Abstract: To improve the fast search capability of digital array radar in the Broad-Transmit Multi-Receive mode, an optimization method for search resources based on dynamic beamforming is proposed. First, to address the beam distortion problem in the angular domain, the beam search space is transformed into the direction cosine coordinate system to effectively combine beam pointing with scanning loss. A shaped beam model is established based on the analysis of energy requirements of each beam, and the expressions for the shape and directional gain of the shaped beam are derived based on the beam grid. Then, a joint optimization model of beam-dwell time is constructed with the objective function of minimizing the search frame period, which achieves fast search by dynamically adjusting the beam dwell time and beam shape. In addition, a targeted preprocessing strategy and solution method are designed. Finally, the effectiveness of the proposed optimization method is verified by simulation. Results show that the proposed dynamic beamforming method can achieve effective coverage of the airspace with a small number of beams, and the search frame period can be shortened by more than 32.35% compared with the conventional sequential beam-position scanning method. This paper provides a reference for the application of shaped beams in digital array radar systems.

Key words: Digital Array Radar, Search Frame Period, Broad-Transmit Multi-Receive, Dwell Time, Beamforming