Vehicle-mounted antenna

Abstract

The utility model provides a vehicle-mounted antenna, which comprises at least two antenna arrays vertically arranged on a high-frequency printed circuit board; the phase shift feed network is fixed on the high-frequency printed circuit board and is connected with each antenna array; the first metal frame is arranged on the periphery of the high-frequency printed circuit board and surrounds the at least two antenna arrays, the first metal frame comprises a plurality of grid bars which are vertically arranged at intervals, and the surfaces, facing the antenna arrays, of the grid bars form signal reflecting surfaces; the first metal frame comprises a first frame surface and a second frame surface, and the area of a signal reflecting surface of the first frame surface is larger than that of a signal reflecting surface of the second frame surface; a first preset angle is formed between the first frame surface and at least one antenna array, a second preset angle is formed between the second frame surface and the corresponding antenna array, and the second preset angle is different from the first preset angle. The antenna can adjust the gain characteristic of the elevation section of the antenna, and achieves the effect of improving the gain of the low elevation section of the antenna.

Description

Technical Field

[0001] The utility model relates to the technical field of antennas, in particular to a vehicle-mounted antenna. Background Art

[0002] In the field of satellite communications, to maximize the transmission and reception of satellite signals, antennas must not only possess wide-beam circular polarization coverage but also high radiation gain at low elevation angles. For in-vehicle communications using satellite antennas, coverage of the upper hemisphere, particularly within the 0-70 degree elevation angle range, is particularly important.

[0003] However, existing vehicle-mounted antennas can only achieve good gain characteristics higher than 0dBi at a 60-degree elevation angle, but cannot achieve radiation requirements higher than 0dBi gain at slightly higher low elevation angles (such as greater than or equal to 60 degrees and less than or equal to 80 degrees). Utility Model Content

[0004] The technical solution of the utility model aims to provide a vehicle-mounted antenna for improving the gain characteristics of the antenna at low elevation angles.

[0005] One embodiment of the present invention provides a vehicle-mounted antenna, comprising:

[0006] At least two antenna elements are vertically arranged on a high-frequency printed circuit board;

[0007] A phase-shift feed network, the phase-shift feed network being fixed on the high-frequency printed circuit board and connected to each of the antenna elements;

[0008] a first metal frame, disposed on the periphery of the high-frequency printed circuit board and surrounding the at least two antenna elements, wherein the first metal frame includes a plurality of spaced and vertically arranged grid bars, wherein surfaces of the grid bars facing the antenna elements form signal reflection surfaces;

[0009] The first metal frame includes a first frame surface and a second frame surface, the area of ​​the signal reflection surface of the first frame surface is larger than the area of ​​the signal reflection surface of the second frame surface; the first frame surface is at a first preset angle with at least one of the antenna elements, and the second frame surface is at a second preset angle with the corresponding antenna element, and the second preset angle is different from the first preset angle.

[0010] Optionally, in the vehicle-mounted antenna, the at least two antenna elements include a first antenna element and a second antenna element arranged in a cross shape;

[0011] The first frame surface includes a first frame surface corresponding to the first antenna element and a second frame surface corresponding to the second antenna element; wherein the area of ​​the signal reflection surface of the first frame surface is different from the area of ​​the signal reflection surface of the second frame surface.

[0012] Optionally, the vehicle-mounted antenna, wherein the second frame surface includes a third frame surface corresponding to the first antenna element and a fourth frame surface corresponding to the second antenna element; wherein the area of ​​the signal reflection surface of the third frame surface is different from the area of ​​the signal reflection surface of the fourth frame surface.

[0013] Optionally, in the vehicle-mounted antenna, each of the antenna elements comprises:

[0014] a main body portion vertically arranged relative to the high-frequency printed circuit board;

[0015] a first extending portion extending toward both sides at one end of the main body away from the high-frequency printed circuit board, wherein the first extending portion is parallel to the high-frequency printed circuit board;

[0016] A second extending portion extends from one end of the first extending portion away from the main body portion toward the high-frequency printed circuit board, and the second extending portion is perpendicular to the high-frequency printed circuit board.

[0017] Optionally, the vehicle-mounted antenna further comprises:

[0018] A second metal frame, the second metal frame includes a plurality of metal strip groups arranged on a side of the first metal frame away from the antenna element; each of the metal strip groups includes at least one vertically arranged first metal strip, and the first metal strip belonging to a metal strip group is arranged opposite to one of the antenna elements.

[0019] Optionally, in the vehicle-mounted antenna, the second metal frame further includes at least one second metal strip located between two adjacent metal strip groups, and the height of the second metal strip is smaller than the height of the first metal strip.

[0020] Optionally, in the vehicle-mounted antenna, the second metal frame further includes a circular base plate, and the first metal strip and the second metal strip are arranged at the edge of the circular base plate, surrounding the first metal frame.

[0021] Optionally, in the vehicle-mounted antenna, the first metal frame further includes a rectangular base plate, the rectangular base plate is arranged on the circular base plate, and the plurality of bars are arranged along the edge of the circular base plate.

[0022] Optionally, the vehicle-mounted antenna, wherein the bars on the first frame surface are arranged in a one-to-one correspondence with the bars on the second frame surface, the size of the bars on the first frame surface is the same as the size of the corresponding bars on the second frame surface, but at least one of the bars on the second frame surface is provided with an opening, and the height and width of the opening are related to the center frequency wavelength of the antenna signal.

[0023] Optionally, in the vehicle-mounted antenna, a slit is provided between the first frame surface and the second frame surface, and the height of the slit is related to the center frequency wavelength of the antenna signal.

[0024] Optionally, in the vehicle-mounted antenna, the width and height of the bars and the width and height of the slits between two adjacent bars are respectively related to the center frequency wavelength of the antenna signal.

[0025] Optionally, in the vehicle-mounted antenna, the first preset angle is less than 50 degrees and greater than 40 degrees.

[0026] At least one of the above technical solutions in the specific embodiment of the utility model has the following beneficial effects:

[0027] The vehicle-mounted antenna described in the embodiment of the present utility model is provided with a first metal frame having a non-uniform signal reflection surface on the periphery of the antenna array. By making the area of ​​the signal reflection surface of the first frame surface of the first metal frame at a first preset angle to the antenna array larger than the area of ​​the signal reflection surface of the second frame surface at a second preset angle to the antenna array, the signal reflection surface area is supplemented on the first frame surface, and the gain characteristics of the antenna elevation angle section are adjusted, thereby achieving the effect of improving the gain of the antenna low elevation angle section. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a perspective schematic diagram of a vehicle-mounted antenna according to an embodiment of the present utility model;

[0029] Figure 2 This is a schematic exploded perspective view of the vehicle-mounted antenna according to an embodiment of the present utility model;

[0030] Figure 3 This is a schematic top view of the vehicle-mounted antenna according to an embodiment of the present utility model;

[0031] Figure 4 A schematic diagram illustrating the positional relationship between the antenna element and the first metal frame in the vehicle-mounted antenna according to an embodiment of the present invention;

[0032] Figure 5 is a schematic diagram of the three-dimensional structure of the first metal frame;

[0033] Figure 6 is a schematic diagram of the three-dimensional structure of the second metal frame;

[0034] Figure 7 A graph showing the standing wave ratio characteristics of the vehicle-mounted antenna according to an embodiment of the present utility model;

[0035] Figure 8 It shows the transmission frequency band pattern of the vehicle-mounted antenna according to the embodiment of the present utility model;

[0036] Figure 9 It shows the directional pattern of the vehicle-mounted antenna transmitting in the frequency band at an elevation angle of 45 degrees according to the embodiment of the present utility model;

[0037] Figure 10 It shows the directional pattern of the vehicle-mounted antenna transmitting in the frequency band at an elevation angle of 75 degrees according to the embodiment of the present utility model;

[0038] Figure 11 It represents the vertex axis ratio characteristic of the transmitting frequency band of the vehicle-mounted antenna according to the embodiment of the present utility model;

[0039] Figure 12 It shows the receiving frequency band pattern of the vehicle-mounted antenna according to the embodiment of the present utility model;

[0040] Figure 13 It shows the directional pattern of the receiving frequency band of the vehicle-mounted antenna according to the embodiment of the present utility model at an elevation angle of 45 degrees;

[0041] Figure 14 It shows the directional pattern of the vehicle-mounted antenna receiving frequency band at an elevation angle of 75 degrees according to the embodiment of the present utility model;

[0042] Figure 15 A graph showing the vertex axis ratio characteristics of the receiving frequency band of the vehicle-mounted antenna according to an embodiment of the present utility model. DETAILED DESCRIPTION

[0043] In order to make the technical problems to be solved, technical solutions and advantages of the present invention clearer, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0044] The terms "first," "second," and the like in the specification and claims of the present invention are used to distinguish similar objects, and are not used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than that illustrated or described herein, and that the objects distinguished by "first" and "second" are generally of the same type, and do not limit the number of objects. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0045] In order to improve the gain characteristics of the low-elevation-angle section of the antenna, an embodiment of the present invention provides a vehicle-mounted antenna, in which a first metal frame with a non-uniform signal reflection surface is arranged on the periphery of the antenna array. By making the area of ​​the signal reflection surface of the first frame surface of the first metal frame at a first preset angle to the antenna array larger than the area of ​​the signal reflection surface of the second frame surface at a second preset angle to the antenna array, the signal reflection surface area is supplemented on the first frame surface, and the gain characteristics of the antenna elevation section are adjusted to achieve the effect of improving the gain of the low-elevation-angle section of the antenna.

[0046] like Figure 1 and Figure 2 As shown, the vehicle-mounted antenna according to the embodiment of the present invention, in one embodiment, includes:

[0047] At least two antenna elements 100 are vertically arranged on a high-frequency printed circuit board 200;

[0048] A phase-shifted feed network 300 , which is fixed on the high-frequency printed circuit board 200 and connected to each antenna element 100 ;

[0049] The first metal frame 400 is disposed on the periphery of the high-frequency printed circuit board 200 and surrounds at least two antenna elements 100. The first metal frame 400 includes a plurality of spaced and vertically arranged grid bars 10. The surfaces of the grid bars 10 facing the antenna elements 100 serve as signal reflection surfaces.

[0050] Among them, the first metal frame 400 includes a first frame surface 410 and a second frame surface 420, and the area of ​​the signal reflection surface of the first frame surface 410 is larger than the area of ​​the signal reflection surface of the second frame surface 420; the first frame surface 410 is at a first preset angle with at least one antenna element 100, and the second frame surface 420 is at a second preset angle with the corresponding antenna element 100, and the second preset angle is different from the first preset angle.

[0051] In the vehicle-mounted antenna described in this embodiment of the utility model, a first metal frame 400, disposed around at least two antenna elements 100, forms a metal boundary for the vibrating electric field generated by the antenna elements 100. The multiple spaced-apart bars 10 provided on the first metal frame 400 form a signal reflection surface, which, by secondary excitation of the vibrating electric field generated by the antenna elements 100, obtains transmit and receive signals within a preset frequency band. In this embodiment of the utility model, the signal reflection surface area of ​​a first frame surface 410 of the first metal frame 400, which is at a first preset angle to the antenna elements 100, is greater than the signal reflection surface area of ​​a second frame surface 420 at a second preset angle to the antenna elements. This creates a structure with a non-uniform signal reflection surface, which is used to supplement the signal reflection surface area on the first frame surface 410 and adjust the gain characteristics of the antenna elevation section.

[0052] Alternatively, as Figure 1 and Figure 2 As shown, the at least two antenna elements 100 include a first antenna element 110 and a second antenna element 120 arranged in a cross pattern. Optionally, the first antenna element 110 is formed as a positive 45-degree polarized half-wave antenna element, and the second antenna element 120 is formed as a negative 45-degree polarized half-wave antenna element. In other words, the first antenna element 110 and the second antenna element 120 are arranged in a cross pattern with their phase centers overlapping.

[0053] In the embodiment of the present invention, the structure and principle of the vehicle-mounted antenna described in the embodiment of the present invention are explained by taking the antenna array 100 including the first antenna array 110 and the second antenna array 120 as an example. However, it should be noted that in some special cases, the number of antenna arrays is not limited to two.

[0054] Combine Figure 3 As shown, in this embodiment of the present invention, at least two antenna elements 100 are vertically mounted on a high-frequency printed circuit board 200, and a phase-shifted feed network 300 is disposed on the high-frequency printed circuit board 200. The phase-shifted feed network 300 is connected to the first antenna element 110 and the second antenna element 120, respectively, and is used to split the transmitted antenna signal into at least two signals with different phases and the same amplitude. These at least two signals are respectively transmitted to different antenna elements 100.

[0055] Optionally, the phase-shifted feeding network 300 includes a Wilkinson power divider, a phase shifter, and an isolation resistor that can achieve equal power division into two paths. The Wilkinson power divider is used to achieve phase delay. After obtaining the antenna signal of the feed source through the feed 201 on the high-frequency printed circuit board 200, the obtained antenna signal power is divided into two signals with equal amplitude and a phase difference of 90 degrees. One signal is transmitted to the first antenna array 110, and the other signal is transmitted to the second antenna array 120.

[0056] Optionally, in the phase-shifted feeding network 300 , the Wilkinson power divider is welded between two branch circuits respectively connected to the first antenna element 110 and the second antenna element 120 using a resistor 202 .

[0057] In one embodiment of the present utility model, optionally, Figure 1 and Figure 2 As shown, each of the antenna elements 100 includes:

[0058] A main body portion 101 vertically disposed relative to the high-frequency printed circuit board 200;

[0059] A first extension portion 102 extending toward both sides at one end of the main body portion 101 away from the high-frequency printed circuit board 200 , wherein the first extension portion 102 is parallel to the high-frequency printed circuit board 200 ;

[0060] A second extending portion 103 extends from one end of the first extending portion 102 away from the main portion 101 toward the high-frequency printed circuit board 200 . The second extending portion 103 is perpendicular to the high-frequency printed circuit board 200 .

[0061] In the embodiment of the present invention, optionally, the first antenna element 110 and the second antenna element 120 have the same shape and size.

[0062] Compared with the antenna array that is usually arranged in a "T"-shaped structure, the antenna array in the vehicle-mounted antenna described in the embodiment of the utility model is formed into an "M"-shaped structure, with both sides formed into a shape that bends downward and extends, so that compared with the antenna array with a "T"-shaped structure of the same radiation area, the radiation aperture is reduced, thereby achieving the effect of improving the gain characteristics of the antenna elevation angle section to a certain extent.

[0063] In an embodiment of the present invention, for one of the antenna elements (first antenna element 110 and / or second antenna element 120), first metal frame 400 includes a first frame surface 410 that forms a first preset angle with respect to the corresponding antenna element, and also includes a second frame surface 420 that forms a second preset angle with respect to the corresponding antenna element, wherein the signal reflection surface area of ​​first frame surface 410 is greater than the signal reflection surface area of ​​second frame surface 420. Optionally, the first preset angle is less than 50 degrees and greater than 40 degrees, and the second preset angle is any angle different from the first preset angle.

[0064] With this embodiment, the antenna element's antenna signal is secondary excited, and the signal reflection surface at a specific angle (a first preset angle) has a larger area than the signal reflection surface at other angles relative to the antenna element. This complements the signal reflection surface area at this specific angle, thereby adjusting the gain characteristics of the antenna's elevation section. Furthermore, by providing wide bars on the first frame surface, excellent electromagnetic wave reflection is achieved, while by providing narrow bars on the second frame surface, electromagnetic wave guidance is achieved. Based on the resulting first metal frame with a non-uniform signal reflection surface, the gain characteristics at a low elevation angle of 75 degrees can optionally be optimized.

[0065] Combine Figure 4 and Figure 5As shown, optionally, when the first antenna array 110 is formed as a positive 45-degree polarized half-wave antenna array and the second antenna array 120 is formed as a negative 45-degree polarized half-wave antenna array, based on the coordinate system formed by the reference, the first metal frame 400 includes a first frame surface 411 located at a coordinate of 0 degrees, a second frame surface 412 located at a coordinate of -90 degrees, a third frame surface 421 located at a coordinate of 180 degrees (or -180 degrees) and a fourth frame surface 422 located at a coordinate of 90 degrees. The first frame surface 411, the second frame surface 412, the third frame surface 421 and the fourth frame surface 422 are combined to form a tetrahedron shape, and each frame surface 411 includes a plurality of spaced and vertically arranged bars.

[0066] In the embodiment of the present utility model, Figure 4 As shown, optionally, the angle of the first frame plane 411 located at the coordinate 0 degree relative to the first antenna array 110 is 45 degrees (the first preset angle), that is, the first frame plane 411 is the first frame plane corresponding to the first antenna array 110; the angle of the second frame plane 412 located at the coordinate -90 degrees relative to the second antenna array 120 is 45 degrees (the first preset angle), that is, the second frame plane 412 is the first frame plane corresponding to the second antenna array 120.

[0067] Furthermore, the third frame plane 421, located at a coordinate of 180 degrees, is at an angle of 135 degrees relative to the first antenna element 110. This means that the third frame plane 421 is the second frame plane corresponding to the first antenna element 110, and the signal reflection surface area of ​​the first frame plane 411 is larger than the signal reflection surface area of ​​the third frame plane 421. The fourth frame plane 422, located at a coordinate of 90 degrees, is at an angle of 135 degrees relative to the second antenna element 120. This means that the fourth frame plane 422 is the second frame plane corresponding to the second antenna element 120, and the signal reflection surface area of ​​the second frame plane 412 is larger than the signal reflection surface area of ​​the fourth frame plane 422.

[0068] In an embodiment of the present invention, the first frame surface 410 includes a first frame surface 411 corresponding to the first antenna array 110 (i.e., at a first preset angle), and a second frame surface 412 corresponding to the second antenna array 120 (i.e., at a second preset angle); optionally, the area of ​​the signal reflection surface of the first frame surface 411 is different from the area of ​​the signal reflection surface of the second frame surface 412.

[0069] The second frame surface 420 includes a third frame surface 421 corresponding to the first antenna array 110 (i.e., at a second preset angle), and a fourth frame surface 422 corresponding to the second antenna array 120 (i.e., at a second preset angle); optionally, the area of ​​the signal reflection surface of the third frame surface 421 is different from the area of ​​the signal reflection surface of the fourth frame surface 422.

[0070] See Figure 5 As shown, in the embodiment of the present invention, the first frame surface 411 , the second frame surface 412 , the third frame surface 421 and the fourth frame surface 422 respectively include a plurality of spaced and vertically arranged bars 10 , and strip-shaped slits are formed between adjacent bars 10 .

[0071] In one embodiment, optionally, the number of bars 10 provided on the first frame surface 411 and the second frame surface 412 is smaller than the number of bars 10 provided on the third frame surface 421 and the fourth frame surface 422, and the width of the bars 10 provided on the first frame surface 411 and the second frame surface 412 is larger than the width of the bars 10 provided on the third frame surface 421 and the fourth frame surface 422, so that the area of ​​the signal reflection surface of the first frame surface 411 and the second frame surface 412 is larger than the area of ​​the signal reflection surface of the third frame surface 421 and the fourth frame surface 422. In this way, by adopting this setting structure, a certain fence area is supplemented on the 0-degree plane and the -90-degree plane of the antenna array, thereby achieving the effect of optimizing the gain characteristics of the antenna elevation section.

[0072] In the embodiment of the present utility model, optionally, refer to Figure 5 As shown, the bars 10 on the first frame surface 411 are arranged in a one-to-one correspondence with the bars 10 on the second frame surface 412. The size of the bars 10 on the first frame surface 411 is the same as the size of the corresponding bars 10 on the second frame surface 412, but at least one bar 10 on the second frame surface 412 is provided with an opening 20, and the height and width of the opening 20 are related to the center frequency wavelength of the antenna signal.

[0073] In addition, in the first frame surface 411, the second frame surface 412, the third frame surface 421 and the fourth frame surface 422 connected in sequence by the first metal frame 400, optionally, a slit 30 is provided between the second frame surface 412 (first frame surface) and the third frame surface 421 (second frame surface), and the height of the slit 30 is related to the center frequency wavelength of the antenna signal.

[0074] With this embodiment, by providing an opening 20 on the bars 10 of the second frame surface 412 and providing a slit 30 between the second frame surface 412 and the third frame surface 421 , the gain of the antenna elevation section is further adjusted, thereby achieving the effect of optimizing the gain characteristics of the antenna elevation section.

[0075] Optionally, the plurality of bars 10 on the third frame surface 421 are evenly arranged, and the widths of the plurality of bars 10 are the same. The fourth frame surface 422 includes a plurality of evenly arranged bars 10 of the same width, and also includes bars 10 having widths different from those of the other bars 10. Specifically, the width of the bars 10 of the fourth frame surface 422 near the first frame surface 411 is greater than the widths of the other bars 10 on the fourth frame surface 422, so that the area of ​​the signal reflection surface of the fourth frame surface 422 is different from the area of ​​the signal reflection surface of the third frame surface 421, thereby achieving the effect of adjusting the antenna elevation angle section gain.

[0076] In an embodiment of the present invention, optionally, on the first frame surface 411, the second frame surface 412, the third frame surface 421 and the fourth frame surface 422, the width and height of the grid bars 10 and the width and width of the slits between two adjacent grid bars 10 are respectively related to the center frequency wavelength of the antenna signal.

[0077] In addition, optionally, the edge lengths and heights of the first frame surface 411 , the second frame surface 412 , the third frame surface 421 and the fourth frame surface 422 are respectively the same, and the side lengths are related to the center frequency wavelength of the antenna signal.

[0078] In one embodiment, optionally, the length of each edge of the first frame surface 411, the second frame surface 412, the third frame surface 421, and the fourth frame surface 422 is A1λ, where A1 is between 0.3 and 0.45, and optionally, A1 is 0.38; the height of the first frame surface 411, the second frame surface 412, the third frame surface 421, and the fourth frame surface 422 is A2λ, where A2 is between 0.14 and 0.2, and optionally, A2 is 0.17. λ is the center frequency wavelength of the antenna signal.

[0079] In order to achieve better gain characteristics of the antenna elevation section, on the first frame surface 411 and the second frame surface 412, the width dimension of the grid bar 10 is B1λ, B1 is between 0.08 and 0.12, optionally, B1 is 0.1; the width dimension of the slit is B2λ, B2 is between 0.02 and 0.04, optionally, B2 is 0.03.

[0080] Optionally, the heights of the slits on the first frame surface 411 , the second frame surface 412 , the third frame surface 421 and the fourth frame surface 422 are the same, such as C1λ; C1 is between 0.12 and 0.17, and optionally, C1 is 0.15.

[0081] Optionally, the height of the opening 20 on the second frame surface 412 is D1λ, where D1 is between 0.02 and 0.04, and optionally, D1 is 0.03. Optionally, the width of the opening 20 is the same as the width of the gap between adjacent bars 10.

[0082] Optionally, the height of the slit 30 provided between the second frame surface 412 and the third frame surface 421 is D2λ, and D2 is between 0.08 and 0.12. Optionally, D2 is 0.1.

[0083] In the embodiment of the present utility model, optionally, combined with Figure 1 、 Figure 2 and Figure 6 As shown, the vehicle-mounted antenna also includes:

[0084] The second metal frame 500 includes a plurality of metal strip groups 510 arranged on a side of the first metal frame 400 away from the antenna element 100; each metal strip group 510 includes at least one vertically arranged first metal strip 511, and the first metal strip 511 belonging to a metal strip group 510 is arranged opposite to an antenna element 100.

[0085] In one embodiment, optionally, the second metal frame 500 further includes at least one second metal strip 520 located between two adjacent metal strip groups 510 , and the height of the second metal strip 520 is smaller than that of the first metal strip 511 .

[0086] Optionally, the second metal frame 500 further includes a circular bottom plate 530 , and the first metal strip 511 and the second metal strip 520 are arranged at the edge of the circular bottom plate 530 around the first metal frame 400 .

[0087] In this embodiment, multiple first metal strips 511 are respectively arranged at relative positions of the first antenna element 110 and the second antenna element 120, and the multiple first metal strips 511 and the multiple second metal strips 520 with different heights are arranged around the periphery of the first antenna element 110 and the second antenna element 120 and around the edge of the circular base plate 530, so that the multiple first metal strips 511 and the multiple second metal strips 520 form an annular excitation surface for the antenna signal, which is used to achieve the effect of improving the roundness of the low elevation angle surface of the antenna.

[0088] In an embodiment of the present invention, the diameter of the circular base plate 530, the height of the first metal strip 511, and the height of the second metal strip 520 are optionally related to the center frequency wavelength of the antenna signal. Optionally, the diameter of the circular base plate 530 is E1λ, where E1 is between 0.5 and 0.62, and optionally, E1 is 0.58. The height of the first metal strip 511 is 10 times the height of the second metal strip 520. Optionally, the height of the first metal strip 511 is E2λ, where E2 is between 0.1 and 0.12, and optionally, E2 is 0.1. Optionally, the height of the second metal strip 520 is E3λ, where E3 is between 0.009 and 0.014, and optionally, E3 is 0.01.

[0089] In the embodiment of the present utility model, optionally, one embodiment thereof, as Figure 1 and Figure 2 As shown, the first metal frame 400 further includes a rectangular bottom plate 430 , which is disposed on the circular bottom plate 530 , and a plurality of bars 10 are disposed along the edge of the circular bottom plate 430 .

[0090] The vehicle-mounted antenna of the embodiment of the present utility model can optionally be: Figure 1 and Figure 2 As shown, at least two antenna elements 100 are fixed to a high-frequency printed circuit board 200 by welding. The high-frequency printed circuit board 200, on which the antenna elements 100 are mounted, is disposed within a first metal frame 400. The first metal frame 400 is fixed to the circular bottom plate 530 of the second metal frame 500 via a rectangular bottom plate 430. Optionally, the vehicle-mounted antenna also includes an antenna top cover 600 covering the antenna elements 100 and an antenna bottom cover 700 located below the second metal frame 500. The antenna bottom cover 700 is provided with protruding studs 701. The high-frequency printed circuit board 200 is secured to the corresponding studs by screws provided on its bottom surface, which penetrate the rectangular bottom plate 430 of the first metal frame 400 and the circular bottom plate 530 of the second metal frame 500. In addition, the antenna top cover 600 and the antenna bottom cover 700 are buckled together to form a receiving space, and the antenna element 100, the high-frequency printed circuit board 200, the first metal frame 400 and the second metal frame 500 are assembled and placed in the receiving space.

[0091] Optionally, a feed 201 connected to the phase-shifted feed network 300 is provided on the high-frequency printed circuit board 200, and a radio frequency line 301 connected to the feed 201 passes through a radio frequency line outlet 702 on the antenna bottom cover 700 and extends from the vehicle antenna for connecting to the feed source.

[0092] The embodiment of the present invention adopts the vehicle-mounted antenna of the above-mentioned embodiment structure, which has a wide working bandwidth and can fully cover the S band. The transmitting frequency is between 1980 and 2010 MHz, and the receiving frequency is between 2170 and 2200 MHz. It has an excellent standing wave ratio characteristic of less than 1.2 in the entire frequency band, and has an excellent peak gain of more than 4.4 dBi in the antenna frequency band, and has a half-power beamwidth of more than 125 degrees. Figure 7 and Figure 8 shown.

[0093] The vehicle-mounted antenna of the embodiment of the present invention adjusts the gain characteristics of the antenna elevation section by making the signal reflection surface area of ​​the first frame surface of the first metal frame at a first preset angle to the antenna element larger than the signal reflection surface area of ​​the second frame surface at a second preset angle to the antenna element, thereby supplementing the signal reflection surface area on the first frame surface. Figure 9As shown, the gain characteristic diagram of the vehicle-mounted antenna according to the embodiment of the utility model is shown in FIG. 1 and FIG. 2 on the elevation angle slice of the transmission frequency band a of 45 degrees. Figure 10 The gain characteristic diagram shown in the transmission frequency band b is a 75-degree elevation angle slice direction. It can be seen that the vehicle-mounted antenna using this implementation structure has an excellent gain of more than 2.7dBi at a 45-degree elevation angle slice, and even at ultra-low elevation angle slices above 75 degrees, it can still achieve an excellent gain of more than 0dBi, greatly improving the upper hemisphere range of the vehicle-mounted antenna signal transmission.

[0094] In addition, the vehicle-mounted antenna using this implementation structure can achieve a 3dB axial ratio beamwidth of more than 225 degrees in the transmit frequency band, and has an excellent axial ratio characteristic of less than 1.5dB in the axial direction. It can achieve a peak gain of more than 3.8dBi in the receive frequency band and has a half-power beamwidth of more than 140 degrees, providing a strong guarantee for the quality of the vehicle-mounted antenna receiving signals. Figure 11 and Figure 12 shown.

[0095] like Figure 13 As shown, the gain characteristic diagram of the vehicle-mounted antenna according to the embodiment of the utility model is shown in FIG. 1 and FIG. 2 on the elevation angle slice of the receiving frequency band a of 45 degrees. Figure 14 The gain characteristic diagram for the receiving frequency band b, which is a 75-degree elevation cut plane, shows that the antenna achieves an excellent gain exceeding 2.6dBi at a 45-degree elevation cut plane, and an excellent gain exceeding 0.3dBi at a low 75-degree elevation cut plane in the transmitting frequency band. This effectively improves the communication quality of satellite signals received by vehicle-mounted terminals.

[0096] In addition, the vehicle-mounted antenna using this implementation structure has a 3dB axial ratio wave width of more than 230 degrees in the receiving frequency band, and can achieve an excellent axial ratio of less than 0.7dB in the axial direction, achieving excellent circular polarization characteristics, such as Figure 15 shown.

[0097] According to the above, the vehicle-mounted antenna described in the embodiment of the present invention adjusts the gain characteristics of the antenna elevation angle section to achieve the effect of improving the gain of the antenna low elevation angle section. Even at an ultra-low elevation angle section, high gain and wide-axis ratio circular polarization characteristics can still be achieved.

[0098] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary personnel in this technical field, several improvements and modifications can be made without departing from the principles described in the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A vehicle-mounted antenna, characterized in that: include: At least two antenna elements are vertically arranged on a high-frequency printed circuit board; A phase-shift feed network, the phase-shift feed network being fixed on the high-frequency printed circuit board and connected to each of the antenna elements; a first metal frame, disposed on the periphery of the high-frequency printed circuit board and surrounding the at least two antenna elements, wherein the first metal frame includes a plurality of spaced and vertically arranged grid bars, wherein surfaces of the grid bars facing the antenna elements form signal reflection surfaces; The first metal frame includes a first frame surface and a second frame surface, the area of ​​the signal reflection surface of the first frame surface is larger than the area of ​​the signal reflection surface of the second frame surface; the first frame surface is at a first preset angle with at least one of the antenna elements, and the second frame surface is at a second preset angle with the corresponding antenna element, and the second preset angle is different from the first preset angle.

2. The vehicle-mounted antenna according to claim 1, characterized in that: The at least two antenna elements include a first antenna element and a second antenna element arranged in a cross shape; The first frame surface includes a first frame surface corresponding to the first antenna element and a second frame surface corresponding to the second antenna element; wherein the area of ​​the signal reflection surface of the first frame surface is different from the area of ​​the signal reflection surface of the second frame surface.

3. The vehicle-mounted antenna according to claim 2, characterized in that: The second frame plane includes a third frame plane corresponding to the first antenna element and a fourth frame plane corresponding to the second antenna element; wherein the area of ​​the signal reflection surface of the third frame plane is different from the area of ​​the signal reflection surface of the fourth frame plane.

4. The vehicle-mounted antenna according to claim 1, wherein: Each of the antenna elements comprises: a main body portion vertically arranged relative to the high-frequency printed circuit board; a first extending portion extending toward both sides at one end of the main body away from the high-frequency printed circuit board, wherein the first extending portion is parallel to the high-frequency printed circuit board; A second extending portion extends from one end of the first extending portion away from the main body portion toward the high-frequency printed circuit board, and the second extending portion is perpendicular to the high-frequency printed circuit board.

5. The vehicle-mounted antenna according to claim 1, wherein: The vehicle-mounted antenna further comprises: A second metal frame, the second metal frame includes a plurality of metal strip groups arranged on a side of the first metal frame away from the antenna element; each of the metal strip groups includes at least one vertically arranged first metal strip, and the first metal strip belonging to a metal strip group is arranged opposite to one of the antenna elements.

6. The vehicle-mounted antenna according to claim 5, characterized in that: The second metal frame further includes at least one second metal strip located between two adjacent metal strip groups, and the height of the second metal strip is smaller than that of the first metal strip.

7. The vehicle-mounted antenna according to claim 6, characterized in that: The second metal frame further includes a circular bottom plate, and the first metal strip and the second metal strip are arranged at the edge of the circular bottom plate and around the first metal frame.

8. The vehicle-mounted antenna according to claim 7, characterized in that: The first metal frame further includes a rectangular bottom plate, which is arranged on the circular bottom plate, and a plurality of the grid bars are arranged along the edge of the circular bottom plate.

9. The vehicle-mounted antenna according to claim 2, characterized in that: The bars on the first frame surface are arranged in a one-to-one correspondence with the bars on the second frame surface, and the size of the bars on the first frame surface is the same as the size of the corresponding bars on the second frame surface, but at least one of the bars on the second frame surface is provided with an opening, and the height and width of the opening are related to the center frequency wavelength of the antenna signal.

10. The vehicle-mounted antenna according to claim 1, characterized in that: A slit is provided between the first frame surface and the second frame surface, and the height of the slit is related to the center frequency wavelength of the antenna signal.

11. The vehicle-mounted antenna according to claim 1, characterized in that: The width and height of the grid bars and the width and height of the slits between two adjacent grid bars are respectively related to the center frequency wavelength of the antenna signal.

12. The vehicle-mounted antenna according to claim 1, wherein: The first preset angle is less than 50 degrees and greater than 40 degrees.

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