测量频率范围小于500KHz的前置放大器的相位增益曲线

我想测量频率范围小于500KHz的前置放大器的相位增益曲线，从0.2 uV开始放大。请建议我购买具有这些功能的合适仪器。



     以下为原文

  I want to measure Phase-Gain Curve of Pre-amplifiers with frequency range of less than 500KHz  

with amplitued starting from 0.2 uV ..

Kindly suggest me an appropiate Instrument to buy having these features..