CN110208749B

CN110208749B - Reusable millimeter wave radar antenna array for automobile

Info

Publication number: CN110208749B
Application number: CN201910547512.2A
Authority: CN
Inventors: 何建中; 董吉
Original assignee: Qingneng Huabo Beijing Technology Co ltd
Current assignee: Qingsi Microelectronics (Nanjing) Co.,Ltd.
Priority date: 2019-06-21
Filing date: 2019-06-21
Publication date: 2021-07-20
Anticipated expiration: 2039-06-21
Also published as: CN110208749A

Abstract

The invention discloses a reusable automotive millimeter wave radar antenna array, and belongs to the field of automatic driving. The array consists of a subarray with a halving power divider and two subarrays with a trisecting power divider; the two trisection subarrays are respectively positioned at two sides of the bisection subarray; the sub-arrays are composed of longitudinal series microstrip antennas and microstrip power dividers. When the radar works in a short-distance mode, halving the subarray to work; when the radar works in a medium-distance mode, any one trisection subarray works; when the radar works in a long-distance mode, the three arrays work simultaneously; the switching of three working modes of the radar is realized in the chip; meanwhile, the radio frequency chip is provided with three same radio frequency output ends which are respectively connected to the three subarrays; the invention reduces the antenna area of the whole system by multiplexing the antenna in the unused mode, and the volume of the radar system is obviously reduced.

Description

Reusable millimeter wave radar antenna array for automobile

Technical Field

The invention belongs to the field of automotive millimeter wave radars, and particularly relates to a ranging radar microstrip antenna array.

Background

In recent years, the application of millimeter wave radar to autonomous driving has received increasing attention because it is not affected by temperature, environment, and weather conditions. Whether miniaturization, low cost and integration with the appearance of the automobile can be achieved becomes a key factor of the millimeter wave radar in the market of gradual automatic driving.

Currently, automotive millimeter wave radar systems generally employ a structure of three transmit channels and four receive channels. The four receiving channels are used for better obtaining the angle information of the detected object. In order to detect objects at different distances, namely far, middle and near, the three transmitting channels are connected with antennas with different gains. The higher the gain of the antenna, the greater the number of radiating elements required. The three antennas with different gains occupy a large area, and further affect the size of the radar system.

Disclosure of Invention

In view of the above, the present invention provides a reusable millimeter wave radar antenna array for an automobile, which is provided to overcome the disadvantages of the prior art.

The array is a series microstrip array in the longitudinal direction, and 8 identical series microstrip arrays are arranged in the transverse direction. In the transverse direction of the array, the left three serial microstrip antenna arrays are connected with the output end of the trisection power divider; the three series microstrip antenna arrays on the right side are connected with the output ends of the trisection power dividers; the middle two series microstrip antennas are connected with the output end of the halving power divider. The array can also be seen to be composed of three sub-arrays: one subarray with a halved power divider and two subarrays with a trisected power divider. The microstrip antenna and the microstrip power divider are composed of three layers of plates, and comprise: metal floor, high frequency dielectric and top metal.

For the array to work, the signals output from the chip should have the same amplitude and phase to the input of the power divider. While the chip has three output ports, each with the same phase and amplitude. When the radar works in a short-distance mode, halving the subarray to work; when the radar works in a medium-distance mode, any one trisection subarray works; when the radar works in a long-distance mode, the three subarrays work simultaneously; the switching of three working modes of the radar is realized in the chip;

the beneficial technical effects are as follows:

the invention enables the whole size of the system to be reduced by multiplexing the antennas under different modes. When the radar is operating in long range mode, the system multiplexes the short and medium range antennas. Compared with a general radar system mechanism, the invention reduces the occupied area of the short-distance and medium-distance antennas. At the same time, the addition of the three radio frequency signals at the antenna increases the output power of the system, thus increasing the detectable distance of the system. The reduction in the area of the radar system brings the benefits of reduced cost and increased integration with the vehicle.

Drawings

FIG. 1 is a schematic diagram of a reusable millimeter wave radar antenna array for an automobile according to the present invention;

FIG. 2 is a longitudinal series microstrip array according to an embodiment of the present invention;

FIG. 3 is a microstrip trisection power divider according to an embodiment of the present invention;

FIG. 4 is a microstrip bisection power divider according to an embodiment of the present invention;

FIG. 5 is an antenna pattern for a close range mode of operation according to an embodiment of the present invention;

FIG. 6 is an antenna pattern for the distance mode of operation in accordance with an embodiment of the present invention;

FIG. 7 is an antenna pattern for a long range operating mode in accordance with an embodiment of the present invention;

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention

The embodiment of the invention discloses a reusable automotive millimeter wave radar antenna array, which reduces the whole area of a radar system by multiplexing antennas in an unused mode. As shown in fig. 1, the array is a serial microstrip array in the longitudinal direction, and 8 identical serial microstrip arrays in the transverse direction. In the transverse direction of the array, the left three serial microstrip antenna arrays are connected with the output end of the trisection power divider; the three series microstrip antenna arrays on the right side are connected with the output ends of the trisection power dividers; the middle two series microstrip antennas are connected with the output end of the halving power divider. The array can also be seen to be composed of three sub-arrays: one subarray with a halved power divider and two subarrays with a trisected power divider. The microstrip antenna and the microstrip power divider are composed of three layers of plates, and comprise: metal floor, high frequency dielectric and top metal.

Optionally, in a specific implementation of this embodiment, the frequency of the main device is 77GHz, the material of the high-frequency dielectric plate is Rogers 3003, and the thickness of the high-frequency dielectric plate is 0.127 mm. The number of the series microstrip antennas is 12. The transverse center-to-center spacing of the series microstrip antenna is 2 mm.

Fig. 2 is a schematic diagram of a longitudinal series microstrip array according to an embodiment of the present invention. The series microstrip array consists of a feeder line and a microstrip antenna; wherein the feed lines have the same width of 0.14mm and different lengths. Table 1 shows the dimensions of the antenna, PL the length of the microstrip antenna, and PW the width of the microstrip antenna. Table 2 bit dimension of the feed line, L represents the length of the feed line,

TABLE 1

PL1	PL2	PL3	PL4	PL5	PL6
						1.173	1.137	1.112	1.09	1.08	1.07
PW1	PW2	PW3	PW4	PW5	PW6
						0.43	0.61	0.81	1.02	1.2	1.4

Unit: mm is

TABLE 2

L1	L2	L3	L4	L5	L6	L7
							1.257	1.28	1.257	1.23	1.199	1.163	1.14

Unit: mm is

Fig. 3 is a schematic diagram of a microstrip trisection power divider according to an embodiment of the present invention. The power divider is symmetrical left and right relative to the feed point. Wherein the width of the corner cut at the junction of L4 and L5 is 0.3 mm. Table 3 shows the specific dimensions of the microstrip trisection power divider.

TABLE 3

L1

L2

L3

L4

L5

L6

L7

0.3，0.3

0.58，0.5

0.73，0.2

1.03，0.3

2.55，0.3

0.6，0.18

1.13，0.3

(length, width) unit: mm is

Fig. 4 is a schematic diagram of a microstrip bisection power divider according to an embodiment of the present invention. The power divider is symmetrical left and right relative to the feed point. Table 4 shows the specific dimensions of the microstrip bisection power divider.

TABLE 4

L1	L2	L3	L4
				0.5，0.3	0.66，0.6	0.85，0.3	0.36，0.3

(length, width) unit: mm is

When the radar works in a short-distance mode, halving the subarray to work; when the radar works in a medium-distance mode, any one trisection subarray works; when the radar works in a long-distance mode, the three subarrays work simultaneously; the switching of three working modes of the radar is realized in the chip; meanwhile, the radio frequency chip is provided with three same radio frequency output ends which are respectively connected to the three subarrays.

The automotive millimeter wave radar antenna array in the embodiment enables the overall size of the system to be reduced by multiplexing the antennas in different modes. When the radar is operating in long range mode, the system multiplexes short and medium range antennas. Compared with a general radar system mechanism, the invention reduces the occupied area of the short-distance and medium-distance antennas. At the same time, the addition of the three radio frequency signals at the antenna increases the output power of the system, thus increasing the detectable distance of the system. The reduction in the area of the radar system brings the benefits of reduced cost and increased integration with the vehicle.

The previous description of the embodiments of the invention is provided to enable any person skilled in the art to make or use the present invention. Modifications to the present embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The reusable plane antenna array of the automotive millimeter wave radar is characterized in that a serial microstrip array is arranged in the longitudinal direction of the array, 8 identical serial microstrip arrays are arranged in the transverse direction, the serial microstrip arrays are of a symmetrical structure, and the serial microstrip arrays of the arrays are distributed in the transverse direction at equal intervals; in the transverse direction of the array, the left three serial microstrip antenna arrays are respectively connected with the output end of a first trisection power divider, the right three serial microstrip antenna arrays are respectively connected with the output end of a second trisection power divider, and the middle two serial microstrip antennas are respectively connected with the output end of a bisection power divider and are respectively called a first trisection power divider sub-array, a second trisection power divider sub-array and a bisection power divider sub-array; the first trisection power divider and the second trisection power divider are both symmetrical three-tooth fork-shaped structures; when the radar works in a close-range mode, the halving power divider subarray works; when the radar works in a medium-distance mode, the first trisection power divider subarray or the second trisection power divider subarray works; when the radar works in a long-distance mode, the first trisection power divider subarray, the second trisection power divider subarray and the bisection power divider subarray work simultaneously, wherein the bisection power divider, the first trisection power divider and the second trisection power divider are respectively connected with the output end of a radio frequency chip, and signals from the output end of the radio frequency chip to the trisection power divider, the first trisection power divider and the second trisection power divider have the same phase and amplitude; and the output ends of the radio frequency chip, the halving power divider, the first trisection power divider and the second trisection power divider which are connected have the same phase and amplitude.

2. The reusable automotive millimeter wave radar planar antenna array according to claim 1, wherein the bisection power divider, the first trisection power divider, and the second trisection power divider are each composed of microstrip lines.

3. The reusable automotive millimeter wave radar planar antenna array according to claim 2, wherein the main application scenario of the antenna array is automotive millimeter wave radar ranging.