DESIGN OF LOGARITHMICALLY SPACED CONSTANT-DIRECTIVITY TRANSDUCER ARRAYS

An approach to array design is described which results in the construc tion of transducers with a frequency-independent directivity pattern. Frequency independence is achieved by truncating the effective array a perture in a frequency-dependent way. Logarithmic spacing of the trans ducers ensures maximum frequency coverage with a fixed number of trans ducers. 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.