| 摘要 |
A mechanical quantity measuring apparatus is provided which can make highly precise measurements and is not easily affected by noise even when it is supplied an electricity through electromagnetic induction or microwaves. At least a strain sensor and an amplifier, an analog/digital converter, a rectification/detection/modulation-demodulation circuit, and a communication control circuit are formed in one and the same silicon substrate. Or, the silicon substrate is also formed at its surface with a dummy resistor which has its longitudinal direction set in a particular crystal orientation and which, together with the strain sensor, forms a Wheatstone bridge. With this arrangement, even when a current flowing through the sensor is reduced, measured data is prevented from being buried in noise, allowing the sensor to operate on a small power and to measure a mechanical quantity with high precision even when it is supplied electricity through electromagnetic induction or microwaves.
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