Capacitance and Field Distributions for Interdigital Surface-Wave Transducers

Abstract : A boundary-shift technique used in conjunction with relaxation solutions of Laplace's equation allows the convenient numerical evaluation of the potential in the neighborhood of interdigital comb structures. With this method, the area of computation in the unbounded problem can be restricted to the region of interest near the electrode and interface surfaces. Because of the point-by-point nature of the calculation, a wide range of geometries can be studied with the inclusion of the effects of finger thickness and shape, and of any layers present. Capacitance values for many single interface and layered configurations of surface-wave transducers are presented along with a few representative examples of potential and field maps. (Author)