Low profile all-metal circularly polarized reflective array antenna

Abstract

The application discloses a low-profile full-metal circularly polarized reflective array. The reflective array antenna comprises a circularly polarized horn antenna for feeding, a full-metal circularly polarized reflective array, and a support for fixing the circularly polarized horn antenna and the full-metal circularly polarized reflective array. The circularly polarized reflective array is composed of units with different reflection phases, and the units are adjusted by rotation to form a required radiation beam. The antenna has a full-metal structure, and has certain advantages over a reflective array realized by using a dielectric substrate in application scenarios such as high power and conformal. The antenna has the characteristics of simple structure, low profile, low cost and short design period, and is suitable for satellite communication and radar fields.

Description

Technical Field

[0001] This invention belongs to the field of reflective array antenna technology, and particularly relates to a low-profile all-metal circularly polarized reflective array antenna. Background Technology

[0002] Reflector array antennas, with their simple feeding structure and rich electromagnetic wave modulation capabilities, have been a research hotspot in antenna design in recent years compared to traditional antenna arrays. Circularly polarized antennas exhibit superior performance in addressing polarization mismatch, suppressing rain and fog interference, and eliminating the Faraday effect. Therefore, circularly polarized antennas are widely used in satellite communications and radar applications.

[0003] Circularly polarized reflective array antennas inherit the advantages of reflective array antennas while offering superior bandwidth performance compared to traditional circularly polarized array antennas. There are generally two methods for implementing circularly polarized reflective arrays: one uses a circularly polarized feed and rotates the antenna elements to achieve phase adjustment; the other uses a linearly polarized feed and adjusts the elements to achieve a 90-degree phase difference in orthogonal radiation directions, thus achieving circular polarization. The first method is simpler and more direct than the second, and it also offers a wider bandwidth.

[0004] Current research on circularly polarized reflective arrays generally employs planar structures, with limited research on all-metal circularly polarized reflective arrays. All-metal circularly polarized arrays offer better efficiency than planar structures. Furthermore, in specific scenarios such as conformal antenna applications and high-power applications, all-metal arrays exhibit better structural strength and power handling characteristics compared to planar antennas using dielectric substrates. Therefore, research on all-metal circularly polarized reflective arrays holds significant research and practical value. Summary of the Invention

[0005] The purpose of this invention is to provide a low-profile all-metal circularly polarized reflective array antenna, which has the advantages of simple structure, short design cycle, low cost and broadband operation.

[0006] To solve the above-mentioned technical problems, the specific technical solution of the present invention is as follows:

[0007] A low-profile all-metal circularly polarized reflective array antenna includes a circularly polarized horn antenna for feeding, a bracket for fixing the circularly polarized horn antenna and the circularly polarized reflective array antenna, and the circularly polarized reflective array antenna; the circularly polarized reflective array antenna is composed of M×N reflective antenna elements; the circularly polarized horn antenna and the circularly polarized reflective array antenna are fixed to the bracket by screws.

[0008] The antenna unit includes: an I-shaped radiating structure, a T-shaped grounding wire, and a metal block surrounding it; the I-shaped radiating structure is composed of two circular rings and a rectangle connected together; the T-shaped grounding wire is used to connect the I-shaped radiating structure and the metal ground plane; the I-shaped radiating structure and the T-shaped grounding wire constitute the main structure of the antenna unit; the metal block surrounding it optimizes the reflection performance of the antenna unit when electromagnetic waves are incident at large angles; by rotating the main antenna unit, a 360° reflection phase is achieved.

[0009] Furthermore, the focal diameter ratio of the circularly polarized reflective array antenna is set to around 0.5.

[0010] Furthermore, the required compensation phase for the array elements is calculated based on the desired radiation direction.

[0011] The phase compensation formula is:

[0012] φ mn =k0(R mn -sin(θ)(x mn cos(ψ)+y mn sin(ψ))+φ0

[0013] In the formula φ m For the phase compensation required for the m-th row and n-th column cell, k0 is the wave number in free space, R mn The distance from the phase center of the circularly polarized horn antenna to the center of this element is (x mn y mn (θ, ψ) represents the center coordinates of the unit, (θ, ψ) represents the direction of the target array antenna beam, and φ0 represents the phase constant.

[0014] The phase that each unit needs to rotate is determined by the corresponding curve of phase and rotation angle provided by the reflection unit.

[0015] Furthermore, the circularly polarized horn antenna and the reflector array antenna are made of aluminum, and the support can be made of resin or plastic.

[0016] Excite the circularly polarized horn antenna and observe the standing wave ratio, axial ratio, and radiation pattern of the circularly polarized reflector array.

[0017] The performance specifications of the all-metal low-profile circularly polarized antenna provided by this invention are as follows:

[0018] Frequency band: 9.6GHz~11.6GHz; Polarization: circular polarization; Radiation direction: side-firing; Voltage standing wave ratio: less than 1.8; Antenna gain: 13.4dBi~14.7dBi; Axial ratio: less than 3dB; Nominal impedance: 50Ω.

[0019] The low-profile all-metal circularly polarized reflective array antenna of the present invention has the following advantages:

[0020] This invention features a simple structure and low profile, making it suitable for satellite communication and radar applications. Compared to reflective arrays implemented on dielectric substrates, it offers advantages in conformal and high-power scenarios. The antenna element can be rotated to cover a 360-degree phase, facilitating reflective array design. Simulation results show that the antenna of this invention can achieve a VSWR of less than 1.8 and an axial ratio of less than 3 dB within the 9.6 GHz to 11.6 GHz range. The in-band antenna gain is 13.4 dBi to 14.7 dBi. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention.

[0022] Figure 2 This is a schematic diagram of the antenna unit structure of the present invention.

[0023] Figure 3 This is a simulation diagram of the phase and rotation angle of the antenna element of the present invention at 10 GHz.

[0024] Figure 4 This is a simulation diagram of the antenna standing wave of the present invention.

[0025] Figure 5 This is a simulation diagram of the antenna gain of the present invention.

[0026] Figure 6 This is a simulation diagram of the antenna axial ratio of the present invention.

[0027] Figure 7 The simulated gain pattern of the antenna of this invention at 9.6 GHz is shown.

[0028] Figure 8 The simulated gain pattern of the antenna of this invention at 10 GHz is shown.

[0029] Figure 9 The simulated gain pattern of the antenna of this invention at 10.5 GHz is shown.

[0030] Figure 10 The simulated gain pattern of the antenna of this invention at 11 GHz is shown.

[0031] Figure 11 The simulated gain pattern of the antenna of this invention at 11.6 GHz is shown.

[0032] The markings in the diagram are as follows: 1. Circularly polarized horn antenna; 2. Support frame; 3. Circularly polarized reflective array antenna; 4. T-shaped grounding wire; 5. I-shaped radiating structure; 6-17. Metal blocks. Detailed Implementation

[0033] To better understand the purpose, structure, and function of this invention, a low-profile all-metal circularly polarized reflective array antenna of this invention will be described in further detail below with reference to the accompanying drawings.

[0034] Figure 1 This is a schematic diagram of the invention. Specifically, the model includes: a feed-source circularly polarized horn antenna 1, a support 2 for fixing the antenna, and a circularly polarized reflective array antenna 3. The circularly polarized horn antenna 1 and the circularly polarized reflective array antenna 3 are fixed to the support 2 with screws. To achieve the requirement of a low profile, the focal diameter ratio of the reflective array is around 0.5. The circularly polarized horn antenna 1 and the circularly polarized reflective array antenna 3 are made of aluminum, and the support is made of resin.

[0035] Figure 2 This is a schematic diagram of the antenna unit structure of the invention. Specifically, the unit model includes: a T-shaped grounding wire 4, an I-shaped radiating structure 5, and metal blocks 6 to 17 arranged around the radiating structure. The T-shaped grounding wire 4 is used to connect the I-shaped radiating structure 5 and the ground plane. The I-shaped radiating structure is composed of two circular rings and a rectangle connected together. The T-shaped grounding wire 4 and the I-shaped radiating structure 5 together form the main structure of the unit antenna. Metal blocks 6 to 17 can enhance the antenna unit's ability to reflect electromagnetic waves incident at large angles. Metal blocks 6 to 9 are arranged at the edge of the unit antenna, and metal blocks 10 to 17 are symmetrically arranged around the main structure of the antenna unit. The reflection phase of the unit can be changed by rotating the main structure of the antenna unit, i.e., changing the rotation angle. Figure 3 The simulation shows the correspondence between the rotation angle and the phase, demonstrating that the antenna element can cover the 360-degree reflection phase by rotation, thus meeting the requirements of the designed array.

[0036] The reflective array antenna 3 is composed of antenna elements with different rotation angles. After determining the position of the circularly polarized horn antenna 1, the phase compensation formula can be used:

[0037] φ mn =k0(R mn -sin(θ)(x mn cos(ψ)+y mn sin(ψ))+φ0

[0038] Determine the required phase for each unit. Where φ... mn For the phase compensation required for the m-th row and n-th column cell, k0 is the wave number in free space, R mn The distance from the phase center of the circularly polarized horn antenna to the center of this element is (x mn ,y mn (θ, ψ) represents the center coordinates of the element, (θ, ψ) represents the direction of the target array antenna beam, and φ0 represents the phase constant. According to... Figure 3The required rotation angle is obtained by giving the correspondence between the phase and the rotation angle, thereby determining the structure of each element in the reflective array antenna 3.

[0039] The standing wave and radiation performance of the antenna were simulated using CST full-wave simulation software. Figure 4 The simulated antenna standing wave (SWR) curve shows that the designed antenna satisfies an SWR of less than 1.8 between 9.6 GHz and 11.6 GHz. Figure 5 The simulated antenna gain curves are presented. It can be seen from the figure that the gain ranges from 13.4dB to 14.7dB between 9.6GHz and 11.6GHz. Figure 6 The simulated axial ratio curve of the antenna is given, which shows that the designed antenna satisfies an axial ratio of less than 3dB from 9.6GHz to 11.6GHz.

[0040] Figure 7 , Figure 8 , Figure 9 , Figure 10 and Figure 11 Simulated gain patterns of the reflector array antenna at 9.6 GHz, 10 GHz, 10.5 GHz, 11 GHz and 11.6 GHz are presented.

[0041] This invention proposes a low-profile, all-metal circularly polarized reflective array antenna. The antenna's performance was verified using the simulation software CST. Simulation results show that the designed antenna can achieve a VSWR of less than 1.8 in the 9.6 GHz to 11.6 GHz range. It also achieves an axial ratio of less than 3 dB in the same range, with a gain ranging from 13.4 dBi to 14.7 dBi within the operating frequency band. The antenna exhibits a good radiation pattern within its operating frequency band. Due to its all-metal structure, the antenna shows potential in conformal and high-power applications. The antenna of this invention features a simple structure, low profile, low cost, and short design cycle, making it suitable for satellite communication and radar applications.

[0042] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A low-profile all-metal circularly polarized reflective array antenna, characterized in that, It includes a circularly polarized horn antenna (1) for feeding, a bracket (2) for fixing the circularly polarized horn antenna (1) and the circularly polarized reflective array antenna (3), and the circularly polarized reflective array antenna (3); the circularly polarized reflective array antenna (3) is composed of M×N reflective antenna elements; The circularly polarized horn antenna (1) and the circularly polarized reflective array antenna (3) are fixed on the bracket (2); The antenna unit includes: an I-shaped radiating structure (5), a T-shaped grounding wire (4), and a metal block surrounding it; the I-shaped radiating structure (5) is composed of two circular rings and a rectangle connected together; the T-shaped grounding wire (4) is used to connect the I-shaped radiating structure (5) and the metal ground; the I-shaped radiating structure (5) and the T-shaped grounding wire (4) constitute the main structure of the antenna unit; the metal block surrounding it optimizes the reflection performance of the antenna unit when electromagnetic waves are incident at large angles; by rotating the main structure of the antenna unit, a 360° reflection phase is achieved.

2. The low-profile all-metal circularly polarized reflective array antenna according to claim 1, characterized in that, The focal diameter ratio of the circularly polarized reflective array antenna (3) is set to around 0.

5.

3. The low-profile all-metal circularly polarized reflective array antenna according to claim 2, characterized in that, Calculate the required compensation phase for the array elements based on the desired radiation direction. The phase compensation formula is: ； In the formula The phase compensation required for the m-th row and n-th column cell Let be the wave number in free space. This is the distance from the phase center of the circularly polarized horn antenna to the center of this element. The center coordinates of this cell are... The direction of the target array antenna beam. The phase constant is used to determine the phase that each unit needs to rotate based on the corresponding curve of phase and rotation angle provided by the reflection unit.

4. The low-profile all-metal circularly polarized reflective array antenna according to claim 3, characterized in that, The circularly polarized horn antenna (1) and the reflective array antenna are made of aluminum, and the support is made of resin or plastic.

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