Adaptive beamforming techniques are now widely used to reject interfer
ence (jammer/clutter) signals in radar, communication, and sonar appli
cations, In adaptive arrays using the sample matrix inversion (SMI) al
gorithm, inadequate estimation of the covariance matrix results in ada
ptive antenna patterns with high sidelobes and distorted mainbeams. In
this paper, a method is proposed to precisely control the peak (rathe
r than average) sidelobe level of adapted array patterns, The proposed
method is also generalized to adaptive array antennas with moderate b
andwidth and large random amplitude and phase errors, Theoretical anal
ysis and simulation results are provided to illustrate the performance
of the method proposed.