熊显名,张海申,韩家广,杜亮亮.太赫兹测试系统中锁相放大电路的设计[J].电测与仪表,2017,54(7):. xiongxianming,zhanghaishen,hanjiaguang,duliangliang.The design of phase locked amplifier circuit in Terahertz test system[J].Electrical Measurement & Instrumentation,2017,54(7):.
太赫兹测试系统中锁相放大电路的设计
The design of phase locked amplifier circuit in Terahertz test system
In order to solve the problem that the phase locked amplifier used in terahertz time domain spectroscopy (TDS) is convenient to carry and extract the weak signal of the electric field intensity of THz wave, a design scheme of phase locked amplifier is proposed based on cross correlation principle .The weak signal of the output of the chopper is sent to the AD630 signal terminal through the preamplifier,and with the coherent reference signal though the phase shift circuit is sent to the AD630 reference terminal.After phase lock, the voltage is converted into DC voltage by low pass filter.The experiment results show that the design of phase amplifier circuit has good linearity,can millivolt signal to noise radio of -30dB extracted,can be used for the detection of the Terahertz weak signal in strong background noise.
