A method for analyzing periodic strips with apodization

Interdigital transducers applied in surface acoustic wave devices have fingers (conducting strips) of varying lengths defining the transducer apodization. Most theoretical papers neglect finite fingers' length in evaluation of the electric field in the transducer plane and the transducer's capacitance. This letter presents the generalized Blotekjaer, Ingebrigtsen, and Skeie's expansion analysis that may help in filling this gap in the transducer theory.