A azimuth beam deflection antenna with special-shaped horn mouth

Abstract

The present invention discloses an azimuth plane beam deflection antenna with a special-shaped trumpet mouth, comprising a first antenna layer and a second antenna layer, wherein the first antenna layer is provided with a first trumpet mouth, a plurality of second trumpets mouths and a feeder network, the first trumpet mouth is provided on the upper side surface of the first antenna layer, the feeder network is provided on the lower side surface of the first antenna layer, one end of the plurality of second trumpets mouths is connected to the first trumpet mouth, and the other end of the plurality of second trumpets mouths is connected to the feeder network. The present invention directly regulates the radiation direction of electromagnetic waves through the shape and tilt angle of the trumpet mouth to obtain a stable directional pattern, and the antenna structure is simple, the loss is low, and the gain is large.

Description

Technical Field

[0001] The invention relates to a beam deflection antenna, in particular to an azimuth plane beam deflection antenna with a special-shaped horn mouth, belonging to the technical field of antennas. Background Art

[0002] The antenna is an important part of the millimeter wave radar system. It can detect objects within the field of view by transmitting and receiving electromagnetic waves. With the development of millimeter wave radar, in some applications, the radar needs to have a higher detection capability at a certain angle. This puts forward special requirements for the far-field radiation pattern of the antenna, that is, to have the highest gain at this specific angle and to achieve an asymmetric far-field radiation pattern. Compared with traditional microstrip antennas, waveguide antennas have obvious advantages in the millimeter wave frequency band of 76-81GHz, such as low loss, high gain, wide bandwidth and high isolation. The traditional way of achieving beam deflection through parasitic units is easily interfered by coupling between antenna arrays and is difficult to process.

[0003] For example, Chinese patent publication number CN114649661B discloses a waveguide with radiation slots and parasitic elements for asymmetric coverage. The device may include a waveguide for providing asymmetric coverage in an azimuth plane. The waveguide includes: a hollow channel containing a dielectric, and an array of radiation slots passing through a surface and operably connected to the dielectric. The waveguide includes an array of parasitic elements, which is positioned on or in the surface and deviates from the longitudinal side of the radiation slot array. The radiation slots and parasitic elements configure the described waveguide to focus the antenna radiation pattern, which provides asymmetric coverage to focus on a specific portion within the antenna field of view.

[0004] This solution uses coupling to achieve directional pattern focusing at a specific angle, but this method is easily affected by coupling between array elements. When multiple antenna units form an array, the originally designed focusing angle will be offset or even completely changed. In addition, parasitic elements and additional dielectric layers will increase the difficulty of antenna processing and manufacturing, increasing costs.

[0005] For example, Chinese patent publication number CN114784499A discloses a beam deflection antenna, antenna array, radar sensor and vehicle, including: a dielectric layer and a metal layer and a ground layer arranged on both sides of the dielectric layer. The metal layer also includes a first radiation patch and a feeder. In this technical solution, the feeder realizes biased feeding of the first radiation patch, and the current distribution on the first radiation patch is asymmetric, thereby realizing beam deflection while effectively reducing the size of the antenna.

[0006] This solution is based on a microstrip line beam deflection antenna. In the 76-81GHz frequency band, microstrip antennas have problems of high loss and low gain. The isolation between the elements of microstrip array antennas is poor. The resonant characteristics of microstrip antennas result in a narrow working bandwidth and the direction of each frequency is Figure 1 Poor consistency.

[0007] It can be seen that the prior art has the following defects:

[0008] 1. The method of using coupling to generate azimuth beam deflection has poor anti-interference performance, and the antenna pattern changes significantly after forming an array;

[0009] 2. Adding parasitic elements to the antenna surface to achieve beam deflection will increase processing difficulty and cost;

[0010] 3. The microstrip beam deflection antenna has narrow bandwidth, high loss and low gain. Summary of the invention

[0011] The technical problem to be solved by the present invention is to provide an azimuth plane beam deflection antenna with a special-shaped horn mouth, which can obtain a stable radiation pattern and high gain through a simple antenna structure.

[0012] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0013] The invention discloses an azimuth plane beam deflection antenna with a special-shaped trumpet mouth, comprising a first antenna layer and a second antenna layer, wherein the first antenna layer is provided with a first trumpet mouth, a plurality of second trumpets mouths and a feeder network, the first trumpet mouth is arranged on the upper side surface of the first antenna layer, the feeder network is arranged on the lower side surface of the first antenna layer, one end of the plurality of second trumpets mouths is connected to the first trumpet mouth, and the other end of the plurality of second trumpets mouths is connected to the feeder network.

[0014] Furthermore, the first bell mouth is a triangular pyramid cavity structure, the first side surface of the first bell mouth is flush with the upper side surface of the first antenna layer and the first side surface has the largest area, the second side surface and the third side surface of the first bell mouth are inverted triangles and are arranged inside the first antenna layer, and one end of the second bell mouth is connected to the second side surface of the first bell mouth.

[0015] Furthermore, the number of the second bell mouths is four, and the four second bell mouths are symmetrically arranged, the second bell mouth is a rectangular bell mouth, the four second bell mouths are distributed in a straight line on the second side surface of the first bell mouth along the length direction of the first bell mouth, and the cross-sectional area of ​​one end of the second bell mouth connected to the first bell mouth is larger than the cross-sectional area of ​​the other end of the second bell mouth.

[0016] Furthermore, an included angle θ1 between the second side surface of the first bell mouth and the horizontal plane is 35°, and an included angle θ2 between the third side surface of the first bell mouth and the horizontal plane is 20°.

[0017] Furthermore, the width w1 of the upper rectangular end faces of the four second bell mouths is 1.73 mm, the length l1 of the upper rectangular end faces of the two second bell mouths at the two ends is 2.37 mm, and the length l2 of the upper rectangular end faces of the two second bell mouths in the middle is 2.17 mm.

[0018] Furthermore, the feeder network includes an E-plane bent rectangular waveguide feeder, a matching step, a bent H-plane rectangular waveguide and an H-plane rectangular waveguide power divider matching protrusion, one end of the E-plane bent rectangular waveguide feeder is connected to one side of the matching step, the upper end of the matching step is connected to the lower end of the bent H-plane rectangular waveguide, the bent H-plane rectangular waveguide extends upward in a Y shape and completely covers the other end face of the four second horn mouths, and the H-plane rectangular waveguide power divider matching protrusion is located in the middle position of the upper end of the bent H-plane rectangular waveguide and between two second horn mouths located in the middle position among the four second horn mouths.

[0019] Furthermore, an antenna radiation slot is provided on the second antenna layer, and the antenna radiation slot is arranged vertically opposite to the rectangular waveguide feeder line bent on the E surface of the feeder network on the first antenna layer.

[0020] Compared with the prior art, the present invention has the following advantages and effects:

[0021] 1. The present invention adopts a two-stage special-shaped bell mouth scheme, and directly adjusts the radiation direction of the electromagnetic wave through the shape and inclination angle of the bell mouth to obtain a stable radiation pattern;

[0022] 2. The present invention uses a special-shaped bell mouth solution, which only requires appropriate design of the bell mouth shape, and can achieve beam deflection without adding other components or dielectric layers, thereby reducing the complexity of the structure, and reducing the processing difficulty and cost;

[0023] 3. The present invention uses a bent rectangular waveguide to perform center feeding on the special-shaped horn mouth, which can make the antenna have a very wide working bandwidth and at the same time make the antenna have the characteristics of low loss and high gain. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of an azimuth plane beam deflection antenna with a special-shaped horn mouth of the present invention.

[0025] Figure 2 is a schematic diagram of the first antenna layer of the present invention.

[0026] Figure 3 Schematic diagram of the second antenna layer of the present invention.

[0027] Figure 4It is a cross-sectional view of an azimuth plane beam deflection antenna with a special-shaped horn mouth of the present invention.

[0028] Figure 5 It is the azimuth plane direction diagram of the second bell mouth at different inclination angles according to the embodiment of the present invention.

[0029] Figure 6 It is a curve diagram of the relationship between the second horn inclination angle and the beam deflection angle in an embodiment of the present invention.

[0030] Figure 7 It is the azimuth plane radiation pattern of the embodiment of the present invention at 74-81 GHz.

[0031] Figure 8 It is the directional diagram of the elevation plane corresponding to 45° in the azimuth plane according to the embodiment of the present invention.

[0032] Fig. 9 It is a schematic diagram of reflection coefficient and maximum gain curve of an embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to elaborate on the technical scheme adopted by the present invention to achieve the predetermined technical purpose, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only partial embodiments of the present invention, rather than all embodiments, and the technical means or technical features in the embodiments of the present invention can be replaced without paying creative work. The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0034] like Figure 1 As shown, an azimuth plane beam deflection antenna with a special-shaped trumpet mouth of the present invention comprises a first antenna layer 1 and a second antenna layer 2, the first antenna layer 1 is provided with a first trumpet mouth 3, a plurality of second trumpet mouths 4 and a feeder network, the first trumpet mouth 3 is arranged on the upper side surface of the first antenna layer 1, the feeder network is arranged on the lower side surface of the first antenna layer 1, one end of the plurality of second trumpet mouths 4 is connected to the first trumpet mouth 3, and the other end of the plurality of second trumpet mouths 4 is connected to the feeder network.

[0035] The first bell mouth 3 is a triangular pyramid cavity structure. The first side surface of the first bell mouth 3 is flush with the upper side surface of the first antenna layer 1 and has the largest area. The second side surface and the third side surface of the first bell mouth 3 are inverted triangles and are arranged inside the first antenna layer 1. One end of the second bell mouth 4 is connected to the second side surface of the first bell mouth 3.

[0036] There are four second bell mouths 4, and the four second bell mouths 4 are symmetrically arranged. The second bell mouths 4 are rectangular bell mouths. The four second bell mouths 4 are distributed in a straight line on the second side surface of the first bell mouth 3 along the length direction of the first bell mouth 3. The cross-sectional area of ​​one end of the second bell mouth 4 connected to the first bell mouth 3 is larger than the cross-sectional area of ​​the other end of the second bell mouth 4, that is, the second bell mouth 4 is a rectangular bell mouth with a gradually increasing cross-sectional area.

[0037] The included angle θ1 between the second side surface of the first bell mouth 3 and the horizontal plane is 35°, and the second side surface of the first bell mouth 3 is also the upper end surface of the second bell mouth 4. The included angle θ2 between the third side surface of the first bell mouth 3 and the horizontal plane is 20°.

[0038] The width w1 of the upper rectangular end faces of the four second bell mouths 4 is 1.73 mm, the length l1 of the upper rectangular end faces of the two second bell mouths 4 at the two ends is 2.37 mm, and the length l2 of the upper rectangular end faces of the two second bell mouths 4 in the middle is 2.17 mm.

[0039] Figure 5 The corresponding azimuth plane radiation pattern under different first horn mouth tilt angles θ1, where the second horn mouth tilt angle θ2 is 20° and remains unchanged. It can be seen that the larger θ1 is, the larger the azimuth plane beam deflection angle is, and the higher the gain is. Figure 6 It is the relationship curve between θ1 and the azimuth beam deflection angle. As θ1 increases, the growth rate of the beam deflection angle gradually decreases and approaches 55°.

[0040] The feeder network includes an E-plane bent rectangular waveguide feeder 5, a matching step 6, a bent H-plane rectangular waveguide 7, and an H-plane rectangular waveguide power divider matching protrusion 8, wherein one end of the E-plane bent rectangular waveguide feeder 5 is connected to one side of the matching step 6, the upper end of the matching step 6 is connected to the lower end of the bent H-plane rectangular waveguide 7, the bent H-plane rectangular waveguide 7 extends upward in a Y shape and completely covers the other end face of the four second horn mouths 4, and the H-plane rectangular waveguide power divider matching protrusion 8 is located in the middle position of the upper end of the bent H-plane rectangular waveguide 7 and between the two second horn mouths 4 located in the middle position among the four second horn mouths 4. The matching step 6 is used to achieve impedance matching between the E-plane rectangular waveguide and the H-plane rectangular waveguide. The H-plane rectangular waveguide power divider matching protrusion 8 divides the signal into two paths to achieve center feeding. The offset of the bent H-plane rectangular waveguide 7 relative to the first radiation horn can adjust the excitation amplitude. The larger the absolute value of the offset, the larger the excitation amplitude. Low side lobes can be achieved by making the excitation amplitude conform to the Chebyshev weighted distribution.

[0041] The second antenna layer 2 is provided with an antenna radiation slot 9, which is arranged vertically opposite to the rectangular waveguide feeder line bent on the E surface of the feeder network on the first antenna layer.

[0042] like Figure 7 The figure shows the azimuth plane radiation pattern of the antenna of the present invention at 74-81 GHz, at which the tilt angle θ1 of the first horn is 35°, the maximum gain angle of the azimuth plane radiation pattern is about 45°, and the 3dB beam width is about 60°. The radiation pattern shapes of each frequency are basically the same. Figure 8 It is the radiation pattern of the elevation plane corresponding to 45° in azimuth plane, with side lobes below -18dB, 3dB beam width of 18°-20°, and 15dB beam width of 40°-50°.

[0043] like Fig. 9 As shown, the reflection coefficient of the antenna is less than -15dB at 75-81GHz, and the maximum gain is greater than 14dBi.

[0044] The present invention adopts a two-stage special-shaped bell mouth scheme, and directly regulates the radiation direction of the electromagnetic wave by the shape and inclination angle of the bell mouth to obtain a stable radiation pattern; the present invention uses the special-shaped bell mouth scheme, and only needs to properly design the shape of the bell mouth, and can realize beam deflection without adding other elements or dielectric layers, thereby reducing the complexity of the structure, and reducing the processing difficulty and cost; the present invention uses a bent rectangular waveguide to perform center feeding on the special-shaped bell mouth, so that the antenna has a very wide working bandwidth, and at the same time, the antenna has the characteristics of low loss and high gain.

[0045] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement made to the above embodiments without departing from the content of the technical solution of the present invention, based on the technical essence of the present invention, within the spirit and principles of the present invention, still fall within the protection scope of the technical solution of the present invention.

Claims

1. An azimuth beam deflection antenna with a special-shaped horn mouth, characterized in that: The invention comprises a first antenna layer and a second antenna layer, wherein the first antenna layer is provided with a first bell mouth, a plurality of second bell mouths and a feeder network, the first bell mouth is provided on the upper side of the first antenna layer, the feeder network is provided on the lower side of the first antenna layer, one end of the plurality of second bell mouths is connected to the first bell mouth, and the other end of the plurality of second bell mouths is connected to the feeder network; The first bell mouth is a triangular pyramid cavity structure, the first side surface of the first bell mouth is arranged flush with the upper side surface of the first antenna layer and has the largest area, the second side surface and the third side surface of the first bell mouth are arranged in an inverted triangle inside the first antenna layer, and one end of the second bell mouth is connected to the second side surface of the first bell mouth; There are four second bell mouths, and the four second bell mouths are symmetrically arranged. The second bell mouth is a rectangular bell mouth. The four second bell mouths are distributed in a straight line on the second side surface of the first bell mouth along the length direction of the first bell mouth. The cross-sectional area of ​​one end of the second bell mouth connected to the first bell mouth is larger than the cross-sectional area of ​​the other end of the second bell mouth.

2. The azimuth beam deflection antenna with a special-shaped horn according to claim 1, characterized in that: The included angle θ1 between the second side surface of the first bell mouth and the horizontal plane is 35°, and the included angle θ2 between the third side surface of the first bell mouth and the horizontal plane is 20°.

3. The azimuth beam deflection antenna with a special-shaped horn according to claim 2, characterized in that: The width w1 of the upper rectangular end faces of the four second bell mouths is 1.73 mm, the length l1 of the upper rectangular end faces of the two second bell mouths at the two ends is 2.37 mm, and the length l2 of the upper rectangular end faces of the two second bell mouths in the middle is 2.17 mm.

4. The azimuth beam deflection antenna with a special-shaped horn according to claim 1, characterized in that: The feeder network comprises an E-plane bent rectangular waveguide feeder, a matching step, a bent H-plane rectangular waveguide and an H-plane rectangular waveguide power divider matching protrusion, one end of the E-plane bent rectangular waveguide feeder is connected to one side of the matching step, the upper end of the matching step is connected to the lower end of the bent H-plane rectangular waveguide, the bent H-plane rectangular waveguide extends upward in a Y shape and completely covers the other end face of the four second horn mouths, and the H-plane rectangular waveguide power divider matching protrusion is located in the middle position of the upper end of the bent H-plane rectangular waveguide and is located between two second horn mouths located in the middle position among the four second horn mouths.

5. The azimuth beam deflection antenna with a special-shaped horn according to claim 4, characterized in that: The second antenna layer is provided with an antenna radiation slot, and the antenna radiation slot is arranged vertically opposite to the rectangular waveguide feeder line bent on the E surface of the feeder network on the first antenna layer.

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