A GENERIC APPROACH TO SYNTHESIZE OPTIMAL ARRAY MICROPHONE ARRANGEMENTS

The arrangement of microphones in an array does have a strong influence on the properties of the beamforming result. These properties are usually characterized by the beam width and the maximum side lobe level. Depending on the intended application of the array it is desirable to use microphone arrangements only that provide optimal properties using a given number of microphones. There have been several approaches in the past that rely on numerical methods to find optimal locations for all microphones in a planar array. The paper introduces a new method that does not require a numerical optimization. First, some general topological properties of any arrangement are considered. Then, the theory for continuous arrays (with infinite number of microphones) is revisited. This is used as a basis to develop a generic two-parameter approach that synthesizes array microphone arrangements. Finally, it is shown that this approach leads to Pareto-optimal arrangements and results are compared to those of other commonly used microphone arrangements.