CW-powered squegging micromechanical clock generator

Abstract

A mechanical circuit has been demonstrated that harnesses squegging to convert −50dBm of input continuous-wave (CW) energy into a local 1-kHz clock output while consuming three orders less local battery power than a typical real-time clock (RTC). Unlike a previous clock receiver that relied on a modulated RF input, this clock generator converts a CW input — no modulation needed — to a clock output via squegging of an impacting micromechanical resonant switch (“resoswitch”). Here, impact-induced disruption compels the device's resonating element to lose oscillation amplitude (hence stop impacting), then recover to impact again, only to again lose amplitude, in a periodic and repeatable fashion. The resulting time domain waveform, with periodic peaks and valleys, then provides a stable frequency that serves as a local on-board clock for low data rate applications. By dispensing with the need for a positive feedback sustaining amplifier, this CW-powered mechanical clock generator operates with only 0.8nW of battery power when outputting a triangle-wave into 0.8pF, which is 1250× lower than the μW of a typical RTC.