浅谈多级放大器设计中的几个问题

Discuss about some problems in the design of multistage amplifier

在一些电子设备中,常常要求放大电路的输出级能够带动一定的负载。因而要求放大电路有足够大的输出功率,因此对功率放大电路有以下几个要求:(1)根据负载要求,提供足够的输出功率;(2)具有较高的效率;(3)尽量减小非线性失真。一个多级放大器,无论如何复杂,总是由各种单级放大器组成的。要设计一个晶体三极管多级放大器,一般采用定性分析、定量计算和实验调整三者结合的设计方法。没有理论上的定性分析与定量估算,将是盲目的实践;但是,由于晶体管参数分散性大的特点,分析和计算不可能十分精确,只有通过实验调整才能使之完善起来。

In some electronic devices,often require the output stage amplifier circuit can drive a load.Thus amplifying circuit has a large enough output power,so the power amplifier circuit has the followingrequirements:(1) according to the load requirements,provide sufficient output power;(2) with high efficiency;(3) minimize the nonlinear distortion.A multistage amplifier,in any case is complex,always byvarious single stage amplifier.To design a crystal triode amplifier stage,the general design method of quantitative calculation and experimentaladjustment of qualitative analysis,the combination of the three.No qualitative and quantitative estimation theory,will be blind practice;however,due to the characteristics of large dispersion of transistor parameters,analysis and calculation may not very accurate, only perfect the adjustment to make up.