BEHAVIOR OF LEAKY SURFACE-ACOUSTIC-WAVE PROPAGATION AT DISCONTINUOUS REGION OF PERIODIC GRATING

This paper describes the leaky surface acoustic wave (LSAW) propagatio n characteristics at a discontinuous region in a grating structure. Fi rst, the dispersion relation of LSAWs propagating under a multielectro de-type grating is analysed. Then, the LSAW propagation on the discont inuous region is characterised by simply assuming that the LSAW behavi our under periodic part of the structure is identical with that under a totally periodic grating structure. It is concluded that the phase l ag considerably decreases at the discontinuous region. This suggests t hat the energy storing effect may be weakened at the region where the periodic structure is broken. The simulation of one-port LSAW resonato rs shows that device performances are sufficiently evaluated only by t aking account of the constant phase lag for a simulation tool based on the coupling-of-modes theory.