TWI674703B - Wide beam high gain array antenna - Google Patents

Abstract

The invention provides a wide-beam high-gain array antenna including a first substrate, a ground layer, and a second substrate. The first substrate, the ground layer, and the second substrate have a laminated structure. A feeding network layer is disposed on one surface of the first substrate, and a main patch antenna and a parasitic patch antenna are disposed on one surface of the second substrate. Wherein, the main patch antenna includes a first metal through-hole, the first metal through-hole penetrates the first substrate, the ground layer, and the second substrate and is electrically connected to the feeding network layer; the parasitic patches The antennas each include a second metal through-hole that penetrates the second substrate and is electrically connected to the ground layer. The present invention utilizes a parasitic patch antenna with a metal through-hole to assist the main patch antenna, and superimposes two field types to increase the beam width, which can effectively improve the problem of insufficient antenna beam width, and meets the requirements of automotive antenna beam width.

Description

Wide beam high gain array antenna

The technology of the present invention relates to the field of antennas, and particularly to an anti-collision radar array antenna with a wide beam and high gain.

With the development of the times and social progress, the number of cars is increasing, traffic accidents are increasing, and people pay more attention to vehicle safety. Give the vehicle a collision warning or active collision avoidance function, which can effectively reduce accidents and improve vehicle safety. Therefore, the vehicle's forward collision warning systems (FCWS), forward collision avoidance systems (FCAS) ), Adaptive cruise control (ACC) and other vehicle safety technologies have developed rapidly in recent years. The common point of the above systems is to measure the distance, relative speed, and relative azimuth between the host vehicle and the target workshop through the vehicle collision avoidance radar, and transmit it to the control system. In recent years, advanced driver assistance systems (ADAS) have gradually become one of the smart vehicle technologies actively developed by car manufacturers. At present, ADAS is the most important detection field, including the introduction of photographic lenses in the front, side and rear of the vehicle, Sensors such as microwave radar or laser radar capture real-time road information to assist driving judgment.

Automotive anti-collision radar mostly uses microstrip patch antennas as sensors to detect the distance and direction in the workshop. However, the gain of the patch unit antenna is about 4 ~ 7 dBi, and its beam width is mostly 70 ° ~ 90 ° Compared with the ideal gain of 10 dBi and the ideal beam width of 120 °, it is still insufficient, so it has the disadvantages of insufficient gain and insufficient beam width in terms of electrical properties. In order to improve the above-mentioned shortcomings, existing literature has proposed the use of an antenna array (Antenna array) to increase the gain, and on the other hand, a parasitic element can be used to widen the beam width. Or use a lower dielectric constant plate, reduce the ground plane, or increase the substrate size to widen the beam. However, reducing the ground plane or increasing the substrate area will also reduce the gain. If a metal interface wall is added below the ground plane, the beam can be widened by affecting the field distribution around the main patch, but this method requires additional processing, which will increase the production cost and antenna size. Therefore, the current design of anti-collision radar antennas for vehicles still has room for improvement.

The main purpose of the present invention is to provide a wide-beam high-gain array antenna, which can effectively improve the problem of insufficient antenna beam width, and meets the requirements of automotive antenna beam width. In order to achieve the above object, the present invention adopts the following technical means to achieve it. Among them, the present invention provides a wide beam high gain array antenna including: a first substrate, a feeding network layer, a ground layer, and a second substrate. , At least one main patch antenna and a plurality of parasitic patch antennas. The feeding network layer is disposed on a surface of the first substrate and is used for telecommunication connection with a signal source. The ground layer is disposed on the other surface of the first substrate, and one surface of the second substrate is connected to the ground layer. The main patch antenna is disposed on the other surface of the second substrate, and the parasitic patch antennas are disposed on both sides of the main patch antenna and a first distance from the main patch antenna. The main patch antenna includes a first metal through-hole, the first metal through-hole penetrates the first substrate, the ground layer, and the second substrate, and is respectively connected to the feeding network layer and the main patch antenna. For telecommunication connection, each of the parasitic patch antennas includes a second metal through-hole, the second metal through-hole penetrates the second substrate, and is electrically connected to the ground layer and the parasitic patch antenna, respectively.

In a preferred embodiment of the present invention, the main patch antenna and the parasitic patch antennas are arranged on the second substrate along a first direction.

In a preferred embodiment of the present invention, the shape of the main patch antenna and the parasitic patch antennas are rectangular.

In a preferred embodiment of the present invention, the main patch antenna and the parasitic patch antenna are arranged in an array, and two sides of each of the main patch antennas respectively include two of the parasitic patch antennas.

In a preferred embodiment of the present invention, the first metal through hole is a hollow metal cylinder.

In a preferred embodiment of the present invention, the second metal through hole is a hollow metal cylinder.

In a preferred embodiment of the present invention, the array antenna includes a plurality of main patch antennas, and each of the main patch antennas has four of the parasitic patch antennas.

In a preferred embodiment of the present invention, the feeding network layer includes a plurality of metal lines, an impedance converter, a power divider, and a signal source end line.

In a preferred embodiment of the present invention, one end of the metal lines is connected to the first metal through-hole telecommunications, one end of the impedance converter is connected to the other end of the metal lines, and one end of the power divider is connected to the impedance. The other end of the converter is connected by telecommunications, and the signal source end line is connected with the other end of the power divider and the signal source by telecommunications.

In a preferred embodiment of the present invention, the line width of the metal lines is 0.5 mm, the line width of the impedance converter is 2 mm, the line width of the power divider is 1.8 mm, and the width of the signal source side line is 0.5 mm.

The technical means and structure adopted in the present invention are described in detail below with reference to the embodiments of the present invention. The features and functions are as follows, but it should be noted that the content does not limit the present invention.

Please refer to FIG. 1, FIG. 2 and FIG. 3 at the same time, which are structural schematic diagrams, cross-sectional schematic diagrams, and partial enlarged schematic diagrams of the preferred embodiment of the wide beam high gain array antenna of the present invention. The invention provides a wide-beam high-gain array antenna, which includes a first substrate 1, a feeding network layer 2, a ground layer 3, a second substrate 4, at least one main patch antenna 5, and a plurality of parasitic patches. Antenna 6.

The first substrate 1 is a laminated substrate having the advantages of low dielectric constant, low loss factor, stable frequency and temperature, etc., and is suitable as a carrier plate for a patch antenna and a feeding network.

The feeding network layer 2 is disposed on one surface 11 of the first substrate 1, the ground layer 3 is disposed on the other surface of the first substrate 1, and one surface of the second substrate 4 is connected to the ground layer 3 . The array antenna of the present invention has a double-layer substrate structure, and a metal ground layer is provided between the first substrate 1 and the second substrate 4.

The main patch antenna 5 is disposed on the other surface 41 of the second substrate 4. Each of the main patch antennas 5 includes a first metal through-hole 51, and the first metal through-hole 51 penetrates the first substrate. 1. The ground layer 3 and the second substrate 4 are electrically connected to the feeding network layer 2 and the main patch antenna 5, respectively. The first metal through-hole 51 is a hollow metal cylinder or a solid metal cylinder, which penetrates the first substrate 1, the ground layer 3, and the second substrate 4 and is electrically connected to the feeding network layer 2 to transmit the array antenna. Signal. The present invention does not limit the relative positional relationship between the first metal through-hole 51 and the main patch antenna 5, and it can be connected to the center of the main patch antenna 5. However, considering the mutual coupling effect of the radiation edges, the first The position of the metal through hole 51 will affect the input impedance, so the position of the first metal through hole 51 can also be adjusted to achieve the required input impedance.

Please refer to FIGS. 4 and 5, which are schematic diagrams of a feeding network layer and a patch antenna of a preferred embodiment of a wide beam high gain array antenna according to the present invention. In an embodiment of the present invention, the array antenna includes a plurality of main patch antennas 5, each of the main patch antennas 5 has four parasitic patch antennas 6, and the feeding network layer 2 includes The plurality of metal lines 21, an impedance converter 22, a power divider 23, and a signal source end line 24. One end of the metal lines 21 is electrically connected to the first metal through holes 51, one end of the impedance converter 22 is electrically connected to the other end of the metal lines 21, and one end of the power divider 23 is connected to the impedance converter 22. The other end is connected by telecommunications, and the signal source end line 24 is connected with the other end of the power divider 23 and the signal source by telecommunications. Preferably, the line width of the metal lines 21 is 0.5 mm, the line width of the impedance converter 22 is 2 mm, the line width of the power divider 23 is 1.8 mm, and the width of the signal source line 24 is 0.5. Mm. The feed network layer 2 of the present invention is connected in a series-parallel feed network. The metal lines 21, the impedance converter 22, and the first metal through holes 51 are connected in parallel. The signal source, the signal source end line 24, The power dividers 23 are connected in series.

The parasitic patch antenna 6 and the main patch antenna 5 are located on the same layer of medium to increase the bandwidth and gain of the main patch antenna 5. The parasitic patch antenna 6 couples energy radiation by being adjacent to the main patch. Since the beam width required by the anti-collision radar antenna is quite wide, in order to further increase the beam width of the array antenna, the parasitic patch antenna 6 is set on the main patch. On both sides of the antenna 5, the current phase of the parasitic element is opposite to that of the main patch antenna 5, and a canceling effect is generated, thereby reducing the effective radiation aperture and increasing the beam width.

Each of the parasitic patch antennas 6 includes a second metal through-hole 61 that penetrates the second substrate 4 and is electrically connected to the ground layer 3 and one of the parasitic patch antennas 6 respectively. The second through-hole 61 is a hollow metal cylinder or a solid metal cylinder.

In one embodiment of the present invention, the positions of the second metal through-holes 61 are designed in the middle of the parasitic patch antennas 6 with a radius of 0.2 mm and the same height as the thickness of the second substrate 4.

In this embodiment, the shapes of the main patch antenna 5 and the parasitic patch antennas 6 are rectangular, but are not limited thereto. The present invention does not limit the number of the main patch antennas 5, in order to improve the overall gain of the array antenna, the number of the main patch antennas 5 can be increased according to actual needs, such as four, eight, and so on. In the preferred embodiment, the array antenna includes eight main patch antennas 5, and each main patch antenna 5 has four parasitic patch antennas 6. The main patch antennas 5 and the parasitic patch antennas 6 are arranged on the second substrate 4 along a first direction. The main patch antennas 5 and the parasitic patch antennas 6 are arrayed. Each side of each of the main patch antennas 5 includes two of the parasitic patch antennas 6, preferably, the parasitic patch antennas 6 are arranged along the first direction on the main patch antenna 5. On both sides. The main patch antenna 5 and the isoparasitic patch antenna 6 are separated by a horizontal distance d ₁ , and the two parasitic patch antennas 6 on the same side are separated by a distance d ₂ . Because the frequency response degree changes with the horizontal distance d ₁ , the smaller the horizontal distance d ₁ is, the stronger the coupling is, and a better impedance matching can be obtained, otherwise it is worse.

It is worth mentioning that the length L and width W of the parasitic patch antenna 6 have a significant impact on the resonance frequency and impedance matching. When the length is larger, it will move to low frequencies, and vice versa. After the resonance frequency is determined, impedance matching can be performed by adjusting the width of the parasitic patch antenna 6.

Please refer to FIGS. 6 and 7, which are S11 (Return Loss) frequency response diagrams and radiation field diagrams of the wide beam high gain array antenna of the present invention, respectively. According to the S11 frequency response diagram, it can be seen that the center frequencies of the simulation and measurement are located at 24 GHz and 23.7 GHz, respectively. The measurement results show that the frequency tends to be low, and the analog and measurement ratio bandwidths are 16.2% and 16.9%, respectively. According to the radiation field pattern, it can also be seen that the measured gain value is about 11 dBi, the E-plane measurement beam width is about 150 °, and the H-plane measurement beam width is about 10 °, which meets the requirements of automotive antenna beam width. .

In summary, a wide beam high gain array antenna provided by the present invention is provided with a parasitic patch antenna with metal through holes to assist the main patch antenna, and is combined with a series-parallel feeder network to form an antenna array. The superposition of the patch antenna field pattern increases the beam width, which can effectively improve the problem of insufficient antenna beam width, and meets the requirements of automotive antenna beam width.

The above descriptions are only examples of the present invention, and thus do not limit the implementation and protection scope of the present invention. For those skilled in the art, they should be able to realize that equivalent substitutions and Obvious changes should be included in the protection scope of the present invention.

1‧‧‧ the first substrate

2‧‧‧Feed network layer

21‧‧‧Metal circuit

22‧‧‧Impedance Converter

23‧‧‧ Power Divider

24‧‧‧Signal source line

3‧‧‧ ground plane

4‧‧‧ second substrate

5‧‧‧Main patch antenna

51‧‧‧The first metal through hole

6‧‧‧ Parasitic patch antenna

61‧‧‧Second metal through hole

11, 41‧‧‧ surface

d ₁ ‧‧‧horizontal spacing

d ₂ ‧‧‧ pitch

L‧‧‧ length

W‧‧‧Width

FIG. 1 is a schematic structural diagram of a preferred embodiment of a wide beam high gain array antenna according to the present invention. FIG. 2 is a schematic cross-sectional view of a preferred embodiment of a wide beam high gain array antenna according to the present invention. FIG. 3 is a partially enlarged schematic diagram of a preferred embodiment of a wide beam high gain array antenna according to the present invention. FIG. 4 is a schematic diagram of a feeding network layer of a preferred embodiment of a wide beam high gain array antenna according to the present invention. FIG. 5 is a schematic diagram of a patch antenna according to a preferred embodiment of the wide beam high gain array antenna of the present invention. FIG. 6 is an S11 frequency response diagram of a preferred embodiment of the wide beam high gain array antenna of the present invention. FIG. 7 is a radiation pattern diagram of a preferred embodiment of a wide beam high gain array antenna according to the present invention.

Claims (9)

A wide-beam high-gain array antenna includes a first substrate and a feeding network layer disposed on a surface of the first substrate for telecommunication connection with a signal source. The feeding network layer includes a plurality of bars. A metal line, and the line width of the metal line is 0.5 mm, the line width of the impedance converter is 2 mm, the line width of the power divider is 1.8 mm, and the width of the signal source side line is 0.5 mm; a ground plane Is disposed on the other surface of the first substrate; a second substrate having a surface connected to the ground layer; at least one main patch antenna is disposed on the other surface of the second substrate; and a plurality of Parasitic patch antennas are disposed on both sides of the main patch antenna and are at a first distance from the main patch antenna; wherein the main patch antenna includes a first metal through-hole, the first metal through-hole The first substrate, the ground layer, and the second substrate pass through and are electrically connected to the feeding network layer and the main patch antenna, respectively. The parasitic patch antennas each include a second metal through hole, and the second Metal through hole The second substrate passes through the second substrate and is electrically connected to the ground layer and the parasitic patch antenna, respectively. The wide-beam high-gain array antenna according to item 1 of the patent application scope, wherein the main patch antenna and the parasitic patch antennas are arranged on the second substrate along a first direction. The wide beam high gain array antenna according to item 1 of the scope of patent application, wherein the shape of the main patch antenna and the parasitic patch antennas are rectangular. The wide-beam high-gain array antenna according to item 1 of the patent application range, wherein The main patch antenna and the parasitic patch antenna are arranged in an array, and two sides of each main patch antenna include two of the parasitic patch antennas respectively. The wide-beam high-gain array antenna according to item 1 of the patent application scope, wherein the first metal through-hole is a hollow metal cylinder or a solid metal cylinder. The wide-beam high-gain array antenna according to item 1 of the patent application scope, wherein the second metal through-hole is a hollow metal cylinder or a solid metal cylinder. The wide beam high gain array antenna according to item 1 of the patent application scope, wherein the array antenna includes a plurality of main patch antennas, and each of the main patch antennas has four of the parasitic patch antennas. The wide beam high gain array antenna according to item 7 of the patent application scope, wherein the feeding network layer further includes an impedance converter, a power divider, and a signal source end line. The wide-beam high-gain array antenna according to item 8 of the scope of the patent application, wherein one end of the metal lines is connected to the first metal through-hole telecommunications, and one end of the impedance converter is connected to the other end of the metal lines. One end of the power divider is electrically connected to the other end of the impedance converter, and the signal source line is connected to the other end of the power divider and the signal source.