VHF, UHF and microwave frequency nanomechanical resonators
VHF, UHF and microwave frequency nanomechanical resonators
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DOI：
10.1088/1367-2630/7/1/247
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发表时间：
2005-11-29
影响因子：
3.3
通讯作者：
Roukes, ML
中科院分区：
文献类型：
--
作者：
Huang, XMH;Feng, XL;Roukes, ML
利用单晶碳化硅（SiC）薄膜材料制作了基模谐振频率在甚高频（VHF）、超高频（UHF）和微波L波段的纳米机械谐振器，并结合平衡电桥读出电路，通过磁动势转换测量了谐振频率。对于由相同的膜制成的谐振器，我们测量了品质因数的频率依赖性（因此几何依赖性）。我们已经看到，随着频率的上升，品质因数稳步下降。这表明了在这种情况下箝位损耗的重要性。为了研究这种耗散源，在同一芯片上共同制造了一个自由-自由梁SiC纳米机械谐振器，该谐振器具有在相似频率下工作的双箝位梁谐振器。已进行器械测试，以直接比较其特征和性能。据观察，一个显着的改善品质因数是从自由自由梁设计。此外，从不同的芯片与不同的表面粗糙度的谐振器的研究中，我们发现的SiC薄膜材料的表面粗糙度和谐振器的品质因数之间有很强的相关性。此外，我们实验研究的涡流阻尼效应的背景下的磁动势transduction. In。一个高纵横比的SiC纳米线谐振器的制造和测试这项研究。了解耗散机制，从而提高这些谐振器的品质因数，是很重要的实现这些设备所承诺的应用。
Nanomechanical resonators with fundamental mode resonance frequencies in the very-high frequency (VHF), ultra-high frequency (UHF) and microwave L-band ranges are fabricated from monocystalline silicon carbide (SiC) thin film material, and measured by magnetomotive transduction, combined with a balanced-bridge readout circuit. For resonators made from the same film, we measured the frequency dependence (thus geometry dependence) of the quality factor. We have seen a steady decrease of quality factor as the frequency goes up. This indicates the importance of clamping losses in this regime. To study this source of dissipation, a free-free beam SiC nanomechanical resonator has been co-fabricated on the same chip with a doubly clamped beam resonator operating at similar frequencies. Device testing has been performed to directly compare their characteristics and performance. It is observed that a significant improvement in quality factor is attained from the free-free beam design. In addition, from studies of resonators made from different chips with varying surface roughness, we found a strong correlation between surface roughness of the SiC thin film material and the quality factor of the resonators made from it. Furthermore, we experimentally studied the eddy current damping effect in the context of magnetomotive transduction. A high-aspect ratio SiC nanowire resonator is fabricated and tested for this study. Understanding the dissipation mechanisms, and thus improving the quality factor of these resonators, is important for implementing applications promised by these devices.