摘要
Transistors are nonlinear devices, which can produce nonlinear distortion in amplifier while amplifying signals. For weak nonlinear distortion, the expressions of total harmonic distortion (THD), the second order intermodulation distortion(IM2 ), the third order intermodulation distortion(IM 3) and intercept point(IP 3) are deduced. With the aid of software Multisim, we simulate transistor common emitter amplifier, transistor common emitter amplifier with resistor in emitter, differential amplifier and differential amplifier with resistor between emitters. The simulational results and theoretical analyses are almost the same.
晶体管是非线性器件 ,在放大信号时会产生非线性失真。针对弱非线性失真 ,推导了总谐波人 ( TH D)、二阶互调失真 ( IM2 )、三阶互调失真 ( IM3)和截点 ( IP3)的表达式 ,借助于 Multisim软件 ,对晶体管共发放大器、发射极带反馈电阻的失发放大器、差分放大器和发射极间带反馈电阻的差分放大器进行了仿真 ,并与理论结果作了比较 ,结果令人满意。