Low-profile circularly polarized antenna covered by axial-ratio beam of front hemisphere

Abstract

The utility model discloses a low-profile circularly polarized antenna covered by a front hemisphere axial ratio wave beam. The low-profile circularly polarized antenna comprises a first dielectric substrate, a microstrip radiation patch, a metal floor, a metalized through hole and a feed probe, a microstrip radiation patch is printed on the upper surface of the first dielectric substrate, and a metal floor is arranged on the lower surface; a metalized through hole is formed in the first dielectric substrate; the microstrip radiation patch is provided with a notch annular gap, a rectangular gap subjected to circular arc processing and a corner cut structure subjected to circular arc processing; a round hole for the feed probe to pass through is etched on the metal floor; the feed probe passes through the first dielectric substrate and is connected with the center of the microstrip radiation patch. According to the utility model, the wide axial ratio wave beam performance is realized, the axial ratio wave beam coverage of the front hemisphere is further realized, and in addition, the antenna also has the advantages of low profile, simple structure and the like.

Description

Technical Field

[0001] This utility model relates to the technical field of communication antennas, and in particular to a low-profile circularly polarized antenna with front hemispherical axial ratio beam coverage. Background Technology

[0002] Antennas are core components for electromagnetic wave transmission and reception, playing a crucial role in wireless communication systems. The design and performance of antennas directly affect the coverage, transmission quality, and efficiency of wireless communication systems. Compared to linearly polarized antennas, circularly polarized antennas offer advantages such as resistance to multipath interference, resistance to polarization mismatch, strong anti-interference capabilities, and good dynamic adaptability. These characteristics have led to the widespread application of circularly polarized antennas in satellite communications, navigation and positioning, unmanned aerial vehicles (UAVs), and mobile communications.

[0003] For Global Navigation Satellite Systems (GNSS), satellite locations are sometimes dispersed. To ensure that a circularly polarized antenna can receive signals from multiple navigation satellites for accurate positioning, the receiver antenna must have the widest possible axial ratio beamwidth and receive signals over the widest possible spatial range. In engineering applications, a low-profile design facilitates antenna integration with the surrounding structure and also helps reduce wind resistance or mechanical complexity caused by increased installation height. Based on these considerations, a low-profile circularly polarized antenna with wide axial ratio beamwidth and hemispherical spatial coverage has been designed, which has high application value in global navigation satellite systems.

[0004] However, regarding the publicly disclosed technologies and structures for low-profile circularly polarized antennas with hemispherical axial ratio beam coverage, the following issues still exist.

[0005] 1. Circularly polarized antennas with wide axial ratio beams only achieve wide axial ratio beam performance in 1 to 2 planes, failing to widen the axial ratio beamwidth in other planes, which limits the spatial range of signals transmitted and received by circularly polarized antennas.

[0006] 2. Circularly polarized antennas with hemispherical axial ratio beam coverage often employ a distributed feed method, which usually results in a more complex structure, larger volume, and higher profile. Utility Model Content

[0007] The purpose of this invention is to overcome the shortcomings and deficiencies of the prior art and provide a low-profile circularly polarized antenna with front hemisphere axial ratio beam coverage. While achieving wide axial ratio beam performance, it further realizes front hemisphere axial ratio beam coverage. In addition, it also has the characteristics of low profile and simple structure.

[0008] To achieve the above objectives, the technical solution provided by this utility model is as follows: a low-profile circularly polarized antenna with hemispherical axial ratio beam coverage, comprising a dielectric substrate, a microstrip radiating patch, a metal ground plane, metallized vias, and a feed probe; the microstrip radiating patch is printed on the upper surface of the dielectric substrate; metallized vias are provided inside the dielectric substrate; a metal ground plane is provided on the lower surface of the dielectric substrate; the microstrip radiating patch is a square patch with a concentric annular notch at its center, and a rectangular slit with rounded ends at the center of each side, the rectangular slits on two parallel sides are symmetrically distributed about the central axis of the microstrip radiating patch, and the rectangular slits on adjacent sides are of different lengths, the circular polarization performance of the antenna can be optimized by adjusting the length of the rectangular slits; the four corners of the microstrip radiating patch are rounded chamfered structures; a circular hole for the feed probe to pass through is etched on the metal ground plane; the feed probe passes through the dielectric substrate and connects to the center of the microstrip radiating patch, exciting the microstrip radiating patch to radiate signals by coaxial feeding.

[0009] The width of the annular gap is greater than 0.1 mm, and the gap is located at the +45° diagonal of the microstrip radiating patch.

[0010] Preferably, the four chamfered corners of the microstrip radiating patch are identical.

[0011] Preferably, the metallized vias are arranged around the microstrip radiating patch to form a group of metallized vias surrounding the microstrip radiating patch. The group of metallized vias is symmetrically distributed about the -45° diagonal of the microstrip radiating patch, and two of the diagonal positions of the group of metallized vias are recessed.

[0012] Preferably, the dielectric substrate is a square substrate and is on the same diagonal as the microstrip radiating patch.

[0013] Preferably, the dielectric substrate is an FR4 substrate.

[0014] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0015] 1. This utility model is a single-layer antenna structure with low structural complexity and a cross-sectional height of only 0.026λ0 (λ0 is the wavelength corresponding to the center frequency of the antenna).

[0016] 2. This utility model achieves wide axis ratio beam performance, with the widest beam reaching 193°.

[0017] 3. This invention achieves axial ratio beam coverage in the front hemisphere. By designing the microstrip patch structure and loading a recessed metallized via group, the antenna's axial ratio and gain performance are well balanced within the front hemisphere space.

[0018] 4. The dielectric substrate of this utility model is made of FR4 material, which has a very low manufacturing cost and high cost performance.

[0019] 5. This utility model adopts a central coaxial power supply, which is beneficial for impedance matching and reducing interference. Attached Figure Description

[0020] Figure 1 This is a top view of a low-profile circularly polarized antenna.

[0021] Figure 2 This is a side view of a low-profile circularly polarized antenna.

[0022] Figure 3 This is a graph showing the S-parameter test results of a low-profile circularly polarized antenna.

[0023] Figure 4 This is a graph showing the test results of the axial ratio and gain of a low-profile circularly polarized antenna in the 1.5-1.64 GHz range along the maximum radiation direction (i.e., phi = 0°, theta = 0°).

[0024] Figure 5 This is a graph showing the axial ratio and gain test results of a low-profile circularly polarized antenna at 1.56 GHz in the plane with phi = 0°.

[0025] Figure 6 This is a graph showing the axial ratio and gain test results of a low-profile circularly polarized antenna at 1.56 GHz in the plane with phi = 45°.

[0026] Figure 7 This is a graph showing the axial ratio and gain test results of a low-profile circularly polarized antenna at 1.56 GHz in the plane with phi = 90°.

[0027] Figure 8 This is a graph showing the axial ratio and gain test results of a low-profile circularly polarized antenna at 1.56 GHz in the plane with phi = 135°. Detailed Implementation

[0028] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the implementation of the present invention is not limited thereto.

[0029] like Figure 1 and Figure 2As shown, this embodiment discloses a low-profile circularly polarized antenna with hemispherical axial ratio beam coverage, including a dielectric substrate 1, a microstrip radiating patch 2, a metal ground plane 3, a metallized via 4, and a feed probe 5. The microstrip radiating patch 2 is printed on the upper surface of the dielectric substrate 1; the metal ground plane 3 is disposed on the lower surface of the dielectric substrate 1; the microstrip radiating patch 2 is a square patch with a concentric annular notch 21 at its center, the width of which is greater than 0.1 mm, and the notch is located at the +45° diagonal of the microstrip radiating patch 2. A rectangular slit 22 with rounded ends is formed at the center of each side of the microstrip radiating patch 2. The rectangular slits 22 on two parallel sides are symmetrically distributed about the central axis of the microstrip radiating patch 2, and adjacent to each other... The rectangular slots 22 on the two sides are of different lengths. By adjusting the length of the rectangular slots 22, the circular polarization performance of the antenna can be optimized. The four corners of the microstrip radiating patch 2 are all identical chamfered structures 23 with rounded edges. The dielectric substrate 1 has metallized vias 4 inside. The metallized vias 4 are arranged around the microstrip radiating patch 2 to form a group of metallized vias surrounding the microstrip radiating patch 2. The group of metallized vias is symmetrically distributed about the -45° diagonal of the microstrip radiating patch 2. Two of the diagonal positions of the group of metallized vias are recessed. The metal ground plate 3 has a circular hole etched on it for the feed probe 5 to pass through. The feed probe 5 passes through the dielectric substrate 1 and connects to the center of the microstrip radiating patch 2, so as to excite the microstrip radiating patch 2 to radiate by coaxial feeding.

[0030] Specifically, the first dielectric substrate 1 is a square substrate, sharing the same diagonal as the microstrip radiating patch 2. It has a length and width of 80 mm and a thickness of 4.8 mm. It is made of FR4 material with a dielectric constant of 4.4 and a loss tangent of 0.02. The microstrip radiating patch 2 has a length and width of 41 mm. The notched annular slot 21 has a width and radius of 0.3 mm and 8 mm, respectively. The rounded rectangular slots 22 have lengths of 7.5 mm and 3.6 mm, and a width of 1.3 mm. The rounded chamfered structure 23 has a radius of 7 mm. The metallized vias 4 have a radius and spacing of 1.5 mm and 5 mm, respectively.

[0031] like Figure 3 As shown, the test S-parameters of the low-profile circularly polarized antenna described above in this embodiment are given, with a -10dB impedance bandwidth of 7.64% (1.51GHz-1.63GHz).

[0032] like Figure 4As shown, the test performance of the low-profile circularly polarized antenna described in this embodiment is presented in the axial ratio and gain range of 1.5-1.64 GHz in the maximum radiation direction (i.e., phi = 0°, theta = 0°). The 3dB axial ratio bandwidth test value is 1.28% (1.55GHz-1.57GHz). The normal gain at 1.56GHz is 3.8dB.

[0033] like Figure 5 As shown, the test performance of the low-profile circularly polarized antenna described in this embodiment at 1.56 GHz, with phi = 0° in-plane axial ratio and gain, is given. The 3dB axial ratio beamwidth is 216° and the half-power beamwidth is 102°.

[0034] like Figure 6 As shown, the test performance of the low-profile circularly polarized antenna described in this embodiment at 1.56 GHz, with phi = 45° in-plane axial ratio and gain, is given. The 3dB axial ratio beamwidth is 215° and the half-power beamwidth is 101°.

[0035] like Figure 7 As shown, the test performance of the low-profile circularly polarized antenna described in this embodiment at 1.56 GHz, with phi = 90° in-plane axial ratio and gain, is given. The 3dB axial ratio beamwidth is 216° and the half-power beamwidth is 105°.

[0036] like Figure 8 As shown, the test performance of the low-profile circularly polarized antenna described in this embodiment at 1.56 GHz, with an in-plane axial ratio and gain of phi = 135°, is given. The 3dB axial ratio beamwidth is 196° and the half-power beamwidth is 102°.

[0037] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A low profile circularly polarized antenna with front hemi-sphere axial ratio beam coverage, characterized in that, The application relates to a circularly polarized antenna, which comprises a medium substrate (1), a microstrip radiation patch (2), a metal floor (3), a metalized via (4) and a feed probe (5); the upper surface of the medium substrate (1) is printed with the microstrip radiation patch (2); the medium substrate (1) is internally provided with the metalized via (4); the lower surface of the medium substrate (1) is provided with the metal floor (3); the microstrip radiation patch (2) is a square patch, the center part of which is provided with a concentric notch ring gap (21), and the center of each side is provided with a rectangular gap (22) with a rounded end, the rectangular gaps (22) on the two parallel sides are symmetrically distributed about the central axis of the microstrip radiation patch (2), and the rectangular gaps (22) on the adjacent two sides are of different lengths; the circular polarization performance of the antenna can be optimized by adjusting the length of the rectangular gap (22); the four corners of the microstrip radiation patch (2) are rounded corner structures (23); the metal floor (3) is etched with a circular hole for the feed probe (5) to pass through; the feed probe (5) is connected with the center of the microstrip radiation patch (2) through the medium substrate (1) and excites the microstrip radiation patch (2) to radiate in a coaxial line feed mode.

2. The low-profile circularly polarized antenna of front-hemisphere axial ratio beam coverage according to claim 1, characterized in that, The width of the notch ring gap (21) is greater than 0.1 mm, and the position of the notch is located at the +45-degree diagonal line of the microstrip radiation patch (2).

3. The low-profile circularly polarized antenna of front-hemisphere axial ratio beam coverage according to claim 2, characterized in that, The four corner structures (23) of the microstrip radiation patch (2) are completely the same.

4. The low-profile circularly polarized antenna of front-hemisphere axial ratio beam coverage according to claim 3, characterized in that, The metalized via (4) is arranged around the microstrip radiation patch (2) to form a metalized via group surrounding the microstrip radiation patch (2), the metalized via group is symmetrically distributed about the -45-degree diagonal line of the microstrip radiation patch (2), and two diagonal positions of the metalized via group are designed to be inwardly recessed.

5. The low-profile circularly polarized antenna of front-hemisphere axial ratio beam coverage according to claim 4, characterized in that, The medium substrate (1) is a square substrate and is located on the same diagonal line as the microstrip radiation patch (2).

6. The low-profile circularly polarized antenna of front-hemisphere axial ratio beam coverage according to claim 5, wherein, The medium substrate (1) is an FR4 substrate.

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