Design of Robust Steerable Broadband Beamformers with Spiral Arrays and the Farrow Filter Structure

Abstract

This paper extends the design of steerable broadband beamformers by incorporating robustness in the design formulation to cater for microphone mismatches and other non-ideal characteristics. In our method, a 2 norm constraint on the filter weights is imposed in the design optimisation problem. This constraint limits the 2-norm of the filter weights, thus reducing the sensitivity of the beamformer towards the non-ideal characteristics of the microphones. Design examples and comparisons are presented to illustrate our approach.