Resonant Microelectromechanical Receiver

This paper reports a practical demonstration of a proposed resonant microelectromechanical receiver for low power wake-up receiver (WuRx) applications. The proposed system is made of three main components: a piezoelectric based acoustic resonator, an electrostatically-driven MEMS resonant demodulator, and a CMOS baseband trigger circuit. The filtering, amplification, and demodulation of the incoming signal are performed through the piezoelectric resonator and the resonant demodulator, ensuring zero power consumption for both the radio frequency (RF) and mixing stages. The only power consumption occurs at baseband by operating the CMOS circuit in deep subthreshold. This system utilizes a lithium niobate piezoelectric resonator possessing a figure of merit of around 650 and achieving voltage gain of 28 dB. A resonant demodulator fabricated in the Epi-Seal MEMS process is utilized to attain a conversion efficiency of 13.8 nA/V
²
. In the trigger circuit, an amplifier with transimpedance 200 MQ is utilized to sense the output current from the demodulator. An intermediate buffer and a multiple stage passive latch rectifier are utilized to generate the wake-up signal through a Schmitt trigger. The demonstrated system achieves -40.2 dBm sensitivity for a 44 kHz amplitude-modulated 50 MHz RF signal while consuming 38.75 nW. This architecture is a promising step toward a WuRx capable of achieving higher interference rejection, high sensitivity, and nW range power consumption at a high data rate.