Direct comparison between phase locked oscillator and direct resonance oscillator in the noncontact atomic force microscopy under ultrahigh vacuum

Abstract

I have demonstrated the advantage of the phase locked oscillator (PLO) over the conventional direct resonance oscillator (DRO) in noncontact mode atomic force microscopy (AFM) under ultrahigh vacuum. Direct comparison between PLO and DRO has been made in terms of background noise level, temporal response, and stability. Compared to the DRO method without phase coherence, the experimental results show that the PLO method is more effective in reducing the noise level and enhancing the stability over all force regimes in UHV noncontact AFM. The noise reduction and stability enhancement in PLO indicate the important role of the phase coherent effect in improving the capability of noncontact imaging in UHV.

Cantilever based optical interfacial force microscope

“…24 Figures 2͑a͒-2͑d͒ show that the feedback controller tries its best for the preamp output ͑V A-B ͒ to follow this square wave by applying appropriate voltages to the ZnO stack of the DMASP sensor ͑V ZnO ͒. The square wave causes the cantilever to create a torque on the cantilever so as to achieve a zero error voltage V error with the feedback on ͓Fig.…”

Design of a 41.14–48.11 GHz Triple Frequency Based VCO

“…where R p out and I ω 0 are the output resistance and the fundamental current, respectively. The noise of the L 2 and L 3 inductor is achieved in Equations (12) and (13), respectively.…”

“…PMUs are used to estimate the magnitude and phase angle of an electrical phasor quantity, like voltage or current, in the electricity grid. As shown in Figure 1, one of the main components of a PMU is the phase locked oscillator which uses voltage controlled oscillators [11,12]. Therefore, in order to design a wireless transceiver system and also make a bridge between actors including operators and assets in the electrical industry, designing voltage controlled oscillators with high performance is needed.…”

Cantilever-Based Optical Interfacial Force Microscopy

“…Kim, 2004). Figure 3(a)-3(d) shows that the feedback controller preamp output (V A-B ) follows this square wave by applying appropriate voltages to the ZnO stack of the DMASP sensor (V ZnO ).…”