A 750μW 1.575GHz temperature-stable FBAR-based PLL

A 1.575 GHz phase-locked loop (PLL) using a bulk acoustic wave resonator (FBAR) based VCO is presented. Close-in phase noise is suppressed by the loop, while high-offset noise is suppressed by the extremely high Q (>2000) VCO. This technique results in a 750 muW PLL with phase noise of -82 and -138 dBc/Hz at 1 kHz and 1 MHz offset, respectively. A temperature-compensated FBAR stack is described, allowing quartz locking over a -10 to 100degC temperature range.