Vertical Line Array (VLA) Beam - Forming Algorithm with constant beam width.

The algorithm proposed is a beam-forming algorithm. Many beam-steering and beam-forming algorithms exist and they are all based on the control of delay times between the signals driving the loudspeakers of the line array; this kind of control produces a variable beam-width depending on steering angle and frequency. In our case beam width doesn't depend on frequency and steering angle because a specific beam forming technique was applied by shading the amplitudes of signals for each element of the array according to the frequency applied. Furthermore a weighting function was utilized for spatial windowing. Spatial windowing allows reduction of secondary lobes without varying the directivity of the VLA. The algorithm was simulated and the aliasing due to the finite nature of VLA was calculated. The measurement session's results demonstrate secondary lobes reduction. Simulations and measurements results are presented as polar diagrams.