An in-line SAW resonator employs an asymmetric adjustment of the Bragg frequencies of the left outer reflector and right outer reflector where the degree of periodicity shift and the relative direction of the frequency shift are calculated to move the peaks of the acoustic standing wave trapped between the gratings to coincide with the optimized centers of transduction of one or more interdigital transducers (IDTs) without the need for undesirable breaks in the periodicity or the use of reflectionless IDTs.