Full-band satellite positioning antenna

Abstract

The invention discloses a full-band satellite positioning antenna, which overcomes the problems of poor antenna consistency and high cost caused by complex structure, increased weight, complex welding process and multiple welding spots of a satellite navigation positioning antenna in the prior art, and comprises an integrated injection molding shell which comprises a top-layer radiating surface and a bottom-layer feed surface, the top-layer radiating surface comprises a first metal tuning branch knot at the inner periphery and a second metal tuning branch knot at the outer periphery, a parasitic unit is arranged at the vertex angle of the top-layer radiating surface, the top-layer radiating surface is electromagnetically coupled with the parasitic unit, and the parasitic unit is embedded with the second metal tuning branch knot; the bottom layer feed surface is provided with a feed probe and a metalized feed hole, and a feed tuning groove is arranged between the feed probe and the metalized feed hole. The antenna can realize wide bandwidth under the condition of small size, the weight of the antenna is reduced, and the manufacturing cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of satellite positioning antennas, and in particular to a full-band satellite positioning antenna. Background Art

[0002] The Global Navigation Satellite System (GNSS) is a space-based radio navigation and positioning system that provides users with all-weather three-dimensional coordinates, velocity, and time information anywhere on Earth's surface or near-Earth space. The system measures the distance between the satellite and the user based on the difference between the satellite signal's transmission time and its arrival time at the receiver, known as the pseudorange. To calculate the user's three-dimensional position and receiver clock bias, pseudorange measurement requires receiving signals from at least four satellites. With the advancement of globalization, satellite navigation systems are finding applications in various fields, including aviation, automotive navigation, communications, surveying and mapping, and entertainment.

[0003] Antennas, as the terminal signal receiving components of satellite navigation and positioning systems, have a direct impact on the overall system's performance. Currently, mainstream satellite navigation and positioning antennas have the following flaws and shortcomings: To ensure miniaturization and full-band coverage, satellite navigation and positioning antennas typically use ceramic materials and high-frequency circuit board patch antennas. Ceramic patch antennas typically expand their bandwidth by adjusting the dimensions of the silver layers of the upper and lower layers. This laminated design is heavy and complex to manufacture. Patch antennas using high-frequency circuit boards are typically single-layer, expanding their bandwidth through a grounded coupling element on the radiating surface. This results in high costs, and the grounded coupling element increases the number of parts and complicates the soldering process.

[0004] For example, the Chinese Patent Office published patent CN118645806A on September 13, 2024, describing a multi-frequency positioning antenna made of laminated ceramic. This antenna utilizes a double-layer ceramic structure with a strategically placed radiating element to achieve multi-frequency positioning. This results in a smaller antenna with higher performance. However, the laminated structure also suffers from the heavy weight and complex manufacturing process. Summary of the Invention

[0005] The purpose of the present invention is to overcome the problems of satellite navigation positioning antennas in the prior art, such as complex structure, increased weight, complex welding process, and multiple welding points resulting in poor antenna consistency and high cost. A full-band satellite positioning antenna is provided, which can enable the antenna to achieve a wider bandwidth in a smaller size, reduce the weight of the antenna, and reduce the production cost.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: A full-band satellite positioning antenna comprises an integral injection-molded shell, the integral injection-molded shell comprising a top radiating surface and a bottom feeding surface, the top radiating surface comprising a first metal tuning branch for adjusting the high-frequency portion of the positioning antenna and a second metal tuning branch for adjusting the low-frequency portion of the positioning antenna, a parasitic unit being provided at a top corner of the top radiating surface, the top radiating surface being electromagnetically coupled to the parasitic unit, and the parasitic unit being engaged with the second metal tuning branch; a feeding probe and a metallized feeding hole being provided on the bottom feeding surface, and a feeding tuning slot being provided between the feeding probe and the metallized feeding hole.

[0007] While maintaining the performance of the positioning antenna, this invention utilizes a plastic metallization process to integrate the antenna's radiating surface, ground coupling unit, grounding post, and feed probe into a single component. This simplifies the manufacturing process, reduces antenna weight, and lowers material and production costs. The positioning antenna boasts a compact structure that can be fabricated using PCB processing technology, resulting in low manufacturing costs. Furthermore, without complex cascade circuit structures, the antenna exhibits low losses and high antenna gain.

[0008] Preferably, the first metal tuning branch includes an inner concave branch and an outer epitaxial branch connected to each other, the inner concave branch and the outer epitaxial branch are connected through a first branch, the outer epitaxial branch includes an inclined branch and a second branch arranged on both sides of the inclined branch, the second branch is connected to the first branch.

[0009] Preferably, the second metal tuning branch includes a parasitic branch embedded in the parasitic unit and a convex branch connected to the parasitic branch, the parasitic branch and the convex branch are connected through a third branch, the convex branch is positioned opposite to the concave branch, and a metallized feed hole is provided between the convex branch and the concave branch.

[0010] Preferably, the parasitic unit comprises a disk structure, and coupling branches are provided at both ends of the disk structure.

[0011] Preferably, the bottom feeding surface is a U-shaped structure, the metallized feeding hole is arranged on the periphery of the U-shaped structure, the inner periphery of the U-shaped structure is formed into a whole with the feeding probe through metallization, four-point feeding is performed to realize circularly polarized radiation, and the feeding probe is installed inside the one-piece injection-molded shell; the feeding tuning slot is arranged between the inner periphery and the outer periphery of the U-shaped structure.

[0012] Preferably, the parasitic branch includes an arc branch and fourth branches arranged at both ends of the arc branch, the fourth branch is connected to the third branch, and the angle between the two fourth branches is 90 degrees.

[0013] Preferably, the one-piece injection-molded shell is a square structure with four top corners cut off, a grounding column is provided at the top corner of the bottom feeding surface, the outer side of the disc structure is metallized to form a whole with the grounding column at the corresponding position, and the angle between the two coupling branches at both ends of the disc structure is 90 degrees.

[0014] Preferably, there are four feeding probes, which are respectively arranged on the center line of each side of the integral injection-molded housing, and the four feeding probes are centrally symmetrically distributed.

[0015] The feeding current path is the bottom feeding surface connected by four feeding probes, bypassing the feeding tuning slot and reaching the top radiating surface through the metallized feeding hole. At this time, by adjusting the length of the feeding tuning slot, the length of the current path can be adjusted to match the corresponding frequency (when the current path length reaches about one-quarter of the wavelength of the corresponding frequency, the radiation efficiency is optimal).

[0016] Preferably, the four feeding points simultaneously apply equal-amplitude excitation signals with a phase difference of 90° to form circularly polarized radiation.

[0017] Preferably, the grounding post and the feeding probe are integrally formed by injection molding, and the top radiation surface and the bottom feeding surface are provided with through holes of the same size and opposite positions.

[0018] Therefore, the present invention has the following beneficial effects: 1. By introducing two metal tuning branches into the top radiating surface of the full-band satellite positioning antenna, high and low frequencies can be adjusted simultaneously, which can stimulate higher-order resonant modes and combine them with the main mode. These modes interact with each other, effectively expanding the bandwidth of the positioning antenna and realizing a full-band positioning antenna.

[0019] 2. Metallized feeding holes are set on the periphery of the bottom radiation surface to adjust the impedance. The inner periphery is integrated with the feeding probe through metallization to achieve four-point feeding, which can significantly reduce the axial ratio and enable the antenna to maintain a small axial ratio value (such as less than 3 dB) throughout the entire operating frequency band, thereby improving the antenna's reception accuracy and effectively expanding the antenna's circular polarization bandwidth and impedance bandwidth.

[0020] 3. The parasitic units at the four corners interact with the top radiating surface through electromagnetic coupling. By adjusting the size, position and shape of the parasitic units, additional resonance points can be introduced near the main frequency, thereby expanding the bandwidth of the antenna.

[0021] 4. By adjusting the size and position of the four feed tuning slots, the current path between the feed probe and the metallized feed hole can be adjusted, so that the antenna can achieve a wider bandwidth in a smaller size.

[0022] 5. Digging a hole in the middle of the antenna's radiating surface can reduce the use of materials, thereby reducing warping caused by uneven shrinkage during the cooling process, while having less impact on the transmission of high-frequency current. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the overall structure of the full-band satellite positioning antenna in the present invention.

[0024] Figure 2 This is a schematic diagram of the top structure of the full-band satellite positioning antenna in the present invention.

[0025] Figure 3 This is a schematic diagram of the underlying structure of the full-band satellite positioning antenna of the present invention.

[0026] Figure 4 Schematic diagram of the distribution of feeding probes of the full-band satellite positioning antenna in the present invention.

[0027] In the figure: 1. One-piece injection-molded shell; 2. Top-layer radiation surface; 3. Bottom-layer feeding surface; 4. Feed probe; 5. Grounding column; 6. Parasitic unit; 7. Feed tuning slot; 8. Metallized feed hole; 9. First metal tuning branch; 10. Second metal tuning branch; 11. Coupling branch; 12. Through hole; 13. Concave branch; 14. First branch; 15. Inclined branch; 16. Second branch; 17. Convex branch; 18. Third branch; 19. Arc branch; 20. Fourth branch; 21. Disc structure. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments: Example 1: This embodiment provides a full-band satellite positioning antenna. While ensuring antenna performance, it uses a plastic metallization process to integrally mold the antenna's radiating surface, ground coupling unit, ground post, and feed probe into a single component. This simplifies the manufacturing process, reduces the antenna's weight, and lowers material and production costs.

[0029] like Figure 1 As shown, the full-band satellite positioning antenna includes an integral injection-molded housing 1 , the top and bottom layers of which are both metal surfaces, and a feeding probe 4 is provided inside the integral injection-molded housing.

[0030] Among them, the antenna pattern of the top metal surface includes parasitic units 6 at four top corners and a top radiation surface 2. The top radiation surface is in the shape of a U-shaped ...

[0031] The antenna pattern of the bottom metal surface is a bottom feeding surface 3, which is in the shape of a U-shaped ...

[0032] In this embodiment, the U-shaped structures of the top and bottom radiation surfaces are rectangular U-shaped structures. In other embodiments, the U-shaped structures of the top and bottom radiation surfaces may also be circular U-shaped structures.

[0033] The full-band satellite positioning antenna provided in this embodiment utilizes a plastic metallization process to integrally mold the antenna's radiating surface, ground coupling unit, ground post, and feed probe into a single component, while ensuring antenna performance. This simplifies the manufacturing process, reduces antenna weight, and lowers material and production costs.

[0034] The specific structure of the full-band satellite positioning antenna provided by this embodiment is further described below.

[0035] (1) Top radiation surface.

[0036] The top radiation surface is a square structure, including an inner first metal tuning branch and an outer second metal tuning branch. A parasitic unit is provided at the top corner of the top radiation surface. The top radiation surface is electromagnetically coupled to the parasitic unit, and the parasitic unit is partially embedded in the second metal tuning branch.

[0037] The antenna pattern of the top radiating surface primarily influences antenna radiation performance. To achieve full-band coverage for satellite positioning antennas, the antenna's main frequency is controlled by the dimensions of the top radiating surface. The antenna's low-frequency wavelength is longer and is primarily controlled by the length of the outer second tuning branches. The antenna's high-frequency wavelength is shorter and is primarily controlled by the length of the inner first tuning branches. By introducing two different tuning branches into the antenna structure, higher-order resonant modes are excited and combined with the main mode. The interaction of these modes effectively expands the antenna's bandwidth.

[0038] Specifically: like Figure 2 As shown, there are four first metal tuning branches, each with the same structure. The first metal tuning branches include a concave branch 13, an epitaxial branch, and two first branches 14. One end of the epitaxial branch is connected to the concave branch via a first branch, and the other end of the epitaxial branch is connected to the next first metal tuning concave branch via another first branch. The four first metal tuning branches are connected in this manner to form a closed loop.

[0039] The extended branch includes an inclined branch 15 and two second branches 16. The angle between the two second branches is 90 degrees. The second branches are arranged at both ends of the inclined branch. One second branch is connected to the concave branch through the first branch, and the other second branch is connected to the next first metal-tuned concave branch through the first branch.

[0040] There are four second metal tuning branches, each with the same structure. The second metal tuning branches include two third branches 18, a parasitic branch embedded in the parasitic unit, and a convex branch 17 connected to the parasitic branch. One end of the parasitic branch is connected to the convex branch via a third branch, and the other end of the parasitic branch is connected to the convex branch of the next second metal tuning branch via another third branch. The four first metal tuning branches are connected in sequence in this manner to form a closed loop. The convex branch is opposite to the concave branch of the first metal tuning branch and has the same length. A metallized feed hole is provided between the convex branch and the concave branch.

[0041] Among them, the parasitic branches include an arc branch 19 and two fourth branches 20. The two fourth branches are respectively arranged on both sides of the arc branch. The angle between the two fourth branches is 90 degrees. One of the fourth branches is connected to the convex branch through the third branch, and the other fourth branch is connected to the convex branch of the next second metal tuning branch through the third branch.

[0042] There are four parasitic units, located at the four corners of the integrally molded housing. These four units share a common structure, with adjacent units separated by external protruding branches. Each unit comprises a disc structure 21 (with an arc-shaped interior and a cut-off corner on the exterior, mirroring the cut-off corner of the integrally molded housing) and two coupling branches 11, each 90 degrees from the other. The two coupling branches are positioned at opposite ends of the disc structure, with the inner arc of the disc structure having the same curvature as the arc branch and facing each other. The coupling branch is positioned opposite the second branch.

[0043] The parasitic units at the four top corners interact with the top radiating surface through electromagnetic coupling. By adjusting the size, position and shape of the parasitic units, additional resonance points can be introduced near the main frequency, thereby expanding the bandwidth of the antenna.

[0044] In this embodiment, the inward-recessed branch, the first branch, the inclined branch, and the second branch are all of varying lengths; the third branch, the outward-convex branch, the arcuate branch, and the fourth branch are all of varying lengths. The inclined branch, the disc structure, the arcuate branch, and the grounding post are all located on the diagonal of the integrally molded housing; the centerlines of the outward-convex and inward-recessed branches coincide with the centerlines of the sides of the integrally molded housing.

[0045] (2) Bottom feeding surface.

[0046] like Figure 3 and Figure 4 As shown, a feeding probe, a metallized feeding hole and a feeding tuning slot are provided on the bottom feeding surface, and the feeding tuning slot is provided between the feeding probe and the metallized feeding hole.

[0047] The antenna pattern on the bottom metal surface primarily influences the antenna's S-parameter performance and is used to adjust impedance matching and feed type. Four metallized feed holes are positioned on the periphery, while the inner periphery is integrated with the feed probe through metallization, enabling four-point feeding. The bottom feed surface has a U-shaped structure, with metallized feed holes positioned around the periphery to adjust impedance. The inner periphery of the U-shaped structure is integrated with the feed probe through metallization, enabling four-point feeding to achieve circularly polarized radiation. Four-point feeding achieves more stable circular polarization. By applying equal-amplitude excitation signals with 90° phase shifts at the four feed points, good right-hand circular polarization (RCP) or left-hand circular polarization (LCP) can be achieved, thereby improving circular polarization purity. This design significantly reduces the axial ratio, allowing the antenna to maintain a low axial ratio (e.g., less than 3 dB) throughout the entire operating frequency band, thereby improving reception accuracy and effectively extending the antenna's circular polarization bandwidth and impedance bandwidth.

[0048] The feed probe is installed inside the one-piece injection-molded housing, and the feed tuning slot is set between the inner and outer peripheries of the U-shaped structure. The one-piece injection-molded housing is a square structure with four corners cut off, in which the four corners of the bottom feeding surface are all provided with grounding 5. The outer side of the disc structure is metallized to form a whole with the grounding posts at the corresponding positions. The parasitic unit is integrated with the grounding post through metallization, which can change the reactance characteristics of the antenna and optimize the impedance matching. The grounding post can introduce additional resonant modes through coupling, thereby widening the bandwidth.

[0049] There are four feed probes, one located on the centerline of each side of the one-piece injection-molded housing. When the one-piece injection-molded housing is square, the four feed probes are symmetrically distributed around the center. The top radiating surface is not fed directly by the four feed probes. Instead, the feed current path passes through the bottom feed surface connected by the four feed probes, bypassing the feed tuning slots and reaching the top radiating surface through the metallized feed holes. At this time, by adjusting the size and position of the four feed tuning slots, the current path between the feed probes and the metallized feed holes can be adjusted to match the corresponding frequency, allowing the antenna to achieve a wider bandwidth with a smaller size. Radiation efficiency is optimal when the current path length is approximately one-quarter of the wavelength of the corresponding frequency.

[0050] (3) One-piece injection molded housing.

[0051] The grounding column and the feeding probe are integrally formed by injection molding to obtain an integral injection molded shell, wherein the top radiation surface and the bottom feeding surface are both provided with through holes 12 of the same size and opposite positions, which is equivalent to a hollow hole in the integral injection molded shell.

[0052] Hollowing holes in one-piece injection-molded housings takes advantage of the phenomenon that high-frequency currents flow primarily on the surface of a conductor. The skin effect becomes more pronounced as the frequency increases. Holing the center of the antenna's radiating surface reduces material usage and minimizes the impact on high-frequency current transmission. Furthermore, flat injection-molded parts are prone to warping due to uneven shrinkage during cooling. Holing the center reduces material usage, thereby minimizing warping caused by uneven shrinkage during cooling. Therefore, hollowing holes in one-piece injection-molded housings reduces antenna deformation, reduces weight, saves material, and lowers costs.

[0053] Based on the above, the full-band satellite positioning antenna provided in this embodiment has the following beneficial effects: 1. By introducing the first metal tuning branch and the second metal tuning branch into the top radiating surface of the full-band satellite positioning antenna, higher-order resonant modes can be excited and combined with the main mode. These modes interact with each other, effectively expanding the bandwidth of the positioning antenna and realizing a full-band positioning antenna.

[0054] 2. The parasitic units at the four corners interact with the top radiating surface through electromagnetic coupling. By adjusting the size, position and shape of the parasitic units, additional resonance points can be introduced near the main frequency, thereby expanding the bandwidth of the antenna.

[0055] 3. By adjusting the size and position of the four feed tuning slots, the current path between the feed probe and the metallized feed hole can be adjusted, which can enable the antenna to achieve a wider bandwidth in a smaller size.

[0056] 4. Digging a hole in the center of the antenna's radiating surface reduces material usage and minimizes the impact on high-frequency current transmission. Flat injection molded parts are prone to warping during the cooling process due to uneven shrinkage. Digging a hole in the center reduces material usage, thereby reducing warping caused by uneven shrinkage during cooling.

[0057] Example 2: This embodiment provides a method for manufacturing a full-band satellite positioning antenna, which is used to manufacture the full-band satellite positioning antenna provided in Example 1, and further illustrates the technical effects of the full-band satellite positioning antenna.

[0058] This embodiment provides a method for manufacturing a full-band satellite positioning antenna, comprising the following steps: Step 1: The full-band satellite positioning antenna is integrally molded using high-temperature resistant plastic with a stable dielectric constant (such as PPO, PPS, etc.) to obtain an integral injection-molded shell.

[0059] The injection molding process can form the feed probe and the ground column into one piece, eliminating the welding process and reducing the number of parts, while also supporting the bottom metal surface and the top metal surface.

[0060] Step 2: After the plastic parts are molded, the one-piece injection-molded shell is electroplated as a whole, and metal is attached to the top and bottom layers of the one-piece injection-molded shell to obtain top and bottom metal surfaces to ensure the conductive performance of the full-band satellite positioning antenna.

[0061] Step 3: Laser engrave the antenna pattern (including the top radiating surface, bottom feeding surface, through-holes, feed probes, and ground posts).

[0062] The top radiating surface includes four inner first metal tuning branches and four outer second metal tuning branches. The four first metal branches are connected end to end to form a single unit, and the four second metal branches are connected end to end to form a single unit. Parasitic units are located at the top corners of the top radiating surface. There are four parasitic units in total. Each parasitic unit has the same shape, consisting of two coupling branches and a central circular disc. The outer ring of the central circular disc is metallized to form a single unit with the four grounding posts at the top corners of the integral injection-molded housing.

[0063] The bottom feeding surface is a U-shaped structure with four metallized feeding holes on the periphery of the U-shaped structure. The inner periphery of the U-shaped structure is metallized to form a whole with the four feeding probes. There is a feeding tuning slot between the metallized feeding hole and the feeding probe.

[0064] Step 4: After electroplating, the bottom feeding surface and the top radiating surface are thickened, and the non-antenna part is stripped to obtain an integrally molded plastic metallized full-band satellite positioning antenna.

[0065] The resulting plastic metallized full-band satellite positioning antenna is one-third the weight of a ceramic antenna of the same size and half the cost of a high-frequency circuit board.

[0066] This solves the problems of existing antennas, such as complex structure, increased weight, complicated welding processes, poor antenna consistency due to multiple solder joints, and high material and production costs. While maintaining the performance of a full-band satellite positioning antenna, this design utilizes a plastic metallization process to integrate the antenna's radiating surface, ground coupling unit, ground post, and feed probe into a single component, simplifying the manufacturing process, reducing antenna weight, and lowering material and production costs.

[0067] In this embodiment, the top radiation surface and the bottom feeding surface are both symmetrical structures (left-right symmetrical, top-bottom symmetrical, and if the full-band satellite positioning antenna is a square structure, it is centrally symmetrical).

[0068] Positioning antennas require a good axial ratio, which can be understood as a symmetrical radiation pattern and symmetrical radiated energy, resulting in a 3D pattern that is approximately a perfect circle. The axial ratio of a satellite positioning antenna is an important indicator of its polarization performance. The lower the axial ratio, the higher the polarization purity of the antenna, and the more accurate the reception of satellite signals.

[0069] Antennas with low axial ratios can more effectively receive satellite signals and reduce cross-polarization interference, thereby improving the signal-to-noise ratio and enhancing signal reception quality. A lower axial ratio helps antennas better suppress multipath effects. Multipath refers to the phenomenon where satellite signals, after being reflected or refracted, reach the receiving antenna and interfere with the direct signal. Low axial ratio antennas are more effective at suppressing these reflected signals, thereby reducing positioning errors. Low axial ratio antennas also provide a more stable phase center, which is crucial for high-precision positioning applications. Phase center stability directly affects measurement accuracy. A stable phase center reduces measurement errors and improves positioning reliability.

[0070] Taking all of the above factors into account, GNSS antennas with low axial ratios can provide more accurate signal reception, thereby improving the positioning accuracy of GNSS systems. In fields requiring high-precision positioning, such as geological surveys and engineering surveying, using GNSS antennas with low axial ratios can yield more reliable and accurate positioning data. Therefore, the full-band satellite positioning antenna fabricated in this embodiment utilizes a symmetrical structure across all technical aspects, resulting in a lower axial ratio and higher positioning accuracy.

[0071] (1) Bottom feeding surface.

[0072] The antenna pattern of the bottom feed plane affects the S-parameter performance of a full-band satellite positioning antenna. To adjust impedance matching, the resistance, capacitance, and inductance (RCI) characteristics of the bottom feed, as well as the current path, can be adjusted by adjusting the size of the U-shaped structure of the bottom feed plane. The width of the bottom feed plane affects the distributed inductance and distributed capacitance of the feed network. A wider feed plane typically has smaller distributed inductance and larger distributed capacitance, while a narrower feed plane has the opposite. This change alters the impedance characteristics of the feed network, thereby affecting the input impedance of the full-band satellite positioning antenna.

[0073] In this embodiment, the width of the bottom feed surface can be adjusted by adjusting the distance between the inner and outer peripheries of the U-shaped structure of the bottom feed surface. By adjusting the width of the bottom feed surface, the impedance of the feed network can be changed to better match the impedance of the transmission line. For example, if the feed surface is too wide, the impedance of the feed network may be too low, mismatching the impedance of the transmission line, resulting in large reflections and energy loss. Appropriately reducing the width of the feed surface can increase the impedance of the feed network, bringing it closer to the impedance of the transmission line, thereby achieving better impedance matching and reducing reflections and energy loss.

[0074] The size of the feed surface will also affect its distributed inductance and capacitance: a larger feed surface area will increase the distributed capacitance and reduce the distributed inductance, and vice versa, it will reduce the distributed capacitance and increase the distributed inductance. This change will affect the impedance characteristics of the feed network, and thus affect the input impedance of the antenna. Adjusting the size of the feed surface can optimize the impedance of the feed network so that it better matches the radiating part of the antenna. For example, increasing the area of the feed surface can increase the distributed capacitance of the feed network and reduce its impedance, which helps to match it with low-impedance transmission lines. Reducing the area of the feed surface can increase the impedance of the feed network, making it more suitable for high-impedance transmission lines, thereby achieving better impedance matching and improving the radiation efficiency of the antenna. In this embodiment, the area of the bottom feed surface can be adjusted by adjusting the inner and outer circumferences of the U-shaped structure of the bottom feed surface.

[0075] (2) Top radiation surface.

[0076] The antenna pattern of the top radiating surface primarily influences the antenna's radiation performance. The high-frequency portion of a full-band satellite positioning antenna has a shorter wavelength, primarily controlled by the length of the first metal tuning branch in the inner circle. The low-frequency portion has a longer wavelength, primarily controlled by the length of the second metal tuning branch in the outer circle. The inner circle of the U-shaped element is still a rectangle, with a concave portion extending inward in each of the four directions. The first metal tuning branches at the four corners are the outward-extending branches. By adjusting the size of the inner circle and the length of the first metal tuning branches, the size of the top radiating surface can be adjusted, thereby adjusting the radiation frequency and bandwidth of the full-band satellite positioning antenna.

[0077] The size of the top radiating surface is closely related to the radiation frequency. The larger the top radiating surface, the lower the antenna's resonant frequency. This is because a larger radiating surface increases the antenna's physical size, which in turn increases the resonant wavelength, leading to a lower radiation frequency. For example, in a microstrip antenna, the patch length is approximately half the wavelength of the medium. Therefore, changing the patch length (and, therefore, the radiating surface size) directly affects the antenna's operating center frequency. The effect of radiating surface size on bandwidth is more complex. To a certain extent, increasing the radiating surface can increase the antenna's bandwidth. This is because a larger radiating surface provides more space for optimizing current and electromagnetic field distribution, thereby improving the antenna's impedance matching characteristics and maintaining good performance over a wider frequency range. However, if the radiating surface is too large, the antenna's Q factor may decrease, which in turn narrows the bandwidth.

[0078] The influence of the first metal tuning branch on the antenna radiation frequency and bandwidth: Radiation frequency: The extended branches will change the resonant frequency of the full-band satellite positioning antenna. The length and position of the extended branches will affect the electrical length of the antenna, thereby adjusting the radiation frequency.

[0079] Bandwidth: The addition of the first metal tuning branch can significantly increase the antenna's bandwidth. In this embodiment, the first metal tuning directly includes multiple branches of different lengths. These multiple branches can introduce multiple resonant modes, allowing the antenna to operate over a wider frequency range. Furthermore, branches of different lengths and positions produce a coupling effect, further broadening the antenna's bandwidth. For example, by designing branches with multiple different lengths, this embodiment can enable the antenna to cover multiple frequency bands or achieve a wider single-band bandwidth.

[0080] The impact of the through holes on the top radiating surface on the antenna radiation frequency and bandwidth: Radiation Frequency: Introducing vias in the top radiating surface alters the antenna's current distribution and electromagnetic field distribution, thereby affecting the resonant frequency. This alters the antenna's effective electrical length and the distribution of capacitance and inductance, typically lowering the antenna's resonant frequency. This is because the slots increase the current path, effectively extending the antenna's effective length.

[0081] Bandwidth: Introducing through-holes in the top radiating surface is an effective way to broaden an antenna's bandwidth. This creates a new resonance point, allowing the antenna to operate over a wider frequency range. Furthermore, through-holes improve the antenna's impedance matching, reducing reflections and energy loss, thereby increasing bandwidth. For example, by removing a slot from a rectangular patch, the antenna can generate a resonance point at a lower frequency than a conventional rectangular patch, thereby extending the antenna's bandwidth.

[0082] (3) Hollow hole in the full-band satellite positioning antenna.

[0083] In this embodiment, a hole is hollowed out in the integral injection-molded shell of the full-band satellite positioning antenna, that is, there is a through hole between the top radiation surface and the bottom feeding surface.

[0084] Digging holes in the inner circle of the feed plane changes the electric field distribution and current path in that area, thereby affecting the distributed inductance and capacitance of the feed network. This reduces the distributed capacitance and increases the distributed inductance, thereby changing the impedance characteristics of the feed network. By digging holes in the inner circle of the feed plane, the impedance of the feed network can be adjusted to better match the impedance of the transmission line. For example, in some cases, digging holes can reduce the distributed capacitance of the feed network and increase its impedance, thereby reducing the impedance difference with the transmission line, lowering the reflection coefficient, and improving the impedance matching and radiation efficiency of the antenna, thereby achieving impedance matching.

[0085] Impedance matching has an important impact on the performance of the antenna, which is mainly reflected in the following aspects: Improve signal transmission efficiency and reduce signal reflection: When impedance matching is achieved between the antenna and the feeder, the signal will not be reflected during transmission, thereby reducing energy loss and improving signal transmission efficiency.

[0086] Maximum power transfer: According to the maximum power transfer theorem, when the impedance between the antenna and the transmission line or transceiver is matched, the system can achieve maximum energy transfer efficiency.

[0087] Expand signal coverage and optimize antenna radiation direction: Good impedance matching ensures that the RF signal energy transmitted between the antenna and the feeder is utilized to the greatest extent possible, thereby improving signal transmission efficiency. This helps to enhance the coverage and signal quality of the communication system.

[0088] Improving antenna gain: By optimizing the antenna's impedance matching, you can better control the direction and intensity of the electromagnetic waves radiated by the antenna, thereby achieving a wider signal coverage range.

[0089] Improve signal stability and reduce signal distortion: Poor impedance matching may cause reflection and refraction during signal transmission, resulting in signal distortion and fluctuation. Good impedance matching can reduce these effects, improve signal stability, and make communication more reliable.

[0090] Reduced heat generation: When there is an impedance mismatch during signal transmission, reflected waves and energy loss occur, and some of this energy is converted into heat. Optimizing impedance matching can reduce this energy loss, thereby reducing heat generation.

[0091] Improve system performance and enhance the performance and stability of communication systems: Impedance matching ensures stable signal transmission within the system, avoiding signal distortion and performance degradation. This is crucial for wireless communication systems, ensuring signal coverage over a wider area.

[0092] The embodiment described above is only a preferred solution of the present invention and does not limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solution described in the claims.

Claims

1. A full-band satellite positioning antenna, characterized in that: The invention comprises an integral injection-molded shell, which comprises a top radiating surface and a bottom feeding surface. The top radiating surface comprises a first metal tuning branch for adjusting the high-frequency part of the positioning antenna and a second metal tuning branch for adjusting the low-frequency part of the positioning antenna. A parasitic unit is provided at the top corner of the top radiating surface. The top radiating surface is electromagnetically coupled to the parasitic unit, and the parasitic unit is embedded in the second metal tuning branch. A feeding probe and a metallized feeding hole are provided on the bottom feeding surface, and a feeding tuning slot is provided between the feeding probe and the metallized feeding hole.

2. The full-band satellite positioning antenna according to claim 1, characterized in that: The first metal tuning branch includes an inner concave branch and an outer epitaxial branch connected to each other, wherein the inner concave branch and the outer epitaxial branch are connected through a first branch, and the outer epitaxial branch includes an inclined branch and a second branch arranged on both sides of the inclined branch, wherein the second branch is connected to the first branch.

3. The full-band satellite positioning antenna according to claim 2, characterized in that: The second metal tuning branch includes a parasitic branch embedded with the parasitic unit and a convex branch connected to the parasitic branch. The parasitic branch and the convex branch are connected through a third branch. The convex branch is opposite to the concave branch, and a metallized feed hole is provided between the convex branch and the concave branch.

4. A full-band satellite positioning antenna according to claim 1, 2 or 3, characterized in that: The parasitic unit includes a disk structure, and coupling branches are provided at both ends of the disk structure.

5. A full-band satellite positioning antenna according to claim 1, 2 or 3, characterized in that: The bottom feeding surface is a U-shaped structure, the metallized feeding hole is arranged on the periphery of the U-shaped structure, the inner periphery of the U-shaped structure is formed into a whole with the feeding probe through metallization, four-point feeding is performed to achieve circular polarization radiation, and the feeding probe is installed inside the one-piece injection-molded shell; the feeding tuning slot is arranged between the inner periphery and the outer periphery of the U-shaped structure.

6. The full-band satellite positioning antenna according to claim 3, characterized in that: The parasitic branch includes an arc branch and fourth branches arranged at both ends of the arc branch. The fourth branch is connected to the third branch, and the angle between the two fourth branches is 90 degrees.

7. The full-band satellite positioning antenna according to claim 4, characterized in that: The one-piece injection-molded shell is a square structure with four top corners cut off. A grounding column is provided at the top corner of the bottom feeding surface. The outer side of the disc structure is metallized to form a whole with the grounding column at the corresponding position. The angle between the two coupling branches at both ends of the disc structure is 90 degrees.

8. A full-band satellite positioning antenna according to claim 1, 2, 3 or 6, characterized in that: There are four feeding probes, which are respectively arranged on the center line of each side of the integral injection-molded housing, and the four feeding probes are distributed symmetrically around the center.

9. The full-band satellite positioning antenna according to claim 5, characterized in that: Equal-amplitude excitation signals are applied to the four feeding points simultaneously, and the phase difference of the equal-amplitude excitation signals is 90 degrees.

10. The full-band satellite positioning antenna according to claim 7, characterized in that: The grounding column and the feeding probe are integrally formed by injection molding, and the top radiation surface and the bottom feeding surface are provided with through holes of the same size and opposite positions.

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