P3O-3 Wideband Layer Mode Acoustic Devices on GaN/Sapphire Substrate

There exists SEZAWA mode on thin film GaN on Sapphire substrates. When the film thickness of GaN is selected at the condition thick enough to generate dual modes, the device has an interesting frequency response that the dispersion characteristics has the reverse polarity against that of the ordinal single mode of SEZAWA wave. In addition the bandwidth increases more than 1 order to that of the ordinal device with the single mode. This paper discusses the origin of these characteristics based on the experimental result and considers requirement for practical use