WO2018233263A1

WO2018233263A1 - Vehicle rear side radar antenna array and planar array antenna

Info

Publication number: WO2018233263A1
Application number: PCT/CN2017/118385
Authority: WO
Inventors: 高金瑞; 周立夫
Original assignee: 惠州市德赛西威汽车电子股份有限公司
Priority date: 2017-06-23
Filing date: 2017-12-25
Publication date: 2018-12-27
Also published as: CN107453043A

Abstract

The present invention relates to a vehicle rear side radar antenna array, comprising a plurality of first antenna units and a feed structure, the plurality of first antenna units forming an in-line array and being connected by a microstrip; the feed structure being arranged in the center of symmetry of the plurality of antenna units; and each antenna unit having a first groove at the front end and a second groove at the rear end. A plurality of in-line antenna arrays constitute a planar array antenna having a transmitting antenna portion and a receiving antenna portion. The beneficial technical effects of the present invention are as follows: 1) a traveling wave series-fed microstrip line array is adopted to widen the working bandwidth, with a structure that is compact and easy to integrate into a sensor; 2) emission direction pattern detection capability is optimized according to an approximate super-cosecant squared distribution, high gain is provided in directions needing long-distance detection, and reduced gain is provided in directions without the need for long-distance detection, better meeting detection capability requirements of radar systems; and 3) by using a receiving antenna scheme of three antennas with long and short baselines, sufficient accuracy of angle measurements can be ensured.

Description

Rear side radar antenna array and antenna array

Technical field

The present invention relates to the field of antenna technologies, and in particular, to a rear side radar antenna array and an antenna array.

Background technique

The anti-collision function behind the car side is to detect obstacles in the rear side area and provide early warning to help the driver take emergency measures.

The side rear anti-collision function mainly includes blind spot detection, lane change assist, RCTA and other functions. Microstrip antennas are especially suitable for automotive-borne microwave radars due to their low cost and low profile. In order to save size and reduce losses, the array is usually formed in the form of a series feed, but the commonly used series feed antenna is a resonant antenna, which has the disadvantage of narrow bandwidth. If RO4350 sheet is used, the thickness is 0.254mm and the dielectric constant is 3.66. At this time, a single multi-unit antenna can only achieve a bandwidth of about 300M. For sensors with a working frequency range of 24G to 24.25G, the working bandwidth is close to the antenna bandwidth, which is bound to bring quality control challenges for large-scale production.

For automotive anti-collision radar, angle measurement, ranging and speed measurement constitute three functions of its function, in which the angle measurement can be compared with the amplitude, phase or spectrum analysis method. Because of the simplicity of the phase angle, it is a commonly used angle measurement technique. The larger the baseline, the higher the accuracy of the angle measurement, but the pitch is greater than 0.5λ.

1. Although the series-fed resonant antenna has a compact structure, it also has the disadvantage of narrow bandwidth. Although the feed can achieve wider bandwidth, it also has the disadvantages of large feeder loss and relatively large size.

2. If the power coverage of the anti-collision radar system on the side rear is not ideal, it will cause unnecessary clutter signals to enter the system in addition to the useful signals, increasing the difficulty of the back-end signal processing.

3. For the target detection of the vehicle anti-collision radar system, in addition to the speed and distance, the target orientation is also a key indicator. If the single-baseline angle measurement scheme is adopted, only the small spacing method can be adopted. The disadvantages of high requirements and relatively low precision.

Summary of the invention

In order to solve the above technical problems, the present invention provides a rear side radar antenna unit, an antenna array, and an antenna array.

A rear side radar antenna array of a vehicle includes a plurality of first antenna units and a feeding structure; a plurality of the first antenna units form a word array and are connected by a microstrip; the feeding structure is disposed at the plurality of a symmetric center of the antenna elements; each of the antenna elements includes a front end adjacent to the feed structure and a rear end remote from the feed structure, the front end having a first groove; a rear end of the antenna unit There is a second groove.

Further, the first antenna unit is disposed on a first surface of the circuit board, and the feeding structure is disposed on a second surface opposite to the first surface and connected to the microstrip through a plurality of conductive vias.

Further, a plurality of the conductive vias constitute a quasi-coaxial mechanism.

Further, the second antenna unit further includes two second antenna units respectively disposed at two ends of the array of the plurality of the first antenna units and connected to the microstrip, and the front end of the second antenna unit is first Groove.

Further, the middle portion of the microstrip is provided with a curved portion.

In addition, the present invention also provides an automotive side rear radar antenna array, comprising a plurality of in-line antenna arrays disposed on a first surface of the circuit board and a feed network disposed on the second surface of the circuit board;

The plurality of in-line antenna arrays respectively constitute a transmitting antenna portion and a receiving antenna portion; the transmitting antenna portion includes five in-line antenna arrays disposed in parallel; a spacing between each of the in-line antenna arrays is a wavelength Half of it.

Further, the feed network includes a trunk line and a branch line connected between each of the in-line antenna arrays; and the main line and each of the branch lines are provided with an impedance matching portion.

Further, the branch line includes a first branch line and a second branch line, and the first in-line antenna array, the second in-line antenna array, and the third in-line antenna array in the five in-line antenna arrays are sequentially Accessing the first trunk line; the fourth in-line antenna array and the fifth in-line antenna array accessing the second trunk line at a time; between the first in-line antenna array and the second in-line antenna array The first trunk line is provided with a first phase-modulating bent portion; the first trunk line between the second in-line antenna array and the third in-line antenna array is provided with a second phase-modulating bent portion; The second trunk line between the four in-line antenna array and the fifth in-line antenna array is provided with a third phase modulation bent portion;

Further, the receiving antenna portion includes a sixth in-line antenna array, a seventh in-line antenna array, and an eighth in-line antenna array disposed in parallel; between the sixth in-line antenna array and the seventh in-line antenna array The spacing between the seventh in-line antenna array and the eighth in-line antenna array is 2.5 times the operating wavelength;

Preferably, the in-line antenna array is the antenna array disclosed in the present invention.

The beneficial technical effects of the present invention are as follows:

1) The traveling wave series feeding microstrip line array can achieve a wider working bandwidth, and the structure is compact and easy to integrate into the sensor.

2) Optimize the transmission pattern detection ability according to the distribution of the approximate super-sector squared. When it is necessary to detect the far azimuth and high gain, the gain is reduced in the azimuth without the need of long-distance detection, which better satisfies the radar system's detection power. demand.

3) Through the receiving antenna scheme of 3 antennas with long and short baselines, sufficient angle measurement accuracy can be ensured.

DRAWINGS

1 is a schematic diagram of an antenna array in

Embodiment

1 or 2 of the present invention.

2 is a schematic structural view of an antenna array in Embodiment 2 of the present invention.

3 is a schematic diagram of a transmitting antenna section of a transmitting antenna according to Embodiments 2 and 4 of the present invention.

4 is a diagram showing the return loss of the antenna array in Embodiment 1 of the present invention.

FIG. 5 is a graph showing the variation of the amplitude of the sidelobe of the antenna array according to the frequency in the first embodiment of the present invention.

Fig. 6 is a view showing an E-plane and a H-plane of the antenna array in the first embodiment of the present invention.

Fig. 7 is a view showing an E-plane and a H-plane of the antenna array in the fourth embodiment of the present invention.

Wherein, the transmitting antenna portion is 1; the receiving antenna portion is 2; the first in-line antenna array is 10; the second in-line antenna array is 20; the third in-line antenna array is 30; and the fourth in-line antenna array is 40. The fifth in-line antenna array is 50; the sixth in-line antenna array is 60; the seventh in-line antenna array is 70; the eighth in-line antenna array is 80; the first antenna unit is 11, and the second antenna unit is 12. , the microstrip is 13; the first groove is 14; the second groove is 15; the conductive via is 16; the bent portion is 17; the feed network is 90; the first impedance matching portion is 91; and the second impedance matching portion is 92; the third impedance matching portion is 93; the fourth impedance matching portion is 94; the fifth impedance matching portion is 95; the first phase modulation bending portion is 96; and the second phase modulation bending portion is 97; The phase bend is 98.

Detailed ways

The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings, in which the advantages and features of the invention are more readily understood by those skilled in the art.

Example 1:

The embodiment provides an antenna array, which is applied to the rear side of the automobile radar and is a component of the rear side radar antenna array of the automobile. Since the direction of the rear side radar detection of the automobile is strong, the radar range is The shape needs to be more precise. An antenna array as a basic unit needs to have low side lobes and a wide bandwidth, as shown in FIG. There are a plurality of first antenna elements 11 and a feed structure. The first antenna unit 11 and the second antenna unit 12 are both square plate-like structures, which may be composed of a copper-clad layer. Above the arrangement, the plurality of first antenna elements 11 are arranged in a word shape to form a word array. A feed connection is achieved between the respective first antenna elements 11 by means of the microstrips 13. The feed is ultimately made by a feed structure that is placed at the center of the array of words. In order to achieve adjustment of the power distribution of each antenna unit, the signal side lobes of the antenna unit are depressed. Therefore, it is necessary to perform grooving at a specific position of the first antenna unit 11.

In this embodiment, in terms of the slotting method, for the convenience of description, we define the component position of the first antenna unit 11, and define one end of the first antenna unit 11 near the feeding structure as a front end, and one end away from the feeding structure is defined as rear end. The front end and the rear end of the first antenna unit 11 are all slotted, the groove opened at the front end is the first groove 14, and the groove opened at the rear end is the second groove 15. The first recess 14 and the second recess 15 are both open at the center of the end such that the slot is the junction of the microstrip.

The opened groove is preferably a rectangular groove, which has two technical indexes, namely width and depth, which affect the power distribution of the antenna array, thereby adjusting the beam shape of the H-plane emission direction.

In order to further reduce the side lobes, two second antenna units 12 are arranged, which are respectively arranged at the rear end of the first antenna unit 11, and are also fed through the microstrips so that the antenna unit as a whole remains one. Word array. Moreover, the second antenna unit 12 is only provided with the first groove 14, and the installation position and the width and depth requirements are the same as the first groove 14 of the first antenna unit 11. The return loss plot of the antenna array and the sidelobe level versus frequency curve are shown in Figures 4 and 5.

In terms of the feed structure, the feed structure is disposed at the center of symmetry of the plurality of antenna elements. Specifically, the first antenna unit 11 and the second antenna unit 12 are both disposed on the first surface of the circuit board, and the main portion of the feed structure is disposed on the second surface opposite to the first surface of the circuit board. The feed structure also includes conductive vias 16 disposed on the circuit board and through the circuit board. The conductive vias 16 are used to connect the antenna elements to the feed structure.

The conductive vias 16 in this embodiment are disposed at the center of symmetry of the constituent word arrays of the first antenna unit 11 and the second antenna unit 12. One end is connected to the main body of the feed structure, and the other end is connected to the microstrip 13 and also connected to the ground end of the antenna array.

In addition, the number of the conductive vias 16 may be multiple. The number of the conductive vias 16 used in this embodiment is five, and the plurality of conductive vias 16 constitute a quasi-coaxial structure, specifically, four conductive vias therein. 16 is squared, and the fifth conductive via 16 is disposed at the geometric center of the center of the relief.

In order to adjust the phase of the waveform, the middle portion of the microstrip, that is, near the conductive via 16 is provided with a bent portion 17, which may be formed in an "S" shape, thereby performing phase adjustment to achieve shaping.

In this embodiment, the number of the first antenna units 11 and the number of the second antenna units 12 are both even, and the number of the first antenna units 11 is eight, and the number of the second units is two. Finally, a 10-cell series-fed traveling wave microstrip antenna array is constructed together. The E-plane and H-plane directions of the antenna array are shown in Fig. 6.

Example 2:

The embodiment further provides an array of rear side radar antennas of the automobile, which can mainly implement functions such as blind spot detection, lane change assistance and RCTA. As shown in Figure 2 and Figure 3. The transmitting antenna unit 1 and the receiving antenna unit 2 are provided. Specifically, it includes a plurality of in-line antenna arrays disposed on the first surface of the circuit board and a feed network 90 disposed on the second surface of the circuit board.

Both the transmitting antenna unit 1 and the receiving antenna unit 2 are composed of a plurality of in-line antenna arrays.

In terms of the transmitting antenna portion 1, five in-line antenna arrays are arranged in parallel, and the spacing between each in-line antenna array is half of the wavelength, eventually forming a transmitting antenna array.

Further, in terms of the feeder path of the transmitting antenna section 1, it is constituted by a conductive micro-belt including a trunk line and a branch trunk. The trunk line is used to connect an external feed source, and the branch line is connected between the trunk line and the in-line antenna array.

In this embodiment, the feeding network 90 of the transmitting antenna portion 1 includes two branch lines, and five in-line antennas are feed-connected through the first branch line and the second branch line. For convenience of description, the five in-line antenna arrays are respectively defined as a first in-line antenna array 10, a second in-line antenna array 20, a third in-line antenna array 30, a fourth in-line antenna array 40, and a fifth. In-line antenna array 50.

The first in-line antenna array 10, the second in-line antenna array 20, and the third in-line antenna array 30 are disposed on the first branch line, and the three are sequentially connected to the first branch line. The fourth in-line antenna array 40 and the fifth in-line antenna array 50 are disposed on the second branch line, and the relationship is also in a parallel relationship.

In order to better adjust the power relationship between the in-line antenna arrays, the main line and each branch line are provided with impedance matching portions. The power distribution can be adjusted by adjusting the impedance impedance matching section. In this embodiment, the impedance matching unit adjusts the impedance by widening the microstrip.

In addition, in order to achieve phase adjustment, the beam is shaped. The first branch line between the first in-line antenna array 10 and the second in-line antenna array 20 is provided with a first phase-modulating bent portion 96; the second in-line antenna array 20 and the third in-line antenna array 30 The first trunk line is provided with a second phase-adjusting bent portion 97; the second branch line between the fourth in-line antenna array 40 and the fifth in-line antenna array 50 is provided with a third phase-adjusting bent portion 98.

In this embodiment, the in-line antenna array uses the antenna array in Embodiment 1.

Example 3:

The difference between this embodiment and the embodiment 2 is that, as shown in FIG. 2, the receiving antenna portion 2 in this embodiment includes a sixth in-line antenna array 60, a seventh in-line antenna array 70, and an eighth in-line array arranged in parallel. Antenna array 80. The spacing between the sixth in-line antenna array 60 and the seventh in-line antenna array 70 is 0.5 times the operating wavelength. The distance between the seventh in-line antenna array 70 and the eighth in-line antenna array 80 is 2.5 times the operating wavelength. The receiving antenna section 2 forms a 3-antenna scheme of a long and short baseline, ensuring accurate angle measurement with high precision.

In the feeding network of the receiving antenna unit 2, the feeding is specifically performed by a separate feeding microstrip line, that is, the microstrips directly connected to the feeding power source respectively respectively pair the sixth in-line antenna array 60 and the seventh in-line The antenna array 70 and the eighth in-line antenna array 80 are fed, and the mid-stage feeding mode is adopted to ensure that the upper and lower antenna units of each antenna array are fed in the same direction by phase shifting by 180 degrees.

Example 4:

The difference between this embodiment and the third embodiment is that, as shown in FIG. 3, the specific matching relationship between the impedance matching portion and the phase-modulating bending portion in the feeder circuit of the transmitting antenna portion 1 is as follows. a first impedance matching portion 91 disposed on the branch of the first in-line antenna array 10, a third impedance matching portion 93 disposed on the third in-line antenna unit 30, and a fifth impedance matching disposed in the fifth in-line antenna unit The parameters and shapes of the three parts are the same.

The fourth impedance matching portion 94 provided in the fourth in-line antenna unit and the second impedance matching portion 92 provided in the second in-line antenna unit are mirror-symmetrical.

Finally, the transmission antenna portion 1 is shown in the H-plane direction as shown in FIG.

The embodiments of the present invention have been described in detail above with reference to the drawings, but the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the invention. Kind of change.

Claims

An automobile side rear radar antenna array, comprising: a plurality of first antenna units and a feeding structure; a plurality of the first antenna units forming a word array and connected by a microstrip; the feeding structure setting At a center of symmetry of the plurality of antenna elements; each of the antenna elements includes a front end adjacent to the feed structure and a rear end remote from the feed structure, the front end having a first groove; the antenna The rear end of the unit has a second recess.
The rear side radar antenna array according to claim 1, wherein the first antenna unit is disposed on a first surface of the circuit board, and the feeding structure is disposed on a second surface opposite to the first surface The surface is connected to the microstrip through a plurality of conductive vias.
The automotive side rear radar antenna array according to claim 1, wherein the plurality of conductive vias constitute a quasi-coaxial mechanism.
The rear side radar antenna array of a vehicle according to claim 1, further comprising two second antenna units respectively disposed at two ends of the array formed by the plurality of the first antenna units and the micro The belt is connected, and the front end of the second antenna unit is provided with a first groove.
The automotive side rear radar antenna array according to claim 1, wherein a middle portion of the microstrip is provided with a bent portion.
An automotive side rear radar antenna array, comprising: a plurality of in-line antenna arrays disposed on a first surface of the circuit board; and a feed network disposed on the second surface of the circuit board;

The plurality of in-line antenna arrays respectively constitute a transmitting antenna portion and a receiving antenna portion; the transmitting antenna portion includes five in-line antenna arrays disposed in parallel; a spacing between each of the in-line antenna arrays is a wavelength Half of it.
The rear side radar antenna array according to claim 6, wherein said feed network comprises a main line and a branch line connected between each of said in-line antenna arrays; said main line and each An impedance matching portion is provided on the branch line.
The rear side radar antenna array according to claim 1, wherein the branch line comprises a first branch line and a second branch line, and the first in-line antenna of the five in-line antenna arrays The array, the second in-line antenna array, and the third in-line antenna array are sequentially connected to the first branch line; the fourth in-line antenna array and the fifth in-line antenna array are once connected to the second branch line; The first trunk line between the first in-line antenna array and the second in-line antenna array is provided with a first phase-modulating bend; the first between the second in-line antenna array and the third in-line antenna array A trunk line is provided with a second phase-modulating bent portion; and a second trunk line between the fourth in-line antenna array and the fifth in-line antenna array is provided with a third phase-modulating bent portion;
The rear side radar antenna array according to claim 6, wherein the receiving antenna portion comprises a sixth in-line antenna array, a seventh in-line antenna array, and an eighth in-line antenna array arranged in parallel; The spacing between the sixth in-line antenna array and the seventh in-line antenna array is 0.5 times the operating wavelength; the spacing between the seventh in-line antenna array and the eighth in-line antenna array is 2.5 times the operating wavelength. ;
The vehicle side rear radar antenna area array according to claim 6, wherein the in-line antenna array is the antenna array according to any one of claims 1 to 5.