| 摘要 |
<p>PURPOSE:To make a detection highly sensitive and stable by transmitting a signal in the manner of making a frequency hopping based on an unsweeping pattern and receiving that pattern by means of detecting and synchronizing at the receiving side. CONSTITUTION:At the transmitting side, the frequency in the specified range is hopped and oscillated in the frequency hopping part based on the unsweeping pattern specified with the signal in the pattern generation part (a). This signal is transmitted or received among antennas (h) through a material (d) provided with a resonance circuit having the resonance frequency within the range. Then, at the receiving side, whether the synchronization is made or not at the beginning is decided in a synchronization detecting part (e), and the phase of the pattern in the pattern generation part (a') is changed by a control part (f) based on the synchronous signal. Then the pattern in the receiving side is fixed at the time when the synchronization is made, thereby the change of the received and detected output responding to an existence and a condition of the resonance circuit with the transmitting frequency is detected.</p> |
