Architecture for MEMS-based analogue demodulation

This paper presents a new method for the demodulation of radio frequency (RF) signals using an electrostatic actuator that acts as a mechanical mixer, directly converting RF signals into baseband signals in a homodyne receiver configuration. We investigate the feasibility of demodulating amplitude modulated and frequency modulated signals using the same electrostatic actuator numerically and experimentally. While exciting the actuator with the modulated RF signals, we measure the displacement of the actuator using a vibrometer at various frequencies. We present the operating principle of the micro-electro-mechanical systems (MEMS) demodulator as well as simulation and experiment results demonstrating its success in extracting the baseband signal from various RF signals. We have found that the displacement of the electrostatic actuator is 30.8 nm with a modulated signal input of 48.6 mV corresponding to 32 dB gain.