Fast method of solution for mixed electrostatic task in periodic arrays

The fast method of the solution of the mixed electrostatic task (MEST) for periodic system of electrodes on a plane with any degree of accuracy and for any electrostatic boundary conditions is described. Using the given method, it is possible to find charge density distribution P(x), voltage u(x), potential φ(x) and flux σ(x) on border of a plane, and also full charge of an electrode q_n IDT capacity and transfer function of IDT without acoustic reflections between electrodes. The method allows us to calculate electrical end effect with floating guard electrodes. The solution (MEST) for electrodes of different width (SPUDT) by imposing of an additional fine periodic array of electrodes which approximate electrostatic boundary conditions for tested initial electrodes of different width is described.