数字荧光示波器1GHz前置放大器的设计

Design of 1 GHz pre-amplifier for digital phosphor oscilloscope

系统通过采用高速差分运算放大器、程控衰减阵列模块、射频双向模拟开关等芯片相结合的方式,实现了低阻50Ω带宽1 GHz(-3 dB),高阻1 MΩ带宽500 M(-3 dB)并实现了2 mV/div～5 V/div衰减量程,系统还实现了自动量程控制,直流电平自动位移调零控制,最大限度降低了整个系统的失真和漂移,经国家检测中心测试,主要技术指标达到国外同类产品先进水平。

This system achieves the 1 GHz bandwidth（-3 dB） of 50 Ω and 500 M bandwidth（-3 dB） of 1 MΩ with the mode of chips combination of high-speed difference amplifier,RF bidirectional analog switch and programmable attenuator.And it realizes the attenuation range 2 mV/div to 5 V/div and auto-range control,auto-position zero control of DC level.It reduces the distortion and floating maximumly.Its main technical specifications reach to the advanced level in the same field around the world which is vertified by the center of the National Measurement Lab.