SAPPHIRE RESONATOR TRANSDUCER ACCELEROMETER FOR SPACE GRAVITY GRADIOMETRY
SAPPHIRE RESONATOR TRANSDUCER ACCELEROMETER FOR SPACE GRAVITY GRADIOMETRY
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DOI：
10.1088/0022-3727/27/4/031
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发表时间：
1994-04-14
影响因子：
3.4
通讯作者：
ROSEN, M
中科院分区：
文献类型：
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作者：
MARTIN, LP;SUTER, JJ;ROSEN, M
为最先进的微波位移传感器开发的技术可被纳入适用于空间惯性导航和测地研究应用的重力梯度计阵列。为了使这种系统有吸引力地安装在小型卫星上，它应该体积小、重量轻、坚固耐用，并在非低温下工作。一种有前途的技术是基于屏蔽蓝宝石微波谐振器的谐振频率的调制。在本实验中，蓝宝石谐振器工作在9.66 GHz附近的高阶（方位角模式数12）模式。空载品质因数为1.0 x 10（5），表明该模式可能不是纯回音壁模式，而是混合模式。蓝宝石调谐元件耦合到弹簧质量加速度计，具有接近16.8Hz的机械谐振，并且扰动谐振器的渐逝场的一部分。模式的谐振频率是谐振器和调谐元件之间的间隔的指数函数。本实验在310 K时得到最大Q（df/dx）= 3.91 × 10（2）MHz mum-1。在这种灵敏度水平下，当前的加速度计将需要df/f0 < 5 x 10（-10）来解决马克杯加速度。通过测量单边带噪声功率谱密度，确定了剩余相位噪声特性。
Techniques developed for state-of-the-art microwave displacement transducers may be incorporated into a gravity gradiometer array suitable for spatial inertial navigation and geodesic research applications. To make such a system attractive for placement into a small satellite, it should be small in size and weight, rugged, and operate at non-cryogenic temperature. One promising technique is based on the modulation of the resonant frequency of a shielded sapphire microwave resonator. In the present experiment, the sapphire resonator operates in a high-order (azimuthal mode number 12) mode near 9.66 GHz. The unloaded quality factor of 1.0 x 10(5) indicates that the mode is probably not a pure whispering gallery mode, but rather a hybrid. A sapphire tuning element is coupled to a spring-mass accelerometer, with a mechanical resonance near 16.8 Hz, and perturbs part of the evanescent field of the resonator. The resonant frequency of the mode is an exponential function of the spacing between the resonator and the tuning element. The present experiment yields a maximum Q(df/dx) = 3.91 x 10(2) MHz mum-1 at 310 K. At this level of sensitivity the current accelerometer would require df/f0 < 5 x 10(-10) to resolve mug acceleration. The residual phase noise characteristics were also determined by measurement of the single side band (SSB) noise power spectral density.