Vehicle-mounted antenna

Abstract

Provided in the embodiments of the present disclosure is a vehicle-mounted antenna, comprising: at least two antenna elements, which are vertically arranged on a high-frequency printed circuit board; a phase-shifting feed network, which is fixed on the high-frequency printed circuit board, and is connected to each antenna element; and a first metal frame, which is arranged around the at least two antenna elements on the periphery of the high-frequency printed circuit board, and comprises a plurality of grid bars spaced apart and vertically arranged, wherein the surface of each grid bar that faces the antenna elements is formed as a signal reflection surface; the first metal frame comprises a first frame surface and a second frame surface, and the area of signal reflection surfaces of the first frame surface is greater than the area of signal reflection surfaces of the second frame surface; and a first preset angle is formed between the first frame surface and at least one antenna element, and a second preset angle is formed between the second frame surface and a corresponding antenna element, the second preset angle being different from the first preset angle. By means of the antenna, the gain characteristics of an elevation cut of the antenna can be adjusted, thereby achieving the effect of improving the gain of a low elevation cut of the antenna.

Description

vehicle antenna

[0001] cross-referencing of technologies

[0002] This disclosure claims priority to a prior Chinese patent application filed on November 22, 2024, with application number 202411691027.X. Technical Field

[0003] This disclosure relates to the field of antenna technology, and in particular to a vehicle-mounted antenna. Background Technology

[0004] In the field of satellite communications, to transmit and receive as many satellite signals as possible, antennas must not only possess wide-beam circular polarization coverage but also have high radiation gain at lower elevation angles. For vehicle-mounted communication applications using satellite antennas, coverage of the upper hemisphere, especially within the 0 to 70 degree elevation range, is particularly important.

[0005] However, existing vehicle-mounted antennas can only achieve good gain characteristics above 0 dBi at a 60-degree elevation angle, but cannot achieve radiation requirements above 0 dBi at slightly higher low elevation angles (such as greater than or equal to 60 degrees and less than or equal to 80 degrees). Summary of the Invention

[0006] The purpose of this disclosure is to provide a vehicle-mounted antenna for improving the gain characteristics of the antenna at low elevation angles.

[0007] One embodiment of this disclosure provides a vehicle-mounted antenna, comprising:

[0008] At least two antenna arrays are vertically mounted on a high-frequency printed circuit board;

[0009] A phase-shifting feed network is fixed on the high-frequency printed circuit board and connected to each of the antenna elements respectively;

[0010] A first metal frame is disposed around the at least two antenna arrays on the periphery of the high-frequency printed circuit board, and the first metal frame includes a plurality of spaced and vertically arranged grid strips, the surface of the grid strips facing the antenna arrays being formed as a signal reflecting surface;

[0011] The first metal frame includes a first frame surface and a second frame surface, wherein the area of ​​the signal reflecting surface of the first frame surface is larger than the area of ​​the signal reflecting surface of the second frame surface; the first frame surface is at a first preset angle to at least one of the antenna elements, and the second frame surface is at a second preset angle to the corresponding antenna element, wherein the second preset angle is different from the first preset angle.

[0012] Optionally, the vehicle-mounted antenna, wherein the at least two antenna arrays include a first antenna array and a second antenna array arranged in a cross shape;

[0013] The first frame includes a first frame corresponding to the first antenna array and a second frame corresponding to the second antenna array; wherein the area of ​​the signal reflecting surface of the first frame is different from the area of ​​the signal reflecting surface of the second frame.

[0014] Optionally, in the vehicle-mounted antenna, the second frame includes a third frame corresponding to the first antenna array and a fourth frame corresponding to the second antenna array; wherein the area of ​​the signal reflecting surface of the third frame is different from the area of ​​the signal reflecting surface of the fourth frame.

[0015] Optionally, the vehicle-mounted antenna, wherein each of the antenna elements comprises:

[0016] The main body portion is vertically positioned relative to the high-frequency printed circuit board;

[0017] A first extension portion extends to both sides of the main body portion away from the high-frequency printed circuit board, and the first extension portion is parallel to the high-frequency printed circuit board;

[0018] A second extension portion extends toward the high-frequency printed circuit board from one end of the first extension portion away from the main body portion, and the second extension portion is perpendicular to the high-frequency printed circuit board.

[0019] Optionally, the vehicle-mounted antenna further includes:

[0020] The second metal frame includes a plurality of metal strip groups disposed on the side of the first metal frame away from the antenna array; each metal strip group includes at least one vertically arranged first metal strip, and the first metal strip belonging to one metal strip group is disposed opposite to one of the antenna arrays.

[0021] 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, the height of the second metal strip being less than the height of the first metal strip.

[0022] 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 around the first metal frame at the edge of the circular base plate.

[0023] Optionally, in the vehicle-mounted antenna, the first metal frame further includes a rectangular base plate disposed on the circular base plate, and a plurality of the grid strips are disposed along the edge of the circular base plate.

[0024] Optionally, in the vehicle-mounted antenna, the grating strips on the first frame surface and the grating strips on the second frame surface are arranged in a one-to-one correspondence. The size of the grating strips on the first frame surface is the same as the size of the corresponding grating strips on the second frame surface, but at least one grating strip on the second frame surface is provided with an opening. The height and width of the opening are related to the center frequency wavelength of the antenna signal.

[0025] 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 wavelength of the center frequency point of the antenna signal.

[0026] Optionally, in the vehicle-mounted antenna, the width and height of the grating strips, as well as the width and height of the slits between two adjacent grating strips, are respectively related to the center frequency wavelength of the antenna signal.

[0027] Optionally, in the vehicle-mounted antenna, the first preset angle is less than 50 degrees and greater than 40 degrees. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this disclosure or related technologies, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 is a three-dimensional perspective view of the vehicle-mounted antenna according to an embodiment of this disclosure;

[0030] Figure 2 is an exploded perspective view of the vehicle-mounted antenna according to an embodiment of this disclosure;

[0031] Figure 3 is a top view of the vehicle-mounted antenna according to an embodiment of this disclosure;

[0032] Figure 4 is a schematic diagram illustrating the positional relationship between the antenna array and the first metal frame in the vehicle-mounted antenna according to an embodiment of this disclosure;

[0033] Figure 5 is a three-dimensional structural diagram of the first metal frame;

[0034] Figure 6 is a three-dimensional structural diagram of the second metal frame;

[0035] Figure 7 is a diagram showing the VSWR characteristics of the vehicle-mounted antenna described in the embodiments of this disclosure;

[0036] Figure 8 shows the transmission frequency band radiation pattern of the vehicle-mounted antenna described in the embodiments of this disclosure;

[0037] Figure 9 shows the radiation pattern of the transmission frequency band of the vehicle-mounted antenna described in this embodiment at an elevation angle of 45 degrees;

[0038] Figure 10 shows the radiation pattern of the transmission frequency band of the vehicle-mounted antenna described in this embodiment at an elevation angle of 75 degrees;

[0039] Figure 11 illustrates the vertex axial ratio characteristics of the transmission frequency band of the vehicle-mounted antenna according to the embodiments of this disclosure;

[0040] Figure 12 shows the receiving frequency band radiation pattern of the vehicle-mounted antenna described in the embodiments of this disclosure;

[0041] Figure 13 shows the radiation pattern of the vehicle-mounted antenna receiving frequency band at an elevation angle of 45 degrees using the embodiments of this disclosure;

[0042] Figure 14 shows the radiation pattern of the vehicle-mounted antenna receiving frequency band at an elevation angle of 75 degrees using the embodiments of this disclosure;

[0043] Figure 15 shows the vertex axial ratio characteristic of the receiving frequency band of the vehicle-mounted antenna according to the embodiments of this disclosure. Detailed Implementation

[0044] To make the technical problems, technical solutions and advantages to be solved by this disclosure clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0045] The terms "first," "second," etc., used in this disclosure and in the claims are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same class, not limited in number; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0046] To improve the gain characteristics of the low elevation angle section of the antenna, this disclosure provides a vehicle-mounted antenna. A first metal frame with a non-uniform signal reflecting surface is arranged around the antenna array. By making the area of ​​the signal reflecting surface of the first frame surface, which is at a first preset angle to the antenna array, greater than the area of ​​the signal reflecting surface of the second frame surface, which is at a second preset angle to the antenna array, the signal reflecting surface area on the first frame surface is supplemented, thereby adjusting the gain characteristics of the antenna elevation angle section and achieving the effect of improving the gain of the low elevation angle section of the antenna.

[0047] As shown in Figures 1 and 2, one embodiment of the vehicle-mounted antenna according to this disclosure includes:

[0048] At least two antenna arrays 100 are vertically mounted on a high-frequency printed circuit board 200;

[0049] A phase-shifting feed network 300 is fixed on a high-frequency printed circuit board 200 and connected to each antenna element 100 respectively.

[0050] The first metal frame 400 is disposed around at least two antenna arrays 100 on the periphery of the high-frequency printed circuit board 200, and the first metal frame 400 includes a plurality of spaced and vertically arranged grid strips 10, the surface of the grid strips 10 facing the antenna array 100 is formed as a signal reflecting surface.

[0051] The first metal frame 400 includes a first frame surface 410 and a second frame surface 420. The area of ​​the signal reflecting surface of the first frame surface 410 is larger than the area of ​​the signal reflecting surface of the second frame surface 420. The first frame surface 410 is at a first preset angle to at least one antenna array 100, and the second frame surface 420 is at a second preset angle to the corresponding antenna array 100. The second preset angle is different from the first preset angle.

[0052] The vehicle-mounted antenna of this embodiment comprises a first metal frame 400 surrounding at least two antenna elements 100, which forms the metal boundary of the vibrating electric field generated by the antenna elements 100. Multiple spaced gratings 10 on the first metal frame 400 form a signal reflecting surface. By secondary excitation of the vibrating electric field generated by the antenna elements 100, a transmit / receive signal in a preset frequency band is obtained. In this embodiment, the area of ​​the signal reflecting surface of the first frame surface 410 of the first metal frame 400, which forms a first preset angle with the antenna elements 100, is greater than the area of ​​the signal reflecting surface of the second frame surface 420, which forms a second preset angle with the antenna elements. Therefore, the first metal frame 400 is formed with a non-uniform signal reflecting surface structure, used to supplement the signal reflecting surface area on the first frame surface 410 and adjust the gain characteristics of the antenna elevation sectional area.

[0053] Optionally, as shown in Figures 1 and 2, the at least two antenna elements 100 include a first antenna element 110 and a second antenna element 120 arranged in a cross configuration. Optionally, the first antenna element 110 is configured as a positive 45-degree polarized half-wave antenna element, and the second antenna element 120 is configured as a negative 45-degree polarized half-wave antenna element, that is, the first antenna element 110 and the second antenna element 120 are arranged in a cross configuration with their phase centers overlapping.

[0054] In this embodiment of the present disclosure, the structure and principle of the vehicle-mounted antenna described herein are explained by taking the antenna array 100, which includes 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 only two.

[0055] Referring to Figure 3, in this embodiment of the present disclosure, at least two antenna elements 100 are vertically disposed on a high-frequency printed circuit board 200, and a phase-shifting feed network 300 is disposed on the high-frequency printed circuit board 200. The phase-shifting feed network 300 is connected to the first antenna element 110 and the second antenna element 120 respectively, and is used to divide the transmitted antenna signal into at least two signals with different phases and the same amplitude, and the at least two signals are transmitted to different antenna elements 100 respectively.

[0056] Optionally, the phase-shifting feed network 300 includes a Wilkinson power divider, a phase shifter, and an isolation resistor, which can achieve equal power splitting into two paths. The Wilkinson power divider is used to achieve phase delay. After obtaining the antenna signal from the feed source through the feed 201 on the high-frequency printed circuit board 200, the obtained antenna signal is split 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.

[0057] Optionally, in the phase-shifting feed network 300, the Wilkinson power divider is soldered with resistor 202 between two branch circuits that are respectively connected to the first antenna array 110 and the second antenna array 120.

[0058] In one embodiment of this disclosure, as shown in Figures 1 and 2, each of the antenna elements 100 may optionally include:

[0059] The main body 101 is vertically arranged relative to the high-frequency printed circuit board 200;

[0060] A first extension portion 102 extends to both sides at one end of the main body portion 101 away from the high-frequency printed circuit board 200, and the first extension portion 102 is parallel to the high-frequency printed circuit board 200.

[0061] A second extension portion 103 extends from the end of the first extension portion 102 away from the main body portion 101 toward the high-frequency printed circuit board 200, and the second extension portion 103 is perpendicular to the high-frequency printed circuit board 200.

[0062] In this embodiment of the disclosure, optionally, the first antenna array 110 and the second antenna array 120 have the same shape and size.

[0063] Compared to antenna arrays with a typical "T"-shaped structure, the antenna array in the vehicle-mounted antenna of this embodiment is formed as an "M"-shaped structure with both sides bent downwards. This reduces the radiation aperture compared to an antenna array with the same radiation area but a "T"-shaped structure, thereby improving the gain characteristics of the antenna elevation angle section to a certain extent.

[0064] In this embodiment of the disclosure, for one of the antenna elements (first antenna element 110 and / or second antenna element 120), the first metal frame 400 includes a first frame surface 410 at a first preset angle to the corresponding antenna element, and a second frame surface 420 at a second preset angle to the corresponding antenna element, wherein the area of ​​the signal reflecting surface of the first frame surface 410 is larger than the area of ​​the signal reflecting surface of the 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.

[0065] This implementation method involves secondary excitation of the antenna signal of the antenna array, creating a signal reflecting surface at a specific angle (a first preset angle). The area of ​​this surface is larger than that of signal reflecting surfaces at other angles relative to the antenna array. This supplementation of the signal reflecting surface area at this specific angle achieves the effect of adjusting the gain characteristics of the antenna elevation sectional area. Furthermore, by setting a wider grid on the first frame surface, excellent electromagnetic wave reflection is achieved, while by setting a narrower grid on the second frame surface, electromagnetic wave directing is achieved. Based on the first metal frame with a non-uniform signal reflecting surface, optionally, the gain characteristics at a low elevation angle of 75 degrees can be optimized.

[0066] Referring to Figures 4 and 5, optionally, when 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, based on the coordinate system formed by this reference, the first metal frame 400 includes a first frame surface 411 located at coordinate 0 degrees, a second frame surface 412 located at coordinate -90 degrees, a third frame surface 421 located at coordinate 180 degrees (or -180 degrees), and a fourth frame surface 422 located at coordinate 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 tetrahedral shape, and each frame surface 411 includes a plurality of spaced and vertically arranged grid strips.

[0067] In this embodiment of the present disclosure, as shown in FIG4, optionally, the first frame surface 411 located at coordinate 0 degrees has an angle of 45 degrees (first preset angle) relative to the first antenna array 110, that is, the first frame surface 411 is the first frame surface corresponding to the first antenna array 110; the second frame surface 412 located at coordinate -90 degrees has an angle of 45 degrees (first preset angle) relative to the second antenna array 120, that is, the second frame surface 412 is the first frame surface corresponding to the second antenna array 120.

[0068] Furthermore, the third frame surface 421, located at coordinate 180 degrees, has an angle of 135 degrees relative to the first antenna element 110. This means that the third frame surface 421 is the second frame surface corresponding to the first antenna element 110, and the signal reflecting surface area of ​​the first frame surface 411 is larger than that of the third frame surface 421. Similarly, the fourth frame surface 422, located at coordinate 90 degrees, has an angle of 135 degrees relative to the second antenna element 120. This fourth frame surface 422 is also the second frame surface corresponding to the second antenna element 120, and the signal reflecting surface area of ​​the second frame surface 412 is larger than that of the fourth frame surface 422.

[0069] In this embodiment of the disclosure, the first frame surface 410 includes a first frame surface 411 corresponding to the first antenna element 110 (i.e., at a first preset angle) and a second frame surface 412 corresponding to the second antenna element 120 (i.e., at a second preset angle); optionally, the area of ​​the signal reflecting surface of the first frame surface 411 is different from the area of ​​the signal reflecting surface of the second frame surface 412.

[0070] The second frame surface 420 includes a third frame surface 421 corresponding to the first antenna element 110 (i.e., at a second preset angle), and a fourth frame surface 422 corresponding to the second antenna element 120 (i.e., at a second preset angle); optionally, the area of ​​the signal reflecting surface of the third frame surface 421 is different from the area of ​​the signal reflecting surface of the fourth frame surface 422.

[0071] Referring to Figure 5, in this embodiment of the present disclosure, the first frame surface 411, the second frame surface 412, the third frame surface 421 and the fourth frame surface 422 each include a plurality of spaced and vertically arranged grid bars 10, and a strip-shaped slit is formed between adjacent grid bars 10.

[0072] In one embodiment, optionally, the number of gratings 10 provided on the first frame surface 411 and the second frame surface 412 is less than the number of gratings 10 provided on the third frame surface 421 and the fourth frame surface 422, and the width of the gratings 10 provided on the first frame surface 411 and the second frame surface 412 is greater than the width of the gratings 10 provided on the third frame surface 421 and the fourth frame surface 422. This makes the area of ​​the signal reflecting surface of the first frame surface 411 and the second frame surface 412 greater than the area of ​​the signal reflecting surface of the third frame surface 421 and the fourth frame surface 422. By adopting this arrangement structure, a certain amount of grating 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 angle section.

[0073] In this embodiment of the present disclosure, optionally, referring to FIG5, the grid strips 10 on the first frame surface 411 and the grid strips 10 on the second frame surface 412 are arranged in a one-to-one correspondence. The size of the grid strips 10 on the first frame surface 411 is the same as the size of the corresponding grid strips 10 on the second frame surface 412, but at least one grid strip 10 on the second frame surface 412 is provided with an opening 20. The height and width of the opening 20 are related to the center frequency wavelength of the antenna signal.

[0074] Additionally, in the first frame surface 411, the second frame surface 412, the third frame surface 421, and the fourth frame surface 422 that are sequentially connected to 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 wavelength of the center frequency of the antenna signal.

[0075] By adopting this embodiment, by providing an opening 20 on the grid strip 10 of the second frame 412 and providing a slit 30 between the second frame 412 and the third frame 421, the gain of the antenna elevation section can be further adjusted, thereby achieving the effect of optimizing the gain characteristics of the antenna elevation section.

[0076] Optionally, the plurality of gratings 10 on the third frame surface 421 are evenly arranged, and the plurality of gratings 10 have the same width. The fourth frame surface 422 includes a plurality of gratings 10 with the same width evenly arranged, as well as gratings 10 with different widths from the other gratings 10. Specifically, the gratings 10 on the fourth frame surface 422 that are closer to the first frame surface 411 have a greater width than the other gratings 10 on the fourth frame surface 422, so that the area of ​​the signal reflecting surface of the fourth frame surface 422 is different from the area of ​​the signal reflecting surface of the third frame surface 421, thereby achieving the effect of adjusting the antenna elevation cross-section gain.

[0077] In this embodiment of the present disclosure, 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 strip 10 and the width and width of the slit between two adjacent grid strips 10 are respectively related to the center frequency wavelength of the antenna signal.

[0078] Alternatively, the edge lengths and heights of the first frame 411, the second frame 412, the third frame 421, and the fourth frame 422 are the same, and the edge length is related to the wavelength of the center frequency of the antenna signal.

[0079] In one embodiment, optionally, the length of each edge of the first frame 411, the second frame 412, the third frame 421, and the fourth frame 422 is A1λ, where A1 is between 0.3 and 0.45, and optionally, A1 is 0.38; the height of the first frame 411, the second frame 412, the third frame 421, and the fourth frame 422 is A2λ, where A2 is between 0.14 and 0.2, and optionally, A2 is 0.17. λ is the wavelength of the center frequency of the antenna signal.

[0080] To achieve better gain characteristics in the antenna elevation section, the width of the grid strip 10 on the first frame 411 and the second frame 412 is B1λ, where B1 is between 0.08 and 0.12, and optionally, B1 is 0.1; the width of the slot is B2λ, where B2 is between 0.02 and 0.04, and optionally, B2 is 0.03.

[0081] Optionally, the height of each slit on the first frame surface 411, the second frame surface 412, the third frame surface 421 and the fourth frame surface 422 is the same, such as C1λ; C1 is between 0.12 and 0.17, and optionally, C1 is 0.15.

[0082] 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 slit between adjacent grid bars 10.

[0083] Optionally, the height of the slit 30 between the second frame surface 412 and the third frame surface 421 is D2λ, where D2 is between 0.08 and 0.12, and optionally, D2 is 0.1.

[0084] Optionally, as shown in Figures 1, 2, and 6, the vehicle-mounted antenna further includes:

[0085] The second metal frame 500 includes a plurality of metal strip groups 510 disposed on the side of the first metal frame 400 away from the antenna array 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 disposed opposite to an antenna array 100.

[0086] In one embodiment, the second metal frame 500 may optionally include at least one second metal strip 520 located between two adjacent metal strip groups 510, the height of which is less than the height of the first metal strip 511.

[0087] Optionally, the second metal frame 500 also includes a circular base plate 530, with the first metal strip 511 and the second metal strip 520 arranged around the edge of the circular base plate 530, surrounding the first metal frame 400.

[0088] In this embodiment, multiple first metal strips 511 are respectively arranged at the relative positions of the first antenna array 110 and the second antenna array 120, and multiple first metal strips 511 and multiple second metal strips 520 of different heights are arranged around the periphery of the first antenna array 110 and the second antenna array 120 and around the edge of the circular base plate 530, so that the multiple first metal strips 511 and multiple second metal strips 520 form an annular excitation surface for antenna signals, thereby improving the roundness of the low elevation angle surface of the antenna.

[0089] In this embodiment of the disclosure, optionally, 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 respectively related to the wavelength of the center frequency 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.

[0090] In one embodiment of this disclosure, as shown in Figures 1 and 2, the first metal frame 400 may further include a rectangular base plate 430 disposed on a circular base plate 530, with a plurality of gratings 10 disposed along the edge of the circular base plate 430.

[0091] Optionally, as shown in Figures 1 and 2, at least two antenna elements 100 are fixed to a high-frequency printed circuit board 200 by soldering. The high-frequency printed circuit board 200, in which the antenna elements 100 are mounted, is disposed within a first metal frame 400. The first metal frame 400 is fixed to a circular base plate 530 of a second metal frame 500 via a rectangular base plate 430. Optionally, the vehicle 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 has protruding studs 701. The high-frequency printed circuit board 200 is fixed to the corresponding studs by screws located on its bottom surface passing through the rectangular base plate 430 of the first metal frame 400 and the circular base plate 530 of the second metal frame 500. In addition, the antenna top cover 600 and the antenna bottom cover 700 are fastened together to form an accommodating space, and the antenna array 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 accommodating space.

[0092] Optionally, the high-frequency printed circuit board 200 is provided with a feed 201 connected to the phase-shifting feed network 300, and the radio frequency line 301 connected to the feed 201 passes through the radio frequency line outlet 702 on the antenna base 700 and extends from the vehicle-mounted antenna for connecting the feed source.

[0093] The vehicle-mounted antenna using the above-described structure in this embodiment has a wide operating bandwidth, which can fully cover the S-band. The transmission frequency is between 1980 and 2010 MHz, and the receiving frequency is between 2170 and 2200 MHz. It has an excellent VSWR of less than 1.2 throughout the entire frequency band, and has an excellent vertex gain of more than 4.4 dBi in the antenna band. It also has a half-power beamwidth of more than 125 degrees, as shown in Figures 7 and 8.

[0094] The vehicle-mounted antenna of this embodiment supplements the signal reflection area on the first frame surface (which forms a first preset angle with the antenna array) by making the area of ​​the signal reflection surface on the first frame surface larger than the area of ​​the signal reflection surface on the second frame surface (which forms a second preset angle with the antenna array), thereby adjusting the gain characteristics of the antenna elevation section. As shown in Figure 9, the gain characteristics of the vehicle-mounted antenna of this embodiment in the 45-degree elevation section of the transmission frequency band a, and Figure 10, the gain characteristics in the 75-degree elevation section of the transmission frequency band b, demonstrate that the vehicle-mounted antenna with this structure exhibits an excellent gain of over 2.7 dBi in the 45-degree elevation section, and even in ultra-low elevation sections above 75 degrees, it still achieves an excellent gain of over 0 dBi, significantly improving the upper hemisphere range of the vehicle-mounted antenna signal transmission.

[0095] In addition, the vehicle-mounted antenna using this implementation structure can achieve an axial ratio beamwidth of over 225 degrees and 3dB in the transmission frequency band, and has an excellent axial ratio characteristic of less than 1.5dB in the axial direction. In the reception frequency band, it can achieve a vertex gain of over 3.8dBi and has a half-power beamwidth of over 140 degrees, providing a strong guarantee for the quality of the received signal of the vehicle-mounted antenna, as shown in Figures 11 and 12.

[0096] As shown in Figure 13, the gain characteristic diagram of the vehicle-mounted antenna described in this embodiment of the present disclosure is shown in the 45-degree elevation angle section of the receiving frequency band a, and Figure 14 shows the gain characteristic diagram of the receiving frequency band b at a 75-degree elevation angle section. It can be seen that the antenna can achieve an excellent gain of over 2.6 dBi in the 45-degree elevation angle section, and an excellent gain of over 0.3 dBi in the 75-degree low elevation angle section of the transmitting frequency band. This effectively improves the communication quality of the vehicle-mounted terminal receiving satellite signals.

[0097] In addition, the vehicle-mounted antenna using this implementation structure has a 3dB axial ratio bandwidth 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, thus achieving excellent circular polarization characteristics, as shown in Figure 15.

[0098] Based on the above, the vehicle-mounted antenna described in this embodiment adjusts the gain characteristics of the antenna elevation angle section to improve the gain of the antenna at low elevation angles, and can still achieve high gain and wide-axis ratio circular polarization characteristics at ultra-low elevation angles.

[0099] The above describes the preferred embodiments of this disclosure. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles described in this disclosure, and these improvements and modifications should also be considered within the scope of protection of this disclosure.

Claims

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

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

3. The vehicle-mounted antenna according to claim 2, wherein, The second frame includes a third frame corresponding to the first antenna array and a fourth frame corresponding to the second antenna array; wherein the area of ​​the signal reflecting surface of the third frame is different from the area of ​​the signal reflecting surface of the fourth frame.

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

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

6. The vehicle-mounted antenna according to claim 5, wherein, The second metal frame also includes at least one second metal strip located between two adjacent metal strip groups, the height of the second metal strip being less than the height of the first metal strip.

7. The vehicle-mounted antenna according to claim 6, wherein, The second metal frame also includes a circular base plate, and the first metal strip and the second metal strip are arranged around the first metal frame at the edge of the circular base plate.

8. The vehicle-mounted antenna according to claim 7, wherein, The first metal frame further includes a rectangular base plate disposed on the circular base plate, and a plurality of the grid strips are disposed along the edge of the circular base plate.

9. The vehicle-mounted antenna according to claim 2, wherein, The grid strips on the first frame surface are arranged in a one-to-one correspondence with the grid strips on the second frame surface. The size of the grid strips on the first frame surface is the same as the size of the corresponding grid strips on the second frame surface. However, at least one grid strip on the second frame surface is provided with an opening. 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, wherein, A slit is provided between the first frame surface and the second frame surface, and the height of the slit is related to the wavelength of the center frequency point of the antenna signal.

11. The vehicle-mounted antenna according to claim 1, wherein, The width and height of the grating, as well as the width and height of the slit between two adjacent gratings, are 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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