Digital beam forming using phased array architecture

Patent metadata

Field	Value
Publication number	US-8988278-B2
Application number	US-201213555814-A
Country	US
Kind code	B2
Filing date	Jul 23, 2012
Priority date	Jul 23, 2012
Publication date	Mar 24, 2015
Grant date	Mar 24, 2015

Abstract

A radar apparatus includes a receiver having a plurality of receiver channels, each including an antenna element, a phase shifter, and a switch. The antenna element provides a signal that passes through a phase shifter to a switch. The signal may then be passed to a summing element if the switch is closed. The summing element receives signals from the receive channels, and provides a sum signal to a mixer. In phased array mode, the switches are closed and antenna controller adjusts the phase angles of the phase shifters. In DBF mode, the phase shifters are maintained at a set value, and switches are operated sequentially to provide time-multiplexed signals from the receive channels to the summing element.

First claim

Having described our invention, We claim:

1. A radar system comprising:
a transmitter;
a receiver, including a plurality of receive channels, each receive channel including a receive antenna element, a phase shifter, and a switch configured to turn the receive channel on and off;
a summing element receiving signals from the receive channels;
a mixer receiving a sum signal from the summing element; and
an antenna controller adjusting phase angles of phase shifters in the receive channels, and configured to actuate the switch so as to turn on and off a respective receive channel,
wherein the antenna controller is further configured to operate the radar system in a phased array mode and digital beam forming mode, wherein in the phased array mode the antenna controller closes all switches at the same time and the phase shifters receive shift weightings, and wherein in the digital beam forming mode, the antenna controller sets all the phase shifters to a reference value, and the antenna controller sequentially turns each of the plurality of switches on and off so as to have only one of the plurality of receive channels on at any given time, wherein time-multiplexed signals from each receive channel turned on is collected by the summing element and processed so as to generate a digital beam after a predetermined number of receive channels is turned on and off.

2. The radar system of claim 1 , the radar system controller including a digital beam former operable to determine a virtual beam from the mixer signal when the radar system is in the digital beam forming mode.

3. The radar system of claim 2 , the digital beam former being provided by a digital beam forming algorithm executed by a processor in the radar controller.

4. The radar system of claim 3 , the digital beam forming algorithm being selected from a group of algorithms consisting of a MUSIC (multiple signal classification) algorithm and an ESPRIT (estimation of signal parameters via rotational invariant technique) algorithm.

5. The radar system of claim 1 , the electronic control circuit further including the phased array antenna controller and being operable to steer the receive beam.

6. The radar system of claim 1 , the antenna controller being operable to steer a real phased array receive beam when the radar system is in the phased array mode.

7. The radar system of claim 1 , the radar system being an automotive radar system.

8. A radar system, comprising:
a receiver, including a plurality of receive channels, each receive channel including a receive antenna element, a phase shifter, and a switch configured to turn the respective receive channel on and off, the antenna element providing an antenna signal that passes through the phase shifter to the switch, the receive channel providing a receiver signal to a summing element only
when the switch is closed, wherein the summing element receives receiver signals from the receive channels and provides a sum signal,
a mixer receiving the sum signal from the summing element;
an antenna controller configured to adjust phase angles of the phase shifters and to actuate the switch so as to turn a respective receive channel on and off,
the antenna controller further configured to operate the apparatus in a phased array mode and digital beam forming mode, wherein in the phased array mode the antenna controller closes all switches at the same time and the phase shifters receive shift weightings, and wherein in the digital beam forming mode, the antenna controller sets all the phase shifters to a reference value, and the antenna controller sequentially turns each of the plurality of switches on and off so as to have only one of the plurality of receive channels on at any given time, wherein time-multiplexed signals from each receive channel turned on is collected by the summing element and processed so as to generate a digital beam after a predetermined number of receive channels is turned on and off; and
a digital beam former configured to determine a virtual beam from the mixer signal when the radar system is in the digital beam forming mode.

Assignees

• Lee Jae Seung
• Schmalenberg Paul Donald
• Toyota Eng & Mfg North America

Inventors

• Lee Jae Seung
• Schmalenberg Paul Donald

Classifications

• G01S3/74

  Multi-channel systems specially adapted for direction-finding, i.e. having a single antenna system capable of giving simultaneous indications of the directions of different signals (systems in which the directions of different signals are determined sequentially and displayed simultaneously G01S3/04, G01S3/14) · CPC title

• H01Q3/30

  varying the {relative} phase {between the radiating elements of an array (H01Q3/2605, H01Q3/2658, H01Q3/2682, H01Q3/44 take precedence)} · CPC title

• G01S2013/9321

  Velocity regulation, e.g. cruise control · CPC title

• H01Q1/3233

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

• G01S13/931 Primary

  of land vehicles · CPC title