Lightweight isometric high-gain circularly polarized patch antenna array and design method thereof

Abstract

The application discloses a lightweight isomerism high-gain circularly polarized patch antenna array and a design method thereof, and belongs to the technical field of wireless communication antennas. The antenna array comprises a floor, a first and a second fan-shaped patch arranged above the floor, and a feed network arranged below the floor. The central angle of the first fan-shaped patch is smaller than that of the second fan-shaped patch. Air medium two and medium one are arranged between the first fan-shaped patch and the floor, and air medium two and medium three are arranged between the second fan-shaped patch and the floor. The relative dielectric constant of the medium one is greater than that of the medium three. The two fan-shaped patches are orthogonally distributed by rotating 90 degrees around the central axis of the antenna. The feed network provides excitation signals with a phase difference of 90 degrees for the two fan-shaped patches. The application compensates the physical size of the isomerism patch by using the dielectric constant difference, combines the air layer and the sequential rotation feed mechanism, and realizes smooth high gain and excellent circularly polarized radiation characteristics under the premise of low profile and light weight.

Description

Technical Field

[0001] This invention belongs to the field of wireless communication antenna technology, specifically relating to a lightweight heterogeneous high-gain circularly polarized patch antenna array and its design method. Background Technology

[0002] With the rapid development of counter-drone technology, its applications in aerial photography, surveying, and low-altitude logistics are becoming increasingly widespread. 5.8GHz is the core frequency band for high-definition image transmission and control links for drones. However, existing airborne antennas struggle to balance physical shape and radiation performance. Traditional omnidirectional or low-gain airborne antennas have limited radiation distances, making it difficult to meet the requirements for long-range image transmission; while traditional high-gain directional antennas are bulky and have excessively high profiles, significantly increasing the drone's weight and disrupting its aerodynamic characteristics, severely impacting flight stability and endurance. While conventional microstrip antennas can reduce the profile, they are limited by surface wave interference and dielectric loss, resulting in severe in-band gain fluctuations.

[0003] Therefore, how to maintain miniaturization, lightweight design, and low profile while providing stable high gain in the 5.8GHz band for anti-drone applications is an engineering bottleneck that urgently needs to be addressed in the field of anti-drone front-end antennas. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a lightweight heterogeneous high-gain circularly polarized patch antenna array and its design method, thereby solving the problems in the prior art.

[0005] The objective of this invention can be achieved through the following technical solutions: A circularly polarized patch antenna array, comprising: floor; A first sector-shaped patch and a second sector-shaped patch are disposed above the floor. The central angle of the first sector-shaped patch is smaller than that of the second sector-shaped patch. The second sector-shaped patch is orthogonally distributed relative to the first sector-shaped patch, rotated 90° around the central axis of the antenna. A power supply network is disposed below the floor; the power supply network is connected to the first sector patch and the second sector patch respectively, and the power supply network provides excitation signals with a 90° phase difference to the first sector patch and the second sector patch respectively according to the input radio frequency signal; Wherein, a first dielectric layer is provided between the first sector patch and the floor, the first dielectric layer including a dielectric one located above and an air dielectric two located below and adjacent to the floor; a second dielectric layer is provided between the second sector patch and the floor, the second dielectric layer including a dielectric three located above and the air dielectric two located below and adjacent to the floor; the relative permittivity of the dielectric one is greater than the relative permittivity of the dielectric three; Furthermore, the central angles of both the first and second sector patches are between 180° and 350°, and the difference between the central angle of the second sector patch and the central angle of the first sector patch is greater than 15°.

[0006] Furthermore, the antenna array also includes metal short-circuit pins, which are respectively connected between the first sector patch and the ground plane, and between the second sector patch and the ground plane, serving as a mechanical support structure for the first sector patch and the second sector patch to be suspended above the second air medium.

[0007] Furthermore, the feeding network includes a T-type microstrip power divider network with a 1-to-2 split and a microstrip delay line. The electrical length of the microstrip delay line is one-quarter of the wavelength of the antenna's operating center frequency. The phase of the input signal is configured through the microstrip delay line. The power supply network is configured such that the signal input to the first sector patch lags behind the signal of the second sector patch by 90° phase to form left-hand circularly polarized radiation; or, the signal input to the first sector patch leads the signal of the second sector patch by 90° phase to form right-hand circularly polarized radiation.

[0008] Furthermore, the power supply network is connected to the first sector patch and the second sector patch via different coaxial probes passing through the floor and the second air medium, respectively.

[0009] Furthermore, the height of the second sector-shaped patch from the floor is not less than the height of the first sector-shaped patch from the floor.

[0010] Furthermore, the height difference between the first sector patch and the second sector patch is no greater than 0.015 times the free space wavelength corresponding to the antenna's operating center frequency.

[0011] Furthermore, the overall profile height of the antenna array is no greater than 0.07 times the free space wavelength corresponding to the antenna's operating center frequency.

[0012] Furthermore, the center-to-center distance between the first sector patch and the second sector patch is 0.7-1 times the free space wavelength corresponding to the working center frequency.

[0013] The above-described design method for a circularly polarized patch antenna array includes the following steps: Construct a floor and a power supply network located beneath the floor; Above the floor, a first sector patch and a second sector patch with different central angles are arranged such that the second sector patch with a larger central angle is orthogonally distributed relative to the first sector patch with a smaller central angle, rotated 90° around the antenna central axis. A first medium layer comprising medium one and air medium two is disposed between the first sector patch and the floor, and a second medium layer comprising medium three and air medium two is disposed between the second sector patch and the floor; Based on the difference in the central angle between the first sector patch and the second sector patch, the relative permittivity of the first dielectric is set to be greater than that of the third dielectric, so as to reduce the physical size difference between sector patches with different central angles. The power supply network is configured to pass through the floor and the air medium, respectively connecting to the first sector patch and the second sector patch, and based on the one-to-two power splitting structure and quarter-wavelength delay line, to provide radio frequency signals with a 90° phase difference to the first sector patch and the second sector patch.

[0014] The beneficial effects of this invention are: 1. This invention employs a layered suspended microstrip structure beneath the radiating patch, introducing an air dielectric layer and controlling the overall profile height of the antenna to be no greater than 0.07 times the free-space wavelength of the operating center frequency. By replacing most of the solid dielectric substrate with an air layer (presumably, replacing most of the air layer with a solid dielectric substrate), this structure effectively reduces the antenna's equivalent dielectric constant, thereby reducing dielectric loss and surface wave interference. Simulation results show that the antenna gain remains stably above 8.6 dBi (left-handed) or 9.3 dBi (right-handed) within the operating frequency band. This design effectively suppresses gain fluctuations in conventional microstrip antennas while maintaining lightweight and low profile characteristics, avoiding negative impacts on the stability and endurance of UAV flight (used in anti-UAV applications).

[0015] 2. This invention employs a first sector patch (smaller) and a second sector patch (larger) with different central angles to construct a heterogeneous radiating layer. To balance the two, the relative permittivity of dielectric material one beneath the first sector patch is limited to be greater than that of dielectric material three beneath the second sector patch (in this embodiment, dielectric material one is FR4 with a relative permittivity of 4.4, and dielectric material three is air). Materials with higher permittivity produce a slow-wave effect; based on this principle, dielectric material one increases the electrical length of the first sector patch with the smaller central angle, compensating for the resonance shift caused by its smaller physical area. This synergistic design of material properties and physical shape successfully reduces the physical size difference between sector patch antennas with different central angles, which is beneficial for the compact layout of the array and the miniaturization of the overall antenna.

[0016] 3. This invention employs sequential rotation feeding technology, rotating the second sector patch 90° relative to the first sector patch around the central axis to achieve an axisymmetric distribution. Simultaneously, the underlying feeding network, based on a quarter-wavelength microstrip delay line, provides the two patches with the same power and a 90° phase difference. The combination of this spatially orthogonal 90° arrangement and the 90° phase difference in the feeding signal effectively generates circularly polarized waves. According to the test curves of the embodiment, this heterogeneous and sequentially rotating design allows the antenna to maintain good impedance matching across a wide frequency band, from 5.42GHz to 6.35GHz (left-handed rotation), and its axial ratio of less than 3dB successfully covers the core 5.8GHz operating frequency band for anti-drone systems, ensuring anti-interference capabilities in complex communication links.

[0017] 4. In the suspended microstrip structure of the present invention, the conductive support uses metal short-circuit pins to connect the first and second sector patches to the underlying ground plane respectively; and the bottom energy distribution uses a simple one-to-two T-type microstrip power divider network; since the air layer lacks solid support, large-area thin film patches are prone to deformation or collapse; the introduction of metal short-circuit pins not only provides the necessary mechanical support rigidity and ensures the structural stability of the suspended air layer thickness (metal short-circuit pins also have the function of adjusting impedance matching and suppressing unwanted modes), but also, in conjunction with the simple one-to-two microstrip power divider network, significantly reduces the difficulty of processing and assembly and manufacturing costs, and improves the practicality of the antenna in engineering mass production. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the three-dimensional structure and reference coordinates of the lightweight heterogeneous high-gain circularly polarized patch antenna array of the present invention; Figure 2 This is a schematic diagram of the bottom feeding structure and reference coordinates of the lightweight heterogeneous high-gain circularly polarized patch antenna array of the present invention; Figure 3 This invention uses HFSS software to calculate the reflection coefficient characteristics of a lightweight heterogeneous high-gain circularly polarized patch antenna array. Figure 4 This is a diagram showing the axial ratio characteristics of a lightweight heterogeneous high-gain circularly polarized patch antenna array calculated using HFSS software in this invention. Figure 5 This is a gain characteristic diagram of a lightweight heterogeneous high-gain circularly polarized patch antenna array calculated using HFSS software in this invention; Figure 6 Example 2 shows the reflection coefficient characteristics of a lightweight heterogeneous high-gain circularly polarized patch antenna array calculated using HFSS software. Figure 7 This is the axial ratio characteristic diagram of the lightweight heterogeneous high-gain circularly polarized patch antenna array calculated using HFSS software in Example 2; Figure 8 This is the gain characteristic diagram of the lightweight heterogeneous high-gain circularly polarized patch antenna array calculated using HFSS software in Example 2; In the diagram: 1-floor, 2-first sector patch, 3-second sector patch, 4-dielectric one, 5-dielectric two, 6-dielectric three, 7-first coaxial probe, 7'-second coaxial probe, 8-first short-circuit pin, 8'-second short-circuit pin, 9-power supply network. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1 This embodiment proposes a lightweight, heterogeneous, high-gain circularly polarized patch antenna array, such as... Figure 1 what Figure 2 As shown, it includes: a floor 1, a first short-circuit pin 8, a second short-circuit pin 8', a first coaxial probe 7, a second coaxial probe 7', and a power supply network 9 loaded below the floor 1; Above the floor 1, a first sector-shaped patch 2 with a smaller central angle and a second sector-shaped patch 3 with a larger central angle are arranged. The dielectric layer below the first sector-shaped patch 2 adopts a suspended microstrip structure, that is, the dielectric layer below the radiating patch (first sector-shaped patch 2) is divided into upper and lower layers. The upper layer is dielectric 4 printed with the radiating patch, and the lower layer is air dielectric 5. The dielectric layer below the second sector-shaped patch 3 also adopts a suspended microstrip structure. The dielectric layer below the radiating patch (second sector-shaped patch 3) is divided into upper and lower layers. The upper layer is dielectric 6, and the lower layer is air dielectric 5. Among them, the relative permittivity of the upper dielectric 4 of the first sector-shaped patch 2 needs to be greater than that of the upper dielectric 6 of the suspended microstrip structure of the second sector-shaped patch 3.

[0022] Using sequential rotational feeding technology, the second sector patch 3 is symmetrically distributed around the antenna central axis with a 90° rotation axis relative to the first sector patch 2. The feeding network 9 is connected to the first sector patch 2 and the second sector patch 3 through the first coaxial probe 7 and the second coaxial probe 7', respectively (the coaxial probes 7 and 7' are 6.6 mm and 9.1 mm away from the center of their respective sector patches, respectively, both on the axis of symmetry of the patches). At the same time, the underlying feeding network uses a microstrip delay line with an electrical length of one-quarter wavelength to feed in a 90° phase difference radio frequency signal. When the signal input to the first sector patch 2 lags behind the signal input to the second sector patch 3 by 90° phase, left-hand circular polarization is achieved; when the signal input to the first sector patch 2 leads the signal input to the second sector patch 3 by 90° phase, right-hand circular polarization is achieved.

[0023] The first short-circuit pin 8 and the second short-circuit pin 8' serve as mechanical support structures for the first sector patch 2 and the second sector patch 3 to be suspended above the medium 5, respectively (the metal short-circuit pin is placed at the center and the pin diameter is 3mm).

[0024] In some embodiments, the central angles of the first sector patch 2 and the second sector patch 3 range from 180° to 350°, and the difference in central angle between the second sector patch 3 (with a larger central angle) and the first sector patch 2 (with a smaller central angle) is greater than 15°. The overall profile height of the antenna is not greater than 0.07 times the free-space wavelength of the antenna's operating center frequency. The height of the second sector patch 3 is not less than the height of the first sector patch 2, and the height difference is not greater than 0.015 times the free-space wavelength corresponding to the antenna's operating center frequency.

[0025] The power supply network 9 can use any common power divider structure for energy distribution; in this embodiment, a 1-to-2 T-type microstrip power divider network is specifically used, which consists of two patch units, already tuned to 50 ohms, and then spliced ​​together. The specific linewidth (used to control the characteristic impedance) of the power supply network is 1.5mm, and the line length (quarter-wavelength impedance converter) is 7.3mm.

[0026] In this embodiment, the ground plane 1 uses an FR4 dielectric substrate with a thickness of 0.8 mm; the first sector patch 2 has a central angle of 240° and adopts a suspended microstrip structure, meaning the dielectric layer below the radiating patch is divided into upper and lower layers. The upper dielectric 4 is an FR4 dielectric substrate with a height of 0.5 mm and a relative permittivity of 4.4, and the lower layer is an air dielectric with a height of 1.66 mm; the second sector patch 3 has a central angle of 300° (the arc length of the sector is 1.5 times the wavelength, calculated according to the sector formula), and adopts a suspended microstrip structure. The dielectric layer below the radiating patch is divided into upper and lower layers, and the upper dielectric 6 is also an air dielectric. Therefore, the layer below the second sector patch 3 is a pure air layer with a thickness of 2.84 mm. The height of the second sector patch 3 is greater than the height of the first sector patch 2, and the longitudinal height difference between the two is 0.68 mm. The overall cross-sectional height of the antenna is only 3.64 mm.

[0027] Example 2 In this embodiment, the antenna parameters can also be set as follows: the ground plane 1 uses an FR4 dielectric substrate with a thickness of 0.8mm; the central angle of the first sector patch 2 is 255°, and a suspended microstrip structure is adopted, that is, the dielectric layer below the radiating patch is divided into upper and lower layers. The upper dielectric 4 is an FR4 dielectric substrate with a height of 0.5mm and a relative permittivity of 4.4, and the lower layer is an air dielectric with a height of 1.7mm; the central angle of the second sector patch 3 is 300°, and a suspended microstrip structure is adopted. The dielectric layer below the radiating patch is divided into upper and lower layers. The upper dielectric 6 is also an air dielectric. Therefore, the layer below the second sector patch 3 is a pure air layer with a thickness of 2.84mm. The height of the second sector patch 3 is greater than the height of the first sector patch 2, and the longitudinal height difference between the two is 0.64mm. The overall cross-sectional height of the antenna is only 3.64mm.

[0028] Example 3 In this embodiment, the characteristics of the antennas proposed in Embodiments 1 and 2 are simulated and calculated using HFSS software; the specific simulation modeling steps are as follows: Step 1: Establish the antenna's geometric and physical model and assign material properties; The 3D structure of the antenna is constructed in the software. A 0.8mm thick FR4 dielectric substrate is built as the antenna's ground plane. A heterogeneous suspended microstrip structure is constructed above this ground plane: for the first sector patch with a central angle of 240°, two dielectric layers are constructed below it. The upper layer is an FR4 dielectric substrate with a height of 0.5mm and a relative permittivity of 4.4 (i.e., dielectric one), and the lower layer is an air layer with a height of 1.66mm (i.e., dielectric two). For the second sector patch with a central angle of 300°, a pure air layer is constructed below it (i.e., both the upper dielectric three and the lower dielectric two are air), with a total thickness of 2.84mm. In the modeling parameter constraints, the height of the second sector patch is set to be greater than that of the first sector patch, and the longitudinal height difference between the two is precisely set to 0.68mm, thereby ensuring that the overall cross-sectional height of the antenna is only 3.64mm. Meanwhile, a physical model of the metal short-circuit pin was established based on the structure, and the material properties of the radiating patch, the ground plane, and the short-circuit pin were set as ideal conductors or metallic copper.

[0029] Step 2: Construct the power supply network and excitation port; A T-shaped microstrip power divider network model is constructed on the bottom layer of the ground plane. The physical dimensions of the microstrip line are adjusted according to the antenna's center operating frequency, making it equivalent to a microstrip delay line with an electrical length of one-quarter wavelength, thereby achieving a 90° phase difference RF signal. The input signal is configured according to the antenna's polarization requirements: when configuring left-hand circular polarization, the signal input to the first sector patch is set to lag behind the signal input to the second sector patch by 90° phase; when configuring right-hand circular polarization, the signal input to the first sector patch is set to lead by 90° phase. An excitation port with a characteristic impedance of 50 ohms is set at the input of the power divider network.

[0030] Step 3: Set radiation boundary conditions and mesh generation; A vacuum air cavity is built outside the antenna array model, surrounding the entire physical structure. Each surface of the air cavity is set to be at least one-quarter of the operating wavelength from the antenna radiator, and the boundary conditions of the outer surface of the air cavity are defined as radiation boundaries to simulate the electromagnetic wave radiation environment in free space.

[0031] Step 4: Set the solution frequency and sweep frequency parameters; Add electromagnetic field solver settings. Set the center solver frequency to the core band of the anti-drone band, 5.8 GHz, to optimize the mesh generation near this frequency. For complete coverage... Figures 3 to 5 To improve the data range, a frequency sweep setting was added, with the sweep interval set to 5.0GHz to 7.0GHz and the sweep step size set to 0.01GHz, to ensure that the extracted resonance curve and axial ratio curve have high-precision smoothness.

[0032] Step 5: Run the solution and extract post-processed data Run the HFSS solver to perform the calculation. After the calculation converges, extract the corresponding curve data in the post-processing module.

[0033] Figure 3 The simulation curve of the reflection coefficient of this lightweight heterogeneous high-gain circularly polarized patch antenna array as a function of frequency was calculated using HFSS software.

[0034] Depend on Figure 3 It can be seen that under the standard condition of a reflectance coefficient less than -10dB, Figure 3 (a) shows that the antenna proposed in Example 1 successfully covers the impedance operating bandwidth from 5.42 GHz to 6.35 GHz in the case of left-hand circular polarization. Figure 3 (b) in Example 1 demonstrates that the antenna proposed in Example 1 successfully covers the impedance operating bandwidth from 5.37 GHz to 6.47 GHz in right-hand circular polarization, exhibiting excellent broadband impedance matching characteristics.

[0035] Figure 4 The figure shows the simulation curve of the axial ratio of the lightweight heterogeneous high-gain circularly polarized patch antenna array as a function of frequency, calculated using HFSS software.

[0036] in, Figure 4 (a) shows that the antenna proposed in Example 1, in the case of left-hand circular polarization, meets the standard circular polarization criterion of axial ratio less than 3dB in the frequency band from 5.72GHz to 5.93GHz. Figure 4 (b) shows that the antenna proposed in Example 1, in the case of right-hand circular polarization, meets the standard circular polarization criterion of axial ratio less than 3dB in the frequency band from 5.69GHz to 5.91GHz, covering the anti-drone 5.8GHz frequency band.

[0037] Figure 5 The curve shows the response curve of the radiation gain of this lightweight heterogeneous high-gain circularly polarized patch antenna array as a function of frequency, calculated using HFSS software.

[0038] Figure 5 (a) shows the antenna curves proposed in Example 1 under left-hand circular polarization. In the operating frequency band from 5.57 GHz to 5.88 GHz, the antenna gain is stably maintained above 8.6 dBi, and the peak gain of 8.7 dBi is reached at 5.76 GHz. Figure 5 Figure (b) shows the antenna curves proposed in Example 1 under right-hand circular polarization. In the operating frequency band from 5.56 GHz to 5.88 GHz, the antenna gain is stably maintained above 9.3 dBi, and the peak gain of 9.5 dBi is reached at 5.68 GHz. This proves that the design method of this lightweight heterogeneous high-gain circularly polarized patch antenna array can achieve stable high-gain characteristics in the operating frequency band of UAVs.

[0039] Figure 6 Example 2 shows the reflection coefficient characteristics of a lightweight heterogeneous high-gain circularly polarized patch antenna array calculated using HFSS software. Depend on Figure 6 It can be seen that under the standard condition of a reflectance coefficient less than -10dB, Figure 6 (a) shows that the antenna proposed in Example 2 (first patch central angle 255°) successfully covers the impedance operating bandwidth of 5.26 GHz to 6.35 GHz in left-hand circular polarization. Figure 6 (b) in Example 2 demonstrates that the antenna proposed in Example 2 successfully covers the impedance operating bandwidth from 5.37 GHz to 6.47 GHz in the right-hand circular polarization case, exhibiting excellent broadband impedance matching characteristics.

[0040] Figure 7 This is the axial ratio characteristic diagram of the lightweight heterogeneous high-gain circularly polarized patch antenna array calculated using HFSS software in Example 2; middle, Figure 7 (a) shows that the antenna proposed in Example 2 meets the standard circular polarization criterion of axial ratio less than 3dB in the frequency band from 5.70GHz to 5.88GHz under left-hand circular polarization. Figure 7 (b) shows that the antenna proposed in Example 2, in the case of right-hand circular polarization, meets the standard circular polarization criterion of axial ratio less than 3dB in the frequency band from 5.65GHz to 5.87GHz, covering the anti-drone 5.8GHz frequency band.

[0041] Figure 8 This is the gain characteristic diagram of the lightweight heterogeneous high-gain circularly polarized patch antenna array calculated using HFSS software in Example 2; Figure 8 (a) shows the antenna curve proposed in Example 2 under left-hand circular polarization. In the operating frequency band from 5.46 GHz to 5.85 GHz, the antenna gain is stably maintained above 8.6 dBi, and the peak gain of 8.7 dBi is reached at 5.58 GHz. Figure 7 Figure (b) shows the antenna curve proposed in Example 2 under right-hand circular polarization. In the operating frequency band from 5.46 GHz to 5.85 GHz, the antenna gain is stably maintained above 9.5 dBi, and the peak gain of 9.7 dBi is reached at 5.62 GHz. This proves that the design method of this lightweight heterogeneous high-gain circularly polarized patch antenna array can achieve stable high-gain characteristics in the operating frequency band of UAVs.

[0042] In summary, the lightweight heterogeneous high-gain circularly polarized patch antenna array proposed in this invention, through the adoption of a lightweight heterogeneous design concept and sequential rotating feed technology, achieves a balance between wide impedance bandwidth, high gain within the axial ratio bandwidth, and circular polarization radiation performance while maintaining a low profile, lightweight design, and miniaturization, resulting in excellent performance within the anti-drone operating frequency band. The lightweight heterogeneous design concept effectively reduces dielectric loss and improves the antenna's radiation gain within the usable frequency band. Simultaneously, the suspended microstrip structure of the dielectric layer beneath the fan-shaped patches reduces the physical size difference between fan-shaped patch antennas with different center angles. This invention features a simple structure and low profile. The overall antenna profile height is only 0.07 times the free-space wavelength of the antenna's operating center frequency. Mechanical support is achieved through metal short-circuit pins, and the combination with a 1-to-2 T-type microstrip power divider network significantly reduces processing and assembly difficulty and manufacturing costs. This makes it highly practical in the anti-drone field.

[0043] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0044] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A circularly polarized patch antenna array, characterized in that, include: floor; A first sector-shaped patch and a second sector-shaped patch are disposed above the floor. The central angle of the first sector-shaped patch is smaller than that of the second sector-shaped patch. The second sector-shaped patch is orthogonally distributed relative to the first sector-shaped patch, rotated 90° around the central axis of the antenna. A power supply network is disposed below the floor; the power supply network is connected to the first sector patch and the second sector patch respectively, and the power supply network provides excitation signals with a 90° phase difference to the first sector patch and the second sector patch respectively according to the input radio frequency signal; Wherein, a first dielectric layer is provided between the first sector patch and the floor, the first dielectric layer including a dielectric one located above and an air dielectric two located below and adjacent to the floor; a second dielectric layer is provided between the second sector patch and the floor, the second dielectric layer including a dielectric three located above and the air dielectric two located below and adjacent to the floor; the relative permittivity of the dielectric one is greater than the relative permittivity of the dielectric three.

2. The circularly polarized patch antenna array according to claim 1, characterized in that, The central angles of the first sector patch and the second sector patch are both between 180° and 350°, and the difference between the central angle of the second sector patch and the central angle of the first sector patch is greater than 15°.

3. The circularly polarized patch antenna array according to claim 1, characterized in that, The antenna array also includes metal short-circuit pins, which are respectively connected between the first sector patch and the ground plane, and between the second sector patch and the ground plane, serving as a mechanical support structure for the first sector patch and the second sector patch to be suspended above the second air medium.

4. A circularly polarized patch antenna array according to claim 1, characterized in that, The power supply network includes a T-shaped microstrip power divider network (1 to 2) and a microstrip delay line. The electrical length of the microstrip delay line is one-quarter of the wavelength of the antenna's operating center frequency. The phase of the input signal is configured through the microstrip delay line. The power supply network is configured such that the signal input to the first sector patch lags behind the signal of the second sector patch by 90° phase to form left-hand circularly polarized radiation; or, the signal input to the first sector patch leads the signal of the second sector patch by 90° phase to form right-hand circularly polarized radiation.

5. A circularly polarized patch antenna array according to claim 4, characterized in that, The power supply network is connected to the first sector patch and the second sector patch via different coaxial probes passing through the floor and the second air medium, respectively.

6. A circularly polarized patch antenna array according to claim 1, characterized in that, The height of the second sector patch from the floor is not less than the height of the first sector patch from the floor.

7. A circularly polarized patch antenna array according to claim 6, characterized in that, The height difference between the first sector patch and the second sector patch is no greater than 0.015 times the free space wavelength corresponding to the antenna's operating center frequency.

8. A circularly polarized patch antenna array according to claim 1, characterized in that, The overall profile height of the antenna array is no greater than 0.07 times the free space wavelength corresponding to the antenna's operating center frequency.

9. A circularly polarized patch antenna array according to claim 1, characterized in that, The center-to-center distance between the first sector patch and the second sector patch is 0.7-1 times the free space wavelength corresponding to the working center frequency.

10. The design method of the circularly polarized patch antenna array according to any one of claims 1-9, characterized in that, Includes the following steps: Construct a floor and a power supply network located beneath the floor; Above the floor, a first sector patch and a second sector patch with different central angles are arranged such that the second sector patch with a larger central angle is orthogonally distributed relative to the first sector patch with a smaller central angle, rotated 90° around the antenna central axis. A first medium layer comprising medium one and air medium two is disposed between the first sector patch and the floor, and a second medium layer comprising medium three and air medium two is disposed between the second sector patch and the floor; Based on the difference in the central angle between the first sector patch and the second sector patch, the relative permittivity of the first dielectric is set to be greater than that of the third dielectric, so as to reduce the physical size difference between sector patches with different central angles. The power supply network is configured to pass through the floor and the air medium, respectively connecting to the first sector patch and the second sector patch, and based on the one-to-two power splitting structure and quarter-wavelength delay line, to provide radio frequency signals with a 90° phase difference to the first sector patch and the second sector patch.

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