Development of a 6GHz resonator by using an AlN diamond structure

We have developed a diamond SAW resonator capable of over 3 GHz using a SiO
₂
/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 3 GHz compared to SiO
₂
/IDT/ZnO/diamond structures. A 2port 6.4 GHz resonator was fabricated and has successfully achieved a low insertion loss at 6.6 dB, a Q value of 450, and a low TCF. It was also found that the low propagation loss of SAW, 0.03 dB/wavelength, was achieved at 6 GHz using the AlN thin film as a piezoelectric material instead of the ZnO thin film.