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”.