Ultra-low-power and high sensitivity resonant micromechanical receiver

This paper describes the proposed architecture and the analytical optimization of an ultra-low-power and high sensitivity Resonant Micromechanical Receiver (RMR) to be used in wake-up radios. The proposed radio frequency (RF) system is composed of three different stages: (1) a piezoelectric resonator that provides for passive voltage amplification, impedance matching, and high-Q filtering; (2) a MEMS resonant demodulator that acts as an efficient envelope detector of the modulated RF signal; and (3) a low power trans-impedance amplifier (TIA) that amplifies the output current of the demodulator and triggers a latch rectifier. All the RF components except for the CMOS are passive, which drastically reduce the power required to detect the RF signature. The CMOS components are constrained to operate with a maximum power consumption of 10 nW, approximately equivalent to the leakage rate of a battery. We analyze the performance of the proposed system for input frequencies ranging between 50 MHz and 400 MHz, and a modulation frequency (equal to the frequency of the MEMS demodulator) of 20-100 kHz. Our investigation shows that by using high performance acoustic resonators based on thin-films of lithium niobate [1] operating around 100 MHz in conjunction with narrow-gap MEMS demodulators [2], our proposed RMR can attain a sensitivity of at least -80 dBm for a 50% OOK signal and consume only 10 nW.