5GHz low-phase-noise oscillator based on FBAR with low TCF

A 5 GHz oscillator with phase noise of -109.5 dBc/Hz at 100 kHz offset (more than 10 dBc/Hz better than the best LC oscillator and 4 dBc/Hz better than the best value reported in the literature) has recently been demonstrated with a 5 GHz Al/ZnO/Al/SiO/sub 2/ FBAR (film bulk acoustic resonator). The 5 GHz FBAR is fabricated through a simple, clean, and CMOS-compatible fabrication process, and is measured to have Q of about 300, K/sub t//sup 2/ of 4.3% and TCF (temperature coefficient of frequency) of -8.7 ppm//spl deg/C between 25 and 100/spl deg/C.