Micro atomic frequency standards employing an integrated FBAR-VCO oscillating on the 87RB clock frequency without a phase locked loop
Micro atomic frequency standards employing an integrated FBAR-VCO oscillating on the 87RB clock frequency without a phase locked loop
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微原子频率标准采用集成 FBAR-VCO，在 87RB 时钟频率上振荡，无需锁相环
DOI：
10.1109/memsys.2018.8346655
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
T. Ido
中科院分区：
文献类型：
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作者：
M. Hara;Y. Yano;M. Kajita;H. Nishino;Y. Ibata;M. Toda;S. Hara;A. Kasamatsu;H. Ito;T. Ono;T. Ido
我们将 3.5 GHz 频段薄膜体声谐振器 (FBAR) 应用于压控振荡器 (VCO)，该振荡器被设计为小型原子频率标准 (AFS) 的本地振荡器。该频率基准代替笨重的石英谐振器可以实现具有芯片元件尺寸的AFS。通过使用3.5GHz频段的FBAR，直接生成87Rb跃迁时的时钟频率（fclock/2=3.42GHz），无需锁相环（PLL），从而降低了射频控制单元的成本、尺寸和功耗。此外，还开发了基于 MEMS 的铷气室，其中圆柱形腔的直径和长度均为 3 毫米。我们观察到相干群体捕获（CPT）共振。通过将 FBAR-VCO 合并到 CPT 系统的反馈环路中，实现了持续时钟操作，1 s 时的频率不稳定性为 2.1×10−11。
We applied a 3.5-GHz-band thin film bulk acoustic resonator (FBAR) to a voltage controlled oscillator (VCO), which is designed as a local oscillator of miniaturized atomic frequency standards (AFSs). This frequency reference instead of a bulky quartz resonator may enable an AFS with a chip component size. By using the 3.5-GHz-band FBAR, the clock frequency at the 87Rb transition (fclock/2=3.42 GHz) was directly generated without a phase locked loop (PLL), reducing the cost, size, and power consumption of the RF control unit. Also, MEMS based Rb gas cells were developed, where the cylindrical cavity was 3 mm in both diameter and length. We observed a coherent population trapping (CPT) resonance. By incorporating the FBAR-VCO into the feedback loop of the CPT system, a sustained clock operation was achieved with a frequency instability of 2.1×10−11 at 1 s.