Since the robust beamformer based on a single uncertainty set constraints was susceptible to the norm constraint parameter

a novel robust broadband beamforming algorithm based on the double uncertainty set constraints was proposed.In the case that the practical steering vector is constrained to two spherical uncertainty sets with different model parameter

the proposed method effectively overcomes the SINR degradation problem of the robust beamformer based on a single uncertainty set constraints.Moreover

a necessary condition under which the D-WCRB algorithm achieves different SINR performance from the S-WCRB algorithm was derived.The choices of constraint parameter were also discussed.Finally

simulation results demonstrate the effectiveness of the proposed algorithm.