Feng X L, White C J, Hajimiri A, Roukes M L
Kavli Nanoscience Institute, MC 114-36, California Institute of Technology, Pasadena, California 91125, USA.
Nat Nanotechnol. 2008 Jun;3(6):342-6. doi: 10.1038/nnano.2008.125. Epub 2008 May 25.
Sensors based on nanoelectromechanical systems vibrating at high and ultrahigh frequencies are capable of levels of performance that surpass those of larger sensors. Nanoelectromechanical devices have achieved unprecedented sensitivity in the detection of displacement, mass, force and charge. To date, these milestones have been achieved with passive devices that require external periodic or impulsive stimuli to excite them into resonance. Here, we demonstrate an autonomous and self-sustaining nanoelectromechanical oscillator that generates continuous ultrahigh-frequency signals when powered by a steady d.c. source. The frequency-determining element in the oscillator is a 428 MHz nanoelectromechanical resonator that is embedded within a tunable electrical feedback network to generate active and stable self-oscillation. Our prototype nanoelectromechanical oscillator exhibits excellent frequency stability, linewidth narrowing and low phase noise performance. Such ultrahigh-frequency oscillators provide a comparatively simple means for implementing a wide variety of practical sensing applications. They also offer intriguing opportunities for nanomechanical frequency control, timing and synchronization.
基于在高频和超高频下振动的纳米机电系统的传感器，其性能水平超越了大型传感器。纳米机电装置在检测位移、质量、力和电荷方面已实现了前所未有的灵敏度。迄今为止，这些里程碑是通过需要外部周期性或脉冲刺激来使其进入共振的无源装置实现的。在此，我们展示了一种自主且自持的纳米机电振荡器，当由稳定的直流电源供电时，它会产生连续的超高频信号。该振荡器中的频率决定元件是一个428兆赫的纳米机电谐振器，它嵌入在一个可调谐电反馈网络中，以产生有源且稳定的自振荡。我们的纳米机电振荡器原型具有出色的频率稳定性、线宽变窄和低相位噪声性能。这种超高频振荡器为实现各种实际传感应用提供了一种相对简单的方法。它们还为纳米机械频率控制、定时和同步提供了引人入胜的机会。
