Design of Logarithmically Spaced Constant-Directivity Transducer Arrays

Abstract

An approach to array design is described which results in the construction of transducers with a frequency-independent directivity pattern. Frequency independence is achieved by truncating the effective array aperture in a frequency-dependent way. Logarithmic spacing of the transducers ensures maximum frequency coverage with a fixed number of transducers. This array design method can be used for microphone arrays as well as for loudspeaker arrays. Experiments with both a microphone and a loudspeaker array show that the predicted radiation patterns can be matched very closely in practice