A piezo-resistive resonant MEMS amplifier

Piezoresistive ring-shaped MEMS resonator

“…By integrating x and ε over the electrode length and the piezoresistive region, respectively, the relation between average strain and average displacement of the beam can be established: (1) in which ε is the average strain in the y-direction along the piezoresistive region; c x is the average displacement of the beam in the direction perpendicular to the beam axis, along the electrode; and l eq is defined as the equivalent dog-bone beam length, which is used to make the small signal model of the ring resonator equivalent to that of the dog-bone resonator [3,4]. Definitions of the other parameters in (1) can be found in Fig.…”

“…It is therefore desired that operation of MEMS resonators in the nonlinear regime, especially in the instable regime, be avoided, which on the other hand limits the power handling capacity. We have previously reported a new class of MEMS resonators based on the piezoresistive readout principle [3,4]. In these devices, strain in the extensional vibration mode is converted into electrical signal using the piezoresistive effect of a globally doped silicon structure.…”

“…In these devices, strain in the extensional vibration mode is converted into electrical signal using the piezoresistive effect of a globally doped silicon structure. The devices have the form of a free-free beam structure [3] or a dog-bone-shaped structure [4], see Fig.1a. The effective impedance of these devices at resonance is orders of magnitude smaller than the impedance obtained using the common capacitive readout.…”

A Coupled Resonator for Highly Tunable and Amplified Mixer/Filter

“…Significant efforts have been dedicated to improve the signal-to-noise ratio by mechanical amplification of the signal prior to the electronic amplification. Most of the explored methods in mechanically coupled resonators have relied mainly on parametric amplification, in which the mechanical amplification is achieved by exciting the pump beams at twice the resonance frequency (pump frequency) [1][2][3][4][5][6][7]. As a result, the small signal generated by one beam is amplified at the other beam through a weak coupler [1][2][3]6].…”

Nanoelectromechanical resonant narrow-band amplifiers

“…However, the majority of recent research on micromechanical resonant devices has focused on piezoelectric and capacitive resonators that are only passive electrical components. Such devices have not been able to meet the selectivity and pass-band loss requirements for wireless communications, leading researchers to turn their focus back to active on-chip resonant components, such as the resonant amplifier, which uses capacitive actuation and piezoresistive readout 2 . Recently, efforts were made to further combine the benefits of N/MEMS resonators with FETs.…”