Beam former using bessel sequences

Abstract

A beam former, to be used with a circular array of N receiving elements, toreq.3, comprising a set of N discrete Fourier transform (DFT) devices, each one connected to one of the receiving elements, for taking a temporal discrete Fourier transform of the signals at each of the N receiving elements. Means are connected to the array of DFT devices, for connecting sequentially to each of the N devices. A reference function generator generates the sequence of terms ##EQU1## where the argument x is equal to the number of wavelengths in the circumference of the circular array at the frequency being processed, and M is several times greater than x. A means connected to the connecting means and to the reference function generator circularly convolves the signals, for example, acoustic signals, received from the connecting means and the function generator. The beam former may further comprise means connected to the convolving means for displaying the inverse discrete Fourier transform, and therefore the beam pattern.

Dependencies are inferred from the claim text.