| 摘要 |
<P>PROBLEM TO BE SOLVED: To detect a phase difference at a high speed between a traveling wave and a reflected wave, for example. <P>SOLUTION: A signal generation step is executed for generating generated signals S<SB>f1</SB>and S<SB>f2</SB>of the same frequency but different from each other by a first reference phase difference based on the traveling wave Sf and generating generated signals S<SB>r1</SB>and S<SB>r2</SB>of the same frequency and of the same phase based on the reflected wave Sr. A detection step is executed for detecting a relative phase difference D θ1 by mixing the generated signals S<SB>f1</SB>and S<SB>r1</SB>with each other and detecting a relative phase difference Dθ2 by mixing the generated signals S<SB>f2</SB>and S<SB>r2</SB>with each other. The generation step and the detection step are executed with respect to the traveling wave Sf and to the reflected wave Sr, true phase difference between which is known. Relative phase differences Dθ1 and Dθ2, then detected, are parallelized with true phase differences. Previously stipulated relative phase differences are compared with the phase differences Dθ1 and Dθ2 detected in the detection step, and true phase differences corresponding to the coincident phase differences Dθ1 and Dθ2 are determined to be phase difference between the two waves Sf and Sr. <P>COPYRIGHT: (C)2004,JPO |
