Bidirectional inclined circularly polarized wave beam fan-shaped annular patch antenna and design method thereof

Abstract

The invention discloses a bidirectional inclined circularly polarized beam sector-ring patch antenna and a design method thereof, and the method comprises the steps: determining a first odd-order resonance mode which is used for representing the antenna base-order resonance of an antenna working frequency band; determining whether a first odd order resonance mode exists on the sector-ring-shaped patch structure or not, wherein the sector-ring-shaped patch structure is an antenna radiation unit structure; if the first odd-order resonance mode exists on the sector-ring-shaped patch structure, adjusting the arc length of an outer arc of the sector-ring-shaped patch structure and the ratio of the arc length of an inner arc to the arc length of an outer arc of the sector-ring-shaped patch structure so as to form the first odd-order resonance mode on the sector-ring-shaped patch structure; determining patch surface current distribution of the sector-ring-shaped patch structure in the first odd-order resonance mode, wherein the patch surface current distribution is used for determining an excitation position of an excitation signal of the first odd-order resonance mode; determining a grounding structure, wherein the grounding structure provides physical grounding for the excitation signal; and determining a short-circuit structure, wherein the short-circuit structure is used for connecting the radius end and the inner arc end of the sector-ring-shaped patch structure with the grounding structure.

Description

Technical Field

[0001] The invention relates to a bidirectional tilted circular polarization beam fan ring patch antenna and a design method thereof, belonging to the technical field of microwaves and antennas. Background Art

[0002] As the operating frequency of wireless communication systems becomes higher and higher, the operating frequency of antennas also increases, which makes antenna design and development more difficult. Compared with linearly polarized antennas, circularly polarized (CP) antennas are widely used in many wireless applications because they can effectively reduce multipath interference and polarization mismatch losses caused by misalignment. Among them, planar circularly polarized antennas, such as microstrip circularly polarized antennas, have attracted widespread attention because they can conform to the surface of the carrier. However, most of their radiation beams are end-fired, which is not suitable for some situations where the main radiation beam is required to form a certain angle with the antenna plane. With the development of wireless communication technology, there is an urgent need to manufacture bidirectional circularly polarized antennas with tilted beam radiation capabilities to improve the quality of multipath signal reception, especially in satellite, navigation, vehicle networking, and space / polarization diversity communication systems.

[0003] Bidirectional circularly polarized antennas can provide spatial / polarization diversity capabilities at the same time. Generally speaking, bidirectional circularly polarized antennas can be divided into five categories according to their implementation type: (1) disc-shaped monopole antenna; (2) non-uniform even-mode square ring antenna; (3) complementary dipole antenna; (4) aperture antenna; (5) dielectric resonant antenna. In addition, circularly polarized antennas with dual inductance and bidirectionality can also be realized through periodic structures or metasurfaces. However, the bidirectional circularly polarized antennas of these structures are relatively complex and have more design parameters. Therefore, how to design a bidirectional circularly polarized antenna with a minimal structure and fewer antenna parameters is a challenging problem. The existing technology has been able to solve the design of end-fire / back-fire bidirectional circularly polarized antennas, but cannot realize the design of bidirectional tilted beam circularly polarized antennas.

[0004] In view of this, it is necessary to propose a more simplified, efficient and flexible bidirectional tilted circularly polarized beam fan ring patch antenna and its design method to promote the widespread application of bidirectional tilted circularly polarized beam antenna technology in various communication systems and provide important support for the development of future wireless communication technology. Summary of the invention

[0005] The purpose of the present invention is to solve the deficiencies in the prior art and to provide a bidirectional tilted circularly polarized beam fan-ring patch antenna and a design method thereof. The antenna has a simple patch structure and clear mathematical principles, and can achieve circularly polarized beam tilt capability in the azimuth yz plane.

[0006] The present invention adopts the following technical solutions to solve the above technical problems:

[0007] On the one hand, the present invention provides a design method for a bidirectional tilted circularly polarized beam fan ring patch antenna, the design method comprising:

[0008] Determining a first odd-order resonance mode, where the first odd-order resonance mode is used to characterize a fundamental-order resonance of the antenna in an operating frequency band of the antenna;

[0009] Determine whether there is a first odd-order resonant mode on the fan-shaped ring patch structure, where the fan-shaped ring patch structure is an antenna radiation unit structure;

[0010] If a first odd-order resonance mode exists on the fan-shaped patch structure, adjusting the arc length of the outer arc and the arc length ratio of the inner and outer arcs of the fan-shaped patch structure to form the first odd-order resonance mode on the fan-shaped patch structure;

[0011] Determine a patch surface current distribution of the fan-shaped patch structure in the first odd-order resonance mode, wherein the patch surface current distribution is used to determine an excitation position of an excitation signal of the first odd-order resonance mode;

[0012] Determining a grounding structure, wherein the grounding structure provides physical grounding for the excitation signal;

[0013] A short-circuit structure is determined, where the short-circuit structure is used to connect the radius end and the inner arc end of the fan-shaped patch structure with the grounding structure.

[0014] On the other hand, the present invention provides a bidirectional tilted circularly polarized beam fan ring patch antenna, the antenna is obtained by the above-mentioned design method, comprising:

[0015] The fan-shaped patch structure is arranged above the ground structure and is parallel to the ground structure;

[0016] The fan-shaped patch structure is connected to the ground structure through the short-circuit structure;

[0017] The fan-shaped patch structure is used to form a first odd-order resonance mode, and the first odd-order resonance mode forms a current distribution on the patch surface;

[0018] The excitation signal is located on the angular bisector of the current distribution on the patch surface of the fan-shaped patch structure, and is connected to the fan-shaped patch structure and the grounding structure.

[0019] The first odd-order resonance mode is used to characterize the antenna fundamental-order resonance in the antenna operating frequency band. The length of the outer arc of the fan-ring patch structure is twice the wavelength corresponding to the antenna fundamental-order resonance frequency. The ratio of the arc lengths of the outer and inner arcs of the fan-ring patch structure is greater than 1.5.

[0020] An air medium is filled between the fan-shaped patch structure and the ground structure.

[0021] The distance between the excitation signal and the center of the fan-shaped patch structure ranges from 1.1 times the inner diameter of the fan-shaped patch structure to 0.9 times the outer diameter of the fan-shaped patch structure.

[0022] The resonance mode adopted by the antenna is the first odd-order resonance mode (α is the central angle of the fan-shaped patch structure).

[0023] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects:

[0024] (1) The antenna has a bidirectional tilted circularly polarized beam in the elevation plane, that is, the optimal tilt angle of the circularly polarized beam appears in the yz plane with an azimuth angle of 90°, and the tilt angle of the circularly polarized beam is ±25°.

[0025] (2) The antenna adopts the fundamental resonant mode and has a very simple structure, which effectively reduces the structural complexity of the bidirectional circularly polarized antenna. At the same time, it has the advantages of low profile, good bidirectional circularly polarized radiation characteristics, easy processing and manufacturing, and convenient mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the implementation flow of a design method for a bidirectional tilted circularly polarized beam fan ring patch antenna of the present invention.

[0027] Figure 2 It is a schematic diagram of the top view structure and the reference coordinate system of Example 1 of the bidirectional tilted circularly polarized beam fan ring patch antenna of the present invention;

[0028] Figure 3 3D schematic diagram and reference coordinate system of bidirectional tilted circular polarization beam fan ring patch antenna embodiment 1 of the present invention; Figures 2 to 3 In the figure, 1 is a fan-shaped patch structure, 2 is a grounding structure, 3 is a short-circuit structure, and 4 is an excitation signal.

[0029] Figure 4 is the reflection coefficient (S) of the bidirectional tilted circular polarization beam fan ring patch antenna embodiment 1 of the present invention 11 );

[0030] Figure 5 It is the radiation pattern of the bidirectional tilted circular polarization beam fan ring patch antenna embodiment 1 of the present invention in the yz plane;

[0031] Figure 6 It is the axial ratio frequency response of the bidirectional tilted circular polarization beam fan ring patch antenna embodiment 1 of the present invention at different elevation angles in the yz plane;

[0032] Figure 7 It is the radiation gain and efficiency of embodiment 1 of the bidirectional tilted circularly polarized beam fan ring patch antenna of the present invention. DETAILED DESCRIPTION

[0033] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention.

[0034] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0035] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings:

[0036] Figure 1 FIG. 1 is a flow chart of the antenna design method of the present invention. Figure 1 As shown, the method includes:

[0037] Determine a first odd-order resonance mode, where the first odd-order resonance mode is used to characterize the antenna fundamental-order resonance in the antenna operating frequency band. When designing an antenna, different antenna design requirements require different resonances. Therefore, the first odd-order resonance mode implemented on the antenna can be determined based on the antenna design requirements.

[0038] Determine whether there is a first odd-order resonant mode on the fan-ring patch structure, where the fan-ring patch structure is an antenna radiation unit structure; if there is a first odd-order resonant mode on the fan-ring patch structure, adjust the outer arc length and the ratio of the inner and outer arc lengths of the fan-ring patch structure to form a first odd-order resonant mode on the fan-ring patch structure; when designing the antenna, after determining the first odd-order resonant mode, the central angle of the fan-ring patch structure can be determined according to the order of the resonant mode; and determine the inner and outer diameters of the fan-ring patch structure according to the operating frequency band of the antenna.

[0039] Determine the patch surface current distribution of the fan-ring patch structure in the first odd-order resonance mode, and the patch surface current distribution is used to determine the excitation position of the excitation signal of the first odd-order resonance mode; determine the grounding structure, and the grounding structure provides physical grounding for the excitation signal; determine the short-circuit structure, and the short-circuit structure is used to connect the radius end and the inner arc end of the fan-ring patch structure to the grounding structure.

[0040] like Figure 2 and Figure 3 As shown, the present invention provides a bidirectional tilted circularly polarized beam fan-ring patch antenna and a design method thereof, comprising a fan-ring patch structure 1, a grounding structure 2, a short-circuit structure 3 and an excitation signal 4; the radiation structure constituting the antenna is a semi-closed structure, which is composed of a fan-ring patch structure 1, a grounding structure 2 and a short-circuit structure 3.

[0041] The fan-shaped patch structure 1 is located above the ground structure 2 and is parallel to the ground structure 2. The fan-shaped patch structure 1 is connected to the ground structure 2 through a short-circuit structure 3 with two radii and one inner arc length. The excitation signal 4 is located on the angular bisector of the fan-shaped patch structure.

[0042] The length of the outer arc of the fan-ring patch structure 1 is one time the wavelength corresponding to the fundamental resonant frequency of the antenna. The ratio of the arc lengths of the outer and inner arcs of the fan-ring patch structure 1 is greater than 1.5; the air medium is filled between the fan-ring patch structure 1 and the grounding structure 2. The distance between the excitation signal 4 and the center of the fan-ring patch structure 1 ranges from 1.1 times the inner diameter of the fan-ring patch structure 1 to 0.9 times the outer diameter of the fan-ring patch structure 1. The resonant mode adopted by the antenna is the fundamental resonant mode, and its resonant mode is controlled by the center angle of the fan-ring patch structure. It has a bidirectional tilted circularly polarized beam in the pitch plane, and the optimal tilt angle of the circularly polarized beam appears in the yz plane with an azimuth angle of 90°, and the tilt angle of the circularly polarized beam is ±25°.

[0043] Compared with conventional circularly polarized antennas, the design method of a bidirectional tilted circularly polarized beam fan-ring patch antenna of the present invention adopts a novel fan-ring patch structure, and realizes circular polarization by making the amplitude of the electric field components radiated by the fundamental resonant mode of the antenna on the pitch plane equal and the phase orthogonal relationship. The structure of the antenna is simple and easy to design. The resonant frequency and the tilt angle of the circularly polarized beam are adjusted by correcting the arc length of the outer arc of the fan-ring patch structure and the ratio of the arc length of the inner and outer arcs and the position of the excitation signal, thereby meeting the setting requirements of the wireless system.

[0044] Embodiment 1:

[0045] The antenna of this embodiment uses an air medium (dielectric constant is 1), the distance between the fan-ring patch structure 1 and the ground structure 2 is 5mm, the outer diameter of the fan-ring patch structure is 38mm, the inner diameter is 9.5mm, the ratio of the inner and outer diameters is 4, the central angle of the fan-ring patch structure is 180°, the radius of the ground structure is 90mm, the distance between the excitation signal and the center of the circle is 25mm, and the size radius of the excitation signal is 0.65mm.

[0046] Compare with Figure 4 , Figure 4 The reflection coefficient S of the antenna in Example 1 is given as 11 .Depend on Figure 4It can be seen that the working frequency range of the antenna (S 11 >-10dB) is 2.28~2.68GHz, and the relative bandwidth reaches 16.1%. It can be seen that the antenna has a wide bandwidth under single-mode resonance conditions, covering the WLAN frequency band (2.4~2.484GHz).

[0047] Compare with Figure 5 , Figure 5 The yz plane radiation pattern of the antenna of Example 1 at 2.46 GHz is given. Figure 5 It can be seen that the antenna exhibits a bidirectional tilted circular polarization beam on the yz plane, the solid line is left-hand circular polarization, the dotted line is right-hand circular polarization, and the beam tilt angles are ±25° respectively.

[0048] Compare with Figure 6 , Figure 6 The axial ratio frequency response of the antenna of Example 1 at different elevation angles in the yz plane is given. Figure 6 It can be seen that within the entire antenna operating frequency range, the antenna has an axial ratio bandwidth of less than 3 dB at an angle (90° in azimuth and ±25° in elevation).

[0049] Compare with Figure 7 , Figure 7 The radiation efficiency of the antenna in Example 1 and the radiation gain in the direction of azimuth angle of 90° and elevation angle of ±25° are given. Figure 7 It can be seen that within the operating frequency range, the radiation gain of the antenna is greater than 3.8dBi, the average radiation gain is 4.27 / 4.36dB, and the average efficiency is 96.25%.

[0050] To summarize, the bidirectional tilted circularly polarized beam fan-ring patch antenna designed in the present invention can obtain good circularly polarized beam tilt capability for different operating frequency bands of wireless communication systems by simply adjusting the central angle and outer arc length of the fan-ring patch structure, the ratio of the inner and outer arc lengths, and the position of the excitation signal, thereby achieving flexible universality and good compatibility in antenna design and application.

[0051] The above description is only a specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any person familiar with the technology can understand and think of any changes or substitutions within the technical scope disclosed by the present invention, which should be included in the scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A design method for a bidirectional tilted circularly polarized beam fan ring patch antenna, characterized in that: include: Determining a first odd-order resonance mode, where the first odd-order resonance mode is used to characterize a fundamental-order resonance of the antenna in an operating frequency band of the antenna; Determine whether there is a first odd-order resonant mode on the fan-shaped ring patch structure, where the fan-shaped ring patch structure is an antenna radiation unit structure; If a first odd-order resonance mode exists on the fan-shaped patch structure, adjusting the arc length of the outer arc and the arc length ratio of the inner and outer arcs of the fan-shaped patch structure to form the first odd-order resonance mode on the fan-shaped patch structure; Determine a patch surface current distribution of the fan-shaped patch structure in the first odd-order resonance mode, wherein the patch surface current distribution is used to determine an excitation position of an excitation signal of the first odd-order resonance mode; Determining a grounding structure, wherein the grounding structure provides a physical ground for the excitation signal; A short-circuit structure is determined, where the short-circuit structure is used to connect the radius end and the inner arc end of the fan-shaped patch structure with the grounding structure.

2. A bidirectional tilted circular polarization beam fan ring patch antenna, characterized in that: include: The fan-shaped patch structure is arranged above the ground structure and is parallel to the ground structure; The fan-shaped patch structure is connected to the ground structure through the short-circuit structure; The fan-shaped patch structure is used to form a first odd-order resonance mode, and the first odd-order resonance mode forms a current distribution on the patch surface; The excitation signal is located on the angular bisector of the current distribution on the patch surface of the fan-shaped patch structure, and is connected to the fan-shaped patch structure and the grounding structure.

3. A bidirectional tilted circularly polarized beam fan-ring patch antenna as described in claim 2, characterized in that: the first odd-order resonance mode is used to characterize the antenna fundamental-order resonance of the antenna working frequency band, and the length of the outer arc of the fan-ring patch structure is twice the wavelength corresponding to the antenna fundamental-order resonance frequency.

4. A bidirectional tilted circularly polarized beam fan-ring patch antenna as described in claim 2, characterized in that the ratio of the arc lengths of the outer and inner arcs of the fan-ring patch structure is greater than 1.

5.

5. A bidirectional tilted circularly polarized beam fan-ring patch antenna as described in claim 2, characterized in that: an air medium is filled between the fan-ring patch structure and the ground structure.

6. A bidirectional tilted circularly polarized beam fan-ring patch antenna as described in claim 2, characterized in that the distance between the excitation signal and the center of the fan-ring patch structure ranges from 1.1 times the inner diameter of the fan-ring patch structure to 0.9 times the outer diameter of the fan-ring patch structure.

7. The method according to claim 1, wherein the resonance mode adopted by the antenna is the first odd-order resonance mode. (α is the central angle of the fan-shaped patch structure).

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