电容式微机械超声换能器的收发一体电路实现

Transceiver Integrated Circuit of Capacitive Micromachined Ultrasonic Transducer

电容式微机械超声换能器收发一体电路研究的难点为换能器模式的转换和高频微弱信号的检测。文中利用限幅原理设计了收发隔离电路,实现了换能器发射与接收模式的分离,并设计了基于跨阻放大的检测电路,实现了对高频微弱信号的提取,克服了以上难点。通过水下测试系统的搭建,对其进行实验验证,结果表明收发一体电路的检测精度可达到25 p F/s,同时该电路还具有良好的线性度和稳定性。

For transceiver integrated circuit of capacitive micromachined ultrasonic transducer,there were two difficulties.The first was the model of transducer converted,the second was to detect high frequency and weak signal.The paper used limiting principle to design transceiver isolation circuit which can make transmission mode and receiving mode separate.The paper designed a detection circuit based on the transimpedance amplifier to achieve extraction of high frequency and weak signal.The methods overcame the difficulties.Through the underwater construction of the test system,the circuit by experiment was tested and verified.The result shows that detection precision of transceiver integrated circuit reached 25 p F/s,at the same time,it was great that the circuit has good linear and stability.