Combined polarity/capacity weighting of IDTs with constant length of electrodes for broadband SAW filters

This paper is devoted to providing high frequency selectivity of interdigital transducers (IDT) with constant length of parallel electrodes. For realization of needed time response the proposed technique uses combined weighting of IDTs structure by optimal assignment of polarities of individual electrodes (polarity weighting) and by a voltage division between some parts of IDT (capacity weighting). The simulated and experimental characteristics are better than in case of using each of these weightings separately.