Hybridly Integrated MEMS-IC RF Front-End for IoT with Embedded Filtering and Passive Voltage Amplification

Enabling Internet of Things (IoT) in harsh environments relies on improving battery life, which can be achieved using Wake-Up Receivers (WuRX) with high quality factor (Q) RF components. MEMS micro-acoustic RF resonators have been proposed as strategic components to provide large passive voltage amplification as well as noise and interference rejection, ultimately providing means to reduce system-level link budget and power-hungry cells count in the back-end circuitry. In this work, we present an integration effort of a high-Q MEMS with an IoT RF front-end. Integration issues are discussed first at simulation level, and then verified on an WuRX designed thanks to the integration of in-house fabricated FBAR resonator and commercial integrated circuits. The result is a compact IoT RF sensor operating at 820 MHz with an outstanding measured RF gain of 12 dB, a 3 dB bandwidth of 7 MHz and an out-of-band rejection of 23 dB. Communication test shows that digital bit streams are fully recoverable at –46 dBm RF power with zero error rate above that threshold.