Accession Number : ADD018115
Title : Steerable Beamformer.
Descriptive Note : Patent, Filed 21 Sep 95, patented 11 Jun 96,
Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC
Personal Author(s) : Sullivan, Michael J ; D'Addio, Raymond E ; Moorcroft, Arthur L
Report Date : 11 Jun 1996
Pagination or Media Count : 14
Abstract : A transmitter for generating a steerable, variable frequency signal from an array of projectors. An analog signal to be transmitted is sampled, digitized and stored in a circulating memory. A delay storage circuit includes time delays for each projector for each of predetermined beam directions. The successive locations in the recirculating memory correspond to signals having a time correspondence at predetermined unit delays from the signal then at the input terminal. The delay storage unit then produces a reading address for recovering, for each of the projector drivers, a signal value corresponding to an appropriate delay for obtaining the desired steering angle with a constant beam width signal. Frequency sensing circuitry can further compensate the signals by assigning each to a frequency bin and utilizing that bin to further define the delay for each projector and control the amplitude of the signal being sent to each projector. The output from a linear array of transducers is steerable over the entire range and operates with a constant band width even with significant frequency variations.
Descriptors : *BEAM FORMING, *BEAM STEERING, *PATENTS, TIME INTERVALS, ORIENTATION(DIRECTION), TRANSDUCERS, LINEAR ARRAYS, BANDWIDTH, ANTENNA RADIATION PATTERNS, ANTENNA ARRAYS, ANALOG SIGNALS, READING, DELAY CIRCUITS
Subject Categories : Radiofrequency Wave Propagation
Distribution Statement : APPROVED FOR PUBLIC RELEASE