| 摘要 |
An excitation signal generating unit which comprises a transmission signal generating unit (112), a transmission amplifier (121), and a first switch (131) generates excitation signals for frequency channels with different frequency bands, and transmits same from an antenna (150). Receiving signals of the respective frequency channels which are received with the antenna (150) are inputted into a receiving intensity detection unit (113). The receiving intensity detection unit (113) detects resonance echo signals from the receiving signals of the respective frequency channels, and detects a signal intensity thereof. An excitation control unit (111) controls the excitation signal generating unit so as to adjust the signal intensity of the excitation signals such that the signal intensity of the resonance echo signals falls to less than or equal to a level adjustment threshold (Thp). When the signal intensity of the resonance echo signals falls to less than or equal to the level adjustment threshold (Thp), a temperature detection unit (114) analyzes the frequencies of the resonance echo signals, and detects a physical quantity (temperature) from the frequency spectral peaks. |
