All-Mechanical Receivers

In today’s connected world, our lives depend heavily on information obtained from networks of sensor nodes and mobile devices. Billons of mobile devices are in communication over these networks at any given time. The trillion sensor vision calls for low-power, low-cost and small-sized wireless sensor nodes, posing ever-increasing constraints on the power consumption of wireless networks. Radio Frequency (RF) Microelectromechanical Systems (MEMS) offer one path towards nano-watt wireless communications.This dissertation presents the first demonstration of an all-mechanical wireless receiver that employs a micromechanical resonant switch (“resoswitch”) to consume zero quiescent power while listening and ~30nW while actively receiving. Here, high-Q mechanical resonance offers frequency selectivity, while mechanical impact switching provides amplification. The mechanical receiver successfully detects and demodulates (in an On-Off-Keying (OOK) fashion) Frequency-Shift-Keying (FSK)-modulated input signals down to -68dBm, a promising sensitivity for low-speed and low-power wireless applications. Because this receiver consumes no power while listening in standby, it obviates the sleep/wake cycles often used by low power sensor networks to save energy. It thus eliminates the need for continuously operating clocks that govern sleep/wake periods, thereby eliminating their power consumption.If on the other hand one prefers to use more conventional mote transceivers that consume tens of milli-watts when on, then the sleep/wake strategy is paramount to save energy, and the clock sets the power bottleneck. A commercially available real time clock (RTC) typically consumes 1µW of power, which is considerably more than the tens of nano-watts more applicable for giant sensor networks. Fortunately, even when not used as a wireless transceiver, the all-mechanical circuit herein provides a solution to the clock problem, as well.Specifically, the second part of this dissertation presents