In this paper, we propose a set of constraints for adaptive broad-band beamforming in the presence of angular errors. We first present spatial and frequency derivative constraints (SFDC) for the design of the quiescent beamformer response. With the wavelet-based blocking matrices, the proposed generalized sidelobe canceller (GSC) preserves the desired signal, and it is less sensitive to the broad-band noise. To make this beamformer more robust to the directional mismatch, we add a pseudo-interference algorithm in the weight adaptive process. Analysis and simulation results demonstrate that the angular beamwidth is insensitive to the input signal-to-noise ratio (SNR).