| 摘要 |
PROBLEM TO BE SOLVED: To provide a sensor tag capable of transmitting temperature measurement results to other apparatus by a change in a transmission frequency in a non-contact manner.SOLUTION: A sensor tag includes: an antenna configured to send/receive a radio wave; rectification transistors connected with the antenna to take out a voltage from the radio wave that the antenna receives; a ring oscillator having a plurality of transistors driven by the voltage; and a resistor whose ohmic value changes in response to a temperature. The resistor is provided at the feedback part of the ring oscillator. The rectification transistors and the transistor of the ring oscillator are composed of a thin film transistor containing a coating type semiconductor in a semiconductor active layer. |
