Design of wide-band array with frequency invariant beam pattern by using adaptive synthesis method

Based on adaptive technique, a method for designing wide-band array with frequency invariant beam pattern is presented in this paper. For a given beam pattern, the entire design process can be completed automatically by a computer without deriving expressions of weight vector. The design process is divided into three steps: design the beamformer by numerical method at reference frequency and obtain the weight coefficient; within the operation frequency range, design the beamformer by adaptive simulation technique at other frequency points and obtain the weight coefficient under which the beam pattern is the same with the desired beam pattern; design FIR filter and evaluate the filter coefficient for a FIR filter frequency response specified by the weight coefficient of each channel. The proposed method can be applied to an arbitrary array and have no restriction on sensor patterns. This method is valuable in practical engineering.