A low-profile, wide-beam, dual-frequency satellite navigation antenna for UAVs

Abstract

The present invention discloses a low-profile, wide-beam, dual-band satellite navigation antenna for unmanned aerial vehicles (UAVs). The antenna comprises an FPC dielectric substrate, a spiral radiating arm, a cover film, a top annular support, a bottom annular support, a hollow lantern-shaped support, a curved radiating arm, a base plate, and a coaxial feed. The antenna has a low profile and exhibits high gain, a wide axial ratio, and a wide half-power beamwidth within the dual-band satellite navigation system. Given its strong low-elevation-angle signal reception capability and low profile, the antenna can be used to implement UAV-mounted satellite navigation terminals with low wind resistance and high sensitivity, effectively improving the accuracy and speed of positioning for high-speed moving vehicles.

Description

Technical Field

[0001] The present invention relates to the field of satellite navigation antennas, and in particular to a low-profile, wide-beam, unmanned aerial vehicle (UAV)-mounted dual-frequency satellite navigation antenna. Background Art

[0002] With the rapid development of drone technology, it has found widespread application in a variety of fields, including military reconnaissance, civilian aerial photography, environmental monitoring, and satellite navigation. In these applications, the high-speed movements and complex environments of drones place higher demands on the accuracy and speed of satellite navigation systems. Therefore, developing low-drag, high-sensitivity navigation terminals has become a key issue in the drone industry. Antennas, as a crucial component of navigation terminals, directly determine the overall performance of the navigation system.

[0003] Traditional satellite navigation antennas are often large and have high profiles, which not only increases the wind resistance of drones but also limits their use in confined spaces or complex environments. Furthermore, due to the high speeds and large attitude variations of drones, antennas require wide beamwidths to ensure stable reception of satellite signals in all attitudes. A wide beamwidth ensures stable reception of satellite signals despite changes in the drone's attitude, which is crucial for improving the accuracy and stability of navigation systems. The low profile and wide beamwidth characteristics of drone-mounted satellite navigation antennas are crucial for improving the accuracy and speed of drone navigation systems. Since single-frequency antennas can only receive limited signal frequencies, dual-frequency and multi-frequency antennas hold great research potential. In recent years, many researchers have focused on achieving low-profile performance in drone-mounted satellite navigation antennas. However, some approaches struggle to achieve wide-beam performance due to the reduced vertical component of radiation. To address this issue, the present invention proposes a low-profile, wide-beam, drone-mounted dual-frequency satellite navigation antenna with advantages such as a wide axial ratio beam, a wide half-power beamwidth, and compactness. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention discloses a low-profile wide-beam unmanned aerial vehicle-mounted dual-frequency satellite navigation antenna, comprising: an FPC dielectric substrate, a spiral radiating arm, a cover film, a top circular ring support, a bottom circular ring support, a hollow lantern-shaped support, a curved radiating arm, a floor, and a coaxial feed;

[0005] The two sides of the FPC dielectric substrate are cylindrical and placed vertically on the upper surface of the floor, and the inner wall is tightly fitted with the top circular support and the bottom circular support;

[0006] The spiral radiating arms are tightly attached to the outer surface of the FPC dielectric substrate. There are four groups of spiral radiating arms, and each two groups are placed 90 degrees apart. Each group of spiral radiating arms includes a low-frequency spiral radiating arm, a high-frequency spiral radiating arm, a horizontal connecting metal sheet, a feeding welding point, and a short-circuit branch.

[0007] The covering film is tightly attached to the outer surface of the spiral radiation arm, effectively protecting the metal surface of the spiral radiation arm, and the top and bottom ends of the covering film are respectively located at the bottom end of the top circular support and the top end of the bottom circular support;

[0008] The outer surfaces of the top annular support and the bottom annular support are tightly fitted with the inner surface of the FPC dielectric substrate, and the top end of the top annular support is flush with the top end of the FPC dielectric substrate, and the bottom end of the bottom annular support is flush with the bottom end of the FPC dielectric substrate;

[0009] The hollow lantern-shaped support sleeve is mounted on the outer surface of the FPC dielectric substrate, and the top of the hollow lantern-shaped support is flush with the top of the FPC dielectric substrate;

[0010] There are four groups of curved radiation arms, and each two groups are etched on the surface of eight arc-shaped strips of the hollow lantern-shaped support at an interval of 90°; each group of the curved radiation arms includes a low-frequency curved radiation arm and a high-frequency curved radiation arm, the low-frequency curved radiation arm is connected to the low-frequency spiral radiation arm, and the high-frequency curved radiation arm is connected to the high-frequency spiral radiation arm.

[0011] Furthermore, by adopting top circular support and bottom circular support instead of traditional cylindrical support, the loss of the spiral radiation arm is effectively reduced; by adopting hollow lantern-shaped support, the obstruction of the spiral radiation arm is reduced, further reducing the loss of the spiral radiation arm, and significantly improving the gain of the antenna.

[0012] Furthermore, the top circular ring support, the bottom circular ring support and the hollow lantern support are all made of a low-loss medium with a loss tangent lower than 0.0006 by 3D printing, the purpose of which is to reduce the dielectric loss of the spiral radiating arm and the curved radiating arm.

[0013] Furthermore, by adopting the curved radiating arm, the cross-section of the antenna can be effectively reduced while achieving a wider half-power beamwidth; by adjusting the curvature of the curved radiating arm, the half-power beamwidth of the antenna can be adjusted.

[0014] Furthermore, by changing the lengths of the low-frequency curved radiation arm and the high-frequency curved radiation arm, the antenna can be made to resonate in different satellite navigation frequency bands.

[0015] Due to the adoption of the above technical solution, the present invention provides a low-profile wide-beam unmanned aerial vehicle dual-frequency satellite navigation antenna with the following advantages: (1) The antenna has a relatively wide 3-dB axial ratio beamwidth in the two frequency bands of satellite navigation. For example, the 3-dB axial ratio beamwidth in each direction at the 1.227 GHz frequency point reaches more than 171°; and the 3-dB axial ratio beamwidth in each direction at the 1.575 GHz frequency point reaches more than 142°. (2) The antenna has a relatively wide half-power beamwidth in the two frequency bands of satellite navigation. For example, the half-power beamwidth in each direction at the 1.227 GHz frequency point reaches more than 109°; and the half-power beamwidth in each direction at the 1.575 GHz frequency point reaches more than 106°. (3) The antenna has a relatively low profile, with a height of only 23 mm, which can effectively resist wind resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is a 3D structural diagram of a low-profile, wide-beam, UAV-mounted dual-frequency satellite navigation antenna of the present invention;

[0018] Figure 2 This is a horizontal structural exploded view of a low-profile, wide-beam, UAV-mounted dual-frequency satellite navigation antenna according to the present invention;

[0019] Figure 3 This is a 3D structural exploded view of a low-profile, wide-beam, UAV-mounted dual-frequency satellite navigation antenna of the present invention;

[0020] Figure 4 This is a structural diagram of the vertical radiation arm of a low-profile, wide-beam, UAV-mounted dual-frequency satellite navigation antenna of the present invention;

[0021] Figure 5 This is the S-parameter curve of a low-profile, wide-beam, UAV-mounted dual-frequency satellite navigation antenna of the present invention;

[0022] Figure 6 The present invention is a graph showing gain variation versus frequency for a low-profile, wide-beam, unmanned aerial vehicle (UAV)-mounted dual-frequency satellite navigation antenna.

[0023] Figure 7 This is a diagram of the axial ratio beamwidth of a low-profile, wide-beam, UAV-mounted dual-frequency satellite navigation antenna of the present invention at 1.227 GHz;

[0024] Figure 8 This is a diagram of the axial ratio beamwidth of a low-profile, wide-beam, UAV-mounted dual-frequency satellite navigation antenna of the present invention at 1.575 GHz;

[0025] Figure 9 This is a diagram of the half-power beamwidth at 1.227 GHz of a low-profile, wide-beam, UAV-mounted dual-frequency satellite navigation antenna of the present invention;

[0026] Figure 10 This is a diagram of the half-power beamwidth at 1.575 GHz of a low-profile, wide-beam, UAV-mounted dual-frequency satellite navigation antenna of the present invention;

[0027] In the figure: 1. FPC dielectric substrate, 2. Spiral radiation arm, 21. Low-frequency spiral radiation arm, 22. High-frequency spiral radiation arm, 23. Horizontal connecting metal sheet, 24. Feed welding point, 25. Short-circuit branch, 3. Cover film, 4. Top circular ring support, 5. Bottom circular ring support, 6. Hollow lantern-shaped support, 7. Curved radiation arm, 71. Low-frequency curved radiation arm, 72. High-frequency curved radiation arm, 8. Floor, 9. Coaxial feed. DETAILED DESCRIPTION

[0028] To make the technical solutions and advantages of the present invention more clear, the technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention:

[0029] like Figure 1-4 The low-profile, wide-beam, unmanned aerial vehicle (UAV)-mounted dual-frequency satellite navigation antenna shown includes: an FPC dielectric substrate 1, a spiral radiating arm 2, a covering film 3, a top circular ring support 4, a bottom circular ring support 5, a hollow lantern-shaped support 6, a curved radiating arm 7, a floor 8, and a coaxial feed 9.

[0030] The two sides of the FPC dielectric substrate 1 are cylindrical and placed vertically on the upper surface of the floor 8, and the inner wall is tightly fitted with the top circular ring support 4 and the bottom circular ring support 5; the spiral radiation arm 2 is tightly fitted on the outer surface of the FPC dielectric substrate 1, and there are 4 groups of spiral radiation arms 2, and each two groups are placed 90° apart; each group of spiral radiation arms 2 includes a low-frequency spiral radiation arm 21, a high-frequency spiral radiation arm 22, a horizontal connecting metal sheet 23, a feeding welding point 24 and a short-circuit branch 25; the covering film 3 is tightly fitted on the outer surface of the spiral radiation arm 2, effectively protecting the metal surface of the spiral radiation arm 2, and the top and bottom ends of the covering film 3 are respectively located at the bottom end of the top circular ring support 4 and the top end of the bottom circular ring support 5, and the distance is set to 2.5mm, in order to facilitate the welding of the circuit and minimize the loss as much as possible; the appearance of the top circular ring support 4 and the bottom circular ring support 5 The surfaces are tightly fitted with the inner surface of the FPC dielectric substrate 1, and the top of the top circular support 4 is flush with the top of the FPC dielectric substrate 1, and the bottom end of the bottom circular support 5 is flush with the bottom end of the FPC dielectric substrate 1; the hollow lantern-shaped support 6 is sleeved on the outer surface of the FPC dielectric substrate 1, and the top of the hollow lantern-shaped support 6 is flush with the top of the FPC dielectric substrate 1; there are 4 groups of the curved radiation arms 7, and each two groups are etched at 90° intervals on the 8 arc-shaped strip surfaces of the hollow lantern-shaped support 6; each group of the curved radiation arms 7 includes a low-frequency curved radiation arm 71 and a high-frequency curved radiation arm 72, the low-frequency curved radiation arm 71 is connected to the low-frequency spiral radiation arm 21, and the high-frequency curved radiation arm 72 is connected to the high-frequency spiral radiation arm 22; the length of the low-frequency curved radiation arm is consistent with the arc-shaped strip surface of the hollow lantern-shaped support 6, which can effectively reduce the size.

[0031] Furthermore, the use of a 0.05mm-thick FPC dielectric substrate 1 facilitates bending processing. The use of top and bottom circular supports 4 and 5, replacing traditional cylindrical supports, effectively reduces the loss of the spiral radiating arm 2. The use of a hollow lantern-shaped support 6 reduces its obstruction of the spiral radiating arm 2, further reducing the loss of the spiral radiating arm 2 and significantly improving the antenna's gain. The top, bottom, and hollow lantern-shaped supports 4, 5, and 6 are all 3D-printed from a low-loss dielectric with a loss tangent less than 0.0006 to reduce dielectric loss in the spiral radiating arm 2 and the curved radiating arm 7. The curved radiating arm 7 effectively reduces the antenna's profile while achieving a wider half-power beamwidth. Adjusting the curvature of the curved radiating arm 7 allows the antenna's half-power beamwidth to be adjusted. By varying the lengths of the low-frequency and high-frequency curved radiating arms 71 and 72, the antenna can be tuned to resonate in different satellite navigation frequency bands.

[0032] The technical indicators adopted by the present invention are as follows:

[0033] Frequency range: 1.15-1.3GHz and 1.55-1.59GHz

[0034] Polarization mode: RHCP

[0035] 3-dB axial ratio bandwidth: 1.15-1.30 GHz and 1.55-1.59 GHz

[0036] Gain: >3dBic

[0037] 3-dB axial ratio beamwidth: >120°

[0038] Half power beamwidth: >100°

[0039] Figure 5 The S parameter curve of the low-profile wide-beam unmanned aerial vehicle dual-frequency satellite navigation antenna of the present invention shows that the frequency range in which the antenna return loss is greater than 10dB is 1.08-1.41GHz (26.5%) and 1.55-1.88GHz (19.2%).

[0040] Figure 6 This graph shows the gain versus frequency for a low-profile, wide-beam, dual-frequency satellite navigation antenna for drones. The results show that the antenna achieves a gain greater than 3.5 dBic at 1.15 GHz to 1.3 GHz and greater than 5.1 dBic at 1.55 GHz to 1.59 GHz.

[0041] Figure 7 The following curves show the antenna's axial beamwidth at 1.227 GHz when phi is 0°, 45°, 90°, and 135°. The measured 3-dB axial beamwidth at 0° is 173°, at 45° is 171°, at 90° is 175°, and at 135° is 172°. This indicates that this antenna has a wide 3-dB axial beamwidth.

[0042] Figure 8 The following curves show the antenna's axial beamwidth at 1.575 GHz when phi is 0°, 45°, 90°, and 135°. The measured 3-dB axial beamwidth at 0° is 156°, at 45° is 144°, at 90° is 142°, and at 135° is 154°. This indicates that this antenna has a wide 3-dB axial beamwidth.

[0043] Figure 9The following curves show the half-power beamwidth of the antenna at 1.227 GHz when phi is 0°, 45°, 90°, and 135°. The measured half-power beamwidth at 0° is 110°, at 45° is 109°, at 90° is 112°, and at 135° is 110°. The antenna gain is 5.3 dB at 1.227 GHz. This indicates that this antenna has a wide half-power beamwidth and achieves good gain at various elevation angles.

[0044] Figure 10 The following curves show the half-power beamwidth of the antenna at 1.575 GHz when phi is 0°, 45°, 90°, and 135°. The measured half-power beamwidth at 0° is 108°, at 45° is 108°, at 90° is 106°, and at 135° is 107°. The antenna gain is 5.2 dB at 1.575 GHz. This indicates that this antenna has a wide half-power beamwidth and achieves good gain at various elevation angles.

[0045] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A low-profile wide-beam dual-frequency satellite navigation antenna for UAVs, characterized by include: FPC dielectric substrate (1), spiral radiating arm (2), covering film (3), top circular ring support (4), bottom circular ring support (5), hollow lantern support (6), curved radiating arm (7), floor (8) and coaxial feed (9); The two sides of the FPC dielectric substrate (1) are cylindrical and vertically placed on the upper surface of the floor (8), and the inner wall is tightly fitted with the top circular ring support (4) and the bottom circular ring support (5); The spiral radiation arms (2) are tightly attached to the outer surface of the FPC dielectric substrate (1); the spiral radiation arms (2) include four groups, and each two groups are placed 90 degrees apart; each group of spiral radiation arms (2) includes a low-frequency spiral radiation arm (21), a high-frequency spiral radiation arm (22), a horizontal connection metal sheet (23), a feed welding point (24), and a short-circuit branch (25); The covering film (3) is tightly attached to the outer surface of the spiral radiation arm (2) and is used to protect the metal surface of the spiral radiation arm (2), and the top and bottom ends of the covering film (3) are respectively located at the bottom end of the top circular ring support (4) and the top end of the bottom circular ring support (5); The outer surfaces of the top annular support (4) and the bottom annular support (5) are both tightly fitted with the inner surface of the FPC dielectric substrate (1), and the top end of the top annular support (4) is flush with the top end of the FPC dielectric substrate (1), and the bottom end of the bottom annular support (5) is flush with the bottom end of the FPC dielectric substrate (1); The hollow lantern-shaped support (6) is sleeved on the outer surface of the FPC dielectric substrate (1), and the top end of the hollow lantern-shaped support (6) is flush with the top end of the FPC dielectric substrate (1); The curved radiation arms (7) include four groups, and each two groups are etched on the surface of eight arc-shaped strips of the hollow lantern-shaped support (6) at a 90° interval; each group of curved radiation arms (7) includes a low-frequency curved radiation arm (71) and a high-frequency curved radiation arm (72); the low-frequency curved radiation arm (71) is connected to the low-frequency spiral radiation arm (21), and the high-frequency curved radiation arm (72) is connected to the high-frequency spiral radiation arm (22).

2. The low-profile, wide-beam, dual-frequency satellite navigation antenna for unmanned aerial vehicles according to claim 1, characterized in that: The top circular ring-shaped support (4), the bottom circular ring-shaped support (5), and the hollow lantern-shaped support (6) are all made of a low-loss medium with a loss tangent lower than 0.0006 and are manufactured by 3D printing, thereby reducing the dielectric loss of the spiral radiation arm (2) and the curved radiation arm (7).

3. The low-profile, wide-beam, dual-frequency satellite navigation antenna for unmanned aerial vehicles according to claim 1, characterized in that: The curved radiating arm (7) effectively reduces the cross-section of the antenna while achieving a wider half-power beam width; the half-power beam width of the antenna is adjusted by adjusting the curvature of the curved radiating arm (7).

4. The low-profile, wide-beam, dual-frequency satellite navigation antenna for unmanned aerial vehicles according to claim 1, characterized in that: By changing the lengths of the low-frequency curved radiation arm (71) and the high-frequency curved radiation arm (72), the antenna is controlled to resonate in different satellite navigation frequency bands.

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