The inherent robustness of the H ~ algorithm in dealing with modeling disturbances is used to improve the performance of imperfect antenna array with the generalized sidelobe canceller structure. The modeling disturbances include sensor gain perturbation, initial condition error, and colored noise contamination. The influence of modeling disturbances, which is not involved in the recursive least squares (RLS) algorithm, is lumped into the estimation error minimization of the adaptive H ~ algorithm. Thus, an H ~ -based beamformer converges faster and is more robust to imperfect antenna array than an RLS-based beamformer. Computer simulation results have been provided to show the robustness feature of the proposed technique when applied to an imperfect antenna array.