Rf-powered micromechanical clock generator

Abstract

A microelectromechanical resonant switch ('resoswitch') converts received radio frequency (RF) energy into a clock output. The resoswitch first accepts incoming amplitude- or frequency-shift keyed clock-modulated RF energy at a carrier frequency, filters it, provides power gain via resonant impact switching, and finally envelop detects impact impulses to demodulate and recover the carrier clock waveform. The resulting output derives from the clock signal that originally modulated the RF carrier, resulting in a local clock that shares its originator's accuracy. A bare push-pull 1-kHz RF-powered mechanical clock generator driving an on-chip inverter gate capacitance of 5 fF can potentially operate with only 5 pW of battery power, 200,000 times lower than a typical real-time clock. Using an off-chip inverter with 17.5 pF of effective capacitance, a 1-kHz push-pull resonator would consume 17.5 nW.