Transmission line modelling for array transducer elements

An improved KLM (Krimholtz-Leedom-Matthaei) model for medical ultrasound array transducer elements is proposed. The proposed approach involves the use of the symmetric fundamental Lamb wave modes as the primary mode of operation in all the layers. The idea is justified by comparing the calculated resonance frequencies of isotropic slabs with those obtained from coupled mode theory. Transducer sensitivities can be predicted within +or-1 dB and transducer center frequencies can be estimated within +or-50 kHz with the proposed modifications. In particular, the effect of kerf depth variations on the transducer characteristics can successfully be explained and predicted.