| 摘要 |
PROBLEM TO BE SOLVED: To provide a distance measuring device capable of performing distance measurement by discriminating between a signal from an object and a signal reflected from a substance other than the object. SOLUTION: Fig. 1a illustrates constitution of a first transceiver 10 and Fig. 1b illustrates constitution of a second transceiver 20. The first transceiver 10 transmits two signals having different frequencies generated by a balanced modulator 106. The second transceiver 20 generates and transmits a third-order intermodulation wave from the two signals by a nonlinear device 122. The first transceiver 10 receives the third-order intermodulation wave to detect the phase difference. The distance from the first transceiver 10 to the second transceiver 20 is measured by the phase difference. Because the frequency of the signal transmitted by the first transceiver 10 is different from the frequency of the received signal (third-order intermodulation wave), it can be discriminated from the reflection wave from the substance other than the second transceiver 20, thereby preventing interference. COPYRIGHT: (C)2008,JPO&INPIT
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