Exact inverse problem solution in digital beam former

The annular omnidirectional digital beam forming (DBF) system is proposed, into which the exact inverse problem solution algorithm is introduced. Because the DBF has an annular structure, a number of advantages accrue to the algorithm: (1) complete azimuthal data are efficiently observed, without window operations; (2) a much narrower beam that is 1/3 of the well-known limit of (wavelength)/(aperture size) can be obtained by implementation of an exact inverse solution; (3) an annular systolic array processor can be realized owing to the isoazimuthal feature of the beam forming algorithm. The concept and performance of the proposed DBF system are demonstrated theoretically. It is also shown experimentally that this DBF system can form 256 beams at one time, and a total of 65536 points are detected within 300 ms