Improved analysis for string and block weighted tapered SAW transducers

An improved COM analysis for string and block weighted tapered transducers is presented. The shortcomings of the previously reported analysis are discussed and the remedies are proposed. The improvement is made in COM parameter calculation. In particular, the charge distribution on transducer electrodes is calculated more accurately due to the changes made in the electrostatic problem formulation and solution. As a result, a better accuracy of the transduction and capacitance calculation is achieved. It is shown that the assumptions made in when calculating potential on the electrodes connected to floating busbars can increase the discrepancy between simulated and measured responses. The details of the electrostatic problem formulation and solution are presented. Experimental data are shown for the devices built on LiNbO₃, which demonstrate improved agreement between calculated and measured responses.