Optimum transmission beamforming on phase-only antenna arrays

The objective of optimum adaptive transmission beamforming on linear isotropic phase-only antenna arrays is to maximize the pointing directional gain with the constraints of phase-only control at the antenna elements and the imposition of nulls in the interference directions. A suitable cost function stemming from the interference nulling constraints and phase-only control is constructed, equivalent to the primary constraint optimization problem, and we formulate and solve the minimum cost problem via the phase-only conjugate gradient algorithm and quasi-Newton algorithm. Simulations show that this approach can null random interference with more flexibility, more depth in the jammer direction and less computational cost under assumptions that powerful interferences are within the phase-only arrays' antijamming ability and the penalty coefficient is properly selected.