A GNSS antenna

Abstract

The application provides a GNSS antenna, comprising: a ground plate; an outer ring radiation structure arranged above the ground plate; and a parasitic radiation structure coaxially and spacedly arranged with the outer ring radiation structure; wherein the outer ring radiation structure is arranged around the parasitic radiation structure, and the two structures jointly cover a high frequency band and a low frequency band, the high frequency band is 1560-1610 MHz, and the low frequency band is 1160-1300 MHz; and the outer ring radiation structure and the parasitic radiation structure are both center-symmetric structures. The GNSS antenna provided by the application can realize wide-band coverage with a compact and simple structure, and has high gain and good radiation performance in the whole working frequency band.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and in particular to a GNSS antenna. Background Technology

[0002] With the integrated application of GNSS systems such as GPS, BeiDou, and Galileo, antennas capable of operating in multiple frequency bands, including L1 (approximately 1560-1610MHz) and L2 / L5 (approximately 1160-1300MHz), have become crucial for improving positioning accuracy. However, existing antenna technology faces four major bottlenecks:

[0003] Insufficient bandwidth: Traditional microstrip antennas and other solutions have limited bandwidth and cannot efficiently cover all GNSS frequency bands.

[0004] Bulky structure: The stacking or loading design used to expand bandwidth results in a high antenna profile and large size, making it difficult to integrate into compact platforms such as drones and vehicles.

[0005] Performance compromise: When a single structure covers multiple frequency bands, it is difficult to balance the performance of each frequency band, such as gain and radiation pattern, resulting in poor performance of some frequency bands.

[0006] High cost: The complex structure drives up manufacturing costs, limiting its large-scale commercial application.

[0007] Therefore, developing a high-performance GNSS antenna that combines ultra-wideband, low profile, miniaturization, and low cost is a core technical challenge that urgently needs to be overcome in the field. Summary of the Invention

[0008] The purpose of this invention is to solve the problem of how to design a high-performance GNSS antenna that combines ultra-wideband, low profile, miniaturization, and low cost. This invention provides a GNSS antenna that can achieve wideband coverage with a compact and simple structure, while ensuring high gain and good radiation performance throughout the entire operating frequency band.

[0009] To address the aforementioned technical problems, embodiments of the present invention disclose a GNSS antenna, comprising: a ground plane;

[0010] An outer ring-shaped radiating structure is disposed above the grounding plate; and

[0011] The parasitic radiation structure is coaxial with and spaced apart from the outer ring radiation structure;

[0012] The outer ring radiation structure is arranged around the parasitic radiation structure, and the two work together to cover the high-frequency band and the low-frequency band. The high-frequency band is 1560-1610MHz, and the low-frequency band is 1160-1300MHz.

[0013] Both the outer ring radiation structure and the parasitic radiation structure are centrosymmetric structures.

[0014] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a GNSS antenna, wherein the outer ring radiation structure includes four first radiation elements symmetrically arranged around the parasitic radiation structure, each first radiation element includes a first support structure and a first radiation sheet formed on the first support structure, the first support structure is provided with a first feed point, and the first feed point is electrically connected to the feed network.

[0015] The parasitic radiation structure includes a second support structure and a parasitic radiation sheet formed on the second support structure;

[0016] In this design, the second support structure does not have a direct power supply point, and the parasitic radiation structure obtains excitation from the outer ring radiation structure through electromagnetic coupling.

[0017] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a GNSS antenna, wherein the ground plane is provided with the feed network, the feed network including a ring coupler and two Wilkinson power dividers, the feed network being configured to provide excitation signals with sequential 90° phase differences to four first radiating elements to achieve circularly polarized radiation.

[0018] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a GNSS antenna, wherein the electrical length of the ring coupler is the wavelength of the midpoint frequency between the lowest frequency of the low-frequency band and the highest frequency of the high-frequency band, and the electrical length of the Wilkinson power divider is half the wavelength of the midpoint frequency between the lowest frequency of the low-frequency band and the highest frequency of the high-frequency band.

[0019] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a GNSS antenna, wherein the first support structure is a first PCB board and the second support structure is a second PCB board.

[0020] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a GNSS antenna, wherein the first radiating sheet is printed on the front and / or back of the first PCB board, and the parasitic radiating sheet is printed on the front and / or back of the second PCB board.

[0021] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a GNSS antenna, wherein the first radiating plate forms a first annular structure having at least one opening, the size of which is less than 2 mm.

[0022] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a GNSS antenna, wherein the electrical length of the first radiating plate is one-quarter to one-half of the wavelength of the lowest frequency of the low-frequency band.

[0023] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a GNSS antenna in which the electrical length of the parasitic radiating plate is one-half to one times the wavelength of the lowest frequency of the high-frequency band.

[0024] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a GNSS antenna, wherein the spacing between the first PCB board and the second PCB board is 5-15mm, the height of the second PCB board from the ground plane is 5-15mm, the length of the second PCB board is one-quarter of the wavelength of the lowest frequency of the high-frequency band, the height of the second PCB board is one-quarter of the wavelength of the lowest frequency of the high-frequency band, and the thickness of the second PCB board is less than 2mm.

[0025] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a GNSS antenna, wherein the first PCB board is soldered to the ground plane.

[0026] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a GNSS antenna, which further includes an upper cover and a lower cover, the upper cover and the lower cover being snap-fitted together to form a receiving cavity to receive the ground plane, the parasitic radiation structure and the outer ring radiation structure, the upper cover being provided with a fixing structure to fix the parasitic radiation structure.

[0027] Compared with the prior art, the present invention has at least the following beneficial effects:

[0028] Ultra-wideband coverage: Through the synergistic effect of main (outer ring radiation structure) and parasitic (parasitic radiation structure) coupling, the antenna of this invention achieves good impedance matching (S11<-10dB) in both the low-frequency band of 1160-1300MHz and the high-frequency band of 1560-1610MHz, forming an ultra-wideband coverage of the entire GNSS frequency band, which meets the requirements of multi-mode GNSS receivers.

[0029] Compact and lightweight design: High-frequency coverage is achieved using a passive parasitic radiation structure. This significantly reduces the overall profile and weight of the antenna, making it ideal for integration into space- and weight-constrained automotive electronics, wearable devices, or drones.

[0030] High performance and high efficiency: By optimizing the parasitic radiation structure coupling, the antenna gain is greater than 1.9 dB across the entire operating frequency band, and the axial ratio is less than 3.1 dB over a wide bandwidth, exhibiting excellent radiation efficiency and circular polarization performance. The simplified feed network also reduces signal transmission loss, further improving overall efficiency.

[0031] Low cost and easy to manufacture: The antenna of this invention mainly consists of four identical first PCB boards and one second PCB board, with fewer types of parts, a high degree of standardization, and is easy to mass-produce and automate. Compared with existing solutions that require customization of multiple complex components, the manufacturing cost of this invention is significantly reduced, enhancing its market competitiveness.

[0032] Flexible design and high reliability: The centrally symmetrical structure ensures stable omnidirectional radiation characteristics. The simplified design and fewer connection points improve product reliability and long-term stability. Simultaneously, the tunable design allows the antenna to flexibly adapt to different application scenarios, enhancing the product's versatility.

[0033] To make the above description of the present invention more apparent and understandable, preferred embodiments are described below in conjunction with the accompanying drawings. Attached Figure Description

[0034] Figure 1 A perspective view of the GNSS antenna provided by the present invention is shown;

[0035] Figure 2 A cross-sectional view of the GNSS antenna provided by the present invention is shown;

[0036] Figure 3 A perspective view of the top cover of the GNSS antenna provided by the present invention is shown;

[0037] Figure 4 This invention illustrates a three-dimensional representation of the parasitic radiation structure, outer ring radiation structure, and ground plane of the GNSS antenna provided by this invention. Figure 1 ;

[0038] Figure 5 A perspective view of a first radiating element of a GNSS antenna provided by the present invention is shown;

[0039] Figure 6 A perspective view of the parasitic radiation structure of the GNSS antenna provided by the present invention is shown;

[0040] Figure 7 A perspective view of another first radiating element of the GNSS antenna provided by the present invention is shown;

[0041] Figure 8 This invention illustrates a three-dimensional representation of the parasitic radiation structure, outer ring radiation structure, and ground plane of the GNSS antenna provided by this invention. Figure 2 ;

[0042] Figure 9 The S-parameter diagram of the GNSS antenna provided by the present invention is shown;

[0043] Figure 10 The gain diagram of the GNSS antenna provided by the present invention is shown;

[0044] Figure 11 The axial ratio diagram of the GNSS antenna provided by the present invention is shown.

[0045] The attached diagram is described as follows:

[0046] 100 Top cover; 101 Connector; 102 Connecting hole; 103 Positioning pin; 104 Positioning hole;

[0047] 110 Fixing structure; 111 First fixing component; 112 Second fixing component; 113 L-shaped placement groove; 114 L-shaped snap-fit ​​groove;

[0048] 200 Lower cover; 201 Receiving cavity; 202 Recess; 203 Fastener; 204 Connecting post;

[0049] 300 ground plane; 301 through hole;

[0050] 310 Power supply network; 311 Wilkinson power divider; 312 Ring coupler; 313 Connecting arm; 314 Second bend; 315 Third bend;

[0051] 400 outer ring radial structure;

[0052] 410 First radiating unit; 411 First supporting structure; 412 First radiating sheet; 413 First feed point; 414 First PCB board; 415 First opening; 416 Second opening; 417 First radiating branch; 4171 First segment; 4172 Second segment; 4173 Third segment; 4174 Fourth segment; 4175 Eighth segment; 4176 Ninth segment; 418 Second radiating branch; 4181 Fifth segment; 4182 Sixth segment; 4183 Seventh segment; 419 First soldering point;

[0053] 500 parasitic radiation structure;

[0054] 510 Second support structure; 511 Second PCB board;

[0055] 520 Parasitic radiation patch; 521 First bend; 522 Tenth segment; 523 Eleventh segment; 524 Twelfth segment; 525 Thirteenth segment; 526 Fourteenth segment;

[0056] 600 cable. Detailed Implementation

[0057] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention is presented in conjunction with preferred embodiments, this does not mean that the features of the invention are limited to these embodiments. On the contrary, the purpose of describing the invention in conjunction with embodiments is to cover other options or modifications that may be derived based on the claims of the present invention. To provide a deep understanding of the invention, many specific details will be included in the following description. The invention may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of the invention, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0058] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0059] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of the invention is usually placed in during use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0060] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0061] In the description of this embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0062] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0063] Existing GNSS solutions mostly use ceramic antennas or metal antenna structures with brackets for fixation, which lack sufficient bandwidth to cover the entire frequency band. Therefore, this application's embodiments employ a new antenna structure to improve the operating bandwidth.

[0064] For example, refer to Figures 1 to 3 This invention provides a GNSS antenna. The antenna includes an upper cover 100, a lower cover 200, a ground plane 300, and an outer ring radiating structure 400 and a parasitic radiating structure 500 disposed above the ground plane 300. The upper cover 100 and the lower cover 200 are connected by snap-fit ​​to form a receiving cavity 201. The ground plane 300, the outer ring radiating structure 400, and the parasitic radiating structure 500 are located within the receiving cavity 201. Multiple fixing structures 110 are provided on the side of the upper cover 100 facing the lower cover 200 to fix the parasitic radiating structure 500.

[0065] Combination Figure 3 and Figure 4 The parasitic radiation structure 500 and the outer ring radiation structure 400 are coaxial and spaced apart; the outer ring radiation structure 400 surrounds the parasitic radiation structure 500, and the two work together to cover the high-frequency band (1560-1610MHz) and the low-frequency band (1160-1300MHz); both the outer ring radiation structure 400 and the parasitic radiation structure 500 are centrosymmetric structures.

[0066] Specifically, the outer side of the lower cover 200 has six recesses 202, each recess 202 containing a snap-fit ​​element 203 that protrudes outward. The outer side of the upper cover 100 has a corresponding connector 101 with a connecting hole 102. When the upper cover 100 is placed on top of the lower cover 200, the connector 101 is located within the recess 202, and the snap-fit ​​element 203 passes through the connecting hole 102 to limit the connector 101, thereby achieving a snap-fit ​​connection between the upper cover 100 and the lower cover 200. The outer edge of the inner cavity of the lower cover 200 is provided with four connecting posts 204 spaced apart. The connecting posts 204 are along the height direction of the lower cover 200 (i.e.,...). Figure 2 Extending in the Z direction (as shown), the outer edge of the inner cavity of the upper cover 100 is provided with four positioning posts 103 that correspond one-to-one with the connecting posts 204. The positioning posts 103 have positioning holes 104, and the connecting posts 204 of the lower cover 200 are inserted into the positioning holes 104.

[0067] It should be noted that the embodiments of this application do not limit the number of connectors 101, recesses 202, positioning posts 103, and connecting posts 204, as long as they can connect the upper cover 100 and the lower cover 200 together. For example, there can be four, seven, eight, ten, or more connectors 101, the number of recesses 202 is the same as the number of connectors 101, the number of positioning posts 103 can be five, seven, eight, ten, or more, and the number of connecting posts 204 is the same as the number of positioning posts 103.

[0068] The upper cover 100 has five first fixing members 111 and three second fixing members 112 spaced apart on the side facing the lower cover 200. The first fixing members 111 have an L-shaped placement groove 113, in which the parasitic radiation structure 500 (i.e., the lower surface of the second PCB board 511 described later) is placed. The second fixing members 112 have an L-shaped snap-fit ​​groove 114, in which the parasitic radiation structure 500 (i.e., the upper surface of the second PCB board 511 described later) abuts against the L-shaped snap-fit ​​groove 114, thereby limiting the position of the parasitic radiation structure 500.

[0069] It should be noted that the specific number of the first fixing member 111 and the second fixing member 112 is not limited in the embodiments of this application, as long as the parasitic radiation structure 500 can be fixed. For example, the first fixing member 111 can be three, four, seven or more, and the second fixing member 112 can be four, five, seven or more.

[0070] There is a spacing L1 between the outer ring radiation structure 400 and the parasitic radiation structure 500. Figure 4 As can be seen, the spacing range is 5-15mm (that is, the spacing between the first PCB board 414 and the second PCB board 511, as described later), which is 5.8mm. Of course, L1 can also be 5mm, 5.4mm, 8.8mm, 10mm, 12.5mm, 14.5mm, 15mm, etc. Firstly, after being excited, the outer ring radiation structure 400 resonates and radiates electromagnetic waves in the low-frequency band (i.e., 1160-1300MHz). The electromagnetic field radiated by the outer ring radiation structure 400 induces a current in its near-field region. The parasitic radiation structure 500 is located precisely in this strongly coupled field. When the outer ring radiation structure 400 operates, its electromagnetic field couples to the parasitic radiation structure 500, like "igniting" it remotely, exciting the parasitic radiation structure 500 to generate a current. The frequency of the outer ring radiation structure 400 is close to the natural resonant frequency of the parasitic radiation structure 500, causing the parasitic radiation structure 500 to also resonate strongly, thereby generating a new radiation in the high-frequency band (i.e. 1560-1610MHz), thus covering the entire GNSS frequency band (i.e., low-frequency band 1160-1300MHz and high-frequency band 1560-1610MHz).

[0071] Both the outer ring radiator structure and the parasitic radiation structure 500 adopt a centrally symmetrical structure (in this embodiment, it is quadruple symmetrical, that is, after the outer ring radiator structure and the parasitic radiation structure 500 rotate 90° around their center point O, they can completely coincide with themselves), ensuring that the antenna has uniform radiation characteristics in the horizontal plane.

[0072] This quadruple symmetry structure is an effective method for achieving high-performance, omnidirectional GNSS antennas. The symmetrical structure helps generate a very uniform radiation pattern in the horizontal plane (azimuth plane). This means that the antenna's ability to receive satellite signals is consistent regardless of the vehicle's orientation, ensuring positioning stability. GNSS signals are typically circularly polarized. The quadruple symmetry structure makes it easier to design and achieve good circular polarization (i.e., low axial ratio) over a wide beam range, which is crucial for suppressing multipath effects and improving signal quality. The symmetrical structure ensures that the antenna's input impedance remains stable in different directions, simplifying matching with the feed line and guaranteeing signal transmission efficiency. Furthermore, the symmetrical design is mechanically balanced, and during manufacturing, only one type of unit (e.g., the first PCB board 414 described later) needs to be designed and produced, and then reassembled four times, reducing design and manufacturing costs.

[0073] For example, refer to Figure 4 and Figure 5 The outer ring radiation structure 400 includes four first radiation units 410 symmetrically arranged around the parasitic radiation structure 500. Each first radiation unit 410 includes a first support structure 411 and a first radiation plate 412 formed on the first support structure 411. A first feed point 413 is provided on the first support structure 411 for connection with the feed network 310 described later. Figure 8 (See) Electrical connection.

[0074] For example, in some embodiments, the first support structure 411 is a first PCB board 414. The four first PCB boards 414 have identical structures and are perpendicular to each other to form a square. Adjacent first PCB boards 414 are physically independent and not directly electrically connected. Specifically, adjacent first PCB boards 414 are physically independent and separate physical entities, with a physical distance L2 between them. Figure 4 As can be seen, the physical spacing between two adjacent first PCB boards 414 is less than one-twentieth of the wavelength of the lowest operating frequency (i.e., 1160MHz) of the GNSS antenna.

[0075] For example, the physical spacing between two adjacent first PCB boards 414 can range from 2 to 8 mm. For instance, the physical spacing L2 between two adjacent first PCB boards 414 shown in this embodiment is 6.4 mm. Of course, L2 can also be 2 mm, 3 mm, 5 mm, 8 mm, etc. This embodiment does not limit the specific value of L2. The optimal size can be selected by comprehensive optimization based on actual cases. Of course, those skilled in the art will understand that this size is also related to the dielectric constant of the selected first PCB board 414.

[0076] In other words, the four first PCB boards 414 are not a single complete PCB board. They are four separately manufactured parts, which are then fixed to specific positions on the ground plane 300 by soldering. Although they are eventually assembled into a square, each piece is independent in itself.

[0077] It is understandable that four first PCB boards 414 can be connected without setting physical spacing.

[0078] Simultaneously, a large ring is divided into four smaller units (i.e., four independent first PCB boards 414), each with a shorter electrical length, allowing for a more compact overall structure. This design enables the antenna to be easily formed into circles, rectangles, or other polygons, and of course, a square as shown in the embodiments of this application. This is extremely useful in many applications with shape constraints (such as shark fin antennas, antennas integrated into vehicle bodies). If a single PCB board were used, making it non-circular while ensuring performance continuity would be much more complex.

[0079] In addition, this GNSS antenna only requires the design and production of one first PCB board 414, which is then repeated four times, reducing mold opening and manufacturing costs. During the debugging phase, the coupling strength can be precisely controlled by fine-tuning the spacing between adjacent first PCB boards 414, thereby fine-tuning the antenna's resonant frequency and bandwidth, which is much more convenient than modifying an entire PCB board.

[0080] refer to Figure 5 The length L3 of the first PCB board 414 is less than half the wavelength of the lowest operating frequency (i.e., 1160MHz) of the GNSS antenna. For example, the length L3 of the first PCB board 414 shown in this embodiment is 37mm, but L3 can also be 32mm, 33mm, 35mm, 38mm, etc. The height W1 of the first PCB board 414 is less than one-tenth of the wavelength of the lowest operating frequency (i.e., 1160MHz) of the GNSS antenna. For example, the height W1 of the first PCB board 414 shown in this embodiment is 14mm, but W1 can also be 10mm, 11mm, 12mm, 13mm, etc. The thickness H1 of the first PCB board 414 is less than 2mm. For example, the thickness H1 of the first PCB board 414 shown in this embodiment is 1.0mm, but H1 can also be 0.5mm, 1.4mm, 1.8mm, 1.95mm, etc.

[0081] Those skilled in the art will understand that the specific values ​​of the length L3, thickness H1, and height W1 of the first PCB board 414 are not limited in the embodiments of this application, but are selected according to the electrical length of the first radiating sheet 412.

[0082] The first radiating sheet 412 is printed on the front side of the first PCB board 414, or the first radiating sheet 412 is printed on the back side of the first PCB board 414 (not shown). Alternatively, the first radiating sheet 412 is printed on both the front and back sides of the first PCB board 414, and the first radiating sheet 412 on the front side and the first radiating sheet 412 on the back side are electrically connected through metallized vias (not shown). The first radiating sheet 412 forms a first annular structure with at least one opening, the size of which is less than 2 mm. The electrical length of the first radiating sheet 412 is one-quarter to one-half of the wavelength of the lowest frequency in the low-frequency band (i.e., 1160 MHz).

[0083] For example, the electrical length of the first radiating sheet 412 shown in the embodiments of this application is 120mm, but it can also be 90mm, 98mm, 100mm, 115mm, 122mm, 145mm, 150mm, etc. The optimal size can be selected by comprehensive optimization based on actual cases. Of course, those skilled in the art will understand that this size is also related to the dielectric constant of the selected first PCB board 414 and the size of the first opening 415 and the second opening 416.

[0084] In this embodiment, the first radiating plate 412 forms a first annular structure with two openings, namely a first opening 415 and a second opening 416. The first opening 415 and the second opening 416 introduce a capacitive loading effect, equivalent to connecting a capacitor in series with the annular antenna. This effectively adjusts the antenna's resonant frequency and significantly widens its impedance bandwidth, thereby achieving ultra-wideband performance. It should be noted that the number of openings in the first annular structure is not limited in this embodiment. It can be two openings (first opening 415 and second opening 416) as shown in this embodiment, or it can be a single opening, as long as the electrical length of the first radiating plate 412 is one-quarter to one-half of the wavelength of the lowest frequency in the low-frequency band (i.e., 1160MHz).

[0085] The size of the first opening 415 is less than 2mm. For example, the width W3 of the first opening 415 shown in the embodiment of this application is 1.5mm. Of course, L5 can also be 0.5mm, 1mm, 1.2mm, 1.8mm, 1.95mm, etc. The size of the second opening 416 is less than 2mm. For example, the width W4 of the second opening 416 shown in the embodiment of this application is 1.1mm. Of course, W4 can also be 0.5mm, 1mm, 1.2mm, 1.8mm, 1.95mm, etc.

[0086] In one possible embodiment, the first radiating sheet 412 includes a first radiating branch 417 and a second radiating branch 418. The first radiating branch 417 includes a first segment 4171, a second segment 4172, a third segment 4173, and a fourth segment 4174 that are perpendicular to each other and connected. The first segment 4171 is along the height direction of the first PCB board 414 (i.e., Figure 5 The second segment 4172 extends along the length of the first PCB board 414 (i.e., in the Z direction shown) and toward the ground plane 300. Figure 5 The third segment 4173 extends along the height direction of the first PCB board 414 (i.e., the X direction shown), and extends along the X direction shown. Figure 5 The fourth segment 4174 extends along the length of the first PCB board 414 (i.e., in the Z direction shown) and toward the ground plane 300. Figure 5 Extending in the X direction (as shown), the first segment 4171 and the third segment 4173 extend along the length direction of the first PCB board 414 (i.e., along the X direction). Figure 5 The segments 4172 and 4174 are spaced apart along the height direction of the first PCB board 414 (i.e., the X-direction shown). Figure 5 The second radiating branches 418 are spaced apart in the Z-direction shown. The second radiating branches 418 include a fifth segment 4181, a sixth segment 4182, and a seventh segment 4183 that are perpendicular to and connected to each other. The fifth segment 4181 is arranged along the height direction of the first PCB board 414 (i.e., along the Z-direction shown). Figure 5 (as shown in the Z direction) and extends toward the ground plane 300, and is along the length direction of the first PCB board 414 (i.e., the first segment 4171) and the first PCB board 414. Figure 5 The segments are spaced apart in the X direction (as shown) to form the first opening 415, and the sixth segment 4182 is arranged along the length direction of the first PCB board 414 (i.e., Figure 5 The seventh segment 4183 extends along the height direction of the first PCB board 414 (i.e., the X direction shown), and extends along the X direction shown. Figure 5 The fifth segment 4181 and the seventh segment 4183 extend along the length direction of the first PCB board 414 (i.e., the Z direction shown) and toward the ground plane 300, and are soldered to the ground plane 300 to form the first feed point 413. Figure 5 The seventh segment 4183 and the fourth segment 4174 are spaced apart along the length of the first PCB board 414 to form the second opening 416. (As shown in the X direction)

[0087] The first PCB board 414 also includes a first solder joint 419, which is located along the length direction of the first PCB board 414 with the first power supply point 413 (i.e., ...). Figure 5 (As shown in the X direction) the spacing is set, and the first welding point 419 is welded to the ground plane 300.

[0088] In another possible embodiment, reference Figure 7The first radiating branch 417 also includes an eighth segment 4175 and a ninth segment 4176 that are perpendicular to each other and connected. The eighth segment 4175 is connected to the fourth segment 4174 and runs along the height direction of the first PCB board 414 (i.e., Figure 7 The ninth segment 4176 extends along the length of the first PCB board 414 (i.e., in the Z direction shown) and away from the ground plane 300. Figure 7 Extending in the X direction (as shown), the seventh segment 4183 and the eighth segment 4175 are spaced apart along the length of the first PCB board 414 to form the second opening 416.

[0089] In other words, the embodiments of this application do not limit the specific structure and shape of the first radiating sheet 412, as long as the electrical length of the first radiating sheet 412 is one-quarter to one-half of the wavelength of the lowest frequency (i.e., 1160MHz) in the low-frequency band.

[0090] In this embodiment, the height of the fourth segment 4174 from the ground plane 300 is less than 5mm. For example, in this embodiment, the height H2 of the fourth segment 4174 from the ground plane 300 is 4mm. Of course, H2 can also be 2mm, 2.4mm, 2.8mm, 3mm, 3.5mm, 4.5mm, 4.95mm, etc. At this time, a capacitor is formed between the first radiating plate 412 and the ground plane 300. The size of the capacitor is directly proportional to the area of ​​the plates and inversely proportional to the distance between the plates. By compressing the distance H2 between the first radiating plate 412 and the ground plane 300 to a very small size (i.e., H2 < 5mm), the capacitance value between the first radiating plate 412 and the ground plane 300 is greatly increased. This strong capacitance loading is equivalent to connecting a large capacitor in series at the first opening 415 and the second opening 416, which will be described later. This will significantly change the resonant characteristics of the antenna, allowing the antenna to resonate at a lower frequency with a smaller physical size. This capacitance loading will smooth the impedance curve, so that the S11 parameter can be kept below -10dB over a wider frequency range. Meanwhile, optimized impedance matching ensures efficient energy transmission and improves the overall radiation efficiency of the antenna. This also leads to miniaturization and high integration of the product, broadening the antenna's application scenarios and market competitiveness.

[0091] The other three first PCB boards 414 have the same structure as the first PCB board 414 mentioned above, and will not be described in detail here.

[0092] For example, refer to Figure 4 and Figure 6 The parasitic radiation structure 500 includes a second support structure 510 and a parasitic radiation sheet 520 formed on the second support structure 510; wherein, the second support structure 510 does not have a direct feed point, and it obtains excitation from the outer ring radiation structure 400 through electromagnetic coupling.

[0093] For example, the second support structure 510 is a second PCB board 511, the second PCB board 511 is square, and the height H3 of the second PCB board 511 from the ground plane is 300. Figure 2 As can be seen, the height range of the second PCB board 511 is 5-15mm. For example, H3 shown in this embodiment is 11mm, but H3 can also be 5mm, 5.4mm, 8.8mm, 10mm, 12.5mm, 14.5mm, 15mm, etc. The length L4 of the second PCB board 511 is one-quarter of the wavelength of the lowest frequency (i.e., 1560MHz) in the high-frequency band. For example, the length L4 of the second PCB board 511 shown in this embodiment is 37mm, but L4 can also be 30mm, 32mm, 33mm, 45mm, 48mm, 50mm, etc. The height W2 of the second PCB board 511 is one-quarter of the wavelength of the lowest frequency (i.e., 1560MHz) in the high-frequency band, and is equal to the length L4. The thickness H4 of the second PCB board 511 is less than 2mm. For example, the thickness H4 of the first PCB board 414 shown in this embodiment is 1.9mm, but H4 can also be 0.5mm, 1.4mm, 1.8mm, 1.95mm, etc.

[0094] Those skilled in the art will understand that the specific values ​​of the length L4, thickness H4, and height W2 of the second PCB board 511 are not limited in the embodiments of this application, but are selected according to the electrical length of the parasitic radiation sheet 520.

[0095] The parasitic radiating sheet 520 is printed on the front side of the second PCB board 511, or on the back side of the second PCB board 511 (not shown in the figure), or on both the front and back sides of the second PCB board 511. The parasitic radiating sheet 520 on the front side and the parasitic radiating sheet 520 on the back side are electrically connected through metallized vias (not shown in the figure). The electrical length of the parasitic radiating sheet 520 is half to one time the wavelength of the lowest frequency (i.e., 1560MHz) in the high-frequency band. For example, the electrical length of the parasitic radiating sheet 520 shown in the embodiment of this application is 180mm, but it can also be 150mm, 168mm, 170mm, 175mm, 180mm, etc. The optimal size can be selected by comprehensive optimization according to the actual case. Of course, those skilled in the art will understand that this size is also related to the dielectric constant of the selected second PCB board 511.

[0096] In this embodiment, the parasitic radiating plate 520 is a loop antenna, but it is not limited to this. The parasitic radiating plate 520 can also be a slot antenna, as long as its electrical length is one-half to one times the wavelength of the lowest frequency (i.e., 1560MHz) in the high-frequency band.

[0097] In this embodiment, the parasitic radiating plate 520 has a centrally symmetrical structure. The parasitic radiating plate 520 disposed on one wide side of the second PCB board 511 includes the radiating plate along the width direction of the second PCB board 511 (i.e., Figure 6 The thirteenth segment 525 and fourteenth segment 526 (shown in the Y direction) and a first bend 521 extend from the outer edge of the second PCB board 511. The first bend 521 includes a tenth segment 522, an eleventh segment 523 and a twelfth segment 524 that are perpendicular to each other and connected. The two ends of the eleventh segment 523 connect the tenth segment 522 and the twelfth segment 524. The eleventh segment 523 extends along the width of the second PCB board 511 (i.e., Figure 6 Extending in the Y direction (as shown). The two ends of the tenth segment 522 are connected to the eleventh segment 523 and the thirteenth segment 525 respectively. The two ends of the twelfth segment 524 are connected to the eleventh segment 523 and the fourteenth segment 526 respectively. The thirteenth segment 525 and the fourteenth segment 526 are printed on the outer edge of the second PCB board 511, specifically printed on one wide side of the second PCB board 511. The other wide side and the two long sides of the second PCB board 511 are printed with radiating sheets of the same shape, which together form a centrally symmetrical parasitic radiating sheet 520.

[0098] It should be noted that the shape of the parasitic radiation plate 520 is not limited in the embodiments of this application, as long as the shape is a centrally symmetrical figure and its electrical length is one-half to one times the wavelength of the lowest frequency (i.e., 1560MHz) in the high-frequency band.

[0099] For example, refer to Figure 8 The outer edge of the ground plate 300 is provided with four through holes 301 for connecting with the connecting post 204 of the lower cover 200 to fix the ground plate 300 onto the lower cover 200. The connecting post 204 of the lower cover 200 passes through the through holes 301 of the ground plate 300 and is inserted into the positioning hole 104 of the upper cover 100.

[0100] For example, the ground plane 300 has a power supply network 310 and a circuit output area 320 on the side facing away from the second PCB board 511. The power supply network 310 includes a ring coupler 312 and two Wilkinson power dividers 311. The power supply network 310 is configured to provide excitation signals with sequential 90° phase differences to four first radiation units 410 to achieve circularly polarized radiation. The circuit output area 320 is used to place circuits such as filters and low-noise amplifiers. The cable 600 is connected to the circuit output area 320.

[0101] For example, a first feed point 413 on each first PCB board 414 is soldered to a ground plane 300 and then electrically connected to two Wilkinson power dividers 311 and a ring coupler 312 via connecting arms 313 respectively. The ring coupler 312 has ten second bends 314 to form a symmetrical structure and increase its electrical length, and the Wilkinson power divider 311 has six third bends 315 to form a symmetrical structure and increase its electrical length.

[0102] It should be noted that the shapes of the Wilkinson power divider 311 and the ring coupler 312 are not limited in this application embodiment, as long as they are symmetrical and the electrical length of the ring coupler 312 is the wavelength of the midpoint between the lowest frequency (1160MHz) of the low-frequency band and the highest frequency (1610MHz) of the high-frequency band (i.e., 1385MHz), and the electrical length of the Wilkinson power divider 311 is half the wavelength of the midpoint between the lowest frequency (1160MHz) of the low-frequency band and the highest frequency (1610MHz) of the high-frequency band (i.e., 1385MHz).

[0103] refer to Figure 9 The horizontal axis represents frequency, and the vertical axis represents return loss. For ▽m1, the horizontal axis is 1100MHz and the vertical axis is -10.1dB. For ▽m2, the horizontal axis is 1700MHz and the vertical axis is -10dB. This means that the S11 curve of this GNSS antenna is basically below -10dB in the two frequency bands from 1160MHz to 1300MHz and from 1560MHz to 1610MHz. This indicates that the GNSS antenna works well in these two target frequency bands and achieves broadband coverage.

[0104] refer to Figure 10 The horizontal axis represents frequency, and the vertical axis represents gain. For ▽m1, the horizontal axis is 1160MHz and the vertical axis is 1.9dB; for ▽m2, the horizontal axis is 1320MHz and the vertical axis is 2dB; for ▽m3, the horizontal axis is 1510MHz and the vertical axis is 2dB; and for ▽m4, the horizontal axis is 1700MHz and the vertical axis is 2.3dB. In other words, the gain of this GNSS antenna is above 1.9dB in the two frequency bands from 1160MHz to 1300MHz and from 1560MHz to 1610MHz, and the gain is relatively stable.

[0105] refer to Figure 11The horizontal axis represents frequency, and the vertical axis represents axial ratio. For ▽m1, the horizontal axis is 1160MHz and the vertical axis is 1.7dB. For ▽m2, the horizontal axis is 1610MHz and the vertical axis is 3.1dB. This means that the GNSS antenna achieves good circular polarization with an axial ratio of less than 3.1dB in the frequency bands from 1160MHz to 1300MHz and from 1560MHz to 1610MHz. This implies that the ellipticity of the electromagnetic waves is within an acceptable range, and the antenna can effectively receive circularly polarized signals.

[0106] While the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the invention to these descriptions. Various changes in form and detail can be made by those skilled in the art, including several simple deductions or substitutions, without departing from the spirit and scope of the invention.

Claims

1. A GNSS antenna, characterized in that, include: Flooring; An outer ring-shaped radial structure is located above the grounding plate; as well as The parasitic radiation structure is coaxial with and spaced apart from the outer ring radiation structure; The outer ring radiation structure is arranged around the parasitic radiation structure, and the two work together to cover the high-frequency band and the low-frequency band. The high-frequency band is 1560-1610MHz, and the low-frequency band is 1160-1300MHz. Both the outer ring radiation structure and the parasitic radiation structure are centrosymmetric structures; The outer ring radiation structure includes four first radiation units symmetrically arranged around the parasitic radiation structure. Each first radiation unit includes a first support structure and a first radiation plate formed on the first support structure. A first feed point is provided on the first support structure and the first feed point is electrically connected to the feed network. The parasitic radiation structure includes a second support structure and a parasitic radiation sheet formed on the second support structure; In this design, the second support structure does not have a direct power supply point, and the parasitic radiation structure obtains excitation from the outer ring radiation structure through electromagnetic coupling.

2. The GNSS antenna according to claim 1, characterized in that, The ground plane is provided with the power supply network, which includes a ring coupler and two Wilkinson power dividers. The power supply network is configured to provide excitation signals with sequential 90° phase differences to the four first radiating elements to achieve circularly polarized radiation.

3. The GNSS antenna according to claim 2, characterized in that, The electrical length of the ring coupler is the wavelength of the midpoint between the lowest frequency of the low-frequency band and the highest frequency of the high-frequency band, and the electrical length of the Wilkinson power divider is half the wavelength of the midpoint between the lowest frequency of the low-frequency band and the highest frequency of the high-frequency band.

4. The GNSS antenna according to claim 1, characterized in that, The first support structure is a first PCB board, and the second support structure is a second PCB board.

5. The GNSS antenna according to claim 4, characterized in that, The first radiating sheet is printed on the front and / or back of the first PCB board, and the parasitic radiating sheet is printed on the front and / or back of the second PCB board.

6. The GNSS antenna according to claim 4, characterized in that, The first radiating sheet forms a first annular structure with at least one opening, the size of which is less than 2 mm.

7. The GNSS antenna according to claim 6, characterized in that, The electrical length of the first radiating sheet is one-quarter to one-half of the wavelength of the lowest frequency in the low-frequency band.

8. The GNSS antenna according to claim 4, characterized in that, The electrical length of the parasitic radiating sheet is one-half to one times the wavelength of the lowest frequency in the high-frequency band.

9. The GNSS antenna according to claim 4, characterized in that, The spacing between the first PCB board and the second PCB board is 5-15mm, the height of the second PCB board from the ground plane is 5-15mm, the length of the second PCB board is one-quarter of the wavelength of the lowest frequency of the high-frequency band, the height of the second PCB board is one-quarter of the wavelength of the lowest frequency of the high-frequency band, and the thickness of the second PCB board is less than 2mm.

10. The GNSS antenna according to claim 4, characterized in that, The first PCB board is soldered to the ground plane.

11. The GNSS antenna according to claim 1, characterized in that, It also includes an upper cover and a lower cover, which are snap-fitted together to form a receiving cavity to accommodate the grounding plate, the parasitic radiation structure and the outer ring radiation structure. The upper cover is provided with a fixing structure to fix the parasitic radiation structure.

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