A self-sustaining ultrahigh-frequency nanoelectromechanical oscillator

Abstract

In open-loop operation, this finely-tunable bridge circuit [S1] can deeply null the background response arising from parasitic effects and impedance mismatch to yield excellent signal-tobackground ratios (SBR's) of order ~5−10dB, on resonance. Various components for highresolution 180-degree-phase bridging and background nulling are also illustrated in the circuit diagram. Here R B is the resistance of a nanofabricated bridge resistor on chip (as shown in the inset of Fig. 1) -in practice it is often more convenient to employ another metalized nanobeam whose DC resistance is very close to the DC resistance of the resonator device of interest. This As demonstrated in Fig. S2, typical open-loop measurements of the UHF NEMS responses employing the circuit in Fig. S1 can yield SBR's of ~10dB. This represents a significant improvement over the SBR's of ~0.1−0.5dB typically obtained with the previous scheme [S2,S3] .

In-plane nanoelectromechanical resonators based on silicon nanowire piezoresistive detection

“…The noise (V Hz −1/2 ) was then measured by sweeping the frequency of the bias signal ω bias while keeping a constant offset frequency of ω/2π = 25 kHz. As a result, the high frequency Typically, 1/ f noise created by resistance fluctuations is the main limitation in piezoresistive sensors [9]. However, these resistance fluctuations were not observed in our devices at 20 MHz operating frequency.…”

“…For long time constant, the minimum Allan deviation reaches 6 × 10 −7 . This value is quite a classical one, reported in many papers (see [3,9,22] for example), and might be considered as the experimental limit.…”

“…This design results in a first-order piezoresistive effect (as opposed to a weaker second-order one like in [9]) with the suspended gauges acting as collectors of the stress F g /s, where s is the cross section area of the gauges. The strain induced in the gauges is transduced into a resistance variation R through the piezoresistive effect:…”

“…A lot of effort has been devoted to developing new transduction and background reduction [6]. A variety of NEMS detection techniques, such as capacitive [3,7,8], magnetomotive [9], piezoresistive [10,11] and field-emission [4,12] transduction, have been proposed. The magnetomotive approach typically requires large magnetic fields (2-8 T) and is thus not suitable for integrated applications.…”

Multichannel cavity optomechanics for all-optical amplification of radio frequency signals

“…Similar silicon micro-disk cavity with quality factor as high as 3 million has been reported in the literature 38 so it is possible to achieve even higher GF with a much lower power level. Although the operation speed of the device currently is limited by the relatively low mechanical frequency of the cantilevered signal waveguide, it is feasible to improve the mechanical frequency to the hundreds of megahertz range 39,40 , making it suited for radio-frequency (RF) photonics applications.…”