| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a radio-wave range finder in which the level of a correction wave signal and that of a reflected signal are controlled to be always equal, in which an error is small irrespective of a distance to be measured and whose measuring accuracy is high. SOLUTION: In a radio-wave range finder, a variable attenuator 23 which is connected across a pulse transmission part 12 and a receiving antenna 21 and which outputs correction waves rd is provided, a first time detection circuit 32 to which reflected-signal supplementary pulses R" and reference pulses P are inputted so as to detect their time difference, and which outputs a measuring voltage Vb =ηtb corresponding to the time difference is provided, a second time detection circuit 332 to which correction-wave supplementary pulses rd " and the reference pulses P are inputted so as to detect their time difference and which outputs a compensation voltage Vc corresponding to the time difference is provided, and a differential circuit 34 which detects the difference between the measuring voltage Vb and the compensation voltage Vc so as to output a distance voltage is provided.</p> |
