| 摘要 |
An improved microwave resonant cavity accelerometer (10) includes a reentrant microwave resonant cavity. Preferably, the accelerometer includes first and second complementary reentrant microwave resonant cavities (12, 13), each being characterized by a nominal resonant frequency. Each cavity (12, 13) includes a capacitive gap (36), and an inductive gap (38) surrounding each capacitive gap (36). A coupler couples to each cavity a microwave signal substantially at the nominal resonant frequency of each cavity (12, 13). In response to an acceleration force along a sensing axis (15), a proof mass (14) positioned along the sensing axis (15) differentially changes the dimensions of each cavity (12, 13) and establishes a resonant frequency for each cavity (12, 13) which varies as a function of the acceleration force. The accelerometer (10) includes means for detecting electromagnetic energy in each cavity (12, 13) and determining the frequency of the detected energy. The shift in resonant frequency is used to determine the acceleration of the proof mass (14). By using reentrant cavities (12, 13), the sensitivity of the accelerometer (10) to an acceleration of the proof mass (14) is improved by a factor of about 100 for miniaturized proof masses. The accelerometer (10) may be fabricated using micromachining techniques.
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