Radar sensor for motor vehicles

Patent metadata

Field	Value
Publication number	US-9638796-B2
Application number	US-201113977305-A
Country	US
Kind code	B2
Filing date	Nov 7, 2011
Priority date	Dec 29, 2010
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

A radar sensor for motor vehicles, having a transmitting antenna in the form of a planar group antenna having multiple antenna elements situated side by side on a shared planar substrate, and having a feed network and a switching device for supplying microwave power to the antenna elements. The antenna elements are situated at equal distances in at least one row; the feed network is designed for supplying the antenna elements with the microwave power having a phase shift which increases at constant increments from one end of the row to the other; and the switching device is designed for controlling the supply of the microwave power to the antenna elements in such a way that, depending on the operating mode, the supply is implemented in a mirror-inverted fashion from opposite ends of the at least one row.

First claim

What is claimed is:

1. A radar sensor for a motor vehicle, comprising:
a transmitting antenna in the form of a planar group antenna having multiple antenna elements situated side by side on a shared planar substrate, the antenna elements being situated at equal distances in at least one row;
a feed network for supplying the antenna elements with a microwave power signal, wherein the antenna elements are phase shifted so that the phases of the antenna elements increase by a constant increment between adjacent antenna elements from one end of the row to the other, wherein the same constant increment characterizes the phase shifts between every pair of consecutively adjacent antenna elements; and
a switching device to supply the microwave power signal to the antenna elements, and to control the supply of the microwave power signal to the antenna elements by switching between:
a first operating mode in which a radiation power varies among the antenna elements, and
a second operating mode in which the radiation power is swapped between corresponding antenna elements on opposite ends of the row, so that the radiation power is a mirror image of the radiation power in the first operating mode when plotted on an antenna diagram, wherein the radar sensor includes two rows of antenna elements, a separate feed network via which the microwave power signal is fed serially into the antenna elements being assigned to each one of the two rows, the feed devices for the two rows being diametrically opposed to one another, and wherein the switching device is formed by an oscillator having two outputs which can be switched on and off independently from one another, and wherein each of the feed networks is permanently connected to a respective one of the two outputs.

2. The radar sensor as recited in claim 1 , wherein a distance between adjacent antenna elements within each row amounts to one-half the wavelength of the emitted microwave radiation.

3. The radar sensor as recited in claim 1 , wherein the constant increment of the phase shift amounts to 120°.

4. A motor vehicle having a radar sensor, the radar sensor including a transmitting antenna in the form of a planar group antenna having multiple antenna elements situated side by side on a shared planar substrate, the antenna elements being situated at equal distances in at least one row, a feed network for supplying the antenna elements with a microwave power signal, wherein the antenna elements are phase shifted so that the phases of the antenna elements increase by a constant increment between adjacent antenna elements from one end of the row to the other, wherein the same constant increment characterizes the phase shifts between every pair of consecutively adjacent antenna elements, and a switching device to supply the microwave power signal to the antenna elements, and to control the supply of the microwave power signal to the antenna elements by switching between a first operating mode and a second operating mode, a substrate of the radar sensor forming a 45° angle with a longitudinal axis of the vehicle, wherein in the first operating mode, a radiation power varies among the antenna elements, and in the second operating mode, the radiation power is swapped between corresponding antenna elements on opposite ends of the row, so that the radiation power is a mirror image of the radiation power in the first operating mode when plotted on an antenna diagram, wherein the radar sensor includes two rows of antenna elements, a separate feed network via which the microwave power signal is fed serially into the antenna elements being assigned to each one of the two rows, the feed devices for the two rows being diametrically opposed to one another, and wherein the switching device is formed by an oscillator having two outputs which can be switched on and off independently from one another, and wherein each of the feed networks is permanently connected to a respective one of the two outputs.

5. The motor vehicle as recited in claim 4 , wherein two radar sensors of identical design are situated in a mirror-inverted fashion on opposite sides of the vehicle.

6. A driver assistance system for a motor vehicle, comprising:
a lane change assist system for position finding of vehicles on the same lane as the motor vehicle or an adjacent lane in the rear area of the motor vehicle;
a cross-traffic alert function for the position finding of vehicles which move transversely to a longitudinal axis of the motor vehicle; and
a radar sensor including a transmitting antenna in the form of a planar group antenna having multiple antenna elements situated side by side on a shared planar substrate, the antenna elements being situated at equal distances in at least one row, a feed network for supplying the antenna elements with a microwave power signal, wherein the antenna elements are phase shifted so that the phases of the antenna elements increase by a constant increment between adjacent antenna elements from one end of the row to the other, wherein the same constant increment characterizes the phase shifts between every pair of consecutively adjacent antenna elements, and a switching device to supply the microwave power signal to the antenna elements, and to control the supply of the microwave power signal to the antenna elements by switching between:
a first operating mode in which a radiation power varies among the antenna elements, and
a second operating mode in which the radiation power is swapped between corresponding antenna elements on opposite ends of the row, so that the radiation power is a mirror image of the radiation power in the first operating mode when plotted on an antenna diagram, wherein the operating modes are selectable with the aid of the switching device as a function of a desired assistance function, wherein the radar sensor includes two rows of antenna elements, a separate feed network via which the microwave power signal is fed serially into the antenna elements being assigned to each one of the two rows, the feed devices for the two rows being diametrically opposed to one another, and wherein the switching device is formed by an oscillator having two outputs which can be switched on and off independently from one another, and wherein each of the feed networks is permanently connected to a respective one of the two outputs.

7. The radar sensor as recited in claim 1 , wherein the first operating mode produces, based on first received radar echoes, a warning indicating a vehicle approaching from behind on the same lane or on an adjacent lane, and wherein the second operating mode produces, based on second received radar echoes, a warning concerning cross traffic.

8. The motor vehicle as recited in claim 4 , wherein the first operating mode produces, based on first received radar echoes, a warning indicating a vehicle approaching from behind on the same lane or on an adjacent lane, and wherein the second operating mode produces, based on second received radar echoes, a warning concerning cross traffic.

9. The driver assistance system as recited in claim 6 , wherein in the first operating mode, the lane change assist system produces, based on first received radar echoes, a warning indicating a vehicle approaching from behind on the same lane or on the adjacent lane, and wherein in the second operating mode, the cross-traffic alert function produces, based on second received radar echoes, a warning concerning cross traffic.

Assignees

• Binzer Thomas
• Waldschmidt Christian
• Hellinger Raphael
• Steinbuch Dirk
• Bosch Gmbh Robert

Inventors

• Binzer Thomas
• Waldschmidt Christian
• Hellinger Raphael
• Steinbuch Dirk

Classifications

• H01Q1/3233

  particular used as part of a sensor or in a security system, e.g. for automotive radar, navigation systems · CPC title

• G01S2013/9315

  Monitoring blind spots · CPC title

• G01S13/87

  Combinations of radar systems, e.g. primary radar and secondary radar · CPC title

• H01Q1/3283

  side-mounted antennas, e.g. bumper-mounted, door-mounted (mounted on windscreens H01Q1/1271) · CPC title

• H01Q25/002

  providing at least two patterns of different beamwidth; Variable beamwidth antennas · CPC title