论文信息 - Criterion for the minimum source distance at which plane-wave beamforming can be applied

Criterion for the minimum source distance at which plane-wave beamforming can be applied

An expression is derived which can be used to determine the extent of the near field for a given microphone array size and operating wavelength. This expression is based on the distortion of the near-field array response, and approximates the distance at which the magnitude response error due to plane-wave beamforming is 1 dB.

James G. Ryan

[1] F. Pirz. Design of a wideband, constant beamwidth, array microphone for use in the near field , 1979 .

[2] L. J. Ziomek. Three necessary conditions for the validity of the Fresnel phase approximation for the near-field beam pattern of an aperture , 1993 .