| 摘要 |
<p>PURPOSE:To improve long-distance detecting ability by selectively removing noises which have shorter width than a target signal to be extracted, and making the target signal not to drop in level and easily separating and extracting the fine target signal from noises. CONSTITUTION:A level setting circuit 5 supplies a reference voltage to comparators 6a, 6b, and 6c respectively and the outputs of those comparators are clocked for a constant time. Slicers 9a, 9b, and 9d slice the received signal of a receiving circuit 4 with levels supplied from a level setter 5. Namely, the slicer 9a extracts signals exceeding a voltage Va, the slicer 9b extracts signals between voltages Va - Vb, and the slicer 9c extracts signals below the voltage Vb. Then gate circuits 8a - 8c set the output signals of the slicers forcibly to 0 at intervals of clocked time obtained by timer circuits 7a, 7b, and 7c and send the signals to an adding circuit 109 as they are in other periods. Then the noises which have shorter width than the target signal are removed selectively and the target signal is separated from the noises.</p> |
