Azimuth detecting apparatus and radar apparatus

• US 7,924,214 B2
• Filed: 06/08/2009
• Issued: 04/12/2011
• Est. Priority Date: 06/10/2008
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Ando, Takamasa
• Primary Examiner(s): Sotomayor; John B
• Application Number:
  US12/455,851
• Publication Number:
  US 20090303105A1
• Time in Patent Office: 673 Days
• Field of Search: 342 70- 72, 342/90, 342107-108, 342/111, 342/113, 342/116, 342/133, 342/139, 342146-147, 342/156
• US Class Current: 342/70
• CPC Class Codes: G01S 13/345 using triangular modulation
• CPC Class Codes: G01S 13/4463 using phased arrays
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/93185 Controlling the brakes
• CPC Class Codes: G01S 2013/9319 Controlling the accelerator
• CPC Class Codes: G01S 2013/932 using own vehicle data, e.g. ground speed, steering wheel direction
• CPC Class Codes: G01S 2013/9325 for inter-vehicle distance regulation, e.g. navigating in platoons
• CPC Class Codes: G01S 2013/93271 in the front of the vehicles
• CPC Class Codes: G01S 3/74 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 Class Codes: H01Q 21/0037 linear waveguide fed arrays

Abstract

In an azimuth detecting apparatus, a receiver includes antenna elements arranged at predetermined intervals d. A first signal producer produces, based on reception signals generated by the antenna elements, first signals which are equivalent to signals generated by antenna elements arranged at first intervals d1, d1 being an integral multiple of d. A second signal producer produces, based on the reception signals, second signals which are equivalent to signals generated by antenna elements arranged at second intervals d2, d2 being an integral multiple of d and greater than d1. A first azimuth detector detects, within a first azimuth detection area whose angular range is defined by d1, the azimuth of the target based on the first signals. A second azimuth detector detects, within a second azimuth detection area whose angular range is defined by d2, the azimuth of the target based on the second signals.

Claims

1. An azimuth detecting apparatus comprising:

a transmitter that transmits a continuous wave;

a receiver including a plurality of antenna elements that are arranged at predetermined intervals d, each of the antenna elements being configured to generate a signal upon receipt of a reflected continuous wave that is produced by the reflection of the continuous wave by a target;

a first signal producer that produces first signals based on the signals generated by the antenna elements of the receiver, the first signals being equivalent to signals generated by a plurality of antenna elements that are arranged at first intervals d1, where d1 is an integral multiple of d;

a second signal producer that produces second signals based on the signals generated by the antenna elements of the receiver, the second signals being equivalent to signals generated by a plurality of antenna elements that are arranged at second intervals d2, where d2 is an integral multiple of d and greater than d1;

a first azimuth detector that detects, within a first azimuth detection area whose angular range is defined by d1, the azimuth of the target based on the first signals produced by the first signal producer; and

a second azimuth detector that detects, within a second azimuth detection area whose angular range is defined by d2, the azimuth of the target based on the second signals produced by the second signal producer.

2. The azimuth detecting apparatus as set forth in claim 1, wherein the second signal producer produces the second signals by first converting the signals generated by the antenna elements of the receiver into digital signals and then processing the digital signals.

3. The azimuth detecting apparatus as set forth in claim 1, wherein in an array of the antenna elements of the receiver, adjacent m of the antenna elements located at one end of the array together make up a sub-array antenna, where m is an integer greater than or equal to 2,

the sub-array antenna directly synthesizes in analog form the signals generated by the m adjacent antenna elements to produce a synthetic signal, and

the sub-array antenna makes up part of the second signal producer to output the synthetic signal as one of the second signals.

4. The azimuth detecting apparatus as set forth in claim 3, wherein the second signal producer converts the signals generated by the antenna elements of the receiver other than the m adjacent antenna elements making up the sub-array antenna into digital signals, and synthesizes every m of the digital signals to produce one of the second signals.

5. The azimuth detecting apparatus as set forth in claim 4, wherein d1=d, and

each of the antenna elements of the receiver other than the m adjacent antenna elements making up the sub-array antenna makes up part of the first signal producer to output the signal generated by itself as one of the first signals.

6. The azimuth detecting apparatus as set forth in claim 5, wherein m=2, and d2=2×

d.

7. The azimuth detecting apparatus as set forth in claim 1, wherein d1=d, and

each of at least part of the antenna elements of the receiver makes up part of the first signal producer to output the signal generated by itself as one of the first signals.

8. A radar apparatus comprising:

a transmitter that transmits a continuous wave;

a receiver including a plurality of antenna elements that are arranged at predetermined intervals d, each of the antenna elements being configured to generate a signal upon receipt of a reflected continuous wave that is produced by the reflection of the continuous wave by a target;

a first signal producer that produces first signals based on the signals generated by the antenna elements of the receiver, the first signals being equivalent to signals generated by a plurality of antenna elements that are arranged at first intervals d1, where d1 is an integral multiple of d;

a second signal producer that produces second signals based on the signals generated by the antenna elements of the receiver, the second signals being equivalent to signals generated by a plurality of antenna elements that are arranged at second intervals d2, where d2 is an integral multiple of d and greater than d1;

a first azimuth detector that detects, within a first azimuth detection area whose angular range is defined by d1, the azimuth of the target based on the first signals produced by the first signal producer;

a second azimuth detector that detects, within a second azimuth detection area whose angular range is defined by d2, the azimuth of the target based on the second signals produced by the second signal producer;

a first range detector that detects the range of the target based on the first signals produced by the first signal producer;

a second range detector that detects the range of the target based on the second signals produced by the second signal producer; and

a target identifier that identifies the target based on both the azimuth of the target detected by one of the first and second azimuth detectors and the range of the target detected by one of the first and second range detectors.

9. The radar apparatus as set forth in claim 8, wherein the second signal producer produces the second signals by first converting the signals generated by the antenna elements of the receiver into digital signals and then processing the digital signals.

10. The radar apparatus as set forth in claim 8, wherein in an array of the antenna elements of the receiver, adjacent m of the antenna elements located at one end of the array together make up a sub-array antenna, where m is an integer greater than or equal to 2,

the sub-array antenna directly synthesizes in analog form the signals generated by the m adjacent antenna elements to produce a synthetic signal, and

the sub-array antenna makes up part of the second signal producer to output the synthetic signal as one of the second signals.

11. The radar apparatus as set forth in claim 10, wherein the second signal producer converts the signals generated by the antenna elements of the receiver other than the m adjacent antenna elements making up the sub-array antenna into digital signals, and synthesizes every m of the digital signals to produce one of the second signals.

12. The radar apparatus as set forth in claim 11, wherein d1=d, and

each of the antenna elements of the receiver other than the m adjacent antenna elements making up the sub-array antenna makes up part of the first signal producer to output the signal generated by itself as one of the first signals.

13. The radar apparatus as set forth in claim 12, wherein m=2, and d2=2×

d.

14. The radar apparatus as set forth in claim 8, wherein d1=d, and

each of at least part of the antenna elements of the receiver makes up part of the first signal producer to output the signal generated by itself as one of the first signals.