| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To increase accuracy of detecting the presence or absence or the condition of a target in a radio sensor. <P>SOLUTION: The radio sensor 100 radiates a transmission radio wave 124 of the order of GHz toward a target 108 intermittently with a switching frequency of about 1,000 Hz. An intermittent reflected/transmitted radio wave from the target 108 is received by a receiving antenna 110. An envelope signal which changes in a shape of a rectangular wave with the switching frequency of the reflected/transmitted radio wave is detected by a detection section 112. A DC component is rejected from the envelope signal by a bandpass filter 114, and only an AC component with the switching frequency of the envelope signal is extracted to be provided as an output signal 134. The output signal 134 has an amplitude which favorably reflects the amplitude of the reflected/transmitted radio wave. On the basis of the output signal 134, the presence or absence or the condition (for example, dryness condition when the target is the washing) of the target is decided. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
