Simultaneous Multibeam Application for Sparse Phased-MIMO Radar System

The sparse phased multiple-input–multiple-output (phased-MIMO) radar system, composed of separated subarrays, is highly applicable for multi-platform cooperative systems. Specifically, it effectively utilizes the wide transmit beam to rapidly cover the region of interest and shapes a receive beam with high angular resolution for precise target detection. However, due to the mismatch between transmit and receive beam width, the conventional one-transmit-one-receive mode is no longer suitable for sparse phased-MIMO radar system. This results in wasted detection information for remaining angles within the transmit main beam. In this paper, our focus lies on implementing a simultaneous multibeam application based on sparse phased-MIMO radar system. By minimizing the peak sidelobe level (PSL) of the virtual transmit-receive beampattern as an objective function while also considering mainlobe level restrictions and fixed nulling constraints at specific regions, we formulate a simultaneous multibeam optimization problem with only one emission. To efficiently tackle the resulting non-convex design problem efficiently, we propose an iterative optimization algorithm based on alternate direction method of multipliers (ADMM) framework, which decomposes complex constrained optimization problem into multiple simple subproblems and solving them iteratively. Numerical simulations are provided to assess the performance of the proposed algorithm in terms of the achieved beampattern under various constraints and parameter settings. Simulation results demonstrate that by controlling the phase and amplitude of digital domain receiving weights, sparse phased-MIMO radar can achieve low sidelobe simultaneous multibeam reception under a single transmission for high resolution target detection in monitoring areas.