Investigation of diffraction compensation at the trap positions for TV SAW filters

Firstly, wide band diffraction compensation methods are reviewed. Eight algorithms are formulated, implemented, and tested for evaluating their performance. Secondly, the angular spectrum of waves (ASoW) model for diffraction analysis is derived and validated by comparing measurements and analysis results. Finally, the most robust compensation algorithm is applied with the ASoW analysis program to design SAW filters. Both internal reflections and end effects are considered in the analysis and compensation programs. This paper also demonstrates that the ASoW model is superior to parametric diffraction models such as the parabolic approximation model as far as formulation, implementation, calculation speed, and the generality are concerned