The design of beam-forming for broadband beam-steerable parametric array

This paper has discussed the simulation and analysis to beam-forming of broadband parametric array in both rectangle and loop transducer array conditions. The simulation result shows that with a condition of same elements N=9 and similar array size r_m=49mm, the main-lobe -3db beam width for difference frequency beam in rectangle array is about 6.3° (7.4° for the loop array) and the side-lobe amplitude is one percent less than the value of main-lobe peak (10% for the loop array). The rectangle transducer array is more effective in improving main-lobe directivity and inhibiting side-lobe amplitude. The method of element signal time-delay adopted to achieve parametric array beam-steering in rectangle transducer array in this paper, and the simulation and analysis about it are completed too. As a result of Beam-steering, the beam main-lobe turned to width more, its peak value of amplitude reduce obviously, and it doesn´t point to the direction which is planned to. The causations about these problems are discussed in this paper, and it is verified that these problems can be modified by adding more elements and increasing array sizes.