Date Added: Sep 2011
Recent advances in silicon sensors and circuit technology have enabled various wireless sensing applications. The deployed wireless sensors are highly integrated with limited power sources to reduce cost. Systems relying on batteries or energy scavenging from the environment operate at low frequencies (sub-MHz) to save power. Nevertheless, most of functions are scheduled with a low duty-cycle to maintain long-lifetime operation. Power is then drawn by an oscillator to generate the reference frequency. As a critical part of the system, a low-power oscillator is required.