Low phase noise VCSO with diamond SAW resonators

L and S-band VCSOs with diamond SAW resonators have been developed based on Lesson's model. First, the crystallinity of diamond thin film required for high-frequency SAW resonators was characterized by Raman scattering and electron backscattering diffraction. From these measurements, it was found that the propagation loss of SAW was lowered in relatively degraded films having small crystallites, and preferential grain orientation. After optimizing CVD growth conditions, a 3.4 GHz diamond SAW resonator with low insertion loss and high Q-value has been successfully developed. Second, by using the diamond SAW resonators, and employing low temperature co-fired ceramics, L and S-band VCSOs with a low phase noise were successfully obtained