Phase-Only Beamforming for Dual-Polarization Array Radar Based on Manifold Optimization

The phase-only beamforming (POB) technique manipulates the weighted phases of array antenna elements to create a desired radiation pattern, thereby reducing the hardware and power costs associated with large phased arrays. However, two significant challenges currently hinder the practical implementation of POB. First, the beam gain generated by POB can be severely distorted when a main lobe interference is present. Second, the POB method struggles to suppress interferences whose positions change within the spatial domain. To address these challenges, this letter proposes a novel POB method for dual-polarization array radar. This method incorporates polarization constraints on a Riemannian manifold under the condition of null broadening. By doing so, it generates robust nulls that can effectively suppress moving interferences in the main lobe and sidelobes while preserving the beam gain. Numerical simulations demonstrate that this method exhibits excellent anti-interference performance.