针对医用宽带超声小信号检测的不同效益需求，以分立元件、分立元件与集成运放结合、专用集成芯片3类可变增益放大电路为核心，分别给出不同类型的超声检测调理电路设计方案，并对其优缺点和适用范围进行了讨论。最后以PR5800超声收发器作为标准源，测试了基于放大器AD8334的实验电路，对脉冲超声信号进行放大和滤波，获得稳定的80 dB放大波形，并通过计算其信噪比换算了电路的输入噪声密度为0．7 nV／ Hz。所述电路能很好地达到80 dB最大增益、30 M Hz带宽＠80dB、输入噪声密度＜5 nV／ Hz的设计要求，为超声前端设计的成本、灵活度、方便性等问题提供了很好的参考。
Three classes of wideband and high-gain ultrasonic testing conditioning ci rcui ts design and comparison
For different effectiveness demands in wideband and small‐signal medical ultrasonic testing ,three classes of ultrasonic testing conditioning circuit designs are provided ,which mainly consist of discrete components type ,discrete components and integrated amplifiers combination type , specific integrated circuits type variable gain amplifier respectively .Moreover ,its advantages and disadvantages ,applicable scope are also discussed here .An experimental circuit based on the amplifier AD8334 was finally tested ,which were used to amplified ultrasound impulse and filtering to obtain a stable 80 dB amplification waveform ,as well as 0 .7 nV/ Hz input noise density according to the signal‐to‐noise ratio ,stipulating the ultrasound receiver/transmitter PR5800 as a standard source .The mentioned circuits can comply with the design requirements include achieving 80 dB maximum gain ,30 M Hz bandwidth@ 80 dB ,< 5 nV/Hz equivalent input noise voltage well . The program may provide some useful references in the aspects of cost , flexibility ,convenience concern in ultrasonic testing design .
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NSTL
万方数据
维普
