Spatial Filtering Using A Higher-Order Differential Microphone Array

Abstract:
Beamforming techniques are applied in sensor array processing in order to achieve a directivity characteristic, the so-called beam pattern, allowing the sensor array to spatially distinguish received signals. In this contribution, an approach is presented where microphones arranged in symmetric polygons are used to build sinusoidal directivity patterns, serving as a set of orthogonal base beam patterns from which a desired directivity can be constructed by linear combination. Both the theoretical background of this technique and some example measurement results are discussed.