It made use of the signal automatic gain control (AGC) and complex logical control to realize the precise measurement of the ultrasonic signal, and made use of the logical analytical method to realize double frequency and 160 MHz frequency of the counter.

• 利用超声波信号的自动增益控制 (AGC)和复杂的逻辑控制实现信号的精确测量 ; 利用逻辑分析实现倍频 ,使计数器的计数频率达到 16 0 MHz;