The fast calculation of the parameters of surface acoustic waves coupling of modes model

Accurate solutions of acoustic waves in piezoelectric substrate and metal film with layered structure were obtained. Phase velocity, electromechanical coupling constant and static capacitance were calculated based upon the solutions. Chen and Haus' theory was used to analyze surface acoustic waves in shorten gratings with single finger every period and a reflection coefficient expression of one strip was presented. Parameters of Al on X-112°Y LiTaO₃ and Au on ST-quartz were calculated. The results agreed well with those from Ken-ya Hashimoto's theory. The reflection coefficient of Au on ST-quartz was measured to verify the theoretical result.