Low-grating lobe open waveguide antenna

Abstract

The utility model discloses a low-grating lobe open waveguide antenna in the field of antennas, which comprises a waveguide shell integrally in a horn mouth shape, a small-caliber end of the waveguide shell is an input port, a large-caliber end of the waveguide shell is an output port, and the inside of the waveguide shell is divided into at least three stages of matching steps; the distribution part is fixedly arranged at the output port of the waveguide shell; the suppression part is arranged on the matching step close to the output port of the waveguide shell and connected with the distribution part, the suppression part is of a plate-shaped structure, and the extension direction of the suppression part is the E-plane direction of the waveguide shell; the beneficial effects of the utility model are that the output port of the waveguide housing is provided with the cross-shaped grid bar and the suppression metal block, so that the output port can be divided into four independent open waveguide radiation units for radiation, and the power division network level and grating lobe level of an array antenna formed by the units are reduced.

Description

Technical Field

[0001] This utility model relates to the field of antennas, specifically to a low grating lobe open waveguide antenna. Background Technology

[0002] High-power microwave antennas are a crucial component of high-power microwave radiation systems, and their performance directly affects the effective delivery of energy to the target. Current high-power microwave technology focuses on achieving higher efficiency, smaller size, and higher peak power, requirements that traditional high-power antennas such as mode-switching antennas, COBRA antennas, and parabolic reflector antennas struggle to meet. However, open-aperture waveguide planar antennas, with their low profile, high aperture efficiency, large power capacity, and ease of fabrication, can meet the needs of various confined space scenarios and have received widespread attention and research in recent years.

[0003] Existing studies on open-aperture waveguides have shown that by loading a metal plate at the same height as the radiating aperture, the radiating structure can be approximated as divided into two small-aperture units, improving the uniformity of the aperture electric field and increasing gain and aperture efficiency. While using a power divider network to excite the small-aperture radiating units can reduce the number of power dividers, this is still not suitable for confined space scenarios and hinders system miniaturization. Therefore, further reduction in the number of power divider network stages is needed.

[0004] To address this, we propose a low grating lobe aperture waveguide antenna. Summary of the Invention

[0005] To address the aforementioned shortcomings of the existing technology, this utility model provides a low grating lobe opening waveguide antenna.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by this utility model is as follows:

[0007] A low-lobed open waveguide antenna includes: a waveguide housing, which is generally horn-shaped, with a small-diameter end as the input port and a large-diameter end as the output port, and the waveguide housing is internally divided into at least three matching steps; a distribution component, which is fixedly disposed at the output port of the waveguide housing and is used to divide the output port of the waveguide housing into multiple independent open waveguide radiating elements; and a suppression component, which is disposed on the matching steps near the output port of the waveguide housing and connected to the distribution component, the suppression component having a plate-like structure and extending in the E-plane direction of the waveguide housing.

[0008] Impedance matching is achieved by setting a three-stage matching ladder, resulting in a simple structure and lower profile. Compared to a two-stage matching ladder, it provides better impedance matching. By setting a distributor at the output port of the waveguide housing to divide the output port into multiple independent waveguide radiation units, the system weight and profile height are reduced, and the antenna volume is decreased. Furthermore, by using this invention as an array as a waveguide array antenna, the number of power divider network stages of the waveguide array antenna can be reduced. By setting a suppression component along the E-plane direction of the waveguide housing, edge diffraction of the aperture can be reduced, thereby reducing the grating lobe level of the array antenna after this invention is used as a unit to form an array.

[0009] Further defining the waveguide housing, the interior from the input port to the output port includes a first matching step, a second matching step, and a third matching step in sequence.

[0010] Further defined, the distribution component is cross-shaped and includes two intersecting grid bars. The four ends of the two grid bars are fixedly connected to the inner wall of the output port of the waveguide housing. The left and right side walls of the vertical grid bars are provided with arc protrusions, which are symmetrically arranged about the intersection of the two grid bars.

[0011] Setting the distributor in a cross shape enables a one-to-four power distribution network at the output port, dividing the radiating element into independent small aperture units, and achieving equal amplitude and in-phase radiation of the four open waveguide units. This simplifies the power distribution network and helps improve aperture efficiency. Meanwhile, setting arc protrusions on the vertical gratings, in conjunction with the suppression components, helps to homogenize the electric field of each independent small aperture waveguide radiating unit and reduce the grating lobe level of the antenna array after unit arraying.

[0012] Further defined, the suppressing component includes two suppressing metal blocks, which are disposed opposite to each other at both ends of the grid strip with arc protrusions, and their bottoms are fixedly disposed on the third matching step. The top of the suppressing metal blocks is fixedly connected to the bottom surfaces of both ends of the grid strip with arc protrusions.

[0013] Further specifying, the corners of the side walls of the first matching step, the second matching step, and the third matching step are all rounded.

[0014] The beneficial effects of this utility model are as follows: by setting a cross-shaped grating and a suppressing metal block at the output port of the waveguide housing, the output port can be divided into four independent open waveguide radiation units for radiation, which reduces the number of power divider network stages and grating lobe level of the array antenna after unit array. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of the present invention from the front view;

[0016] Figure 2 This is a three-dimensional structural diagram of the rear side of this utility model;

[0017] Figure 3 This is a front view of the waveguide array composed of this utility model;

[0018] Figure 4 The simulation results of the reflection coefficient of this utility model are shown in the figure.

[0019] Figure 5 The waveguide array constructed according to this invention has a horizontal axial radiation pattern at a frequency of 9.5 GHz.

[0020] Figure 6 This is the vertical axial pattern of the waveguide array of the component of this utility model at a frequency of 9.5 GHz.

[0021] The symbols for each component are as follows:

[0022] Waveguide housing 1, input port 11, output port 12, first matching step 13, second matching step 14, third matching step 15, distribution component 2, arc protrusion 21, suppression component 3. Detailed Implementation

[0023] The specific embodiments of this utility model are described below to enable those skilled in the art to understand this utility model. However, it should be understood that this utility model is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of this utility model as defined and determined by the appended claims, these changes are obvious. All utility model creations utilizing the concept of this utility model are within the scope of protection.

[0024] Example:

[0025] like Figure 1 and Figure 2As shown, a low-grid-lobe open waveguide antenna includes a waveguide housing 1, a distribution component 2, and a suppression component 3. The waveguide housing 1 is generally horn-shaped, with the small-diameter end being the input port 11 and the large-diameter end being the output port 12. The waveguide housing 1 is internally divided into three matching steps. The interior of the waveguide housing 1, from the input port 11 to the output port 12, includes a first matching step 13, a second matching step 14, and a third matching step 15. The corners of the side walls of the first matching step 13, the second matching step 14, and the third matching step 15 are all rounded. The sub-component 2 is used to divide the output port 12 of the waveguide housing 1 into multiple independent open waveguide radiation units. The sub-component 2 is cross-shaped and includes two intersecting grid bars. The grid bars are metal grid bars. The four ends of the two grid bars are fixedly connected to the inner wall of the output port 12 of the waveguide housing 1. The left and right side walls of the vertical grid bars are provided with arc protrusions 21. The arc protrusions 21 are symmetrically arranged about the intersection of the two grid bars. The suppression component 3 is located on the matching step near the output port 12 of the waveguide housing 1 and is connected to the sub-component 2. The extension direction of the suppression component 3 is the E-plane direction of the waveguide housing 1. The suppression component 3 includes two suppression metal blocks. The two suppression metal blocks are arranged opposite to each other at both ends of the grid bar with arc protrusions 21 and the bottom is fixedly located on the third matching step 15. The top of the suppression metal blocks is fixedly connected to the bottom surfaces of both ends of the grid bar with arc protrusions 21.

[0026] Impedance matching is achieved through a three-stage matching ladder, resulting in a simple structure and lower profile. Compared to a two-stage matching ladder, this method provides better impedance matching. By setting a distributor 2 at the output port 12 of the waveguide housing 1, the output port 12 is divided into multiple independent waveguide radiation units, reducing system weight and profile height, and decreasing antenna volume. Furthermore, using this invention as a waveguide array antenna reduces the number of power divider network stages. The suppression component along the E-plane of the waveguide housing reduces edge diffraction and lowers the grating lobe level of the array antenna after the unit is assembled into an array. Setting the distributor 2 in a cross shape enables a one-to-four power distribution network at the output port 12, dividing the radiation unit into independent small aperture units, achieving equal amplitude and in-phase radiation from the four open waveguide units. This simplifies the power divider network and improves aperture efficiency. The circular arc protrusions 21 on the vertical grating bars, in conjunction with the suppression component 3, help to homogenize the electric field of each independent small open waveguide radiation unit, reducing the grating lobe level of the antenna array after unit assembly.

[0027] The waveguide antenna of this invention was simulated using an open boundary, and the simulation results of the reflection coefficient are as follows: Figure 4 As shown, the reflection coefficient of this invention is less than -15dB within the 9.2-9.8GHz range, indicating that the matching effect of this invention is good.

[0028] like Figure 3 , Figure 5 and Figure 6 As shown, a waveguide array consists of sixteen low-grid-lobe open waveguide antennas arranged in a 4x4 array.

[0029] By arraying this invention into an array antenna, the number of power divider network stages of the array antenna can be effectively reduced.

[0030] When the operating frequency f = 9.5 GHz, the simulated radiation pattern of the waveguide array in two mutually perpendicular planes is as follows: Figure 5 and Figure 6 As shown, at 9.5 GHz, the gain of this planar waveguide array reaches 24.8 dBi, and the calculated aperture efficiency is 87.2%. The horizontal radiation pattern shows that the grating lobe level of the array is less than -17.3 dB outside ±15°.

[0031] The above results show that the present invention has advantages such as high gain, high aperture efficiency, compact structure, light weight, and low gate lobe level, and can be applied to confined space scenarios such as vehicle-mounted applications.

[0032] It should be noted that the vertical orientation in this article refers only to the orientation shown in the attached diagram and does not represent the actual orientation of the components.

Claims

1. A low-grid-lobe aperture waveguide antenna, characterized in that, include: The waveguide housing (1) is generally horn-shaped, with the small-diameter end being the input port (11) and the large-diameter end being the output port (12). The waveguide housing (1) is internally divided into at least three matching steps. Sub-component (2), fixedly disposed at the output port (12) of the waveguide housing (1), used to divide the output port (12) of the waveguide housing (1) into multiple independent open waveguide radiation units; The suppression element (3) is located on the matching step near the output port (12) of the waveguide housing (1) and connected to the distribution element (2). The suppression element (3) is a plate-shaped structure and extends in the direction of the E-plane of the waveguide housing (1).

2. The low-grid-lobe aperture waveguide antenna according to claim 1, characterized in that, The interior of the waveguide housing (1) includes a first matching step (13), a second matching step (14) and a third matching step (15) from the input port (11) to the output port (12).

3. The low-grid-lobe aperture waveguide antenna according to claim 2, characterized in that, The distribution component (2) is cross-shaped and includes two intersecting grid bars. The four ends of the two grid bars are fixedly connected to the inner wall of the output port (12) of the waveguide housing (1). The left and right side walls of the vertical grid bars are provided with arc protrusions (21), and the arc protrusions (21) are symmetrically arranged about the intersection of the two grid bars.

4. The low-grid-lobe aperture waveguide antenna according to claim 2, characterized in that, The suppressing component (3) includes two suppressing metal blocks, which are disposed opposite to each other at both ends of the grid strip with arc protrusions (21) and their bottoms are fixedly disposed on the third matching step (15). The top of the suppressing metal block is fixedly connected to the bottom surface of both ends of the grid strip with arc protrusions (21).

5. The low-grid-lobe aperture waveguide antenna according to claim 2, characterized in that, The corners of the side walls of the first matching step (13), the second matching step (14) and the third matching step (15) are all rounded.

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