Accession Number : ADD007358

Title :   Beam-Former for FFT-Based Signal Processor.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Poole,Lynn A

Report Date : 08 Jul 1980

Pagination or Media Count : 9

Abstract : This report describes a beam-former for sampling and digitizing a sonar signal preparatory to Fast Fourier Transformer (FFT) processing comprising an array of ceramic sensors forming a series of rows and columns, a sampling transformer for each row and each column for sampling the weighted sum of the signals from the sensors in each row or column, a log compressor for each sampling transformer for compressing the amplitude of the sampled signal an analog-to-digital (A/D) converter circuit following each log compressor for sampling and digitizing the compressed signals under the control of a counting circuit so that the log compressor outputs are sampled at prescribed times in relation to each other so as to impart a time or phase shift to the digitized outputs to effect a beam tilting, a decompression circuit for decompressing the time shifted signals, an accumulator for adding the samples from each row and column, and a shifting circuit for shifting the accumulated signal up or down to make it compatible with the FFT circuit.

Descriptors :   *Patents, *Sonar signals, *Fast fourier transforms, *Signal processing, *Beam forming, Sampling, Analog to digital converters, Accumulators, Phase shift, Data compression

Subject Categories : Acoustic Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE