ACTIVE RADAR SYSTEM AND METHOD

• US 20120146844A1
• Filed: 11/23/2011
• Published: 06/14/2012
• Est. Priority Date: 12/13/2010
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Stirling-Gallacher, Richard, Wang, Qi
• Granted Patent: US 8,797,208 B2
• Time in Patent Office: Days
• US Class Current: 342/189
• CPC Class Codes: G01S 13/34 using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal
• CPC Class Codes: G01S 13/343 using sawtooth modulation
• CPC Class Codes: G01S 13/87 Combinations of radar systems, e.g. primary radar and secondary radar
• CPC Class Codes: G01S 13/931 of land vehicles

Abstract

The present invention relates to an active radar system and a corresponding method. The proposed system comprises at least two transmit antennas that each transmits radiation to a scene as a transmit signal, said transmit signal comprising a series of frequency modulated pulses, at least one receive antenna that receives radiation from said scene as a receive signal, a controller that controls said at least two transmit antennas. The transmissions of the transmit signals are subsequently initiated with time offsets, controlled to be larger than the time delay between transmission of a first transmit signal of said two transmit signals and reception of radiation of said first transmit signal by said at least one receive antenna and to be smaller than the time duration of a complete frequency modulated pulse of said first transmit signal.

Claims

1. An active radar system comprising:

at least two transmit antennas that each transmits radiation to a scene as a transmit signal, said transmit signal comprising a series of frequency modulated pulses,

at least one receive antenna that receives radiation from said scene as a receive signal,

a controller that controls said at least two transmit antennas such that the transmissions of the transmit signals of the various transmit antennas are subsequently initiated with time offsets, which time offset between two subsequently initiated transmissions of transmit signals is controlled to be larger than the time delay between transmission of a first transmit signal of said two transmit signals and reception of radiation of said first transmit signal by said at least one receive antenna and to be smaller than the time duration of a complete frequency modulated pulse of said first transmit signal, and

a signal analyser that analyses said receive signal.

2. The active radar system as claimed in claim 1,

wherein said at least two transmit antennas are operable to each transmit identical transmit signals.

3. The active radar system as claimed in claim 1,

wherein said at least two transmit antennas are operable to each transmit a different transmit signal, in particular comprising pulses covering a different bandwidth and/or being differently frequency modulated.

4. The active radar system as claimed in claim 1,

wherein said controller is operable to control the time offset between two subsequently initiated transmissions of transmit signals to correspond to a frequency offset, which frequency offset is controlled to be larger than the frequency difference between a first transmit signal of said two transmit signals and reception of radiation of said first transmit signal by said at least one receive antenna due to the length of the signal path from said first transmit antenna to said at least one receive antenna and any movement of an object reflecting said first transmit signal.

5. The active radar system as claimed in claim 1,

wherein said controller is operable to use a fixed time delay between transmission of a first transmit signal of said two transmit signals and reception of radiation of said first transmit signal by said at least one receive antenna for the control of the time offset.

6. The active radar system as claimed in claim 1,

wherein said controller is operable to control at least one transmit antenna, in particular all transmit antennas subsequently, to transmit a transmit signal and wherein said signal analyser is operable to analyse the receive signal to determine the time delay between transmission of the transmit signal and reception of radiation of said transmit signal.

7. The active radar system as claimed in claim 1,

wherein said controller is operable to use a fixed time offset for controlling the transmission of two subsequently initiated transmissions of transmit signals.

8. The active radar system as claimed in claim 7,

wherein said controller is operable to use an identical fixed time offset for controlling all transmission of two subsequently initiated transmissions of transmit signals.

9. The active radar system as claimed in claim 1,

wherein said controller is operable to vary the time offset for controlling the transmission of two subsequently initiated transmissions of transmit signals.

10. The active radar system as claimed in claim 1,

comprising at least two receive antennas that each receives radiation from said scene as a receive signal, wherein said controller is operable to control the time offset between two subsequently initiated transmissions of transmit signals to be larger than the time delay between transmission of a first transmit signal of said two transmit signals and reception of radiation of said first transmit signal by said at least two receive antennas, in particular by all receive antennas.

11. The active radar system as claimed in claim 1,

comprising a plurality of transmit antennas and a plurality of receive antennas.

12. The active radar system as claimed in claim 11,

wherein antenna pairs, each antenna pair comprising a transmit antenna and a receive antenna, are arranged distant from each other, in particular at different directions from an object or a scene to be illuminated.

13. The active radar system as claimed in claim 11,

wherein the transmit antennas are arranged close to each other forming a transmit antenna array and the receive antennas are arranged close to each other forming a receive antenna array.

14. The active radar system as claimed in claim 1,

wherein said analyser comprises two or more mixers, in particular a mixer per transmit signal that is at least partly transmitted simultaneously or a mixer per transmit antenna, wherein a mixer is operable to mix the receive signal with the respective transmit signal to obtain a mixer output signal per mixer and a filter per mixer that filters the respective mixer output signal to obtain the contribution of the receive signal resulting from the respective transmit signal.

15. An active radar method comprising:

transmitting radiation to a scene as at least two transmit signals, each transmit signal comprising a series of frequency modulated pulses,

receiving radiation from said scene as a receive signal,

controlling the transmission of said at least two transmit signals such that the transmissions of the transmit signals of the various transmit antennas are subsequently initiated with time offsets, which time offset between two subsequently initiated transmissions of transmit signals is controlled to be larger than the time delay between transmission of a first transmit signal of said two transmit signals and reception of radiation of said first transmit signal by said at least one receive antenna and to be smaller than the time duration of a complete frequency modulated pulse of said first transmit signal, and

analysing said receive signal.

16. An active radar system comprising:

at least two transmission means for each transmitting radiation to a scene as a transmit signal, said transmit signal comprising a series of frequency modulated pulses,

at least one receiving means for receiving radiation from said scene as a receive signal,

a control means for controlling said at least two transmission means such that the transmissions of the transmit signals of the various transmission means are subsequently initiated with time offsets, which time offset between two subsequently initiated transmissions of transmit signals is controlled to be larger than the time delay between transmission of a first transmit signal of said two transmit signals and reception of radiation of said first transmit signal by said at least one receiving means and to be smaller than the time duration of a complete frequency modulated pulse of said first transmit signal, and

a signal analysis means for analysing said receive signal.