| e have developed a diamond SAW resonator capable of over 3GHz using a SiO2/IDT/AlN/diamond structure. The structure enables a thicker Al-IDT and a lower series resistance for the SAW resonator based on FEM calculation results. These attributes lead to low insertion loss for SAW devices over 3GHz compared to SiO2/IDT/ZnO/diamond structures. A 2port 6.4GHz resonator was fabricated and has successfully achieved a low insertion loss at 6.6dB, a Q value of 450, and a low TCF. It was also found that the low propagation loss of SAW, 0.03dB/wavelength, was achieved at 6GHz using the AlN thin film as a piezoelectric material instead of the ZnO thin film. |