| 摘要 |
<p>PURPOSE:To enable the detection of an object to be detected with high accuracy by extracting the reflected wave from said object, by adjusting the phase shift quantity of a reference wave by extracting phase difference from the product of a received reflected wave and the reference wave and removing the received signal component by the reflected wave from the surface of a medium. CONSTITUTION:The reference wave from the sine wave oscillator 1601 of a phase extractor 160 is multiplied by a received reflected wave by a multiplier 1603 through a phase shifter 1602 to be supplied to a sampling apparatus 1606, controlled by a detector 1605, through LPF1604. The phase shifter 1602 receives feedback control by the output of the apparatus 1606 to shift the phase of the reference wave so as to adjust the output of the apparatus 1606 to zero. The reflected component from the surface of the medium in the reflected wave is removed by the phase shift control of the reference wave and the reflected wave from the object to be detected is well extracted to detect the object in the medium with high accuracy.</p> |
