Recently we presented a parametric resonator which is constructed from a double-sided comb-drive transducer with an electrostatically floating rotor. That device had a natural frequency of ~2.3 kHz. In the present study we present a parametric resonator of the same type, but with a natural frequency of ~30 kHz, and a more compact design. The higher frequency is relevant for several applications, and the increased stiffness may contribute to enhancing fabrication yield. However, due to the more compact design, the electrostatic modulation of stiffness is less effective. Because of the drastic reduction of the ratio between modulated stiffness and average stiffness, the new resonator cannot be driven in high-order instability windows, without reverting to excessively high driving voltages. Since it could only be driven in the first instability window, the differential sensing signal is at the same frequency as the driving signal. This makes it difficult to distinguish between motional and feed-through currents. We demonstrate that the 3 ^rd harmonic of the differential current is unaffected by feed-through and is therefore preferable for sensing the device response. We show that this higher harmonic component of current, is a unique characteristic of the resonator, and it is not due to a nonlinear mechanical effect, such as Duffing stiffening. [2021-0032]

中文翻译：

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带有浮动转子的参数谐振器：具有更高刚度和紧凑设计的器件的传感策略

最近，我们提出了一种参数谐振器，它由带有静电浮动转子的双面梳状驱动换能器构成。该设备的固有频率约为 2.3 kHz。在本研究中，我们提出了一种相同类型的参数谐振器，但其固有频率为 ~30 kHz，并且设计更紧凑。更高的频率与多种应用相关，增加的刚度可能有助于提高制造产量。然而，由于更紧凑的设计，刚度的静电调制不太有效。由于调制刚度和平均刚度之间的比率急剧降低，新谐振器不能在高阶不稳定窗口中驱动，而不会恢复到过高的驱动电压。由于它只能在第一不稳定窗口中被驱动，所以差分感测信号与驱动信号的频率相同。这使得很难区分运动电流和馈通电流。我们证明了 3 差动电流的^rd谐波不受馈通的影响，因此更适合检测设备响应。我们表明，电流的这种高次谐波分量是谐振器的独特特性，它不是由于非线性机械效应，例如 Duffing 硬化。[2021-0032]