Green function analysis for SAW devices with arbitrary electrode structures

Green function, or boundary element, techniques are generally agreed to be the most satisfactory methods for rigorous SAW device analysis. Their direct application is however limited by their computational complexity, and, in the past, rigorous analyses have only been attempted for devices with very small numbers of electrodes. An algorithm has been devised that, with certain approximations, will allow a full Green function analysis to be performed relatively quickly on systems with more than 1000 electrodes. The approximations involve limiting short range interactions (electrostatic, etc.) to a certain number of nearest neighbour electrodes, and employing special representations for the long range (acoustic wave) terms. The computational complexity of the algorithm is O(N) for an N electrode structure, as opposed to O(N/sup 3/) for a simple approach.