Abstract
Abstract
In this study, a first shear horizontal (SH1) mode plate wave resonator for HF and wide-band filters was investigated. From FEM simulation, the SH1 mode plate wave exhibited a high phase velocity of 23 km s−1 and a high electro-mechanical coupling factor (k
2) of 37% on (0°, 85°, 0°) LiNbO3 (LN) with a thickness of 0.1λ (λ: wavelength). The SH1 mode resonator was fabricated on a 0.5–0.57 μm thick LN film. An 80 nm Al IDT electrode was formed with λ varied from 4–16 μm. Finally, 50 nm thick Al was deposited to form an electrically short bottom plane, which was required to generate a SH1 mode wave. The fabricated device exhibited a resonance frequency (f
r) of 2.24 GHz, an anti-resonance frequency (f
a) of 2.8 GHz, a wide fractional bandwidth (FBW) of 20%, an impedance (Z) ratio of 35.4 dB, and TCF of −90.8 ppm/°C at f
r and −74.8 ppm/°C at f
a.