Platform for JFET-based sensing of RF MEMS resonators in CMOS technology

This paper presents an RF MEMS resonator with embedded junction field effect transistor (JFET) for efficient electrical detection of the high quality factor acoustic resonance. A homogenous single-crystal silicon resonator is excited in its fundamental thickness extensional resonant mode at 1.61 GHz with a quality factor of 25,900. This device can be fully integrated into a typical SOI CMOS technology with minimal modifications to the existing front-end process. Furthermore, it achieves an acoustic transconductance of 171 μS at a bias current of 143 μA, approaching a practical range for monolithic, low-power RF systems.