Study of the Mainlobe Misorientation of the First-Order Steerable Differential Array in the Presence of Microphone Gain and Phase Errors

This letter studies the mainlobe misorientation problem of the First-Order Steerable Differential Array (FOSDA) in the presence of microphone gain and phase errors, whose response is constructed by a linear combination of monopole and two orthogonal dipoles using a four-element square array. It is shown that the mainlobe orientation of the FOSDA will be undesiredly reversed in the presence of microphone phase errors if the array directivity controlling parameter is less than the corresponding lower bound. In contrast, the effect of microphone gain errors makes little difference when the array directivity controlling parameter varies. Some numerical examples are presented to evaluate the theoretical analysis.