Digital and FM Demodulation of a Doubly Clamped Single‐Walled Carbon‐Nanotube Oscillator: Towards a Nanotube Cell Phone

Abstract

Electromechanical resonators are a key element in radio-frequency telecommunication devices and thus new resonator concepts from nanotechnology can readily find important industrial opportunities. Here, the successful experimental realization of AM, FM, and digital demodulation with suspended single-walled carbon-nanotube resonators in a field-effect transistor configuration is reported. The crucial role played by the electromechanical resonance in demodulation is clearly demonstrated. The FM technique is shown to lead to the suppression of unwanted background signals and the reduction of noise for a better detection of the mechanical motion of nanotubes. The digital data-transfer rate of standard cell-phone technology is within the reach of these devices.

Graphene Nanoelectromechanical Systems as Stochastic-Frequency Oscillators

“…7 The real part is given by the in-phase response to the drive, which we find based on eq. S43 to yield ℜ[z] = −Γ 0 sin φ .…”

Tunable mechanical coupling between driven microelectromechanical resonators

“…In contrast, the effective spring constant of the system is insensitive to either of them and changes only by ±0.5%. Finally, we show that the comb-drive actuator can be used to switch between different coupling rates with a frequency of at least 10 kHz.Micro-and nanoelectromechanical resonators have attracted much attention thanks to their potential application as sensors [1][2][3][4][5][6][7][8], filters [9][10][11], amplifiers [12,13], and logic gates [14], with frequencies varying from the kHz to the GHz range [15][16][17]. By applying tension, the resonance frequencies can be tuned in-situ [18][19][20].…”

A single active nanoelectromechanical tuning fork front-end radio-frequency receiver

“…Basic mixing and demodulation have been demonstrated with carbon based devices using both resonating [17,18] and non-resonating [19,20] configurations. However, low quality (Q-) factor, ultra-high vacuum and low temperature operation impose limitations.…”

“…with no dc drain bias, the FET channel can be represented as a conductance, which is a function of the small-signal drain voltage, the mechanical displacement, and the gate voltage. It can be shown [18] that the term after expansion responsible for frequency demodulation is according to…”

“…At an operating pressure of 0.1 bar, the best results were obtained for a frequency deviation of f ≈ 35 kHz (or β ≈ 2.3) which corresponded to the upper limit of linear operation (see figure 4(a)). For higher modulation indices, higher harmonic current components caused distortion in the output signal as described recently in the literature [18]. We used a commercial microphone pre-amplifier (supporting information available at stacks.iop.org/Nano/23/225501/mmedia) to attain a 400 mV peak-peak output signal and have recorded 5 s of Beethoven's sonata Pathétique (the Allegro).…”