Wideband Love wave filters operating in GHz range on Cu-grating/rotated-YX-LiNbO3-substrate structure

The paper discusses the application of Love mode propagating on Cu-grating/rotated YX-LiNbO₃-substrate structure to the development of ultra-wideband and low-loss RF SAW filters. Theoretical analysis suggests that high performance resonators with very small capacitance ratio may be realised using Cu gratings of the thickness of several percent of wavelength. It was also suggested that, in particular, on a 15°YX-LiNbO₃-substrate structure, the spurious response due to the Rayleigh mode could effectively be suppressed. IDT-type one-port SAW resonators and ladder-type SAW filters were fabricated on the Cu-grating/15°YX-LiNbO₃-substrate structure, and their high performances are demonstrated by discussion.