Floating electrodes: additional opportunities for optimization of broadband polarity weighted SAW transducers

Due to a low sensitivity to diffraction, the substitution of apodized transducers by uniform-beam-profile polarity weighted IDTs gives an opportunity to minimize SAW filter sizes by reducing its aperture. Inclusion of floating electrodes into the structure of the polarity weighted transducer makes the weighting procedure more flexible for forming specified broadband frequency responses. An optimization algorithm and a software for broadband polarity weighted interdigital transducers including floating electrodes has been developed. A set of PW IDTs for SAW filters with bandwidths of 2-13% has been designed using this algorithm.