A concave annular array design, based on phasor summation—Part I: Design methodology

A detailed method for the design of anular arrays based on phasor summation is developed. The net phase shift across each annulus obtained by phasor summation is a very important factor in the design of an annular array, and determines the strength of the signal received. The method presented in this paper allows the designer to evaluate the trade-offs in parameters such as the strength of the signal from each annulus, the efficiency of each annulus, and the depth of focus that would be achievable. A concave annular array has been fabricated according to this design method. A set of graphs are given for an actual design to illustrate how one may readily evaluate these trade-offs.