenna and V2X antenna, in which the theta of the V2X antenna is 80deg,90deg and 100deg, are shown in fig. 23, and the lower right corner shows the corresponding relationship between the azimuth angle of the directional pattern and the antenna position, it can be seen that the antenna gain fluctuates in the horizontal plane, but the antenna gain maintains high uniformity (low out-of-roundness).

In order to compare the superiority of the present invention in V2X performance, a conventional design in which the V2X antenna is separated from the 5G full-band antenna is also designed, and the V2X antenna is located at the front side of the 5G full-band antenna, and its performance is simulated to compare with the performance of the 5G1 full-band antenna multiplexed in this embodiment and the V2X antenna in the V2X antenna, as shown in fig. 24. As can be seen from comparison with fig. 24, in the high-integration antenna system, the antenna 5G near the antenna has a large influence on the antenna pattern of V2X, the gain fluctuates sharply and even a null point (around 150deg) appears, and the communication stability of the antenna V2X is reduced. The LAG (linear average gain) performance of the V2X antenna and the conventional V2X antenna in the 5G1 full-band antenna and the V2X antenna multiplexed in the embodiment is as shown in fig. 25, and it can be seen from the figure that the V2X antenna in the 5G1 full-band antenna and the V2X antenna multiplexed in the embodiment is far better than the conventional V2X antenna design, and has an advantage of 5dB when theta is 100 deg.

Example 4

The antenna design in this embodiment is the same as that in embodiment 1, and all are single V2X antennas. The simulation of the embodiment verifies the performance of the single V2X antenna when the single V2X antenna is installed at the position of the interior rearview mirror of the whole vehicle. The mounting position is as shown in fig. 26, and is different from embodiment 1 in that it is inverted mounting as shown in fig. 26.

The simulated return loss and efficiency are shown in fig. 28 and 29. The directional diagram and average gain when the whole vehicle simulated theta is 80deg,90deg and 100deg are shown in fig. 30 to 32, wherein the phi angle and vehicle end-to-end relation refers to fig. 12, and the dipole antenna performance when arranged at the same position is also simulated for comparison, as shown by the dotted lines in fig. 30 to 32. As can be seen from the figure, the gain of the dipole antenna and the design of the present embodiment have a strong attenuation at the tail of the vehicle, which in practice greatly affects the communication between the front and rear vehicles. Fig. 33 and 34 show the omni-directional average gain map (as shown in fig. 33) and the tail-direction (phi ═ 30deg-150deg) average gain map (as shown in fig. 34) of the single V2X antenna and the dipole antenna at the above 3 theta angles in this embodiment, and the above description is further verified from the data.

In summary, the present invention provides a vehicle-mounted antenna, in which a first metal sheet and a second metal sheet are arranged as a feeder line, the feeder line feeds energy to two first metal branches, each first metal branch is in a closed loop shape, and a plurality of first sides are respectively connected by a plurality of second sides, so that each first metal branch is equivalent to a dipole array in which a plurality of dipoles are arranged side by side; when the distance between two adjacent dipoles keeps a proper distance, the radiation intensity of the antenna is superposed and enhanced in the direction normal to the plane where the first metal branch is located, and superposed and offset in the direction horizontally parallel to the plane where the first metal branch is located, and in addition, the second metal branch group is combined to form an array effect. Finally, the gain of the vehicle-mounted antenna on a plane perpendicular to the plane where the first metal branch and the second metal branch are located is compressed and enhanced, meanwhile, the gain distribution of the normal direction of the plane where the metal branches are located is optimized, and the gain in the front-back range of the plane where the metal branches are located is larger than the gain in the left-right range. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims (14)

1. A vehicle antenna, characterized in that it comprises:

a reference ground metal plate;

the first metal sheet and the second metal sheet are arranged above the reference ground metal plate and are arranged in parallel relatively; one end of the first metal sheet is electrically connected with a feed point, and one end of the second metal sheet is electrically connected with the reference ground metal plate;

a first metal branch group and a second metal branch group are arranged at intervals along the up-down direction of the first metal sheet and the second metal sheet;

the first metal branch group is arranged below and comprises: two first metal branches which are identical and distributed on two sides of the first metal sheet and the second metal sheet in a mirror image manner; the first metal branch knot comprises at least two first edges which are arranged in parallel relatively and at least two second edges which are respectively connected with two ends of the at least two first edges; one first edge is provided with a disconnection point at the middle position, one end of the disconnection point is electrically connected to the first metal sheet, the other end of the disconnection point is electrically connected to the second metal sheet, and the first metal branches are vertically and symmetrically distributed relative to the electrical connection points with the first metal sheet and the second metal sheet;

the second metal branch group is arranged above and comprises: two identical second metal branches distributed on two sides of the first metal sheet and the second metal sheet in a mirror image manner; the second metal branch segment comprises at least one third edge; and a disconnection point is arranged at the middle position of the third edge, one end of the disconnection point is electrically connected to the first metal sheet, the other end of the disconnection point is electrically connected to the second metal sheet, and the second metal branches are vertically and symmetrically distributed relative to the electrical connection points with the first metal sheet and the second metal sheet.

2. The vehicle antenna of claim 1, wherein: the extending direction of the first edge is consistent with the extending direction of the first metal sheet and the second metal sheet; the extending direction of the third side is consistent with the extending direction of the first metal sheet and the second metal sheet.

3. Vehicle antenna according to claim 1, characterized in that: the vertical distance between the first metal branch group and the second metal branch group is 0.5 lambda-1.2 lambda, lambda is the medium wavelength of the working frequency of the vehicle-mounted antenna, and the distance refers to the distance between the electric connection points of the first metal branch group and the first metal sheet and the second metal sheet and the electric connection points of the second metal branch group and the first metal sheet and the second metal sheet.

4. The vehicle antenna of claim 1, wherein: the first metal sheet and the second metal sheet between the first metal branch group and the second metal branch group are provided with bent lines in the same shape or first inductance elements in the same size.

5. The vehicle antenna of claim 1, wherein: a disconnection point is arranged on the second metal sheet and is arranged below the electric connection point of the first metal branch knot group, the first metal sheet and the second metal sheet; and two ends of the disconnection point are connected into a first capacitance element or a second inductance element or a parallel connection structure or a saw-tooth coupling structure of the first capacitance element and the second inductance element.

6. The vehicle antenna of claim 1, wherein: the vehicle-mounted antenna also comprises a third metal branch electrically connected with the reference ground metal plate, wherein the third metal branch is arranged near the first metal sheet and generates a coupling effect with the first metal sheet.

7. The vehicle antenna of claim 1, wherein: the vehicle-mounted antenna also comprises a third metal branch electrically connected with the reference ground metal plate; one end of the first metal sheet is electrically connected with the feed point through a fourth metal branch, and the third metal branch and the fourth metal branch generate a coupling effect.

8. The vehicle antenna of claim 1, wherein: and a third inductance element is connected in series on the first metal sheet below the electric connection point of the first metal branch and the first metal sheet.

9. Vehicle antenna according to claim 1, characterized in that: the other end of the first metal sheet and/or the second metal sheet is electrically connected with a section of metal structure, and the included angle between the metal structure and the first metal sheet and/or the second metal sheet in the vertical direction of the extending direction is-30 degrees.

10. The vehicle antenna of claim 1, wherein: when the vehicle-mounted antenna is multiplexed, a duplexer is connected to the feed point to realize shunting of signals with different frequencies.

11. The vehicle antenna of claim 1, wherein: the vehicle-mounted antenna is arranged on the PCB dielectric material, and the other first edge without the disconnection point is connected through the metal through hole.

12. The vehicle antenna of claim 1, wherein: the first metal branch knot comprises three first edges which are arranged in parallel relatively and four second edges which are respectively connected with two ends of the three first edges.

13. The vehicle antenna of claim 1, wherein: the second metal branch segment includes one of the third edges.

14. The vehicle antenna of claim 1, wherein: the second metal branch knot comprises two third edges and two fourth edges, the third edges are arranged in parallel relatively, the extending direction of the third edges is consistent with the extending direction of the first metal sheet and the extending direction of the second metal sheet, and the fourth edges are connected with the two ends of the third edges respectively.

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