Radar device for detecting or tracking aerial targets fitted to an aircraft

• US 8,258,997 B2
• Filed: 02/02/2010
• Issued: 09/04/2012
• Est. Priority Date: 02/02/2010
• Status: Active Grant

• Current Assignee: Thales SA
• Original Assignee: Thales SA
• Inventors: Kemkemian, Stéphane, Nouvel, Myriam
• Primary Examiner(s): Brainard, Timothy A
• Application Number:
  US12/698,987
• Publication Number:
  US 20110187581A1
• Time in Patent Office: 945 Days
• Field of Search: 342/29
• US Class Current: 342/29
• CPC Class Codes: G01S 13/426 Scanning radar, e.g. 3D radar G01S13/66 takes precedence
• CPC Class Codes: G01S 13/4463 using phased arrays
• CPC Class Codes: G01S 13/48 using multiple beams at emission or reception
• CPC Class Codes: G01S 13/93 for anti-collision purposes
• CPC Class Codes: G01S 13/933 of aircraft or spacecraft
• CPC Class Codes: G01S 2013/0245 Radar with phased array antenna
• CPC Class Codes: G01S 2013/0254 Active array antenna
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00
• CPC Class Codes: H01Q 3/24 varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching

Abstract

A radar device includes means for emitting microwave-frequency signals; means for receiving signals reflected by a target; computation means; a plurality of antenna systems disposed around the aircraft, an antenna system comprising a set of emission antennas coupled to the emission means and a set of reception antennas coupled to the reception means, each antenna system being dedicated to the coverage of a given angular sector Ω; for a given antenna system, the antenna beam on reception being formed by CBF by the computation means on the basis of the signals received by the reception antennas and the antenna beam on emission is pointed by an electronic scanning system in a number greater than or equal to two of directions inside the given angular sector Ω. The invention applies notably in the field of airborne radars, in particular radars with large angular coverage and short range that are necessary for example for carrying out a function of the “see and avoid” type on drones, which function is also commonly called “Sense & Avoid”.

Claims

1. A radar device for detecting and/or tracking aerial targets fitted to an aircraft, comprising at least:

means for emitting microwave-frequency signals;

means for receiving signals reflected by a target;

computation means;

a plurality of antenna systems disposed around the aircraft, an antenna system comprising a set of emission antennas coupled to the emission means and a set of reception antennas coupled to the reception means, each antenna system being dedicated to the coverage of a given angular sector Ω

, wherein

for a given antenna system, the computation means forming the antenna beam on reception by computational beamforming (CBF) on the basis of the signals received by the reception antennas and the antenna beam on emission is pointed by an electronic scanning system in a number greater than or equal to two directions inside the given angular sector Ω

, said antenna system comprising at least;

a set of P emission antennas, P being greater than or equal to 1, coupled to Q emission pathways, Q being greater than or equal to 1, the antennas being grouped into Q groups, each group being fed through an emission pathway;

an array of N reception antennas, associated with a number M of reception pathways, and

the electronic scanning system being composed of phase shifters with n states disposed in the emission pathways, the pathways being fed simultaneously through one and the same microwave-frequency signal, the orientation of the beam is dependent on the combination of the phase shifts on the various phase shifters;

the phase shifters are phase shifters with two states;

the orientation of the beam is obtained by binary combination of two microwave-frequency paths of different lengths upstream of power amplifiers; and

a phase shifter comprises a delay line and a switch in parallel.

2. The device according to claim 1, wherein the given angular sector Ω

is the search domain to be covered by the said device.