| 摘要 |
<p>PURPOSE:To eliminate disturbance waves by performing level comparison to set more than a low threshold value to be within a signal range from a normal target, and setting more than a high threshold value to be within a signal range for disturbance waves. CONSTITUTION:A level expected to be received as echo pulses from a target is set at more than a set value Vl of a low threshold reference voltage source LREF and less than a set value Vh of a high threshold value reference voltage source HREF, and a received signal of more than the set value Vh is determined to be a disturbance wave. A low comparator output signal El which appears solely first at a low threshold value comparator LCMP after a time when a transmission trigger pulse Vt is generated is determined to be a reflection echo pulse from the target, and a high comparator output signal Eh which appears first at a high threshold value comparator HCMP after a time when the transmission trimmer pulse Vt is generated is determined to be a disturbance wave from another device, where subsequent processes are taken.</p> |
