Ultra wideband Love wave devices employing Cu-grating/rotated YX LiNbO3-substrate structure

This 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 suggested that high performance resonators with very small capacitance ratio would be realised using Cu gratings of the thickness of several percent of wavelength. It was also suggested that in particular, on 15°YX-LiNbO₃-substrate structure, the spurious response due to Rayleigh mode could effectively be suppressed. An IDT-type one-port SAW resonator and ladder-type SAW filter were fabricated on the Cu-grating/15°YX-LiNbO₃-substrate structure, and their high performances are demonstrated with discussion.